• Design & Manufacturing
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• 제11권3호
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• pp.13-18
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• 2017

The injection molding analysis of VCM (Voice Coil Motor) housing for smart phone cameras were performed. We conducted the analysis in terms of injection molding pressure, the formation of weld lines, flow marks, and flow patterns. The goal of the analysis was targeted for the prediction of the optimal gate locations. Because the quality of VCM housing is strongly dependent on the precise control of the camera lens by its nature, we focused on the lens guiding lanes in the VCM housing. We first calculated the maximum injection molding pressure in terms of the filled volumes. The injection molding pressure were calculated within 146MPa at about 90% volume filled. We also investigated the possibility of the occurrence of design-related defects such flow marks, weld lines. Filling patterns regarding the design of the gate locations were delineated to find the weld lines. Throughout the simulations, the final deformations of the lens guiding lanes for the VCM housing were calculated. The deformations distribute ranging from $0.5{\mu}m$ to $2.50{\mu}m$, which were used to find the optimal design of the gates.

• Design & Manufacturing
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• 제15권1호
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• pp.1-7
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• 2021

The position of the gate is one of the important factors for optimal injection molding. This is because inappropriate gate positions cannot fill the cavity uniformly, which can lead to defects such as contraction. In this study, CAE was performed on hot runner injection molding of the washing machine base and plasticity was compared by changing gate position from existing gate position. A total of two alternatives have been applied to compare the plasticity of the washing machine base according to its optimal gate position. The gate position of the improved molds and the gate position of the current mold is analyzed by injection molding analysis. The results of the fill time, the pressure at V/P switchover, clamping force, and deflection were compared. In washing machine base injection molding, the deflection was reduced by about 3.76% in the improved mold 2. In improved mold 1, the fill time during injection molding was reduced by 3.32% to enable uniform charging, and the clamping force was reduced by 31.24%. We have confirmed that the position of the gate can change the charging pressure and the clamping force and affect the quality and cost savings of the molded product.

• 한국정밀공학회지
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• 제20권2호
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• pp.25-32
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• 2003

Molding properties of etched surface pattern are presented. Injection molding has given attention on improving dimensional accuracy and productivity. However, the molding of etched surface pattern on plastic parts is not researched relatively for its additional values, which can meet design function and customer's attraction. Specimens, whose surface patterns are made by print-type etching, are investigated. The molding properties of surface pattern are estimated with roughness deviation of surface pattern on part and mold. The etching properties are related to physical properties of plastic materials and surface roughness of etched pattern. Also, flow mark and gate location can give influence on surface pattern molding. The experimental result can contribute to good molding of surface pattern in injection molding.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.357-358
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• 2006

Importance of using an injection molding analysis has been increased. However the application of it has not been increased because the results of analysis do not sometime match to practical molding. Therefore, the difference of flow analysis and practical molding should be decreased. This study presents reasons of the difference for the location of weld-line in the flow analysis and practical molding on automobile bumper molding.

• Design & Manufacturing
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• 제2권3호
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• pp.16-21
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• 2008

In recent, the demands of household cases and disposable products is increased significantly because a living standard of newly-emerging nations was risen. Therefore, multi-cavity mold and stack mold for the realization of high-productivity have been researched in forefront nations. In this paper, CAE analysis for minimizing the mold core deformation was performed. Finally, 64 cavities injection mold for molding cap which has the insert-type core was fabricated according to the result of CAE analysis.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.75-76
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• 2008

• Design & Manufacturing
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• 제17권3호
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• pp.55-60
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• 2023

The fiber-reinforced plastics and cellular injection molding process can be used to efficiently reduce the weight of battery housing components of mild hybrid electronic vehicles(MHEV) made of metal. However, the fiber orientation of fiber-reinforced plastics and the growth of foaming cells are intertwined during the injection molding process, so it is difficult to predict the mechanical properties of products in the design process. Therefore, it is necessary to evaluate the mechanical properties of the materials prior to the efficient stiffness design of the target product. In this study, a study was conducted to evaluated the mechanical properties of fiber reinforced cellular injection-molded specimens. Two types of fiber-reinforced plastics that can be used in the target product were evaluated for changes in tensile properties of cellular injection-molded specimens depending on the foaming ratio and position from the injection gate. The PP and PA66 specimens showed a decrease of tensile modulus and strength of approximately 30% and 17% depending on the foaming ratio, respectively. Also, the tensile strength decreased approximately 26% and 17% depending on the position from the injection gate, respectively. As a result, it was confirmed that the PP specimens have a significantly mechanical property degradation compared to the PA66 specimens depending on the foaming ratio and position.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4411-4417
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• 2015

플라스틱 제품의 사출금형을 위한 게이트 위치의 최적 설계는 다양한 설계에 대한 3차원 사출성형 분석으로 도출할 수 있다. 이 논문은 사출금형에서 게이트 위치의 영향에 관한 연구이다. 게이트 위치는 플라스틱 제품의 생산성과 품질에 결정적인 영향을 미친다. 논문의 목적은 사출기를 사용한 자동차 에어 클리너 상부커버의 제조과정 중에 수지충전, 웰드라인, 사출압력에 대한 게이트의 영향을 분석하기 위한 것이다. 따라서 이 논문에서 이러한 문제들을 분석하기 위한 게이트의 위치는 4가지 경우로 변화를 주었다. 논문에서 각각의 게이트 위치 변화를 고려한 CAE 시뮬레이션은 사출금형공정에서 제품에 나타나는 결함의 원인을 예견하기 위하여 수행되었다.

• 대한기계학회논문집A
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• 제34권10호
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• pp.1513-1519
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• 2010

최근 고품질 제품 생산을 위한 방법으로 센서를 이용한 사출공정모니터링 시스템이 적용되고 있다. 그러나 마이크로 금형, 광학용 금형 및 구조가 복잡한 금형에는 센서 설치가 어렵기 때문에, 공정 모니터링 시스템이 적용되기 어려운 단점이 있다. 본 연구에서는 금형과 사출성형기 노즐의 압력 을 측정하여 공정 모니터링 데이터의 정량적 지수를 정의하고, 성형품 중량에 대한 상관분석을 수행하여 노즐에 설치된 압력센서의 공정모니터링 적용성을 알아보았다. 또한 공정모니터링 데이터를 분석하여 다단사출속도, 보압 및 제한 사출 압력의 영향에 따른 사출성형기의 공정 제어 특성도 알아보았다.

• 대한기계학회논문집
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• 제17권6호
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• pp.1465-1477
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• 1993

본 연구에서는 분말혼합체의 특성인 항복응력을 포함한 Generalized Newtonian Fluid의 구성 방정식을 도입하고 미끄럼현상을 고려한 신소재의 사출성형 충전과정 해석용 CAE(computer aided engineering)시스템을 개발하였다. 수치모사를 위한 수치해석방법으로는, 유한요소법(finite element method)과 유한차분법(finite difference method)을 함께 사용하였다. 유한요소법과 검사체적법(control volume technique) 을 병용하여 유동의 진행을 수치모사 하였으며, 유한차분법을 사용하여 온도분포를 계산하였다.