Shanghai Daoqin Plastics Co., Ltd.

        PET plastics injection molding process is plastics processing in non important technology process 之一, for/regarding PET plastics bottle 而言, large more 数情况 lower plastics packaging 厂都会 using/adopting blow molding methods made as processing, injection molding process especially has processing advantages, for/regarding PET injection molding 说, technology need very more factors, lower.

        PET plastics brief introduction: PET化 Scientific Names is terephthalic acid alcohol ester, also polyester. currently in in use most more is GF-PET, main/primary is bottle 胚.

        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.

        PET chemical and material features:PET 玻璃化转化 temperature degree in 165℃ left right, material crystallization temperature degree scope/range is 120~220℃. PET in high temperature lower has very strong/high wet property. for/regarding glass fiber reinforcement type PET材 material 说, in high temperature lower also non easy bending 形变.

         can through add crystallization reinforcement agent improve/increase material crystallization degree. use PET processing transparent products tool has gloss degree and hot temperature degree. can toward PET in add and other additives make bending deformation decrease small to most small. if use relatively low mold temperature degree, that use non filling PET材 material can obtain transparent products.

         injection molding process: injection molding method main/primary used for reinforcement PET molding. usually using/adopting screw injection machine. screw generally 均需进行 hard 化处理, in long use rear abrasion consumption. injection machine nozzle long degree can can short, its 直径应 control in 3mm left right.

         reinforcement PET melting point high 达260℃, is anti nozzle 堵塞, 应安装功 rate relatively large add hot device. another, nozzle 孔 尖端 most good processing formed 如图-1 示 逆锥式, make runner and nozzle inner melt material material can 够方便 切断.

         injection molding machine: injection molding main/primary used for reinforcement PET molding. PET generally lower can selection screw injection molding machine molding.

         most good selection belt/tape has ring type screw, its surface hardness large but also wear resistant loss, long ratio 未L/D=(15～20): 1 pressure shrink ratio is 3: 1.

        L/D太 large material material in material inner time long, degree hot easy degradation, effect/influence products property can. pressure shrink ratio small 剪切生 hot less, easy defect, products property can 差. 反之会 make glass fiber relatively more fracture, force property can decline. processing glass fiber reinforcement PET时, material inner abrasion loss relatively 厉害, material use wear resistant material manufacturing or has wear resistant material.

        喷咀以 short is good, inner requirements abrasion light, requirements can can large. liquid pressure made 动阀门式喷咀 is good. need has temperature and control temperature degree measures ensure 喷咀不会冻结堵塞. is temperature degree can high, 否则造 formed 流涎. molding front must use low pressure PP material, material 筒清洗 dry 净.

        PET main/primary injection molding conditions:

        1, material temperature degree. PET molding temperature degree scope/range narrow, temperature degree high low 会直接 effect/influence products property can. temperature degree low, 则塑化不 good, make parts 出现凹陷, material and other defect;反之, temperature degree high, formed 溢边, nozzle 流涎, color deep, machine strong/high degree decline, 甚至引起 degradation. usually, material temperature degree control in 240~280℃, glass fiber reinforced PET material temperature degree is 250~290℃, ultra- 300℃, nozzle temperature degree generally ratio material temperature degree low 10~20℃.

        2, mold temperature degree. mold temperature effect/influence material cooling speed degree and crystallization degree, crystallization degree different, parts property can different. usually, mold temperature degree control in 100~140℃, molding thin parts 时, can small value; molding thick parts 时, can large value.

        3, injection pressure. PET melt flow property good, easy molding, usually using/adopting in and other pressure, pressure is 80~140MPa, glass fiber reinforced PET injection pressure is 90~150MPa. injection pressure 确定, 应考虑PET viscosity, filler types type and amount, gate and large small, parts and dimensions, mold temperature, injection molding machine type type and other.