General plastics generally refer to the plastics with large output, wide use, good formability and low price, such as polyethylene, polypropylene, phenolic, etc. There are five kinds of general plastics, namely polyethylene, polypropylene, PVC, polystyrene and ABS. They are all thermoplastics. Polyethylene (PE) is a variety with high output in the plastic industry. Polyethylene is an opaque or translucent crystalline plastic with light weight. It has excellent low temperature resistance (the low service temperature of zui can reach - 70~- 100 ℃), good electrical insulation and chemical stability, and can withstand the corrosion of most acids and alkalis, but it is not heat-resistant. Polyethylene is suitable for processing by injection molding, blow molding, extrusion and other methods. PE can be divided into low-density polyethylene (LDPE) according to different densities; High density polyethylene (HDPE); LLDPE. Polypropylene (PP) Polypropylene is a thermoplastic plastic polymerized from propylene. It is usually a colorless, translucent solid, odorless and non-toxic, with a density of 0.90~0.919 g/cm. It is a light zui general-purpose plastic. Its outstanding advantages are that it has the characteristics of resistance to cooking in water, corrosion resistance, strength, rigidity and transparency are better than polyethylene, but its disadvantages are poor low-temperature impact resistance and easy aging, However, it can be improved by modifying and adding additives respectively. Polypropylene can be produced by slurry method, liquid phase bulk method and gas phase method. Polyvinyl chloride (PVC) Polyvinyl chloride (PVC) is a plastic polymerized by vinyl chloride. Its hardness can be greatly changed by adding plasticizer. Its hard products and even soft products are widely used. The production methods of PVC include suspension polymerization, lotion polymerization and bulk polymerization, with suspension polymerization as the main method. Polystyrene (PS) General polystyrene is a polymer of styrene, with transparent appearance, but has the disadvantage of brittleness. Therefore, impact resistant polystyrene (HTPS) can be made by adding polybutadiene. The main production methods of polystyrene include bulk polymerization, suspension polymerization and solution polymerization. ABS resin is the product of the copolymerization of acrylonitrile butadiene styrene monomers, which is referred to as ABS terpolymer. Due to the different proportions of components A (acrylonitrile), B (butadiene) and S (styrene) in the composition and different manufacturing methods, the properties of this kind of plastic are also very different. ABS is suitable for injection molding and extrusion processing, so its purpose is mainly to produce these two types of products.

Engineering plastics refer to a class of high-performance polymer materials that can be used as structural materials, withstand mechanical stress in a wide temperature range, and are used in a more demanding chemical and physical environment- General refers to the plastic that can withstand certain external forces, has good mechanical properties and dimensional stability, and can maintain its excellent performance at high and low temperatures, and can be used as engineering structural parts. Such as ABS, nylon, alum, etc. Those used as general-purpose plastics include polycarbonate (PC), polyamide (PA), polyacetal (POM), modified polyphenylene oxide (PPE), polyester (PETP, PBTP), polyphenylene sulfide (PPS), polyaryl ester, while thermosetting plastics include unsaturated polyester, phenol plastic, epoxy plastic, etc. The tensile strength is more than 50MPa, the tensile strength is more than 500kg/cm2, the impact resistance is more than 50J/m, the bending elasticity is 24000kg/cm2, the load deflection temperature is more than 100 ℃, and the hardness and aging property are excellent. Polypropylene can also be included in the scope of engineering plastics if it improves hardness and cold resistance. In addition, the special ones are fluorine plastics with weak strength, high heat resistance and drug resistance, and silicon melt compounds, polyamides, polyimide, polybismaleimide, Polysufone (PSF), PES, propylene plastics, modified melamine plastics, BT Resin, PEEK, PEI, liquid crystal plastics, etc. with high heat resistance. Due to different chemical structures, there are also some differences in drug resistance, friction characteristics, motor characteristics, etc. Moreover, due to different formability, there are those applicable to any forming method, and there are also those who can only process in a certain forming method, resulting in limited application. The impact resistance of thermosetting engineering plastics is poor, so glass fibers are mostly added. In addition to polycarbonate and other materials with high impact resistance, engineering plastics usually have small elongation, hard and brittle properties. However, if 20-30% glass fiber is added, it can be improved. The application of five major engineering plastics Polyamide (PA) has won people's attention because of its unique low specific gravity, high tensile strength, wear resistance, good self-lubricating property, excellent impact toughness, and both rigid and flexible properties. In addition, it is easy to process, high efficiency, and light specific gravity (only 1/7 of gold). It can be processed into various products to replace metal, and is widely used in automobile and transportation industries. Typical products include pump impellers, fan blades, valve seats, bushings, bearings, various instrument panels, automotive electrical instruments, cold and hot air control valves and other parts. About 3.6~4kg nylon products are consumed per vehicle. The consumption proportion of polyamide in automobile industry is large, followed by electronic and electrical industry. Polycarbonate (PC) not only has the strength similar to that of non-ferrous metals, but also has ductility and strong toughness. Its impact strength is extremely high, and it can withstand the explosion of TV fluorescent screen without being damaged by hammering. Polycarbonate has excellent transparency and can be applied with any color. Due to the above excellent performance of polycarbonate, it has been widely used in various safety lampshades, signal lamps, transparent protective plates of gymnasiums and stadiums, lighting glass, glass of high-rise buildings, automobile mirrors, windshield plates, aircraft cockpit glass, and motorcycle helmets. 

The market where Zui is used most is computers, office equipment, automobiles, alternative glass and sheets. CD and DVD discs are one of the potential markets of Zui. Polyoxymethylene (POM) is known as "super steel" because of its superior mechanical and chemical properties. Therefore, it can be used as a material that many metal and non-metallic materials are not competent for. It is mainly used as small module gears with high precision, instrument precision parts with complex geometry, tap water and gas explosion pipeline valves. In China, the use of POM in agricultural sprinkler irrigation machinery can save a lot of copper materials. Polybutylene terephthalate (PBT) is a thermoplastic polyester. Compared with other thermoplastic engineering plastics, the unreinforced PBT has better processability and electrical properties. The glass transition temperature of PBT is low. When the mold temperature is 50 ℃, it can crystallize rapidly, and the processing cycle is short. Polybutylene terephthalate (PBT) is widely used in electronic, electrical and automotive industries. Because of its high insulation and temperature resistance, PBT can be used as the return transformer of TV, automobile distributor and ignition coil, office equipment shell and base, various automobile exterior parts, air conditioner fan, electronic stove base, and office equipment shell. Polyphenylene oxide (PPO) resin has excellent physical and mechanical properties, heat resistance and electrical insulation, low moisture absorption, high strength, good dimensional stability, and creep resistance at high temperatures is excellent among all thermoplastic engineering plastics. It can be applied to small household appliances such as washing machine compressor cover, vacuum cleaner case, coffee appliance, hair styling device, massager, microwave oven ware, etc. The modified polyphenylene oxide is also used for TV components, connectors of telex terminal equipment, etc.