• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1483-1486
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• 2003

Injection mold is a manufacturing process used to produce the various parts of complicated shape at a low cost. Many factors such as, section shape, resin and mold temperature, filling time, etc, affect on the quality of injection part during injection molding process. The precent study, was carried out the shrinkage analysis of shoes injection mold to optimize runner shape based on filling and packing pressure with MoldFlow. Taguchi design and analysis of variance are used to optimize injection mold design.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2005년도 ISMP
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• pp.67-88
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• 2005

Mold-Flow 3 Die Stack CSP of Mold array packaging with different Gate types. As high density package option such as 3 or 4 die stacking technologies are developed, the major concerning points of mold related qualities such as incomplete mold, exposed wires and wire sweeping issues are increased because of its narrow space between die top and mold surface and higher wiring density. Full 3D rheokinetic simulation of Mold flow for 3 die stacking structure case was done with the rheological parameters acquired from Slit-Die rheometer and DSC of commercial EMC. The center gate showed severe void but corner gate showed relatively better void performance. But in case of wire sweeping related, the center gate type showed less wire sweeping than corner gate types. From the simulation results, corner gate types showed increased velocity, shear stress and mold pressure near the gate and final filling zone. The experimental Case study and the Mold flow simulation showed good agreement on the mold void and wire sweeping related prediction. Full 3D simulation methodologies with proper rheokinetic material characterization by thermal and rheological instruments enable the prediction of micro-scale mold filling behavior in the multi die stacking and other complicated packaging structures for the future application.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.603-607
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• 2002

Cavity pressure is a factor of what is occurring inside the mold and is used as one of the process parameters that control the overall injection molding cycle. The insight of cavity pressure is able to predict part quality and optimum process condition. In this paper, it is adapted ejector pin sensor to measure the cavity pressure and investigates the flow balance and the cavity pressure according to different runner thickness for adjusting the flow balance. Flow balance is very important to have not the poor results such as flash and warpage in the family mold. This paper predicted flow balance and cavity pressure using CAE analysis tool and compared with the test results. The results of analysis and test have a good agreement with the cavity pressure profile and flow pattern of the test.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.155-158
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• 2008

Flow imbalance among the cavities was often observed in multi-cavity mold. The flow imbalance affects on the dimensions and physical properties of molded articles. First of all, the origin of flow imbalance is geometrical imbalance of delivery system. However, even the geometry of delivery system is balanced the cavity imbalance is being developed. This comes from the temperature distribution in the cross-section of runner, which is affected by the operational conditions. In this study, experimental study of flow imbalance has been conducted for various injection speeds. This study also suggests new runner design to eliminate flow imbalance in multi-cavity injection mold. Simulation and experimental results showed suggested new designed runner could eliminate or reduce flow imbalance in multi-cavity injection mold.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.329-332
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• 2008

Flow imbalance among the cavities was often observed in multi-cavity mold. The flow imbalance affects on the dimensions and physical properties of melded articles. First of all, the origin of flow imbalance is geometrical imbalance of delivery system. However, even the geometry of delivery system is balanced the cavity imbalance is being developed. This comes from the temperature distribution in the cross-section of runner, which is affected by the operational conditions. In this study, experimental study of flow imbalance has been conducted for various injection speeds. This study also suggests new runner design to eliminate flow imbalance in multi-cavity injection mold. Simulation and experimental results showed suggested new designed runner could eliminate or reduce flow imbalance in multi-cavity injection mold.

• Elastomers and Composites
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• 제49권3호
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• pp.220-224
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• 2014

자동차 타이어의 트레드는 노면과 직접적으로 접촉하며 제동력, 구동력, 소음 등 중요한 역할을 한다. 트레드는 많은 그루브로 이루어져 있는데 고무의 형상을 형성하는 가류 공정에서 불량이 발생하게 되면 트레드의 기능이 저하되어 자동차 성능의 문제로 이어지게 된다. 본 논문은 CAE 해석을 통하여 가류 공정 중 구체적인 고무의 흐름을 분석하였다. 트레드 형상에 따라 고무 흐름의 편차가 발생하기 때문에 형상에 따른 트레드의 고무가 금형에 접촉되는 순서와 속도 그리고 고무의 흐름을 관찰하였다. 트레드의 형상에 따라서 고무가 금형에 안착되는 양상이 다르게 나타났으며 고무의 흐름에 큰 변화를 주는 것을 확인할 수 있었다.

• 한국전산유체공학회지
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• 제4권2호
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• pp.47-56
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• 1999

We developed a computer program to simulate the flow field in the presence of electro-magnetic fields. The steady, two-dimensional conservation equations for mass and momentum were solved simultaneously with Maxwell equations for electro-magnetic fields. Using this program, a numerical analysis was carried out to analyze the fluid flow in the continuous casting mold with electromagnetic brake. The effects of magnetic fields size, nozzle angle and EMBR yoke position on the flow fields in the continuous casting were investigated in the present study. The flow fields with EMBR were compared with those without EMBR. We also investigated the distribution of tracer concentration as a function of time in order to calculate their residence time in the mold with EMBR. By controlling the flow fields properly using EMBR, we can prevent the direct flow impaction on the wall which can give a damage on the mold surface and reduce surface defects of stainless steel sheet products.

• 소성∙가공
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• 제15권1호
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• pp.15-20
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• 2006

The rapid thermal response (RTR) molding is a novel process developed to raise the temperature of mold surface rapidly to the polymer melt temperature prior to the injection stage and then cool rapidly to the ejection temperature. The resulting filling process is achieved inside a hot mold cavity by prohibiting formation of frozen layer so as to enable thin wall injection molding without filling difficulty. The present work covers flow simulation of thin wall injection molding using the RTR molding process. In order to take into account the effects of thermal boundary conditions of the RTR mold, coupled analysis with transient heat transfer simulation is suggested and compared with conventional isothermal analysis. The proposed coupled simulation approach based on solid elements provides reliable thin wall flow estimation for both the conventional molding and the RTR molding processes.

• Design & Manufacturing
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• 제13권1호
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• pp.25-30
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• 2019

This paper presents the design strategy for the optimal RTM molds of Carbon Fiber Reinforced Plastic (CFRP) by carbon fiber draping and resin flow simulation. First, the mold shape and molding condition were determined considering the undercut and die face of the product in the draping simulation, which made the preliminary shape of the product by compressing the carbon fiber. After that, the diffusion behavior during the injection of resin in the mold was predicted by the resin flow simulation. Finally, the optimal mold shape was designed by selecting the locations of resin injection port and vent based on total results of simulations. In this paper, the mold of automotive side mirror case was selected as the representative product. Also, the actual mold was manufactured based on the simulation design to confirm the practicality of it. This study is expected to contribute to the industry as a technology to improve the reliability and productivity of CFRP producted by RTM process.

• 한국생산제조학회지
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• 제23권6호
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• pp.561-568
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• 2014

Injection molding industries realize the necessity of developing family molds to improve competitiveness. One of the primary causes of manufacturing defective products is the imbalance of flow in a family mold. In this study, the family mold of a shelf for refrigerators is analyzed by using CAE software. First, the flow balance, clamping force, and injection pressure are analyzed for different gate diameters of two cavities. Second, the flow balance, clamping force, and injection pressure are improved when the two gate valves are open at different times. Finally, the results of filling analysis are compared with the test injection product.