Plastic products bring convenience and beauty, but also endless troubles. Especially with the rapid development of express delivery and take-away catering, people exclaimed “garbage besieged city” and “white pollution”, and some even said that “plastic is the worst invention of mankind”. The annual output of plastic products in China is nearly 90 million tons.
Waste plastics are landfilled with landfills, which not only take up a lot of space, but also have a long natural degradation time of plastic materials, which affects the sustainable use of land; if it is burned, it will produce a lot of toxic gases.
Plastics come from oil and coal, and waste plastics are the second deposit of mankind, the treasure in the city. The recycling and recycling of waste plastics can alleviate the shortage of crude oil resources in China to a certain extent, and play a positive role in promoting the development of energy conservation, emission reduction and recycling economy.
In order to meet the needs of protecting the global environment, the world’s plastics processing industry has developed many new environmental technologies. In terms of resource conservation, it mainly improves the product’s ageing performance, prolongs life, multi-functionality, and appropriate product design. In terms of resource recycling, it mainly studies high-efficiency sorting of plastic waste, separation technology, high-efficiency melt recycling technology, Chemical recycling technology, fully biodegradable materials, water-soluble materials, edible films; in the reduction technology, mainly research on waste plastic compression and volume reduction technology, film bag container technology, under the premise of ensuring application performance, try to Thinning technology; in the development of CFC substitutes, mainly research on carbon dioxide foaming technology; in the research of alternatives, mainly to develop PVC and PVDC substitutes.
In the treatment of urban plastic solid waste, three methods of landfill, incineration and recycling are currently used. Due to different national conditions, countries vary. The United States is mainly landfill, and Europe and Japan are mainly based on incineration. Due to the landfill treatment, the plastic products are generally light and not easy to rot, which will result in the landfill becoming a soft foundation and will be difficult to use in the future. Incineration treatment, because of the large amount of heat generated by plastics, easy to damage the furnace, plus the gas generated after incineration will promote the warming of the earth, some plastics will also release harmful gases when incinerating and pollute the atmosphere. Adopting the method of recycling and reuse, due to labor consumption, high recycling cost, and lack of corresponding recycling channels, the world recycling and recycling only accounts for about 15% of the total plastic consumption.
Due to the limited world oil resources, recycling of plastics is of great significance from the perspective of saving the earth’s resources. To this end, all countries in the world have invested a lot of manpower and material resources to develop various key technologies for the recycling of waste plastics, and are working to reduce the cost of recycling and recycling plastics.