塑胶产品与模具设计.ppt

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1、塑膠產品與模具設計塑膠產品與模具設計Plastic Part and Mold Design徐昌煜徐昌煜Charles Hsu歐磊科技股份有限公司歐磊科技股份有限公司OLE Technology Corp.模具設計的優先順序模具設計的優先順序Priorities of Mold Design澆注系統設計(Filling System Design)排氣系統設計(Venting System Design)冷卻系統設計(Cooling System Design)脫模系統設計(Ejecting System Design)澆注系統設計澆注系統設計Filling System Design徐昌煜C

2、harles Hsu豎澆道Sprue主流道Main Runner成品Part澆口Gate冷料井Cold Slug Well支流道Branch Runner典型的澆注系統典型的澆注系統Typical Filling System澆注系統設計的優先順序澆注系統設計的優先順序Priorities of Filling System Design產品設計(Part Design)型腔設計(Cavity Design)澆口設計(Gate Design)流道設計(Runner Design)豎澆道設計(Sprue Design)噴嘴設計(Nozzle Design)壁厚不均是注塑成形中最大的麻煩製造者。這

3、對薄壁零件尤然。這些麻煩包括了遲滯現象、短射、凹陷、發赤、噴流、翹曲及長冷卻時間等；目前都可用CAE以直接或間接的方式預測。Non-uniform wall thickness is the biggest trouble maker in plastic injection molding.This is especially true to thin-wall part.The troubles,including hesitation,short shot,sink mark,blush,jetting,warpage and long cooling time etc.,can be

4、predicted,directly or indirectly,by using CAE.壁厚不均壁厚不均Non-uniform Wall Thickness壁厚設計壁厚設計Wall Thickness Design差 Poor較好 Better最好 Best掏空設計掏空設計(1)Coring Out Design(1)改進設計 Improved原設計 Original差 Poor改進 Improved掏空設計掏空設計(2)Coring Out Design(2)空洞或空洞或/和凹陷的形成和凹陷的形成Void or/and Sink Mark Forming空洞空洞(Void)凹陷凹陷(Si

5、nk Mark)肋厚和內圓角半徑的影響肋厚和內圓角半徑的影響The Effect of Rib Thickness&Fillet Radius肋的底部厚度肋的底部厚度Bottom Thickness of RibW0.5W2.5WW1.2WD1.5WD(A)(B)肋的設計肋的設計(一一)Rib Design(1)t=wall thichnessB=0.5tC=3 tAAD=2 BE=0.13 mm(radius)F=1.5-2 deg假如需要更大的強度假如需要更大的強度,可增加肋的數目可增加肋的數目If more strength is required,add additional ribs

6、.FBDECt 肋的設計肋的設計(二二)Rib Design(2)肋的設計肋的設計(三三)Rib Design(3)與側壁相連之凸轂與側壁相連之凸轂(熱塑性塑膠熱塑性塑膠)Boss at Wall(Thermoplastics)A=凸轂附著處壁厚凸轂附著處壁厚 wall thicknessB=凸轂外環直徑凸轂外環直徑 dia.of boss over radiiC=0.5 AD=2 BE=1 2 degF=0.13 mm(radius)G=DH=0.8 AI=A/4J=2 BK=0.3 1 JL=0.5 A LHAAKEIGJDAFCBSection A-A遠離側壁之凸轂遠離側壁之凸轂(熱塑性

7、塑膠熱塑性塑膠)Boss Away From Wall(Thermoplastics)A=凸轂附著處壁厚凸轂附著處壁厚 wall thicknessB=凸轂外環直徑凸轂外環直徑 (含底部修整圓弧半徑含底部修整圓弧半徑)dia.of boss over radiiC=0.5 AD=2 BE=1-2 degF=0.13 mm(radius)G=0.95 DH=0.3 G min.to G max.I=0.5 AHEFDFGCBAI外側凸轂外側凸轂Outside Boss AAA(DIA)BB=AB=2A(max.)Section A-AWhere 1/r:樑的曲率 curvature of the

8、 beamM:彎曲力矩 bending momentE :彈性模數 modulus of elasticityI :斷面積對中立軸的慣性矩 moment of inertia of the cross-sectional area with respect to the neutral axisEI :撓曲剛性 flexural rigidity撓曲剛性撓曲剛性Flexural RigidityNeutral Axis?10.8平板和肋板的比較平板和肋板的比較Comparison between Plain&Ribbed Plates和平板比，若基於相同的慣性矩(剛性)，肋板需料少了43%，I

