PP塑料介绍（PP plastic introduction）.docVIP

PP塑料介绍（PP plastic introduction） PP plastic Polypropylene (PP plastic) is another fine resin variety after nylon. It is a linear polymer with high density, no side chain and high crystallization. It has excellent comprehensive performance. White translucent and waxy when uncolored; Its lighter than polyethylene. It is also more transparent than polyethylene. Chinese name (polypropylene) [1] English name: Polypropylene edit the proportion of PP plastic in this paragraph: 0.9-0.91 g/cubic cm Molding shrinkage: ___________ 0-2.5% Mold temperature 160-220 ℃ Dry conditions Material performance density is small, the strength stiffness and hardness are better than that of low pressure polyethylene heat resistance, can be used in 100 degrees. It has good performance and high frequency insulation is not affected by humidity, but time-varying brittle at low temperature, low wear resistance aging. Suitable for making general machinery parts, corrosion parts and insulation parts edit this paragraph formability ___________ crystalline material, hygroscopicity, prone to melting body burst, long-term contact with the hot metal is easy to decompose. This liquidity is good, but the scope and contraction value is big, prone to shrinkage cavity. Dent, deformation. 3. The cooling speed, gating system and cooling system should slow cooling, and pay attention to control the molding temperature. Low temperature the direction clear direction. Especially when high pressure at low temperature, mold temperature is lower than 50 degrees, the plastic parts is not smooth, easy to cause weld adverse, vestiges of 90 degrees or more prone to buckling deformation _____ the plastic wall thickness shall be uniform and avoid missing glue, sharp corners, to prevent stress concentration. Easy to decompose under certain conditions Common products: basin, barrel, furniture, film, woven bag, bottle caps, bumper, etc. Polypropylene also includes copolymer with propylene and a small amount of ethylene. PP gra