Influence of rapid mold temperature variation on surface topography replication and appearance of injection-molded parts

In this work an innovative technology for rapid heating and cooling of injection molds has been developed and used to analyze the effect of fast variations of the mold temperature on the improvement of micro features replication and moldings appearance. The obtained numerical and experimental results show that, by rapidly heating the mold cavity, the polymer melt can accurately replicate the mold surface topography. Furthermore, the mold cavity heating combined with the fast cooling of the molded part significantly contributes to contrast the development of surface defects, such as weld lines, which are due to stress relaxation. (C) 2012 CIRP.