9、/A卻增加了1.79倍。肋板的最大厚度減為平板的1/4，使得冷卻時間驟降15/16(94%)。Based on the same moment of inertia(stiffness),ribbed plate needs 43%less material but boost I/A by 1.79 times comparing with plane plate.The maximum thickness of ribbed plate is only 1/4 of plain plates;showing a dramatic cooling time reduction of 94%(

10、15/16).平板和肋板的比較平板和肋板的比較Comparison between Plain&Ribbed PlatesA variety of molded-ininterlocks can add stiffness to thin-wall housing designs.各種一體成形的內鎖件能增加薄殼的剛性。結構設計是薄殼成形零件的基礎。Structural design is the base of thin-wall molding parts.薄殼成形零件不僅僅是一趨勢，而且也是降低成本和提高競爭力的有效途徑。Thin-wall molding part is not only

11、 a trend but also an effective way to achieve cost reduction and competitiveness increase.結構設計和薄殼成形零件結構設計和薄殼成形零件Structural Design&Thin-wall Molding Parts每增加一個澆口，至少增加一條熔接線，同時增加一個澆口痕跡、增加流道的體積以及增加較多的積風。Every time one gate is added,one weld line,at least,one gate mark,more runner volume and more air tra

12、ps will be added.在型腔能夠完滿充填的前提下，澆口數目是愈少愈好。As long as the cavity is able to be filled appropriately,gates are the less the better.為了減少澆口數目，每一澆口應就塑流力所能及的流長/壁厚比之內，找出可以涵蓋最大零件面積的進澆位置。In order to reduce the number of gates,each gate shall be located at where the melt is able to cover maximum part area base

13、d on the largest melt flow length/thickness ratio.澆口數目The Number of Gates 熔膠波前推進熔膠波前推進Melt-Front AdvancementMelt-Front Advancement充填模式,積風和熔接線Filling Patterns,Air-Traps and Weld Lines Location熔接線熔接線Weld LinesWeld Lines材料 Material:PC-GF50原設計 Original更改設計 Revised更改澆口位置以重新定位熔接線更改澆口位置以重新定位熔接線Weld Lines C

14、an Be Relocated Weld Lines Can Be Relocated By Changing Gate LocationBy Changing Gate Location典型對頭熔接線伸張強度保留值典型對頭熔接線伸張強度保留值Typical Butt Weld Tensile Strength Retention ValuesTypical Butt Weld Tensile Strength Retention Values熔接線冷料井熔接線冷料井Weld Slug WellWeld Slug Well對頭熔接線 Butt weld熔接線冷料井Weld slug well積

15、風積風Air TrapsAir Traps排氣排氣VentVent大部份熱塑性塑膠Most ThermoplasticsA 0.08 mmB 3.18 mmC 12.7 mmD 0.25 mm耐隆和聚縮醛(POM)Nylon and Acetal(POM)A 0.04 mmB 3.18 mmC 12.7 mmD 0.25 mm進料流道Feed Runner塑膠成品Plastic PartAD排氣孔VentBSEC.A-ACAA充填均衡充填均衡Flow Balance熔膠波前於同一時間抵達型腔各末端。Melt front reaches the ends of cavity at the sam

16、e time.洗衣機圈板洗衣機圈板洗衣機圈板洗衣機圈板原始設計Original Design十二澆口設計十二澆口設計12 Gate Design電子零件置物箱材料 Material：ABS四澆口設計四澆口設計4 Gate Design修正設計Revised Design電子零件置物箱材料 Material：ABS電子零件置物箱四澆口電子零件置物箱四澆口和十二澆口設計比較表和十二澆口設計比較表如何快速平衡眾多模穴之流道如何快速平衡眾多模穴之流道How to Balance Flow In A Multi-cavity Mold首先調整一排支流道內之次支流道尺寸，使此支流道內之各模穴可平衡充填。F

