Hướng phát triển - : KẾT LUẬN VÀ HƯỚNG PHÁT TRIỂN- 123docz.net

CHƯƠNG 6 : KẾT LUẬN VÀ HƯỚNG PHÁT TRIỂN

6.2. Hướng phát triển

Với các kết quả đạt được, những hướng phát triển sau được đề xuất:

- Nghiên cứu cải tiến hệ thống gia và giải nhiệt để có thể giải nhiệt cho lịng khn với những mức nhiệt độ cao hơn để giảm thời gian chu kỳ ép phun.

- Thiết kế bộ khn tích hợp hệ thống gia nhiệt bằng khí nóng cho sản phẩm ứng dụng thực tế bằng vật liệu composite.

- Thay đổi cơ cấu đỡ tấm insert từ xylanh sang cơ cấu khác hiệu quả hơn.

- Nghiên cứu tối ưu năng lượng với hệ thống gia nhiệt bằng khí nóng tích hợp trong lịng khn ép phun.

DANH MỤC TÀI LIỆU THAM KHẢO

[1]. Phạm Sơn Minh và Trần Minh Thế Uyên, “Giáo trình thiết kế và chế tạo khn phun ép nhựa”, nhà xuất bản đại học quốc gia TPHCM. 2014.

[2]. Vũ Hồi Ân, “Thiết kế khn cho sản phẩm nhựa”, Nhà xuất bản Viện máy và dụng cụ - Trung tâm đào tạo và thực hành CAD/CAM, 1994.

[3]. Nguyễn Hộ, “Nghiên cứu ảnh hưởng của phương pháp gia nhiệt bằng khí nóng đến khả năng điền đầy lịng khn sản phẩm nhựa dạng thành mỏng”, Đại học Sư phạm Kỹ thuật Tp.HCM, 2015.

[4]. Shia-Chung Chen, Jen-An Chang, Ying-Chieh Wang and Chun-Feng Yeh, “Development of gas-assisted dynamic mold temperature control system and its application for micro molding”, 2209-2012 / ANTEC 2008.

[5]. Shia-Chung Chen, Rean-Der Chien, Su-Hsia Lin, Ming-Chung Lin and Jen-An Chang, “Feasibility evaluation of gas-assisted heating for mold surface temperature control during injection molding process”, International Communications in Heat and Mass Transfer, Vol. 36, 2009, pp. 806–812. [6]. Shia-Chung Chen , Pham Son Minh and Jen-An Chang, “Gas-assisted mold

temperature control for improving the quality of injection molded parts with fiber additives”, International Communications in Heat and Mass Transfer, Vol. 38, 2011, pp. 304–312.

[7]. G. Wang, G. Zhao, H L. Y. Guan, “Research of thermal response simulation and mold structure optimization for rapid heat cycle molding processes, respectively, with steam heating and electric heating”, Journal of Materials & Design, Vol. 31, Issue 1, 2010, pp. 382-395.

[8]. S. Wong, J. W. S. Lee, H. E. Naguib and C. B. Park, “Effect of processing parameters on the mechanical properties of injection molded thermoplastic

polyolefin (TPO) cellular foams”, Macromolecular Materials and Engineering, Vol. 293, Issue 7, 2008, pp. 605-613.

[9]. A. Kumar, P. S. Ghoshdastidar and M. K Muju, “Computer simulation of transport processes during injection mold-filling and optimization of the molding conditions”, Journal of Materials Processing Technology, Vol. 120, Issues 1–3, 2002, pp. 438-449.

[10]. A. C. Liou, R. H. Chen, C. K. Huang, C. H. Su and P. Y. Tsai, “Development of a heat-generable mold insert and its application to the injection molding of microstructures”, Microelectronic Engineering, Vol. 117, 2014, pp. 41-47. [11]. S. Liparoti, R. Pantani, A. Sorrentino, V. Speranza and G. Titomanlio,

“Hydrophobicity tuning by the fast evolution of mold temperature during injection molding”, Journal of Polymers, Vol. 10, Issue 3, 2018, pp. 1-15. [12]. S. C. Chang and S. J. Hwang, “Simulation of infrared rapid surface heating for

injection molding”, International Journal of Heat and Mass Transfer, Vol. 49, Issues 21-22, 2006, pp. 3846-3854.

