1. Simple regeneration technology
The simple recycling technology of waste plastic resources refers to the direct processing of waste plastics into new plastic products through the methods of sorting, cleaning, crushing, drying, melting, wire drawing and granulation without modification treatment. In the early stage of the development of the waste plastic recycling industry, there were many applications of simple regeneration technologies. For example, according to certain standards, the recycled waste flexible polyurethane foams were crushed to be used as carpet linings or buffer fillers in packaging, or recycled waste polychlorinated Vinyl products are used for building wire protection pipes after crushing.
The simple recycling technology of waste plastic resources has the advantages of simple production process, less capital investment and lower cost, and the produced plastic products have a wide range of applications. However, the mechanical properties of the raw materials produced by the simple regeneration process have declined, and they are not suitable for the manufacture of high-grade plastic products.
2. Modified regeneration technology
Physical modification generally refers to the use of mechanical blending to modify recycled plastic raw materials with other additives or polymers to optimize and improve the mechanical properties of recycled plastic products, so as to be used in the manufacture of high-grade plastic recycled products. For example, adding fillers to recycled materials can improve the properties of waste plastics, improve the heat resistance of recycled plastic products, and increase the shrinkage of products. Add synthetic fibers, glass fibers and natural fibers to recycled raw materials to improve the modulus and strength of products to expand the use of recycled plastic waste products.
The chemical modification method can broaden the scope of use of recycled plastics and enhance the utilization value of recycled plastic products. The chemical modification methods mainly include cross-linking modification (that is, the polyolefin screened out of waste plastics can improve the heat resistance, dimensional stability, stretchability, environmental resistance, Chemical stability, wear resistance, etc.), chlorination modification (chlorination of waste polyolefin resins to prepare chlorinated polyolefins with different chlorine content), graft copolymerization modification (using a certain grafting method, The graft copolymerization modification of waste polypropylene by grafting monomer).
It greatly shortens the production cycle of recycled plastic products and improves the overall performance of the product.
3. Gasification utilization technology
The gasification method is a relatively simple method of recycling waste plastics. The resulting gasification and degasification products can not only be used for heating and power generation in low-pollution, high-efficiency combined cycle power plants, but also can be used as raw materials to prepare For chemically processed commodities with excellent performance, waste plastics as raw materials for gasification do not need to be sorted and sorted, and are suitable for waste plastic waste treatment with difficult sorting.
Gasification technology has high gasification efficiency in treating waste plastics, and can control the high-temperature gasification temperature and other methods to inhibit the production of the highly toxic fat-soluble substance digallium.
4. Thermal cracking technology
Thermal cracking technology refers to placing the waste plastic that cannot be decomposed in the reactor, and continuously heating it to the decomposition temperature of the waste plastic, so that it is decomposed, absorbed and purified in the reactor, and then the usable decomposition product is obtained. The temperature difference of different decomposition products during the thermal cracking of waste plastics, adopt the method of staged thermal cracking, control the temperature of thermal cracking, and recover the decomposition products of different components.
Different types of waste plastics have different thermal cracking temperatures. For common waste plastics such as polyethylene ladder, polystyrene, polyvinyl chloride and polypropylene, the recycling method of segmental cracking is generally adopted.