Shanghai Daoqin Plastics Co., Ltd.

injection molding products generate defect causes and its methods; in injection molding processing process in can can due to raw materials 处理不 good, products or; for plastics products evaluation main/primary has 三 方面, is appearance quality production 实践证明, products defect main/primary in mold design, manufacturing; injection molding products warpage deformation analysis; warpage deformation is injection molding products 形状偏离 mold type 腔 形状 一, mold structure for injection molding products warpage deformation effect/influence; in mold design 方面, effect/influence parts deformation factors main/primary has system; （1）浇注
injection molding products generate defect causes and its methods

in injection molding processing process in can can due to raw materials 处理不 good, products or mold design combined 理, technology 人员没 has combined process as conditions, or machine 械方面 causes, make products generate 注不满, 凹陷, flash, bubbles, cracks, warpage deformation, dimensions and other defect.

for plastics products evaluation main/primary has 三 方面, is appearance quality, 包括完整 property, color, gloss and other; is dimensions and versus for 位置间 准确 property; is and applications versus mechanical properties, chemical property can, electrical property can and other. this quality requirements also according to products use combined different, requirements degree different.

production 实践证明, products defect main/primary in mold design, manufacturing degree and abrasion loss degree, process adjustment and as 不当, equipment machine fault/failure, material selection and 处理不当 and other more 方面引起, therefore in production in 应客观 analysis defect true positive causes. production process in process adjustment is improve/increase products quality and output/production volume necessary 途径. in adjustment process most good one-time 改变一 conditions, more 观察几回, if pressure, temperature degree, time 统统一起调 话, very easy formed mixed and understanding, issues 也不知道 is 何道理. adjustment process measures, is more 方面. 例如: solution products 注不满 issues has more can can solution 途径, need selection solution issues 症结 一, main/primary solution/scheme, to issues true positive causes, can has solution issues. in addition, also attention/notes solutions in 辨证关系. ratio 如: products 出现 凹陷, has need improve/increase material temperature, has need reduce material temperature; has need increase material amount, has need decrease/reduce material amount. need 承认逆 toward measures solution issues can property.

injection molding products warpage deformation analysis

warpage deformation is injection molding products 形状偏离 mold type 腔 形状, it is plastics products Common defect 之一. plastics industrial development, for plastics products appearance and use property can requirements 越 越 high, warpage deformation degree as is product quality important indicators 之一也越 越 more to mold design 者 关注 and heavy 视. mold design 者希望 in design stage/phase forecast plastics parts can can generate warpage causes, add optimization design, from improve/increase injection molding production efficiency and quality, shrink short mold design cycle, reduce cost.

一, mold structure for injection molding products warpage deformation effect/influence

in mold design 方面, effect/influence parts deformation factors main/primary has system, cooling system and ejection system and other.

（1）浇注 system design

injection molding mold gate 位置, and gate amount will effect/influence plastics in mold type inner filling 状态, from 而导致塑 parts generate deformation. flow 距离越 long, 由冻结层 and in flow between flow and shrink internal stress large; 反之, flow 距离越 short, from gate to made parts flow flow time short, 充模时冻结层 thick degree decrease thin, internal stress reduce, warpage deformation therefore large is decrease/reduce. large type sheet/plate parts, if use in gate or 一 侧 gate, 因直径 direction upper shrinkage rate large 于圆周 direction upper shrinkage rate, molding rear parts generate deformation; use more gate or film type gate, can has anti warpage deformation.

当 using/adopting 点浇进行 molding 时, due to plastics shrinkage toward property, gate 位置, amount for parts deformation degree has very large effect/influence;实验 table/sheet 明, gate tool very important, non gate 数目越 more good.

another, more gate use also can make plastics flow ratio （L／t） shrink short, from make mold cavity inner material material density more uniform, shrinkage more uniform. meanwhile, 整 塑 parts can in relatively small injection molding pressure lower 充满. relatively small injection pressure can decrease/reduce plastics separation orientation toward, reduce its internal stress, can decrease/reduce parts deformation.

