浇注系统设计

1、模具設計的優先順序模具設計的優先順序priorities of mold designpriorities 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)澆注系統設計的優先順序澆注系統設計的優先順序priorities of filling system designpriorities of filling system design產品設計 (part design)型

2、腔設計 (cavity design)澆口設計 (gate design)流道設計 (runner design)噴嘴設計 (nozzle design)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壁厚不均是注塑成型中最大的麻煩製造者。 這對薄壁產品尤然。 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 bi

3、ggest 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 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

4、設計wall thickness designwall thickness design差 poor較好 better最好 best掏空設計掏空設計 (1) (1) coring out design (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) (2) coring out design (2)coring out design (2)氣泡或氣泡或/ /和凹陷的形成和凹陷的形成void or/and sink mark formingvoid or/and sink mark fo

5、rming氣泡氣泡 ( void )凹陷凹陷 ( sink 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 radiusthe effect of rib thickness & fillet radius肋的底部厚度肋的底部厚度bottom thickness of ribbottom thickness of ribw0.5w2.5ww1.2wd1.5wd(a)(b)肋的設計肋的設計 (1 )(1 )rib design ( 1 )rib design ( 1 )t = wall thichn

6、essb = 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.fbdect 肋的設計肋的設計 (2)(2)rib design ( 2 )rib design ( 2 )肋的設計肋的設計 (3)(3)rib design ( 3 )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 ( thermop

7、lastics )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 ( (熱塑性塑膠熱塑性塑膠) )boss away from wall ( thermopla

8、stics ) 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 outside boss aaa ( dia )bb = ab= 2a

9、( max. )section a-aeimr1where 1/r : 樑的曲率 curvature of the 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 rigidityflexural rigiditya variety of molded-in

10、interlocks can add stiffness to thin-wall housing designs.各種一體成型的內鎖件能增加薄殼的剛性。結構設計是薄殼成型零件的基礎。structural design is the base of thin-wall molding parts.薄殼成型產品不僅僅是一趨勢，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 a trend but also an effective way to achieve cost reduction and competitiveness in

11、crease.結構設計和薄殼成型產品結構設計和薄殼成型產品structural design & thin-wall molding partsstructural design & thin-wall molding parts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

12、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 can 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 valuesmaterialtypereinforcemen

13、ttypetensile strengthretention (%)pp0%gf86%pp20%gf47%pp30%gf34%san0%gf80%san30%gf40%pc0%gf99%pc10%gf86%pc30%gf64%psf0%gf100%psf30%gf62%pps0%gf83%pps10%gf38%pps40%gf20%pa660%gf83-100%pa6610%gf87-93%pa6630%gf56-64%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積風積風air traps

14、air 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

15、, at least, one gate mark, more runner volume and more air traps 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，找出可以涵蓋最大產品面積的進澆位置。in order to reduce the number of gates, each gate shall be l

16、ocated at where the melt is able to cover maximum part area based on the largest melt flow length/thickness ratio.澆口數目澆口數目the number of gates the number of gates 充填均衡充填均衡flow balanceflow 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 same time.洗衣機圈板洗衣機圈板洗衣機圈板洗衣機圈板冷氣通風飾罩冷氣通風飾罩-

17、-原始設計原始設計air-conditioner grille - originalair-conditioner grille - original18 gatespressure: 76 mpa冷氣通風飾罩冷氣通風飾罩- -修正設計修正設計air-conditioner grille - revisedair-conditioner grille - revised8 gatespressure: 75 mpa分析結果比較表分析結果比較表comparison of analysis resultscomparison of analysis results十二澆口設計十二澆口設計12 ga

18、te design12 gate design原始設計original design電子零件置物箱材料 material：abs四澆口設計四澆口設計4 gate design4 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原始設計修正設計澆口數目124充填時間 (s)22最大射壓 (mpa)58.461.8鎖模力需求 (ton)950820產品重量 (g)41364136流道系統重量 (g)29498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

19、 to balance flow in a how to balance flow in a multi-cavity moldmulti-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。first, 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 i

20、n all branches.一排支流道之不平衡充填一排支流道之不平衡充填unbalancedunbalanced flow in a branchflow 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 branchbalanced flow in a branch全模具全模具(128(128模穴模穴) )之不平衡充填之不平衡充填unbalanced flow in a moldunbalanced flow in a mold全模具全模具(128(128模穴模穴) )平衡後之充填平衡後之充填balanced flow in a mo