[13]. M. C. Yu, W. B. Young and P. M. Hsu, “Micro injection molding with the infrared assisted heating system”, Materials Science and Engineering A, Vols. 460-461, 2007, pp. 288-295.

[14]. H. L. Chen, S. C. Chen, W. H. Liao, R. D. Chien and Y. T. Lin, “Effects of insert film on asymmetric mold temperature and associated part warpage during in-mold decoration injection molding of PP parts”, International Communications in Heat and Mass Transfer, Vol. 41, 2013, pp. 34-40.

[15]. S. Y. Yang, S. C. Nian, S. T. Huang and Y. J. Weng, “A study on the micro- injection molding of multi-cavity ultra-thin parts”, Polymers Advances Technologies, 2011.

[16]. Shia-Chung Chen, Yu-Wan Lin, Rean-Der Chien, Hai-Mei Li, “Variable mold temperature to improve surface quality of microcellular injection molded parts

using induction heating technology”, Advances in Polymer Technology, Vol. 27, No. 4, 2008, pp. 224–232.

[17]. B. Sha, S. Dimov, C. Griffiths and M.S. Packianather, “Investigation of micro- injection moulding: factors affecting the replication quality”, Journal of Materials Processing Technology, 2007, pp. 284–296.

[18]. Shia-Chung Chen, Wen-Ren Jong, Jen-An Chang and Hsin-Shu Peng, “Simulation and verification on rapid mold surface eating/cooling using electromagnetic induction technology”, 4th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics Cairo, Egypt, 2005.

[19]. M. C. Jeng, S. C. Chen, P. S. Minh, J. A. Chang and C. S. Chung, “Rapid mold temperature control in injection molding by using steam heating”, International Communications in Heat and Mass Transfer, Vol. 37, Issue 9, 2010, pp. 1295- 1304.

[20]. Pham Son Minh, Thanh Trung Do and Tran Minh The Uyen, “The feasibility of external gas-assisted mold-temperature control for thin-wall injection molding”, Advances in Mechanical Engineering, Vol. 10(10), 2018, pp. 1–13, DOI: 10.1177/1687814018806102.

[21]. Đỗ Thành Trung và Phạm Sơn Minh, “Nghiên cứu thiết kế và chế tạo tay máy gia nhiệt cho khuôn ép nhựa trong qui trình chế tạo thiết bị y sinh - Lab on Chip – LOC”, Đề tài cấp Sở Khoa học và Công nghệ Tp.HCM, 45/2015/HĐ- SKHCN.

[22]. C.Wilcox, Turbulence Modeling for CFD, 2nd editor, DCW Industries, 1998. [23]. Theodore L. Bergman Adrienne S. Lavine, Frank P. Incropera and David P.

DeWitt, “Fundamentals of heat and mass transfer”, Wiley, 7 edition, April 12, 2011.

[24]. S. Meister and D. Drummer, “Affecting the ageing behaviour of injection- moulded microparts using variothermal mould tempering”, Advances in Mechanical Engineering, 2013, pp. 1-7.

[25]. Y. T. Sung, S. J Hwang, H. H. Lee and D. Y. Huang, “Study on induction heating coil for uniform mold cavity surface heating”, Adv. Mech. Eng., Vol. 6, 2014, DOI:10.1155/2014/349078.

[26]. D. Yao, T. E. Kimerling and B. Kim, “High-frequency proximity heating for injection molding applications”, Polym. Eng. Sci., Vol. 6, 2006, pp. 938–945, DOI:10.1002/pen.20548.

[27]. B. H. Kim and D. Yao, “Method for rapid mold heating and cooling”, US Patent 684645, 2005-01-25.