（2） cooling system design

in injection process in, parts cooling speed degree non-uniform will formed parts shrinkage non-uniform, this type of shrinkage 差别导致 bending force generate make parts warpage.

if in injection molding sheet/plate parts use mold type 腔, type temperature degree versus large, due to cold mold cavity melt very fast cooling lower, 而贴近 hot mold cavity material 层则会继续 shrinkage, shrinkage non-uniform will make parts warpage. therefore, injection molding cooling attention/notes type 腔, type temperature degree balanced, temperature can large.

remove 考虑塑 parts inner outer surface temperature degree balanced outer, also 应考虑塑 parts temperature degree 一致, mold cooling need amount maintain type 腔, type 芯各处 temperature degree uniform 一致, make parts cooling speed degree 均衡, from make shrinkage more uniform, has anti deformation generate. therefore, mold upper cooling water 孔 布置至关 important. in tube/pipe type surface 距离确定 rear, can can make cooling water between small, can ensure type temperature degree uniform 一致. meanwhile, due to cooling temperature degree cooling water long degree increase upper rise, make mold type 腔, type water generate temperature 差. in large type mold in 应设置数 strip/profile cooling 回路, strip/profile Imported 位于另一

strip/profile export 附近. for/regarding long strip/profile parts, using/adopting cooling 回路, decrease/reduce cooling long degree, decrease/reduce mold temperature 差, from ensure parts uniform cooling.

（3） ejection system design

ejection system design 也直接 effect/influence parts deformation. if ejection system 布置不 balanced, will formed ejection force balanced make parts deformation. therefore, in design ejection system force and demolding retardant force versus balanced. another, ejection 杆 截面积不 can small, anti parts mono 位面积受 force large （ especially in demolding temperature degree high 时）而 make parts generate deformation. 顶杆 布置应尽 amount demolding retardant force large 部位. in effect/influence parts quality （包括 use requirements, dimensions degree and appearance and other ） front lower, can can more 设顶杆以 decrease/reduce parts deformation.

use soft plastics production large type deep thin 壁 塑 parts 时, due to demolding retardant force relatively large, material also relatively soft, if full using/adopting mono machine ejection methods, will make parts generate deformation, 甚至顶穿 or generate 折叠而造 formed parts waste, use more parts combined or gas （ liquid ） pressure and machine ejection versus combined methods 效果会 more good.

二, stage/phase for products warpage deformation effect/influence

塑化 stage/phase 即玻璃态 material 粒转化 is viscous 流态, provide 充模 需 melt. in this process in, polymer temperature degree in toward, toward (versus for screw 而言) temperature make plastics generate force; another, injection machine injection pressure, speed degree and other parameters large effect/influence 充填时 separation orientation degree, 进而引起 warpage deformation.

三, and cooling stage/phase for products warpage deformation effect/influence

熔 melt plastics in injection pressure function lower, mold type in type inner cooling, solid process is injection molding key/critical step/link. in this process in, temperature degree, pressure, speed degree versus combined function, for parts quality and production efficiency has large effect/influence. relatively high pressure and speed generate high speed rate, from 而引起平行于 flow direction and 垂直于 flow direction separation orientation 差异, meanwhile generate “冻结效应”. “冻结效应” will generate 冻结应 force, formed parts internal stress. temperature degree for warpage deformation effect/influence in below/following several 方面.

(1) parts upper, lower surface temperature 差会引起 hot force and hot deformation;

(2) parts different between temperature degree will different 区域间 non-uniform shrinkage;

(3) different temperature degree 状态会 effect/influence plastics parts shrinkage rate;

四, demolding stage/phase for products warpage deformation effect/influence

塑 parts in type cooling room temperature process in more is 玻璃态 polymer. demolding force balanced, launch machine 构运动不平稳 or demolding ejection 面积不当 very easy make products deformation. meanwhile, in and cooling stage/phase in parts inner force due to outer 界 约束, will deformation 形式释放出, from 而导致 warpage deformation.

