局部射出壓縮應用於厚薄不均元件成型之探討

A Study on Local Compression for Injection Molding of Parts with Non-Uniform Thicknesses

林鈺傑(Yu-Chieh Lin)

指導教授 ： 楊申語 ； 林震

國立臺北科技大學/機電學院/精密機構設計產業研發碩士專班/碩士(2008年)

摘要

射出壓縮成型已應用於成型厚度平均的製品上，當成型厚薄不均的元件時，在同樣的壓縮行程，厚端被壓縮比例比薄端壓縮比例少，因厚薄兩端的差異而影響成型品質。本研究探討局部射出壓縮成型(LICM)製程，希望以改善厚薄不均之厚肉部成型能力。
本實驗設計局部射出壓縮機構為推頂器，針對不同厚肉部高度施以局部的後壓縮行程。比較傳統射出(IM)及局部射出壓縮成型(LICM)兩種成型方式對厚薄不均元件之表面凹陷及應力光彈等之間的差異，並探討製程參數對品質的影響。
由實驗結果得知局部射出壓縮成型表面凹陷值明顯低於傳統射出成型，四種不同厚肉部之厚薄不均元件的表面凹陷率，以厚肉部5 mm為最低，其次依序為2 mm，高度為3 mm及5 mm兩者成型效果皆最差。光彈殘留應力檢測結果發現，經由局部射出壓縮成型所得到之成品應力條紋分布對稱性較佳，但其應力條紋並未因LICM製程而減少。

關鍵字

局部射出壓縮 ； 厚薄不均

並列摘要

The injection compression molding has been successfully applied to produce parts of super-precision. However, for parts with non-uniform thickness, uniform-distance compression yields non-uniform compression ratio, resulting in different shrinkages in thick and thin sections respectively. This research is devoted to investigating the local compression for injection molding of parts with non-uniform thincknesses. The so called "Local Injection Compression Molding (LICM)" process is used to injection molding parts with thick and thin sections with compression applied to the thick sections.
The mechanism of compression in LICM is controlled by ejector compression system and tuned to compress the local thicknesses during post-filling process. The parts with non-uniform thickness molded are molded with injection molding(IM) and local injection compression molding(LICM). Their quality compared by the depth is the shinkmarks on surface and birefringence of residual stress.
Much less shinkmark depth is observed in parts with non-uniform thickness plate molded with LICM than that with IM. The results of the birefringence in parts molded with LICM have better symmetry. However, no significant reduce in the residual stress is observed in parts molded with LICM.

並列關鍵字

Local Compression for Injection Molding ； Non-Uniform Thicknesses

參考文獻

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