排氣 Vent 為何排氣仍然還是一個問題？ Why venting is still a problem ?

Presentation on theme: "排氣 Vent 為何排氣仍然還是一個問題？ Why venting is still a problem ?"— Presentation transcript:

1 排氣 Vent 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 and give the trapped air more time to escape. But ...

2 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 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.

3 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 are indications of flow problem in the filling system.

4 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, which corrects many of the fill and warpage problems.

5 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.

6 流道排氣 Runner Vents 深度(depth) : 寬度(width) :
mm易流塑料(easy-flow mat.) 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)

7 分模面排氣 Parting Line Vents 深度(depth) :
參照廠商建議 (refer to manufacturer’s recommendation) 寬度(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)

8 分模面排氣 Parting Line Vents

9 Ejector and Core Pin Vents
頂出銷或心型銷排氣 Ejector and Core Pin Vents 深度(depth) : 參照廠商建議 (refer to manufacturer’s recommendation) 寬度(width) : 全圓周長 (whole perimeter) 長度(length) : 1.5mm 排氣溝(vent groove): 1mm深 (deep)