Application of PET in various industries

 PET plastic is the abbreviation of English Polyethylene terephthalate, referred to as PET or PETP. Chinese means: polyterephthalate plastics, mainly including polyethylene terephthalate PET and polybutylene terephthalate PBT. Polyethylene terephthalate is also commonly known as polyester resin, commonly known as polyester resin.

 　　PET plastic structure 　　PET plastic has a highly symmetrical molecular structure and a certain crystal orientation ability, so it has high film-forming properties and properties. PET plastic has good optical properties and weather resistance, and amorphous PET plastic has good optical transparency. In addition, PET plastic has excellent wear resistance, friction, dimensional stability and electrical insulation. Bottles made of PET have high strength, good transparency, non-toxic, anti-permeability, light weight, high production efficiency, etc., so they have been widely used. The molecular chain structure of PBT and PET is similar, and most of the properties are the same, except that the main chain of the molecule has changed from two methylene groups to four, so the molecule is more flexible and the processing performance is better.　　PET is a milky white or light yellow highly crystalline polymer with a smooth and shiny surface. Creep resistance, fatigue resistance, good friction resistance and dimensional stability, low abrasion and high hardness, with the largest toughness among thermoplastics; good electrical insulation performance, less affected by temperature, but poor corona resistance. It is non-toxic, weather-resistant, chemical-resistant, low water absorption, resistant to weak acids and organic solvents, but not immersed in hot water or alkali.　　 PET resin has high glass transition temperature, slow crystallization speed, long molding cycle, long molding cycle, large molding shrinkage, poor dimensional stability, brittleness of crystallization molding, low heat resistance, etc.　　Through the improvement of nucleating agent, crystallization agent and glass fiber reinforcement, PET has the following characteristics in addition to the properties of PBT: 　　1. Heat distortion temperature and long-term use temperature are the *highest among thermoplastic general engineering plastics; 　　2. Because of its high heat resistance, the reinforced PET is immersed in a solder bath at 250°C for 10 seconds, and it hardly deforms or discolors. It is especially suitable for the preparation of soldered electronic and electrical parts; 　　3. The bending strength is 200MPa, the elastic modulus is 4000MPa, the creep and fatigue resistance is also very good, the surface hardness is high, and the mechanical properties are similar to those of thermosetting plastics; 　　4. Since the ethylene glycol used in the production of PET is almost half the price of the butylene glycol used in the production of PBT, the price of PET resin and reinforced PET is the lowest among engineering plastics, and has a very high cost performance.

Edit this paragraph of the development history of PET plastics

　　 In 1946, the United Kingdom published the first preparation of PET. In 1949, British ICI Company completed the pilot test, but after the United States DuPont purchased the ******, the production facility was established in 1953, the first in the world to realize industrialized production. In the early days, almost all PET was used for synthetic fibers, commonly known as polyester in our country, which is indeed good. Since the 1980s, PET has made breakthroughs as engineering plastics, and nucleating agents and crystallization accelerators have been successively developed. At present, PET and PBT together as thermoplastic polyesters have become one of the five major engineering plastics.　　 my country's PET production scale lags far behind several major foreign manufacturers. In the 1980s, my country gradually introduced advanced PET resin synthesis equipment from 10,000 tons to hundreds of thousands of tons from abroad, and the quality and output have made considerable progress. According to statistics from the China Textile Institute, in 1997, my country produced 1.74 million tons of PET chip resin, of which the production capacity of high-viscosity packaging chip resin was 224,000 tons, so there are sufficient sources of resin for the production of PET engineering plastics. Since the equipment for preparing various blending and modifying PET plastics is common with other polymer blending and modifying devices, domestic compounding extruders and other manufacturing have also formed a certain scale, so as long as the market is opened up, domestic PET plastics The production will also grow rapidly.

Edit the use of PET plastic in this paragraph

　　Glass fiber reinforced PET is suitable for electrical and electronic and automotive industries, and is used in various coil bobbins, transformers, televisions, tape recorder parts and shells, automotive lamp holders, lampshades, incandescent lamp holders, relays, selenium rectifiers, etc. The current consumption ratio of PET engineering plastics in several application fields is: electrical and electronic 26%, automobiles 22%, machinery 19%, appliances 10%, consumer goods 10%, and others 13%. At present, the total consumption of PET engineering plastics is not large, accounting for only 1.6% of the total PET. 1. Film and sheet materials: all kinds of food, medicine, non-toxic and sterile packaging materials; high-end packaging materials for textiles, precision instruments, electrical components; audio tapes, video tapes, movie films, computer floppy disks, metal coatings and photosensitive films Such as substrates; electrical insulating materials, capacitor films, flexible printed circuit boards and membrane switches and other electronic and mechanical fields.　　2. Application of packaging bottles: Its application has been developed from carbonated beverages at the beginning to the present beer bottles, edible oil bottles, condiment bottles, medicine bottles, cosmetic bottles, etc.　　3. Electronic appliances: manufacturing connectors, coil bobbins, integrated circuit shells, capacitor shells, transformer shells, TV accessories, tuners, switches, timer shells, automatic fuses, motor brackets, relays, etc. 4. Auto parts: such as switchboard covers, ignition coils, various valves, exhaust parts, distributor covers, measuring instrument covers, small motor covers, etc. The excellent paintability, surface gloss and rigidity of PET can also be used. Manufacture of exterior parts for automobiles.　　 5. Mechanical equipment: manufacturing gears, cams, pump housings, pulleys, motor frames and clock parts, and can also be used as microwave oven bakeware, various ceilings, outdoor billboards and models, etc. . 　　 6. The molding process of PET plastic can be injection molding, extrusion, blow molding, coating, bonding, machining, electroplating, electroplating, vacuum metal plating, and printing.