氣體反壓對流體輔助射出成型品中空率的影響

Effect of Gas Counter Pressure on the Hollow Ratio of Fluid Assisted Injection Molding Process

10.6840/cycu201800103

高啓鴻

可視化模具 ； 氣體反壓 ； 噴泉流 ； 氣體輔助成型 ； 穿透長度 ； 掏空率 ； visual mold ； gas counter pressure ； fountain flow effect ； gas assisted injection molding ； penetration length ； hollow rate

中原大學機械工程學系學位論文

2018年

博士

鍾文仁

繁體中文

本研究使用具透明性質的PS當作充填材料來進行實驗，利用成品的透明性進行觀察，先是氣體反壓技術抑制噴泉流效應的實驗，透過可視化的模具設計來觀察反壓壓力影響熔膠流動特性，探討氣體反壓對噴泉流效應的影響。接著將氣體反壓應用於氣體輔助射出成型實驗，量測成品中氣體的穿透長度，並沿著垂直熔膠流動方向切割成品，量測掏空面積，透過實驗結果歸納出反壓對氣體輔助射出成品中空率的影響，並藉由可視化的模具設計，透過高速攝影機實際觀察不同反壓壓力對的氣體穿透的影響。 經由觀察與追蹤熔膠中粒子的流動軌跡，發現熔膠的流線在越靠近模壁，其翻轉向外的偏移距離越短，越靠近中心翻轉向外的偏移距離越長，中心線附近會在熔膠波前翻轉向外，最後停留在模壁表面形成新的凝固層。利用反壓壓力造成熔膠波前長度變化的原理，量測不同反壓壓力與不同模溫下熔膠波前長度的變化，由波前長度的變化得知反壓壓力對噴泉流效應的抑制作用，在遠澆口處較近澆口處明顯，且凝固層越厚則噴泉效應越明顯。 由氣體輔助射出成型結果顯示，當反壓壓力固定時，氣輔壓力越大，則氣體穿透長度越短，掏空面積越大，一次穿透的均勻度越佳；當氣輔壓力固定時，反壓壓力越大，則氣體穿透長度越長，掏空面積越小，一次穿透的均勻度較差；而如果固定氣輔與反壓的壓力差值，隨著氣輔與反壓壓力的提升，氣體穿透長度越長，掏空面積越小，偏向增加反壓壓力的反應；當氣輔與反壓的壓力差值越大，則氣體穿透長度越短，掏空面積越大，有較佳的均勻度，偏向增加氣輔壓力的反應，透過可視化觀察發現反壓會抑制氣輔穿透的速度。綜合以上實驗結果發現，反壓壓力可以用來有效控制成型品的穿透長度與掏空率，進而提升與穩定氣體輔助射出成型的成型品品質。

This study utilizes transparent PS as the filling material for the experiment to observe the results. The first study uses gas counter pressure technique to inhibit the fountain flow effect and employs a visualized mold design to observe the influence of counter pressure on melt flow behavior, in order to discuss the impact of the counter pressure mechanism on the fountain flow effect. The second study uses the counter pressure in gas assisted injection molding. The molded product is cut in the vertical direction with melt flow; the gas penetration length and the gas hollow area are measured. The effect of counter pressure on the hollow rate of the gas assisted molded product is concluded from the experimental results. With the visualized mold design, a high-speed camera observes the inhibitory effect of different bar of counter pressures. In the first study the flow trajectory of particles in the melt is observed and tracked, and the findings showing that the closer the flow line of the melt is to the mold wall, the shorter the offset distance will be for the outward flip. Moreover, the closer to the center it is, the longer the offset distance of the outward flip; meaning it flips outward in the melt-front nearby the center line and stays on the mold wall surface to form a new frozen layer. The melt-front length changes under different counter pressures and different mold temperatures. The front length changes present the inhibitory effect of counter pressure on the fountain flow effect, which is more apparent at the far gate than at the near gate, and the thicker the frozen layer is, the more apparent the fountain effect is. The results show that when the counter pressure is fixed, the higher the gas assisted pressure is, the shorter is the gas penetration length, the larger is the gas hollow area, and the better is the primary penetration uniformity. When the gas assisted pressure is fixed, the higher the counter pressure is, the longer is the gas penetration length, the smaller is the gas hollow area, and the relatively poor is the primary penetration uniformity. If the difference between the gas assisted pressure and counter pressure is fixed, then as the gas assisted and counter pressures increase, the gas penetration length increases and the hollow area decreases. The larger the difference is between the gas assisted pressure and counter pressure, the shorter is the gas penetration length, the larger is the hollow area, and the better is the primary penetration uniformity. The effect of counter pressure and gas assisted pressure on the penetration length and hollow area of gas assisted molding is observed in the visual mold. The result shows that the counter pressure can inhibit the gas penetration rate. To sum up the above experimental results, the counter pressure can be effectively used to control the gas penetration length and hollow rate of the molded product, so that the molded product quality of gas assisted molding can be upgrade and be more stable.

