- 學位論文
尼龍塑料射出成型過程模具溫度對模具頂出間隙影響之研究
Study on The Mold Temperature Effect on Ejection Pin Gap in Nylon Injection Molding Process
摘要
本研究乃針對產業之輕薄化、低耗能之發展趨勢下， 模具製造與射出成型也需同時搭配其高流動性、高模溫、高料溫之製程需求。而模具設計、製造加工和後端組配合模與射出成型製品生產良率息息相關，一般模具在合模組配時往往在常溫環境下進行，模具的頂出系統，例如頂針、頂出套筒等機構得以順暢、確實的做動，一旦將模具溫度長時間維持在高溫狀態下，將使模仁與頂出系統產生熱膨脹致使模具發生磨損、作動不順暢、干涉等問題。 本研究中首先利用六種不同組配間隙0.003mm、0.005mm、0.010mm、0.023mm、0.030mm、0.040mm 之頂針搭配尼龍塑料，分別於五種不同模具溫度60℃、80℃、100℃、120℃、140℃條件下做連續模次射出成型，以得到不同組配間隙之頂針在不同模具溫度條件下的磨耗情形。之後再利用電腦輔助分析做熱變形、充填分析與實驗結果相互驗證。 研究結果顯示，當模具溫度愈高頂出組配間隙過小時；頂出系統容易產生干涉咬死的現象，而組配間隙過大時則容易產生毛邊的問題。且以尼龍塑料而言模具溫度在100℃以下最適宜頂出系統之組配間隙為0.005mm~0.03mm 之間，當模具溫度 為140℃時最適宜頂出系統之組配間隙為0.01mm~0.023mm 之間。
並列摘要
In order to help the melt flow and eliminate the weld line, the mold temperature will be increased to have good quality parts. The mold temperature becomes an important issue for the plastic injection molding,especially for the thin and high gloss parts. Also, the mold design has great effect on part quality and manufacture efficiency. In general, the mold is made and assembled in room temperature. The ejection system can move smooth when mold assembling. During the injection molding,the mold temperature will higher then room temperature to help the melt flow and the mold will has thermal expansion and deformation. Than the ejection pin and mold insert will sometimes crash each other and have the wear problem. In this study, there are six gap designs 0.003mm、0.005mm、 0.010mm、0.023mm、0.030mm、0.040mm and five mold temperature 60℃、80℃、100℃、120℃、140℃ have been apply to find the gap design effect between ejection pin and mold insert with nylon resin. Besides, the thermal expansion and melt flow have been simulated to show the gap design result. It was found that the higher mold temperature and smaller gap design will easily to have the crash and wear problem. But the oversized gap design will have the flash issue. For the nylon resin, the gap design is from 0.005mm to 0.03mm and 0.01mm to 0.023mm when the mold temperature is 100℃ and 140℃ respectively.