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ID:39461976
大小:707.32 KB
页数:17页
时间:2019-07-03
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1、InjectionMoldingJudy,Lian03.01.2011注塑成型概论InjectionMoldingConcept.何谓注塑成型所谓注塑成型(InjectionMolding)是指,将已加热融化的材料喷射注入到模具内,经由冷却与固化后,得到成形品的方法。适用于量产与形状复杂产品等成形加工领域。InjectionMolding:Injectthemeltplasticintothemould,Wecangettheproductaftercooling.Useformassproductionandcomplicat
2、edshapeproduct.射出成形工程是以下列六大顺序执行:InjectionMolding6Steps合模ClosetheMould射出ejector保压keeppressure冷却cooling开模openthemould取出产品fetchtheproductInjectdeviceClosemoulddeviceEjectdevicePullshaftmotorhopperScrewstemheatingonewayrestrictorvalvecylinderejectorpinInjectionmouldInjec
3、tionsystermShapepartstructurepartguideFixingpartCoolingandheatsystermgatesprueRunnercoldslugwellscoreinsertcavityinsertmouldingfacepininsertguidepinguidebushFixedmouldplate,A–platemovingmouldplate,B–platesupportplate,backingplate,supportblocks流道的配置Runnerarrangement模腔
4、取多个流道时,流道长度、粗细要相同,使树脂同时充填到各模腔中,并设计成对称形配置,见图7-3所示的流道配置实例。Whenwehavelotofrunner,Thelengthoftherunnershouldbewithsamelength,samesectionsizeandsymmetry,seebelowphoto当通向各模腔的流道长度不相同(不等长流道)、或因配套等原因模腔的体积不相同等情况时,一般还通过改变流道粗细来调节,使之进行同时充填。Whenthecavitysizeisdifferent,wealwaysuse
5、differentrunnerlength,butstillusesamesectionsizerunner.锥角=2°~4°gatesprueRunnerProduct冷料井(coldslugwells)在所有流道之交界处,主流道至少须超过支流道一个直径距离以上。它可以让熔融塑流前端冷的、高黏度的高分子停留于此,,使后方热的、低黏度的高分子易于进入模穴内。所以冷料井能够防止冷料进入模穴而影响最后之产品性质。Ateachrunnercross,Thereshouldbeacoldsungwellsthereandit’sleng
6、thmustmorethatmainrunner’sdiameter.Itwillhelptostopthefrontplasticwhichiscoldfirstlyandwithhighdensity,Soastolethotplasticgointhecavity.Itcanpreventcoldplasticgoinginthecavityandpreventbadaffectionfortheproductqualification.沟槽型:此乃在浇道的侧壁开设几个沟槽,以便塑料冷凝时,能留住冷料。此结构中亦采用浇道顶
7、杆将冷料从冷料井中顶出,此时浇道顶杆直接切过槽里之塑料,使之仍留在槽沟里,在下一次注射周期里,注入之熔融塑料又与槽沟内之冷料融合在一起。Slot:Therearesomegroovesatspruewall.Itwilllocktheplasticwhenplasticgoescold.Thecoldplasticinthegroovewillleavehereafterpushoutothercoldplastic.Thispartofplasticwillcombinewithnextinjectionhotplastic.
8、(b)倒锥型:倒锥面之冷料井是最简单之浇道拉出设计。invertedcone:conicalsurfaceshapeismostcommonuseforpulloutthesprue.(c)Z型:此结构中,浇道顶杆之头部被加工成Z型状,在模具打开时能把冷料钩住.
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