本研究以短玻璃纖維強化聚縮醛(POM/GF)複合材料為對象，探討不同射出成型參數如充填時間、融膠溫度、模具溫度與保壓壓力等對於纖維排向、拉伸性質與磨耗性質之影響。藉由田口實驗設計法、變異數分析及主成分分析法，進行POM/GF單一機械性質與多重機械性質之製程條件最佳化分析。同時，採用掃瞄式電子顯微鏡觀察纖維排列方向及破壞斷面型態。
研究結果顯示，在顯微組織方面，拉伸試片之橫截面可明顯分為表皮層與核心層兩區域，表皮層的纖維排向平行於融膠流動方向，核心層的纖維排向垂直於融膠流動方向。磨耗試片之橫截面可明顯分為表皮層、剪力層與核心層三個區域，表皮層與核心層的纖維排向垂直於融膠流動方向，剪力層的纖維排向則平行於融膠流動方向。
POM/GF複合材料之纖維含量愈高，其強度愈高且其摩擦係數也愈高。摩擦方向與融膠流向平行時(P方向試片)摩擦係數與磨耗體積損失比兩者垂直時(AP方向試片)來得稍低。對POM/25wt.% GF而言，射出成型條件為充填時間1.5 s、融膠溫度215℃、模具溫度75℃與保壓壓力75MPa時，具有最佳的拉伸性質與磨耗性質。
在破壞機構方面，拉伸試片表皮層主要破壞模式為纖維被拉斷及纖維被抽離基材，核心層之主要破壞模式為纖維與基材介面分離。不含纖維的POM主要破壞型態為凹坑與紋溝。POM/GF複材的主要破壞型態為紋溝、碎屑、裂縫及纖維脫離。
在POM/25wt.% GF複材製程最佳化方面，針對不同單一品質時，其最顯著之控制因子亦不同。若同時考量抗拉強度、伸長率及摩擦係數等三項機械性質之多重品質特性時，其最佳化射出成型條件為充填時間1.5 s、融膠溫度230℃、模具溫度60℃及保壓壓力75 MPa。此時，影響最顯著之控制因子為保壓壓力，其貢獻度為50.99%。

This study investigates the influence of injection molding process parameters on fiber orientation and mechanical properties of short glass fiber reinforced polyoxymethlene (POM/GF) composites. Filling time, melt temperature, mold temperature and packing pressure were considered as the controllable factors during the injection molding process. Taguchi experimental design, ANOVA analysis and principle component analysis were adopted in order to optimize the process conditions. Moreover, the fiber orientation and fracture surfaces were observed with a scanning electron microscope (SEM).
Two distinct layers existed in the cross section of the POM/GF tensile specimen. The fibers in the frozen layer were parallel to the tensile direction, while those in the core layer were perpendicular to the tensile direction. In addition, three distinct layers existed in the cross section of wear specimens. The fibers in the frozen and the core layer were perpendicular to the melt flow direction, but the fibers were parallel to the melt flow in the intermediate layer.
The tensile strength and friction coefficient increased with the amount of glass fiber. The friction coefficient and the wear volume loss also depended on the sliding direction. The specimen with sliding direction paralleling the melt flow had low friction coefficient and wear volume loss. To obtain the best tensile strength and tribological properties POM/GF composites, the injection molding conditions were as follows: filling time 1.5 s, melt temperature 215℃, mold temperature 75℃, and packing pressure 65 MPa.
Though the fiber-avulse and the fiber-snap were the major fracture mechanisms of frozen layer, the fiber-breakage and the pull-out were the major fracture mechanism of the core layer for the tensile specimens. In addition, SEM photographs revealed that peel-off and grooves were the major wear mechanisms of the neat POM. Grooves, debris, cracks and debonded fibers were the major wear mechanisms of the POM/GF composites.
With respect to the optimum injection molding process of POM/25wt.% composites, it was found that the most influential factor depended on the target mechanical property. For a multi-response case with the tensile strength, elongation, and friction coefficients (P-type), the optimal injection molding process conditions were filling time 1.5 s, melt temperature 215℃, mold temperature 75℃, and packing pressure 65 MPa. Moreover, the most influential factor was packing pressure, and its contribution was 50.99%.

參考文獻
1. 洪士淇，工程塑膠市場現況，工業技術研究院經資中心，2005.8。
2. J. Chen, Y. Cao, and H. Li, "Investigation of the friction and wear behaviors of polyoxymethylene/linear low-desity polyethylene/ethylene-acrylic-acid blends," Wear, Vol. 260, pp. 1342-1348, 2006.
