模具注塑问题解决

《模具注塑问题解决》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、InjectionMoldingTroubleshootingGuideInjectionMoldingTroubleshootingGuide模具注塑问题解决Problem:BurnMarksAtGate问题：浇口焦斑Generallyburnmarksatthegatearecausedbyanover-shearingofmaterial.Themeltflowwillreachitshighestshearratewhileinthegate.Sincethegatewillalsobethe

2、hottestarea,over-shearingherewillleaveaburnmarkatthegate.一般而言，浇口处的焦斑是由于材料过分剪切造成的。在浇口，熔体受到最大的剪切，因此浇口也成为了最热的地方，过分的剪切将导致在浇口处产生焦斑。GateSize浇口尺寸Usingsmallergatesandhighershearrateskeepsmeltviscositylow,whichimprovesmeltflowofourTPVmaterials.Werecommendusingas

3、smallagateaspossible(toosmallofagatewillover-shearthematerial).Agatesizenosmallerthan0.5mm(0.020")andnolargerthan3.0mm(0.120")isrecommended.RefertotheQuickProcessingReferencesonourwebsiteformoreinformationongatingusingspecificgradesofourTPVs.使用较小的浇口尺寸和较

4、高的剪切率使熔体保持较低的黏度，将会改善TPV材料的流动。我们推荐使用尽可能小的浇口（太小的浇口将会过分剪切材料）。推荐的浇口尺寸应当在0.5mm（0.020”）和3.0(0.120”)mm之间。参考我们网站上的快速过程参考可以获得更多的在使用特殊等级的TPV情况下的浇口方面的信息。RestrictedGate窄型浇口（浇口的限制）Arestrictedgateslowstheflowofmaterialaroundthegatearea,whichincreasestheshearofourTPVm

5、aterials.Restrictionscouldbecausedbyarapidwallthicknesschangeinthepart.Werecommendwallthicknesstransitionsof15percentorless.Burrsorsharpcornersatthegatewillalsoreduceflowatthegate.Polishingthegateareacanreducethisrestriction.窄型浇口减缓了浇口附近的材料的流动，增加了TPV的剪切。

6、零件壁厚的迅速变化能够引起流动的限制，我们推荐的壁厚变化是15%或更少。浇口处的Burr和急转弯也将减缓浇口处的流动，磨光浇口处的面积能够减少这种限制。InjectionSpeedTooHigh注塑速度太快MostofourTPVsprocessusingfastinjectionrates,achievingfilltimesrangingfrom0.5to1.5seconds.However,tryingtoinjecttoorapidlywillincreasetheshearrateofmel

7、tflowinthegate.大多数TPV加工过程使用高速注塑，注满模腔的时间达到0.5秒到1.5秒，然而，尝试更快的注射将增加浇口处熔体的剪切率。BackPressureTooHighSantoprenePage29of29InjectionMoldingTroubleshootingGuide背压太高Arapidwithdrawofthescrewwillover-shearthematerial.Thelastplaceformeltflowtosetupisaroundthegate,whic

8、hincreasesthechanceofaburnmarkinthislocation.螺杆的快速回退会引起材料的过分剪切。设置的熔体的最后位置是在浇口附近，这样会增加这个位置产生焦斑的机会。MoldTemperatureAtGateTooHigh浇口处的模具温度太高Reducingthetemperaturesaroundthegatewillreduceburningatthegate.减少浇口附近的温度将减少浇口处的燃烧。FrontBarrelZ