Reusing Plastics

F. Henry Firsching
School of Sciences
Southern Illinois University
at Edwardsville

Plastics are synthetic materials that have been mostly developed within the past 50 years. This is such a short time that no organisms or micro-organisms have evolved that might feed on these materials. When placed in landfills, plastics persist for indefinite periods of time.

Plastics represent a significant part of overall trash; about seven percent by weight of all trash is classified as plastic. But by volume plastics represent about 20 to 30 percent, because so much of the plastics are empty bottles or containers. The total weight of plastic trash is about 30 billion pounds annually, or 15 million tons.

Currently, about one billion pounds are recycled, about three percent of the total. That is not enough reuse. We must do better than that.

There are about five basically different types of plastics, and normally they cannot all be used together. For example: polyethylene, used in bread wrappings and dry cleaning bags, is a soft, pliable material. Polyvinyl chloride, used for floor tiles, is hard and somewhat brittle, while nylon is a totally different item. If reuse involves putting all these together, only limited applications are possible.

The Europeans are about ten years ahead of Americans in handling this problem. They have developed this technology for sorting out various types of plastics. Once separated, a specific plastic will have specific uses.

One successful application for reused plastic is in construction materials for homes and other buildings. Mixed plastics, items that cannot be sorted out satisfactorily, are fused together to make boards of plastic. These boards are relatively inexpensive when compared to lumber, and, no organisms or micro-organisms attack them. Termites cannot feed on them, nor can anything else.

Plastic boards appear to be a major use of mixed plastics. And these boards can be produced in very large quantities.

More imaginative uses for plastics are possible. The makers of Spic and Span cleaner are planning to put all cleaners in bottles made of recycled plastics. The Chrysler Corporation is going to make fenders on 1992 vans from recycled soft drink bottles.

Other possible uses include: carpets, fibers, fiber-fill stuffing, carstops in parking lots, piping, planters for flowers, highway signs, etc. Reusing plastics will have a two-fold impact. Massive trash problems will be reduced and energy requirements needed to make new plastics will also be reduced. And, both of these problems, trash and energy, need all the help they can get.