Jul.2023 27
Views: 95
What is engineering plastics
Introduction
Engineering plastics can be divided into two categories :general engineering plastics and special engineering plastics. The former main varieties of polyamide, polycarbonate, polyformaldehyde, modified polyphenylene ether and thermoplastic polyester The latter mainly refers to the heat-resistant up to 150 ℃ above the engineering plastics, the main varieties of polyimide, polyphenylene sulfide, polysulfone, aromatic polyamides, polyarylene esters, polyphenylene esters, polyarylene ether keton
Details
What is engineering plastics
 
Engineering plastics can be used as engineering materials and plastics that replace metal to make machine parts and so on. Engineering plastics have excellent comprehensive performance, rigidity, creep, high mechanical strength, good heat resistance, good electrical insulation, can be used for a long time in the more demanding chemical and physical environment, can replace the metal as a structural engineering materials, but the price is more expensive, the productivity is small.
 
Engineering plastics can be divided into two categories of general engineering plastics and special engineering plastics. 
The former main varieties of polyamide, polycarbonate, polyformaldehyde, modified polyphenylene ether and thermoplastic polyester 
The latter mainly refers to the heat-resistant up to 150 ℃ above the engineering plastics, the main varieties of polyimide, polyphenylene sulfide, polysulfone, aromatic polyamides, polyarylene esters, polyphenylene esters, polyarylene ether ketone, liquid crystal polymers and fluorine resins and so on.
The performance characteristics of engineering plastics are mainly:
(1) Compared with general-purpose plastics, they have excellent heat- and cold-resistant properties, excellent mechanical properties in a wide range of temperatures, and are suitable for use as structural materials;
(2) Good corrosion resistance, less affected by the environment, good durability;
(3) Compared with metal materials, it is easy to process, has high productivity, and can simplify procedures and save costs;
(4) Good dimensional stability and electrical insulation;
(5) Light weight, high specific strength, and outstanding friction and wear resistance.
 
APPLICATIONS
 
Compared with general-purpose plastics, engineering plastics can meet higher requirements in terms of mechanical properties, durability, corrosion resistance, heat resistance, etc., and can be processed more conveniently and can replace metal materials. Engineering plastics are widely used in electrical and electronic, automotive, construction, office equipment, machinery, aerospace and other industries, plastic instead of steel, plastic instead of wood has become an international trend. Engineering plastics has become the world's fastest-growing plastics industry in the field of its development not only on the national pillar industries and modern high-tech industries play a supporting role, but also to promote the transformation of traditional industries and product structure adjustment.
Engineering plastics are increasingly used in automobiles, mainly as bumpers, fuel tanks, instrument panels, body panels, doors, lampshades, fuel pipes, radiators and engine-related parts.
In machinery, engineering plastics can be used for bearings, gears, screws and nuts, seals and other mechanical parts and shells, covers, handwheels, handles, fasteners and pipe fittings and other mechanical structures.
In electrical and electronic appliances, engineering plastics can be used in wire and cable coverings, printed circuit boards, insulating films and other insulating materials and electrical equipment structural components.
In household appliances, engineering plastics can be used in refrigerators, washing machines, air conditioners, television sets, fans, hoovers, irons, microwave ovens, rice cookers, radios, combined audio equipment and lighting appliances.
In the chemical industry, engineering plastics can be used in heat exchangers, chemical equipment lining and other chemical equipment and pipe and pipe fittings, valves, pumps and other chemical pipelines.
Due to the rapid development of China's automotive, electronics and construction industries, China has become the world's fastest growing demand for engineering plastics. According to analysis, with the continuous development of the domestic economy, the demand for engineering plastics will be further growth, the development of China's engineering plastics industry has a very broad prospect. Home appliance industry, only to the refrigerator, freezer, washing machine, air conditioning and various types of small household appliances will reach 600,000 tonnes of engineering plastics demand each year. For communications infrastructure construction and railway, road construction and other aspects of engineering plastics is even more amazing, is expected in the next few years the total demand will reach more than 4.5 million tonnes.
In 2010, China's engineering plastics consumption reached 2.443 million tonnes, up 11% year-on-year, is the world's fastest-growing demand for the country; 2011 China's engineering plastics consumption of 2.72 million tonnes, up 11.34% year-on-year. It is expected that by 2013 China's engineering plastics consumption will reach 3.37 million tonnes, and in 2015 it will reach 4.17 million tonnes.
 
Main varieties Editorial Podcast
 
Engineering plastics mainly include polycarbonate (Polycarbonate, PC), polyamide (Nylon, Polyamide, PA), polyacetal (Polyacetal, Polyoxy Methylene, POM), polyphenylene ether (Polyphenylene Oxide, PPO), polyester (PET, PBT), Polyphenylene Sulfide (PPS), Polyaryl Ester, etc.