五, injection molding products shrinkage for warpage deformation effect/influence

injection molding products warpage deformation causes in parts non-uniform shrinkage. if in mold design stage/phase 不考虑 filling process in shrinkage effect/influence, products 几何形状会 and design requirements versus very large, heavy deformation make products waste. remove filling stage/phase 会引起 deformation outer, mold upper lower temperature degree will 引起塑 parts upper lower surface shrinkage 差异, from generate warpage deformation.

for warpage analysis 而言, shrinkage 本身并不 important, important is shrinkage upper 差异. in injection molding process in, melt plastics in injection stage/phase due to polymer separation flow direction make plastics in flow direction upper shrinkage rate ratio direction shrinkage rate large, make injection molding parts generate warpage deformation. generally uniform shrinkage plastics parts upper 变化, has non-uniform shrinkage 才会引起 warpage deformation. crystallization type plastics in flow direction and direction upper shrinkage rate relatively non crystallization type plastics large, but also its shrinkage rate relatively non crystallization type plastics large, crystallization type plastics large shrinkage rate and its shrinkage toward property add rear crystallization type plastics parts warpage deformation toward relatively non crystallization type plastics large more.

六, separation orientation 不均衡

thermoplastic property plastics warpage deformation very large degree upper 取决于塑 parts toward and toward shrinkage value, this value is separation orientation generate.

usually, parts in molding process in, material flow direction upper separation orientation large 于垂直 flow direction upper separation orientation, this is due to 充模时 large separation polymer separation flow direction 排列造 formed, 充模结束 rear, by orientation separation 子形态总 is force 图恢复原 has 卷曲状态, 导致塑 parts in direction upper long degree shrink short. therefore, parts material flow direction upper shrinkage large 于垂直 flow direction upper shrinkage. due to in 两 垂直 direction upper shrinkage 不均衡, parts generate warpage deformation.

is amount decrease/reduce due to separation orientation generate warpage deformation, 应创造 conditions decrease/reduce flow orientation and and orientation force 松驰, its in most is has methods is reduce material temperature degree and mold temperature degree. in using/adopting this methods 时, most good and parts hot 处理结 combined 起, 否则, decrease small separation orientation 差异 效果往往 is property. is material temperature and mold temperature relatively low 时, material cooling very fast, parts inner 会残留 a large amount of internal stress, make parts in in the future use process in or ring temperature degree rise high still 旧出现 warpage deformation.

if parts demolding rear 立即进行 hot 处理, will its relatively high temperature degree lower maintain time again cold room temperature, can a large amount of remove parts inner orientation force, hot methods is; demolding rear will parts 立即置于37.5~43 degree temperature water in its slow cooling.

七, 结论

effect/influence injection molding products warpage deformation factors has very more, mold structure, plastics material hot physical properties and injection molding process conditions and parameters for products warpage deformation has different degree effect/influence. therefore, for injection molding products warpage deformation mechanism research must comprehensive 考虑整 molding process and material property can and other more factors.

flash （披锋）

溢 material also flash, 溢边, and other, large more in mold separation type upper, 如: mold separation type 面, slip block slip 配部位, parts 缝隙, 顶杆 孔隙 and other 处. material and solution will 会进一步 expand large 化, from pressure mold formed local 陷塌, formed property loss 害. parts and 顶杆孔隙 溢 material also make products in upper, effect/influence demolding.

一, equipment 方面

（1） machine true positive clamping force 不足. selection injection molding machine 时, machine clamping force must high injection molding products toward 投影面积 in injection formed force, will formed 胀模, flash.

（2） clamping plant/unit adjustment 不佳, machine has 伸直, generate or left right or upper lower clamping 不均衡, mold degree can to phenomenon formed mold mono 侧一边 by combined 紧而另一边不密贴 情况, injection will flash.

