Shanghai Daoqin Plastics Co., Ltd.

precision injection molding parts molding technology precision injection molding parts molding generally is molding made parts degree and surface quality requirements very high process, has is, precision injection molding parts is parts dimensions degree to 0.01～0.001 mm injection molding parts molding process. in recent years,随 electronics, medical, 通讯, automotive and other industry speed development,人们 for plastics products high degree, high property can requirements and day increase,传统 plastics molding process already very difficult meet/satisfy currently high standards requirements, meanwhile, injection molding parts molding is most important plastics molding methods 之一, therefore, precision injection molding parts molding technology 愈 愈受 to heavy 视, make precision injection molding parts molding technology 不断 进步, new technology 不断 涌现. effect/influence precision injection molding parts molding factors precision injection molding parts molding requirements products not only tool has relatively high dimensions degree, relatively low warpage deformation, excellent 良 转写 features, but also also has excellent optical property can and other, therefore, it for injection molding parts machine, injection molding parts injection molding parts mold, molding process, Raw Materials property can and formulation and other has requirements, effect/influence precision injection molding parts molding factors very more. according to currently production 看, effect/influence precision injection molding parts molding factors main/primary has below/following several 方面: （1） plastics shrinkage rate design precision plastics products 时, 应需考虑 plastics shrinkage rate. precision injection molding parts products and other grade can according to SJB72-7.8 in 第1 and 第2两 公差 and other grade 确定. （2） products and dimensions parts and dimensions for made parts degree has very large effect/influence, production table/sheet 明, products 形状越 complex and dimensions large 时, its degree low. （3） injection molding parts mold structure parts degree and injection molding parts mold type 腔数目 and production amount has 关. table/sheet 明, mono type injection molding parts mold structure degree ratio more type injection molding parts mold structure need high, small amount production degree ratio large amount need high. （4） injection molding parts mold processing degree due to injection molding parts products must in mold cavity inner molding, therefore, products degree how to 也不会 ultra- mold cavity degree. usually lower, injection molding parts products degree need ratio injection molding parts mold degree low to 两 公差 and other grade. currently injection molding parts mold manufacturing technology 而言, injection molding parts mold type large separation using/adopting high speed 铣削, abrasion 削, light or electrical processing and other methods manufacturing, this processing methods can to most high degree. （5） injection molding parts machine due to precision injection molding parts molding for products tool has relatively high degree requirements, therefore, it generally need in precision injection molding parts machine upper 进行. precision injection molding parts machine injection molding parts rate need large, control degree need high, liquid pressure system reaction speed degree need fast, clamping system need has rigid property. precision injection molding parts molding plastics selection plastics products molding shrinkage rate relatively large, another, different plastics product types, due to using/adopting polymer and additives types type and its ratio different, it in injection molding parts molding performance flow property can and molding property can will tool has very large 差异;即 make for/regarding separation and ratio full same plastics, due to production injection molding parts processing 家, injection molding parts processing and ring conditions and other factors effect/influence, use it injection molding parts products between also in and dimensions is stability issues. therefore, precision injection molding parts molding plastics remove requirements tool has good flow property can and molding property can outer, also requirements use it molding products can tool has and dimensions stability property. 否则, products degree very difficult ensure. therefore, injection molding parts molding precision plastics products 时, must for plastics product types and its molding property can in 考虑,尽 can can selection shrinkage rate small, long stability property good material. usually, PS, ABS, AS, PMMA, PC, PPO, PSU can molding 3, 4 grade degree products; PA series can molding 4 grade degree products;而POM, PP, PE, TPE and other 不适宜 molding 4 grade above degree products. another, due to machine material filling or glass fiber reinforced plastics shrinkage rate low, dimensional stability high, by use molding high degree products. precision injection molding parts molding process features precision injection molding parts molding process features main/primary is injection pressure high, injection speed degree fast and temperature degree control must 精确. （1） injection pressure high experiment/testing 证明, for/regarding different plastics product types, and dimensions, precision