Polyamide

Polyamide (PA, common name: nylon) due to the unique low specific gravity, high tensile strength, wear resistance, self-lubricating, excellent impact toughness, with both rigid and flexible performance and win people's attention, coupled with its easy processing, high efficiency, light weight (only 1/7 of the metal), can be processed into a variety of products to replace the metal, is widely used in the automotive and transport industries. Typical products are pump impellers, fan blades, valve seats, bushings, bearings, a variety of instrument panels, automotive electrical instrumentation, hot and cold air conditioning valves and other parts, about each car consumption of nylon products up to 3.6 ~ 4 kg. Polyamide consumption in the automotive industry is the largest proportion, followed by electrical and electronic.

The different purposes of polyamide modification, polyamide modification can be divided into the types of reinforcement, toughening, flame retardant, filling and alloying. Research on nanocomposites of polyamide has also made considerable progress.

In order to obtain polyamide materials with higher strength and heat deflection temperature, inorganic or organic fibres or fillers are added to the polyamide matrix, and high-strength polyamide composites are produced by co-blending and extrusion. Enhanced PA varieties, almost all of the polyamide material can be made to enhance the species.

The main commercial varieties are: enhanced PA6, enhanced PA66, enhanced PA46, enhanced PA1010, enhanced PA610 and so on. The largest production is reinforced PA6 and PA66. commonly used polyamide reinforcing materials are glass fibre, carbon fibre, aramid fibre, inorganic whiskers are also used for polyamide reinforcement.

Polyphenylene sulfide

Abbreviation PPS.

The outstanding properties of PPS are: ① good heat resistance, can be used in the temperature range of 180 ~ 220 ℃; ② corrosion resistance close to PTFE; ③ excellent electrical properties; ④ excellent mechanical properties; ⑤ good flame retardant properties.

PPS shortcomings are: ① price is too high, in the high temperature plastic is low, but much higher than the general engineering plastics; ② poor toughness, brittle; ③ processing viscosity is not stable. Pure PPS is rarely used alone because of the brittle nature, the application of PPS for its modified performance varieties. Specifically: 40% glass fibre reinforced PPS (R4), inorganic filled PPS (R8), carbon fibre reinforced PPS (G6), etc. PPS is used in automobiles accounted for 45% of the electronics, electrical appliances accounted for 30% of the other accounted for 25% of the development of PPS is fast, it is expected to become the sixth largest engineering plastics.

Polycarbonate

Polycarbonate (PC) has a similar strength of non-ferrous metals, while both ductility and toughness, its impact strength is extremely high, with a hammer can not be destroyed, can withstand the explosion of the TV fluorescent screen. Polycarbonate transparency and excellent, and can be applied to any colouring. Because of the above excellent performance of polycarbonate, has been widely used in a variety of safety lampshade, signal lamps, gymnasiums, stadiums, transparent protective panels, lighting glass, high-rise building glass, automobile mirrors, windshield panels, aircraft cockpit glass, motorbike driving helmets. The markets with the largest usage are computers, office equipment, automobiles, replacement glass and sheets, and CD and DVD discs are one of the most promising markets.

Polyoxymethylene

Polyoxymethylene (POM) is a kind of engineering plastics with excellent performance, in foreign countries, it has the name of "steel" and "super steel".POM has the hardness, strength and steeliness similar to that of metal, and it has good self-lubrication, good fatigue resistance, and rich in elasticity in a wide range of temperature and humidity. POM has similar hardness, strength and steel, has good self-lubrication, good fatigue resistance, and rich in elasticity in a wide range of temperature and humidity, in addition to its good chemical resistance, POM is lower than the cost of many other engineering plastics, is replacing some of the traditionally occupied by the metal of the market, such as replacing zinc, brass, aluminium and steel to make a lot of parts, since its inception, POM has been widely used in the field of electrical and electronic, machinery, instrumentation, light industry, automotive, building materials, agriculture and so on. In many new areas of application, such as medical technology, sports equipment, etc., POM also shows good growth.

PBT

Polybutylene terephthalate (PBT) is a thermoplastic polyester, non-reinforced PBT and other thermoplastic engineering plastics, compared with the processing performance and electrical properties of the better.PBT glass transition temperature is low, the mould temperature of 50 ° C can be quickly crystallised, short processing cycle. Polybutylene terephthalate (PBT) is widely used in the electronic, electrical and automotive industries. Due to the high insulation and temperature resistance of PBT, it can be used as the return transformer of TV sets, car distributor and ignition coils, office equipment shells and bases, all kinds of automotive exterior parts, air-conditioner fans, electronic cookers and bases, and office equipment shell parts.

Polyphenylene Ether

Polyphenylene ether

Polyphenylene ether

Abbreviated as PPO, it has excellent comprehensive performance, the biggest feature is that under long-term load, it has excellent dimensional stability and outstanding electrical insulation, and it has a wide range of use temperature, and it can be used for a long time in the range of -127~121℃. Has excellent water resistance, steam resistance, products with high tensile strength and impact strength, creep resistance is also good. In addition, there are good wear resistance and electrical properties. Mainly used instead of stainless steel to manufacture surgical medical equipment. In the electromechanical industry can make gears, blower blades, pipes, valves, screws and other fasteners and connectors, etc., but also for the production of electronic, electrical industry parts, such as coil skeleton and printed circuit boards, etc.