The relationship of Mold temperatures and swirl marks on the surface of microcellular plastics

Thanks to the various advantages such as lighter weight, reduced sink mark, and short cycle times, foam injection molding is being widely used for production of pallets and footwear. However, the properties of the foamed parts are somewhat decreased and result in swirl marks on the surface. So this technology is not suitable for thin and elegant products such as electronic items. Many researchers are targeting toward enhancing the strength by reducing the size of the bubbles and removing the swirl mark on the surface. In this article, we analyzed the cause of surface swirl marks as a function of mold temperature and then proposed the solution to eliminate surface trouble of foaming injection molding.