Engineering plastics mainly refer to thermoplastics that can be used as structural materials. Engineering plastics have excellent comprehensive properties, high rigidity, low creep, high mechanical strength, good heat resistance, and good electrical insulation. They can be used for a long time in harsh chemical and physical environments and can replace metals as engineering structural materials. Engineering plastics can be divided into general engineering plastics and special engineering plastics. The main varieties of the former are polyamide (PA), polycarbonate (PC), polyoxymethylene (POM), polyphenylene ether (PPO) and polyester (PBT). A PET) pum plastig peirianneg cyffredinol; the latter usually refers to engineering plastics with heat resistance above 150Co, the main varieties are polyphenylene sulfide (PPS), liquid crystal High molecular polymer (LCP), polysulfone (PSF), polyimide (PI), polyaryletherketone (PEEK), polyarylate (PAR), etc.
There is no clear dividing line between engineering plastics and general-purpose plastics. For example, acrylonitrile-butadiene-styrene copolymer (ABS) lies between the two. Its advanced grades can be used as engineering structural materials. The grade is ordinary general-purpose plastics (abroad generally speaking, ABS is classified as general-purpose plastics). For another example, polypropylene (PP) is a typical general-purpose plastic, but after glass fiber reinforcement and other blending, its mechanical strength and heat resistance have been greatly improved, and it can also be used as a structural material in many engineering fields . For another example, polyethylene is also a typical general-purpose plastic, but ultra-high molecular weight polyethylene with a molecular weight of more than 1 million, due to its excellent mechanical properties and high heat distortion temperature, can be widely used as engineering plastics in machinery, transportation, Chemical equipment etc.
There are many kinds of plastics and they are widely used. About 90% of the commonly used resin raw materials are polyethylene PE, polypropylene PP, polyvinyl chloride PVC, polystyrene PS and ABS resin. Fodd bynnag, mae gan bob plastig ei gyfyngiadau.
In the past few decades, people have been committed to the development of new polymer materials. Among the thousands of newly developed polymer materials, few have large-scale applications. Felly, ni allwn obeithio datblygu rhai newydd. Deunyddiau polymer i wella perfformiad. However, it has become a natural choice to process plastics by filling, blending, and reinforcing methods to enhance their flame retardancy, strength, and impact resistance.
Since the beginning of the 21st century, with the development of my country's macro economy, the market capacity of modified plastics has further expanded. The apparent consumption of modified plastics in my country has continued to increase from 720,000 tons in early 2000 to 7.89 million tons in 2013. The compound growth rate is as high as 18.6%, and the home appliance and automobile industries account for a relatively high proportion o geisiadau i lawr yr afon.