塑胶模基础知识.pptx

#,C O N S U L T I N G&E N G I N E E R I N G,Muokkaa tekstin perustyylej napsauttamalla,toinen taso,kolmas taso,neljs taso,viides taso,4.3.2011,Injection Molding,Judy,，,Lian,03.01.2011,注塑成型概论,Injection Molding Concept,.,何谓注塑成型,所谓注塑成型（,Injection Molding,）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。,Injection Molding:Inject the melt plastic into the mould,We can get the product after cooling.,Use for mass production and complicated shape product.,射出成形工程是以下列六大顺序执行：,Injection Molding,6 Steps,合模,Close the Mould,射出,ejector,保压,keep pressure,冷却,cooling,开,模,open the mould,取出产品,fetch the product,Inject device,Close mould device,Eject device,Pull shaft,motor,hopper,Screw stem,heating,one way restrictor valve,cylinder,ejector pin,Injection mould,Injection,systerm,Shape part,structure part,guide,Fixing part,Cooling and heat systerm,gate,sprue,R,unner,cold,slug,wells,core,insert,cavity insert,moulding face pin,insert,guide pin,guide bush,Fixed mould plate,A plate,moving mould plate,B plate,support plate,backing plate,support blocks,流道的配,置,R,unner arrangement,模腔取多个流道时，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,。,When we have lot of runner,The length of the runner should be with,same length,same section size and symmetry,see below photo,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,。,When the cavity size is different,we always use different runner length,but still use same section size runner.,锥角,=2 4,gate,sprue,R,unner,Product,冷料井,(cold slug wells),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。,At each runner cross,There should be a cold sung wells there and its length must more that main runners diameter.,It will help to stop the front plastic which is cold firstly and with high,density,So as to let hot plastic go in the cavity.,It,can prevent cold plastic going in the cavity and prevent bad affection for the product qualification.,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:T,here are some grooves at sprue wall.It will lock the plastic when plastic goes cold.The cold plastic in the groove will leave here after push out other cold plastic.This part of plastic will combine with next injection hot plastic.,(b),倒锥型：倒锥面之冷料井是最简单之浇道拉出设计。,inverted cone:conical surface shape is most common use for pull out the sprue.,(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,.,Z shape:,The ejector pin will be machine to a Z shape.It will hook the cold plastic when open the mould.,nylon latch lock normal structure,1,、热固性塑料,(Thermosetplastics),：指的是加热后，会使分子构造结合成网状型态。,一但结合成网状聚合体，即使再加热也不会软化，显示出所谓的,非可逆变化,，,是分子构造发生变化,(,化学变化,),所致。,Thermosetplastics:It is one kind of plastic which after first time heating,it s structure will have chemical reaction.After cold and heat it again,It still wont be soft.,It is not reversible.,2,、热塑性塑料,(Thermoplastics),：指加热后会熔化，,可流动至模具冷却后成型，再加热后又会熔化的塑料：即可运用加热及冷却，,使其产生,可逆变化,(,液态固态,),，是所谓的物理变化。,Thermoplastics:After heating,it has,a physical change,So second time,heat the cold plastic,It still can be soft,it is reversible(liquidsolid),射出成型制程參數設定參考表,料,別,plastic name,烘料溫度,(,),Dry temperature,烘料時間,(,HR,),Dry time(hours),適當模溫,(,),Mould temperature,可塑化料溫,(,),Soft temperature,密度,(,g/cm,3,),density,收縮率,(%),Shrink percentage,PVC(S),6070,12,5070,140180,(1.5),PVC(H),6070,12,5070,150180,(1.40),(0.3),LOPE,7080,12,2050,160240,(0.92),(1.5),HDPE,70100,12,2070,200280,(0.96),(1.5),PP,7090,12,2050,200300,(0.90),(0.8),PS,7080,12,2070,180260,(1.05),(0.4),ABS,80100,12,4080,180260,(1.05),(0.6),AS,80100,2,4070,210260,(1.07),(0.4),PMMA,8090,3,5090,180250,(1.19),(0.4),EVA,4060,1,2055,130150,(0.93),(1.0),POM,80,2,40120,185230,(1.40),(1.8),PA,70,4,40,260290,(1.04),(0.4),MPPO,70100,24,60120,220300,(1.06),(0.6),PC,120,24,80100,270310,(1.20),(0.6),PET,130,4,60100,250280,(1.33),(0.3),PBT,130,34,6090,230260,(1.30),(1.7),PSU,160,3,120160,320360,(1.25),(0.7),PPS,130,13,120160,290330,(1.35),(1.1),PES,180,3,140180,340390,(1.37),(0.8),PEEK,150,3,130170,350400,(1.30),(1.1),ABS/PC,100,2,6090,240270,(1.18),(0.6),備注,:,1.,因各機台規格間差異較大,本表數值僅做參考,;,Eject reference parameters form,Each injection machine is different,above data just for you reference.,由于收缩率不是一个定值，而是一个范围，在制造模具时，,型腔则按照下偏差加工，型芯则按上偏差加工,，便於必要时可作适当的修整。