1. 1. Rose, W., 1961, "Fluid-Fluid Interfaces in Steady Motion," Nature, 191, pp. 242-243.
   連結：
2. 2. Yokoi, H., 2002, "Visualization Analysis of Front Behavior during Filling Process of Injection Mold Cavity by Two-Axis Tracking System," Journal of Materials Processing Technology, 130-131, pp. 328-333.
   連結：
3. 3. Yang, W. M. and Yokoi, H., 2003, " Visual Analysis of the Flow Behavior of Core Material in a Fork Portion of Plastic Sandwich Injection Molding," Polymer Testing, 22(1), pp. 37-43.
   連結：
4. 4. Kanetoh, Y. and Yokoi, H., 2012, "Visualization Analysis of Resin Flow Behavior around a Flow Front Using a Rotary Runner Exchange System," International Polymer Processing, 27(3), pp. 310-317.
   連結：
5. 7. Guergov, M. G., et al., 1998, United States Patent 5716561.
   連結：
6. 8. Chen, S. C., Liao, W. H. and Chien, R. D., 2012, "Structure and Mechanical Properties of Polystyrene Foams Made through Microcellular Injection Molding via Control Mechanisms of Gas Counter Pressure and Mold Temperature," International Communications in Heat and Mass Transfer, 39(8), pp. 1125-1131.
   連結：
7. 9. Chen, S. C., Hsu, P. S. and Hwang, S. S., 2013, "The Effects of Gas Counter Pressure and Mold Temperature Variation on the Surface Quality and Morphology of the Microcellular Polystyrene Foams," Journal of Applied Polymer Science, 127(6), pp. 4769-4776.
   連結：
8. 10. Chen, S. C., Chien, M. Y., Lin, S. H., Chien, R. D. and Lin, M. C., 2015, "Effect of Gas Counter Pressure on the Carbon Fiber Orientation and the Associated Electrical Conductivities in Injection Molded Polymer Composites," Journal of Polymer Engineering, 35(5), pp. 503-510.
   連結：
9. 11. Chen, S. C., Hsu, K. S. and Huang, J. S., 1995, "Experimental Study on Gas Penetration Characteristics in a Spiral Tube during Gas-Assisted Injection Molding," Industrial & Engineering Chemistry Research, 34(1), pp. 416-420.
   連結：
10. 12. Chen, S. C., Chien, R. D., Chen, Y. C. and Teng, M. Y., 2004, "Study of Mouldability in Gas-Assisted Injection Moulded Fibre-Reinforced Nylon Parts,” Plastics Rubber and Composites, 33(2-3), pp. 113-119.
    連結：
11. 13. Chien, R. D., and Chen, S. C., 2004, "Investigations into Surface Visual Quality of Gas-Assisted Injection Moulded Polypropylene Parts," Plastics Rubber and Composites, 33(4), pp. 155-162.
    連結：
12. 14. 日本專利，"Gas Pressurizing Injection Molding Method"，特開2004-223879
    連結：
13. 15. 林鈺婉，2008，"臨界微細發泡射出成型反壓機制建立並應用於流變特性研究"，博士論文，中原大學機械工程學研究所。
    連結：
14. 16. Okamoto, K. T., 2003, Microcellular Processing, Hanser Gardner Publishers, München, Wien.
    連結：
15. 17. Chen, S. C., Hsu, P. S. and Lin, Y. W., 2011, "Establishment of Gas Counter Pressure Technology and Its Application to Improve the Surface Quality of Microcellular Injection Molded Parts," International Polymer Processing, 26(3), pp. 275-282.
    連結：
16. 18. Bay, R. S. and Tucker, C. L., 1992, "Fiber Orientation in Simple Injection Moldings. Part I: Theory and Numerical Methods," Polymer Composites, 13(4), pp. 317-331.
    連結：
