What material does pp represent in plastics
pp stands for polypropylene material in plastics. Polypropylene is a kind of thermoplastic resin made by polymerization of propylene.
Copolymer PP material has a lower bai heat distortion temperature (100℃), low transparency, low gloss, low rigidity, but has stronger impact strength. The impact strength of PP increases with the increase of ethylene content. Big. The Vicat softening temperature of PP is 150°C. Due to the high crystallinity, the surface stiffness and scratch resistance of this material are very good. PP does not have the problem of environmental stress cracking.
The melt mass flow rate (MFR) of PP is usually 1-100. PP materials with low MFR have better impact resistance but lower tensile strength. For the same MFR material, the impact strength of the copolymer type is higher than that of the homopolymer type. Due to crystallization, the shrinkage rate of PP is quite high, generally 1.6~2.0%.
