• 소성∙가공
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• 제15권8호
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• pp.628-632
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• 2006

The gate mark in injection molded part is a kind of surface defects. The formation of gate mark has been investigated in this study. SEM photographs and surface roughness have been examined to study gate mark. The specimens were molded for various injection conditions, such as injection temperature, mold temperature, and injection speed. Gate diameter and mold surface condition were also molding variables. Gate marks were reduced as injection speed and mold temperature increased. Gate diameter and injection temperature did not affect the gate marks. No etching of mold surface showed no gate marks for any molding conditions.

• 소성∙가공
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• 제16권1호
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• pp.36-41
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• 2007

Thermoplastic elastomer(TPE) can be recycled and molded such as commercial thermoplastic. Therefore TPE has being widely applied on automobile, household and etc. in these days. This study shows the variation of mechanical properties and shrinkage on TPE moldings for variation of injection molding conditions such as injection pressure, holding pressure, melt temperature, mold temperature and etc. Mechanical properties in relation to tensile strength, hardness and shrinkage in connection with precision dimension of part are investigated. The tensile strength and shrinkage of the experimental TPEs are mainly influenced by injection pressure and melt temperature. All injection molding conditions scarcely affect on hardness. To verify the variation of tensile strength and shrinkage, morphology of TPE molding was scanned by the SEM. The morphology showed that as the melt temperature increased, the rubber particles on the TPE became smaller and widely were dispersed. This behavior of rubber particles influenced on the increase of tensile strength.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.265-268
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• 2005

Thermoplastic elastormer (TPE) has many advantages such as high flexibility, high elasticity and high elongation, etc. TPE is easily molded such as plastic materials, therefore, many TPE parts are applied as home appliances and mechanical parts. However, if TPE is once molded, its mechanical properties are changed by injection molding conditions such as melt temperature, mold temperature, injection pressure and holding pressure, etc. In this study, the influences of the injection molding condition on the mechanical properties of thermoplastic vulcanizates(TPVs), which is one of the TPE, were investigated. By the injection molding experiment, as increasing the melt temperature, the tensile strength, shrinkage and hardness decreased. By the scanning electron microscope (SEM) analyzing the TPVs' crystallization, the morphology was affected by the melt temperature.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.45-46
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• 2006

In recent years, micro powder injection molding $(\mu-PIM)$ is being explored as an economical fabrication method for microcomponents in microsystems technology (MST). Technical and economic comparison was performed for $\mu-PIM$ processes. Molding experiment and simulation during the filling process were performed to evaluate several different geometries and processing conditions. The influence of material parameters and process conditions on mold filling were examined as a function of features size using microchannels as an example. It was found that the heat conductivity and viscosity of feedstock, geometry and mold temperature were the most critical parameters for complete filling of micro features.

• 한국기계가공학회지
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• 제20권8호
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• pp.60-66
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• 2021

This study aimed at identifying and optimizing the heating-condition parameters that cause surface defects during the compression molding of chalcogenide glass (GeSbSe) lenses through thermal analysis. We derived the optimal heating conditions for molding chalcogenide glass lenses through thermal analysis and analyzed the surface defects. As a result, we observed a significant reduction in surface defects, which verified the analysis process.

• 한국분말재료학회지
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• 제22권1호
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• pp.1-5
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• 2015

Powder injection molding is an important manufacturing technology to mass produce superalloy components with complex shape. Injection molding step is particularly important for realizing a desired shape, which requires much time and efforts finding the optimum process condition. Therefore computer aided engineering can be very useful to find proper injection molding conditions. In this study, we have conducted a finite element method based simulation for the spiral mold test of superalloy feedstock and compared the results with experimental ones. Sensitivity analysis with both of simulation and experiment reveals that the melt temperature of superalloy feedstock is the most important factor for the full filling of mold cavity. The FEM based simulation matches well the experimental results. This study contributes to the optimization of superalloy powder injection molding process.

• 산업공학
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• 제15권3호
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• pp.263-269
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• 2002

The injection molding process is a one of the most efficient techniques for manufacturing plastic parts of complex shape at low cost. In injection molding, molten plastic material is injected into the mold and cooled. Selection of molding conditions greatly affects the quality of molded parts. In this case study, we attempted to optimize the injection molding condition for a cooling filter using Taguchi experimental design methodology. The injection molding experiments were carried out using the Moldflow simulation software.

• 한국기계가공학회지
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• 제12권5호
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• pp.94-101
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• 2013

Injection molding process is one of the most important methods to produce plastic parts with high efficiency and low cost. The objective of this study is to implement the best plastic injection molding process for LED TV speaker frame. Moldflow analysis and simulation of plastic injection molding process were carried out in order to predict optimal modeling operation conditions and then injection molded part was produced various type of resin temperature, filling time and injection pressure variation. the result was that the best injection molding condition is set as 60bar pressure, 2sec filling time and $310^{\circ}C$ degree. The study result would be useful to variety of plastic injection molding process.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1107-1112
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• 2008

The objective of this paper is to investigate into the influence of the injection conditions on the insert deformation and the wall thickness of the injection part using the three-dimensional injection molding analysis. Full three-dimensional insert model was added to the injection molding analysis model to consider the effects of insert deformation during the injection molding process. In order to obtain the optimum injection molding condition with a minimum insert deformation, degree of experiments were utilized. From the results of the analyses, it was shown that the optimum injection condition is injection time of 1.6 sec, injection pressure of 30 MPa and packing time of 15 sec. In addition it was shown that the wall thickness is approached to target thickness when the core deformation is considered in the injection molding analysis.

• Design & Manufacturing
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• 제2권1호
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• pp.39-43
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• 2008

There occur not only many problems in the injection process but also low quality productivity due to the injection conditions of various injection factors. Injection molding process factors such as molding temperature, injection pressure, flow rate and flow velocity, must be controlled properly in filling and packing phases in the injection molding process. In this study, effects of these factors on the injection molding were investigated through the flow analysis for the holding pressure affecting cooling time. Results of this study would be helpful to setting of holding pressure for optimization of forming condition in order to reduce cooling time in injection molding.