（3） mold 本身平行 degree 不佳, or 装 不平行, or sheet/plate 不平行, or 拉杆受 force distribution 不均, deformation 不均, this will formed clamping 不紧密而 generate flash.

（4）止回 ring abrasion loss heavy; elastic nozzle elastic 簧失效; material or screw abrasion loss large; material cooling system 失效造 formed “架桥” phenomenon; 导致计 amount and amount unstable and other can can formed flash 反复出现, must and repair or more parts.

二, mold 方面

（1） mold separation type degree 差. active sheet/plate （如 in sheet/plate ） deformation warpage; separation type upper viscous has material or frame has 凸出 橇印毛刺; mold 因早先 flash pressure make type 腔周边 fatigue 塌陷.

（2） mold design combined 理. mold type 腔 开设位置 偏, injection mold mono 边发生张 force, flash; plastics flow property good, polyethylene (PE), polypropylene (PP), nylon and other, in melt lower degree very low, easy active or solid 定 缝隙, requirements mold manufacturing degree relatively high; in effect/influence products property front lower amount in quality for in upper, in products thick 实 部位入 material, can anti 止一边缺 material belt/tape flash 情况; products in or its has molding 孔时, upper in upper 开设侧 gate, in relatively large injection pressure lower, if clamping force 不足模 this separation function force 不够发生 light micro warpage formed flash, mold belt/tape has active parts 时, its 侧面 投影面积也受 molding pressure function, if force 不够也会造 formed flash; sliding type combined degree defect or solid type and type 腔安装位置偏移而 generate flash; type gas defect, in separation type upper has gas or gas shallow or deep large or material retardant will formed flash; for more type mold attention/notes separation runner combined gate combined design, will formed 充模受 force 不均而 generate flash.

三, process 方面

（1） injection pressure high or injection speed degree fast. due to high pressure high speed, for mold force increase large 导致溢 material. need according to products thick thin adjustment injection speed degree and injection time, thin products need use high speed speed 充模, rear again 进注; thick products need use low speed 充模, let table/sheet in to pressure front large solid lower.

（2） add material amount large formed flash. value attention/notes is need is anti 止凹陷而注入 more material, this 样凹陷未必 can “填平”, flash 却会出现. this type of application long injection time or holding pressure time solution.

（3） machine 筒, nozzle temperature degree high or mold temperature degree high make plastics degree decline, flow property increase large, in 流畅进模 情况 lower formed flash.

四, raw materials 方面

（1） plastics degree high or low can can flash. degree low plastics nylon, polyethylene (PE), polypropylene (PP) and other, improve/increase clamping force; water property strong/high plastics or for water plastics in high temperature lower large degree reduce flow degree, increase flash can can property, for this plastics must drying; recycled material more plastics degree decline, necessary need 补充滞留 formed separation. plastics degree high, flow retardant force increase large, generate large back pressure make mold cavity pressure improve/increase, formed clamping force 不足而 generate flash.

（2） plastics raw materials degree large small 不均时会 make add material amount 变化不定, made parts or 不满, or flash.

缺 material

this is 一 经常遇 to issues, comparison easy solution. use process 手段确实 solution 不 时, can from mold design manufacturing upper 考虑进行改进, generally is can solution.

一, equipment 方面:

（1） injection molding machine 塑化容 amount small. products quality ultra- injection molding machine most large injection quality 时, 显然 供 material amount is 入不敷出. products quality injection molding machine injection quality 时, has 一 塑化不够充 separation issues, material in machine inner hot time 不足, 结果不 can and toward mold provide 适当 熔 material. this type of has more amount large injection molding machine can solution issues. has plastics nylon （ especially is nylon 66 ）熔 melt scope/range narrow, ratio hot relatively large, use 塑化容 amount large injection molding machine can ensure material supply.

（2） temperature degree 计显示 temperature degree true 实, high low, formed material temperature low. this is due to temperature plant/unit hot electrical and its or temperature milli 伏计失灵, or is due to 远离测 temperature electrical hot aging or 烧毁, add temperature 失效而 also 未曾发现 or has and 时修复 more 换.

