What is Plastic?|
What is plastic made of?
What is plastic made into?
Where does plastic come from?
What is a Polymer?
How are plastics made?
What is plastic made of?
Essentially, plastics are human-made, synthetic polymers made from long chains of carbon and other elements. Through a process called cracking, crude oil and natural gases are converted to hydrocarbon monomers like ethylene, propylene, styrene, vinyl chloride, ethylene glycol, and so on. These are then mixed with other chemicals to produce a desired finished product - plasticizers like phthalates to make PVC soft, butadiene to make plastic #7 tough, and many others. Additional additives include bacteria, heat, light, color, and friction. To create the desired form and shape of the plastic, the materials is finally cast, spun, molded, fabricated, extruded, or applied as a coating on another material.
What is plastic made into?
Plastics are everywhere in our lives - our kitchens, our vehicles, our purses, and even inside our own bodies. Check out the many ways plastics can be found all around you:
|Types of Plastics|
|List of Plastics Material (Updated)|
|Acrylonitrile Butadiene Styrene (ABS)|
|Acrylonitrile Ethylene Styrene (AES)|
|Acrylonitrile Styrene (AS)|
|Acrylonitrile Styrene Acrylate (ASA)|
|Biodegradable Polymers (Biodeg Polymers)|
|Cellulose Acetate (CA)|
|Diallyl Phthalate (DAP)|
|Expanded Polystyrene (EPS)|
|Liquid Crystal Polymer (LCP)|
|Maleic Anhydride Grafted Polymer (MAH-g)|
|Methyl Cellulose (MC)|
|Methyl Methacrylate (MM)|
|Polybutadiene Rubber (PBR)|
|Polyether Imide (PEI)|
Polyethylene (PE)Polythene |
LDPE - Low density polyethylene
HDPE - High density polyethylene
|Polylactic Acid (PLA)|
|Polyphenylene Ether (PPE)|
|Polyphenylene Sulfide (PPS)|
|Polyurethane Thermoset Elastomer (TSU)|
|Polyvinyl Chloride (PVC)|
|Styrene Acrylonitrile (SAN)|
|Styrene Acrylonitrile Silicone (SAS)|
|Styrene Maleic Anhydride (SMA)|
|Styrenic + Vinyl + Acrylonitrile (SVA)|
|Thermoplastic Elastomer (TPE)|
|Thermoplastic Polyurethane (TPU)|
|Thermoplastic, Unspecified (TP, Unspecified)|
|Thermoset Elastomer (TSE)|
|Vinyl Alcohol (VOH)|
What Is Plastic?|
A plastic is a type of synthetic or man-made polymer; similar in many ways to natural resins found in trees and other plants. Webster's Dictionary defines polymers as: any of various complex organic compounds produced by polymerization, capable of being molded, extruded, cast into various shapes and films, or drawn into filaments and then used as textile fibers.
A Little History
The history of manufactured plastics goes back more than 100 years; however, when compared to other materials, plastics are relatively modern. Their usage over the past century has enabled society to make huge technological advances. Although plastics are thought of as a modern invention, there have always been "natural polymers" such as amber, tortoise shells and animal horns. These materials behaved very much like today's manufactured plastics and were often used similar to the way manufactured plastics are currently applied. For example, before the sixteenth century, animal horns, which become transparent and pale yellow when heated, were sometimes used to replace glass.
Alexander Parkes unveiled the first man-made plastic at the 1862 Great International Exhibition in London. This material -- which was dubbed Parkesine, now called celluloid -- was an organic material derived from cellulose that once heated could be molded but retained its shape when cooled. Parkes claimed that this new material could do anything that rubber was capable of, yet at a lower price. He had discovered a material that could be transparent as well as carved into thousands of different shapes.
In 1907, chemist Leo Hendrik Baekland, while striving to produce a synthetic varnish, stumbled upon the formula for a new synthetic polymer originating from coal tar. He subsequently named the new substance "Bakelite." Bakelite, once formed, could not be melted. Because of its properties as an electrical insulator, Bakelite was used in the production of high-tech objects including cameras and telephones. It was also used in the production of ashtrays and as a substitute for jade, marble and amber. By 1909, Baekland had coined "plastics" as the term to describe this completely new category of materials.
The first patent for polyvinyl chloride (PVC), a substance now used widely in vinyl siding and water pipes, was registered in 1914. Cellophane was also discovered during this period.
Plastics did not really take off until after the First World War, with the use of petroleum, a substance easier to process than coal into raw materials. Plastics served as substitutes for wood, glass and metal during the hardship times of World War’s I & II. After World War II, newer plastics, such as polyurethane, polyester, silicones, polypropylene, and polycarbonate joined polymethyl methacrylate and polystyrene and PVC in widespread applications. Many more would follow and by the 1960s, plastics were within everyone's reach due to their inexpensive cost. Plastics had thus come to be considered 'common' - a symbol of the consumer society.
Since the 1970s, we have witnessed the advent of 'high-tech' plastics used in demanding fields such as health and technology. New types and forms of plastics with new or improved performance characteristics continue to be developed.
From daily tasks to our most unusual needs, plastics have increasingly provided the performance characteristics that fulfill consumer needs at all levels. Plastics are used in such a wide range of applications because they are uniquely capable of offering many different properties that offer consumer benefits unsurpassed by other materials. They are also unique in that their properties may be customized for each individual end use application.
Oil and natural gas are the major raw materials used to manufacture plastics. The plastics production process often begins by treating components of crude oil or natural gas in a "cracking process." This process results in the conversion of these components into hydrocarbon monomers such as ethylene and propylene. Further processing leads to a wider range of monomers such as styrene, vinyl chloride, ethylene glycol, terephthalic acid and many others. These monomers are then chemically bonded into chains called polymers. The different combinations of monomers yield plastics with a wide range of properties and characteristics.
Many common plastics are made from hydrocarbon monomers. These plastics are made by linking many monomers together into long chains to form a polymer backbone. Polyethylene, polypropylene and polystyrene are the most common examples of these. Below is a diagram of polyethylene, the simplest plastic structure.
Even though the basic makeup of many plastics is carbon and hydrogen, other elements can also be involved. Oxygen, chlorine, fluorine and nitrogen are also found in the molecular makeup of many plastics. Polyvinyl chloride (PVC) contains chlorine. Nylon contains nitrogen. Teflon contains fluorine. Polyester and polycarbonates contain oxygen.
Characteristics of Plastics
Plastics are divided into two distinct groups: thermoplastics and thermosets. The majority of plastics are thermoplastic, meaning that once the plastic is formed it can be heated and reformed repeatedly. Celluloid is a thermoplastic. This property allows for easy processing and facilitates recycling. The other group, the thermosets, can not be remelted. Once these plastics are formed, reheating will cause the material to decompose rather than melt. Bakelite, poly phenol formaldehyde, is a thermoset.
Each plastic has very distinct characteristics, but most plastics have the following general attributes.
1. Plastics can be very resistant to chemicals. Consider all the cleaning fluids in your home that are packaged in plastic. The warning labels describing what happens when the chemical comes into contact with skin or eyes or is ingested, emphasizes the chemical resistance of these materials. While solvents easily dissolve some plastics, other plastics provide safe, non-breakable packages for aggressive solvents.
2. Plastics can be both thermal and electrical insulators. A walk through your house will reinforce this concept. Consider all the electrical appliances, cords, outlets and wiring that are made or covered with plastics. Thermal resistance is evident in the kitchen with plastic pot and pan handles, coffee pot handles, the foam core of refrigerators and freezers, insulated cups, coolers and microwave cookware. The thermal underwear that many skiers wear is made of polypropylene and the fiberfill in many winter jackets is acrylic or polyester.
3. Generally, plastics are very light in weight with varying degrees of strength. Consider the range of applications, from toys to the frame structure of space stations, or from delicate nylon fiber in pantyhose to Kevlar®, which is used in bulletproof vests. Some polymers float in water while others sink. But, compared to the density of stone, concrete, steel, copper, or aluminum, all plastics are lightweight materials.
4. Plastics can be processed in various ways to produce thin fibers or very intricate parts. Plastics can be molded into bottles or components of cars, such as dashboards and fenders. Some plastics stretch and are very flexible. Other plastics, such as polyethylene, polystyrene (StyrofoamTM) and polyurethane, can be foamed. Plastics can be molded into drums or be mixed with solvents to become adhesives or paints. Elastomers and some plastics stretch and are very flexible. 5. Polymers are materials with a seemingly limitless range of characteristics and colors. Polymers have many inherent properties that can be further enhanced by a wide range of additives to broaden their uses and applications. Polymers can be made to mimic cotton, silk, and wool fibers; porcelain and marble; and aluminum and zinc. Polymers can also make possible products that do not readily come from the natural world, such as clear sheets, foamed insulation board, and flexible films. Plastics may be molded or formed to produce many kinds of products with application in many major markets.
6. Polymers are usually made of petroleum, but not always. Many polymers are made of repeat units derived from natural gas or coal or crude oil. But building block repeat units can sometimes be made from renewable materials such as polylactic acid from corn or cellulosics from cotton linters. Some plastics have always been made from renewable materials such as cellulose acetate used for screwdriver handles and gift ribbon. When the building blocks can be made more economically from renewable materials than from fossil fuels, either old plastics find new raw materials or new plastics are introduced.
Many plastics are blended with additives as they are processed into finished products. The additives are incorporated into plastics to alter and improve their basic mechanical, physical, or chemical properties. Additives are used to protect plastics from the degrading effects of light, heat, or bacteria; to change such plastic properties, such as melt flow; to provide color; to provide foamed structure; to provide flame retardancy; and to provide special characteristics such as improved surface appearance or reduced tack/friction.
Plasticizers are materials incorporated into certain plastics to increase flexibility and workability. Plasticizers are found in many plastic film wraps and in flexible plastic tubing, both of which are commonly used in food packaging or processing. All plastics used in food contact, including the additives and plasticizers, are regulated by the U.S. Food and Drug Administration (FDA) to ensure that these materials are safe.
There are several different processing methods used to make plastic products. Below are the four main methods in which plastics are processed to form the products that consumers use, such as plastic film, bottles, bags and other containers.
Extrusion - Plastic pellets or granules are first loaded into a hopper, then fed into an extruder, which is a long heated chamber, through which it is moved by the action of a continuously revolving screw. The plastic is melted by a combination of heat from the mechanical work done and by the hot sidewall metal. At the end of the extruder, the molten plastic is forced out through a small opening or die to shape the finished product. As the plastic product extrudes from the die, it is cooled by air or water. Plastic films and bags are made by extrusion processing.
Injection molding - In injection molding, plastic pellets or granules are fed from a hopper into a heating chamber. An extrusion screw pushes the plastic through the heating chamber, where the material is softened into a fluid state. Again, mechanical work and hot sidewalls melt the plastic. At the end of this chamber, the resin is forced at high pressure into a cooled, closed mold. Once the plastic cools to a solid state, the mold opens and the finished part is ejected. This process is used to make products such as butter tubs, yogurt containers, closures and fittings.
Blow molding - Blow molding is a process used in conjunction with extrusion or injection molding. In one form, extrusion blow molding, the die forms a continuous semi-molten tube of thermoplastic material. A chilled mold is clamped around the tube and compressed air is then blown into the tube to conform the tube to the interior of the mold and to solidify the stretched tube. Overall, the goal is to produce a uniform melt, form it into a tube with the desired cross section and blow it into the exact shape of the product. This process is used to manufacture hollow plastic products and its principal advantage is its ability to produce hollow shapes without having to join two or more separately injection molded parts. This method is used to make items such as commercial drums and milk bottles. Another blow molding technique is to injection mold an intermediate shape called a preform and then to heat the preform and blow the heat-softened plastic into the final shape in a chilled mold. This is the process to make carbonated soft drink bottles.
Rotational Molding - Rotational molding consists of a closed mold mounted on a machine capable of rotation on two axes simultaneously. Plastic granules are placed in the mold, which is then heated in an oven to melt the plastic Rotation around both axes distributes the molten plastic into a uniform coating on the inside of the mold until the part is set by cooling. This process is used to make hollow products, for example large toys or kayaks.
Durables vs. Non-Durables
All types of plastic products are classified within the plastic industry as being either a durable or non-durable plastic good. These classifications are used to refer to a product's expected life.
Products with a useful life of three years or more are referred to as durables. They include appliances, furniture, consumer electronics, automobiles, and building and construction materials.
Products with a useful life of less than three years are generally referred to as non-durables. Common applications include packaging, trash bags, cups, eating utensils, sporting and recreational equipment, toys, medical devices and disposable diapers.
7 MAJOR PLASTICS
Polyethylene Terephthalate (PET or PETE) is clear, tough and has good gas and moisture barrier properties making it ideal for carbonated beverage applications and other food containers. The fact that it has high use temperature allows it to be used in applications such as heatable pre-prepared food trays. Its heat resistance and microwave transparency make it an ideal heatable film. It also finds applications in such diverse end uses as fibers for clothing and carpets, bottles, food containers, strapping, and engineering plastics for precision-molded parts.
High Density Polyethylene (HDPE) is used for many packaging applications because it provides excellent moisture barrier properties and chemical resistance. However, HDPE, like all types of polyethylene, is limited to those food packaging applications that do not require an oxygen or CO2 barrier. In film form, HDPE is used in snack food packages and cereal box liners; in blow-molded bottle form, for milk and non-carbonated beverage bottles; and in injection-molded tub form, for packaging margarine, whipped toppings and deli foods. Because HDPE has good chemical resistance, it is used for packaging many household as well as industrial chemicals such as detergents, bleach and acids. General uses of HDPE include injection-molded beverage cases, bread trays as well as films for grocery sacks and bottles for beverages and household chemicals.
Polyvinyl Chloride (PVC) has excellent transparency, chemical resistance, long term stability, good weatherability and stable electrical properties. Vinyl products can be broadly divided into rigid and flexible materials. Rigid applications are concentrated in construction markets, which includes pipe and fittings, siding, rigid flooring and windows. PVC's success in pipe and fittings can be attributed to its resistance to most chemicals, imperviousness to attack by bacteria or micro-organisms, corrosion resistance and strength. Flexible vinyl is used in wire and cable sheathing, insulation, film and sheet, flexible floor coverings, synthetic leather products, coatings, blood bags, and medical tubing.
Low Density Polyethylene (LDPE) is predominantly used in film applications due to its toughness, flexibility and transparency. LDPE has a low melting point making it popular for use in applications where heat sealing is necessary. Typically, LDPE is used to manufacture flexible films such as those used for dry cleaned garment bags and produce bags. LDPE is also used to manufacture some flexible lids and bottles, and it is widely used in wire and cable applications for its stable electrical properties and processing characteristics.
