Plastics & The Environment
In addressing all the beneficial attributes of polymers, it is equally important to discuss some of the environmental aspects of the material. Plastics deteriorate but never decompose completely, but neither does glass, paper nor aluminum. Plastics make up 9.5 percent of our trash by weight compared to paper, which constitutes 38.9 percent. Glass and metals make up 13.9 percent by weight.
Applications for recycled plastics are growing every day. Recycled plastics can be blended with virgin plastic (plastic that has not been processed before) to reduce cost without sacrificing properties.
Recycled plastics are used to make polymeric timbers for use in picnic tables, fences, and outdoor toys, thus saving natural lumber. Plastic from 2-litre bottles is even being spun into fibre for the production of carpet and fleece.
An option for plastics that are not recycled, especially those that are soiled, such as used microwave food wrap or diapers, can be an energy recovery system.
The controlled combustion of polymers produces heat energy. The heat energy produced by the combustion of plastics not only can be converted to electrical energy but can help burn the wet trash that is present. Paper also produces heat when combusted, but not as much as plastics. On the other hand, glass, aluminum and other metals do not release any energy when combusted.
To better understand the energy recovery process, consider the smoke coming off a burning object and then ignite the smoke with a Bunsen burner. Observe that the smoke disappears. This is not an illusion, but illustrates that the by-products of incomplete burning are still flammable. Energy recovery technologies can burn the material and the by-products of the initial burning.