• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1193-1194
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• 2011

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.131.2-135
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• 1999

This study focuses on part quality and cycle times under gas-assisted injection molding(GIM) of housing molded parts. The position of the gas channel was estabished near to parting line at the end of last locations to fill. Applied hot runner and valve gates the gas was introduced directly into the mold cavity via gas pin. As GIM was applied the introduced directly into the mold cavity via gas pin. As GIM was applied the conclusion reached as follows. I) The quality of appearance was improved by reducing sink marks and scratches of texture ii) The realibility was improved by preventing warpages and reinforcing rigidity through optimum gas channel layout iii)It is enable to use small size of injection molding machine step by step as GIM was accomplished low pressure and reduced clamp forces against CIM iv)The productivity were improved by reducing cycle times.

• 소성∙가공
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• 제12권8호
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• pp.738-743
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• 2003

The major problems of a plastic injection mould can be devided into two kinds, one is in mould another in injected parts. Most of defects of the former comes from mould design, such as, structure and working. The latter are weld line, warpage, sink mark, burning, flow mark, scratching, shading, black hole and so on. Most of problems in injection molding are difficult to find the reason because of complexity. The purpose of this paper is to improve the quality of plastic injection mould and parts with inquiring the counter plan and analizing troubles of the part of Flat TV Front Cover by flow control method and gas-assisted injection moulding. For minimizing defects of the injection moulded parts, computer aided simulation method for injection mould filling was used. Based on these numerical results, the guidelines of mould design and injection processing condition were established. As a result, the improvement of quality, such as minimizing surface defects of injection moulding parts and troubles in mould was achieved.

• 소성∙가공
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• 제21권1호
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• pp.36-41
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• 2012

Gas Assisted Injection Molding is a relatively new low-pressure injection molding technique that provides benefits such as reduced part warpage, excellent surface quality without shrink marks, greater design flexibility, etc. In the gas assisted injection molding process, the injected pressurized nitrogen gas flows through designed gas channels and forms hollow sections within the part. However, due to the characteristics of the gas, the design of the gas channels which are the paths for the injected gas is important in order to avoid defects such as gas blowout, fingering, etc. Therefore, in this study, the gas channel design for gas assisted injection molding of exterior display panels was conducted by examining the results of three CAE analyses. The designed gas channel was verified by conducting tryouts using a 450 ton injection molding machine with 3-stage pressure controlled gas kit. In addition, the hollow shapes which were formed by the gas with the installed gas channels were examined by examining the cross sections of the prototypes that were produced. As a result, it was found that exterior display panels can be produced without any defect by applying the gas assisted injection molding technique.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.201-206
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• 2003

Plastic injection mould have two kinds of trouble, one is in mould another in injection parts. Most of defects of the former take the cause in a design like in structure and working, the later weld line, transforming, sink mark, burning, flow mark, scratching, shading, black hole and so on. Most of problems of the later is difficult for making a clear definitely the reason of defects because of complexible. The purpose of this paper is to improve the quality of plastic injection mould and parts with inquiring the counter plan and rouble of the part of Flat TV Front Cover by flow control method and gas- assisted injection moulding. For minimizing defects from injection moulding parts, this paper was investigated with using computer aided injection mold filling simulations. Based on these numerical results, I established guidelines mould design and injection processing condition. As a results I got the improve of quality, minimizing surface defects moulded parts and troubles in mould.

• 한국산학기술학회논문지
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• 제16권11호
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• pp.7729-7735
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• 2015

플라스틱 사출성형제품은 금형을 제작하여 대량생산에 적합한 시스템으로서 두께가 두꺼운 자동차 핸들제품은 가스사출성형을 수행하는 것이 바람직하다. 가스사출성형은 용융된 원재료를 금형내로 충전시킨 후 질소가스를 주입하는 기술이다. 가스사출성형은 재료비절감, 품질향상 등 많은 장점을 가지고 있다. Moldflow소프트웨어를 활용하여 사출성형 공정을 해석하여 제품의 휨 변형을 최소하기 위한 게이트의 위치를 결정하였으며, 기존의 일반적인 PP재료로 가스사출 성형을 했을 경우 변형이 크게 발생되므로 미네랄이18% 함유된 PP 재료로 변경하여 사출제품의 휨 변형을 최소로 하는 것과 게이트의 위치를 변경하여 핑거링현상이 발생하는 트러블을 제거하는 것을 목적으로 하였다, 또한 가스 사출성형을 수행하였을 경우 원재료가 유입되고 난후 게이트를 기준으로 가스가 유입된 형상을 파악하기 위해 비교분석해 보았다. 본 연구를 통해 제품형상에 따른 두께의 변화와 가스사출성형을 수행하더라도 플라스틱의 재료에 따라 제품의 휨이 발생 될 수 있다는 것과 게이트의 위치가 제품의 트러블에 영향을 미친다는 것을 알 수 있었다.