Polypropylene (PP) has excellent chemical resistance and is commonly used in packaging. It has a high melting point, making it ideal for hot fill liquids. Polypropylene is found in everything from flexible and rigid packaging to fibers for fabrics and carpets and large molded parts for automotive and consumer products. Like other plastics, polypropylene has excellent resistance to water and to salt and acid solutions that are destructive to metals. Typical applications include ketchup bottles, yogurt containers, medicine bottles, pancake syrup bottles and automobile battery casings.
Polystyrene (PS) is a versatile plastic that can be rigid or foamed. General purpose polystyrene is clear, hard and brittle. Its clarity allows it to be used when transparency is important, as in medical and food packaging, in laboratory ware, and in certain electronic uses. Expandable Polystyrene (EPS) is commonly extruded into sheet for thermoforming into trays for meats, fish and cheeses and into containers such as egg crates. EPS is also directly formed into cups and tubs for dry foods such as dehydrated soups. Both foamed sheet and molded tubs are used extensively in take-out restaurants for their lightweight, stiffness and excellent thermal insulation.
There are many other plastics beyond the most common ones described above, for example nylon, ABS copolymers, polyurethanes, and polymethyl methacrylate.
Whether you are aware of it or not, plastics play an important part in your life. Plastics' versatility allow them to be used in everything from car parts to doll parts, from soft drink bottles to the refrigerators they are stored in. From the car you drive to work in to the television you watch at home, plastics help make your life easier and better. So how is it that plastics have become so widely used? How did plastics become the material of choice for so many varied applications?
The simple answer is that plastics can provide the things consumers want and need at economical costs. Plastics have the unique capability to be manufactured to meet very specific functional needs for consumers. So maybe there's another question that's relevant: What do I want? Regardless of how you answer this question, plastics can probably satisfy your needs.
If a product is made of plastic, there's a reason. And chances are the reason has everything to do with helping you, the consumer, get what you want: Health. Safety. Performance. and Value. Plastics help make these things possible.
Just consider the changes we've seen in the grocery store in recent years: plastic wrap helps keep meat fresh while protecting it from the poking and prodding fingers of your fellow shoppers; plastic bottles mean you can actually lift an economy-size bottle of juice and should you accidentally drop that bottle, it is shatter-resistant. In each case, plastics help make your life easier, healthier and safer.
Grocery Cart vs. Dent-Resistant Body Panel
Plastics also help you get maximum value from some of the big-ticket items you buy. Plastics help make portable phones and computers that really are portable. They help major appliances - like refrigerators or dishwashers - resist corrosion, last longer and operate more efficiently. Plastic car fenders and body panels resist dings, so you can cruise the grocery store parking lot with confidence.
Modern packaging -- such as heat-sealed plastic pouches and wraps -- helps keep food fresh and free of contamination. That means the resources that went into producing that food aren't wasted. It's the same thing once you get the food home: plastic wraps and resealable containers keep your leftovers protected -- much to the chagrin of kids everywhere. In fact, packaging experts have estimated that each pound of plastic packaging can reduce food waste by up to 1.7 pounds.
Plastics can also help you bring home more product with less packaging. For example, just 2 pounds of plastic can deliver 1,300 ounces -- roughly 10 gallons -- of a beverage such as juice, soda or water. You'd need 3 pounds of aluminum to bring home the same amount of product, 8 pounds of steel or over 40 pounds of glass. Not only do plastic bags require less total energy to produce than paper bags, they conserve fuel in shipping. It takes seven trucks to carry the same number of paper bags as fits in one truckload of plastic bags. Plastics make packaging more efficient, which ultimately conserves resources.
Plastics engineers are always working to do even more with less material. Since 1977, the 2-liter plastic soft drink bottle has gone from weighing 68 grams to just 47 grams today, representing a 31 percent reduction per bottle. That saved more than 180 million pounds of packaging in 2006 for just 2-liter soft drink bottles. The 1-gallon plastic milk jug has undergone a similar reduction, weighing 30 percent less than what it did 20 years ago.
Doing more with less helps conserve resources in another way. It helps save energy. In fact, plastics can play a significant role in energy conservation. Just look at the decision you're asked to make at the grocery store checkout: "Paper or plastic?" Plastic bag manufacture generates less greenhouse gas and uses less fresh water than does paper bag manufacture. Not only do plastic bags require less total production energy to produce than paper bags, they conserve fuel in shipping. It takes seven trucks to carry the same number of paper bags as fits in one truckload of plastic bags.
Plastics in Home Construction
Plastics also help to conserve energy in your home. Vinyl siding and windows help cut energy consumption and lower heating and cooling bills. Furthermore, the U.S. Department of Energy estimates that use of plastic foam insulation in homes and buildings each year could save over 60 million barrels of oil over other kinds of insulation.
The same principles apply in appliances such as refrigerators and air conditioners. Plastic parts and insulation have helped to improve their energy efficiency by 30 to 50 percent since the early 1970s. Again, this energy savings helps reduce your heating and cooling bills. And appliances run more quietly than earlier designs that used other materials.
Recycling of post-consumer plastics packaging began in the early 1980s as a result of state level bottle deposit programs, which produced a consistent supply of returned PETE bottles. With the addition of HDPE milk jug recycling in the late 1980s, plastics recycling has grown steadily but relative to competing packaging materials.
Roughly 60 percent of the U.S. population - about 148 million people - have access to a plastics recycling program. The two common forms of collection are: curbside collection - where consumers place designated plastics in a special bin to be picked up by a public or private hauling company (approximately 8,550 communities participate in curbside recycling) and drop-off centers - where consumers take their recyclables to a centrally located facility (12,000). Most curbside programs collect more than one type of plastic resin; usually both PETE and HDPE. Once collected, the plastics are delivered to a material recovery facility (MRF) or handler for sorting into single resin streams to increase product value. The sorted plastics are then baled to reduce shipping costs to reclaimers.
Reclamation is the next step where the plastics are chopped into flakes, washed to remove contaminants and sold to end users to manufacture new products such as bottles, containers, clothing, carpet, plastic lumber, etc. The number of companies handling and reclaiming post-consumer plastics today is over five times greater than in 1986, growing from 310 companies to 1,677 in 1999. The number of end uses for recycled plastics continues to grow. The federal and state government as well as many major corporations now support market growth through purchasing preference policies.
Early in the 1990s, concern over the perceived reduction of landfill capacity spurred efforts by legislators to mandate the use of recycled materials. Mandates, as a means of expanding markets, can be troubling. Mandates may fail to take health, safety and performance attributes into account. Mandates distort the economic decisions and can lead to sub optimal financial results. Moreover, they are unable to acknowledge the life cycle benefits of alternatives to the environment, such as the efficient use of energy and natural resources.
Pyrolysis involves heating plastics in the absence or near absence of oxygen to break down the long polymer chains into small molecules. Under mild conditions polyolefins can yield a petroleum-like oil. Special conditions can yield monomers such as ethylene and propylene. Some gasification processes yield syngas (mixtures of hydrogen and carbon monoxide are called synthesis gas, or syngas). In contrast to pyrolysis, combustion is an oxidative process that generates heat, carbon dioxide, and water.
Chemical recycling is a special case where condensation polymers such as PET or nylon are chemically reacted to form starting materials.
Source reduction is gaining more attention as an important resource conservation and solid waste management option. Source reduction, often called "waste prevention" is defined as "activities to reduce the amount of material in products and packaging before that material enters the municipal solid waste management system."
Source reduction activities reduce the consumption of resources at the point of generation. In general, source reduction activities include:
Redesigning products or packages so as to reduce the quantity of the materials used, by substituting lighter materials for heavier ones or lengthening the life of products to postpone disposal.
Using packaging that reduces the amount of damage or spoilage to the product.
Reducing amounts of products or packages used through modification of current practices by processors and consumers.
Reusing products or packages already manufactured.
Managing non-product organic wastes (food wastes, yard trimmings) through backyard composting or other on-site alternatives to disposal.
Automotive In automotive design, plastics have contributed to a multitude of innovations in safety, performance and fuel efficiency.
Take safety. Made from durable strands of polyester fiber, seat belts alone have reportedly helped to save 11,000 lives each year, according to the National Highway Traffic Safety Administration (NHTSA). Airbags, commonly made from high-strength nylon fabric, can reduce the risk of dying in a direct, frontal car crash by about 30 percent, according to NHTSA statistics. And child safety seats made possible by numerous advancements in polymer science help to protect our kids at every turn.
Another priority in automotive design is weight reduction, a key driver in boosting fuel efficiency, reducing emissions and lowering costs for motorists. Many plastic components can weigh 50 percent less than similar components made from other materials. That’s one reason why today’s average light vehicle contains 332 pounds of plastics and composites, 8.3 percent by weight.
But, it’s far from the only reason. Fact is, plastics deliver the engineering and styling qualities to go just about anywhere that innovation and high performance are demanded. In exterior applications, from bumper to bumper, plastics are not only light weight, they give designers the freedom to create innovative concepts that in many instances would otherwise be impractical or virtually impossible. Plastics also resist dents, dings, stone chips and corrosion. They allow cost-saving part consolidation and facilitate modular assembly practices for reduced production costs.
As for interiors, plastics have been nothing less than revolutionary. They have proven to be a great material for creating comfortable, durable and aesthetically pleasing interior components, while enhancing occupant protection, reducing noise and vibration levels.
Plastics don’t stop there. In electrical, power train, fuel, chassis and engine applications, they’re proving to be strong, durable, corrosion-resistant and able to withstand high temperatures in harsh engine environments.
Focus on Lightweighting for Improved Fuel Economy
When weight-savings is important, especially for improved fuel economy and lower vehicle emissions, plastics are often considered great materials. Automotive components designed in plastic and plastic-metal hybrids have achieved significant weight savings over some conventional designs. As the use of plastics in vehicle manufacturing increases, lightweighting design techniques — the integration of plastics and polymer composites into vehicle design where some other materials have been traditionally used — can benefit performance and energy savings.
Building & Construction
From residential homes to commercial buildings, and from hospitals to schools, architects and designers rely on plastics to help maximize energy efficiency, durability and performance. In addition to potentially lightening a structure’s environmental footprint, properly installed plastic building products can help reduce energy and maintenance costs over many years.
Energy Savings: Adding It All Up
A one-year study1 found that the use of plastic building and construction materials saved 467.2 trillion Btu of energy over alternative construction materials. That’s enough energy saved over the course of a year to meet the average annual energy needs of 4.6 million U.S. households, or all of the households in 11 states: Nebraska, Utah, Nevada, Maine, Indiana, Hawaii, Montana, South Dakota, North Dakota, Arkansas and Wyoming. Savings vary by material and products. (Source: Franklin Associates, Ltd., U.S. DOE and U.S. Census Bureau).
Following are some examples of plastic building products that promote the efficient use of energy and other resources:
Roofing systems made with spray polyurethane foam (SPF) offer durability, energy savings and moisture control. This foam can be used to cover an existing roof, helping to reduce the amount of building materials sent to landfills.
In walls, the use of structural insulated panels (SIPs) made with expanded polystyrene (EPS) can help homeowners save hundreds of dollars annually on heating and cooling bills. Savings vary by material and products. EPS starts out as a plastic pellet and ends up as nearly 95 percent air, a very effective insulator.
Vinyl is increasingly found in durable, easy-to-clean vinyl wall coverings and requires only half as much energy to manufacture as the same amount of paper wall coverings.
Plastics also rival traditional materials for windows and frames. For example, polycarbonate – a material also used in eyeglasses – is used in windows. These lightweight, shatter-resistant plastic products have low thermal conductivity, which can help to reduce heating and cooling costs.
Vinyl window frames save the U.S. nearly 2 trillion thermal units of energy per year, helping reduce the greenhouse gas emissions associated with energy generation – all the while cutting maintenance time, materials and costs.
Polyolefin, polyvinyl chloride (PVC), and acrylonitrile butadiene styrene (ABS) pipes and fittings, offer excellent fusion integrity for continuous pipeline systems, helping to eliminate potential leak points where water could be wasted.
In residential use, cross-linked polyethylene piping (PEX) is effective in manifold systems—due to its flexibility, lightness, and ease of installation—allowing multiple feed lines throughout a house, which allows hot water to arrive more quickly to a sink or shower. This can significantly save water.
Decks, fences and railings
Lumber made from recycled plastics or plastic-wood composites can outlast traditional materials, often require less maintenance, and are resistant to peeling, cracking, splintering or fading.
Plastic House Wrap
The advent of plastic house wrap technology has reduced the infiltration of outside air into the average home by 10-50%, helping to drastically reduce the energy required to heat or cool the home. These plastic films have helped reduce greenhouse gas emissions in the U.S. by as much as 120 to 600 million tons of CO2 since 1980 (assuming that all homes built since 1980 have some form of plastic barrier).
For homeowners, this means that the energy saved by the use of house wrap can surpass the energy used to make the plastic product in less than two months after installation. The greenhouse gas emissions avoided due to reduced energy use can surpass the emissions released in the manufacture of house wrap in three weeks or less.
For each of the above examples, energy savings can vary. Find out why in the seller’s fact sheet for these plastic building products, which include house wraps, foam insulation, sheathing insulation and sealants. Check to see if your local retailer offers fact sheets on individual building products.
Electrical & Electronics
From computers and cell phones to televisions and microwaves, durable, lightweight and affordable plastics have helped revolutionize the electronics we rely on every day. Plastics deliver an incredible range of performance benefits. Their unique combination of performance properties inspires innovation on two fronts: the development of new and better products and the more efficient use of resources.
Plastics enable many of our favorite electronics to do more with less. For instance, plastics are essential to advances in weight reduction and miniaturization in many electronic products, so less material is used in production. In addition, plastics can be engineered to meet very specific performance requirements, often helping to achieve greater energy efficiency over the course of a product’s life.
For more than a decade, ACC’s Plastics Division has been helping promote sound plastics recycling and recovery from electronic equipment and products. We sponsor research and development projects, publish new information and support technology transfer initiatives. Our knowledge base has grown significantly in recent years, and as the quest for answers continues, we are committed to working with stakeholders throughout the plastics, electronics supply and stakeholder groups to advance the responsible and cost-effective recycling of plastics from electronic equipment and products.
Recycling facilities may not be available in all areas. Check to see if recycling facilities exist in your community.
Packaging & Consumer Products
From the manufacturer to the grocer and to our dinner tables, airtight plastic packaging helps keep foods fresh and free from contamination. In the refrigerator, plastics help to make bottles lighter and shatter-resistant, so it’s safer and easier to lift and serve our favorite beverages. In the medicine cabinet, plastics make possible child-resistant closures for pharmaceuticals. And, when it comes to big-ticket purchases, plastic packaging helps to protect items like appliances and electronics, until they arrive safely in our homes.
