Plastic recycling turns soft-drink bottles into - ski parkas?
Pine Brook, N.J. — BECAUSE of people like Frank Tammera, a self-taught chemical engineer and one-time grocer, the plastic bottle that held your favorite cola last week might just turn up in the TV set you buy next month or in the ski parka you pick out before heading for the slopes next winter. Mr. Tammera and others with similar skills have found that if they can intercept enough soft-drink bottles on the way to the dump or incinerator, they can make a good living processing them into the raw material for products ranging from box strapping and auto parts to fiberglass roofing. And they can do just as much with the high-impact plastic of the milk jug.
In the ongoing debate about what to do with mounting wastes, plastic is often seen as an insurmountable problem. Immune to bacterial attack, it can't be composted away; while it burns well, it also produces unwanted air pollutants. In addition, it doesn't recycle easily. Many plastics that look the same are not the same. They are made up of different polymers and resins that don't always blend well. While you can make new plastic supermarket shopping bags from old ones, and new paintbrushes from old bristles, you can make neither when the two plastics are mixed.
Plastic recycling, almost unheard of a few years back, is beginning to take off because people like Tammera have seen the opportunities and developed the technology to make it work. Where different plastics are readily recognized, they can be separated and recycled. Some experiments suggest that even mixed, straight-from-the-dump plastics can be used for certain molded products. A promising Swiss-German experiment incorporates mixed plastics and waste auto-tire rubber.
While plastic makes up between 5 and 7 percent of the waste stream in the United States (it is a considerably higher percentage in Europe), it makes up a much greater proportion by volume - the critical factor for a nation rapidly running out of acceptable landfill space. And plastic use is growing by the year.
Robert S. Weis of the DuPont Company in Delaware is president of the two-year-old Plastics Recycling Foundation, whose members fund research in plastic waste recovery. The research institute is at Rutgers University, in New Brunswick, N.J.
Pressure from state solid-waste managers concerned over the increasing volumes of bulky waste prompted the effort. But another important reason also spurred the developing trend in plastics recycling, Mr. Weis points out. Because plastics are derived almost entirely from natural gas or oil, they are a limited resource. ``Once disposed of by incineration or landfill they are gone forever - and so, too, are the hydrocarbons from which they were derived,'' he says. Recyling old plastic bottles into new products could save 50 to 60 percent of the energy required to manufacture the same product from raw material.
Initial research at Rutgers concentrated on the two most readily recognized (and therefore easily separable) products in the plastic waste stream - milk jugs and the more flexible carbonated beverage bottles. The system developed at Rutgers for grinding and separating the two plastics, the aluminum caps, and the paper from the labels is now being sold to would-be producers for a token $3,000. Meanwhile, several companies have developed proprietary recovery systems of their own. Tammera's Pure Tech Research Industries is one such.
Top-quality recovered plastic flakes can be used to make any product that virgin material is used for. By law, recovered plastic cannot be made into new beverage bottles or anything that holds food for human consumption. But a wide range of other manufacturing options remains. Carbonated beverage (polyethylene terephthalate, or PET) bottles are recycled into fiberfill for pillows, ski jackets, sleeping bags, and automobile seats. They can also be turned into package strapping, fiberglass bathtubs, shower stalls, swimming pools, corrugated awnings, appliance handles, power-tool housings, and electronic and automotive parts. Other products include floor tiles, kitchen scouring pads, and paintbrushes. This plastic can even be included as an ingredient in paint.
Leading products made from recovered high-density polyethylene (HDPE) plastic are lumber boards for rot-resistant boat piers, pig and calf pens, compost bins, and garden furniture. Flower pots, drainage pipes, toys, pails, drums, kitchen drain boards, and golf-bag liners are other products that started out as milk jugs or the base cups from carbonated beverage bottles.
Meanwhile, the Plastics Recycling Institute is tackling the next major hurdle in reclaiming old plastic by funding research in the coming year into the use of commingled plastics that would eliminate the need for time-consuming and costly separation procedures.
Already, some heavy molded products in which structural integrity isn't vital (parking bay barriers, patio blocks, fence posts) are being produced from mixed plastics on a limited scale. One option the Rutgers research program will investigate is the addition of cellulose fibers or other forms of reinforcing into mixed plastics to provide the necessary additional strength for thin-walled products.