17. 19. Chien, R. D., Chen, C. S. and Chen, S. C., 2003, "Effect of Gas Channel Design on the Molding Window of Gas-Assisted Injection Molded PS Parts," Journal of Applied Polymer Science, 90(11), pp. 2979-2986.
    連結：
18. 20. Chien, R. D. and Chen, S. C., 2002, "Investigations on the Molding Window of Gas-Assisted Injection Molded Polystyrene Plates with Various Gas Channel Design," Plastics Rubber and Composites: Processing and Applications. 31(8), pp. 336-343.
    連結：
19. 21. Chien, R. D. and Chen, S. C., 2004, "Study of the Bending Properties in Gas-Assisted Injection Molded Fiber-Reinforced Nylon Parts", Journal of Reinforced Plastics and Composites, 23(16), 1779 -1794.
    連結：
20. 22. Chen, S. C., Hu, S.Y., Chao, S. M. and Chien, R.D., 2000. "Simulation of Mold-Cooling Process for Gas-Assisted Injection Molded Parts Designed with A Top Rib on Gas Channel," Polymer Engineering Science, 40(3), pp. 595-606.
    連結：
21. 23. Chien, R. D. Chen, S. C., Lin, M.C. and Chen, C. S., 2004, "Surface Visual Quality of Gas-Assisted Injection Molded ABS Parts with Various Gas Channel Design," Journal of Reinforced Plastics and Composites, 23(10), pp 1115-1129.
    連結：
22. 24. Lin, K. Y. and Liu, S. J., 2010, "Morphology of Fluid Assisted Injection Molded Polycarbonate/Polyethylene Blends," Macromolecular Materials and Engineering, 295, pp. 342-350.
    連結：
23. 1. Rose, W., 1961, "Fluid-Fluid Interfaces in Steady Motion," Nature, 191, pp. 242-243.
    連結：
24. 2. Yokoi, H., 2002, "Visualization Analysis of Front Behavior during Filling Process of Injection Mold Cavity by Two-Axis Tracking System," Journal of Materials Processing Technology, 130-131, pp. 328-333.
    連結：
25. 3. Yang, W. M. and Yokoi, H., 2003, " Visual Analysis of the Flow Behavior of Core Material in a Fork Portion of Plastic Sandwich Injection Molding," Polymer Testing, 22(1), pp. 37-43.
    連結：
26. 4. Kanetoh, Y. and Yokoi, H., 2012, "Visualization Analysis of Resin Flow Behavior around a Flow Front Using a Rotary Runner Exchange System," International Polymer Processing, 27(3), pp. 310-317.
    連結：
27. 7. Guergov, M. G., et al., 1998, United States Patent 5716561.
    連結：
28. 8. Chen, S. C., Liao, W. H. and Chien, R. D., 2012, "Structure and Mechanical Properties of Polystyrene Foams Made through Microcellular Injection Molding via Control Mechanisms of Gas Counter Pressure and Mold Temperature," International Communications in Heat and Mass Transfer, 39(8), pp. 1125-1131.
    連結：
29. 9. Chen, S. C., Hsu, P. S. and Hwang, S. S., 2013, "The Effects of Gas Counter Pressure and Mold Temperature Variation on the Surface Quality and Morphology of the Microcellular Polystyrene Foams," Journal of Applied Polymer Science, 127(6), pp. 4769-4776.
    連結：
30. 10. Chen, S. C., Chien, M. Y., Lin, S. H., Chien, R. D. and Lin, M. C., 2015, "Effect of Gas Counter Pressure on the Carbon Fiber Orientation and the Associated Electrical Conductivities in Injection Molded Polymer Composites," Journal of Polymer Engineering, 35(5), pp. 503-510.
    連結：