But plastics don’t just make packaging more effective; they can also make packaging more efficient, helping to conserve resources. Learn how plastics are enabling us to reduce, reuse, recycle and recover the energy and materials used to create packaging.
ACC Plastics Division Trains Wal-Mart Buyers and Suppliers on Plastics At Wal-Mart’s Sustainable Packaging Fair (April 15-16, 2008), ACC Plastics Division and members provided three one-hour training sessions on plastic packaging sustainability. The first, session titled Plastics 101, was delivered by Keith Christman. The second, on different plastic forms, was led by Charlene Wall of BASF and the third, by Jeff Wooster of Dow Chemical, was on bioplastics. The sessions highlighted how plastics are commonly used to reduce package weight thereby reducing environmental impact. The presentations used both Life Cycle Assessment and Wal-Mart’s packaging scorecard to show how plastic packaging reduces environmental impacts compared to alternatives. Please contact Keith Christman for more information.
Plastics help us to do more with less in many ways. When it comes to packaging, plastics often enable manufacturers to ship more product with less packaging material. This process of light-weighting can play an important role in boosting the environmental and economic efficiency of consumer product packaging. Consider these examples:
Delivering more beverage with less packaging. Just 2 pounds of plastic can deliver 1000 ounces – roughly 8 gallons – of a beverage. Three pounds of aluminum, 8 pounds of steel or 27 pounds of glass would be needed to deliver the same amount.
Making food packaging more efficient. Plastic jars can use up to approximately 90 percent less material by weight than their glass counterparts. Plastic containers also can use about 38 percent less material than similarly sized steel cans. And extremely lightweight, flexible packaging made from plastic or plastic-and-foil composites can use up to 80 percent less material than traditional bag-in-box packages.
Continuously improving through innovation. Plastics are re-engineered to become lighter and more efficient all the time. Today’s 2-liter plastic beverage bottle and 1-gallon milk jug weigh approximately 33 percent less than they did in the 1970s.
Eliminating excess packaging. By replacing the classic fiberboard container, plastic loop carriers can reduce waste by 1.88 ounces per twelve-pack of beverage – or 722 pounds per truckload. And marketers of snack foods, cosmetics and single-serve meals are using colorful shrink film labels to add shelf-appeal right on their containers, eliminating the need for economically and environmentally costly outer boxes.
Reducing transportation energy. Lighter packaging can mean lighter loads or fewer trucks and railcars are needed to ship the same amount of product, helping to reduce transportation energy, decrease emissions and lower shipping costs.
Trimming waste. Weight-reduced packaging also helps to reduce the amount of waste generated or the amount of a material that needs to be recycled after a package is used.
Plastic’s durability makes it a preferred material for reusable items such as storage bins, sealable food containers and refillable sports bottles. In industrial shipping, plastic pallets are impervious to moisture and most chemicals, so they can be used over and over. For commercial produce shipments, plastic produce crates are durable, easy-to-clean, and cost-effective. In addition to conserving raw materials, choosing reusable items, where appropriate, helps to offset trash disposal costs and reduce the amount of waste sent to landfills.
Since the early days of plastics recycling in the 1970s, the nation’s recycling infrastructure has grown significantly1. In fact, the pounds of post-consumer plastic packaging collected and recycled has grown every year since 1990. Today, over 80 percent of U.S. households have access to plastic recycling programs, and in 2005, more than 2.1 billion pounds of plastic bottles were collected for recycling.
Although bottles remain one of the most readily recycled plastics, a growing number of communities are collecting and recycling other rigid plastic containers, such as tubs, trays and lids. And many national grocery and retail chains now invite consumers to return used plastic bags for recycling.
Through these programs, plastics are collected, processed for recycling and used to create second-generation products ranging from fleece jackets and detergent containers to carpeting and composite lumber for outdoor decking.
Another way to conserve resources is to recover the energy value of plastic packaging items after their useful life has ended. Traditional plastics are made from natural gas and, to a lesser extent, petroleum. Although plastics play a role in nearly every facet of our lives, plastics production accounts for only 5 percent of the nation’s annual consumption of natural gas and petroleum. Packaging, the largest market for plastics, accounts only for 1.4 percent.
Because the energy value of plastics is equivalent to fuel oil, plastics are a great source of fuel for waste-to-energy plants. When plastics are processed in modern energy recovery facilities, they help other wastes burn completely, producing cleaner emissions and less ash for disposal. Burning plastic can help supply an abundant amount of energy for electricity, while reducing the cost of municipal waste disposal and conserving landfill space.
Q: How are plastics made?
A: Most commercial plastics encountered by consumers consist of building blocks of carbon. Those building blocks are typically derived from petroleum or natural gas, but can be derived from coal or biological sources. The building blocks of small molecules are called monomers. The monomers used are many and can be combined in various combinations to achieve special properties and characteristics. The nature of the polymer science is such that the monomers must be very pure to make useful plastics. Plastics can be made at very high pressures using gases, in solvents or liquid emulsions, or as melted materials. Each plastic has preferred manufacturing techniques based on its specific chemistry. All successful chemical syntheses are characterized by purification of raw materials, reuse of surplus material, efficient conversion of materials to useful plastic, efficient use of energy, and minimized releases of byproducts to the environment.
Q: Why are plastics used in packaging?
A: Packaging serves many purposes. The public may think the package lasts only a few minutes during the use of the product, but the real demands are much more extensive. Packaging must deliver the product through a potentially long distribution chain to the consumer such that the product meets all expectations regardless of the history encountered. The package must allow the product to be attractive and must deliver aesthetic appeal and information. The package must protect the product at low cost and ease of use with minimal environmental impact. And the package must meet the various regulatory requirements set by various governments. With the proper selection of plastic and packaging type, the quality of the product good, ranging from sensitive electronics to fresh foods, can be maintained during shipping, handling and merchandising. Plastics are a versatile family of materials that are suitable for a wide range of packaging applications. In many cases, plastics offer the best protection while using minimal resources and creating less waste than alternative materials. A study in Germany showed that 400 percent more material by weight would be needed to make packaging if there were no plastics, and the volume of packaging would more than double1. Another European study showed that if plastic packaging did not exist, the annual extra burden required to replace the packaging function would consume an additional 14.2 millions tons of oil (equal to a line of super tanker ships over 14 miles long) and produce an additional 47.3 million tons of CO2 (equal to the annual output of over 12 million automobiles)2. While all packaging continues to be optimized, the basic message of the efficiency of plastic packaging to deliver a product as expected and at low cost is still true.
Q: Why do we need different kinds of plastics?
A: Copper, silver and aluminum are all metals, yet each has unique properties. We do not make a car out of silver or a beer can out of copper because the properties of these metals are not the best choice for final product. Likewise, while plastics are all related, each resin has attributes that make it best suited to a particular application. Plastics make this possible because as a material family they are so versatile.
For instance, six resins account for most of the plastics used in packaging:
PET (polyethylene terephthalate) is a clear, tough polymer with exceptional gas and moisture barrier properties. PET’s ability to contain carbon dioxide (carbonation) makes it ideal for use in carbonated soft drink bottles.
HDPE (high density polyethylene) is used in milk, juice and water containers in order to take advantage of its excellent protective water retention properties. Its chemical resistance properties also make it well suited for items such as containers for household chemicals and detergents. And HDPE is used for the secondary packaging, such as reusable pallets, that helps deliver products safely and efficiently in the product distribution system.
Vinyl (polyvinyl chloride, or PVC) provides excellent clarity, puncture resistance, and cling. As a film, vinyl can breathe just the right amount, making it ideal for packaging fresh meats that require oxygen to ensure a bright red surface while maintaining an acceptable shelf life.
LDPE (low density polyethylene) offers clarity and flexibility. It is used to make bottles that require extra flexibility. To take advantage of its strength and toughness in film form, it is used to produce grocery bags and garbage bags, shrink and stretch film, and coating for milk cartons.
PP (polypropylene) has high tensile strength, making it ideal for use in caps and lids that have to hold tightly on to threaded openings. Because of its high melting point, polypropylene can be hot-filled with products designed to cool in bottles, including ketchup and syrup. It is also used for products that need to be incubated, such as yogurt.
PS (polystyrene), in its crystalline form, is a colorless plastic that can be clear and hard. It can also be foamed to provide exceptional insulation properties. Foamed or expanded polystyrene (EPS) is used for products such as meat trays, egg cartons and coffee cups. EPS is also used for secondary packaging to protect appliances, electronics and other sensitive products during transport.
Q: How do I learn more about plastics use in automotive?
A: There are many sources to learn more about plastics in automotive.
The following professional organizations offer books, conference papers, videos, seminars, and more:
ociety of Plastics Engineers: www.4spe.org
Society of Automotive Engineers:,
Society of Manufacturing Engineers, www.sme.org.
To follow current events in the plastics industry, check out the following publications:
Plastics News: www.plasticsnews.com
Modern Plastics Magazine:
Ward’s Auto World: www.wardsauto.com.
SPE publishes a monthly magazine, Plastics Engineering, and the Society of Automotive Engineers publishes Automotive Engineering International Magazine monthly.
Following the links to our member companies at www.plastics-car.com/s_plasticscar/sec_inner.asp?TRACKID=&CID=456&DID=1372 will also fill you in on the plastics industry.
We also offer periodic seminars at the Automotive Learning Center. Join our mailing list to by completing the form in the left-hand column of this website to keep up to date on the latest seminars and events.
Q: Our company manufactures automotive plastic parts. Can you assist me in marketing our products to your members and other U.S. automotive-related companies?
A: As a trade organization, we cannot promote specific products to our members. Our member companies may, however, be contacted directly through links to their websites on our site at www.plastics-car.com/s_plasticscar/sec_inner.asp?CID=456&DID=1372. You may also want to link to the Plastics News supplier directory at www.plasticsnews.com/subscriber/databook.phtml. A supplier directory can also be found on the Society of the Plastics Industry site at www.spidirectory.com.
The Plastics Division of the American Chemistry Council's European counterpart is PlasticEurope. Their website address is www.plasticseurope.org. We also have a Canadian counterpart, CPIA, Canadian Plastics Industry Association, www.cpia.ca
Why Choose Plastics over Metals? Why Choose Acrylic Sheets, Acetal Copolymer, Acrylic Rods, Acrylic Tubes, Machinable Glass Ceramic, Polycarbonate Film, Polycarbonate Sheet, Polyimide, Nylon, Phenolic, Teflon, Torlon, Turcite, Turcit, Tygon, Ultem, Vespel?
Q: What about CFCs used in plastics?
A: Chlorofluorocarbons (CFC’s) were used in the past to make foamed plastic. In response to concerns about the ozone layer, polystyrene manufacturers voluntarily phased out the use of CFC’s in the late 1980s.
Q: Are toxic compounds used to make plastics and if so, would not the plastics be toxic?
A: Some of the raw materials used to make plastics are rather non-reactive at room temperature and others are highly reactive. For example, one reactive compound, ethylene, is used to make polyethylene. It can also be used to make waxes, such as paraffin wax used for candles and food additives. While not particularly toxic, gaseous ethylene is an asphyxiant, chemically active, and highly flammable. When converted to a plastic, those characteristics are changed. The plastics made from transformed raw materials do not have the same properties as the raw materials. EPA has concluded "there is an exceedingly low probability that potential exposure to high molecular weight water-insoluble polymers, as a class, will result in unreasonable risk or injury to human health or the environment"3. Plastics molecules are very large and do not have the same biological properties as the raw materials used to make them.
Q: Are toxic chemicals included in the plastic products we buy?
A: The simple answer is ‘not intentionally’. The more thorough answer is that toxicity is a complicated subject. Salt, and even water, at too high an intake are toxic to humans. Both are necessary for health and neither is considered toxic. To be a risk, any toxic material must be delivered to sensitive organs in sufficient quantity to create an adverse result. Health risk is not created by mere presence alone.
Plastic products may contain many additives that are included to change appearance, such as colors, or to change performance, such as materials that make stiff plastics more limp and flexible. All additives for food packaging must pass stringent testing to meet FDA requirements for indirect food additives whether the additive actually is ingested or not4. Additives for other than food packaging have other requirements to meet. In general, if an additive becomes identified as problematic, alternatives are found and used. As for the plastic itself, manufacturers recognize it is in their best long-term interest to be sure the plastic as made create negligible risk.
Q: Why are plastics used in durable goods?
A: Manufactured items defined with a useful life of more than three years, including automobiles, appliances, computers, etc., are called durable goods. Manufacturers of durable goods choose plastics for many reasons:
The automotive industry chooses plastic for its durability, corrosion resistance, ease of coloring and finishing, resiliency, cost, energy efficiency, and light weight. Light weight translates directly into improved fuel usage experience and lowered costs to the consumer. Use of plastics in car bodies, along with improvements in coating technology, contribute to automobiles lasting much longer than vehicles did before the widespread use of plastics in fender liners, quarter panels, and other body parts.
Major appliance manufacturers use plastics because of their ease of fabrication, wide range of design potential, and thermal, electrical, and acoustic insulation. Plastics characteristics can significantly reduce production and use energy consumption and greenhouse gas generation. Plastic insulation in refrigerators and freezers helps reduce operations costs to the consumer.
The building and construction industry uses vinyl siding for homes because of its appearance, durability, ease of installation, cost, and energy efficiency.
Plastics can reduce energy consumption for the auto, appliance, and building and construction industries, providing a substantial saving in production costs5.
Q: What is resource conservation and why is it important?
A: Through effective resource conservation, we can minimize our impact on the planet by using the earth's resources wisely. To do this, we must more efficiently manage natural resources and lessen the environmental impact of the products we use, from raw materials to production to distribution and on through ultimate disposal. In other words, you should strive to minimize the energy consumed and wastes generated during production, as well as through the life of a product and on to final disposition.
Q: What can I do to conserve resources?
A: In order to conserve resources, you must know about the resources utilized and the way in which they are consumed. Then decisions can be made based upon facts. Some simple actions include carpooling to work or taking public transportation, turning off lights in empty rooms, selecting the energy saver mode on your dishwasher, turning down thermostats at night during the winter and purchasing items with the most efficient packaging.
Q: How do plastics contribute to effective resource conservation?
A: From production through use to waste management, plastics help conserve resources. Their unique properties and characteristics-light weight, durability, formability-enable manufacturers to minimize the raw materials used, energy consumed and waste generated in the production of goods ranging from automobiles to coffee cups. It's important to think about all those steps in a product's life cycle-not just what happens when a product's useful life is over-to get a true picture of its environmental performance.1,2,3,4
Q: Can plastics actually help save energy?
A: Yes. Only about 4-5 percent of the United States fossil energy consumption from natural gas is actually used to produce all of the plastic carpets and clothing, films, packages, appliances, shapes, building materials, automobiles, gadgets, and toys that we use. This is a small percentage in comparison to energy’s other uses for motor fuel and electricity. In addition, it often takes less energy to convert plastics from an industrially purchased pellets into a finished product compared to the production of similar goods made of other materials. For instance:
For equal carrying capacity, plastic grocery bags require about 70% of energy required to make paper grocery bags1.
