Analysis of Parameters Affecting the Product's Sink Mark from Injection Molding Process

Abstract

Problems of sink marks in the plastic injection process affects the quality of the workpiece. This study aimed to investigate the plastic injection molding process to solve the problem of product deflection for packaging products with an average thickness of 5.87 mm. The research was done to compare two groups of plastics: semi-crystalline plastics (Polypropylene) and amorphous plastics (Acrylonitrile-butadiene-styrene). This research studied the pressure in the compression range 300, 600, 900 kN and the compression range 0.5, 1.0, 1.5 and 2.0 mm. The results of analysis of the finite element process with Moldex3D showed that the semi crystalline plastics were analyzed by injection molding process and found a 0,419 mm abrasion and when analyzed by the injection molding process, the deflation marks were 0.228, 0.190, 0.164 and 0.150 mm respectively. The amorphous plastics were analyzed by the plastic injection process and found a 0,1525 mm crease, and when analyzed by the injection molding process, the cracks were 0.092, 0.059, 0.038 and 0.026 mm respectively. From the results of the experiment, it was found that the injection molding process reduced the collapse of the semi-crystalline plastics 0.499 mm and the amorphous plastics had a decrease of 0.188 mm at the compression distance of 1.5 mm., compression pressure 600 kN.