中文摘要 隨著科技的進步,製程技術突破尺寸的限制、產品精密化、微型化及量產速度,為了符合產品的要求,提高模具溫度為最有效的方法之ㄧ。利用合模式氣體加熱模溫控制系統快速提高模面溫度,在充填時能使塑料有更好的流動性,以改善傳統射出成型品的成型品質問題。 本論文中,第一階段以合模式氣體加熱模溫控制系統針對其製程參數如氣體流量、加熱時間與加熱氣道間距對模溫影響性作一探討。第二階段以開模式氣體加熱系統與合模式氣體加熱系統進行加熱效益比較。同時利用CFD軟體分析與實驗比對加熱溫度場之結果,驗證製程之可行性。第三階段將合模式氣體加熱應用於微結構生物晶片、碳纖複合材料及玻璃纖維複合材料,探討此製程提升微流道轉寫性、碳纖複合材料導電性與降低浮纖現象。 研究結果顯示,在合模式氣體加熱製程中,當加熱時間越久、氣體流量越大,其加熱效益越高。而加熱氣道間距越大時,其溫差可由158℃降至65℃溫度分佈越均勻。使用開模式氣體加熱模溫控制將模溫從60℃加熱100℃、120℃與140℃分別需要12s、27s及83s。使用合模式氣體加熱模溫控制加熱至目標模溫只需1s、1.5s及2s,加熱速度約為40℃/s,由上述實驗結果顯示合模式氣體加熱在運用上之優勢。在CFD模擬分析結果中,其加熱效益與溫度分佈與實驗結果的趨勢相近,成功驗證製程的可行性。在案例中,成功提升微流道轉寫性17%,於碳纖複合材料上,降低平面電阻34%~43%與降低穿透電阻33%,有效提升導電性,並成功消除浮纖現象,證明此製程應用的高度潛力與可行性。
ABSTRACT In order to improve the quality requirements of the products, high mold temperature control technology provided the most effective way. Gas-assisted mold heating was used for rapid mold surface heating. Maintaining high mold temperature during the filling process is used to improve the polymer completely filling and reduce or eliminate many traditional molding problems. In this study, the model of gas-assisted mold heating is internal with mold temperature control system. The parameters of the process including gas flow rate, gap of air channel and heating time. The next, the heating efficiency is compared between internal and external of gas assisted heating method and using CFD-ACE analysis to simulate and verity the experiments result. Finally, the real injection molding combine with gas-assisted mold heating was used mold micro features, carbon fiber composite materials and glass fiber composite materials. As a result, with the increase of heating time, the heating temperature is increase. With the increase of gas flow rate, the heating speed is increase. The larger gap of air channel could get the more uniform temperature distribution. Using external gas-assisted mold heating, it takes 12, 27 and 83seconds to increase the mold temperature from 60℃ to 100℃, 120℃ and 140℃, respectively. Using internal gas-assisted mold heating, it just needs 1, 1.5 and 2 seconds, respectively. The heating speed could reach 40 ℃/s. CFD software can successful establish mold temperature field analysis. In the real injection molding case can improve the replication accuracy (17%) in molding micro features and the part surface gross of molding carbon fiber composite materials and glass fiber composite materials. For molding carbon fiber composite materials, it also can lower in-plane conductivity 34% ~ 43% and lower through-plane resistance 33%. Hence, the experiment results show significant feasibility and high potential in injection molding application.