射出問題和解決對策(1)
射出問題和解決對策(1)
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一. Short shot 產品未完成 |
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Short shot occurs when insufficient material is enjected and can't completely fill cavities. |
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Short shot can be caused by machine, mold or material. |
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當射出的材料不足且無法完全填充型腔時,就會出現短射。短射可能是由機器、 模具或材料造成的。 |
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Possible Cause |
Correction action |
Melt temperature too slow |
Adjust melt temperature upward 提高料管溫度 |
Insufficient feed |
Increase shot size 增加原料用量 |
Short injection time |
Increase injection time 增長射出時間 |
Injection speed too slow |
increase speed 加快射出速度 |
Low mold temperature |
Increase mold temperature 增高模具溫度 |
Non-uniform cooling |
Check water throughtput and line layout 重整模具水管 |
Poor venting in the mold |
Adjust proper vent position or add vents 調整合適位置或加適度之排氣孔 |
Clogged nozzle |
Clean the nozzles 清洗阻塞 |
Feed material unbalanced |
Redesign correct gates position 重開模具溢口位置 |
Gate or spill hole too small |
Increase gate diameter 加大澆口或溢口 |
Inadequate lubricant for plastic |
Increase lubricant in material 酌加潤滑劑 |
Poor melt plastic flow |
Add lubricant or change plastic 酌加潤滑劑或更換使用原料 |
Damage on check ring |
Check and replace 拆除檢查修理 |
Non correct machine |
Use proper machine 更換適合的機器 |
二. Shrinkage / 縮水 |
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Shrinkage is the contraction of a plastic moulded component |
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as it begins to cool after the injection process |
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塑料成型部件開始冷卻後, 會發生收縮. 收縮比率應塑料而異, 設計模具時要考量之。 |
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Possible Cause |
Correction action |
Insufficient filling |
Increase filling vollume 增加原料用量 |
Injection pressure too low |
Raise injection pressures 提高射出壓力 |
Short injection time
射出時間太短
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Increase injection time 增長射出時間 |
Injection speed too fast |
Reduce speed 減少射出速度 |
Unbalanced feeding to gate |
Adjust gate positions or gate diameter 調整模具入口大小或位置 |
Clogged nozzle |
Clean the nozzles 清洗阻塞 |
Melt Temperature too high |
Reduce temperature 降低溫度 |
Insufficient cooling |
Add cooling time 酌延冷卻時間 |
Poor venting 排氣不良 |
Add vents on shrinking parts 在縮水處設排氣孔 |
Injection nozzle too small |
Replace larger diameter nozzle 更換較大規格料管 |
Insufficient pressusre holding time |
Increase holding time 延長保壓時間 |
Damage on check ring |
Check and replace 拆除檢查修理 |
Material too soft |
Change material 更換原料 |
Large shrinking rate |
Change material 更換原料 |
三. Parts Sticking 成品黏模 |
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When the mold is opened, the product get stuck to the mold, it cannot fall off |
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開模時,產品粘在模具上,不能脫落.
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Possible Cause |
Correction action |
Injection pressure too high |
Reduce injection pressures 降低射出壓力 |
Over filling |
Use release agent 使用脫模劑 |
Pressure holding too long |
Reduce injection time 減少射出時間 |
Injection speed too fast |
Reduce injection speed 降低射出速度 |
Melt material temperature too high |
Reduce material melt temperature 降低料溫 |
Unbalanced filling |
Adust gate hole diameter or posiiton 變更溢口大小或位置 |
Insufficient cooling time |
Increase cooling time 增加冷卻時間 |
Mold temperature too high or too low |
Adjust mold temperature 調整模溫 |
Undercuts in the mold |
Eliminate undercuts 修模具除卻倒角 |
Mold walls not smooth |
Polish mold walls 拋光模具 |