Control factors of foam structure and properties in microcellular injection molding
Toshitaka KANAI, Toshitaka KANAI, Hiroshi KAWATO, Hirofumi GODA
Idemitsu Petrochemical Co., Ltd.
Japan

Keywords: Microcellular injection moldin, polycarbonate, foam structure

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We investigated the foaming control factors in microcellular injection molding method, in terms of a material design and a forming condition, and this report describes the physical properties of the samples prepared on various processing condition�D
By optimization of a material design, a processing condition and a molding design , microcellular injection molding technology has potentialities of forming a homogeneous and microcell-structure ,which is expected several excellent physical properties. For example, co-polymer PC and long chain branching PC give better cell size uniformity and smaller cell size compared with general PC�DFurther, the addition of foam nucleus, injection speed and using core back process are control factors�DIf we choose the optimum condition carefully, the foam size can be controlled about 10ƒÊm and the distribution of cell size is uniform. Mucellullar has good merits such as dimensional stability and reducing warpage and shrinkage, especially for glass fiber filled materials and random dispersion of glass fibers is observed by using this technology.