17、irst,adjust runner size in one branch to make flow balanced in this branch.再調整各支流道前段之尺寸，使各支流道可平衡充填。Then,adjust the first sections runner size in each branch to make flow balanced in all branches.一排支流道之不平衡充填一排支流道之不平衡充填Unbalanced Flow In A Branch 一排支流道平衡後之充填一排支流道平衡後之充填Balanced Flow In A Branch全模具全模具(1

18、28模穴模穴)之不平衡充填之不平衡充填Unbalanced Flow In A Mold全模具全模具(128模穴模穴)平衡後之充填平衡後之充填Balanced Flow In A MoldThe melt fills the inside cavities before filling the outside cavities.The runner system shows that warmer,low-viscosity material(yellow and red)follows the inside wall when the melt splits at an intersecti

19、on.剪切速率剪切速率Shear Rate剪剪 切切 應應 力力shear Stress黏黏 度度viscosity剪剪 切切 速速 率率shear rate剪切應力剪切應力Shear Stress澆口種類澆口種類Gate Types針點澆口Pin Gate扇型澆口Fan Gate潛伏澆口Submarine Gate邊緣(薄膜)澆口Edge(Film)Gate凸片澆口Tab Gate閥澆口Valve Gate環狀澆口Ring Gate導致平直零件的澆口設計導致平直零件的澆口設計Gate Design for Flat Part中心澆口Center Gate扇形澆口Fan Gate最壞的Wors

20、t壞的Worse較好的Better最好的Best側澆口Edge Gate薄模澆口Film Gate澆口設計澆口設計(減少滯流效應減少滯流效應)Gate Design to Avoid Hesitation澆口gate薄thin厚thick差的設計Poor好的設計Good薄thin厚thick澆口gate0.94秒時，遲滯現象在1.2mm厚凸片處發生公稱厚度3.2mm幫浦零件(Part,Pump)塑料(Polymer):POM沒有遲滯現象幫浦零件(Part,Pump)塑料(Polymer):POM澆口設計澆口設計(避免凹陷和空洞避免凹陷和空洞)Gate Design to Avoid Sink

21、Mark&Void澆口gate澆口gate差的Poor好的Good使用重疊澆口以避免噴流使用重疊澆口以避免噴流Avoid Jetting by Using Overlap Gate差的Poor好的Good正確的澆口位置以避免噴流正確的澆口位置以避免噴流Avoid Jetting by Locating Gate Correctly差的Poor好的Good使用凸片澆口以避免噴流使用凸片澆口以避免噴流Avoid Jetting by Using Tab Gate使用適當的澆口形狀以避免噴流使用適當的澆口形狀以避免噴流Avoid Jetting by Profiling Gate Properly差

22、的Poor好的Good幫浦零件(Part,Pump)塑料(Polymer):POM進澆處(Polymer entrance)：澆口厚(Gate thickness)1.2mm，模穴厚(Cavity thickness)3.2mm問題(Problem)：噴流(Jetting)Poor Design Causing JettingGatePart :Handle,RefrigeratorMaterial:ABSProblem:Jetting Mark Gas Pin氣輔成型冰箱把手氣輔成型冰箱把手澆口及氣針入口澆口太小,導致噴流痕產生厚度差異過大,導致二次噴流痕產生R角過小,氣體通路接近把手內側,

23、外側則因體積收縮造成凹陷痕跡閥澆口閥澆口Valve Gate1.閥澆口梢 Valve-Gate Pin2.加熱管 Heater3.O型環#610 0 Ring4.流道歧管模板 Manifold Plate5.軸封環 Seal Retainer6.套筒軸封 Sleeve Seal7.枕塊 Support Pillar8.油壓缸 Hydraulic Cylinder閥澆口閥澆口(一一)Valve Gate(1)全部閥澆口同時打開時之充填狀況Mold filling with all the valve gates(shut-off gates)opened at the same time.閥澆口

24、閥澆口(二二)Valve Gate(2)部份閥澆口延遲打開，改變充填模式Mold filling with delayed valve gate opening;filling pattern,weld lines and air traps are changed.多澆口設計多澆口設計 Multi-Gate Design閥式澆口閥式澆口Valve Gate矩形邊緣澆口設計矩形邊緣澆口設計Rectangular Edge Gate DesignL=0.5 0.75 mmW=澆口寬度(mm)gate width in mmA=型腔表面積(mm2 )surface area of cavity i

