ABSTRACT
Injection molding is a polymer processing technologywhich can be used to manufacture complex parts with very high repeatability. The most significant problem in injection molding technology is the warpage of the part. The warpage is a anisotropic shrinkage of the molded element that occurs due to different conditions (temperature, pressure) in different regions of mold cavity during cooling phase of the injection molding process. Anisotropic shrinkage leads to the change of part dimensions and geometry that results with problems of achieving narrow tolerances of designed part after manufacturing. The magnitude and the manner of geometry change is very difficult to predict for complex parts without numerical methods. This effect is more significant for parts with non-uniform wall thicknesses and complicated, asymmetric shapes. The curvature is the example of asymmetric geometry that induces anisotropic shrinkage of the part. In this research. the relation between geometrical curvature of the part and its warpage was thoroughly investigated with numerical simulations performed with Autodesk Moldflow software. Along with the different curvatures several different thicknesses, part dimensions and materials were examined. In this study the optimum value of wall thickness for different curvatures was presented where warpage of the part was insignificant.