[28]. Jingyi Xu, “Microcellular injection molding”, John Wiley & Sons, Inc, 2010. [29]. Trần Minh Thế Uyên, Luận án Tiến sỹ “Nghiên cứu ảnh hưởng của gia nhiệt

khn phun ép bằng khí nóng đến độ bền sản phẩm nhựa dạng thành mỏng”, Đại học Sư phạm Kỹ thuật Tp.HCM, 2020.

[30]. Schiller and F. Gary, “Injection unit: Screw”, Carl Hanser Verlag GmbH, 2018, eISBN: 978-1-56990-687-3.

PHỤ LỤC

International Journal of Advanced Research in Science, Engineering and Technology

Study on the Temperature Distribution for Mold Heating Process

Cao Van Thinh, Thanh Trung Do

Ho Chi Minh City University of Technology and Education, Hochiminh city, Vietnam

ABSTRACT: In the plastic injection molding process, the product is formed in a very short time, the selection of the optimal parameters (temperature) to make the filling process of liquid plastic takes place easily, quickly, and reducing. defects of plastic products, especially for products of small thickness (thin walls) and large lengths. With this study, the authors will simulate the process of heating the cavity with hot air integrated inside the mold, then bring water into the mold cooling system, change the mold temperature, to learn and evaluate heating process and cavity cooling process with the thickness of the insert. After the experiment, find the most suitable insert temperature. Through the research process, it was found that the heating process at 20s with a heating temperature of 400 ° C, the highest value of about 153⁰C with the insert plate thickness is 0.5mm.

KEY WORDS: Injection molding, injection pressure, melt flow length, mold temperature, melt temperature. I.INTRODUCTION

In the field of processing and manufacturing of plastic products, plastic injection method is one of the most used method, especially for products with large length and small thickness, so if there is no experience in choosing the mold temperature, as well as the investment in mold temperature control devices, product defects will easily appear during injection molding, On the contrary, if the mold temperature is reasonable, the process of balancing the flow of plastic into the mold cavity will be done more easily. This is an important basis for achieving uniform quality for a large series of products in the plastic injection production process, especially for molds with many different sizes of molds. This study will focus on simulating the heating process for the mold cavity, to find out the difference in temperature before and after heating, as a basis for calculating the appropriate mold temperature for each plastic, and plastic flow length.

II. SIMULATION METHODS

ANSYS CFX is the most popular and commonly used fluid dynamics analysis module that can help to reliably and accurately simulate different types of fluid flows.

Content Description Parameter

1. Geometry - Inlet - Outlet1 - Outlet2 - Outlet3 2. Mesh - Inflation + Geometry: 2 Bodies + Boundary: 1 face + Maximun Thickness: 1mm

International Journal of Advanced Research in Science, Engineering and Technology

3. Setup - Air (U, V, W=0, P=0, T=30°C)

+ inlet ( Normal Speed: 100m/s, Static temperature: 400°C)

+ Outlet (Opening temperature: 30°C) - Stamp (Material: stell, temperature: 30°C) - Output (Time interval: 0.1s)

4. Solution - Start run

5. Results - Stamp side:

+ Model: Variable + Variabel: Temperature + Range: Use Spectified - Default Legend View 1 + Title mode: Variable + Precision: 1 - Fixed

Figure 1: ANSYS simulation process. III. RESULTS AND DISCUSSION

Research on the temperature distribution of the mold cavity after heating with hot air from internal the mold with gas inlet air temperature of 400°C, heating time 20s, and steel cavity surface by simulation

International Journal of Advanced Research in Science, Engineering and Technology

5 s 10 s 15 s 20 s 200 250 300 350 400

Figure 3: Mold temperature distribution after heating time by simulation mold cavity with heating surface with thickness of stamp insert is 0.5mm

+ Highest temperature at spraying position in case of spraying temperature of 4000C and spraying time of 20s is 153.50C, further away from lower temperature.