（3） nozzle inner 孔直径太 large or small. small, due to 流通直径 small, material ratio increase large, easy cold, 堵塞进 material or consumption injection pressure; large, 则流通截面积 large, plastics mono 位面积 pressure low, formed force small 状况. meanwhile non type plastics 如ABS因没 has obtain large hot can make degree decline formed 充模困 difficult. nozzle and runner 入口配 combined defect, 常常发生模 outer material, inner 充不满 phenomenon. nozzle flow retardant force very large or has material, plastics 炭化沉积 material and other 堵塞; nozzle or runner 入口球面 loss 伤, deformation, effect/influence and for 方 良 good combined; injection base/seat machine fault/failure or 偏差, make nozzle and runner generate 倾侧位移 or toward pressure 紧面脱离; nozzle ratio runner 入口球径 large, 因边缘出现间隙, in material lower increase large nozzle toward force 都会造 formed products 注不满.

（4） plastics block add material 通道. due to plastics in material drying device inner local 熔化结 block, or machine material temperature degree high, or plastics and other grade selection 不当, or plastics inner lubricant more make plastics in 进入进 material pressure shrink or screw 起螺端 deep inner 早 熔化, material and material versus 黏结形 formed “ 桥”, 堵塞通道 or screw, screw as sliding, can front 移, formed material in or random 则波动. this type of has in 凿通通道, troubleshooting material block rear can to solution.

（5） nozzle cold material 入模. injection molding machine usually 都因顾 and pressure loss 失而 装直通式 nozzle. is if machine front and nozzle temperature degree high, or in high pressure lower machine front material more, generate “流涎”, make plastics in 未开始 injection mold 敞开 情况 lower, outer 抢先进入主 runner runner in sheet/plate cooling function lower hard, 而妨碍熔 material 顺畅 进入 type 腔. this 时, reduce machine front and nozzle temperature degree and decrease/reduce machine 筒 储 material amount, decrease low back pressure pressure and increase 松退避免 machine front material density large generate 流涎.

（6） injection molding cycle short. due to cycle short, material temperature and upper 也会造 formed material, in electrical pressure large especially obvious. need according to electrical electrical pressure for cycle as versus adjustment. adjustment generally 不考虑 injection and holding pressure time, main/primary adjustment from holding pressure to screw that time, effect/influence molding conditions, also can long or shrink short material in machine inner preheating time.

（7）止回 ring abrasion loss heavy; or screw abrasion loss large; material cooling system 失效造 formed “架桥” phenomenon; 导致计 amount and amount unstable and other can can formed material 出现, must and repair or more parts.

二, mold 方面

（1） mold system has defect. runner small, thin or long, increase retardant force. runner increase 直径, runner, separation runner formed relatively good. runner or gate large, force 不足; runner, gate has 杂质, material or material 堵塞; runner, gate coarse has 伤痕, or has 锐角, surface coarse degree defect, effect/influence material 流不畅; runner has cold material or cold material small, direction for; for/regarding more type mold need fine runner and gate large small separation 配 均衡, 否则会出现 has runner or gate coarse short type can 够注满而 its it type can 注满 情况. 应适当 add coarse runner 直径, make to runner 末端 熔 material pressure drop decrease/reduce, also need add large runner relatively type gate, make type 腔 注入 pressure and material speed degree basic 一致.

（2） mold design combined 理. mold separation complex, more, gate selection 不当, runner narrow, gate amount or 形式不

当; products local very thin, increase products or local thick degree, or in filling 不足处 附近设置辅助 runner or gate; mold cavity inner gas measures force formed made parts phenomenon is 屡见不鲜, this type of defect large more in products 转弯处, deep 凹陷处, by thick separation thin separation and use gate molding thin housing/shell and other 处. remove this type of defect design 包括开设 has 效 排 gas 孔道, selection combined gate make gas easy 预先排出, necessary 时特意 will type 腔 困 gas certain local made formed parts, make gas from parts 缝隙溢出; for/regarding more type mold easy gate separation balanced 情况, necessary decrease/reduce injection type 腔 数 amount, ensure its it type made parts combined 格.

