快速時序閥澆口系統應用於薄殼射出成型之探討

Study of Fast-Response Sequential Valve Gate System for Thin-Wall Injection Molding

楊庭杰(Ting-Chieh Yang)

指導教授 ： 陳夏宗 ； 張永鵬

中原大學/工學院/機械工程研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200499

摘要

中文摘要
本論文探討時序閥澆口應用於薄殼射出成型的適用性。在射出充填時間極短的情況下，系統響應的快慢為應用成效最主要的議題。
首先以高壓氮氣作為驅動活塞之動力，運用Labview程式語言配合NI 6035E DAQ介面卡建立以PC為架構的快速時序閥澆口控制系統。並使用液氣壓模擬軟體HyPneu輔助系統設計、分析。
在澆口開啟反應時間的探討上，嘗試利用衝擊加速規感測器埋設於活塞蓋，利用感測器與電磁閥訊號分析系統響應。實驗針對四組活塞尺寸與三組管路設計配合不同氮氣壓力，在無、有熔膠阻力狀態下，量測活塞全行程所需要的時間。並且探討活塞等機構的加工精度對反應時間的影響。實驗結果顯示，經過修正後的系統在儲氣瓶的輔助下，利用150 bar 的高壓氮氣，澆口開啟反應時間於聚苯乙烯（PS）230℃可成型的融膠阻力下降低至12 ms。實驗也發現當活塞與氣缸接觸間隙愈小時，接觸面的加工精度對反應時間的影響愈大。
最後利用此系統應用於薄殼射出成型，成型一長寬：193 mm × 50 mm，厚度：1 mm的長方形薄件，充填時間0.41秒，探討不同充填模式的製程特性。比較單澆口、雙澆口同開與時序澆口模式在成型壓力、縫合線現象以及強度的改變。實驗結果顯示，時序澆口充填模式有多澆口的優點，縮小流動長度與厚度比值，降低了成型壓力。另外利用接力時序的方式充填模穴，消除了多澆口常見的縫合線現象，並且提高其抗拉強度。實驗結果與電腦模流分析預測作驗證比較。
綜合本研究的結果顯示，適當設計的快速反應時序閥澆口系統能減少薄殼射出成型時所遭遇的問題，提供較佳的充填控制，並且提高成品的機械強度。

關鍵字

閥澆口 ； 熱澆道

並列摘要

Abstract
The objective of this paper was to investigate a fast response sequential valve gate system for thin wall injection molding. A gas-driven valve gate control system with human-machine interface (HMI) using Labview software was established.
The monitoring system of valve-gate opening was built using shock accelerometer transducers. System response was analyzed based on the solenoid valve and shock accelerometer transducers signals. All design parameters including gas-valve response characteristics, tolerance between inner piston and cylinder and gas pressure on affecting valve-gate opening were investigated. The delay time of vale-gate shaft movement in a non-melt environment can be reduced to 8 mini-second and it increases to 12 mini-second in a melt-filled environment.
In this study, the method of experiment including single-gate, sequential gate and concurrent gates injection filling processing was utilized. The molded parts with 1 mm thickness were injection molded under different methods. Effects of processing conditions including injection pressure, filling time and valve open/close time on mechanical properties of thin wall parts were investigated. On the other hand, the weld line location and weld line strength were addressed. The experiment results were compared with the predicted results of CAE simulation software.
The results of this study show that a fast response sequential valve gate system will improve productivity and part quality in thin wall injection molding.

並列關鍵字

Valve gate ； Hot Runner

參考文獻

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