Experimental study of water assisted injection molding

Créé le : 15/09/2010 - Mis à jour le : 15/11/2012

The objective of this work is to establish relations between water assisted molding parameters and product property. The molded part is a polypropylene handle, with a nearly circular outer cross section. Three different molding techniques were selected: overflow, short shot and co-injection. Regular wall thicknesses were obtained with the overflow process, whereas for the two other processes, the wall thickness varied from 3 to 4 mm. No significant wall thickness variations were observed when varying the molding parameters, except for the overflow process when varying the polymer filling flow rate and the polymer packing time. The water injection pressure level has been linked to the pressure drop in the polymer, but also to the size of the water entrance near the injector. The cristallinity ratio appeared to be quite homogeneous.