Today is August 29th of 19 years, and soon one month has passed, followed by Jin Jiuyin Shi, and started as a student in September, but as a friend of Dongguan plastic mold industry, it is only a work month. Only. Today, we introduce PP plastic materials in plastic mold injection production.
PP is a semi-crystalline material. It is harder and has a higher melting point than PE. Since the PP temperature of the homopolymer type is very brittle when it is above 0 °C, many commercial PP materials are random copolymers containing 1% to 4% ethylene or a clamp copolymer having a higher ethylene content. The copolymer type PP material has a low heat distortion temperature (100 ° C), low transparency, low gloss, low rigidity, but has a stronger impact strength.
The strength of PP increases as the ethylene content increases. The Vicat softening temperature of PP is 150 °C. Due to the high degree of crystallinity, this material has excellent surface stiffness and scratch resistance. There is no environmental stress cracking problem in PP. Typically, PP is modified by the addition of glass fibers, metal additives or thermoplastic rubber. The flow rate of PP is in the range of 1 to 40. Low MFR PP materials have better impact resistance but lower elongation. For materials of the same MFR, the 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 1.8% to 2.5%. And the direction uniformity of shrinkage is much better than materials such as PE-HD. The addition of 30% glass additive can reduce the shrinkage to 0.7%. Both the homopolymer type and the copolymer type PP materials have excellent moisture absorption resistance, acid and alkali corrosion resistance, and solubility resistance. However, it is not resistant to aromatic hydrocarbons such as benzene solvents, chlorinated hydrocarbons (carbon tetrachloride) solvents, and the like. 
PP plastics are low in cost, easy to form, and tasteless and non-toxic. PP plastics also have a food grade, which is itself a container for food.
Note: The above information from the Jiezheng mold finishing on the Internet, welcome reproduced, indicate the source!