31. 11. Chen, S. C., Hsu, K. S. and Huang, J. S., 1995, "Experimental Study on Gas Penetration Characteristics in a Spiral Tube during Gas-Assisted Injection Molding," Industrial & Engineering Chemistry Research, 34(1), pp. 416-420.
    連結：
32. 12. Chen, S. C., Chien, R. D., Chen, Y. C. and Teng, M. Y., 2004, "Study of Mouldability in Gas-Assisted Injection Moulded Fibre-Reinforced Nylon Parts,” Plastics Rubber and Composites, 33(2-3), pp. 113-119.
    連結：
33. 13. Chien, R. D., and Chen, S. C., 2004, "Investigations into Surface Visual Quality of Gas-Assisted Injection Moulded Polypropylene Parts," Plastics Rubber and Composites, 33(4), pp. 155-162.
    連結：
34. 14. 日本專利，"Gas Pressurizing Injection Molding Method"，特開2004-223879
    連結：
35. 15. 林鈺婉，2008，"臨界微細發泡射出成型反壓機制建立並應用於流變特性研究"，博士論文，中原大學機械工程學研究所。
    連結：
36. 16. Okamoto, K. T., 2003, Microcellular Processing, Hanser Gardner Publishers, München, Wien.
    連結：
37. 17. Chen, S. C., Hsu, P. S. and Lin, Y. W., 2011, "Establishment of Gas Counter Pressure Technology and Its Application to Improve the Surface Quality of Microcellular Injection Molded Parts," International Polymer Processing, 26(3), pp. 275-282.
    連結：
38. 18. Bay, R. S. and Tucker, C. L., 1992, "Fiber Orientation in Simple Injection Moldings. Part I: Theory and Numerical Methods," Polymer Composites, 13(4), pp. 317-331.
    連結：
39. 19. Chien, R. D., Chen, C. S. and Chen, S. C., 2003, "Effect of Gas Channel Design on the Molding Window of Gas-Assisted Injection Molded PS Parts," Journal of Applied Polymer Science, 90(11), pp. 2979-2986.
    連結：
40. 20. Chien, R. D. and Chen, S. C., 2002, "Investigations on the Molding Window of Gas-Assisted Injection Molded Polystyrene Plates with Various Gas Channel Design," Plastics Rubber and Composites: Processing and Applications. 31(8), pp. 336-343.
    連結：
41. 21. Chien, R. D. and Chen, S. C., 2004, "Study of the Bending Properties in Gas-Assisted Injection Molded Fiber-Reinforced Nylon Parts", Journal of Reinforced Plastics and Composites, 23(16), 1779 -1794.
    連結：
42. 22. Chen, S. C., Hu, S.Y., Chao, S. M. and Chien, R.D., 2000. "Simulation of Mold-Cooling Process for Gas-Assisted Injection Molded Parts Designed with A Top Rib on Gas Channel," Polymer Engineering Science, 40(3), pp. 595-606.
    連結：
43. 23. Chien, R. D. Chen, S. C., Lin, M.C. and Chen, C. S., 2004, "Surface Visual Quality of Gas-Assisted Injection Molded ABS Parts with Various Gas Channel Design," Journal of Reinforced Plastics and Composites, 23(10), pp 1115-1129.
    連結：
44. 24. Lin, K. Y. and Liu, S. J., 2010, "Morphology of Fluid Assisted Injection Molded Polycarbonate/Polyethylene Blends," Macromolecular Materials and Engineering, 295, pp. 342-350.
    連結：
45. 5. Balevski, A. T., et al., 1978, United States Patent 4092385.
46. 6. Guergov,, M. G., et al., 1995, United States Patent 5441680.
47. 25. 張榮語，1995，射出成型模具設計-模具設計，高立圖書有限公司，台灣。
48. 26. 楊衛民，2008，注塑成型新技術，化學工業出版社，台灣。
49. 5. Balevski, A. T., et al., 1978, United States Patent 4092385.
50. 6. Guergov,, M. G., et al., 1995, United States Patent 5441680.
51. 25. 張榮語，1995，射出成型模具設計-模具設計，高立圖書有限公司，台灣。
52. 26. 楊衛民，2008，注塑成型新技術，化學工業出版社，台灣。