What is engineering plastics?
Engineering plastics refer to the industrial plastics used to make industrial parts or shell materials, which are superior in strength, impact resistance, heat resistance, hardness and aging resistance.Japanese industry defines it as "can be used as structural and mechanical parts with high performance plastic, heat resistance at 100 ℃ above, mainly used in industry", its performance include: 1.Thermal properties: glass transfer temperature (Tg) and melting point (Tm);High thermal deformation temperature (HDT);Long-term high temperature (ul-746b);Large temperature range;The coefficient of thermal expansion is small. 2.Mechanical properties: high strength, high mechanical modulus, low creep, strong wear resistance and fatigue resistance. 3.Others: good chemical resistance, electrical resistance, flame resistance, weather resistance and dimensional stability. Those regarded as universal engineering plastics include polycarbonate (PC), polyamide (nylon), polyacetal (POM), denatured polyphenyl ether (denatured PPE), polyester (PETP, PBTP), polyaryl ester, and thermoplastic unsaturated polyester, phenol plastics, epoxy plastics, etc.Their basic characteristics as the tensile strength are more than 50 mpa, tensile strength in the 500 kg/cm, resistance to impact more than 50 j/m, bending elasticity rate at 24000 kg/cm, crooked load temperature over 100 ℃, excellent hardness, aging.If polypropylene improves its hardness and cold resistance, it can also be included in the scope of engineering plastics.In addition, it also includes fluorinated plastics of low strength, superior resistance to drugs and high resistance to silicon, polyamides, polyimides, Polysufone(PSF), PES, propylene plastics, denatured melamine plastics, BTResin, PEEK, PEI, liquid crystal plastics, etc. The chemical structure of engineering plastics is different, so their characteristics of drug resistance, friction and motor are different.Due to the different molding properties of engineering plastics, some of them are suitable for any molding method, while some of them can only be processed in a certain molding method, which results in the limitation of application.The impact resistance of thermosetting engineering plastics is poor, so glass fiber is usually added.Engineering plastics, in addition to the high impact resistance such as polycarbonate, usually have the properties of hard, brittle and low elongation, but if 20-30% glass fiber is added, its impact resistance will be improved.