本論文之研究主要在探討雙色射出成型製程對於不同熱塑性材料的翹曲和抗拉性質之探討,使用結晶性材料HDPE/PP、非結晶性材料ABS/PC、添加玻璃纖維HDPE+20%GF/PP+20%GF、ABS+20%GF/PC+20%GF結合為實驗設計及材料,並以兩種不同厚度之試片(3mm、2mm)經由一次一因子法實驗分析結果,探討不同製程參數下材料對於翹曲跟抗拉強度之影響,以及添加玻璃纖維後產品所做的變化,最後再以田口式實驗法將ABS/PC之實驗參數做一個完整的規劃,以找到相關製程參數下彼此之影響性。經由一次一因子研究中得知,翹曲值隨著熔膠溫度、射出速度、保壓壓力、模具溫度提高而增加,而隨著冷卻時間增加而減少。在抗拉強度部份,則隨著熔膠溫度、射出速度、保壓壓力、模具溫度、冷卻時間提高而增加。而在ABS/PC結合試片田口翹曲實驗方面,冷卻時間為其最重要的影響因子,其次是模具溫度及熔膠溫度,結果得知以較長的冷卻時間、較低的模具溫度、以及較低的熔膠溫度,可以得到較低的翹曲值。而在玻璃纖維部份,添加玻璃纖維可以有效的降低產品的翹曲值,以及增加產品的抗拉強度。
This study investigated the effects of process conditions on the warpage of semi- crystalline and amorphous materials by over-molding process. HDPE/PP and ABS/PC materials are used for this study and processing parameters, like melt temperature, injection speed, packing pressure, cooling time, and mold temperature, are changed to study the effects on the warpage of the over-molding process. The top-bottom configuration of tensile bar is set for the over-molding process. The results showed that HDPE/PP has warpage value from 10.26 ~ 12.98 mm while ABS/PC has value from 3.70~10.05 mm. However, HDPE/PP both with 20 wt% glass fiber has warpage value from 3.83~5.66 mm. It showed that amorphous material (ABS/PC) has less warpage than that of semi-crystalline (HDPE/PP) and material with glass fiber also reduced the warpage of the molded parts. The warpage value increased as the melt temperature, injection speed, packing pressure, and mold temperature increased. However, warpage value reduced as the cooling time increased. The tensile strength increased as the melt temperature, injection speed, packing pressure, mold temperature, and cooling time increased. The Design of Experiment(DOE) showed that the critical factors to affect the warpage value are cooling time, mold temperature, and melt temperature accordingly.