Shanghai Daoqin Plastics Co., Ltd.

　　二次 injection molding and injection molding, di injection molding and injection molding 一样, belongs to more material injection molding technology. more material injection molding basic is will 2 types or multiple different features material combined in 一起, from improve/increase product value. in in, types 注入材 material is or 者基底材 material, types 注入材 material is cover/cap material.

　　 various injection molding technology

　　 in injection molding process in, cover/cap material 注入基材 upper 方, lower 方, or internal, combined formed is 一 完整 部 parts. this process can through more injection molding or injection molding formed. usually use cover/cap material is elastic property resin.

　　 more injection molding: if cover/cap material 构造允许 话, more injection molding is types very good medical devices processing methods. technology need has more machine 筒 特殊 injection molding machine, will different resin 注入一 injection molding mold. machine 筒应并排 or 呈L type 放置, or more 注入点 will resin mold. use 同一 注入点时, is 共塑, production composite/compounding parts is by outer 层包覆 core resin material. use more 注入点时, is injection molding, types material in types material upper molding, generate more structure.

　　但 is more injection molding suitable for has product. injection molding 时, must slip block or will 模芯移至另一 mold cavity, also has methods is will 模芯送入另一台 injection molding machine.

　　嵌入 injection molding: need production full cover/cap injection molding this category of product, need use injection molding. is to full cover/cap, 基材必 must from mold cavity in 移出, 放入另一 模芯 and mold cavity, 以便注入覆 cover/cap material. in process in, mold meanwhile in 同一台 or 另一台 different dimensions injection molding machine （取决于 injection molding parts large small ） upper 运转. usually need ratio cover/cap material large more, and can can need preheating, make surface temperature degree 接近覆 cover/cap material melting point, from obtain most bonding strong/high degree.

　　模 inner 组装

　　二次 injection molding has by is inner 组装, is types material most rear full combined in 一起, not only is generate delamination structure, tube/pipe is mono parts or is parts material, can using/adopting technology. application is 何, ensure and cover/cap material to machine or chemical bonding strong/high degree is important.

　　 more material injection molding precautions

　　 generally 说, need strong/high bonding degree, cover/cap material resin temperature degree and same. if cover/cap material temperature degree low, method 熔化基材 surface, between bonding 则不够坚 solid. or temperature degree high, 基材就会 soft deformation, heavy 时, cover/cap material 会穿透基材, 导致部 parts processing 失败. therefore, selection 匹配 材 material can ensure good bonding. generally 而言, 匹配材 material tool has versus chemical features or has composite/compounding formed separation. and cover/cap material 不匹配时, usually can formed machine 械联锁 function, non chemical bonding.

　　 more material injection molding also attention/notes issues, most Common 包括: polymer between chemical or machine bonding strong/high degree 不够, mono or more parts material filling full, and mono or more material parts flash/burrs 闪蒸.

　　 injection molding machine maintain injection molding property. in addition, injection molding machine material 筒 射 amount and injection molding parts dimensions ratio value is effect/influence injection molding quality important factors. ratio value for/regarding has injection molding as separation key/critical, in injection molding in is important. plant/unit can water separation cover/cap material, injection molding material is metal 时止逆 plant/unit as relatively easy, is metal and relatively is has elastic property plastics, plant/unit as comparison difficult.

　　材 material selection

　　二次 injection molding resin material selection has multiple factors, 一方面 need 取决于基材 features, 另一方面则取决于 application property can. specific 说, has below/following 几点:

　　· chemical resistant property （符 combined and other as requirements ）.

　　· flame retardant property （符 combined environmental protection and other requirements ）. environmental protection is table/sheet product combined ring and standards 标志.

　　· wear resistant degree （以免凹陷 or 脱落）.

　　· hardness （符 combined or other requirements ）.

　　· medical specification （ FDA, USP Class VI, ISO10993 and material versus property requirements ）.

　　· types type （蒸汽, 伽玛射线 and other ）.

　　· resistant impact property （符 combined structure requirements ）.

　　· melting point （符 combined application temperature degree requirements, soft or deformation ）.

