Shanghai Daoqin Plastics Co., Ltd.

PET化 Scientific Names is terephthalic acid alcohol ester, also polyester. currently in in use most more is GF-PET. PET in melt lower property relatively good, pressure for viscosity effect/influence ratio temperature degree need large, therefore, main/primary from pressure 手 改变 melt flow property. 1, plastics due to PET large separation in has 脂基, tool has hydrophilic water property, material in high temperature lower for water comparison 敏感, water content ultra- 极限时, in processing in PET molecular weight decline, products belt/tape color, 变脆. 困此, in processing front must for material material drying, its drying temperature degree is 150℃, 4 small above, generally is 170℃, 3-4 small 时. can use method 检验材 material is full drying. recycling material ratio/proportion generally need ultra- 25%, need recycling material drying. 2, injection molding parts machine selection PET due to in melting point rear stability time short, melting point also relatively high, therefore selection temperature relatively more, 塑化时自摩 scratch hot less injection system, and products （含 water material ）实际 weight can small machine injection amount 2/3. this requirements, 华美达近 year development in small series PET specialized system. clamping force large 于6300t/m2 selection. 3, injection molding parts mold and gate design PET bottle generally use hot runner injection molding parts mold molding, injection molding parts mold and injection molding parts machine sheet/plate between most good need has thermal insulation sheet/plate, its thick degree is 12mm left right, thermal insulation sheet/plate can high pressure. gas must 充足, 以免出现 local hot or 碎裂, its gas deep degree generally need ultra- 0.03mm, 否则容 easy generate flash. 4, temperature degree can use method amount degree. 270-295℃不 and other, reinforced grade GF-PET can is 290-315℃ and other. 5, injection speed degree generally injection speed degree need fast, can anti injection 时 早凝 solid. fast, rate high make material material easy 碎. material usually in 4秒 inner formed. 6, back pressure low good, abrasion loss. generally ultra- 100bar. usually must use. 7, time use long time, anti molecular weight decline. amount 避免300℃ above temperature degree. machine less 于15 separation 钟. must as 空射处理; ultra- 15 separation 钟, need use viscosity PE清洁, machine temperature degree drop 至PE temperature degree, again machine is 止. 8, precautions ⑴ recycling material can large, easy generate in lower material 处"架桥"而 effect/influence 塑化. ⑵ if mold temperature control good or material temperature control 不当, easy generate "白雾"而不 transparent. mold temperature low uniform, cooling speed degree fast, crystallization less products transparent.