25、n mm2n =材料常數 material constant 0.6 for PE,PS 0.7 for POM,PC,PP 0.8 for CA,PMMA,PA 0.9 for PVCh=n th=澆口厚度(gate thick.in mm)t =零件壁厚(wall thick.in mm)WtLh扇形澆口設計扇形澆口設計Fan Gate DesignL=1.3 mmW=w=澆口寬度 mm gate width in mmA=型腔表面積 mm2 surface area of cavity in mm2n=材料常數 material constant 0.6 for PE,PS 0.7 fo

26、r POM,PC,PP 0.8 for CA,PMMA,PA 0.9 for PVC澆口厚度 gate thick.in mmt=零件壁厚 wall thick.in mm h1 =n t h2=wh1/D重疊式澆口設計重疊式澆口設計Overlap Gate DesignW=w=澆口寬度 mm gate width in mmA=型腔表面積 mm2 surface area of cavity in mm2n=材料常數 material constant 0.6 for PE,PS 0.7 for POM,PC,PP 0.8 for CA,PMMA,PA 0.9 for PVC澆口厚度 gat

27、e thick.in mm=nt澆口長度 land length in mm t=零件壁厚 wall thick.in mm L1=0.50.75L2=h+(w/2)凸耳澆口設計凸耳澆口設計Tab Gate DesignL=0.50.75mmW=w=澆口寬度 mm gate width in mmA=型腔表面積 mm2 surface area of cavity in mm2n=材料常數 material constant 0.6 for PE,PS 0.7 for POM,PC,PP 0.8 for CA,PMMA,PA 0.9 for PVC澆口厚度 gate thick.in mm t

28、=零件壁厚 wall thick.in mm h1 =n th2 =0.9 tL=0.5 0.75 mmd=澆口直徑(mm)gate diameter in mmt =零件壁厚(mm)wall thick.in mmA=型腔表面積(mm2)surface area of cavity in mm2n=材料常數 material constant 0.6 for PE,PS 0.7 for POM,PC,PP 0.8 for CA,PMMA,PA 0.9 for PVC針點澆口設計針點澆口設計Pin Gate DesigndLt潛伏式澆口設計潛伏式澆口設計Subgate DesignW=w=澆口

29、寬度 mm gate width in mmA=型腔表面積 mm2 surface area of cavity in mm2n=材料常數 material constant 0.6 for PE,PS 0.7 for POM,PC,PP 0.8 for CA,PMMA,PA 0.9 for PVC澆口厚度 gate thick.in mm=ntt=零件壁厚 wall thick.in mm 30 15 25水力直徑水力直徑 Hydraulic DiameterWhere is the hydraulic diameter 水力直徑 A is the cross-sectional area

30、of the flow 流路斷面積 P is the wetted perimeter 濕周長水力直徑水力直徑 Hydraulic Diameter在不同剖面形狀，相同斷面積下之變化Various runner profiles,based on the same cross-sectional area流道尺寸設計流道尺寸設計(1)Runner Sizing(1)D:流道直徑(mm)runner diameter in mmW:下游塑膠重量(g)downstream plastic weight L:流道長度(mm)runner length in mm流道尺寸設計流道尺寸設計(2)Runn

31、er Sizing(2)流道尺寸設計流道尺寸設計(3)Runner Sizing(3)流道尺寸設計流道尺寸設計(4)Runner Sizing(4)流道尺寸設計流道尺寸設計(A1)Runner Sizing(A1)G:重量 weightS :零件厚度 thicknessD :參考直徑 reference diameterG(g)D(mm)for PS,ABS,SAN,CAB流道尺寸設計流道尺寸設計(A2)Runner Sizing(A2)G(g)D(mm)for PE,PP,PA,POMG:重量 weightS :零件厚度 thicknessD :參考直徑 reference diameter

32、流道尺寸設計流道尺寸設計(B)Runner Sizing(B)D:參考直徑 reference diameterL:長度 lengthfL:長度係數 Length coefficientD:流道直徑 runner diameterfLL(mm)D=D fL冷料井設計冷料井設計Cold Slug Well Design2d次流道Secondary runnerd主流道Primary runner澆口Gate型腔Cavity倒椎度冷料井豎澆道拉料桿Reverse taper cold slug-well sprue pullerZ型冷料井豎澆道拉料桿 Z-taper cold slug-well

