Development of Heating and Cooling Injection Mold with Far-Infrared Radiation Heater
Yasuhiko Murata and Masahiro Kuramochi
Department of Mechanical Engineering, Nippon Institute of Technology
4-1 Gakuendai, Miyashiro-mach, Minamisaitama-gun, Saitama 345-8501, Japan
Several rapid heating and cooling molding methods have been developed for practical use to improve the surface quality of plastic injection-molded products. These methods, however, need expensive equipment and complex molds that require vast know-how, and hence cannot be applied easily to actual production. In order to establish a molding method in which the mold’s cavity surfaces can easily be heated, we designed and manufactured a heating and cooling injection mold with a far-infrared radiation heater. Using this mold, we molded a high-impact polystyrene molded product, and found that the use of such a mold could lead to a decrease in the V-shaped groove depth of weld lines, as well as to an improvement in the transcription of the mold’s cavity surface quality onto the molded product. We also carried out tensile tests on the molded products to confirm whether the use of such a mold could increase the product’s elongation at break.
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