氣體反壓穩壓建置應用於超臨界微細發泡射出成型影響性之研究

現今塑膠產業中，超臨界微細發泡射出成型製程(Microcellular Injection Molding, MuCell®)是具有發展性的綠色能源技術，此製程具備節省能源、環境友善、縮短循環周期和降低成本等優點，因此在各項領域廣泛應用此技術進行生產產品；但是MuCell®製程中，泡體尺寸差距甚大導致泡體均勻性較差，進而影響產品的機械性質。在過往研究中使用氣體反壓控制技術(Gas Counter Pressure, GCP)，雖然氣體反壓有效控制充填階段的發泡行為，但是在充填時模穴內部的反壓壓力超出原本所設定數值，使泡體均勻性會下降，因此，本研究會在氣體反壓技術上建置穩壓設備，並去探討在有穩定反壓壓力與無穩定反壓壓力參數影響。本研究透過使用穩定氣體反壓技術可以去改善泡體的均勻性，再經由SEM截面圖觀察泡體平均直徑、泡體密度及泡體直徑標準差探討氣體反壓壓力、射出速度和洩氣速度對泡體結構影響，並找出最適合的最佳參數組合，結果顯示有穩定反壓壓力相較於無穩定反壓力泡體密度提升約41%，且泡體直徑標準差由2.54µm降低至1.77µm，實現整體泡體均勻度上升。

關鍵字

超臨界微細發泡射出成型；泡體均勻度；氣體反壓參數；穩定反壓壓力

並列摘要

In the current plastics industry, Microcellular Injection Molding (MuCell®) is a developmental green energy technology. This process has the advantages of saving energy, being environmentally friendly, shortening the cycle time, and reducing costs. Therefore, This technology is widely used in various fields to produce products; however, in the MuCell® process, which affects the performance of the product is cell uniformity. In previous studies, Gas Counter Pressure (GCP) was used. Although the GCP effectively controls the foaming behavior during the filling stage, the back pressure inside the cavity during filling exceeds the originally set value, causing the foam The uniformity of the body will decrease. Therefore, this research will build a pressure stabilizing device on the GCP technology, and explore the influence of the parameters of stable GCP and unsteady GCP. In this study, the uniformity of the bubble can be improved by stable GCP technology, and then the average bubble diameter, bubble density, and standard deviation of the bubble diameter are observed through SEM cross-sectional images to explore the relationship between the GCP, injection velocity, and deflation velocity. The bubble structure is affected, and the most suitable combination of parameters is found. The results show that the density of the bubble with stable GCP is increased by about 41% compared with that without stable GCP, and the standard deviation of the bubble diameter is reduced from 2.54µm to 1.77 µm, to achieve an increase in the uniformity of the overall bubble.

並列關鍵字

Microcellular Injection Molding ； Cell Uniformity ； GCP Parameter ； Stable GCP

參考文獻

1. J. R. Jambeck, A. Andrady, R. Geyer, R. Narayan, M. Perryman, Siegler, T., Wilcox, C., Lavender Law, K. Plastic waste inputs from land into the ocean, Science, 347, p. 768-771 (2015)