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How to define engineering plastics?

Engineering plastics generally refer to the plastic materials which can be used as structural materials to accept mechanical stress and can be used in a wide range of temperature planning and harsh chemical and physical environment.

Engineering plastics can be divided into general engineering plastics and special engineering plastics. General engineering plastics usually refer to five kinds of plastics which have been industrialized and widely used, namely polyamide (nylon, PA), polycarbonate (polycarbonate, PC), Polyoxymethylene (POM), polyester (PBT) and polyphenylene oxide (PPO).

Special engineering plastics refer to some plastics with more excellent functions, but now most of them have no large-scale industrial production plan or have smaller production planning and relatively narrow use, such as polyphenylene sulfide (PPS), polyimide (PI), polysulfone (PSF), polyether ketone (PEK), liquid crystal polymer (LCP), etc.

2. Development of domestic production

Engineering plastics have excellent functions and can replace metal as structural materials. Therefore, they are widely used in the fields of electronic and electrical, transportation, mechanical equipment and daily necessities, and their status in the national economy is increasingly obvious.

The technical development of engineering plastics in China has a history of nearly 40 years. Although it has a certain technical foundation, there is a gap between China and foreign countries in terms of technical level, production ability and output value. There are single types (such as PPO) which are basically vacant.

In terms of business planning, most of the engineering plastics enterprises in our country are thousand tons of production equipment or industrial test equipment, while the annual output of foreign enterprises is more than 10000 tons. The huge difference in planning and process level makes it difficult for domestic engineering plastics to meet the needs of domestic shopping malls, and the function and price of products can not compete with imported products.

Characteristics and uses of three and five general engineering plastics

Polyamide (PA) has won people's attention because of its common low specific gravity, high tensile strength, wear resistance, good self lubrication, excellent impact resistance, and has both rigid and flexible functions. In addition, its processing is simple, high efficiency, light weight (as long as 1 / 7 of metal), it can be processed into various products to replace metal, which is widely used in car and transportation industry. Typical products include pump impeller, fan blade, valve seat, bushing, bearing, various instrument panels, car electrical instruments, cold and hot air control valve and other parts. About 3.6-4 kg nylon products are consumed per car. Polyamide has a large consumption share in the car industry, followed by electronics and electronics.

Although polycarbonate (PC) is a thermoplastic resin, it not only has the strength similar to non-ferrous metals, but also has ductility and strong resistance. It has high impact strength and can not be damaged by hammering. It can withstand the explosion of TV screen.

Polycarbonate has good transparency and can be applied to any color. Due to the above excellent functions of polycarbonate, it has been widely used in various lampshades, signal lights, transparent protective panels of gymnasiums and sports grounds, daylighting glass, high-rise building glass, car mirror, windshield, aircraft cabin glass, motorcycle driving helmet. Shopping malls with large consumption are computers, office equipment, cars, replacement glass and sheet materials.

Polyoxymethylene (POM) is known as "super steel", which is due to its superior mechanical and chemical functions. Therefore, POM can be used as a material that many metal and non-metallic materials can't do. It is mainly used as various small modulus gears with high degree, instruments with disordered geometry, tap water tap and valve of explosion gas pipeline. The use of polyoxymethylene in agricultural sprinkler irrigation machinery in China can save a lot of copper.

Polybutylene terephthalate (PBT) is a kind of thermoplastic polyester. Compared with other thermoplastic engineering plastics, non reinforced PBT has better processing and electrical functions. The glass transition temperature of PBT is low, the mold temperature is 50 ℃, and the crystallization is quick, and the processing cycle is short.

Polybutylene terephthalate (PBT) is widely used in electronic, electrical and car industry. Due to its high margin and temperature resistance, PBT can be used as the scavenging transformer of TV, the distributor and combustion coil of car, the shell and base of office equipment, the external components of various cars, the electromechanical fan of air conditioner, the base of electronic stove and the shell of office equipment.

Polyphenylene oxide (PPO) resin has excellent physical and mechanical functions, heat resistance and electrical edge, low moisture absorption, high strength, good dimensional stability, creep resistance at high temperature is excellent among all thermoplastic engineering plastics. It can be used in washing machine compressor cover, vacuum cleaner shell, coffee utensils, hair styling machine, massager, microwave oven utensils and other small appliances. The modified polyphenylene oxide is also used in TV parts, connectors of telex terminal equipment, etc.

Source: Jiangmen engineering plastics http://www.yun-kang.cn/