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  • 學位論文

PP和PP玻璃纖維之微細發泡對共射產品品質之影響

Effects of PP and PP-GF Combinations on the Qualities of Microcellular Co-Injection Molded Parts

指導教授 : 陳夏宗

摘要


本研究將微細發泡射出成型結合共射出成型,形成新式微細發泡共射出成型。此技術利用共射出之外層,能完全包覆微細發泡成型較差的表面品質,但仍同時擁有微細發泡成型製程之優點,包含因共射增厚的實心外層改善了微細發泡成型產品的拉伸特性和鋼性。實驗中所採用的材料為PP和PP添加10wt%玻璃纖維,其中PP已在各大產業廣泛應用,如汽車工業。此新技術既能減少PP產品的重量,增強其韌性,又能同時保有原鋼性,其添加之玻璃纖維則能提升產品的拉伸和彎曲強度。 研究中,利用不同的材料組合(共10種)分別作傳統射出成型、微細發泡成型、共射出成型與微細發泡共射出成型,針對產品的物理性質、表面品質和拉伸特性進行比較,結果顯示PP/PP-GF之微細發泡共射出成型為最佳化選擇。然而出乎意料地,PP-GF的強度約低於PP 20.8%,從材料的溶膠流動指數(Melt Flow Index, MFI)可發現,前者高於後者42.4%,證實在初期混料時強度就已有衰減的情形。 整體而言,PP/PP-GF之微細發泡共射出成型的產品重量(5.5082g)相對於同材料之共射出者減少4.2%,且相較於PP-GF之MuCell者,其外觀面的表面光澤度提升46.7%,高達60.9GU,而降伏強度和楊式係數則分別改善18.2%和2.5%,但其應變僅有0.084。另外在平均厚度均勻性上,微細發泡共射出產品相對於共射出成型、傳統射出成型和微細發泡成型者,分別大幅提升了61.0%,55.7%,和18.8%。雖然微細發泡共射出已成功提升了產品性能,但目前在實驗上仍有銀紋的問題,因此未來可針對如何提高孔隙的大小和分佈來改善表面缺陷作進一步之探討。

並列摘要


This study combined Microcellular Injection Molding (MuCell) with co-injection molding, becoming a novel technology: microcellular co-injection molding. A solid skin layer encases completely the poor surface of MuCell part while maintaining the renowned benefits of the MuCell part. It also thickens part solid cross-section area which is supposed to improve MuCell part tensile properties and stiffness. Furthermore, this study used both PP and PP-10-wt%-GF. PP itself has a wide-range applications, for instance, in the automotive field. This technology can reduce the PP part weight and enhance part toughness while maintaining part rigidity at the same time. The addition of GF is believed to reinforce further the tensile and flexural strength. In this study, conventional, MuCell, and co-injection moldings were also processed for relevant comparators. All injection molding parameters, were designated as constants, while material combinations were designated as variables (ten in total). The results of specific physical properties, surface qualities, and tensile properties show that microcellular co-injection molded PP/PP-GF is the optimal option. The only issue is that PP-GF unexpectedly bears 20.8% weaker strength than PP; its MFI is proven 42.4% higher, indicating that strength degradation is suspected to first happen during the melt-GF compounding. After all, microcellular co-injection molded PP/PP-GF yields 5.5082-g part weight (4.2% weight reduction over co-injection PP/PP-GF), fairly improved average thickness uniformity (61.0%, 55.7%, and 18.8% over co-injection, solid, and MuCell parts, respectively), proven resemblance in surface appearance and comparable surface gloss of 60.9 GU (46.7% higher than MuCell PP-GF) to its solid counterpart, improved yield strength by 18.2% and Young’s modulus by 2.5% over MuCell PP-GF, but extremely short strain at break of only 0.084 mm/mm. Equally important, later research can note how to improve cell size and distribution and solve silver streaks contamination occurring in this current study.

參考文獻


Process, Dissertation, Zhong Li: Chung Yuan Christian University, 2006.
Characteristics and Mechanical Properties of Injection-molded Foaming
Parts Using Induction Heating Technology," Advances in Polymer
[56] S. C. Chen, "Effects of Process Conditions on the Mechanical Properties of
[98] Y. Zhang, H. Li and S. Hwang, "Surface Defects and Morphology of

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