• Design & Manufacturing
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• v.12 no.1
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• pp.31-35
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• 2018

The peltier thermoelectric module are used to cool the heat generated by electronic equipment. In order to increase the efficiency of the peltier thermoelectric module, the heat must be released to the outside. A heat sink is used to discharge such heat to the outside. in this paper, two types of heat sinks with internal tunnels were designed. And the heating and cooling performance of the heat sink with internal tunnel structure was compared and analyzed through ANSYS. The heat sink of the A type had better heat transfer than the heat sink of the B type. Which is about 70% improved.

• IE interfaces
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• v.13 no.2
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• pp.157-165
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• 2000

In this paper, an efficient method is proposed to place the cooling lines(CLS) and ejector pins(EPS) of mold design. The other components of mold, except CLS and EPS, can be generated automatically by batch processing. But the placements and sizes of CLS and EPS depend on the shapes of a part, so that the design works of CLS and EPS should be processed interactively. Using the pre-defined reference points, the positions of CLS and EPS can be determined interactively. By the proposed method, the interference occurred during placing CLS and EPS can be avoided, and the proper lengths of them can be calculated automatically. The information of the positions and lengths are stored in BOM database for generating a machining data. The proposed method is implemented with Unigraphics API functions and C language, tested on Unigraphics V15.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.150-151
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• 2014

A mold of free-form concrete segment can be used only one time. Thus, the construction duration and cost are increased. The materials of the mold such as wood and metal have limitations due to the implementation and reuse. The review of the material of the mold for free-form concrete segment is needed to reduce duration and production cost. Phase change material can be used both to implement free-shape by heating and to produce mold after cooling. After using Phase change material can be re-used to mold by heating. The scope of this study is many kind of phase change materials for molding. The aim of this study is to analyze the phase change materials for production of changable mold for free-form concrete segment. In this study, the paraffin wax that is melted at 64℃ was selected by considering both the energy efficiency and the weather of Korea.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.73-76
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• 2004

High-temperature Superconductor(HTS) tubes were fabricated in term of different processing variables such as preheating temperature, speed of mold rotation and cooling rate by centrifugal forming method. For powder melting by induction the optimum range of melting temperatures and preheating temperature were $1050^{\circ}C{\sim}1100^{\circ}C$ and $550^{\circ}C$ for 30min, respectively. The mould roating speed was 1000rpm. A tube was annealed at $840^{\circ}C$ for 72hours in oxygen atmosphere. The plate-like grains were well developed along the roating direction and typical grain size was about more than $40{\mu}m$. It was found that Ic values increased with increasing the preheating temperature and speed of mold rotation. While Ic decreased with increasing the cooling rate. The measured Ic in $50mm{\times}70mm{\times}2.5mm$ tube was about 896Amp.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.5
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• pp.468-472
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• 2005

High-temperature Superconductor(HTS) tubes were fabricated in term of different processing variables such as preheating temperature, speed of mold rotation and cooling rate by centrigugal forming method. For powder melting by induction the optimum range of melting temperatures and preheating temperature were $1050{\circ}C{\sim}1100{\circ}C\;and\;550{\circ}C\;for\;30\; min$, respectively The mould roating speed was 1000 rpm. A tube was annealed at $840 {\circ}C$ for 72 hours in oxygen atmosphere. The plate-like grains were well developed along the loafing direction and typical grain size was about more than $40{\mu}$. It was found that Ic values increased with increasing the Preheating temperature and speed of mold rotation. While Ic decreased with increasing the cooling rate. The measured Ic in $50mm{\times}70mm{\times}2.5mm$ tube was about 896 Amp.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.11
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• pp.961-968
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• 2015

This study aims to develop an efficient mold structure for the injection molding of a subminiature lens, using shell-type runners instead of traditional cylindrical runners. While the shell runner has the advantage of shorter cooling time due to its thinner geometry, this smaller thickness causes an increase in injection pressure. In this study, the design of the shell runner was modified to contain multiple holes for the purpose of reducing injection pressure. Numerical analyses were performed for shell runners of various hole-shapes, and the resulting filling and cooling characteristics were discussed; the rhombic hole showed the best result for both filling and cooling characteristics. Subsequently, injection molding experiments were performed using an injection mold fabricated based on the rhombic design. The lens parts were successfully molded with highly-reduced cycle time and without degradation of part quality.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1818-1832
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• 1994

Transport process during solidification of an AI-CU alloy in a vertical annular mold of which inner wall is cooled is numerically simulated. A model which can take account of local density dependence on the solute concentration is established and incorperated in the analysis. Results show that thermally and solutally induced convections are developed in sequence, so that there is little interaction between them. Thermal convection effectively removes the initial superheat from the melt and vanishes as solidification proceeds from the cooling wall. On the other hand, solutal convection which is developed later over the meshy and the pure liquid regions leads to large-scale redistribution of the consituents. The degree of the initial superheating hardly affects overall solidification behavior except the early stage of the process, when the cooling rate is kept constant. Macrosegregation is reduced remarkably with increasing cooling rate, because not only the liquidus interface advances so quickly that time available for the solute transport is not enough, but also the interdendritic flow is strongly damped by rapid crystal growth within the mushy region.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.82-87
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• 2019

Recently, plastic materials have become more diversified, and the development of materials with excellent mechanical properties and plasticity has enabled wider application, miniaturization, and refinement of injection molded products. As a result, the utilization of these products in household goods, electronics, automotive parts, and aircraft parts is increasing in almost all industries. Injection molded parts are often used externally on finished commercial products. This means that the injection mold industry is very important to the value of these products. For this reason, the industry is performing research on the precision and efficiency of the injection molding process. In this study, we investigated the applicability of the core in core cooling method to the problem of product deformation due to temperature variation in existing injection mold designs. We also characterized the cooling performance of an injection mold when using this cooling method.

• Transactions of Materials Processing
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• v.17 no.5
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• pp.337-342
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• 2008

The injection molding process has high accuracy and good reproducibility that are essential for mass production at low cost. Conventional molding processes typically use the water-based mold heating and air cooling methods. However, in the nano injection molding processes, this semi-active mold temperature control results in the several defects such as air-flow mark, non-fill, sticking and tearing, etc. In order to actively control temperature of the molds and effectively improve the quality of the molded products, the novel nano injection molding system, which uses active heating and cooling method, has been introduced. By using the Peltier devices, the temperature of locally adiabatic molds can be controlled dramatically and the quality of the molded patterns can be improved.

• Design & Manufacturing
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• v.2 no.1
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• pp.21-26
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• 2008

In this research, jar die of cosmetic products which is difficult to produce variously was developed and can be obtain the productivity improvement by flexibility with two system which can control the die temperature. Flow analysis of jar was performed to find out the curvature radius of parts. In order to reduce thickness of jar, cycle time, deformation, uniform curvature of internal jar was maintained by rapid cooling. In external of dies, cooling channel, injection molding condition, die temperature control system were researched to make dies low temperature.