Improving the Properties of Injection Molded Products with Induction Heating and Cooling Molds
Yasuhiko Murata, Masayoshi Koike, and Song Pan
Department of Mechanical Engineering, Nippon Institute of Technology, 4-1 Gakuen-dai, Miyashiro-machi, Minamisaitama-gun, Saitama 345-8501, Japan
An induction heating and cooling mold that can keep the surface temperature of the entire mold cavity uniform and has a new heating and cooling insert with a gas vent mechanism is designed and produced. The effects of the temperature of the mold cavity surface, of the cavity air during the melt filling process, and of the organic gas generated fromthe melt on the appearance andmechanical properties of an injectionmolded product made of high impact polystyrene are studied. It is found that the heating and coolingmold with a gas vent can suppress molding defects, such as a weld lines and gas burns, and can greatly increase the displacement ratio of molded products obtained in the tensile test. This means that the effects of the gas vent and the surface temperature of the cavity have been quantitatively clarified using this type of mold.
-  Y. Hara, “Full 3D-Digital Surface Texturing,D3Texture and 3D – Digital Movement,” Proc. of 2014 Conf. on Die and Mold Technology, pp. 49-52, 2014.
-  N. Tada, Y. Inoue, et al., “Introduction of the Multi color Molding which Realizes 3D Decoration,” Preprints of Seikei-Kakou Autumnal Meeting 2012, pp. 117-118, 2012.
-  The Japan Society for Technology of Plasticity, Flow Simulation – Plastics Molding, Corona Publishing Co. Ltd., p. 57, 2004.
-  H. Yokoi, Y. Murata, et al., “Visual Analysis of Weld Line Vanishing Process by Glass- Inserted Mold,” Proc. of the 49th Annual Technical Conference ANTEC’91, pp. 367-371, 1991.
-  A. Ebisawa, “Heat and Cool System to Get the Excellent Surface Finishing,” J. of the Japan Society of Polymer Processing, Vol.11, No.5, pp. 397-400, 1999.
-  A. Wada, et al., U.K.Patent GB2081 171A, 1982.
-  R. Nicolas and F. Jose, “How Inductive Heating Can Improve Plastic Injection,” J. of the Japan Society of Polymer Processing, Vol.23, No.12, pp. 705-710, 2011.
-  R. Yoshino, “Cavity Surface Quick High Temperaturize Technology with Slender Tube Heater,” J. of the Japan Society of Polymer Processing, Vol.20, No.3, p. 192, 2008.
-  NADAInnovation, E-Mold,
http://www.witswell.co.jp/HTM/emold/emold.html [accessed on August 23, 2011]
-  T. Iwasawa, Y. Fukushima, et al., “A Basic Study on Spot Heating Weld-less Manufacturing System – Die Temperature Distribution by CAE Analysis for a Design –,” Preprints of Seikei-Kakou Annual Meeting 2011, pp. 91-92, 2011.
-  T. Yasuhara, K. Kato, et al., “Improvement of Transcription Property of Fine Surface Structure by Rapid Heating Mold,” Extended Abstracts of the Polymer Processing Society 14th Annual Meeting, pp. 41-42, 1998.
-  Y. Murata, K. Kino, et al., “Improvement on Injection Molded Products Appearance by Induction Heating Mold,” J of the Japan Society for Precision Engineering, Vol.75, No.3, pp. 407-411, 2009.
-  Y. Murata, K. Kino, et al., “Improvement on Injection Molded Products Appearance by Induction Heating Mold,” Abstracts for 24nd Annual Meeting of Polymer Processing Society, CD-ROM, File No.S13-1327, 2008.
-  A. Sato, M. Kunieda, et al., “Manufacturing of High Cycle and High Precision Injection Molds by Diffusion Bonding of Laminated Thin Metal Sheets,” J of the Japan Society for Precision Engineering, Vol.70, No.12, pp. 1533-1537, 2004.
-  H. Yokoi and S. Takematsu, “Analyses of Correlation between Weld-Line Generation and Gas-Vent Behavior I,” The Japan Society of Polymer Processing 2001 Technical Papers, pp. 263-264, 2001.
-  Y. Murata, “Technology of Mold Temperature Control in Injection Molding,” J. of the Japan Society of Polymer Processing, Vol.23, No.12, p. 700, 2011.