• Design & Manufacturing
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• v.2 no.3
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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.

• Design & Manufacturing
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• v.2 no.5
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• pp.5-10
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• 2008

Recently, ultra precision and light-weight micro products are needed in various industries. Injection molding products with metal insert material is often satisfied with light-weight and precision simultaneously. The researches on macro-size insert deformation have been performed but, a research on micro-size insert is meager. In this paper, the injection molding product with $300{\mu}m$ thin foil insert is designed and insert injection molding process is performed. Finally, the deformation of thin foil insert is analyzed according to insert feature and gate length.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.4
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• pp.335-342
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• 2014

This paper describes the forming conditions of smart-phone curved glass using the glass molding system with force applying system. The force applying system is composed of a body, a motor and gear, a rectilinear movement structure, a force sensor, a LVDT sensor (Linear Variable Differential Transformer), a up and down moving block, and so on. The glass molding system for characteristic test to find the forming conditions consists of the force applying system and a chamber, a metallic mold, a upper heater, a lower heater and so on. The characteristic test for forming conditions of smart-phone curved glass was carried out at forming temperature $620^{\circ}C$ and $650^{\circ}C$ using the glass molding system. As a result of the characteristic test, the forming conditions of curved glass could be found, and it is thought that the conditions can be used to apply to the system for producing in large quantities.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.518-520
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• 2011

금속분말 쾌속조형법의 한 종류인 DMLS 공정은 사출성형품의 균일한 냉각이 가능한 3차원 냉각시스템을 포함한 코어, 캐비티 제작이 가능하다. 그러나, 코어 및 캐비티 내 미세형상의 경우 DMLS로 제작하기에는 난해하므로 별도 미세 절삭가공을 통해 제작할 필요가 있다. 따라서, 본 연구에서는 DMLS금형강 소재의 미세 절삭가공 특성을 분석하고자 하였으며, 이를 위하여 HIP 공정 적용 전 후 DMLS금형강 소재를 대상으로 미세 절삭가공 실험을 수행하고 버 발생 및 공구마모 경향을 분석하였다. 실험 결과 HIP 적용 전 시편이 강도 및 조직측면에서 미세 절삭가공에 상대적으로 유리함을 확인할 수 있었다.

• Transactions of Materials Processing
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• v.20 no.8
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• pp.534-539
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• 2011

The production technology is the basic of manufacturing for various materials and components. This technology can influence the quality and productivity of leading export products such as automobile, ship, and electronic device. Besides, the production technology is very useful to apply to other manufacturing fields and has a great ripple effect. However, it is very difficult to make the production technology into standardization and knowledge-based database because the production technology is dependent in hands-on experience. In this study, the knowledge-sharing platform for the molding & forming technology which is a branch of the production technology is introduced. This platform is web-based system and has the knowledge authoring tool technologies storage, semantic database, and web portal service. Therefore, the molding & forming technology can be shared and spread easily by the knowledge-sharing platform.

• Design & Manufacturing
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• v.16 no.4
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• pp.24-33
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• 2022

Fiber-reinforced plastics(FRPs) have excellent specific stiffness and strength, so they are usually used as automotive parts that require high rigidity and lightweight instead of metal. However, it is difficult to predict the mechanical properties of injection molded parts due to the fiber orientation and breakage of FRPs. In this paper, the fiber orientation characteristics and mechanical properties of injection molded specimens were evaluated in order to fabricate automotive transmission side covers with FRPs and design a rib structure for improvement of their rigidity. The test molds were designed and manufactured to confirm the fiber orientation characteristics of each position of the injection molded standard plate-shaped specimens, and the tensile properties of the specimens were evaluated according to the injection molding conditions and directions of specimens. A gusset-rib structure was designed to improve the additional structural rigidity of the target products, and a proper rib structure was selected through the flexural tests of the rib-structured specimens. Based on the evaluation of fiber orientation and mechanical characteristics, the optimization analyses of gate location were performed to minimize the warpage of target products. Also, the deformation analyses against the internal pressure of target product were performed to confirm the rigidity improvement by gusset-rib structure. As a result, it could be confirmed that the deformation was reduced by 27~37% compared to the previous model, when the gusset-rib structure was applied to the joining part of the target products.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.514-517
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• 2011

본 연구에서는 사각형태 화장품 케이스 사출성형 시 발생되었던 수지 미성형 불량을 해결하기 위하여 사출성형해석 기술을 통해 성형품 형상변경 및 사출금형 내 유동 시스템 수정방안 도출을 수행하였다. 대상제품인 사각형태 화장품 케이스는 상측부 케이스로서 케이스 외관에 게이트 및 취출흔적이 남지 않아야 함에 따라 측면부 게이트 적용으로 유동거리가 길어져 미성형 불량이 다수 발생하는 제품이다. 따라서, 수지 유동성 향상과 더불어 효율적인 보압전달을 통하여 수지 충전 및 변형발생 저감을 위하여 성형품 형상변화 및 유동시스템 변화에 따른 사출성형해석을 수행하고 결과를 고찰하였다. 이로써 최종적으로 수지 미충전으로 인한 미성형 불량을 제거하고 성형품 변형을 줄일 수 있는 수지유동시스템 수정방안을 제시하였다.

• Design & Manufacturing
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• v.17 no.3
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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.

• Design & Manufacturing
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• v.2 no.3
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• pp.10-15
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• 2008

Recently, mobile-phone with camera module has an absolute majority in the released mobile-phones. For this trend, High precision of the plastic subminiature barrel which is the core part is needed significantly because the camera module of mobile-phone must have high performance. Therefore, Structural stability of the injection mold for plastic subminiature barrel has to be guaranteed. In this paper, structural analysis of injection mold for plastic subminiature barrel is performed. Finally, the deformation trend and stability of injection mold core are analyzed.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.261-264
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• 2000

The objective of this work was to characterize mechanical properties of thermoplastic composites for various forming condition in compression molding. Randomly oriented long glass fiber reinforced polypropylene(PP) was used in the work. The composite materials contained 20%, 30%, and 40% glass fiber by weight. Compression molding was conducted to make the test specimen. Dimensional stability was measured on each forming condition with the spring-forward angle. Tensile test was conducted to characterize mechanical properties of formed parts in various forming conditions.