injection molding parts molding pressure is 180—250MPa(普通 injection molding parts use injection pressure generally is 40—200MPa), in certain 特殊情况 lower requirements more high 一. most high 己达450MPa left right. （2） injection speed degree fast injection speed degree large small, not only obvious effect/influence products production rate, more important is can decrease/reduce products dimensions 公差. is improve/increase injection molding parts parts degree, especially for complex products molding, in recent years development speed injection, injection speed degree is 变化, its 变化规律 according to made parts structure and plastics property can 决定. （3） temperature degree control must temperature degree for products molding quality effect/influence very large, is injection molding parts molding large process conditions 之一. for/regarding precision injection molding parts 讲, not only in temperature degree high low issues, but also also in temperature degree control degree issues. very 显然, in precision injection molding parts molding process in, if temperature degree control 不精确, plastics melt flow property and products molding property can and shrinkage rate 就不会 stability, therefore 也就无 method ensure products degree. from this degree 讲, using/adopting precision injection molding parts molding 时, for/regarding machine and nozzle, or is for/regarding injection molding parts injection molding parts mold, must add control it temperature degree scope/range. 例如, precision injection molding parts 时, for machine and nozzle temperature degree using/adopting PID control device, temperature degree scope/range control in 1℃之 inner, for/regarding injection molding parts machine, temperature degree can 达20℃一300℃. precision injection molding parts molding production 时, is ensure products degree, remove must control machine 筒, nozzle and injection molding parts mold temperature degree outer, also need attention/notes demolding rear ring temperature degree for products degree effect/influence. design precision injection molding parts precautions design precision injection molding parts 模时, remove injection molding parts design methods and requirements outer, degree 方面 严格 requirements, also need especially attention/notes lower 面一 事项: 4.1 injection molding parts mold has relatively high design degree injection molding parts mold degree although and processing and assembly technology related, in design has 提出恰当 technology requirements, or injection molding parts mold structure design combined 理, that 么无论 processing and assembly technology more high, injection molding parts mold degree still can to ensure. is ensure precision injection molding parts 模不因 design issues effect/influence degree, attention/notes lower 4点: ①零部 parts design degree and technology requirements and products degree versus need make injection molding parts mold ensure products degree, requirements mold cavity degree and separation type degree must and products degree versus 适应. generally 讲, precision injection molding parts mold cavity dimensions 公差应 small products 公差 三 separation 之一, need according to products 实际情况 specific 确定. separation type degree (separation type 面平行 degree) main/primary use ensure mold cavity degree. for/regarding small type precision injection molding parts 模, separation type 面平行 degree technology requirements is 0.005mm. injection molding parts mold in structure parts although 不会直接参 and injection molding parts molding, is effect/influence mold cavity degree, 并进而 effect/influence products degree, therefore for it structure parts 提出恰当 combined 理 精 degree. ②确定动, 定模 配 combined degree generally lower, injection molding parts main/primary 依靠导柱导 toward machine ensure its for combined degree. is, due to and toward 孔 间隙配 combined property 质, between or large or small has 一定间隙, 该间隙经常 effect/influence injection molding parts mold in injection molding parts machine upper 安装精 degree, 一导致动模 and 定模两部 separation 发生错移, therefore very difficult use injection molding parts precision products. remove outer, in high temperature injection molding parts conditions lower, 动, sheet/plate hot has 时也会 make between 发生错移, most rear products degree 发生变化. in precision injection molding parts in, 应当尽 amount decrease small 动, between 错移, method ensure and for combined degree, can design 锥面定位 machine or 圆柱导 positive 销定位 machine and 导柱导 toward machine use. ③ injection molding parts mold structure has rigid degree precision injection molding parts must tool has structure rigid degree, 否则, it in injection molding parts pressure or clamping force function lower will 会发生 relatively large elastic property deformation, from 而引起 injection molding parts mold degree 发生变化, therefore effect/influence products degree. for/regarding overall 式凸, 凹模, its structure rigid degree need 由自身 形状 dimensions and injection molding parts mold material ensure, for/regarding 镶拼式凸 凹模, its structure rigid degree also and solid parts use frame has 关. frame material using/adopting alloy structure 钢40Cr, hot hardness requirements HRC30 left right. ④ injection molding parts mold in active 动零部 parts 运动应当准确精 degree injection molding parts in, 往往也会 belt/tape has can active molding block or active type 芯. if this active 动零部 parts 运动不准确, 即每次运动之 rear can 准确 返回 to 原 位置, that 么无论 injection molding parts mold parts processing degree has more high, injection molding parts mold structure degree and products degree therefore 而出现 very large 波动. is solution this issues, need using/adopting comparison 特殊 运动定位 structure. 