33、sprue puller溝型冷料井豎澆道拉料桿Grooved cold slug-well sprue puller冷料井設計冷料井設計Cold Slug Well Design澆道襯套尺寸澆道襯套尺寸Sprue Bushing Sizing排氣系統設計排氣系統設計Venting System Design徐昌煜Charles Hsu為何排氣仍然還是一個問題？Why venting is still a problem?因為降低射速，讓積風有較多的時間逃氣，是一件太容易的事。但是Because it is too easy to slow down the injection speed an

34、d give the trapped air more time to escape.But.排氣排氣Vent射速一降，熔膠溫度很快降低，射壓必須提高，殘餘應力隨之提高，翹曲的可能性增加。如果想藉提高料溫，以降低射壓，料溫必須升得很高，這樣又會引起塑料裂解。When injection speed is lower,melt temperature goes down very fast,injection pressure has to be increased,residual stress is increased and the possibility getting warppage

35、 becomes higher.If one would like to increase barrel temperature to reduce the required injection pressure,the barrel temperature has to be increased to a quite high level and polymer degradation would be induced.排氣排氣Vent高料溫和高射壓都說明充填系統有了流動的問題Both high barrel temperature and high injection pressure a

36、re indications of flow problem in the filling system.排氣排氣Vent我們常發現:射速提高時，塑料表現得更為出色。It is quite common that material performs better when it is injected faster.最適化螺桿速度充分運用摩擦熱，將塑流保持在最佳狀態。許多充填和翹曲的問題也就迎刃而解。An optimized ram speed profile fully uses the friction heat to keep the best flow characteristics,

37、which corrects many of the fill and warpage problems.排氣排氣Vent有了適當的排氣，射速可以提高，充填和保壓可達良好狀態，不須過度增加料管和噴嘴的溫度。With proper venting,the injection speed could be increased to achieve good fill and pack conditions,without having to raise the barrel and nozzle heats,improperly.排氣排氣Vent深度(depth):1.0.075 mm易流塑料(e

38、asy-flow mat.)2.0.125 mm難流塑料(stiffer-flow mat.)3.深度深到流道末端見毛邊為準 (deep enough to feel flash at runner end)寬度(width):和流道同寬(as wide as runner dia.)排氣唇部(vent lip):1.5mm A1拋光(finish)排氣通道通大氣(vent channel to atmosphere):1mm深(deep)流道排氣流道排氣Runner Vents深度(depth):參照廠商建議(refer to manufacturers recommendation)寬度(

39、width):全圓周長(whole perimeter)or 5mm長度(length):1.5mm A1拋光(finish)排氣通道通大氣(vent channel to atmosphere):1mm深(deep)分模面排氣分模面排氣Parting Line Vents分模面排氣分模面排氣Parting Line Vents深度(depth):參照廠商建議(refer to manufacturers recommendation)寬度(width):全圓周長(whole perimeter)長度(length):1.5mm排氣溝(vent groove):1mm深(deep)頂出銷或心型

40、銷排氣頂出銷或心型銷排氣Ejector and Core Pin Vents冷卻系統設計冷卻系統設計Cooling System Design徐昌煜Charles Hsu模具冷卻設計的目的模具冷卻設計的目的Purposes of Mold Cooling Design1.均衡冷卻(改良產品品質)Even Cooling(Improve Part Quality)2.有效冷卻(提高生產力)Efficient Cooling(Increase Productivity)薄殼產品不像傳統壁厚者一般可以承受較大的因熱傳不均而產生的殘餘應力。為了將收縮彎翹控制在可以接受的程度，均衡的冷卻設計變得非常重要

41、。Thin-wall part can not afford as much thermal induced residual stress as the conventional one does.An even cooling design becomes very important to control the shrinkage and warpage at an acceptable level.冷卻設計冷卻設計Cooling Design射出成型週期時間射出成型週期時間Injection Molding Cycle Time充填時間Fill Time開模時間Open Time後充

42、填時間Post-fill Time對冰箱蔬果盤之類的大零件而言，材料往往佔成本50%以上。對小而薄的零件而言，成形機費用可佔成本的90%，材料6%，而模具只佔4%。小而薄的產品較之厚者更能從冷卻的改善而獲得效益。For larger molded parts,material typically represents more than 50%of the part cost for a refrigerator crisper tray.In the case of a thin-wall small part,the press cost could be 90%of the cost o

