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Pp water cup safe?
- Aug 10, 2018 -

1. Safety, PP cup is an environmentally friendly material, he can reach the food grade. This is non-toxic, PP plastic - polypropylene, please choose the number 5 in the triangle, in order to effectively withstand high temperatures. The highest melting point is 167 ° C. There is no problem with boiling water.

2, pp material

(1) Polypropylene is a thermoplastic resin obtained by polymerizing propylene. According to the position of the methyl group, it is classified into three types: isotactic polypropylene, atactic polypropylene, and syndiotactic polypropylene.

(2) The methyl group is arranged on the same side of the main chain of the molecule as isotactic polypropylene. If the methyl groups are disorderly arranged on both sides of the molecular main chain, it is called atactic polypropylene, and when the methyl groups are alternately arranged in the molecular main chain, The side is called syndiotactic polypropylene. In general industrial production of polypropylene resin, the isotactic structure content is about 95%, and the rest is random or syndiotactic polypropylene. Industrial products are based on isotactic substances. Polypropylene also includes copolymers of propylene and a small amount of ethylene. Usually a translucent, colorless solid, odorless and non-toxic.

(3) The melting point can be as high as 167 ° C due to the high degree of crystallisation due to structural regularity. Heat-resistant, corrosion-resistant, steam-sterilizable products are its outstanding advantages. The low density is the lightest general purpose plastic. The disadvantage is that it is poor in low temperature impact resistance and easy to age, but can be overcome by modification.

(4) The copolymer type PP material has a lower heat distortion temperature (100 ° C), low transparency, low gloss, low rigidity, but has stronger impact strength, and the impact strength of PP increases with the ethylene content. And increase. 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.

(5) The melt mass flow rate (MFR) of PP is usually from 1 to 100. Low MFR PP materials have better impact resistance but lower elongation. For materials of the same MFR, the impact strength of the copolymerization type is higher than that of the homopolymer type. Due to crystallization, the shrinkage rate of PP is quite high, generally 1.6 to 2.0%.