4.2 避免因 injection molding parts mold design defect make products non-uniform shrinkage design precision injection molding parts 时, if injection molding parts mold structure or temperature degree control system design 不当, easy make products shrinkage rate non-uniform phenomenon, this type of phenomenon for products degree and products degree stability property generate defect effect/influence. is 避免出现 this category of issues, need attention/notes lower 面积点: ①浇注 system amount make material unchanged 衡. ② mold cavity 布排应尽 amount make injection molding parts mold temperature degree maintain hot balanced. ③ temperature system most good can for mold cavity temperature degree mono adjustment. ④凸模 and 凹模两部 separation most good separation cooling water 路. 4.3 避免因 injection molding parts mold issues make products demolding deformation currently precision injection molding parts products dimensions generally 都不太 large, thick comparison thin, has also belt/tape has many thin 肋, therefore very easy in demolding generate deformation, this type of deformation 必然会造 formed products degree decline. is products demolding deformation, attention/notes lower 面三点. ① injection molding parts mold remove tool has rigid degree outer, its structure also need combined products demolding; ② generally 讲, precision injection molding parts products most good use demolding sheet/plate (推 sheet/plate) demolding, this has anti products demolding deformation; ③ precision injection molding parts products demolding degree generally comparison small, large easy demolding. 4.4 for/regarding complex products using/adopting injection molding parts mold structure make products can to relatively high degree, must for mold cavity abrasion 削, for mold cavity can abrasion processing, will products complex degree made. is solution this issues, for/regarding complex precision injection molding parts products, most good will its mold cavity design formed structure. precision molding new technology 5.1 in injection molding parts mold in application injection pressure shrink molding (ICM) technology ICM technology is injection molding parts mold 开启一定距离 conditions lower injection, injection to amount rear, injection molding parts mold 开始闭 combined for type inner melt pressure shrink, injection molding parts mold full combined injection 终止,然 rear holding pressure, cooling to products. injection pressure shrink molding is through pressure shrink is pressure products, make products surface tool has uniform pressure distribution, this pressure products dimensions degree high stability, deformation small. it is in injection molding parts mold 开启 情况 lower will melt type 腔,因而 flow large, injection molding parts pressure very low, and decrease small or remove holding pressure resin separation orientation and products internal stress, from improve/increase products dimensional stability. ICM technology flexible and control can force relatively generally injection has relatively large improve/increase. therefore utilizing this technology can production more high degree made parts, especially is high degree 圆柱状 made parts. 5.2 high speed injection molding parts molding high speed injection molding parts molding methods melt filling speed degree relatively fast 10 ～ 100倍, make melt in mold cavity inner generate high flow, viscosity decline,充模 speed degree fast, plastics surface hard decrease slow,因而 can improve/increase thin products molding thick degree 极限,抑 made degree molding pressure, meanwhile due to inner low pressure flow, products internal stress reduce. for/regarding thin precision products, can utilizing injection molding parts screw front 移引起 melt absorption can amount, in screw 移动停止 rear through melt high speed type achieve. 5.3 无 holding pressure injection molding parts molding holding pressure injection molding parts molding technology is will plastics melt high speed, high pressure 充填入 injection molding parts mold,然 rear 关闭设于 nozzle 针阀,以 mold cavity inner plastics melt 自动弥补 products separation shrinkage, this can large large reduce products warpage deformation. is this type of methods need 事先估计 holding pressure shrinkage 补充部 separation, therefore in injection in need has relatively high type pressure value, need clamping force high. 5.4 its it can control technology precision injection molding parts molding process in for processing conditions 实行持续 property and control non important. 随 计算 machine technology development,计算 machine injection molding parts molding already to application. its in has statistics process control (SPC) technology, P ID technology, 模糊逻辑 control (FCC) methods, in 枢网络 control (NNC) methods and 基于逆 toward processing type in 枢网络 dimensions control and other. 结语随 new technology, new material, new process and new equipment versus 继出现, especially is machine in plastics processing in application, is precision injection technology 创造 良 good conditions, will toward ultra-high speed, ultra- precision, micro type and can direction development and 完善.