精密注塑技术Aspects for Precise Injection Molding.ppt

精密注塑技术aspectsforpreciseinjectionmolding,2,copyrightbyarburg/nov.2006,内容提要overview,精密注塑的定义definitionpreciseinjectionmolding锁模系统clampingunit锁模力clampingforce选择注射装置的准则criteriatoselecttheinjectionunitselogica控制器selogicacontroller模具设计molddesign模具温度控制moldtemperaturecontrol,3,copyrightbyarburg/nov.2006,精密注塑的定义definitionpreciseinjectionmolding,小的尺寸和公差轻的部件重量为特定产品配备注塑设备灵活的机器配备（一台机器可适用于多种模具)稳定的质量，高的重复性,smallpartdimensionandtolerancelowweightadaptationofmachineperformancetothepartsflexiblemachineconfiguration(manymoldssuitableforonemachine)stablequality,reproducibility,4,copyrightbyarburg/nov.2006,锁模系统clampingunit,合模系统起重要的作用动模板是稳定而经过证实的箱型结构长而精确的导向模板平行度的调节50吨范围内0.05mm极高的刚度,forpreciseinjectionmolding,theclampingtakeoveraveryimportantpart.movableplatenasstableandprovenbox-typeplatenlongandpreciseguidingofthemovableplatenadjustableparallelismupto50to.machines0.05mmhighrigidity,5,copyrightbyarburg/nov.2006,锁模力clampingforce,精密注塑的另一个重要因素是锁模力。原因是：模腔更好的排气（90%的空气从分型面排出）减少机器和模具的磨损节省能源oneotherimportantaspectforpreciseinjectionmoldingistheclampingforce.reasonsforthatare:muchbetterventingofthecavitiesduringinjection.(ca.90%oftheairinsidethecavityescapeoverthepartingline)topreventmachineandmoldfromunnecessarywear.savingenergy,6,copyrightbyarburg/nov.2006,锁模力clampingforce,怎样计算锁模力锁模力=单位锁模力x(产品投影面积+流道投影面积）如果有滑块，需要将滑块投影面积的30%加入产品投影面积howtocalculatetheclampingforce?ifthemoldcontainssliders!youhavetoadd30%oftheprojectedsliderareatotheprojectedareaofmoldedpart.,7,copyrightbyarburg/nov.2006,锁模力clampingforce,单位锁模力的确定可使用以下图表todefinethenecessaryspecificclampingforce,useoneofthepicturesbelow.,forstandardpartsforthinwalledpartswithlongflowpaths,8,copyrightbyarburg/nov.2006,锁模力clampingforce,举例example:接插件connectorpa6长度length:6cm宽度width:1.5cm浇道投影面积proj.areasprue:8cm2单位锁模力spec.clampingforce:6kn/cm2模穴数8cavities,9,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,10,copyrightbyarburg/nov.2006,每一机器尺寸eachmachinesize,三个注射单元3injectionunits,三个料筒规格3cylindersizes,选择注射单元规格的准则criteriatoselecttheinjectionunit,模块化modularity,11,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,注射单元的欧洲橡塑机械协会(euromap)规格表示注射单元的最大注射功。计算方法最大注射压力x最大行程容量/1000举例按注塑机320c600-250规格表最大注射压力(35mm螺杆）：1820bar最大行程容量144ccm1820barx144ccm/1000250,thesizeoftheinjectionunitisaccordingtoeuromapandindicatestheworkingperformanceoftheinjectionunit.theworkingperformanceiscalculatemax.spec.injectionpressurexmax.strokevolume/1000example:accordingtothetechnicaldataof320c600-250max.injectionpressure(screwdiameter35mm)=1820barmax.strokevolume=144cm31820barx144cm3/1000250,12,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,注射功workingperformance,!相同螺杆直径，但不同注射压力!samescrewdiameterbutdifferentmax.injectionpressure,13,copyrightbyarburg/nov.2006,选择注射量的准则selectioncriteriashotvolume,选择注射单元规格的准则criteriatoselecttheinjectionunit,14,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,example:connector(pa6),8cavities,26.5gshotweightresultsaccordingthelistbelow:,(1)theinjectionvolumemustbeonaverage25%greaterthanthevolumeoftheinjectedpart(incl.sprue)duetoshrinkageduringsolidifyingandduetothecompressionofthemeltduringinjection.,15,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,example:connector(pa6),8cavities,26.5gshotweight2ndexample,calculationwithshotweightresultsaccordingthelistbelow:,16,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,滞留时间准则滞留时间=塑胶进入料筒到离开喷嘴的时间pe,pp,ps:最少30秒(大于40秒为好)pa,pom,pbt:最少60秒(75秒为好),selectioncriteriadwelltimedwelltime=fromtheentreeofmaterialintothecylinderuntiltheexitoutofthenozzles,e.g.pe,pp,ps:min.30s(better40s)e.g.pa,pom,pbt:min.60s(better75s),17,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,example:connector(pa6),8cavities,26.5gshotweight(29.31cm3)resultaccordingtothelistbelow,dwelltimeforpa6min.60sec.,remarks:anextendedscrewandcylindercanincreasethedwelltime!,18,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunit,selectioncriteriamaterialthroughputexample:connector(pa6),8cavities,26.5gshotweight,19,copyrightbyarburg/nov.2006,错误的选择会造成mistakesinselectioncausese.g.to-不完全熔化的粒料-unmeltedgranulate-混色不均-colorsteaks-烧焦-burntstreaks,选择注射单元规格的准则criteriatoselecttheinjectionunit,20,copyrightbyarburg/nov.2006,其他准则包括所用材料的加工温度有些工程材料（如peek,pei,lcp等）需要接近450摄氏度的加工温度料筒加热圈应使用陶瓷绝缘加热圈furthercriteriafortheinjectionunitisthetemperaturerangeofmaterialtobeused.somehightechnologyplastics(e.g.peek,pei,lcp,etc)requiresatemperaturereleaseofthemachineupto450(500)deg.c.thereforetheplasticizingcylinderhastobeequippedwithceramicisolatedheaterbands.,选择注射单元规格的准则criteriatoselecttheinjectionunits,21,copyrightbyarburg/nov.2006,选择注射单元规格的准则criteriatoselecttheinjectionunits,-注射控制的方式-conceptionsofinjectionregulation-标准方式：注射闭环控制basicconfigurationinjectionregulation扩展方式（可选件）：螺杆精确定位extensionstage(option)positionregulationscrew(prs),22,copyrightbyarburg/nov.2006,注射闭环控制的原理functionprincipleoftheinjectionregulation,选择注射单元规格的准则criteriatoselecttheinjectionunits,螺杆精确定位positionregulatedscrew,23,copyrightbyarburg/nov.2006,螺杆精确定位的原理functionprincipleofthepositionregulatedscrew,选择注射单元规格的准则criteriatoselecttheinjectionunits,injectioncontrol注射控制,positionregulatedscrew螺杆精确定位,24,copyrightbyarburg/nov.2006,螺杆精确定位效果举例微型齿轮examplefortheefficiencyofthepositionregulatedscrewwithamicrogearwheel,选择注射单元规格的准则criteriatoselecttheinjectionunits,25,copyrightbyarburg/nov.2006,效果举例（改变进料量）examplefortheefficiency(variationdosagevolume):,选择注射单元规格的准则criteriatoselecttheinjectionunits,26,copyrightbyarburg/nov.2006,注射闭环控制与螺杆精确定位比较injectionregulationincomparisonwithpositionregulation,injectionspeedcurve,pressurecurve,injectionspeed,screwposition,27,copyrightbyarburg/nov.2006,selogica控制器,清楚显示动作顺序transparentdisplayofthesequence,28,copyrightbyarburg/nov.2006,使用曲线图像优化工艺过程，发现错误processoptimizationthroughgraphicdisplayandidentificationoferrors设定压力过低机器不能调节注射速度nominalinjectionpressuresettingtoolowmachinenoabletoregulateinjectionspeed设定压力过高如果产品没有顶出或浇口冷却，有损坏模具的危险nominalinjectionpressuresettingtoohighriskofdamagemoldifonepartstickinginsidethemold,orincaseofcoldslugs,selogica控制器,29,copyrightbyarburg/nov.2006,使用曲线图像优化工艺过程，发现错误processoptimizationthroughgraphicdisplayandidentificationoferrors,此例中转压切换点1太早。此时模腔只有6070%满而不是95%满。以后是由保压充模工艺不稳定，产品质量不稳定inthisexample,thesetpoint(1)ofswitchoverintoholdingpressureistooearly.withinjectionthepartisonly60-70%full,insteadof95%.therestwillbefilledbyholdingpressure.unstableprocessandunstablepartquality,selogica控制器,30,copyrightbyarburg/nov.2006,使用曲线图像优化工艺过程，发现错误processoptimizationthroughgraphicdisplayandidentificationoferrors,selogica控制器,正确的设定goodsettings,31,copyrightbyarburg/nov.2006,selogica控制器,模具内压精密注塑的另一方面是模具内压。