You listen to them on your stereo, play them in your computer, or watch movies on them. Compact discs (CDs) and their faster cousin, digital video discs (DVDs) are everywhere! Only a few millimeters thick, they provide hours of entertainment and hold huge volumes of information. Do you ever stop to think about how CDs and DVDs are made, what materials are used, or what happens to these discs when you don't want them any more? Making products like CDs and DVDs consumes natural resources, produces waste, and uses energy. By learning about product life cycles, you can find out how to reduce the environmental impacts and natural resource use associated with products you use every day. When you understand these connections, you can make better environmental choices about the products you use, and how you dispose of them. Follow the life cycle of a CD or DVD on this poster to learn more about how these products are made and how you can help reduce their environmental impacts.
CDs and DVDs are made from many different materials, each of which has its own separate life cycle involving energy use and waste. They include:
- Aluminum-the most abundant metal element in the Earth's crust. Bauxite ore is the main source of aluminum and is extracted from the Earth.
- Polycarbonate-a type of plastic, which is made from crude oil and natural gas extracted from the Earth.
- Lacquer-made of acrylic, another type of plastic.
- Gold-a metal that is mined from the Earth.
- Dyes-chemicals made in a laboratory, partially from petroleum products that come from the Earth.
- Other materials such as water, glass, silver, and nickel.
Most mined materials must be processed before manufacturers can use them to make CDs or DVDs. For example:
- Bauxite ore is processed into a substance called "alumina" by washing, crushing, dissolving, filtering, and harvesting the materials. Alumina is then turned into aluminum through a process called "smelting." Then the metal is shaped, rolled, or made into a cast.
- To make plastics, crude oil from the ground is combined with natural gas and chemicals in a manufacturing or processing plant.
The manufacturing process described here is roughly the same for both CDs and DVDs.
- An injection molding machine creates the core of the disc-a 1-millimeter thick piece of polycarbonate (plastic). Polycarbonate is melted and put in a mold. With several tons of pressure, a stamper embeds tiny indentations, or pits, with digital information into the plastic mold. A CD-player's laser reads these pits when playing a CD.
- The plastic molds then go through the "metallizer" machine, which coats the CDs with a thin metal reflective layer (usually aluminum) through a process called "sputtering." The playback laser reads the information off of the reflective aluminum surface.
- The CD then receives a layer of lacquer as a protective coating against scratching and corrosion.
- Most CDs are screen printed with one to five different colors for a decorative label. Screen printing involves the use of many materials, including stencils, squeegees,and inks.
CDs and DVDs are packaged in clear or colored plastic cases (jewel cases) or cardboard boxes-that are then covered with plastic shrink wrap. This packaging can be made from recycled or raw materials. For example, the plastic used can be from recycled bottles or from crude oil and natural gas extracted from the Earth and combined with chemicals.
CDs and DVDs are created with materials that are extremely stable. If properly stored and handled, most discs will last for decades and probably centuries. Certain conditions, such as high humidity, or extended periods of high temperatures, rapid temperature changes, and exposure to certain types of light, can damage discs and shorten their useful life. Taking care of your discs by keeping them out of direct sunlight and away from heat and water will help them last longer. Not only will you save money, but you will also reduce the discs' environmental impacts by preventing waste.
Reuse, Recycling or Disposal
Depending on their condition, discs can be reused or recycled instead of thrown away.
A good way to keep discs out of the garbage is to reuse them:
- Minor scratches can be repaired by rubbing a mild abrasive (such as toothpaste) on the non-label side of a disc in a circular motion from the center out. Also, some commercial refinishers can inexpensively repair your CDs.
- Unwanted CDs or DVDs can be sold to some stores, traded with friends, or donated to schools, libraries, or other organizations. Buying used CDs and DVDs or borrowing them from the library can also help reduce the environmental impact associated with manufacturing new products.
CDs can be recycled for use in new products. Specialized electronic recycling companies clean, grind, blend, and compound the discs into a high-quality plastic for a variety of uses, including:
- Automotive industry parts.
- Raw materials to make plastics (Discs are ground into a gravel-like substance, which is sold to companies that melt it down and convert it to plastic).
- Office equipment.
- Alarm boxes and panels, street lights, and electrical cable insulation.
- Jewel cases.
There's no need to dispose of your discs now that you have a choice to send them to a collection center. Always try to share, donate, or trade your discs, and all this fails, send them to a recycling center. CDs and DVDs that are thrown away waste energy and result in lost valuable resources.
You constantly make decisions about buying products. One of your decisions probably involves weighing how much you want a product against how much it costs. This poster provides information to help you become a more environmentally aware consumer by describing the materials and energy consumption required to make CDs and DVDs. You should factor this information into your buying decisions and understand that nearly all of your choices have some environmental trade-offs. You might also want to consider whether the information you think you need on disc is actually available on the Internet. If it is, you might not need to buy the disc at all! Thinking about these issues will make you a more informed consumer and will help you make decisions that help to protect and preserve our environment.