　　· bonding methods （两 types material 不匹配时形 formed machine 械联锁 function, types material 匹配时形 formed chemical bonding ）.

　　 in 5-8 year 间, cover/cap material has very large development, already R&D multiple elastic property resin. ratio 如, thermoplastic property poly ester (TPU), styrene - ethylene /丁烯- styrene polymer (SEBS), copolymer ester, polyamide (PA), thermoplastic 橡胶(TPR)以 and thermoplastic 硫化橡胶(TPV). application in, generally selection and polypropylene (PP) bonding degree relatively good new type polypropylene (PP) type resin.

　　 this material hardness very large. generally 而言, material hardness high, wear resistant property strong/high. material 纹理也会 effect/influence hardness. due to in resistant property testing in, wear resistant property relatively strong/high material loss relatively less, 例如, 进行旋 pressure testing 时, hardness large resin abrasion loss need less, application selection wear resistant property can strong/high material.

　　SEBS resin hardness very low, to Shore A 30, TPU resin hardness is Shore A 60, and soft hardness more., generally through add increase agent or material reduce hardness. is, this additives in or use 时会析出（ or is 霜化）, combined medical application requirements.

　　 due to injection molding resin material development, selection scope/range day 益广泛, currently already 包括: acrylonitrile butadiene styrene, polycarbonate (PC) and nylon. material scope/range expand large is design provide more more 空间. new type material application belt/tape new issues, 例如: material bonding, parts design and mold as and other and other.

　　 process design precautions

　　 in injection molding process design in, plant/unit, 射嘴孔, 出风口以 and mold surface is key/critical elements.

　　基材 and cover/cap material between plant/unit for/regarding bonding 效果极 is key/critical, 应避免 let injection shot cover/cap material 逐渐变 thin or flash/burrs. cover/cap material thin, 会导致 bonding 不牢, and 卷边. good plant/unit design will cover/cap material and obvious 隔开. 射嘴孔 design for/regarding injection molding formed 功同样 important. runner long degree and thick ratio value is effect/influence bonding main/primary factors. according to experience, ratio value ultra- 150:1, development new process design ratio value maintain in 80:1 left right.

　　 is amount shrink short process/workflow, 射嘴孔应设置 in thick most large 位置. use TPE resin 时, need attention/notes 射嘴孔径 large small. TPU and other material need large 口径射嘴, 以适应 relatively high viscosity, anti 止剪切 force high 而发生材 material degradation. SEBS and other material need relatively high speed degree obtain most 佳 流 speed. relatively good method is in most stage/phase use small 口径射嘴, 初次采样 rear again adjustment large small.

　　 and 射嘴孔一样, 出风口也 is effect/influence bonding important factors, how to control gas amount is large difficult 题, if control good, can can bonding 不牢, flash/burrs phenomenon. 出风口 deep degree for/regarding anti flash/burrs is key/critical, according to cover/cap material viscosity different, 出风口 deep degree in 0.0005-0.001英寸 between.

　　 for/regarding certain parts design, can using/adopting decoration property surface 纹理, 以便于 products ejection. large more 数TPE材 material easy viscous 附于模面, this is is type material tool has metal hydrophilic combined property, or is is in mold opening material and between formed true 空. due to many material in products ejection rear also formed stability chemical bonding, if and viscous 附, 就会极 large effect/influence bonding 效果. this table/sheet parts processing rear must small 心处理, if need bonding testing, need and other 待24 small rear can 进行, 以便材 material can formed stability chemical bonding.

　　当模面 and mold opening direction 平行时, if force 不够, 也会发生 viscous 附. TPU and other material need 5?–6? force. in addition, plating has 助于部 parts ejection.

　　 another, surface design need fine 斟酌. surface 纹理会 effect/influence cover/cap material 柔感, and thick degree. combined 适 壁 thick and surface design can versus versus formed, has obtain processing features. usually, material hardness low soft/flexible. optimization surface can decrease/reduce injection molding 瑕疵, improvement product 手感, upper ratio hardness more is soft/flexible.