PT  - JOURNAL ARTICLE
AU  - Gondár, Ernest
AU  - Schrek, Alexander
AU  - Švec, Pavol
TI  - Reduction of Sink Marks in Injection Overmolding Process of Metal-Plastic Parts
DP  - 2016 Dec 1
TA  - Manufacturing Technology Journal
PG  - 1259--1264
VI  - 16
IP  - 6
AID - 10.21062/ujep/x.2016/a/1213-2489/MT/16/6/1259
IS  - 12132489
AB  - Metal-plastic parts with steel inserts prepared by overmolding technique showed several molding defects including sink marks. The depths of sink marks on overmolding metal-plastic parts prepared at two injection overmolding temperatures of 280 and 230 °C and the same packing pressure of 60 MPa were measured by contact profilometer. They reached the depths of 3.02 mm and 1.51 mm at the overmolding temperature of 280 and 230 °C respectively. These values were correlated with sink marks indexes simulated in Moldflow software at the same conditions. Based on the simulated and measured results the optimal process parameters with injection temperature of 200 °C and packing pressure of 25 MPa were proposed. Simulation showed a positive effect of optimized parameters on sink marks minimizations. Sink marks indexes decreased of 20 % and 53 % compared to injection molding temperatures of 230 and 280 °C respectively. Maximal depth of sinks marks decreased to the value of 1.00 mm at optimized injection overmolding process parameters.