43、f the part;material constitutes 6%and the mold only 4%of the cost of each part.Small thin-wall parts typically benefit from improved cooling more than thick parts.冷卻設計冷卻設計Cooling Design典型的冷卻系統典型的冷卻系統Typical Cooling System模溫調節機Temperature controlling unit軟管Hoses冷卻迴路 2Cooling Circuit 2冷卻迴路 1Cooling Ci

44、rcuit 1泵Pump收集歧管Collection manifold供給歧管Supply manifold模具冷卻管路模具冷卻管路 Mold Schematic冷卻孔道冷卻孔道Cooling Channels入口Inlet出口Outlet出口Outlet入口Inlet噴泉管噴泉管Bubbler障板管障板管Baffle熱管熱管Heat Pipe蒸發部位熱輸入Heat In凝結部位熱輸出Heat Out液體Liquid蒸汽Vapor燈心(毛細管)Wick (Capillary)熱管的應用熱管的應用The Application Of Heat Pipe理論上最短冷卻時間理論上最短冷卻時間Min.

45、Possible Cooling Time理論上最短冷卻時間the min.possible cooling time產品最大厚度the max.part thickness熔膠的熱擴散度thermal diffusivity of the melt射出溫度injection temp.冷卻液溫度coolant temp.頂出溫度ejection temp.冷卻時間和厚度分佈冷卻時間和厚度分佈Cooling Time and Thickness Profile差的設計Bad Design好的設計Good Design冷卻孔道直徑、深度和節距建議值冷卻孔道直徑、深度和節距建議值Recommend

46、ed Diameter,Depth&PitchD:直徑為10至14mm Diameter of Cooling Channel,10 to 14 mmd:深度為D至3D Depth,D,to 3D P:節距為3D至5D Pitch,3D to 5D原始設計原始設計Original Design修正設計修正設計Revised DesignAASEC.A-A原始設計原始設計Original Design母模板Cavity Plate澆道襯套Sprue Bushing母模嵌塊Cavity Insert公模嵌塊Core Insert公模板Core Plate承板Support Plate修正設計修正設

47、計Revised Design母模板Cavity Plate澆道襯套Sprue Bushing母模嵌塊Cavity Insert公模嵌塊Core Insert公模板Core Plate承板Support Plate原始設計原始設計Original Design公模嵌塊core insertO型環O-ring空氣囊air pocket 修正設計修正設計(一一)Revised Design(1)公模嵌塊core insertO型環O-ring修正設計修正設計(二二)Revised Design(2)公模嵌塊core insertO型環O-ring不平衡的設計不平衡的設計Unbalanced Des

48、ign平衡的設計平衡的設計Balanced Design不用限流孔梢的內歧管設計不用限流孔梢的內歧管設計Internal Manifold Design without Frops使用限流孔梢的內歧管設計使用限流孔梢的內歧管設計Internal Manifold Design Utilizing Frops限流孔梢限流孔梢Flow Resistance Orifice Pin紊流和層流紊流和層流Turbulent and Laminar Flows紊流Turbulent Flow層流Laminar Flow雷諾數雷諾數Reynolds Number雷諾數(無因次)Reynolds number

49、(dimensionless)密度density(g/cm3)直徑diameter(cm)速度velocity(cm/sec)黏度viscosity(poise or dyne-sec/cm2 or g/cm-sec)Nu對雷諾數對雷諾數(Re)Nusselt Number Vs.Reynolds Number層流Laminar紊流Turbulent差的設計差的設計Poor Design好的設計好的設計Better Design差的設計差的設計Poor Design好的設計好的設計Better Design差的設計差的設計Poor Design好的設計好的設計Better Design冷卻設計

50、原則冷卻設計原則Cooling Design Principles選擇熱擴散係數大的塑料。Select Plastic Material with large thermal diffusivity.採用薄而均一的製件厚度。Use a thin and uniform part thickness.在型腔周圍均衡的配置冷卻孔道。Layout cooling channels around cavities evenly.在熱傳的道路上移除空氣間隙和空氣囊。Remove air gaps and pockets from heat transfer path.平衡冷卻液流動。Balance co