Designing for the Environment
For a product to come into existence, it must be designed. And that design can have as much of an impact on the environment as any other step in a product's life cycle. For example, designers can plan for a product to be easily made from recycled materials, thus reducing the need to mine or gather raw materials. Most industries, including high-tech industries, have developed voluntary standards that many manufacturers follow when designing and manufacturing new products. These standards help make products as environmentally sound as is technologically possible. These standards also change as rapidly developing new technologies become available.
In 1983, when CDs were introduced in the United States, 800,000 discs were sold. By 1990, this number had grown to close to 1 billion!
More than 5.5 million boxes of software go to landfills and incinerators, plus people throw away millions of music CDs each year!
Every month approximately 100,000 pounds of CDs become obsolete (outdated, useless, or unwanted).
Why Are Product Life Cycles Important?
Each day, we use hundreds of products: clothes, shoes, books, newspapers, notebook paper, CD/DVD players, video games, cell phones, and TVs. Have you ever thought about what these products are made of , where their parts come from, or what happens to them when we're finished with them? Have you ever thought about the impact each of the products we use has on our environment?
Looking at a product's life cycle helps us understand the connections between the Earth's natural resources, energy use, climate change, and waste. Product life cycles focus on the processes involved in the entire production system-from extracting and processing raw materials, through the product's final use by consumers, recyclers, and disposers. By learning about product life cycles, we can see where and how everyone can collaborate to reduce the environmental impacts and natural resource use associated with a product. When we understand these connections, we can be better environmental stewards.
What Is a Life Cycle?
Just as living things are born, get older, and die, products also have a life cycle. Each stage of a product's development affects our environment in different ways-from the way we use products to the quantities of products we buy. Similarly, what we do with a product when we are finished with it has environmental effects. The stages of a product's life cycle usually include:
Engineers, designers, manufacturers, and others get ideas for products and then have to manufacture them. Most product designs are researched and tested before they are mass-produced. A product's initial design affects each stage of its life cycle, and therefore, its impact on our environment. For example, products designed to be reused instead of thrown out prevent waste and conserve natural resources.
Whether man-made or naturally occurring, all products are made from some raw materials. "Virgin" materials, such as trees or iron ore, are directly harvested or mined from the Earth, which causes climate change, uses large amounts of energy, and depletes our natural resources. Making new products from materials that were used in another product-known as recycled or recovered materials-can reduce pollution, energy use, and the amount of raw materials we need to take from the Earth. For example, using recycled steel products instead of mining virgin iron ore saves 1,400 pounds of coal, 120 pounds of limestone, and enough energy to power more than 18 million homes for one year!
Once materials are extracted from the Earth, they must be converted into a form that can be used to make products. For example, trees contribute the wood from which paper is made. The wood is made into paper from several different manufacturing processes. Each separate process creates waste and consumes energy. For example, making one ton of recycled paper uses 64 percent less energy and 50 percent less water; reduces air pollution by 74 percent; saves 17 trees; and creates five times more jobs than manufacturing one ton of paper products from virgin wood pulp.
Products are made in factories that use a great deal of energy. Manufacturing processes also create waste and often contribute to global climate change. Glass beverage containers, for example, can be used an infinite number of times, over and over again. More than 41 billion glass containers are made each year; recycling only one of those saves enough energy to light a 100-watt bulb for 4 hours. Imagine the energy savings from recycling all 41 billion containers. What's more, making 1 ton of glass from 50 percent recycled materials saves 250 pounds of mining waste.
Many products are packaged in paper or plastic, which also undergo separate manufacturing processes that use energy and consume natural resources. While packaging can serve several important functions, such as preventing tampering, providing information, and preserving hygienic integrity and freshness, sometimes packaging is excessive.
The way products are used impacts our environment. Reusable, durable, and recyclable products conserve natural resources, use less energy, and create less waste than disposable, single-use products. For example, fluorescent lamps reduce energy consumption because they are four to five times more efficient than incandescent bulbs. Reducing energy use also cuts down on power plant emissions that contribute to global climate change, acid rain, and smog. Properly caring for products also increases their useful life, so remember to read and follow the cleaning, operating, and maintenance instructions for the products you own-especially tires on your bicycles and other vehicles.
Recycling or remanufacturing products into new ones saves energy and reduces the amount of raw materials that have to be used in the manufacturing process. When products are reused or recycled, their life does not end; instead, it becomes a continuous cycle. For example, one pound of recycled paper can make six new cereal boxes, and five recycled soda bottles can make enough fiber fill to stuff a ski jacket.
Throwing products in the trash ends their useful life. We simply lose these valuable resources outright. If we recycled all our morning newspapers, we could save 41,000 trees a day, and we could keep 6 million tons of waste out of landfills.