Foamed polystyrene containers take 30 percent less total energy to make than required for paperboard containers2.
Polyurethane foam insulation in refrigerators and freezers saves operating cost by providing superior thermal insulation. Without the benefits provided by the plastic insulation, these appliances would use up to 63 percent more energy3.
High density polyethylene requires 10% less energy to deliver the same amount of milk as does paperboard cartons4.
A recent study performed by The Corporation for Comprehensive Analyses, “The Contribution of Plastic Products to Resource Efficiency” illustrated that if alternatives were substituted for plastic products about 26% more energy would be required and about 56% more greenhouse gas (GHG) emissions would result. In other words, plastic products in the marketplace today have enabled energy savings equivalent to 22 million metric tons of crude oil, carried by 190 super crude oil tankers. The GHG emissions saved are equivalent to the total CO2 emissions of the countries of Portugal or Belgium.
Q: What would happen if plastic packaging were replaced with alternatives?
A: Without plastics, a German study showed, the energy used to produce packaging would increase by 110%5. By that study, in 2005 United States manufacturers saved 434 trillion Btu. This is a savings equivalent to 72 million barrels of oil.
Q: How do modern landfills protect the environment?
A: The purpose of solid waste management is to remove wastes from living areas in a way that protects human health and the environment. By sealing in wastes, well-designed and well-managed landfills control odors, vermin attraction, litter, gaseous emissions, and water pollution. A modern landfill, referred to as a ‘Title D” landfill as referenced in the Resource Conservation and Recovery Act (RCRA) must be sited to protect environmentally sensitive areas, designed and constructed and operated to reduce and eliminate effluent leakage, odors and gaseous emissions, litter, and vermin. The landfill must be closed properly and monitored. A Title D landfill for municipal solid waste is a cold, dry, airless storage facility that is not designed for any but incidental biodegradation.
Solid waste management facilities that promote biodegradation include composting and bioreactor landfills. The latter are intended to produce saleable methane. Uncontrolled biodegradation could result in production of leachate that, if leaked, would endanger nearby groundwater supplies, lakes and streams. Title D landfills include heavy-gauge plastic liners, required by the EPA, that help protect the groundwater from contamination1.
Construction and demolition debris, including broken concrete, asphalt, shingles, metals, some plastic, and broken wood, may be placed in a special “C&D” landfill. C&D landfills are for materials that do not produce leachate and do not pose risks to groundwater or attract vermin or generate obnoxious odors.
Q: Can degradable plastics contribute to solid waste management?
A: Because modern landfills are designed, built, and managed to limit degradation, degradable materials of any type are not likely to degrade and reduce the volume of landfill required to hold them. Bacteria and fungi convert carbonaceous material, such as paper and food, to carbon dioxide, methane, and water. Biological degradation is either aerobic, meaning air is required and the gaseous product is primarily carbon dioxide, or anaerobic, meaning air is excluded and the gaseous product is primarily methane. Material placed in Title D landfills have periods of aerobic and anaerobic digestion with the generation of landfill gas that is roughly 50:50 methane can carbon dioxide plus about 1% other gases. If the methane is separated from the rest, that methane can be sold as natural gas.
In 2005 7% of disposed solid waste was yard waste. 19.9 million tons, was composted. In addition, 0.4 million tons of food waste was composted. In total, 8.4% of US municipal solid waste was composted in 20052. This does not include backyard composting. In areas where composting is a municipal solid waste disposal option and water is available to promote degradation, compostable plastics can effectively be included in the compostable material. Such compostable material includes wastewater biosolids, manure, yard trimmings, and food waste.
Biodegradable plastics that meet ASTM D6400-99 (American Society for Testing and Materials) (or European Standardization Committee (CEN) EN13432 or International Standards Organization (ISO) ISO 14855) provisions for compostability are considered “compostable plastics”. This means the plastic will rapidly disintegrate in standard industrial composting facilities to compost indistinguishable from compost from other sources at normal processing schedules. Municipal solid waste composting facilities for foodstuffs require special conditions of temperature and humidity not achieved in backyard compost piles. Compostable plastics require the more rigorous conditions of the municipal composting facilities to degrade. It is important to note that not all plastics derived from plant sources are compostable. In the United States, be sure to look for ASTM certification by the Biodegradable Products Institute http://www.bpiworld.org/ .
Flushable, biodegradable diapers and personal hygiene products are readily treated in a regulated wastewater and sewage treatment facility, reducing the impact on other disposal systems.
Degradable or compostable plastics can make a positive contribution to solid waste management. Compostable yard waste bags enhance the value of composted trimmings. Compostable dinnerware allow for efficient composting of restaurant food and cutlery waste. But, degradable plastics do not excuse littering. The degradable plastics generally require intentional solid waste composting facilities to disintegrate. Degradable plastics left on the ground or dropped into waterways and oceans do not “disappear” and do not excuse poor behavior. Degradable plastics are also an issue for recycling of recyclable plastics. Recycled plastics are expected to perform without degraded properties in their subsequent lives. If degradable plastics are mistakenly placed into the recycling stream, the recycled plastics no longer are assured of high quality performance. Once again, proper human behavior can prevent problems. Similarly, recyclable plastics should not be placed with compostable plastics.
Q: Are we running out of safe places to put landfills?
A: In the 1980s, there was a perceived crisis over a lack of landfill space that led to the presumption that America would soon run out of room for its garbage. Images of garbage barges floating up and down our coasts were ingrained into our minds. Even today there are those who believe that America still has a waste "crisis." Yet, the threat of running out of landfill space simply does not exist, and never did. While it is true that there were some localized landfill shortages in the 1980s, particularly in densely populated areas, a shortage never occurred nationwide. While the total number of landfills has decreased over the years, total landfill capacity has increased3 due to construction of larger landfills. Three cartage companies, Waste Management, Allied Waste, and Republic Services collect more than half the nation's trash. According to the New York Times, rather than running out of landfill space, they have sufficient capacity to operate for decades assuming no further expansion of existing sites, no additional sites and no benefit from improved technology. James Thompson with Chartwell Information, publishers of Solid Waste Digest, said the nation has 6.561 billion tons of landfill capacity4. At current rates, this equals 49 years of capacity.
According to a 2005 U.S. EPA report, “Municipal Solid Waste in the United States, 2005 Facts and Figures”, waste disposal has actually declined since 1990. This can be attributed again to the renewed emphasis placed on curbside recycling, the addition of compost programs into communities and the pursuit of source reduction. Between 1990 and 2005, these efforts were responsible for a decrease in waste landfilled, from 142 million tons in 1990 to 133 million tons in 2005. The tonnage landfilled in 2005, 133 million tons, was actually less than landfilled in 1980, 134 million tons. At the same time, the population increased from 227 million in 1980 to 296 million persons in 2005. National recovery levels reached 32.1 percent in 2005 and municipal solid waste landfilled declined from 88.6 percent of all MSW in 1980 to 54.3 percent in 2005.
Environmentally compatible long-term landfilling will continue to evolve with scientific research, technology development, and improved construction and operation. With these safeguards in place, the disposal of plastics will continue to be problem-free.
Waste to energy
Q: What happens inside a modern waste-to-energy facility?
A: The energy value of MSW can be recovered through waste-to-energy (WTE) incineration. Modern energy recovery facilities burn MSW in special combustion chambers, then use the resulting heat energy to generate steam or electricity. This process reduces the volume of MSW to be landfilled by as much as 90 percent. In 1997, there were 112 energy recovery facilities operating in 31 states throughout the United States with a designed capacity of nearly 101,500 tons per day.
Energy recovery facilities are designed to achieve high combustion temperatures that help MSW burn cleaner and create less ash for disposal. Modern air pollution control devices -- wet or dry scrubbers along with electrostatic precipitators or fabric filters -- are used to control and reduce potentially harmful particulates and gases from incinerator emissions.1,2
Q: Are plastics safe in waste-to-energy incineration?
A: Yes. Experts agree that properly equipped, operated and maintained facilities can meet the latest U.S. standards for air pollution control, among the toughest standards in the world. Plastics are a safe and valuable feedstock for these facilities.
Although some activists have suggested there is a link between certain plastics and increased dioxin emissions from w-t-e facilities, a blue-ribbon panel convened by the U.S. Conference of Mayors in 1989 found no evidence to support this claim. A 1995 report from the American Society of Mechanical Engineers reached the same conclusion.2,3,4,5
Q: How do plastics contribute to waste-to-energy incineration?
A: Plastics are typically derived from petroleum or natural gas giving them a stored energy value higher than any other material commonly found in the waste stream. In fact, plastics commonly used in packaging can generate twice as much energy as Wyoming coal and almost as much energy as fuel oil (see chart below). When plastics are processed in modern WTE facilities, they can help other wastes combust more completely, leaving less ash for disposal.
Q: What is recovery?
A: Recovery is the process of obtaining materials or energy resources from solid waste. Recovery includes solid waste management options other than landfilling. Recovered plastics might be recycled into new products. Suitable recovered plastics might be composted. Recovered plastics could be converted to energy in waste-to-energy facilities or used to make process engineered fuels, combinations of collected plastics and paper processed into fuel pellets and the pellets used in conjunction with coal and other fuels in industrial boilers.
Q: How much plastic is recycled?
A: The quantity of post-consumer plastics recycled has increased every year since at least 1990. In 2006 the amount of plastic bottles recycled reached a record high of 2,220,000,000 pounds1.
The amount of PET bottles recycled in 2006 increased more than 102 million pounds compared to 2005.1
HDPE bottle recycling increased in 2005 to 928 million pounds.1
All plastic bottles were recycled at a rate of 24 percent in 2005.1
Q: How does plastics’ recycling work?
A: Successful recovery of plastics requires an infrastructure that can get used plastics from the consumer, process the material to valuable items of commerce, and profitably use the materials in new products. The plastics recycling infrastructure has four parts:
Rather than being discarded, plastics bottles (primarily PET and HDPE) and distribution stretch films (primarily LLDPE) are collected for recycling. Plastic bottles collection methods include curbside collection with other materials and drop-off at recycling centers and redemption centers. When the critical minimum amount of clean material can be isolated, commercial opportunities to sell truckloads of used materials begin.
Plastics from collection programs are sorted to increase their value and compacted to reduce shipping costs. To minimize transportation costs, full trailer loads, at least 30,000 pounds, of baled material are needed.
In conventional mechanical recycling, sorted plastics are chopped, washed and converted into flakes or pellets that are then processed into new products. Chemical recycling technologies process plastics back to their original building blocks (monomers or petroleum feedstocks). These can then be recycled into a number of different products, including new plastics. Either technology is successful. The economics for the two technologies differ with mechanical recycling requiring less investment and successful operation at smaller scale. Some mechanical recycling operations use unwashed plastic.
Reclaimed plastic pellets, films, or flakes are used to manufacture new products. Chemically converted plastics can become petroleum raw materials for making new plastics and other chemicals or fuel.
Q: How many communities collect plastics for recycling?
A: The US EPA states, “By 2005, almost 9,000 curbside programs had sprouted up across the nation. As of 2005, about 500 materials recovery facilities had been established to process the collected materials2”. Following an extensive nationwide survey in 1997, the American Plastics Council (APC) estimated that roughly one-half of all U.S. communities, more than 20,000, are collecting plastics for recycling, primarily PET and HDPE3. Approximately 12,000 communities collect plastics through drop-off centers. In addition, thousands of grocery stores in the United States accept plastic bags for recycling into new trash can liners and other products.
Q: Can some plastics from durable goods be recycled?
A: Yes. A primary challenge is collecting post-consumer plastics from durable goods in quantities of sufficient quality that make recycling cost-effective.
The Vehicle Recycling Partnership (VRP), a consortium formed by General Motors Company, Ford Motor Corporation, and DaimlerChrysler Corporation, opened a joint research center called the Vehicle Recycling Development Center (VRDC) in conjunction with Argonne National Laboratory to develop automotive recycling technology. In 2006 the VRP was in its third year of its third Cooperative Research and Development Agreement (CRADA) with Argonne Labs. The VRP has a collaborative agreement to develop technology to recover and recycle plastics from scrapped vehicles’ bumpers, instrument panels, seats and interior trim. Today, more than 95 percent of all vehicles in the United States go through a market-driven recycling infrastructure, with no added cost or tax to consumers. More than 75 percent, by weight, of each end-of-life vehicle (ELV) is recycled. The CRADA team is working to raise that percentage to as close to 100 percent as conceivably possible4.
In the 1990’s MBA Polymers, Richmond, CA, with support from the American Plastics Council (now the Plastics Division of the American Chemistry Council) developed processes to recycle appliances, computer and business equipment, automobiles, and sporting equipment. These include technology for plastics identification, sorting, improving the quality, and reducing the costs of recycled plastics from durable goods.
Research continues to evaluate recovery of telephones, more automotive parts, computer housings, refrigerator doors and cabinet liners.
Q: How many plastics recyclers are there?
A: The definition of “recycler” can mean a company that collects materials, a company that sorts collected material, a company that mechanically cleans sorted collected materials, a company that processes mixed collected materials, and a company that upgrades cleaned sorted materials. The Plastic Division’s 2007 markets update identified 1,334 businesses that handle and/or reclaim (sort, process and/or produce) post-consumer plastics domestically, and 203 businesses that broker plastics for export. Information about these businesses has been compiled into a special handlers/reclaimers database.
Q: Why is sorting so important in plastics recycling?
A: Plastics are a family of materials. There are different types of plastics, just as there are different types of metal, paper and glass. Even though they are both metals, steel and aluminum have to be separated before recycling, different colors of glass must be sorted and white office paper must be separated from newspapers and paperboard boxes. Each of the six common packaging plastics has performance characteristics that make it best suited for specific applications. Purchasers of recycled resins want to be sure that these properties are retained, so handlers sort plastics by resin type to command the highest market value. Occasionally, innovators have proposed technologies to use mixed, unsorted plastics. Some ventures have succeeded. Overall, however, sorted plastics allow for the highest valued applications for recycled plastics.
Q: What can I recycle?
A: Solid waste management, including recycling, is almost always a local activity with each jurisdiction acting independently of others. Thus, what you can recycle depends on where you live, what your individual community collects. This is determined by what market your community sells materials to. To find out what plastics recycling opportunities are available in your area, check with your county, city, or town department of public works, look under “Recycling” in the Yellow pages, or contact your local trash and solid waste hauler. The most common plastic items collected at the curbside are PET and HDPE bottles. Collecting “all bottles” is actually an efficient means of capturing the many different PET and HDPE bottles and a growing number of communities collect all bottles. Limited markets do exist for PP and PVC bottles. Some communities also collect rigid containers as well. Not all types of plastics products are generally recycled, and recycling facilities may not be available in some areas. So, please check on what is being collected in your locality.
