11:32 am - Monday May 28, 2012

Plastic Recycling

Plastic RecyclingPlastic recycling is the process of recovering scrap or waste plastics and reprocessing the material into useful products, sometimes completely different in form from their original state. For instance, this could mean melting down soft drink bottles and then casting them as plastic chairs and tables. Typically a plastic is not recycled into the same type of plastic, and products made from recycled plastics are often not recyclable.

Plastic Recycling Process

Before recycling, most plastics are sorted according to their resin type. In the past, plastic reclaimers used the resin identification code (RIC), a method of categorization of polymer types, which was developed by the Society of the Plastics Industry in 1988. Polyethylene terephthalate, commonly referred to as PET, for instance, has a resin code of 1. Most plastic reclaimers do not rely on the RIC now; they use automatic sort systems to identify the resin, such as near infrared (NIR) technology. Some plastic products are also separated by color before they are recycled. The plastic recyclables are then shredded. These shredded fragments then undergo processes to eliminate impurities like paper labels. This material is melted and often extruded into the form of pellets which are then used to manufacture other products.

Monomer Recycling : Many recycling challenges can be resolved by using a more elaborate monomer recycling process, in which a condensation polymer essentially undergoes the inverse of the polymerization reaction used to manufacture it. This yields the same mix of chemicals that formed the original polymer, which can be purified and used to synthesize new polymer chains of the same type. Du Pont opened a pilot plant of this type in Cape Fear, North Carolina, USA, to recycle PET by a process of methanolysis, but it closed the plant due to economic pressures.
Heat Xompression : Yet another process that is gaining ground with startup companies (especially in Australia, United States and Japan) is heat compression. The heat compression process takes all unsorted, cleaned plastic in all forms, from soft plastic bags to hard industrial waste, and mixes the load in tumblers (large rotating drums resembling giant clothes dryers). The most obvious benefit to this method is the fact that all plastic is recyclable, not just matching forms. However, criticism rises from the energy costs of rotating the drums, and heating the post-melt pipes.
Other Processes : A process has also been developed in which many kinds of plastic can be used as a carbon source in the recycling of scrap steel.

Plastic Recycling Facts

  • According to the Beverage Marketing Corp, the average American consumed 1.6 gallons of bottled water in 1976. In 2006, that number jumped to 28.3 gallons.
  • More than 2.4 billion pounds of plastic bottles were recycled in 2008. Although the amount of plastic bottles recycled in the U.S. has grown every year since 1990, the actual recycling rate remains steady at around 27 percent.
  • In 2007, more than 325 million pounds of wide-mouth plastic containers were recovered for recycling. (This included deli containers, yogurt cups, etc.)
  • In recent years, the number of U.S. plastics recycling business has nearly tripled. More than 1,600 businesses are involved in recycling post-consumer plastics.
  • Plastics in the U.S. are made primarily (70 percent) from domestic natural gas.
  • Plastic bags and product wraps (known collectively as “plastic film”) are commonly recycled at the many collection programs offered through major grocery stores.
  • Recycling 1 ton of plastic saves 7.4 cubic yards of landfill space.
  • During Keep America Beautiful’s 2008 Great American Cleanup, volunteers recovered and recycled 189,000,000 PET (plastic) bottles that littered highways, waterways and parks.
Be Sociable, Share!
<-- Google Analytics Start --> <-- Google Analytics End--> <-- Infolinks Start--> <-- Infolinks End-->