Recycling of the Plastic Polymers
Due to the increased need and benefits of reusing the waste polymer in the modified manner the process of recycling polymers has been increased. For plastic/polymer recycling there is often a need to identify which particular plastic material has been used for a given product. We can recognize the types of plastics by the numerical coding system created by the Society of the Plastics Industry. There are six different types of plastic resins that are commonly used to package household products. The identification codes listed below can be found on the bottom of most plastic packaging.
- PETE Polyethylene Terephthalate (PET) – Soda & water containers, some waterproof packaging. Recycling PET is similar to the polyethylenes (PE). Bottles may be color sorted and are ground up and washed. Unlike polyethylene, PET sinks in the wash water while the plastic caps and labels are floated off. The clean flake is dried and often repelletized.
- HDPE High-Density Polyethylene – Milk, detergent & oil bottles, Toys and plastic bags. HDPE is called natural since that is it’s natural color, and it is the most valuable because it can be made into any color when it is recycled.
- V Vinyl/Polyvinyl Chloride (PVC) – Food wrap, vegetable oil bottles, blister packages.
- LDPE Low-Density Polyethylene – Many plastic bags. Shrink wrap, garment bags. It ic chemically similar to HDPE but it is less dense and more flexible. Most polyethylene film is made from LDPE which you often see as plastic bags and grocery sacks.
- PP Polypropylene – Refrigerated containers, some bags, most bottle tops, some carpets, some food wrap.
- PS Polystyrene – Throwaway utensils, meat packing, protective packing.
There are five factors that are necessary in order to recycle the plastic successfully
- The supply of used plastic has to be of a large quantity.
- This large quantity of plastic is collected at certain areas.
- Once the plastic is collected, the sorting and separating process begins; this is the third step in the process.
- The sorting and separating process depends upon the type of polymers that make up the plastic.
- The reprocessing of polymers includes the melting process, the melting process can be accomplished if the polymers have not been widely cross-linked with any synthetics. If the cross-linking of polymers contain too many synthetics, the polymers will be difficult to stretch and less pliable.
- The final step is the manufacturing of the melted plastic into new products.