模具溫度控制對射出成型精度之影響

Abstract

非均一厚度成型品在射出成型的技術上，容易因為厚度的不均勻而造成冷卻收縮不平均，使成型品的尺寸精度控制不佳，影響使用的性能。本研究擬藉由射出成型實驗及Moldex3D模擬，分析熱塑性非結晶性高分子材料－壓克力（PMMA）、熱塑性半結晶性高分子材料－聚丙烯（PP）、耐龍（PA）在不同模具溫度條件下的成型品收縮與變形量。 本研究的非均一斷面成型品尺寸長、寬、厚度變化尺寸為70㎜ × 44㎜ × 1㎜ ~ 2㎜，採用最佳化的保壓壓力、鎖模壓力、塑料溫度、射出壓力、冷卻時間等進行射出成型，僅改變模具溫度變化為30℃、50℃和80℃的條件下進行分析，使用INSIZE 2103-10數位式指示量表（精度0.001㎜）測量三種溫度條件下的壓克力（PMMA）和聚丙烯（PP）、尼龍（PA）的成型品，將數據整理之後比較縮水率、計算各部位實際厚度差異，最後得到非均一厚度成型品的最佳溫度控制方式。

In the thickness molded product of the non-uniform injection molding technology, the cooling contraction of the uneven thickness molded is not uniform. So the dimensional accuracy of the molded is poorly controlled. In this study, the non-crystalline polymer material-Acrylic (PMMA), the semicrystalline thermoplastic polymer material-polypropylene (PP), the Nylon (PA) molded shrinkage and the deformation of the mold were conducted the injection molding experiments and Moldex3D simulation, that were under different temperature conditions. The non-uniform cross-section molded dimension length of the study, width and thickness dimensions is 70 mm × 44 mm × 1mm ~ 2mm. In the best packing pressure, clamping pressure, plastic temperature, injection pressure and cooling time of the injection molding objects, they just choose 30 ℃, 50 ℃ and 80 ℃ as the conditions of the mold temperature for analyzing. Using the INSIZE 2103-10 digital indication scale (accuracy of 0.001 mm) to measure the non-homogeneous molded product thickness of Poly methyl methacrylate (PMMA), polypropylene (PP) and Nylon (PA), the three mentioned temperature conditions were applied in the experiment. Finally, to achieve the best temperature control of the non-uniform thickness molded products, the Comparison of the shrinkage thickness between the amorphous and semicrystalline were conducted after the data processing.