t C T

International Journal of Advanced Research in Science, Engineering and Technology

5 s 10 s 15 s 20 s 200 250 300 350 400

Figure 4: Mold temperature distribution after heating time by simulation mold cavity with heating surface with thickness of stamp insert is 0.3mm

+ Highest temperature at spraying position in case of spraying temperature of 4000C and spraying time of 20s is 1470C, further away from lower temperature.

t0C T

International Journal of Advanced Research in Science, Engineering and Technology

5 s 10 s 15 s 20 s 200 250 300 350 400

Figure 5: Mold temperature distribution after heating time by simulation mold cavity with heating surface with thickness of stamp insert is 0.1mm

+ Highest temperature at spraying position in case of spraying temperature of 4000C and spraying time of 20s is 146,20C, further away from lower temperature.

t C T

International Journal of Advanced Research in Science, Engineering and Technology

Figure 6: The chart shows the insert plate temperature with thickness of stamp insert is 0.5mm

Figure 7: The chart shows the insert plate temperature with thickness of stamp insert is 0.3mm

T E M P E R A T U R E I N SE R T ( OC)

TEMPERATURE OF HOT AIR (OC)

HEATING TIME T E M P E R A T U R E I N S E R T S T A M P ( OC) TEMPERATURE OF (OC) HEATING TIME

International Journal of Advanced Research in Science, Engineering and Technology

Figure 8: The chart shows the insert plate temperature with thickness of stamp insert is 0.1mm IV. CONCLUSION

- From the above results we see, the greater the hot air temperature and the longer the heating time, the greater the insert plate temperature; during heating at a time of 20 seconds with a heating temperature of 400°C, the highest value is about 153⁰C.

- In 3 insert stamp with product thickness of 0.1mm, 0.3mm, 0.5mm, the 0.5mm insert stamp has the highest heating value.

Acknowledgement: This work belongs to the project grant No: B2019_SPK_03. funded by Ministry of Education and Training, and hosted by Ho Chi Minh City University of Technology and Education, Vietnam

REFERENCES

[1]. B. Sha, S. Dimov, C. Griffiths, M.S. Packianather.., “Investigation of micro-injection moulding: Factors affecting the replication quality”,

Journal of Materials Processing Technology, 2007, 284–296.

[2]. Jingyi Xu, “Microcellular Injection Molding”, Published by John Wiley & Sons, Inc, 2010.

[3]. K. F. Zhang, Zhen Lu..., “Analysis of morphology and performance of PP microstructures manufactured by micro injection molding”,

Microsyst Technol, 2008.

[4]. Peter Jones, “The Mould Design Guide”, Published by Smither Rapra, 2008.

[5]. S.-Y. Yang, S.-C. Nian, S.-T. Huang and Y.-J. Weng, “A study on the micro-injection molding of multi-cavity ultra-thin parts”, Polymers Advances Technologies, 2011.

[6]. Shia-Chung Chen, Jen-An Chang, Ying-Chieh Wang, Chun-Feng Yeh, “Development of Gas-Assisted Dynamic Mold Temperature Control

System and Its Application for Micro Molding”, ANTEC, 2008, Page 2208-2212.

[7]. Shia-Chung Chen, Rean-Der Chien, Su-Hsia Lin, Ming-Chung Lin, Jen-An Chang Shia-Chung Chen, Rean-Der Chien, Su-Hsia Lin, Ming-

Chung Lin, “Feasibility evaluation of gas-assisted heating for mold surface temperature control during injection molding process”, International

Communications in Heat and Mass Transfer, vol 36, 2009, Page 806-812.

[8]. Shia-Chung Chen, Wen-Ren Jong, Jen-An Chang and Hsin-Shu Peng.., “Simulation and verification on rapid mold surface heating/cooling

using electromagnetic induction technology”, 4th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics Cairo,

Egypt, 2005. T E M P E R A T U R E I N S E R T S T A M P ( OC) TEMPERATURE OF (OC) HEATING TIME