Shanghai Daoqin Plastics Co., Ltd.

PP polypropylene (PP) typical applications scope/range
automotive industrial （ main/primary use metal additives PP plastics raw materials : sheet/plate, tube/pipe, and other ）, device 械（洗碗 machine 门衬垫, drying machine tube/pipe, machine frame and machine cover/cap, 冰箱门衬垫 and other ）, day use product （草坪 and equipment 如剪草 machine and water device and other ）.

injection molding process conditions
drying 处理: if 储存适当则不 need drying 处理. temperature degree: 220~275C, attention/notes need ultra- 275C.
mold temperature degree : 40~80C, use 50C. crystallization degree main/primary mold temperature degree 决定. injection pressure: can large to 1800bar.
injection speed degree : usually, use high speed injection molding can make internal pressure decrease small to most small. if products surface defect, that use relatively high temperature degree lower low speed injection molding.
runner and gate : for/regarding cold runner, type runner scope/range is 4~7mm. use is 圆形 注入口 and runner. has type type gate can use. type gate scope/range is 1~1.5mm, can use small to 0.7mm gate. for/regarding gate, most small gate deep degree is thick semi; most small gate wide degree less is thick 两倍. PP材 material full can use hot runner system.

chemical and material features
PP is types semi crystallization property material. it ratio PE need more hard and has more high melting point. due to homopolymer type PP temperature degree high 于0C above non therefore many PP材 material is add 入1~4% ethylene random copolymer or more high ratio rate ethylene content 钳段式 copolymer. poly material type PP材 material has relatively low hot temperature degree （100C）, low transparent degree, low gloss degree, low rigid property, is has has more strong/high impact resistant strong/high degree. PP strong/high degree ethylene content increase increase large. PP Vicat softening temperature is 150C. due to crystallization degree relatively high, this type of material surface rigid degree and resistant features very good. PP不存 in ring force cracking issues. usually, using/adopting add glass fiber, metal additives or thermoplastic methods for PP进行 modified. PP flow rate MFR scope/range in 1~40. low MFR PP材 material impact resistant features relatively good 但延展 strong/high degree relatively low. for/regarding same MFR material, copolymer type strong/high degree ratio homopolymer type need high. due to crystallization, PP shrinkage rate versus high, generally is 1.8~2.5%. and shrinkage rate direction uniform property ratio PE-HD and other material need good more. add 入30% 玻璃 additives can make shrinkage rate drop to 0.7%. homopolymer type and copolymer type PP材 material tool has excellent resistant wet property, resistant acid alkali property, resistant solvent understanding property. however, it for 芳香烃（如苯） solvent agent, chlorine 化烃（四 chlorine carbon ） solvent agent and other has resistant force. PP也不象PE that in high temperature lower still tool has resistant oxidation property.