Q: What kinds of products are made with recycled plastics?
A: The variety of products made with recycled plastics is growing. Here are just a few examples:
Recycled PET can be used in producing new food and beverage bottles, deli trays, carpets, clothing, textiles, automobile parts, and strapping for bricks and lumber.
Recycled HDPE can become new bottles for laundry products and motor oil, recycling bins, agricultural pipe, bags, garden edging, decking and plastic lumber.
Recycled vinyl can become playground equipment, flooring tiles, film, and air bubble cushioning.
Recycled LDPE can be used to manufacture bags, compost bins, and plastic lumber.
Recycled PP can be used in automobile parts including battery casings, textiles, industrial fibers, and films used for bulk packaging.
Recycled PS can be used in products including office accessories, garden nursery supplies, and protective package cushioning.
To help public and private sector buyers identify products made with recycled plastic, the Plastics Division of the American Chemistry Council lists “The Recycled Plastic Products Directory” online that lists more than 1,600 products.
Q: Can plastic be recycled back into food contact applications?
A: Today, some recycled plastics are used in food and beverage containers. Recycled PET is used in soft drink containers5. The United States Food and Drug Administration has issued 94 opinion letters that state the Administration has no objection to specific uses of various recycled plastics in food packaging6. Various economic barriers limit widespread use of recycled plastic packaging in direct contact with food.
Q: What are advanced recycling technologies?
A: The term advanced recycling describes a family of plastics recycling processes that yield a variety of versatile small chemical products. Sometimes the term ‘feedstock recycling’ or ‘chemical recycling’ is used. These small chemical products can be the building blocks from which plastics are made. By unlinking or unzipping plastics (polymers) to their original molecular components, recyclers can produce monomers or a petroleum product that can be made into monomers (the basic units from which plastics are made) or a number of other petroleum-based products including synthesis gas. These processes produce products that are identical to virgin feedstocks and monomers used to produce new plastics. Advanced recycling technologies are practiced in circumstances when the supply of proper used plastic material, the total economic structure, and the demand for the product all are as needed.
Q: What resources are available to help increase sustainable recycling?
A: Through organizations such as the Plastics Division of the American Chemistry Council, the plastics industry continues to develop technologies to collect, sort and reclaim plastics more economically. The Plastics Division also focuses on durable products and commercial streams, researching new applications and end-markets for recycled plastics, and promoting existing markets through publications such as “The Recycled Plastic Products Directory. The Plastics Division offers the following services and resources:
Technical Research Programs -- The state of the art in plastics recycling is constantly evolving. The Plastics Division works to hasten this evolution, pursuing a wide range of technical solutions that can add greater automation and operating efficiency to each step of the plastics recycling infrastructure, from collection to end-markets. The findings from these research programs have resulted in a series of technical manuals to help advance plastics recycling across the country.
How to Collect All Plastic Bottles for Recycling – Research sponsored by the American Plastics Council, now the Plastics Division of the American Chemistry council, shows that when curbside collection programs collect all plastic bottles, the quantity of HDPE and PET bottles collected increases while the amount of plastic contamination does not. HDPE and PET bottles total 95% of all bottles used in the United States7. By concentrating on the collection of just bottles, incompatible other plastic items tend not to be included and the quality of the bottle recycling stream improves. Visit the all bottles web site at www.allplasticbottles.org/.
Sorting Plastic Bottles for Recycling
A companion to “How to Collect All Plastic Bottles for Recycling.” This guide assists Materials Recovery Facility (MRF) operators in improving the efficiency of sorting and recovering plastic containers collected from the residential and commercial recyclables streams.
Plastics Recycling in Your Schools
Plastic bottles are lightweight, shatter-proof and re-sealable, and in many instances are the preferred packaging for beverages consumed in our schools. In many instances plastic bottles may be collected for recycling through community programs or through a school’s recycling collector. Other plastic items found in schools may have recycling markets by will require individualized collection strategies. This guide will help you identify and capitalize on plastics recycling opportunities in your school and your locality.
Plastic Film and Bag Recycling
ACC’s Plastic Division recycling efforts focus on bringing awareness of plastic bag recycling to consumers by providing technical assistance in setting up plastic bag recycling programs at municipal drop-offs, working with retailers/grocers to implement new programs, or providing better signage, and helping businesses recycle polyethylene stretch film through the web resource www.plasticbagrecycling.org/.
Q: What is in our waste stream?
A: The Garbage Project, a Department of Applied Research in Anthropology at the University of Arizona, gives an estimated breakdown of the materials disposed of in landfills by volume in the first pie chart. In the second and third charts, the U.S. Environmental Protection Agency (EPA) gives the breakdown of materials and products generated in municipal solid waste (MSW) by weight.
Q: How do plastics contribute to waste reduction?
A: Plastics are strong yet lightweight, meaning it often requires less plastic to make a certain package compared to other possible materials:
The plastic film wrappers now used for large diaper packs create 50 percent less waste by volume than previous packages.
Over 4 million students a day in the U.S. drink their milk or juice in flexible drink pouches. Compared to traditional cartons, the source-reduced pouch reduces weight by 80 percent and volume of waste by 70 percent, which reduces storage and trash disposal costs for schools.1
Plastic grocery bags are lighter and create up to 80 percent less waste by volume than paper sacks.
Normal economic market forces cause manufacturers to continually look for ways to reduce the cost of their packages by minimizing the amount of material used:
An average polystyrene foam plate today requires 25 percent less polystyrene to produce than it did in 1974.2
Plastic grocery sacks were 2.3 mils (thousands of an inch) thick in 1976 and were down to 1.75 mils by 1984. In 1989, new technology gave us the same strength and durability in a bag only 0.7 mil thick.
Along with weight and size reductions, plastics can contribute to waste reduction in other ways:
Plastics have an increased life span. Their physical properties allow them to be used in multiple applications, while their durability and flexibility allow them to be used again and again. For example, some laundry products are being packaged in reusable plastic bottles. Small packages of concentrated product are used to refill the original bottles, helping to reduce total packaging waste.
Plastics are lighter than many alternative materials. They have consistently reduced the weight of truck payloads and allowed companies to ship more product in fewer trucks. More than 2.8 million plastic grocery bags can be delivered in one truck. The same truck can hold only 500,000 paper grocery bags.3
Plastics generally exhibit superior resistance to breakage and denting. This results in fewer container breaches and less product loss on the packaging line, and safer handling in the the home.4
Manufacturers of durable goods choose plastics for many reasons:
Plastics allow highly efficient manufacturing processes (up to 99 percent efficiency) that increase productivity by 20 to 30 percent and reduce capital expenditures by as much as 50 percent.5
Without plastics' resistance to corrosion, the product life of some major appliances would be reduced by nearly 40 percent. By helping them last longer, plastics keep appliances and other durable goods out of the waste stream.5
Q: Are Americans really reducing waste?
A: Yes. According to the EPA, the amount of waste Americans generate (prior to recycling and combustion efforts) has been steadily decreasing. In fact, plastic packaging -- which has undergone substantial source reduction efforts -- accounted for 3.9 percent of all waste generated in 1996, versus 5.5 percent in 1995. These numbers suggest that source reduction is succeeding. Because Americans are generating less waste, the amount going into landfills is decreasing -- 11 6 million tons in 1996 compared to 140 million tons in 1990.6
Q: Can some plastics be used more than once before disposal?
A: Yes. One of plastic's most unique properties is its durability. This durability makes it one of the materials of choice for commonly reused items such as food storage containers and refillable sports bottles. Reuse of plastics also helps offset trash disposal costs and reduces the amount of waste sent to landfills. For example:
More than 200 schools in seven states and Ontario, Canada, use refillable plastic milk bottles that can be washed, refilled and reused over 100 times before being recycled.7
As much as 40 percent of selected plastic parts from damaged or discarded cars are repaired and reused, reducing the amount of automotive components sent to l andfills.8
More More than 1,400 quality products made with or packaged in post-consumer recycled plastics are now commercially available, including single-use cameras, park benches, sweaters, jeans, videocassettes, detergent bottles and children's toys.
Acrylic Properties Of Sheets (The Value Of Plastic Products)
Polymethylmethacrylate - Acrylic - PMMA What is Acrylic?
What is an acrylic sheet?
Have you ever looked at something made of plastic and wondered how it was made?
Are you aware that Jet-aircraft cabin windows are made from acrylic sheet?
Itâ€™s obviously not a metal, wood or plant based derivative. To the educated person, it could be assumed that itâ€™s made by a chemical process, but not much more about it is as easily surmised. Clearly, acrylic thermoplastics have some very interesting characteristics and properties. Of course, they are well known for their crystal clarity and outstanding weatherability. But did you also know they are available in cast sheet, rod, and tube, extruded sheet and film, and compounds for injection molding and extrusion? Acrylic can be used to manufacture brochure holders, racks, counter displays, boxes and point of purchase displays, plates, Tumblers, Tables, shower doors, bath enclosures, windows, Acrylic PC Cases, Acrylic Fish aquariums, Burets, trays, racks, among other products.
Below are some general properties of acrylic sheet:
Strong and resists weathering
Flexible when compared with glass
Less breakable than glass
Can withstand sunlight for long durations
Resistant to most chemicals and industrial fumes
Can transmit or filter ultraviolet light
Can be cleaned easily
Can be cut by various methods
Other general properties include the ability to transmit and control light. They are also stable against discoloration, and have superior dimensional stability, as you would notice if you have an acrylic brochure display, counter display, donation / suggestion box or point of purchase (p.o.p) display. Possessing an excellent combination of structural and thermal properties, clear acrylic plastic is as transparent as the finest optical glass:
Possess a light transmittance of 92%
Low haze level of approximately 1%
Index of refraction of 1.49
It also has the ability to be injected with color, producing a full spectrum of transparent, translucent, or opaque colors depending on your needs. This process does no harm in terms of long-term durability; colored acrylics can be used outdoors for a long time. Why? They are formulated to filter ultraviolet energy in the 360-nm and lower band. Other acrylic formulations are opaque to UV light or provide reduced UV transmission.
And how about mechanical properties? Although not known for having many, acrylics can be used for short-term loading. If the intended use is long-term, stresses must be limited to 1,500 psi to avoid surface cracking and deterioration.
Acrylic does well in the cold, as the impact resistance of standard formulations is maintained in these conditions. It should be noted that high-impact acrylic grades have greater impact strength than standard grades at room temperature, but impact strength decreases as temperature drops. Some types of acrylic are even known to resist bullets!
Acrylic plastics are highly scratch resistant, especially among other thermoplastics. Itâ€™s a good idea, however, to ensure proper maintenance and cleaning. Keep in mind that abrasion-resistant acrylic sheet is available and has the same optical and impact properties as standard grades. You will see this in many of our brochure displays, racks, counter displays, donation / suggestion boxes and point of purchase (p.o.p) displays.
This brings up a good point â€“ its versatility and adaptability. Are you aware that Jet-aircraft cabin windows are made from acrylic sheet? They do this by inducing molecular orientation during forming. This proves the potential strength of acrylic sheet. How do they react to other chemicals and compounds? Acrylic sheet and moldings resist solutions of inorganic acids and alkalies and aliphatic hydrocarbons such as VM&P naphtha, as well as most detergent solutions and cleaning agents. They are attacked by chlorinated and aromatic hydrocarbons, esters, and ketones.
What is Acrylic?
Acrylic is a useful, clear plastic that resembles glass, but has properties that make it superior to glass in many ways. Common brands of high-grade acrylic include Polycast, Lucite and Plexiglass.
There are two basic types of acrylic: extruded and cell cast. Extruded or "continuous cast" acrylic is made by a less expensive process, is softer, can scratch easier and may contain impurities. Cell cast acrylic is a higher quality acrylic.
Acrylic is used to make various products, such as shower doors, bath enclosures, windows and skylights. It is chosen over glass for many reasons. It is many times stronger than glass, making it much more impact resistant and therefore safer. Falling against an acrylic shower door will not likely break it. Baseballs that crash through glass windows will, in most cases, bounce off acrylic windows. Acrylic also insulates better than glass, potentially saving on heating bills.
Another great advantage of acrylic is that it is only half as heavy as glass. This makes working with acrylic much easier. It can also be sawed, whereas glass must be scored.
Adding to this favorable array of properties, a transparency rate of 93% makes acrylic the clearest material known. Very thick glass will have a green tint, while acrylic remains clear.
A unique property of plastic is its ability to be shaped. Bow-front aquariums are beautiful examples of acrylic's wonderful properties. There are also no seams in acrylic structures, as chemical welding at the molecular level actually "melts" seams into one piece of solid material. Seams that are welded and polished are invisible.
There are some misconceptions about acrylic, namely that it yellows, turns brittle and cracks over time. Though this might be true of very cheap forms of plastic, it is not so with acrylic. For example, the fighter planes of WWII have acrylic bubble-tops. Airplane windows are also acrylic. If taken care of, acrylic remains new looking regardless of age or exposure to sun.
For all of its advantages, there are two disadvantages of acrylic: it is more expensive than glass, and if exposed to a direct flame it will melt and eventually burn.
Today acrylic is used more than ever. Virtually all major public aquariums now build display tanks out of acrylic. You will also find acrylic in malls, institutions, prisons, hospitals and commercial buildings. Acrylic just over one inch thick (32mm) is bullet resistant. The Presidential motorcade, the Pope's booth-vehicle, teller enclosures and drive-through window enclosures all feature bullet-resistant acrylic.
If upgrading the windows in your house, remodeling your bathroom, or adding a beautiful aquarium, consider acrylic. It may cost a little more than glass, but its sheer clarity, light weight and insulating properties make it a superior choice for many applications.
What is Polycarbonate?
Polycarbonate is a versatile, tough plastic used for a variety of applications, from bulletproof windows to compact disks (CDs). The main advantage of polycarbonate over other types of plastic is unbeatable strength combined with light weight. While acrylic is 17% stronger than glass, polycarbonate is nearly unbreakable. Bulletproof windows and enclosures as seen inside banks or at drive-throughs are often made of polycarbonate. Add to this the advantage that polycarbonate is just one-third the weight of acrylic, or one-sixth as heavy as glass, and the only drawback is that it is more expensive than either acrylic or glass.
Compact disks and digital versatile discs (DVDs) are perhaps the most readily recognized examples of polycarbonate. If youâ€™ve ever archived files on a writable CD, then later tried to break it before throwing it away, you know just how tough polycarbonate can be!