,对於成形件壁厚来说，一般由於厚壁的冷却时间较长，因而收缩率也较大，从熔料流动距离来看，远离浇口部分的压力损失大，因而该处的收缩率也比靠近浇口部位大。因加强筋、孔、凸台和雕刻等形状具有收缩抗力，因而这些部位的收缩率较小。,浇口形式对收缩率也有影响。用小浇口时，因保压结束之前浇口即固化而使塑件的收缩率增大。注塑模中的冷却回路结构也是模具设计中的一个关键。冷却回路设计得不适当，则因塑件各处温度不均衡而产生收缩差，其结果是使塑件尺寸超差或变形。在薄壁部分，模具温度分布对收缩率的影响则更为明显。,Shrink percentage isnt a,constant value but in a range.,When you manufacture a mould,The cavity insert should use minus tolerance,core,insert use plus tolerance,so as to adjust if needed.,The thick wall part would be use more time for cold,So shrink percentage is bigger.,The position which is far away from injection gate,The force will be lost more,So shrink percentage is bigger.,The part which has rib,hole,boss,text,the,So shrink percentage is smaller.,The gate will affect shrink too,When you use small gate,The gate will be closed before keeping pressure finished,So shrink percentage is bigger.,The cooling system is also a key affect element.If lot of area of product temperature isnt even,each area shrink will be different too,It will result in bad dimension and deformation,especially for thin product,The affection will be more obviously.,塑胶件产品设计应注意如下：,Plastic product design should pay attention to below:,1,设计足够的脱模斜度，一般,1130,，产品越深，脱模斜度越大。,通常每增加,0.001,英寸之深度，须要增加,1,度额外之倾斜角。,1,Design enough draft angle,Normally 1130,The depth is deeper,the draft angle is bigger,Usually add 0.001 inch depth,We should add 1 for draft angle.,改進設計,Improved,原設計,Original,2,產品壁厚均勻,2,The thickness should be even,差,Poor,較好,Better,最好,Best,4,肋的厚度以底板厚度的,50%,為宜,甚至可以更薄,.,Rib thickness had better equal 0.5t or less.,3,切莫将产品设计成具尖锐的边角，因为其刻痕,(notch),状会造成应力集中，以致减少了产品之抗冲击力。,塑件有圆角，有利于塑料的流动充模及塑件的顶出，塑件的外观好，有利于模具的强度及寿命。,为了增加边角的强度及增进充模的能力，半径必须在壁厚的,25,到,75,之间，通常为,50,3,Never design sharp edge for plastic product,Because the notch will result in focus strength which will decrease the resistance ability.,The corner will good for running and ejection,The appearance is beautiful,and good for mould strength and lifetime.The corner always equal to 0.250.75t,0.5t is common use.,5,浮凸物,(bosses),：,浮凸物之目的是用来连接组合螺丝钉、导销、栓或迫紧,(force-fits),等作用。设计浮凸物的最重要原则为避免其无支撑物，并尽量让其与外壁或肋相连,Bossed is use for connect to screw,guide pin,bolt,force-fit and so on.,The design rule is:prevent the boss without support.Try to connect it to the wall or rib.,如果浮凸物本身与外壁间隔相当远，则最好加上角板,If boss is far away from the wall,It is better to add ribs,肋靠近浮凸物的设计,When the rib close to boss,6,孔（槽）,hole,塑件的孔三种成型加工方法：,3 ways for make the hole for plastic product,（,1,）模型直接模塑出来。,1,Come from mould,directory,（,2,）模塑成盲孔再钻孔通。,2,Blind first and then drill,（,3,）塑件成型后再钻孔。先模塑出浅孔好。,Drill directory,1,、模塑通孔要求孔径比（长度与孔径比）要小些，当孔径,1.5MM,，由于模芯易弯曲折 断，不适于模塑 模塑型芯的三种方式。,When the through hole need come from the mould,The hole diameter should more than 1.5mm and not so deep,otherwise core insert easy be broken down.,2,、肓孔的深度：,h,（,35,）,d,blind depth,d,1.5,时，,h,3d,3,、异形孔（槽）设计,special shape hole,塑件如有侧孔或凹槽，则需要活动块或抽芯机构,平行射成原则,确定塑件侧孔（槽）是否适合于脱模。,If the side face of the product has hole or groove,the mould need design the slide and make sure it is slide smoothly.,7,塑胶件加工花纹方法：电火花加工，照像化学磨蚀，雕刻冷挤压。,Plastic texture manufacture:,electric spark machining,photographic chemical erosion,carving cold extrusion,The end.,Any question?,