3. K. Palanivelu, S. Balakrishnan, and P. Rengasamy, "Thermoplastic polyurethane toughened polyacetal blends," Polymer Testing, Vol. 19, pp. 75-83, 2000.
4. X. Hu, " Friction and wear behaviors of toughned polyoxymetrylene blend under water lubricanttion, " Polymer-Plastics Technology & Engineering, Vol. 39, 2000, pp. 137-150.
5. H. Benabdallah, "Friction and wear of blended polyoxymethylene sliding against coated steel plates," Wear, Vol. 254, pp. 1239-1246, 2003.
6. K. M. Tao, and D. H. Xiang, "Friction and wear behavior of POM filled with PTFE, glass fiber and graphite," Lubrication Engineering, pp. 103-105, 2006.
7. S. Hashemi, P. Elmes, and S. Sandford, "Hybrid effects on mechanical properties of polyoxymethylene," Polymer Engineering and Science, Vol. 23, pp. 45-58, 1997.
8. J. Kastelic, A. Buckley, and P. Hope, "Hydrostatic extrusion of glass reinforced and unreinforced celcon POM," Polymer Science and Technology, pp. 175-191, 1983.
9. S. Soundararajan, and S. C. Shit, "Studies on properties of poly olefins: Poly propylene copolymer (PPcp) blends with methylenes (POM)," Polymer Testing, Vol. 20, pp. 313-316, 2001.
10. G. F. Wilson, D. J. Keller, and Y. Eckstein, "Effects of molding parameters on the properties of short glass fiber-reinforced TPUs.," Automotive Challenge and Plastics Response: Automotive Plastics. RETEC’87; Dearborn, MI, USA, 1987.
11. P. F. Bright, and M. W. Darlington, "Factors influencing fibre orientation and mechanical properties in fibre reinforced thermoplastics injection moldings," Practical Rheology in Polymer Process; Computers & Tensile Properties of PBT 61 Chemical Engineering International Conference. Loughborough, England, 1980.
12. S. F. Xavier, D. Tyagi, and A. Misra, "Influence of injection-molding parameters on the morphology and mechanical properties of glass fiber reinforced polypropylene composites," Polymer Composites Vol. 3, pp. 88-96, 1982.
13. S. E. Barbosa, and J. M. Kenny, "Analysis of the relationship between processing conditions-fiber orientation-final properties in short fiber reinforced polypropylene," Journal of Reinforced Plastics and Composites, Vol.18, No.5, pp. 413-420, 1999.
14. U. Delpy, and G. Fischer, "Effect of mold-filling conditions on fiber distribution in injection-molded disks and on the mechanical properties of such disks," Advanced Polymer technology, Vol. 5, pp. 19-26, 1985.
15. M. Gupta, N. Santhanam, H. H. Chiang, K. Himasekhar, P. Tushak, and K.K. Wang, " Prediction of fiber orientation and mechanical properties in short-fiber-reinforced injection-molded composites," The 3rd International Conference on Computer Aided Design in Composite Material Technology. Newark, DE, USA, 1992.
16. M. Damle, S. Mehta, R. Malloy, and S. P. McCarthy, "Effect of fiber orientation on the mechanical properties of injection molded part and a stereolitho graphy-insert molded part," Proceedings of the 56th Annual Technical Conference. Atlanta, GA, USA, 1998.
17. A. Gennaro, "Glass reinforced polyamide injection moulded: fibre orientation effects on properties," Plastic & Rubber Processing and Applications, Vol. 9, pp. 241-250, 1988.
18. F. Lumini, and A. Pavan, "Short fibre composite materials: relationship between fibre orientation and fracture toughness," Plastic & Rubber Processing and Applications, Vol. 27, pp. 240-246, 1998.
19. N. M. Neves, G. Isdell, A. S. Pouzada, and P. C. Powell, "On the effect of the fiber orientation on the flexural stiffness of injection molded short fiberreinforced polycarbonate plates," Polymer Composites, Vol. 19, pp. 640-651, 1998.
20. A. Siegmann, A. Buchman, and S. Kenig, "Residual stress in polymers III: the influence of injection-molding processes conditions," Polymer Engineering and Science, Vol. 22, pp. 560-568, 1982.
21. W. E. Haskell III, S. P. Petrie, and R. W. Lewis, "Fracture toughness of a short-fiber-reinforced thermoplastic," Polymer Engineering and Science, Vol. 23, pp. 771-775, 1983.
22. J. Hollin, D. Miller, and D. Vautour, "Comparison of transverse properties of 50% short and long glass fiber-reinforced nylon 6/6 resin," Journal of Reinforced Plastics and Composites, Vol. 17, pp. 1617-1624,1998.
