Elastomers and Composites

The Rubber Society of Korea (한국고무학회)
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An Investigation of Surface Appearance of an Injection-Molded Plastic Part with Various Induction Heating Conditions

고주파 가열조건에 따른 플라스틱 사출성형품의 표면특성 고찰

  • Sohn, Dong-Hwi (School of Mechanical Design and Automation Engineering, Seoul National University of Technology) ;
  • Seo, Young-Soo (School of Mechanical Design and Automation Engineering, Seoul National University of Technology) ;
  • Park, Keun (School of Mechanical Design and Automation Engineering, Seoul National University of Technology) ;
  • Lee, Kwang-Woo (Mobase Co., Ltd.)
  • 손동휘 (서울산업대학교 기계설계자동화공학부) ;
  • 서영수 (서울산업대학교 기계설계자동화공학부) ;
  • 박근 (서울산업대학교 기계설계자동화공학부) ;
  • 이광우 ((주)모베이스)
  • Published : 2009.12.31
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Abstract

High-frequency induction is an efficient way to rapidly heat mold surface by electromagnetic induction. In the present work, high-frequency induction heating is applied to injection molding of a mobile phone cover in order to eliminate weldlines by efficiently raising the mold temperature. Through the induction heating experiments, the maximum temperature of $143^{\circ}C$ is obtained on the mold surface in 3s of heating, which is higher than the glass transition temperature of the resin material. An injection molding experiment is then performed with the aid of induction heating, from which we can successfully remove all the weldlines of the mobile phone cover. The effect of induction heating conditions such as the heating power and the heating time on the surface appearance is experimentally investigated.

고주파 유도가열은 전자기 유도현상을 이용하여 금형표면을 비접촉 형태로 급속 가열할 수 있는 기술이다. 본 연구에서는 고주파 유도가열을 사용하여 사출금형의 표면을 급속으로 가열함으로써 휴대폰 사출성형품의 웰드라인을 제거하기 위한 연구를 수행하였다. 고주파 유도가열 실험을 통해 3초간의 가열로 금형 표면온도를 $143^{\circ}C$까지 가열함으로써 고분자수지의 유리전이온도 이상으로 급속 가열할 수 있음을 확인하였으며, 상기 고주파 유도가열을 적용하여 휴대폰 외장부의 사출성형을 실시하여 기존에 발생되었던 웰드라인을 성공적으로 제거할 수 있었다. 또한 유도가열시 가열조건(고주파 유도가열기 출력 및 가열시간)의 변화에 따른 웰드부 표면특성의 변화를 고찰하였다.

Keywords

References

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