Plastic Recycling
Bottles made of polyethylene terephthalate (PET, sometimes PETE) can be “recycled” to reuse the material out of which they are made and to reduce the amount of waste going into landfills. PET is semiporous and absorbs molecules of the food or beverage contained, and the residue is difficult to remove: Heating the plastic enough for sterilization would destroy it. Therefore, most recycled bottles are used to make lower grade products, such as carpets.[citation needed] To make a food grade plastic, the bottles need to be hydrolysed down to monomers, which are purified and then re-polymerised to make new PET.
In many countries, PET plastics are coded with the resin identification code number “1” inside the universal recycling symbol, usually located on the bottom of the container.
PET is used as a raw material for making packaging materials such as bottles and containers for packaging a wide range of food products and other consumer goods. Examples include soft drinks, alcoholic beverages, detergents, cosmetics, pharmaceutical products and edible oils. PET is one of the most common consumer plastics used.[1] Polyethylene terephthalate also can be used as main material in making paper.
Post-consumer waste
The empty PET packaging is discarded by the consumer after use and becomes PET waste. In the recycling industry, this is referred to as “post-consumer PET.” Many local governments and waste collection agencies have started to collect post-consumer PET separately from other household waste. Besides that there is container deposit legislation in some countries which also applies to PET bottles.
It is debatable whether exporting circulating resources that damages the domestic recycling industry is acceptable or not.[4] In Japan, overseas market pressure led to a significant cost reduction in the domestic market. The cost of the plastics other than PET bottles remained high.
Sorting
When the PET bottles are returned to an authorized redemption center, or to the original seller in some jurisdictions, the deposit is partly or fully refunded to the redeemer. In both cases the collected post-consumer PET is taken to recycling centres known as materials recovery facilities (MRF) where it is sorted and separated from other materials such as metal, objects made out of other rigid plastics such as PVC, HDPE, polypropylene, flexible plastics such as those used for bags (generally low density polyethylene), drink cartons, glass, and anything else which is not made out of PET.
Post-consumer PET is often sorted into different colour fractions: transparent or uncoloured PET, blue and green coloured PET, and the remainder into a mixed colours fraction. The emergence of new colours (such as amber for plastic beer bottles) further complicates the sorting process for the recycling industry.
Processing for sale
The sorted post-consumer PET waste is crushed, pressed into bales and offered for sale to recycling companies. Colourless/light blue post-consumer PET attracts higher sales prices than the darker blue and green fractions. The mixed color fraction is the least valuable.
Further treatment
The further treatment process includes crushing, washing, separating and drying. Recycling companies further treat the post-consumer PET by shredding the material into small fragments. These fragments still contain residues of the original content, shredded paper labels and plastic caps. These are removed by different processes, resulting in pure PET fragments, or “PET flakes”. PET flakes are used as the raw material for a range of products that would otherwise be made of polyester. Examples include polyester fibres (a base material for the production of clothing, pillows, carpets, etc.), polyester sheets, strapping, or back into PET bottles.