Influence of the site of the runner on the waarpage fo an injection moulded article made from glass fibre filled material

摘要

A typical problem in the injection moulding of thermoplastics filled with short glass fibre is the warpage of articles. The orientation of the glass fibre in the composite is the most important factor affecting the shrinkage, warpage, and mechanical charactreristics of the injection moulded article [1]. The orientation of the glass fibre is determined in many ways by the choice of the site of the runner. Methods of finite element analysis make it possible to model the orientation of the fibre filler in the polymer matrix, and also the shrinkage and deformation behaviour of the moulding [2-5]. The accuracy of such modelling is quite acceptable, in spite of the considerable simplification of the processes occurring in the mould cavity (in particular, the absence of damage to the fibre particles during processing is assumed, the presence of an interphase layer is ignored, no account is taken of the influence of the supermolecular structure, and so on).