23. R. D. Chien, S. C. Chen, P. H. Lee, and J.S. Huang, "Study on the molding characteristics and mechanical properties of injection-molded foaming polypropylene parts," Journal Reinforced Plastic & Composite, Vol. 23, pp. 429-444, 2004.
24. M. Modesti, A. Lorenzetti, D. Bon, and S. Besco, "Effect of processing conditions on morphology and mechanical properties of compatibilized polypropylene nanocomposites," Polymer, Vol. 46, pp. 10237-10245, 2005.
25. S. Apichartpattanasiri, J.N. Hay, and S.N. Kukureka, "A study of the tribological behaviour of polyamide 66 with varying injection-molding parameters," Wear, Vol. 251, pp. 1557-1566, 2001.
26. Y. K. Yang, "Optimization of injection molding process for mechanical and tribological properties of short glass fiber and polytetrafluoroethylene reinforced polycarbonate composites with grey relational analysis," A case study. Polymer Plastics Technology Engineering, Vol. 45, pp. 769-777, 2006.
27. C. P. Fung, J. R. Hwang, and C. C. Hsu, "The effect of injection molding process parameters on the tensile properties of short glass fiber-reinforced PBT," Polymer Plastics Technology Engineering, Vol. 42, pp. 45-63, 2003.
28. 鄭仲哲，潤滑纖維複合聚縮醛工程塑膠之應用與研究，大同工學院材料工程研究所，碩士論文，民國八十四年。
29. 黃繼遠，聚縮醛工程塑膠與彈性體混練改質之研究，大同工學院化學工程研究所，碩士論文，民國七十六年。
30. 詹凱元，聚縮醛機械性質之射出成型條件最佳化研究，中央大學機械工程研究所，碩士論文，民國九十六年。
31. 洪嘉維，短玻璃纖維強化聚縮醛射出成型條件最佳化與機械性質研究，中央大學機械工程研究所，碩士論文，民國九十七年。
32. 周瑞樞，聚縮醛/聚四氯乙烯複合材料界面改質之研究，大同工學院材料工程研究所，碩士論文，民國八十五年。
33. 王孝賢，聚縮醛之無電解電鍍銅研究，淡江大學機械工程系，碩士論文，民國八十七年。
34. P. Samyn, P, De Baets, G. Schouken, J.Quintelier, "Wear transition and stability of polyoxymethylene homopolymer in highly loaded applications compare to small-scale testing, " Tribology, Vol. 40, pp. 819-833, 2007.
35. C. H. Huang and C. I. Tseng, "Effect of Interface Modification between POM and PTFE on the Properties of POM/PTFE Composites," Journal of Applied Polymer Science, Vol. 44, pp. 800-807, 2000.
36. S. Hashemi, M. T. Gilbride, and J. Hodgkinson, "Mechanical Property Relationships in Glass-Filled Polyoxymethylene," Journal of Materials Science, Vol. 31, pp. 5017-5025, 1996.
37. L. H. Sun, Z. G. Yang and X. H. Li, "Study on the friction and wear behavior of POM/Al2O3 nanocomposites," Wear, Vol. 264, pp. 693-700, 2008.
38. 褚政忠，網狀電極對工具鋼放電加工特性之研究，中央大學機械工程研究所，碩士論文，民國九十年。
39. 丘建華，應用田口方法於電子薄膜配方之最佳製程條件之探討，中央大學機械工程研究所，碩士論文，民國九十年。
40. 黃華邦，黃永宏，鄭博文，由水火箭實驗了解整合六標準差手法之田口實驗設計，中華民國品質學會第40屆年會暨第10 屆全國品質管理研討會論文集，C1-10，pp. 94-105 。
41. 陳儷仁，微魚尾型模具之幾何形狀最佳化設計在微射出成型/擠壓成型的應用，雲林科技大學機械工程研究所，碩士論文，民國九十一年。
42. 劉昭宏，非等厚塑膠光學元件收縮補償之模流分析，台灣科技大學機械工程研究所，碩士論文，民國九十四年。
43. 楊春財，應用田口方法探討Tri-Tier Bond Pitch 25μm之焊線製程最佳化研究，成功大學工程科學研究所，碩士論文，民國九十三年。
44. 蔡孟諺，田口方法應用於感應馬達特性分析之研究，台灣科技大學機械工程研究所，碩士論文，民國九十四年。
45. 黃臣鴻，PC/ABS 合膠機械性質之射出成型條件最佳化，中央大學機械工程研究所，博士論文，民國九十二年。
46. 蔡文偉，PBT/GF 射出成型製程最佳化及挫屈特性研究，中央大學機械工程研究所，碩士論文，民國九十一年。
47. 李澤昌，PBT/GF 短玻璃纖維強化聚丁烯對苯二甲酸脂複合材料之磨耗性質研究，中央大學機械工程研究所，博士論文，民國九十一年。
48. 張華基，田口方法於半導體封裝製程改善之應用，銲線站之銲接強度最佳化研究，交通大學工業工程管理研究所，碩士論文，民國九十年。
49. 許峻嘉，射出成型製程參數對短玻璃纖維強化聚丁烯對苯二甲酸脂機械性質之探討研究，中央大學機械工程研究所，博士論文，民國九十三年。
50. H. Oktem, T. Erzurumlu, I. Uzman, "Application of Taguchi optimization technique in determing plastic injection molding process parameter for a thin-shall part, " Materials and Design, Vol.28, pp. 1271-1278, 2007.