三, process 方面

（1）进 material adjustment 不当, material or more material. add material amount or add material control system as positive 常, injection molding machine, mold or as conditions 限导致 injection cycle 反常, back pressure small or machine inner material density small can can formed material, for/regarding pellets large, more material and crystallization property ratio 容变化 large plastics polyethylene (PE), polypropylene (PP), nylon and other and degree relatively large plastics 如ABS应调 relatively high material amount, material temperature high 时应调 large material amount.

当 machine 筒端部存 material more 时, injection screw need consumption outer more injection pressure pressure 紧, machine inner ultra- 额囤 material, this large large reduce mold cavity plastics has pressure make products difficult 以充满.

（2） injection pressure low, injection time short, screw 退回太早. melt plastics in low as temperature degree lower degree relatively high, flow property 差, relatively large pressure and speed degree injection. ratio in made ABS color made parts 时, color agent high temperature resistance property made machine add hot temperature degree, this need ratio usually high injection pressure and long injection time 弥补.

（3） injection speed degree slow. injection speed degree for/regarding 一 形状 complex, thick thin large, process/workflow long products, and degree relatively large plastics tool has separation 突出 意义. using/adopting high pressure can products 时, can using/adopting high speed injection can 克服注不满 毛病.

（4） material temperature low. front temperature degree low, type 腔 熔 material due to mold cooling function make degree upper rise to difficult flow 步, for 远端 充模; machine rear temperature degree low, degree large plastics flow difficult, retardant screw front 移, 结果造 formed pressure table/sheet pressure 足够而实际 upper material in low pressure low speed lower type 腔; nozzle temperature degree low can can is solid add material nozzle long time and cold mold dispersion hot amount, or nozzle add hot hot or defect formed material temperature low, can can mold material 通道; if mold belt/tape cold material 井, use nozzle, using/adopting rear add material 程序, nozzle relatively can maintain temperature degree.

四, raw materials 方面

plastics flow property 差. production in use recycled material, recycled material 往往会反映出黏 degree increase large toward. 实验指出: due to oxidation understanding formed separation 子断链 mono 位体积 density increase, this increase in machine and type inner flow viscous property, recycled material long relatively more gas material generate, make injection pressure loss increase large, formed 充模困 difficult. is improvement plastics flow property, 应考虑 add outer lubricant hard acid or its salt type, most good use silicon 油（黏 degree 300~600cm2/s）. lubricant add improve/increase plastics flow property, also improve/increase stability property, decrease/reduce gas material gas retardant.

熔接痕（结 combined 线）

fault/failure analysis and troubleshooting methods

一, equipment 方面: defect, melt temperature degree 不均, can long cycle, make more full, necessary more 换塑化容 amount large machine.

二, mold 方面

（1） mold system structure parameters for material 熔接状况 has very large effect/influence, is defect main/primary generate material separation combined. therefore, amount using/adopting separation less gate 形式并 combined selection gate 位置, amount 避免充模 speed rate 不一致 and material in 断. in can can conditions lower, selection 一点式 gate, is this type of gate generate more material 流, material from direction combined, easy 避免熔接痕.

if mold system in, gate more or small, more gate 定位不 positive or gate to material 熔接处 间距太 large, system runner Imported and separation runner runner 截面太 small, material retardant force large 都会引起熔接 defect, make parts surface generate relatively 明现 熔接痕. for 此, can can decrease/reduce gate 数, combined 理设置 gate 位置, add large gate 截面, 设置辅助 runner, expand large runner and separation runner 直径.

mold cooling system design combined 理, material solid fast, parts temperature degree low, is anti low temperature material mold cavity generate 熔接痕, in improve/increase mold temperature degree meanwhile in mold inner cold material 穴.