保压时模具内压的变化对产品质量，如尺寸，重量，内应力，有直接影响。,moldcavitypressureasafurtheraspectforprecisionmoldingisthemoldcavitypressure.theprogressofthepressureduringholdinghasadirectinfluenceofthepartqualitye.g.dimensions,partweightandstresses.,32,copyrightbyarburg/nov.2006,模腔压力moldcavitypressure两种压力曲线类型twodifferentpressurecurves,selogica控制器,无规型塑料amorphousplasticse.g.ps,abs,pc,pmma,pei,psu,半结晶型塑料partiallycrystallineplasticse.g.pp,pom,pa,peek,pbt,pet,cavitypressure,cavitypressure,time,time,33,copyrightbyarburg/nov.2006,内压测量原理压电式系统，kistler,priamus,应变片式系统，dynisco,cavitypressuremeasuringprinciplespiezo-electricsystemkistler,priamus,dms(straingaugesystem)dynisco直接测量directmeasurement间接测量indirectmeasurement,selogica控制器,1moldcavity2transmissionelement3forcetransducer(measuringtongue),1moldcavity2pressuretransducer,34,copyrightbyarburg/nov.2006,内压测量cavitypressuremeasuring直接测量感应器安装位置sensorlocationsfordirectmeasuring,selogica控制器,35,copyrightbyarburg/nov.2006,机器控制器可显示模具内压力cavitypressureinmachinedisplay,selogica控制器,36,copyrightbyarburg/nov.2006,切换到保压的不同方法switchoverpossibilitiesintoholdingpressure按照模腔内压viacavitypressure使用温度感应器（安装在模腔内最后填充点）viatemperaturesensor(placedatflowpathendinthemold),selogica控制器,37,copyrightbyarburg/nov.2006,图像显示过程参数graphicaldisplayoftheprocessparameters根据实际测量值监视产品质量qualitymonitoringbasedonactualparametervalues,selogica控制器,38,copyrightbyarburg/nov.2006,工艺参数和图像的监视monitoringofprocessparametersandgraphicaldisplay,selogica控制器,39,copyrightbyarburg/nov.2006,曲线监视curvemonitoring,selogica控制器,40,copyrightbyarburg/nov.2006,产品质量记录qualitydocumentation,selogica控制器,41,copyrightbyarburg/nov.2006,用图像记录工艺参数测量值graphicdisplayofprocessactualvalues,selogica控制器,42,copyrightbyarburg/nov.2006,模具设计方面aspectofmoulddesign,流道设计(特别是小产品)用冷流道流道长度取决于模具刚性和复杂程度必须选择足够的横截面积用热流道加热的流道增加材料滞留时间热流道需要足够的空间延长的喷嘴需要注意事项与热流道相同需要附加的加热圈,spruedesign(especiallysmallparts)viacold-runnersystemspruelengthistheresultfrommoldstabilityandmoldcomplexitythespruesectionmustbeselectedbigenoughviahot-runnersystemsheatedspruechannelincreasesthedwelltimeproblemswithspaceviaextendednozzletipsameproblemlikewithhot-runnersystemsadditionalheaterbandnecessary!,43,copyrightbyarburg/nov.2006,模具设计方面aspectofmoulddesign,排气venting,44,copyrightbyarburg/nov.2006,模具设计方面aspectofmoulddesign,研磨方向互相交叉排气容易,90%空气从分型面排出easyventing.approx.90%ofairescapesoverpartingline空气可从整个模腔接触面排出theaircanescapeoverthecompletecavityarea成本低lowcosts,1分型面光洁度0.0070.009mm1partinglineroughness0.0070.009mm2模芯光洁度0.0030.004mm2cavityinsertroughness0.0030.004mm,45,copyrightbyarburg/nov.2006,排气槽ventingchannel在流道终点或熔体相交处attheendoftheflowpathorwherethemeltfrontsmeetstogether可随时开出afterwardscreationpossible会积累脏物，需定时清理problemsofdirtdepositionthusoftencleaning,模具设计方面aspectofmoulddesign,1ventingchannel(0.010.02mm),46,copyrightbyarburg/nov.2006,溢流槽排气overspillventing在流道终点或熔体相交处attheendoftheflowpathorwherethemeltfrontsmeettogether排气效果好goodventing防止熔合线preventionfromweldlinesinthatarea需切掉余料afterwardsremovalofoverspillchannel,模具设计方面aspectofmoulddesign,1meetpointwithenclosedair2injectionpoint3overspillchannel(ventingthroughmeltfrontmeetpointshiftingintooverspillchannel,47,copyrightbyarburg/nov.2006,模具设计方面aspectofmoulddesign,对中系统centeringsystem,对中系统centeringsystem,48,copyrightbyarburg/nov.2006,模具设计方面aspectofmoulddesign,对中系统center