1.  Disposal of waste plastics In the treatment of urban plastic solid wastes, three methods are currently used: landfill, incineration, and recycling. Due to different national conditions, different countries have different landfills in the United States, and incineration in Europe and Japan. 1. Landfill treatment, because the quality of plastic is generally light and not easy to rot, it will cause the landfill to become a soft base and it will be difficult to use in the future. 2. Incineration treatment, due to the large amount of heat generated by plastics, easy to damage the furnace, and the gas generated after incineration will promote global warming, and some plastics will release harmful gases during pollution and pollute the atmosphere. 3. Adopt the method of recycling and reuse. Due to labor-consuming, high recycling cost, and lack of corresponding recycling channels, the current recycling in the world accounts for only about 15% of all plastic consumption. However, due to the limited world oil resources, from the perspective of saving the earth’s resources, the recycling of plastics is of great significance. To this end, countries around the world have invested a lot of manpower and material resources to develop key technologies for the recycling of various waste plastics, and are committed to reducing the cost of plastic recycling to develop their suitable application fields.

2. Waste plastic recycling methods The current waste plastic recycling methods are as follows: 1. Heat energy recovery method Most plastics are mainly composed of hydrocarbons and can be burned. For example, polystyrene burns more heat than dye oil. However, heat energy recovery is one of the last methods of waste plastic recycling, because waste plastics burn, most of them will produce toxic gases, which is also a threat to the environment. The burning of halogen-containing plastics will become the culprit of dioxins. 2. Physical recycling and regeneration Physical recycling and regeneration is a method actively promoted and promoted at present, and it is an effective means of turning waste into treasure, energy saving and environmental protection. But at present, it is mainly trapped in the recycling and sorting process. The recycling income is small, the sorting is difficult, and the cost is high. People's awareness of environmental protection is not very high, and garbage cannot be effectively classified. 3. Chemical reduction method This method is to cut the long chain of the polymer to restore its original properties, and the cracked raw materials can be used to make new plastics. Some methods are to add chemical elements to promote the chemical cracking of the combined carbon atoms, or to add energy to promote their thermal cracking. Some materials have been recovered by this method, but most of the materials are still in the experiment. 4. Hydrolysis method This method is used to process mixed plastic articles. According to different plastic components, 60%-80% of the components can be refined into synthetic crude oil. In a joint research report, three chemical companies from BASF, Germany and other countries pointed out that hydrogenation is the best method of thermal cracking, and the synthesized synthetic crude oil has good quality and can be used for oil refining. This treatment method treats halogen-containing waste plastics without producing toxic dioxins and chlorine. With the continuous improvement of this technology, it may become one of the main methods for processing waste plastics in the future.

3. The development direction of environmentally friendly plastics While actively developing plastic recycling technology, it also needs to develop in the direction of favoring disposal or recycling in the manufacture and use of plastics. 1. Reducing design research and development of materials that are suitable for recycling, the focus will not be on which plastic is the most ideal for making individual parts, but on materials that can be widely used, which is a revolutionary change in concept . In order to facilitate recycling, designers began to avoid using a variety of plastics when designing products. BMW of the United States is planning to reduce the type of plastics in its new car design by 40%, with the purpose of facilitating the recycling of waste plastics. The world's electrical and electronic market has attracted attention to the recycling of waste plastics. International Business Machines Corporation (IBM) has begun to mark the plastic parts of computers and business machines, and is developing recyclable plastic electronic parts and simplifying the removal of equipment. The product structure also considers eliminating the surface coloration of the components, controlling the amount of external adhesives used for plastic additives, and reducing the use of recycled process components and extra parts. 2. Biodegradation Research and development of biodegradation has become a research hotspot in the plastic processing industry in countries around the world. The researchers hope to develop a plastic that can degrade in a microbial environment to deal with a large number of single-use plastics, especially the pollution of farmland, mountains and oceans by plastic film and multi-package waste. The research goal is to develop a plastic that can guarantee the use performance of its name during use, and once used up and discarded, it can be decomposed by microorganisms in the environment and thus completely enter the ecological cycle. At the same time, the production cost of this plastic is relatively low and it has corresponding economics. If it is such a biodegradable plastic, it can be composted with ordinary biological waste after use, without having to spend a lot of cost to collect, sort and recycle. Moreover, the decomposition products enter the ecological cycle, which does not cause waste of resources. In the research and development of biodegradable plastics, countries all over the world have invested a lot of financial resources and manpower, and spent a lot of energy on research. The plastics processing industry generally believes that biodegradable plastics is a new technology issue in the 21st century.

4. The rise of the waste plastic recycling industry With the closing of the 19th National Congress of the Communist Party of China, the construction of ecological civilization and ecological environment protection have been deployed as important tasks. The green economy will have unprecedented development opportunities in the next few years. As the amount of waste plastic continues to grow, the waste plastic recycling industry will become an important chapter in the green economy. The national government has already begun to lay out policies, such as domestic waste sorting, recycling site layout, and other formalization of recycling systems, which have introduced policies and started to implement them.