• 한국정밀공학회지
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• 제9권4호
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• pp.109-117
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• 1992

Mixing of ceramic-binder system was investigated experimentally and theoretically for application to Ceramic Injection Molding. Polypropylene, stearic acid, and paraffin wax were selected as the binder system, and silicon nitride fine powders were selected as the ceramic material. Single screw ectruder was employed as the mixing equipment. Theoretical analysis was performed to investigate the mixedness of mixture quantitatively. The analysis predicted average residence time average total strain, and average shear stress as a function of screw speed for mixtures of different volume fraction. Qualitative mixedness of mixture and characteristics of mixing were investigated by using SEM and EPMA. In addition, rheological properties of the mixture were investigated by using a capillary rheometer to examine possibility of injection molding.

• 한국정밀공학회지
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• 제16권8호
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• pp.71-78
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• 1999

The application range of injection molded parts is expanding by the development of engineering plastics with good mechanical properties. Plastic gears are specially used as automotive parts due to an excellent performance in the characteristics of a strength vs. weight, and the study of injection molding process of plastic gear using Nylon66 is performed in this study. Filling, packing and cooling analyses were done by using the simulation software like Moldflow, and a mold was designed by following the simulation results. Pin-point gates with three points were taken to satisfy the design guides like a full-shot, and lower clamping force and uniform shrinkage. Characteristics of shrinkage of molded gear and temperature difference between cavity and core sides of a mold were shown.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.341-347
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• 2003

Single flighted screw extrusion is the most cost effective method for the production of film, sheet, pipe and the fundamental step in other processes including blow molding and injection molding The temperature and injection pressure in barrel play a very important role in quality of products. Because thermal distortion and displacement of barrel by temperature difference and injection pressure difference cause irregular resine melting and flow. In this paper thermal distortion and stress of barrel includes pressure and temperature distributions by finite element analysis to understand dynamic characteristics of barrel.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.316-319
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• 2002

Injection mold is a manufacturing process used to produce parts of complicated shape at a low cost. Many factors affect the quality of injection molded part during injection molding process. A study on the optimization of injection mold is progressed by using a simulation software like Moldflow. Filling, packing and cooling phases of injection molding processes are analyzed according to the mold design considering the shrinkage of molded part, the degree of filling rate and the wearing of a mold. Taguchi method is applied to analyze the significance of processing parameters and the dynamic characteristics according to the variation of processing parameters. From the results, the mold temperature and packing pressure influenced strongly the shrinkage of injection molded part.

• 대한기계학회논문집
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• 제18권11호
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• pp.3084-3090
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• 1994

A new flow model is developed for the analysis of compression molding of sheet molding compounds(SMC) and penalty finite element formulation is presented to predict flow front progressions more accurately. In this model SMC is assumed nonisothermal fluid, which has different viscosities in extension and in shear. The flow is allowed to slip at the mold and is resisted by friction force which is proportional to the relative velocity at mold surface. For the verification of the model, the press force and flow patterns are compared with those of experiments and available results by other works in this field. It is also demonstrated, using the computational procedure described and the proposed model, that optimal initial charge shapes for the filling can be effectively computed.

• 소성∙가공
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• 제11권7호
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• pp.581-588
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• 2002

Among the processes to produce micro lens, the process using press molding is a new technology to simplify the process, but it contains many unknown variables. The press-molding process proposed in this paper was simplified into two step process, the first step is the pressing to design the preform for glass element, the second step is the annealing to reduce the residual stress. It is important to estimate the amount of shrinkage of glass gob and the residual stress during process. It Is difficult to evaluate the process variables as mentioned above through the experiment. The influences due to process variables was evaluated by using FEM parametric analysis. The results in this paper can be applicable to produce micro lens.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1494-1499
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• 2008

플라스틱은 양호한 내구성과 더불어 가벼우면서 장시간 경과하여도 변질이 없는 특성으로 인하여 자동차 내장 부품의 가장 주요한 소재로 활용되어지고 있다. Moldflow를 이용한 자동차 기어박스커버의 플라스틱 사출공정 시뮬레이션을 통해 충전시간, 웰드라인, 에어트랩 등 사출성형 공정에 대한 사전분석을 제시하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 금형가공,미세가공,플라스틱가공 공동 심포지엄
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• pp.126-131
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• 2005

In the present study, warpage characteristics of mobile phone cover through injection molding process were investigated by using design of experiments. Warpage in plastic injection molding process has a significant effect on quality of product. Effects of injection time, packing pressure, packing time, mold temperature ana melt temperature on warpage of mobile phone cover were considered by CAE analysis and experiment with Taguchi method. The degree of warpage for the injection molded product was measured by using three dimensional CMM. It was shown that temperature parameter has more significant effect on the warpage of mobile phone cover than pressure parameter.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.99-102
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• 2009

The recent LCD TV market has made efforts to produce thinner, brighter, and clearer products, and experienced the rapid light source replacement from a line source of light CCFL to a point source of light LED. In particular, LGP(Light Guiding Panel) among key parts composing BLU(Back Light Unit) has limits of the injection molding technology as well as the mold design, its processing and manufacturing technology so that it is hard to produce large LGP over 40 inch. To produce large light-guide panels over 40 inch under the injection molding process, a mold 3D model was developed in the design process before manufacturing a mold and structure unification was processed through CAE analysis. As a result, it was possible to construct the mold design process, and it is expected to manufacture the optimized mold by applying the mold design and manufacturing process of large-scale rapid injection-compression molding that will be produced in the future.

• 대한기계학회논문집
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• 제15권1호
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• pp.163-168
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• 1991

본 연구에서는 여러가지의 성형조건에서 미끄름을 지배하는 상수를 측정하고, 유동 선단(flow front)에 미치는 이 상수의 영향을 검토한다. 또 측정된 상수를 가 지고 사각형 및 중공 원형 평판 압축성형에 대해서 2차원 유한 요소해석을 하고 실험 결과와 비교 검토한다.