- Dan LaMee via Flickr
- According to the Colorado-based EcoCycle, the use of disposable packaging - especially plastic - has increased by more than 10,000 percent over the past 50 years. Pictured: plastics headed for sorting and recycling.
Courtesy of: EarthTalk®
E — The Environmental Magazine
Dear EarthTalk: Why can’t plastics of all types, instead of being initially sorted, simply be melted together to be separated later? It must be a monumental and error-prone task to separate truckloads of plastics. — L. Schand, via e-mail
The reason plastics aren’t typically melted together and then separated later is a matter of both physics and economics. When any of the seven common types of plastic resins are melted together, they tend to separate and then set in layers. The resulting blended plastic is structurally weak and difficult to manipulate. While the layered plastic could in theory be melted again and separated into its constituent resins, the energy inputs required to do so would make such a process cost prohibitive.
As a result, recycling facilities sort their plastics first and then melt them down only with other items made of the same type of resin. While this process is labor-intensive, the recycling numbers on the bottom of many plastic items make for quicker sorting. Many recycling operations are not only reducing sizable amounts of waste from going into landfills but are also profitable if managed correctly.
This article appears in Jul 28 – Aug 3, 2011.