Clear polycarbonate is used to make eyeglasses because of its excellent transparency, durability, and high infraction index. This means that it bends light to a far greater degree than glass or other plastics of equal thickness. Since prescription lenses bend light to correct vision, polycarbonate lenses can be far thinner than glass or conventional plastic, making polycarbonate the ideal material for heavy prescriptions. Thin polycarbonate lenses correct poor vision beautifully without distorting the face or the size of the eyes, yet this extremely thin lens is virtual indestructible, an important safety factor for children and active adults.
Polycarbonate lenses are also used in quality sunglasses that incorporate filters to block ultra-violet (UV) rays and near-UV rays. The lenses can also be polarized to block glare, and their high impact resistance makes them perfect for sports. Many sunglasses manufacturers choose polycarbonate because it can be easily shaped without problems like cracking or splitting, resulting in extremely lightweight, distortion-free, fashionable glasses that feature all of the health benefits doctors recommend.
Polycarbonate is also used in the electronics industry. Appleâ€™s original iMac featured polycarbonate mixed with clear colors for a transparent computer case. Many cell phones, pagers, and laptops also use clear or opaque polycarbonate in their casings.
Other uses for polycarbonate include greenhouse enclosures, automobile headlights, outdoor fixtures, and medical industry applications, though the list is virtually endless. Somewhat less toxic than polyvinyl chloride (PVC) to produce, polycarbonate nevertheless requires toxic chemicals in its production phase. It is, however, recyclable and environmentally preferable to PVC in applications for which either material can be used.
Acrylic plastic refers to a family of synthetic, or man-made, plastic materials containing one or more derivatives of acrylic acid. The most common acrylic plastic is polymethyl methacrylate (PMMA), which is sold under the brand names of Plexiglas, Lucite, Perspex, and Crystallite. PMMA is a tough, highly transparent material with excellent resistance to ultraviolet radiation and weathering. It can be colored, molded, cut, drilled, and formed. These properties make it ideal for many applications including airplane windshields, skylights, automobile taillights, and outdoor signs. One notable application is the ceiling of the Houston Astrodome which is composed of hundreds of double-insulating panels of PMMA acrylic plastic.
A polymer, therefore, is a material made up of many molecules, or parts, linked together like a chain. Polymers may have hundreds, or even thousands, of molecules linked together. More importantly, a polymer is a material that has properties entirely different than its component parts. The process of making a polymer, known as polymerization, has been likened to shoveling scrap glass, copper, and other materials into a box, shaking the box, and coming back in an hour to find a working color television set. The glass, copper, and other component parts are still there, but they have been reassembled into something that looks and functions entirely differently.
The first plastic polymer, celluloid, a combination of cellulose nitrate and camphor, was developed in 1869. It was based on the natural polymer cellulose, which is present in plants. Celluloid was used to make many items including photographic film, combs, and men's shirt collars.
In 1909, Bakelite plastic was used in radio, telephone, and electrical equipment, as well as counter tops, buttons, and knife handles.
Acrylic acid was first prepared in 1843. Methacrylic acid, which is a derivative of acrylic acid, was formulated in 1865. When methacrylic acid is reacted with methyl alcohol, it results in an ester known as methyl methacrylate. The polymerization process to turn methyl methacrylate into polymethyl methacrylate was discovered in 1877, but it wasn't until 1936 that the process was used to produce sheets of acrylic safety glass commercially. During World War II, acrylic glass was used for periscope ports on submarines and for windshields, canopies, and gun turrets on airplanes.
Methyl methacrylate is the basic molecule, or monomer, from which polymethyl methacrylate and many other acrylic plastic polymers are formed. The chemical notation for this material is CH2=C(CH3) COOCH3. It is written in this format, rather than the more common chemical notation C5H8O2, to show the double bond (=) between the two carbon atoms in the middle. During polymerization, one leg of this double bond breaks and links up with the middle carbon atom of another methyl methacrylate molecule to start a chain. This process repeats itself until the final polymer is formed.
Methyl methacrylate may be formed in several ways. One common way is to react acetone [CH3COCH3] with sodium cyanide [NaCN] to produce acetone cyanhydrin [(CH3)2C(OH)CN]. This in turn is reacted with methyl alcohol [CH3OH] to produce methyl methacrylate.
Other similar monomers such as methyl acrylate [CH2=CHCOOCH,] and acrylonitrile [CH2=CHCN] can be joined with methyl methacrylate to form different acrylic plastics. When two or more monomers are joined together, the result is known as a copolymer. Just as with methyl methacrylate, both of these monomers have a double bond on the middle carbon atoms that splits during polymerization to link with the carbon atoms of other molecules. Controlling the proportion of these other monomers produces changes in elasticity and other properties in the resulting plastic.
The Manufacturing Process
Acrylic plastic polymers are formed by reacting a monomer, such as methyl methacrylate, with a catalyst. A typical catalyst would be an organic peroxide. The catalyst starts the reaction and enters into it to keep it going, but does not become part of the resulting polymer.
Acrylic plastics are available in three forms: flat sheets, elongated shapes (rods and tubes), and molding powder. Molding powders are sometimes made by a process known as suspension polymerization in which the reaction takes place between tiny droplets of the monomer suspended in a solution of water and catalyst. This results in grains of polymer with tightly controlled molecular weight suitable for molding or extrusion.
Acrylic plastic sheets are formed by a process known as bulk polymerization. In this process, the monomer and catalyst are poured into a mold where the reaction takes place. Two methods of bulk polymerization may be used: batch cell or continuous. Batch cell is the most common because it is simple and is easily adapted for making acrylic sheets in thicknesses from 0.06 to 6.0 inches (0.16-15 cm) and widths from 3 feet (0.9 m) up to several hundred feet. The batch cell method may also be used to form rods and tubes. The continuous method is quicker and involves less labor. It is used to make sheets of thinner thicknesses and smaller widths than those produced by the batch cell method.
We will describe both the batch cell and continuous bulk polymerization processes typically used to produce transparent polymethyl methacrylic (PMMA) sheets.
Batch cell bulk polymerization
1. The mold for producing sheets is assembled from two plates of polished glass separated by a flexible "window-frame" spacer. The spacer sits along the outer perimeter of the surface of the glass plates and forms a sealed cavity between the plates. The fact that the spacer is flexible allows the mold cavity to shrink during the polymerization process to compensate for the volume contraction of the material as the reaction goes from individual molecules to linked polymers. In some production applications, polished metal plates are used instead of glass. Several plates may be stacked on top of each other with the upper surface of one plate becoming the bottom surface of the next higher mold cavity. The plates and spacers are clamped together with spring clamps.
2. An open comer of each mold cavity is filled with a pre-measured liquid syrup of methyl methacrylate monomer and catalyst. In some cases, a methyl methacrylate prepolymer is also added. A prepolymer is a material with partially formed polymer chains used to further help the polymerization process. The liquid syrup flows throughout the mold cavity to fill it.
3. The mold is then sealed and heat may be applied to help the catalyst start the reaction.
4. As the reaction proceeds, it may generate significant heat by itself. This heat is fanned off in air ovens or by placing the molds in a water bath. A programmed temperature cycle is followed to ensure proper cure time without additional vaporization of the monomer solution. This also prevents bubbles from forming. Thinner sheets may cure in 10 to 12 hours, but thicker sheets may require several days.
5. When the plastic is cured, the molds are cooled and opened. The glass or metal plates are cleaned and reassembled for the next batch.
6. The plastic sheets are either used as is or are annealed by heating them to 284-302Â°F (140-150Â°C) for several hours to reduce any residual stresses in the material that might cause warping or other dimensional instabilities.
7. Any excess material, or flash, is trimmed off the edges, and masking paper or plastic film is applied to the surface of the finished sheets for protection during handling and shipping. The paper or film is often marked with the material's brand name, size, and handling instructions. Conformance with applicable safety or building code standards is also noted.
Continuous bulk polymerization
1. The continuous process is similar to the batch cell process, but because the sheets are thinner and smaller, the process times are much shorter. The syrup of monomer and catalyst is introduced at one end of a set of horizontal stainless steel belts running parallel, one above the other. The distance between the belts determines the thickness of the sheet to be formed.
2. The belts hold the reacting monomer and catalyst syrup between them and move it through a series of heating and cooling zones according to a programmed temperature cycle to cure the material.
3. Electric heaters or hot air may then anneal the material as it comes out of the end of the belts.
4. The sheets are cut to size and masking paper or plastic film is applied.
The storage, handling, and processing of the chemicals that make acrylic plastics are done under controlled environmental conditions to prevent contamination of the material or unsafe chemical reactions. The control of temperature is especially critical to the polymerization process. Even the initial temperatures of the monomer and catalyst are controlled before they are introduced into the mold. During the entire process, the temperature of the reacting material is monitored and controlled to ensure the heating and cooling cycles are the proper temperature and duration.
Samples of finished acrylic materials are also given periodic laboratory analysis to confirm physical, optical, and chemical properties.
Toxic Materials, Safety Considerations, and Recycling
Acrylic plastics manufacturing involves highly toxic substances which require careful storage, handling, and disposal. The polymerization process can result in an explosion if not monitored properly. It also produces toxic fumes. Recent legislation requires that the polymerization process be carried out in a closed environment and that the fumes be cleaned, captured, or otherwise neutralized before discharge to the atmosphere.
Acrylic plastic is not easily recycled. It is considered a group 7 plastic among recycled plastics and is not collected for recycling in most communities. Large pieces can be reformed into other useful objects if they have not suffered too much stress, crazing, or cracking, but this accounts for only a very small portion of the acrylic plastic waste. In a landfill, acrylic plastics, like many other plastics, are not readily biodegradable. Some acrylic plastics are highly flammable and must be protected from sources of combustion.
The average annual increase in the rate of consumption of acrylic plastics has been about 10%. A future annual growth rate of about 5% is predicted. Despite the fact that acrylic plastics are one of the oldest plastic materials in use today, they still hold the same advantages of optical clarity and resistance to the outdoor environment that make them the material of choice for many applications.
Additives A diverse group of specialty chemicals incorporated into plastic formulations before or during processing, or to the surfaces of finished products after processing. Their primary purpose is to modify the behavior of plastics during processing or to impart useful properties to fabricated plastic articles. (Modern Plastics Encyclopedia 1995).
Advanced Recycling Technologies (ART)
Processes that yield a variety of versatile and marketable end-products that are the building blocks from which new plastics and a variety of other products can be manufactured. This is achieved by converting or recycling plastics back into the raw materials from which they were made. ART includes such processes as methanolysis, glycolysis, hydrolysis, and thermal depolymerization. These technologies augment existing mechanical systems as part of an integrated approach to plastics recycling designed to increase the volume of post-consumer plastic plastics diverted from the waste stream and expand the variety of plastics that are recycled into new and useful products. (The Evolution of Plastics Recycling Technology, 1994).
American Chemistry Council (ACC)
The American Chemistry Council represents the leading companies engaged in the business of chemistry. ACC members apply the science of chemistry to make innovative products and services that make people's lives better, healthier and safer. ACC is committed to improved environmental, health and safety performance through Responsible Care®, common sense advocacy designed to address major public policy issues, and health and environmental research and product testing. ACC's Plastics Division represents leading manufacturers of plastic resins.
A complete depolymerization process that breaks nylon into its building blocks or monomers that can then be repolymerized to make nylon in any form and for any market. (Modern Plastics Encyclopedia 1995).
Automatic Plastics Sorting
The separation of mixed plastics by resin type and/or color via a mechanical system. A system detects the plastic type (or types) to be segregated and removes those materials from the stream. Common systems utilize conveyors, resin/color detectors, computer analysis and tracking and air jet ejectors. For plastic packaging, the separation may be on a macro (whole container) or micro (chopped/ground particles) basis. ("Automatic Sorting for Mixed Plastics," Peter Dinger, BioCycle, March 1992; "Automatic Microsorting for Mixed Plastics," Peter Dinger, BioCycle, April 1992).
The end product of a compaction process that is used to decrease the volume that material occupies by increasing the density and weight. Bales are typically 3' x 4' x 5' and must be bound with plastic stripping or wire to keep from falling apart. (Waste Reduction Strategies for Rural Communities, prepared by the MaCC Group, with support from Tennessee Valley Authority, March 1994).
An intermediate used in the production of epoxy, polycarbonate and phenolic resins. The name was coined after the condensation reaction by which it may be formed--two (bis) molecules of phenol with one of acetone (A). (Whittington's Dictionary of Plastics, published by Technomic Publishing).
A widely used process for the production of hollow thermoplastic shapes. The process is divided into two general categories: extrusion blow molding and injection blow molding. These processes are typically used to manufacture plastic bottles and containers. (Modern Plastics Encyclopedia 1995)
Extrusion Blow Molding: A parison or tube of plastic material is dropped or lowered from an extruder. Mold halves close around the parison, which is then expanded against the cavity wall by the injection of air. (Modern Plastics Encyclopedia 1995)
Injection Blow Molding: A two-stage process where plastic is first injection molded into a preform. The preform is then transferred to a blow mold where it is expanded. (Modern Plastics Encyclopedia 1995).
British Thermal Unit (Btu)
The quantity of heat required to increase the temperature of one pound of water one degree Fahrenheit. (The Recycler's Lexicon: A Glossary of Contemporary Terms and Acronyms, Resource Recycling Inc., 1995).
Buy-Back Recycling Centers
A commercially located, staffed recycling facility that purchases small amounts of post-consumer plastic secondary materials from the public. Buy-back centers typically purchase aluminum cans and may also handle glass containers and newspaper. Typically, little processing of materials occurs at buy-back centers. (The Recycler's Lexicon: A Glossary of Contemporary Terms and Acronyms, Resource Recycling Inc., 1995).
The act of picking up post-consumer plastic (or secondary) materials or compostable materials simultaneously with garbage. (The Recycler's Lexicon: A Glossary of Contemporary Terms and Acronyms, Resource Recycling Inc., 1995).
The simultaneous combustion of two or more fuel types to provide useful energy. Generally, a primary fuel is combusted with one or more supplemental fuels. Examples would include the co-combustion of wood with coal, or processed combustible materials derived from residential, commercial and industrial sources, which could include plastics-enhanced pelletized fuel products, with coal as the primary fuel in industrial or utility boilers. (Kenneth Smith, Vice President, wTe Corporation, Bedford, Mass., 1996).
Involves a process where parts are blow-molded with walls containing two or more layers of different material. Coextrusion offers wide latitude for material selection and also allows the use of recycled materials. A material with good barrier properties, for example, can be used for the inside and outside surfaces of a blow molded bottle, while recycled material can be used for the internal layer. (Modern Plastics Encyclopedia 1995).
