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Language: korean

Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

Publication history: Received September 27, 2010
Accepted October 30, 2010

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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고무사출성형의 적정설계

Optimum Design of Rubber Injection Molding Process

이은주 임광희^1† 부타이지양¹

Eun Ju Lee Kwang-Hee Lim^1† Vu Tai Giang¹

경북대학교 화학공학과, 702-701 대구광역시 북구 산격동 1370번지 ¹대구대학교 화학공학과, 712-714 경북 경산시 진량읍 내리리 15

Department of Chemical Engineering, Kyungpook National University, 1370, Sankyeok-dong, Buk-gu, Daegu 702-701, Korea ¹Department of Chemical Engineering, Daegu University, 15 Naeri-ri, Jillyang-ep, Gyungsan-si, Gyeongbuk 712-714, Korea

khlim@daegu.ac.kr

Korean Chemical Engineering Research, February 2011, 49(1), 47-55(9), NONE Epub 9 February 2011

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Abstract

K사의 고무 사출성형에 있어서 애로사항인 등속조인트 부트(boots)의 크랙(crack) 발생 등의 문제점을 해결하기 위하여, 상용 CAE 프로그램인 MOLDFLOW(Ver. 5.2)를 이용한 전산모사를 수행하여 적정금형설계를 도출하고 적정작업조건을 구축하였다. 그 결과 크 의 발생 원인은 크 이 발생하는 위치에 형성되는 weld 및 meld line의 형성 때문이고, 또한 크 이 발생하는 위치에서의 가류(curing)가 불완전한 것이 확인되었다. 이와 같은 weld 및 meld line의 형성을 방지하기 위해서 게이트(gate)의 위치를 변경하고 최적위치에 설계함으로써, 유동선단(melt front)의 충돌 또는 수지흐름의 만남을 최소화하는 충전패턴(fill pattern)을 형성하고 부트 안쪽 하단의 크 발생을 방지하였다. Weld 및 meld line과 에어트랩(air trap) 불량이 가장 큰 게이트 위치는 각각 최적 게이트위치를 기준으로 서로 정반대 방향임이 관찰되었다. 한편 몰드(mold)의 온도를 170 ℃로 유지하게 함으로써 크 이 발생했던 위치에 가류조건을 만족시켰다.

The optimum mold design and the optimum process condition were constructed upon executing process simulation of rubber injection molding with the commercial CAE program of MOLDFLOW (Ver. 5.2) in order to solve the process-problems of K company relating to cracks, which occurs at the inner cavity wall of C. V. joint boots. As a result it was confirmed that the real cracks occurs at the exactly same position of the cavity as exhibits the defects of weld and meld line and unsatisfactory curing according to the result of simulation. In order to prevent the occurrence of weld and meld line at the defect-position, the location of gate was altered to the optimum position of the cavity. Consequently the filling pattern was established to minimize the degree of the melt-fronts confronting or the melt-flows melding to prevent the occurrence of weld and meld line at the defect-position. It was observed that both gate-positions to maximize the degree of the formation of weld and meld line and air traps are located, respectively, in opposite direction_x000D_ each other with reference to the optimum gate position. In addition, the temperature of mold was raised by 10 o℃ and maintained at 170 ℃ for satisfactory curing.

Keywords

Rubber Injection Molding C. V. Joint Boots Crack Process simulation Weld and Meld Line Air Trap Curing

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