Article
  • Cell Formation and Dimensional Stability According to Molding Conditions in Foam Injection Molding of PP Using a Chemical Blowing Agent
  • Hai-Yang Yu, Geun-Tae Park, Soo Hyung Ban*, and Min-Young Lyu

  • Department of Mechanical Information Engineering, Graduate School of Seoul National University of Science and Technology 232 Gongneung-ro, Nowon-gu, Seoul 01811, Korea
    *Samsung Electronics Co. Ltd., 129 Samsung-ro, Yeongtong-gu, Suwon 16677, Korea

  • 화학발포제를 이용한 PP의 폼 사출성형에서 성형조건에 따른 셀의 형성 및 치수 안정성
  • 우해양 · 박근태 · 반수형* · 류민영

  • 서울과학기술대학교 기계정보공학과, *삼성전자

  • Reproduction, stored in a retrieval system, or transmitted in any form of any part of this publication is permitted only by written permission from the Polymer Society of Korea.

Abstract

Foam injection molding was performed by adding a chemical blowing agent to PP to form a cell inside the plastic specimen. Cell formation, cell density, and dimensions of the specimen were observed while changing the injection temperature, injection speed, and back pressure of the heating cylinder. The higher the injection temperature, the better the cell formation, and the formation of the cell was the best when the injection speed was the highest at the high injection temperature. The cell density was very high when the back pressure in the heating cylinder of the injection molding machine was low, however the generation of cells significantly decreased as the back pressure increased. In the case of foam injection molding using a chemical blowing agent, it was very important not only to prevent the generated gas from escaping out of the mold during filling stage, but also to prevent it from escaping from the heating cylinder to the outside. The dimensions of the foamed specimens were very stable regardless of cell density variations in various molding conditions.


플라스틱 시편의 내부에 셀을 형성하게 하기 위해 PP에 화학발포제를 첨가하여 폼 사출성형을 수행하였다. 사출온도, 사출속도, 그리고 가열 실린더의 배압을 변화하면서 셀의 형성과 셀 밀도 그리고 시편의 치수를 관찰하였다. 사출온도가 높을수록 셀의 형성이 잘 되었으며 높은 사출온도에서 사출속도가 클 때 셀의 형성이 가장 좋았다. 사출기의 가열 실린더 내의 배압이 낮을 때 셀 밀도가 매우 높았으나 배압이 증가함에 따라 셀의 생성이 현저히 감소하였다. 화학발포제를 이용하여 폼 사출성형을 하는 경우 발생된 가스가 충전 중에 금형 밖으로 빠져나가지 않도록 하는 조건 뿐만 아니라 가열 실린더 내에서 외부로 빠져나가지 않는 조건이 매우 중요하였다. 폼이 형성된 시편의 치수는 다양한 성형조건에서 나타나는 셀의 밀도 변화와 관계없이 매우 안정된 치수를 보였다.


Keywords: foam injection molding, chemical blowing agent, cell formation, cell density, dimensional stability.

  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2023 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 2023; 47(2): 249-256

    Published online Mar 25, 2023

  • 10.7317/pk..2023.47.2.249
  • Received on Jan 11, 2023
  • Revised on Jan 30, 2023
  • Accepted on Jan 30, 2023

Correspondence to

  • Min-Young Lyu
  • Department of Mechanical Information Engineering, Graduate School of Seoul National University of Science and Technology 232 Gongneung-ro, Nowon-gu, Seoul 01811, Korea

  • E-mail: mylyu@seoultech.ac.kr