The simultaneous production of power and another form of useful thermal energy from a single fuel-consuming process. The most common cogeneration systems being constructed today utilize combustion or co-combustion processes to produce electricity via a turbine as the principal product and steam and/or hot water as by-products. The electricity generally is sold to a utility or used for adjacent industrial processes and the steam and hot water generally are exported to adjacent companies for industrial process uses and for space heating. When combusting fuels in typical boilers, cogeneration is significantly more energy efficient than the generation of electricity alone. Approximately 75 percent of the energy value in the fuel can be extracted in a cogeneration facility compared to approximately 35 percent when electricity is produced solely. (Singer, Joseph G., "Combustion Fossil Power," Fourth Edition, Combustion Engineering, Inc., Windsor, Conn., 1991; Lund, Herbert F., "The McGraw-Hill Recycling Handbook," McGraw-Hill, Inc., New York, 1993).
A chemical process in which oxygen rapidly combines with the fuel and converts the fuel into gases, primarily water (H20) and carbon dioxide (C02), and residues. The combustion process produces significant thermal energy (heat) and light, and generally is self sustaining-that is no external source of heat is required to maintain combustion of fuel. In modern, state-of-the-art waste-to-energy facilities, and in other modern energy production facilities, the combustion process is carefully controlled to extract maximum energy value from the fuel source and to reduce the generation of potentially harmful substances significantly well below stringent regulatory levels. Industrial and post-consumer plastic plastics that cannot be economically recycled are excellent fuel sources that combust very well in such facilities. The energy value of these plastics is comparable to oil and can be more than 50 percent greater than coal. (Tchobanoglous, George, Hilary Theisen and Rolf Eliassen, "Solid Wastes, Engineering Principles and Management Issues," McGraw-Hill, Inc., New York, 1977; Lund, Herbert F., "The McGraw-Hill Recycling Handbook," McGraw-Hill, Inc., New York, 1993).
Additives that enable two or more materials to exist in close and permanent association indefinitely. They may be used to blend virgin and post-consumer plastic resins or different types of resins to maintain the quality of the products. (Dr. Ronald Liesemer, Vice President of Technology, Washington, D.C., 1996).
The incorporation of additional ingredients needed for processing in order to have optimal properties. These ingredients may include Additives to improve a polymer's physical properties, stability or processability. Compounding is usually required for recycled materials for the following reasons:
Recycled materials are typically ground from parts that produce flakes. The compounding (pelletizing) process turns them into pellets that can be more easily handled by traditional plastics processing equipment.
It allows Additives to be compounded into the recycled material to meet target application requirements.
It allows virgin materials to be mixed with recycled materials to meet material specifications for performance and recycled material content targets.
It provides a very important homogenization step. Recycled materials are usually a mix of many different grades of the same basic material. Even though the materials might be from the same family, differences in molecular weight, copolymer ratios, etc. can lead to a mixed material having poor homogeneity. The intensive physical mixing in a molten polymer that is achieved during extrusion can homogenize different grades of materials and even some types and amounts of foreign material that might not have been removed during the recycling process. (Adapted from Modern Plastics Encyclopedia 1995).
A methodology that quantifies energy consumption and environmental emissions at each stage of a product's life cycle, beginning at the point of raw material extraction and proceeding through processing, manufacturing, consumer use, and final recycling, reuse or disposal. (Resource and Environmental Profile Analysis of High Density Polyethylene and Bleached Paperboard Gable Milk Containers, Franklin Associates, Ltd., February 1991)
A collection process where consumers place designated recyclables at the roadside or curb, usually in a special container or bag, for collection separate from non-recyclable material such as garbage. (The Blueprint for Plastics Recycling, The Council for Solid Waste Solutions, 1991).
A process that lowers the volume-to-weight ratio in order to reduce shipping costs. Baling is the most common form of densification, although some handlers of post-consumer plastic plastics granulate or grind collected material. (The Blueprint for Plastics Recycling, The Council for Solid Waste Solutions, 1991).
Design for Recycling
This concept aims to encourage pre-production planning for safe and efficient recycling by the elimination, to the extent possible, of hazardous and non-recyclable materials from the production process. (Design For Recycling: The Scrap Recycling Industry's Perspective, Institute of Scrap Recycling Industries, Inc. (ISRI), 1991).
Dioxin is a naturally occurring compound and a by-product of environmental events such as volcanoes and forest fires. man-made processes such as manufacturing, paper and pulp bleaching, and exhaust emissions also yield dioxin. To find out more, go to the Chlorine Chemistry Division.
The components of Municipal Solid Waste (MSW) remaining after recovery for recycling and composting. These discards are presumably combusted or disposed of in landfills, although some MSW is littered, stored, disposed of on site or burned on site, particularly in rural areas. (Characterization of Municipal Solid Waste in the United States: 1995 Update, prepared for U.S. EPA Municipal and Industrial Solid Waste Division Office of Solid Waste, March 1996).
A centrally located depot to which consumers bring recyclables that does not provide payment for delivered materials. (The Blueprint for Plastics Recycling, The Council for Solid Waste Solutions, 1991).
Consumer products with a useful life of three years or more that include major appliances, furniture, tires, lead-acid automotive batteries, consumer electronics, automobiles and other items. (Characterization of Municipal Solid Waste in the United States: 1995 Update, prepared for U.S. EPA Municipal and Industrial Solid Waste Division Office of Solid Waste, March 1996).
Any product that utilizes post-consumer plastic plastic in its manufacture. (Adapted from Modern Plastics Encyclopedia 1995)
A fabricated value-added item that does not include Bales, flake or pellets. (1995 post-consumer plastic Plastics Recycling/Recovery Rate Survey, Glossary of Terms, R.W. Beck & Associates).
For more information on the theory of endocrine disruption go to the Canadian Chemical Producers Association, the American Chemistry Council, or the Bisphenol-A Web Site sponsored by the Global Bisphenol-A Industry Group of The Society of the Plastics Industry, Inc. and the European Chemical Industry Council (CEFIC).
The process of recovering the thermal energy produced when fuels are converted to gases and residues through the combustion process. The thermal energy generally is recovered through the use of heat exchangers that extract the energy from the hot combustion gases. Heat exchangers can be air to air units similar to those used in residential or commercial hot air heating systems or air to water/steam units (boilers) that can be designed to generate either hot water or steam, similar to residential and commercial hot water and steam generation heating systems. Large electric power production facilities, including modern waste-to-energy plants, that supply needed power to our homes, hospitals and factories, maximize thermal energy recovery efficiency through the utilization of high temperature, high pressure steam generating boilers that recover both the radiant energy from the combustion process inside the furnace as well as the energy in the hot combustion gases. The high heating value of plastics makes them a valuable source of energy that can be readily recovered in modern waste-to-energy plants. (Tchobanoglous, George, Hilary Theisen and Rolf Eliassen, "Solid Wastes, Engineering Principles and Management Issues," McGraw-Hill, Inc., New York, 1977; Gershman, Brickner & Bratton, Inc., "Small-Scale Municipal Solid Waste Energy Recovery Systems," Van Nostrand Reinhold Company, New York, 1986).
Environmental Marketing Guidelines
U.S. Federal Trade Commission (FTC) Guides for the Use of Environmental Marketing Claims, issued in July, 1992, are voluntary guidelines for product manufacturers using environmental advertising and marketing. They are intended to help prevent misleading environmental marketing claims. (Environmental Packaging; U.S. Guide to Green Labeling, Packaging and Recycling. Thompson Publishing Group, October 1995).
One of the most common plastics processing techniques covering a vast range of applications in which resins are melted, heated and pumped for processing. Extrusion machines accomplish these tasks by means of one or more internal screws. In extrusion, the material to be processed is sheared between the root of the screw and the wall of the barrel that surround it. This process produces frictional energy that heats and melts the substance as it is conveyed down the barrel. Melted extrudate from the machine is further processed after the extrusion phase, which typically produces pellets, sheet, cast film, blown film, fibers, coatings, pipes, profiles or molded parts. (Modern Plastics Encyclopedia 1995).
A group of recycling technologies employing various processes that convert mixtures of plastics into petroleum feedstocks or raw materials that can be used in refineries and petrochemical facilities for making new products. These technologies augment existing mechanical systems as part of an integrated approach to plastics recycling designed to increase the volume of post-consumer plastic plastics diverted from the waste stream and expand the variety of plastics that are recycled into new and useful products. (The Evolution of Plastics Recycling Technology, 1994).
A figure that refers to the amount (weight, volume or percentage of the overall waste stream) of materials and products as they enter the waste stream and before materials recovery, composting or combustion takes place. (Characterization of Municipal Solid Waste in the United States: 1995 Update, prepared for U.S. EPA Municipal and Industrial Solid Waste Division Office of Solid Waste, March 1996).
A process that stops short of complete depolymerization, but breaks long polymer chains into short-chain oligomers that are repolymerized into virgin polymer. (Modern Plastics Encyclopedia 1995).
A size-reduction process used for production scrap, post-consumer plastic packaging, industrial parts, or other materials that must be downsized for further processing. Granulators consist of a feed hopper, cutting chamber, classifying screen, and rotating knives that work in concert with stationary-bed knives to reduce the plastic scrap until it is small enough to pass through the classifying screen. The resulting particles, called regrind, can vary in size from 3 mm to 20 mm. (Modern Plastics Encyclopedia 1995).
Germany's Packaging Ordinance of June 12, 1991, designed to eliminate any packaging that cannot be reused, recycled or incinerated for energy recovery. Its aim is to keep packaging separate from the municipal waste stream by forcing retailers and distributors to take back used packaging materials and reuse, recycle or dispose of it. A private company established by industry to fulfill obligations under the Ordinance, Duales System Deutshland (DSD), guarantees that the packaging of participating members will be collected for reuse or recycling. In return, the products of DSD members can bear the "green dot." (Environmental Packaging; U.S. Guide to Green Labeling, Packaging and Recycling. Thompson Publishing Group, October 1995).e intensive physical mixing in a molten polymer that is achieved during extrusion can homogenize different grades of materials and even some types and amounts of foreign material that might not have been removed during the recycling process. (Adapted from Modern Plastics Encyclopedia 1995).
An organization that prepares recyclable plastics by sorting, densifying and/or storing the material until a sufficient quantity is on hand. When the handler completes processing, the material is not ready to be manufactured into a new product, but it has been made more valuable. (Waste Reduction Strategies for Rural Communities, prepared by the MaCC Group, with support from Tennessee Valley Authority, March 1994).
Hauler A company that transports post-consumer plastic and other materials to a handler or other processor. (Stretch Wrap Recycling: A How-To Guide, 1994).
High Density Polyethylene (HDPE)
HDPE refers to a plastic used to make bottles for milk, juice, water and laundry products. Unpigmented HDPE bottles are translucent and have good barrier properties and stiffness. They are well suited to packaging products with short shelf lives such as milk. Pigmented HDPE bottles generally have better stress crack and chemical resistance than bottles made with unpigmented HDPE. These properties are needed for packaging such items as household chemicals and detergents, which have a longer shelf life. Injection-molded HDPE is resistant to warpage and distortion. It is used for products such as margarine tubs and yogurt containers. (Plastic Packaging Opportunities and Challenges, February 1992).
Any plastic resin or products, such as factory regrind and plant scrap, recycled outside of the primary manufacturing facility. Also referred to as post-industrial or pre-consumer plastics. (1995 post-consumer plastic Plastics Recycling/Recovery Rate Survey, Glossary of Terms, R.W. Beck & Associates).
A process that involves transmitting melted resin into a mold's cavity; the molten resin then cools and solidifies, and the finished piece is ejected from the mold. (Modern Plastics Encyclopedia 1995).
Life Cycle Assessment (LCA)
An objective process to evaluate the environmental burdens associated with a product, process or activity by identifying and quantifying energy and materials used and wastes released to the environment, to assess the impact of those energy and materials uses and releases on the environment, and to evaluate and implement opportunities to affect environmental improvements. The assessment includes the entire life cycle of the product, process or activity, encompassing extraction and processing of raw materials, manufacturing, transportation and distribution, use/reuse/maintenance, recycling and final disposal. (A Technical Framework for Life-Cycle Assessment, Society of Environmental Toxicology and Chemistry (SETAC), January 1991).
Life Cycle Inventory (LCI)
An objective, data-based process of quantifying energy and raw material requirements, air emissions, waterborne effluents, solid waste, and other environmental releases incurred throughout the life cycle of a product, process or activity. (A Technical Framework for Life-Cycle Assessment, Society of Environmental Toxicology and Chemistry (SETAC), January 1991).
Linear Low Density Polyethylene (LLDPE)
A plastic that is used predominantly in film applications due to its toughness, flexibility and relative transparency. LLDPE is the preferred resin for injection molding because of its superior toughness and is used in items such as grocery bags, garbage bags and landfill liners. (Adapted from Modern Plastics Encyclopedia 1995; Plastic Packaging Opportunities and Challenges, February 1992).
Low Density Polyethylene (LDPE)
A plastic used predominantly in film applications due to its toughness, flexibility and relative transparency. LDPE has a low melting point, making it popular for use in applications where heat sealing is necessary. Typically, LDPE is used to manufacture flexible films such as those used for plastic retail bags and garment dry cleaning and grocery bags. LDPE is also used to manufacture some flexible lids and bottles, and it is widely used in wire and cable applications for its stable electrical properties and processing characteristics. (Adapted from Modern Plastics Encyclopedia 1995).
An advanced recycling process where methanol is introduced to PET or other polyester-based material in a chemical processing plant. The polyester is broken down into its basic molecules, including dimethyl terephthalate and ethylene glycol. These precursors are then re-polymerized into purified raw resin. (Modern Plastics Encyclopedia 1995).
Materials Recovery Facility (MRF)
A facility that receives materials in a form unacceptable by the marketplace. The MRF separates, removes contamination, sorts, densifies, and stores recyclable material types. Each material is prepared to meet the requirements of a specific market. MRFs are generally considered handlers. (Waste Reduction Strategies for Rural Communities, prepared by the MaCC Group, with support from Tennessee Valley Authority, March 1994).
A relatively simple compound that can react to form a polymer (i.e., polymerize). (Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., edited by Michael L. Berins).
Municipal Solid Waste (MSW)
A phrase for garbage generated from residential, commercial, institutional and industrial sources that falls into six basic categories-durable goods, non-durable goods, containers and packaging, food wastes, yard trimmings and miscellaneous organic and inorganic wastes. Wastes from these categories include appliances, newspapers, clothing, food scraps, boxes, disposable tableware, office and classroom paper, wood pallets and cafeteria wastes. (Characterization of Municipal Solid Waste in the United States: 1994 Update, prepared for U.S. EPA Municipal and Industrial Solid Waste Division Office of Solid Waste, November 1994).
Consumer goods with a useful life of less than three years that include newspapers, paper towels, plastic cups and plates, disposable diapers, clothing, footwear and other items. (Characterization of Municipal Solid Waste in the United States: 1994 Update, prepared for U.S. EPA Municipal and Industrial Solid Waste Division Office of Solid Waste, November 1994).
