Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


한국표면공학회지 (35권3호 113-120)

A Study on Improvement of Surface Qualify in Injection Molded Parts

사출금형제품의 표면향상에 관한 연구


한국산업기술대학교 기계공학과, 마이크로 부품 소재 연구소;
한국산업기술대학교 기계공학과, 마이크로 부품 소재 연구소;


Injection molded plastic parts have many surface defects. These include a weld line, sink mark, flow mark, gloss, shading, scratching etc. Because these surface faults are not aesthetically acceptable, plastic parts are produced through painting or texturing. The purpose of this paper is to develop paintless molded parts using a flow control method. Computer aided injection mold filling simulations were used in order to minimize the number of defects from injection molding. Based on the numerical results, FR(Flame Retardant) HIPS was developed and the guidelines for part design, mold design, and the processing conditions were established. The effects of cost savings, improvements in productivity, and recycling were considered by reducing the number of surface faults and eliminating the painting process.


Injection molded plastic parts;surface defects;paintless molded recycling;