Recycling of Polyethylene Terephthalate Essay

1598 Words 7 Pages
Recycling of Polyethylene Terephthalate

In the United States, over 245 million tons of municipal solid waste (MSW) was produced by consumers in 2005. This is approximately 4.5 pounds of trash per person per day.[3] This same year, 79 million tons of waste were recycled, a dramatic increase from 15 million tons in 1980.[3] Of the total MSW in 2003,11.1% (26.7 million tons) was plastic. Although only 3.9% of plastics disposed in 2003 were recycled, PET was recovered at a rate of 25%.[4]
There are six classifications of plastics, each assigned a number. Numbers 1 and 2 are commonly recycled, 4 is recycled less, and the others are generally not recycled. The first is polyethylene terephthalate (PET).[2] PET is commonly used in
…show more content…
Other plastics, marked with a 7, are made of mixtures of plastics and have no recycling potential.[2]
The plastic Grace and I chose was polyethylene terephthalate. It is used for water and soft drink bottles, peanut butter jars, and other impact-resistant bottles as well as textiles.[1] PET is a semi-crystalline, thermoplastic polyester.[6] Its mechanical properties include excellent tensile and impact strength, chemical resistance, clarity, processability, color ability and thermal stability. PET is mechanically processed by extrusion, injection molding, and blow molding.[1] The post consumer PET recycling industry was initiated by the fact that it is non-degradable in nature, since its molecules are too large to decompose.[1] There are four methods of processing PET: primary, mechanical, chemical, and energy recovery.[6] Primary recycling is the most popular, inexpensive method as it deals only with uncontaminated, clean waste PET. This ensures a quality product. Mechanical recycling of PET consists of contamination removal and extrusion into the appropriate shape for the desired use after recycling. In contamination removal, the PET bottles are sorted, ground into flakes, and washed. PVC must be separated from bottles in order to keep the product as pure as possible.[1] After grinding, flakes are washed with water and detergent or a solvent. Flakes must be dried thoroughly in order to obtain a quality product. Finally, flakes are
Open Document