Office of Science Technology Policy (OSTP)
Established within the Executive Office of the President, OSTP "serves as a source of scientific, engineering, and technological analysis and judgment for the president with respect to major policies, plans, and programs of the federal government." (The United States Government Manual 1993/94, P
A quantification of the efficiency by which competing packaging materials deliver product to market. It is derived by comparing the volume of product delivered per pound of packaging. It is one way to quantify the achievement of source reduction, i.e., delivering the most product per unit of packaging. ("Factoring the Value of Source Reduction into Packaging Use/Post-Use Economics," Ronald Perkins, Recycle 93 Sixth Annual Forum, Davos, Switzerland).
A process for producing a uniform particle size of virgin or recycled plastic resins. Molten polymer from an extruder is forced through a die to form multiple strands of resin (similar to the chopping of spaghetti from extruded dough). Traditionally the strands are pulled by nip rolls through a water bath to cool and solidify and then into a cutting chamber where they are chopped into approximately 1/4" lengths. Modern systems incorporate underwater pelletizers where the strands are cut by a rotating knife immediately upon exiting the die. This operation takes place in a closed head as water circulates through to cool and carry the pellets away. Both methods move the pellets to a dewatering/drying system prior to final packout. (Modern Plastics Encyclopedia 1995).
Phthalate Ester (o-phthalic ester)
Any of a large class of plasticizers produced byt he direct action of alcohols on phthalic anhydride. The phthalates are the most widely used of all plasticizers and are generally characterized by moderate cost, good stability, low toxicity and good all-around properties. (Whittington's Dictionary of Plastics, published by Technomic Publishing). To find out more go to the Phthalate Esters Panel's new website or visit the American Chemistry Council website. A special web site has been established to adress the facts about phthalates esters in toys. To find out more, go to www.vinyltoys.com.
(1) One of many high-polymeric substances, including both natural and synthetic products, but excluding the rubbers. At some stage in its manufacture, every plastic is capable of flowing, under heat and pressure if necessary, into the desired final shape. (2) Made of plastic; capable of flow under pressure or tensile stress. (Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., edited by Michael L. Berins, 1991).
A rigid container that is designed with a neck that is narrower than the body, normally used to hold liquids and emptied by pouring. (How To Develop a Viable post-consumer plastic Handling Business, 1993).
A thin flexible sheet that only holds a particular shape when supported. (How To Develop a Viable post-consumer plastic Handling Business, 1993).
When a host of different plastics, such as polyethylene, polypropylene, polyester, polystyrene, polyvinyl chloride, polyvinylidene dichloride (Saran), nylon, etc., provide containment, protection, information and utility-of-use (convenience) for commercial products. (Plastic Packaging Opportunities and Challenges, 1992).
Plastics Recovery Facility (PRF)
A facility that receives recyclable plastics and then separates, removes contamination, sorts by resin type and color, condenses, and stores the segregated plastic types. Sorted plastic bottles and containers are then Baled and shipped to recycling markets. (Q & A: Plastics Recovery Facility fact sheet, The Garten Foundation, 1994).
Polyethylene Terephthalate (PET or PETE)
PET is clear, tough and has good gas and moisture barrier properties. Some of this plastic is used in PET soft drink bottles and other blow molded containers, although sheet applications are increasing. Cleaned, recycled PET flakes and pellets are in great demand for spinning fiber for carpet yarns and producing fiberfill and geotextiles. Other applications include strapping, molding compounds and both food and non-food containers. (Adapted from Modern Plastics Encyclopedia 1995).
A high-molecular-weight organic compound, natural or synthetic, whose structure can be represented by a repeated small unit, the monomer (e.g., polyethylene, rubber, cellulose). Synthetic polymers are formed by addition or condensation polymerization of monomers. If two or more different monomers are involved, a copolymer is obtained. Some polymers are elastomers, some plastics. (Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., edited by Michael L. Berins, 1991).
Polypropylene has excellent chemical resistance, is strong and has the lowest density of the plastics used in packaging. It has a high melting point, making it ideal for hot-fill liquids. In film form it may or may not be oriented (stretched). PP is found in everything from flexible and rigid packaging to fibers and large molded parts for automotive and consumer products. (Adapted from Modern Plastics Encyclopedia 1995; Plastic Packaging Opportunities and Challenges, February 1992).
Polystyrene is a very versatile plastic that can be rigid or foamed. General purpose polystyrene is clear, hard and brittle. It has a relatively low melting point. Typical applications include protective packaging, containers, lids, cups, bottles, trays and tumblers. (Plastic Packaging Opportunities and Challenges, February 1992).
Any plastic that has entered the stream of commerce, served its intended purpose, and has now been diverted for recycling or export. This includes residential, commercial and institutional plastic. This does not include industrial scrap material like factory regrind and plant scrap used within the primary manufacturing facility. (post-consumer plastic resin is also known as PCR). (1995 post-consumer plastic Plastics Recycling/Recovery Rate Survey, Glossary of Terms, R.W. Beck & Associates).
Process Engineered Fuels (PEF)
PEF, (some known as pellet fuels), are produced from a mixture of industrial and/or commercial plastic scrap and other industrial and/or commercial scrap materials and/or from plastic and other materials diverted from the waste stream, along with binding agents and Additives. The proportions of the major plastic and other components can be varied to yield a pellet fuel possessing the desired combustion characteristics. PEF is designed to provide a highly predictable and uniform Btu content, burn rate and flame temperature, and PEF of a particular composition will yield ash with known characteristics. (Comments of the Plastics Division on Proposed Revisions to Title V Operating Permit Regulations, submitted to the U.S. EPA, October 30, 1995).
The thermal decomposition of organic material through the application of heat in the absence of oxygen. (The Recycler's Lexicon: A Glossary of Contemporary Terms and Acronyms, Resource Recycling Inc., 1995).
An organization that further processes recyclable materials. When the reclaimer finishes processing, the material is ready to be remanufactured into a new product. Reclaimers sell post-consumer plastic pellets or flake to product manufacturers. Some reclaimers also manufacture end products. (Waste Reduction Strategies for Rural Communities, prepared by the MaCC Group, with support from Tennessee Valley Authority, March 1994).
Materials and by-products that have been recovered (or diverted) from solid waste. It does not include those materials and by-products generated from and commonly reused within an original manufacturing process (industrial scrap). (Standard Classification for Recycled post-consumer plastic Polyethylene Film Sources for Molding and Extrusion Materials, American Society for Testing and Materials (ASTM), April 1994).
The process of obtaining materials or energy resources from solid waste. (Code of Federal Regulations, Title 40, 245.101).
The series of activities by which discarded materials are collected, sorted, processed and converted into raw materials and used in the production of new products.
Individuals or businesses that purchase post-consumer plastic and/or post-industrial recyclable materials. Markets specify what kind of recyclables they purchase, what price the material is worth and in what form the material is needed. Recycling markets for plastics fall into two broad categories: See Handlers and Reclaimers. (Waste Reduction Strategies for Rural Communities, prepared by the MaCC Group, with support from Tennessee Valley Authority, March 1994).
A centrally located depot to which consumers bring recyclables that provides payment for delivered materials. (The Blueprint for Plastics Recycling, The Council for Solid Waste Solutions, 1991).
Any of a class of solid or semi-solid organic products of natural or synthetic origin, generally of high molecular weight with no definite melting point. Most resins are polymers. (Plastics Engineering Handbook of The Society of the Plastics Industry, Inc., edited by Michael L. Berins, 1991).
A wide array of activities that include reducing the energy consumed and pollution generated during manufacture and over the useful life of a product; extending the life of material used to make a product through reuse and recycling; reducing the amount of material needed to make a product initially; utilizing options available for recovering value from materials when they are ultimately discarded, such as energy recovery and fuel pellets. (ACC's Plastics Division, Washington, DC, 1996).
Responsible Care is a global chemical industry performance initiative that is implemented in the United States through the American Chemistry Council and is a mandatory program for ACC members. Responsible Care helps America’s leading chemical companies go above and beyond government requirements and openly communicate their results to the public. Through Responsible Care, these companies are making available the most performance information of any private sector industry group.
Rigid Plastic Container
A formed or molded plastic container that serves as a package, and maintains its shape when empty and unsupported. (How To Develop a Viable post-consumer plastic Handling Business, 1993).
Society of Plastics Engineers, Inc. (SPE)
A technical society for the plastics industry that is a preferred supplier of engineering, scientific and business knowledge required by the SPE membership. Its goal is to promote this knowledge and increase education of plastics and polymers worldwide. (Leadership 2000: Strategies for the Next Century, SPE, 1996).
Society of the Plastics Industry, Inc. (SPI)
A trade organization of more than 2,000 members representing all segments of the plastics industry in the United States. SPI's operating units and committees are composed of resin manufacturers, distributors, machinery manufacturers, plastics processors, moldmakers and other industry-related groups and individuals. (SPI Boilerplate, 1996).
Garbage, refuse, sludges, and other discarded solid materials resulting from industrial and commercial operations and from community activities. It does not include solids or dissolved material in domestic sewage or other significant pollutants in water resources, such as silt, dissolved or suspended solids in industrial wastewater effluents, dissolved materials in irrigation return flows or other common water pollutants. (Code of Federal Regulations, Title 40, §240.101).
The design, manufacture, use or reuse of materials or products (including packages) to reduce their amount or toxicity throughout their useful life and when they are reused, recycled, landfilled or incinerated. Because it is intended to reduce pollution and conserve resources, source reduction should not increase the net amount or toxicity of wastes generated throughout the life of a product. Source reduction is sometimes referred to as waste prevention. (National Recycling Coalition: Definitions Approved by NRC Board of Directors, September 10, 1995).
The sorting of individual secondary materials at the point of collection or generation for recycling. Many curbside recycling programs require the hauler to separate paper, glass, metal cans and plastic containers into their appropriate bins on the truck when collected. (The Recycler's Lexicon: A Glossary of Contemporary Terms and Acronyms, Resource Recycling Inc., 1995).
Stabilizers increase both virgin resin's and post-consumer plastic plastic's strength and resistance to degradation. Heat stabilizers provide resistance to thermal degradation during periods of exposure to elevated temperatures. Thermal degradation is reduced not only during processing but also during the useful life of the finished products. Light stabilizers are used in a variety of resins to limit the effects of sunlight or other sources of ultra violet radiation. Antioxidants can be used as sacrificial Additives to protect plastics from oxidizing environments. Stabilizers are important for post-consumer plastic plastics because reprocessing exposes the material to additional heat histories through compounding and molding. It is also important to replenish sacrificial Additives that might have been expended during the material's previous application and/or during the added heat histories. (Adapted from Modern Plastics Encyclopedia 1995).
Styroform is a trademarked name for a specific form of insulation manufactured by The Dow Chemical Company. "STYROFOAM" is not synonymous with "polystyrene."
To meet the needs of the present without compromising the ability of future generations to meet their own needs. (The World Commission on Environment and Development, Our Common Future, Oxford University Press, 1987).
The process of heating a thermoplastic sheet to a working temperature and then forming it into a finished shape by means of heat or pressure. (Modern Plastics Encyclopedia 1995).
(1) Capable of being repeatedly softened by heat and hardened by cooling. (2) A material that will repeatedly soften when heated and harden when cooled. Typical of the thermoplastic family are the styrene polymers and copolymers, acrylics, cellulosics, polyethylenes, polypropylene, vinyls and nylons. (Plastics Engineering Handbook of The Society of the Plastics Industry, Inc., edited by Michael L. Berins, 1991).
A material that will undergo or has undergone a chemical reaction through the application of heat and pressure, catalysts, ultraviolet light, etc., leading to a relatively infusible state. Typical of the plastics in the thermosetting family are the aminos (melamine and urea), most polyesters, alkyds, epoxies, and phenolics. (Plastics Engineering Handbook of The Society of the Plastics Industry, Inc., edited by Michael L. Berins, 1991).
Also known as variable rate pricing or pay-as-you-throw, is a system under which residents pay for municipal waste management services by unit of waste collected rather than through a fixed fee. Note: 1) Costs under unit pricing systems can be allocated based on either volume or weight; 2) Fixed fee systems usually collect such fees through property taxes regardless quantity of waste collected. (Pay-As-You-Throw; Lessons Learned About Unit Pricing. U.S. EPA Office of Solid Waste and Emergency Response, EPA530-R-94-004, April 1994).
Vinyl (Polyvinyl Chloride or PVC)
In addition to its stable physical properties, PVC has excellent transparency, chemical resistance, long-term stability, good weatherability, flow characteristics and stable electrical properties. The diverse slate of vinyl products can be broadly divided into rigid and flexible materials. Rigid applications, accounting for 60 percent of total vinyl production, are concentrated in construction markets which include pipe and fittings, siding, carpet backing and windows. Bottles and packaging sheet are also major rigid markets. Flexible vinyl is used in wire and cable insulation, film and sheet, floor coverings, synthetic-leather products, coatings, blood bags, medical tubing and many other applications. (Adapted from Modern Plastics Encyclopedia 1995).
The conversion and recovery of the energy value in waste materials through the application of high temperature, controlled combustion. The recovered thermal energy can then be converted to electrical energy in steam driven turbine generators for plant use and for export/sale, or it can be exported and sold directly as steam or hot water for industrial processes and space heating. The recovered energy also can be used to generate chilled water for industrial processes or air conditioning. Most waste-to-energy projects employ combustion facilities specifically designed to accommodate the anticipated waste deliveries. These state-of-the-art, dedicated boilers are designed to extract the maximum energy value from the delivered waste materials and to simultaneously reduce the generation of potentially harmful gases and residues from the combustion process to well below stringent regulatory levels. The waste materials routinely delivered to such facilities include municipal solid wastes (MSW) such as residential and commercial wastes; non-hazardous institutional wastes; and non-hazardous, non-manufacturing industrial solid wastes. Industrial plastic wastes and post-consumer plastic plastics that cannot be economically recycled provide an excellent source of fuel for waste-to-energy facilities. There are other waste-to-energy projects that utilize existing, appropriately modified industrial or utility boilers to combust specially prepared fuels derived from solid wastes-these are called refuse derived fuels, or RDF. (Integrated Waste Services Association, "Waste Energy," IWSA, Washington, Date Unknown; Keep America Beautiful, Inc., "Overview: Solid Waste Disposal Alternatives," KAB, Inc., Stamford, Conn., April 1989).
A program initiated by EPA in 1994 to assist businesses in taking cost-effective actions to reduce solid waste through waste prevention, recycling collection, and buying or manufacturing recycled products. (Waste Wi$e; EPA's Voluntary Program for Reducing Business Solid Waste. U.S. EPA Office of Solid Waste and Emergency Response, EPA530-F-93-018, October 1993).
What is a Polymer?
www.qureshiuniversity.com/polymers.html How are plastics made?