• Design & Manufacturing
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• 제10권3호
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• pp.39-45
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• 2016

The purpose of this study is to build effective cooling circuit design in injection mold to improve glass fiber reinforced laptop computer cover plastics' transcription and gloss. Moldflow Insight and Ansys CFD CAE program used to verify efficiency and the experiment mold is precision machined and brazing soldered to make three-dimension cooling channel. The temperature of mold in injection test are fixed to $80^{\circ}C$ and $160^{\circ}C$. The result of this experiment is the improved surface quality of plastics with 85% improvement of transcription in high temperature mold.

• 소성∙가공
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• 제14권6호
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• pp.570-576
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• 2005

Powder Injection Molding(PIM) has recently been recognized as an advanced manufacturing technology for low-cost mass production of metal or ceramic parts of complicated geometry With this regards, design technology of dental scaler tip PIM mold, which has complex shape and small core pin (diameter=0.6mm), with the help of computer-aided analysis of powder injection molding process was developed. Computer-aided analysis for dental scaler tip mold was implemented by finite element method with non-Newtonian fluid, modified Cross model viscosity, PvT data of powder/binder mixture. Compter-aided analysis results, such as filling pattern, weldline formation, air vent position prediction were compared with experimental result, and eventually have been shown good agreement. The core pin (diameter=0.6mm) deflection analysis of dental scaler tip PIM mold during PIM filling process was also investigated before mold fabrication.

• Design & Manufacturing
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• 제16권2호
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• pp.60-65
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• 2022

In the pultrusion process for the CFRP (Carbon fiber reinforced plastic) rectangular pipe, the drawing device is eseential which can continuously produces products and draws the carbon fiber tow. In addition, since the degree of cure changes depending on the temperature and the temperature ditribution of the curing mold changes depending on the pultrusion speed, the temperature distribution of the curing mold under certain conditions must be studied before processing. In this study, in the pultrusion process using a closed impregnation method, which has several advantages compared to the general pultrusion process using a open bath impregnation method, the drawing force required to pull the carbon fiber tows and the temperature distribution of the curing mold was analyzed to design the drawing device and the curing mold efficiently.

• Design & Manufacturing
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• 제16권2호
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• pp.39-45
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• 2022

Sheet Metal Forming by Press Forming Process takes a lot of time and cost from mold design to manufacturing. Therefore, all of die-makers are continuously conducting research to reduce the number of mold processes or the size of blanks to reduce costs. In the case of Forming complex shapes such as automobile component, wrinkles and cracks occur, so draw beads are used. Draw beads play an important role in suppressing the inflow of materials and minimizing the size of blanks. Factors that affect material flow include draw bead, blank holding pressure, lubricant, and surface roughness of punch and die. Most of the factors affect friction. In this study, after classifying circular beads and rectangular beads in cylindrical drawing molds using the AutoForm analysis program, the factors affecting the material inflow were considered.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.181-185
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• 1990

In design of the plastic injection mold, most of drawings are composed of basic entities. It is very easy to produce many kinds of drawings by Group Technology. Group Technology is a technique In which part similarities are used to classify parts into part families according to either geometric shape and size or processing requirements. Almost data for the mold are decided during the assembly design. A system which shows a good interfaces between the design stage and producing part exploding Is developed using AutoCAD system and data conversion technique.

• 대한산업공학회지
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• 제19권4호
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• pp.71-86
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• 1993

In design stage of a plastic injection mold, basic entities of various kinds are introduced under the concept of Group Technology to produce a full drawings of the mold more effectively Most of the entity data should be extracted from the assembly drawing by pattern matching technique. An automated design system is developed using the extracted data of entities and thus shows a good interfaces between the design stage and producing part explosion without any manual conversion procedure under the AutoCAD environment.

• Design & Manufacturing
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• 제16권4호
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• pp.67-74
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• 2022

Injection molding is a cyclic process comprising of cooling phase as the largest part of this cycle. Providing efficient cooling in lesser cycle times is of significant importance in the molding industry. Recently, lots of researches have been done for rapid cooling of a hot-spot area using CO2 in injection molding. The CO2 flows under high pressure through small, flexible capillary tubes to the point of use, where it expands to create a snow and gas mixture at a temperature of -79℃. The gaseous CO2 removes heat from the mold and releases it into the atmosphere. In this paper, a CO2 cooling module was applied to an injection mold in order to cool a large area cavity uniformly and quickly, and the cooling performance of the injection mold was investigated. The product was a high-curvature molded part with a molding area of 300x100mm. Heat cartridges were installed in a stationary mold, and CO2 cooling module was inserted inside a movable mold. Through structural analysis, it was confirmed that the maximum deformation of mold with CO2 cooling module was 0.09mm. A CO2 feed system with a heat exchanger was used for cooling experiments. The CO2 was injected into the holes on both sides of the supply pipe of the cooling module and discharged through hexagon blocks to cool the mold. It took 5.8 seconds to cool the mold from an average temperature of 140℃ to 70℃. Through the experiment using CO2 cooling module, it was found that a cooling rate of up to 12.98℃/s and an average of 10.18℃/s could be achieved.

• 대한기계학회논문집A
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• 제21권9호
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• pp.1470-1479
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• 1997

In this study, the plastic fan with high efficiency and low noise was designed and the capacity of the wind and the wind pressure were analysed and verified by CAE. After designing the metallic mold using the metallic mold design data, and the the metallic mold design was reformed by analysing the process of the material stream and injection filling by CAE. Also the metallic mold cutting data were formed using the metallic mold design data. These cutting data was used to produce the fan electrode by a machining center and then this electrode were used to manufacture the metallic mold by cutting the fan cavity by an electrical spark machine. The purpose of this study is to find out the sub-optimal condition on the productivity and improvement in quality of the plastic fan by integrating a series of this process with a computer.

• Design & Manufacturing
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• 제2권3호
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• pp.40-44
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• 2008

Shaving in sheet metal forming is defined as a finish process to make the sheared surface clean which was blanked or pierced in the previous shearing stage. In this study the new shaving technique is applied to the progressive operation. The specimen is automatically fed by continuous movement of the strip. Which improve the positioning accuracy higher. For this study a square part which consist of blanking and piercing is selected for investigation and the progressive die which includes pre-piercing, pierce-shaving, half-blanking and blank-shaving etc is prepared for specimens of steel sheet(SPCC) and aluminum alloy sheet(AL5052). Experiments are carried out for several working variables such as shaving allowance, pre-shearing clearance and relative half-blanking depth. Consequently it was confirmed that the shaving by progressive die can be successfully employed to produce the clean parts requiring shaving process and optimum working conditions for shaving SPCC and AL5052 sheet metal are shaving allowance of 0.2mm(1.3% of thickness) and pre-shearing clearance of 5%.

• Design & Manufacturing
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• 제8권1호
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• pp.19-22
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• 2014

Today, looking at the trend of product development, interests of injection technology to reduce weldline are growing because of increases of polymer composite materials that containing functional elements and demand of no-painted injection in accordance with environmental regulations. In this paper, surface temperatures of mold increased using high temperature gas for elimination of weldline and characteristics of weldline are analyzed according to mold temperature($60^{\circ}C{\sim}120^{\circ}C$).