Influence of rapid mould temperature variation on the appearance of injection-moulded parts

Abstract

In this work, an innovative technology for the rapid heating and cooling of injection moulds has been developed and used to analyse the effect rapid variations of the mould temperature on the improvement of mouldings' appearance in terms of gloss. The obtained experimental results show that by maintaining an elevated mould surface temperature, the polymer melt is prevented from solidifying prematurely in the filling and packing stage, thereby improving the replication of the mirror-finished cavity surface. Furthermore, the mould cavity heating combined with the rapid cooling of the moulded part significantly contributes to contrasting the development of surface defects, such as weld line marks. © 2013 Journal of Mechanical Engineering.