51. C. S. Chen, S. C. Chen, W. L. Liaw, and R.D. Chien, "Rheological behavior of POM polymer melt flowing through micro-channels," European Polymer Journal, Vol. 44, pp. 1891-1898, 2008.
52. L. Weber, and W. Ehrfeld, "Micro-Moulding-Process, Moulds, Application," Kanstsoffe Plastic Europe, pp. 60-63, 1998.
53. P. S. Zdanski, and B. M. Vaz. "Polymer melt flow in plane channels: Hydrodynamic and thermal boundary layers," Materials Processing Technology, Vol. 179, pp. 207-211, 2006.
54. O. Babur, and T. ErzuRumlu, "Minimization of warpage and sink index in injection-molded thermoplastic parts using taguchi optimization method," Material Testing, Vol. 27, pp. 853-861, 2006.
55. Y. Wu, and A. Wu, "Taguchi methods for robust design," The Park Avenue, New York: The American Society of Mechanical Engineers; 2000.
56. Y. H. Lin, W. J. Deng, C. H. Huang, and Y. K. Yang, "Optimization of injection molding process for tensile and wear properties of polypropylene components via Taguchi and design of experiments method," Polymer Plastic Technology Engieering, Vol. 45, No. 7, pp. 769-777, 2008.
57. 楊玉如，應用主成份分析方法於多重品質製程最佳化之研究，國立交通大學工業工程研究所，碩士論文，民國八十四年。
58. 陳宏程，主成份分析法在多重品質最佳化問題上之應用-以半導體銅製程為例，國立交通大學工業工程研究所，碩士論文，民國八十七年。
59. 陳俊次，應用主成份分析法於動態系統多重品質特性最佳化之研究，國立交通大學工業工程研究所，碩士論文，民國八十八年。
60. C. T. Su, and L. I. Tong, "Multi-response robust design by principal component analysis," Total Quality Management, Vol. 8, pp. 409-416, 1997.
61. J. Antony, "Multi-response optimization in industrial experiments using Taguchi’s quality loss function and principal component analysis," Quality and Reliability Engineering International, Vol. 16, pp. 3-8, 2000.
62. 呂淮熏，側面銑削表面粗糙度預測與切穴參數最適研究，國立高雄第一科技大學工程科技研究所，博士論文，民國九十六年。
63. K. Person, "On lines and planes of closest fit to systems of points in spaces," Philosophical Magazine, Vol. 2, pp. 559-572, 1901.
64. H. Hotelling, "Analysis of a complex of statistical variables into principal components," Journal of Educational Psychology, Vol. 24, pp. 417-441, 498-520, 1933.
65. 台灣造粒股份有限公司，台灣楊梅，民國九十七年。
66. 台灣含弘股份有限公司，台灣新竹，民國九十七年。.
67. "Standard test method for tensile properties of plastics," Annual Book of ASTM Standards, D638-00, pp. 44-56.
68. "Standard test method for measuring friction and wear properties of extreme pressuer (EP) lubricating oils using SRV test machine," Annual Book of ASTM Standards, D6425-2005, pp. 1-20.
69. B. Lauke, "Theoretical considerations of toughness of short-fiber-reinforced thermoplastics," Polymer Plastic Technology Engineering, Vol. 29, pp 607-806, 1990.
70. M. C. Jeng, C. P. Fung, and T. C. Li, "The study on the tribological properties of fiber-reinforced PBT composites for various injection molding process parameters," Wear, Vol. 252, pp. 934-945, 2002.
71. K. C. Ho, and M. C. Jeng, "Tribology characteristics of short glass fiber reinforced Polycarbonate Composites," Wear, Vol. 206, pp. 60-68, 1997.
72. K. Krishan, "Composite Materials Science and Engineering," Springer, 2nd ed. pp. 379-379, 1998.