《塑膠模基礎(chǔ)知識(shí)》PPT課件.pptx

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1、C O N S U L T I N G Eject reference parameters form Each injection machine is different , above data just for you reference. C O N S U L T I N G & E N G I N E E R I N G由于收縮率不是一個(gè)定值，而是一個(gè)范圍，在制造模具時(shí)，型腔則按照下偏差加工，型芯則按上偏差加工，便於必要時(shí)可作適當(dāng)?shù)男拚?duì)於成形件壁厚來(lái)說(shuō)，一般由於厚壁的冷卻時(shí)間較長(zhǎng)，因而收縮率也較大，從熔料流動(dòng)距離來(lái)看，遠(yuǎn)離澆口部分的壓力損失大，因而該處的收縮率也比靠近澆口部位

2、大。 因加強(qiáng)筋、孔、凸臺(tái)和雕刻等形狀具有收縮抗力，因而這些部位的收縮率較小。 澆口形式對(duì)收縮率也有影響。用小澆口時(shí)，因保壓結(jié)束之前澆口即固化而使塑件的收縮率增大。 注塑模中的冷卻回路結(jié)構(gòu)也是模具設(shè)計(jì)中的一個(gè)關(guān)鍵。冷卻回路設(shè)計(jì)得不適當(dāng)，則因塑件各處溫度不均衡而產(chǎn)生收縮差，其結(jié)果是使塑件尺寸超差或變形。在薄壁部分，模具溫度分布對(duì)收縮率的影響則更為明顯。 Shrink percentage isnt a constant value but in a range.When you manufacture a mould,The cavity insert should use minus toler

3、ance, 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, t

4、ext, 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 sh

5、rink will be different too , It will result in bad dimension and deformation, especially for thin product,The affection will be more obviously. C O N S U L T I N G & E N G I N E E R I N G塑膠件產(chǎn)品設(shè)計(jì)應(yīng)注意如下：Plastic product design should pay attention to below:1,設(shè)計(jì)足夠的脫模斜度，一般1130，產(chǎn)品越深，脫模斜度越大。通常每增加0.001英寸之深度，

6、須要增加1度額外之傾斜角。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(jìn) 設(shè) 計(jì) Improved原 設(shè) 計(jì) Original2,產(chǎn) 品 壁 厚 均 勻2,The thickness should be even差 Poor較 好 Better最 好 Best C O N S U L T I N G & E N G I N E

7、 E R I N G4,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,切莫將產(chǎn)品設(shè)計(jì)成具尖銳的邊角，因?yàn)槠淇毯?notch)狀會(huì)造成應(yīng)力集中，以致減少了產(chǎn)品之抗沖擊力。塑件有圓角，有利于塑料的流動(dòng)充模及塑件的頂出，塑件的外觀好，有利于模具的強(qiáng)度及壽命。 為了增加邊角的強(qiáng)度及增進(jìn)充模的能力，半徑必須在壁厚的25到75之間，通常為503,Never design sharp edge for plastic product , Because the notch wil

8、l 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. C O N S U L T I N G & E N G I N E E R I N G5,浮凸物(boss

9、es)：浮凸物之目的是用來(lái)連接組合螺絲釘、導(dǎo)銷、栓或迫緊(force-fits)等作用。設(shè)計(jì)浮凸物的最重要原則為避免其無(wú)支撐物，并盡量讓其與外壁或肋相連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.如果浮凸物本身與外壁間隔相當(dāng)遠(yuǎn)，則最好加上角板If boss is far away from the wall,

10、It is better to add ribs 肋靠近浮凸物的設(shè)計(jì)When the rib close to boss C O N S U L T I N G & E N G I N E E R I N G6, 孔（槽） hole 塑件的孔三種成型加工方法： 3 ways for make the hole for plastic product（1）模型直接模塑出來(lái)。 1,Come from mould directory（2）模塑成盲孔再鉆孔通。 2,Blind first and then drill （3）塑件成型后再鉆孔。先模塑出淺孔好。Drill directory 1、 模塑通

11、孔要求孔徑比（長(zhǎng)度與孔徑比）要小些，當(dāng)孔徑1.5MM，由于模芯易彎曲折 斷，不適于模塑 模塑型芯的三種方式。 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時(shí)， h 3d 3、 異形孔（槽）設(shè)計(jì) special shape hole塑件如有側(cè)孔或凹槽，則需要活動(dòng)塊或抽芯機(jī)構(gòu)平行射成原

12、則確定塑件側(cè)孔（槽）是否適合于脫模。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,塑膠件加工花紋方法：電火花加工，照像化學(xué)磨蝕，雕刻冷擠壓。Plastic texture manufacture: electric spark machining, photographic chemical erosion , carving cold extrusion C O N S U L T I N G & E N G I N E E R I N G C O N S U L T I N G & E N G I N E E R I N G C O N S U L T I N G & E N G I N E E R I N GThe end.Any question?