21、ldbalanced 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 intersection.melt ” flipper ” melt ” flipper ” 導致平直產品的澆口設計導致平直產品的澆口設計gate de

22、sign for flat partgate design for flat part中心澆口center gate扇形澆口fan gate最壞的worst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 hesitationgate design to avoid hesitation澆口gate薄thin厚thick差的設計差的設計poor好的設計好的設計good薄thin厚thick澆口gate0.94秒時，遲滯現象在1.2 mm厚凸片處發生公稱厚度

23、公稱厚度 3.2 mm幫浦零件幫浦零件 (part, pump)塑料塑料 (polymer) : pom沒有遲滯現象沒有遲滯現象幫浦零件幫浦零件 (part, pump)塑料塑料 (polymer): pom澆口設計澆口設計( (避免凹陷和氣泡避免凹陷和氣泡) )gate design to avoid sink mark & voidgate design to avoid sink mark & void澆口gate澆口gate差的差的poor好的好的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 gatea

24、void 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 correctlyavoid 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 gateavoid 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

25、 gate properlyavoid jetting by profiling gate properly差的poor好的good幫浦零件幫浦零件(part, pump)塑料塑料(polymer): pom進澆處進澆處(polymer entrance)：澆口厚澆口厚(gate thickness) 1.2mm，模穴厚，模穴厚(cavity thickness) 3.2mm問題問題 (problem)：噴流噴流(jetting)poor design causing jettingpoor design causing jettingpart : handle, refrigeratorma

26、terial : absproblem: jetting mark gas pingate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,外側則因體積收縮造成凹陷痕跡閥澆口閥澆口valve gatevalve 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 hydra

27、ulic cylinder閥澆口閥澆口 (1)(1)valve gate ( 1 )valve gate ( 1 )全部閥澆口同時打開時之充填狀況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.閥澆口閥澆口 (2)(2)valve gate ( 2 )valve gate ( 2 )部份閥澆口延遲打開，改變充填模式部份閥澆口延遲打開，改變充填模式mold filling with delayed valve gate opening; filling

28、pattern, weld lines and air traps are changed.多澆口設計多澆口設計 multi-gate designmulti-gate design閥式澆口閥式澆口valve gatevalve gate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澆口種類澆口種類gate typesgate types矩形邊緣澆口設計矩形邊緣澆口設計rectangular edge gate designrec

29、tangular 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 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 pvch = n th = 澆口厚度( gate thick. in mm )t = 零件壁厚( wall thick. in mm )wtlh30anw 扇形澆口設計扇形澆口設計

30、fan gate designfan gate designl= 1.3mmw= 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 mmt= 零件壁厚 wall thick. in mm 30n h1 = n t h2 = wh1/d重疊式澆口設計重疊式澆口設計overlap gate

31、 designoverlap 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 gate thick. in mm = nt澆口長度 land length in mm t= 零件壁厚 wall thick. in mm 30n l1 = 0.50.75l2 = h+( w/2 )凸耳澆

32、口設計凸耳澆口設計tab gate designtab 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= 零件壁厚 wall thick. in mm 30nh1 = n th2 = 0.9 t針點澆口設計針點澆口設計pi

33、n gate designpin gate designl = 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 pvcdltd0.206n ta4潛伏式澆口設計潛伏式澆口設計subgate designsubgate

34、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 gate thick. in mm = ntt= 零件壁厚 wall thick. in mm 30n30 15 25剪切速率剪切速率shear rateshear rate剪剪 切切 應應 力力shear stress黏黏 度度viscosity

35、剪剪 切切 速速 率率shear rate剪切應力剪切應力shear stressshear stress水力直徑水力直徑 hydraulic diameterhydraulic diameterpadh4where is the hydraulic diameter 水力直徑 a is the cross-sectional area of the flow 流路斷面積 p is the wetted perimeter 濕周長hd水力直徑水力直徑 hydraulic diameterhydraulic diameter在不同剖面形狀，相同斷面積下之變化在不同剖面形狀，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)(1) runner sizing (1)runner sizing (1)d : 流道直徑 ( mm ) runner diameter in mmw: 下游塑膠重量 ( g )