• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.703-704
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• 2013

• 한국정밀공학회지
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• 제12권3호
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• pp.110-118
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• 1995

The filling phase analysis of the injection molding process for thermoplastics was applied to predict pressure, themperature and shear stress in the test mold, and the results were compared with the experiment using 30% glass fiber added ABS resin. The finite difference method was used in the analysis considering the effects of heat transfer between molten polymer and mold wall, and also frictional heating by shear flow. The analysis results were considered as a method to improve the quality and the productivity of injection molding process. Using the analysis results, the molding factors such as mold-ability of polymers, performance of injection molding machine, positioning of gate and dimendsioning of runner in the injection molding process can be estimated at the design stage of mold for good quality and productivity.

• 한국정밀공학회지
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• 제31권1호
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• pp.9-13
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• 2014

The molding process can be divided into five separate steps: plastification, injection, holding, cooling, and finally ejection. In the plastic injection molding, the effect factor such as mold temperature, injection speed, packing pressure and inhomogeneous cooling under packing process affects both the article dimension and physical characteristics. Especially, the packing pressure is the most critical factor to affect molded articles quality among the packing parameters. In this paper, the CAE simulation considering the molding condition is performed to predict the faulty cause which appears in the packing process between cavities of injection molding machine. From the results of CAE simulation, the packing phenomena according to the product form and the gate position was investigated to improve the article quality and minimize the various molding defects. The effect of packing pressure and gate number on the injection molding was discussed.

• 동력기계공학회지
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• 제4권3호
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• pp.81-85
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• 2000

The surface gloss of the injection molded part is one of the most significant point for evaluation the quality of products appearance. The effects of molding condition on the gloss of HIPS(High Impact Poly Styrene) molded part were investigated in this work. The measurements of gloss on the surface of molded part were carried out with different melt temperature, mold temperature, injection pressure and holding pressure. We observed the result of HIPS gloss compared with our's previous ABS study. The more melt and mold temperature increased, the brighter the gloss increase. Holding and injection pressure had little effect on the gloss. The gloss was effected in order of melt temperature, mold temperature, injection pressure, holding pressure.

• Design & Manufacturing
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• 제9권2호
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• pp.10-15
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• 2015

The water has been the suitable for the cooling medium until now. But the water as cooling medium seem to have the limit for high speed injection. The steam plastic molding injection use the steam as the medium when raise the mold temperature. The weld line has been the major quality problems in a plastic injection parts to be difficult to be solved. These problems in injection-molded plastic parts are difficult to find the reason because these issues are usually in tradeoff realtions with each other. The purpose of this paper is to obtain the optimum injection moulding condition for improving the quality of plastic injection parts and to inquire the productivity improvement with the measured cycle time by steam plastic moluding injection. Based on these numerical results, the guidelines of mould design and injection processing condition were established. As a result, the improvement of quality and the reduction of cycle time was achieved.

• Journal of Advanced Marine Engineering and Technology
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• 제34권2호
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• pp.289-295
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• 2010

플락스틱 재료를 사용한 가공법 중에서 가장 보편적인 가공법이 사출성형이다. 플라스틱 재료의 활용도는 지속적으로 증가하고 있으며, 신소재 등의 개발로 그 적용범위 또한 확대되고 있다. 사출성형에서 수축현상은 수지의 종류, 즉 결정성 수지인지 비결정성 수지인지에 따라 크게 다르게 나타나며 사출성형시의 운전조건에 따라서도 다르다. 본 연구에서는 Al합금으로 제작되고 있는 인라인 스케이트의 프레임을 플라스틱 재료로 대체하기 위한 최적화 공정에 관한 것이다. 금형설계 전 해석을 통하여 성형공정이 최소화되는 런너와 게이트의 치수와 형상을 결정하겠다. 런너와 게이트의 치수 변화에 따른 제품의 사출성형성을 알아보겠다. 본 연구의 시뮬레이션에서는 사출성형해석용 소프트웨어인 Moldflow를 이용해서 해석을 수행하였다.

• Tribology and Lubricants
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• 제18권5호
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• pp.345-350
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• 2002

Recently, as the development of manufacturing technique on SMC(sheet molding compound), various numerical and experimental approaches to injection and compression molding have been investigated. Injection and compression molding, however, has so various cases with complicated boundary condition that it is difficult to analyze mold characteristics precisely. In addition, since a slight change in process variables can significantly change the resulting mold thickness, a proper design is important to compression molding process. Therefore, in this study, the effects of various parameters on compression molding process have been investigated using FEM(finite element method) to formulate the melt front advancement during the mold filling process. To verify the results of present analysis, they are compared with those of reference. The results show a strong effect of initial charge volume, injection time and pressure as a result of variations in the rectangular charge shape.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.882-885
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• 2002

Magnesium alloys are very attractive materials for appling to the development of autemobile parts or electric goods where light weight and higher stiffness. Due to higher ratio of strength vs. weight and stillness vs. weight, various magnesium alloys are well applied in much weight saving design applications though extrusion or die-casting process. However for the requisites of higher strength and weight savings, some new fabrication processes has been and it can be realized though the aid of injection modeling technology. To obtain the parametric data base for the injection molding process, various experiments were executed for AZ91D magnesium alloy. This paper propose the optimum condition of injection temperature, first and second pressure. the process was lined-up successfully often changing the injection unit. fluid pressure system from the conventional plastic injection molding process.

• 소성∙가공
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• 제15권8호
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• pp.628-632
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• 2006

The gate mark in injection molded part is a kind of surface defects. The formation of gate mark has been investigated in this study. SEM photographs and surface roughness have been examined to study gate mark. The specimens were molded for various injection conditions, such as injection temperature, mold temperature, and injection speed. Gate diameter and mold surface condition were also molding variables. Gate marks were reduced as injection speed and mold temperature increased. Gate diameter and injection temperature did not affect the gate marks. No etching of mold surface showed no gate marks for any molding conditions.

• 한국산학기술학회논문지
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• 제13권12호
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• pp.5709-5715
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• 2012

플라스틱 소재를 사용한 사출성형부품은 차량 경량화뿐만 아니라 충격흡수를 통한 운전자와 보행자 보호, 제품 디자인의 자율성등의 우수한 장점을 가지고 있어 그 사용량이 급속히 증가하고 있다. 유리섬유함유 플라스틱재료를 이용한 레귤레이터 레일의 사출성형시 불량률최소화를 위해 유한요소해석과 실험계획법을 사용하여 성형공정중의 휨변형량(warpage)과 수축변형를 최소화할 수 있는 최적의 성형조건을 제시하고자 한다. 또한 유리섬유의 유동성과 냉각효율의 확보를 위해 최적의 게이트 및 런너방식을 설정한다. 사출금형을 제작하여 제품을 성형제작한 후 휨변형등의 성능확인을 통해 해석방법의 유효성과 최적화의 실효성을 확인하고자 한다.