• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2001년도 추계학술대회 논문집
• /
• pp.150-153
• /
• 2001

The present work concerns optimal design for the injection molding process of a deflection yoke (coil separator). The optimal design for the injection molding process is developed using design of experiments and finite element analysis. Two design of experiments approaches are applied such as: the design of experiment for mold design and the design the experiments for determination of process parameters. Finite element analyses have been carried out as a design of experiments for mold design: runner system and cooling channel. In order to determine optimal process experiments have been performed for various process conditions with the design of experiments scheduling.

• 대한기계학회논문집A
• /
• 제26권7호
• /
• pp.1348-1356
• /
• 2002

The present work concerns the optimal design for injection molding processes by using the design of experiments (DOE) and numerical analysis. The DOE approaches is planned to be able to consider two-way interaction, and have been applied progressively for both mold design and process design. Numerical analyses have been carried out as a design of experiments for mold parameters such as runner specifications and cooling channel configurations. In order to determine optimal process parameters, experiments have been performed for various process conditions with the DOE scheduling. As a result, the quality and productivity of the product have been improved, and the proposed approach can be successfully reflected on the industrial injection molding process of precision electronics parts.

• 대한기계학회논문집A
• /
• 제24권8호
• /
• pp.1968-1799
• /
• 2000

A warpage analysis program has been developed for fiber-reinforced injection molded parts. The warpage is predicted from the residual stress and anisotropic thermo-mechanical properties coupled with fiber orientation in the integrated injection molding simulation. A simple elastic model is used for the calculation of thermally and pressure-induced residual stresses which are employed as the initial conditions in the structural analysis. To improve the reliability of warpage analysis, a new triangular flat shell element superimposing well-known efficient plate bending and membrane element is presented. The numerical examples address the necessity to use anisotropic models for fiber-reinforced materials and show that predicted warpage is in good agreement with experimentally measured one.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집A
• /
• pp.745-750
• /
• 2000

A warpage analysis program has been developed for fiber-reinforced injection molded parts. The warpage is Predicted from the residual stress and anisotropic thermo-mechanical properties coupled with fiber orientation in the integrated injection molding simulation. A simple elastic model is used for the calculation of thermally and pressure-induced residual stresses which are employed as the initial conditions in the structural analysis. To improve the reliability of warpage analysis, a new triangular flat shell element superimposing well-known efficient plate bending and membrane element is presented. The numerical examples address the neccesity to use anisotropic models for fiber-reinforced materials and show that predicted warpage is in good agreement with experimentally measured one.

• 한국기계가공학회지
• /
• 제11권2호
• /
• pp.60-65
• /
• 2012

This paper deals with an CAE analysis and optimization of injection molding for a mobile phone cover. Two design goals are established in the optimization; one is to switch over the feed system from cold runner to hot runner for the purpose of reducing material costs, and the other is to minimize the warpage in order to improve product quality. By the full-factorial experiments for design parameters, we showed that the cold runner design could be changed to the hot runner design by replacing the current resin with a new resin of higher fluidity. In addition, we could significantly reduce the warpage of the cover product under the hot runner system by optimizing packing pressure and packing time.

• 한국정밀공학회지
• /
• 제16권8호
• /
• pp.71-78
• /
• 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.

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

• 한국기계가공학회지
• /
• 제13권4호
• /
• pp.21-27
• /
• 2014

The injection molding process has several advantages enabling it to produce large quantities of molded plastic products using a repetitive process. In recent years, it has been necessary to develop an injection molding process with micro/nano-sized patterns for application to the semiconductor industry and to the bio/nano manufacturing industry. In this study, we apply gas pressure to the inside of a mold and consider the gas dissolution phenomenon for a resin filling into a micro pattern with a line structure. Using numerical analysis, we calculate the filling ratio with respect to time for various internal gas pressures and various aspect ratios of the micro-patterns.

• 한국정밀공학회지
• /
• 제32권11호
• /
• pp.969-976
• /
• 2015

In the present study, a numerical investigation of an insert injection molding process was carried out for the development of thermoplastic microfluidic chip plates with metal electrodes. Insert injection molding technology enables efficient realization of a plastic-metal hybrid structure and various efforts have been undertaken to produce novel components in several application fields. The microfluidic chip with metal inserts was proposed as a representative example and its molding process was analyzed. The important characteristics of the filling stage, such as the effects of filling time and thickness of the part cavity, were characterized. Furthermore, the detailed distributions of pressure and temperature at the end of the filling stage were investigated, revealing the significance of metal insert temperature.

• 한국자동차공학회논문집
• /
• 제23권4호
• /
• pp.388-395
• /
• 2015

The waste gate valve (WGV) for gasoline vehicles operate in a harsh high-temperature environment. Hence, WGVs are typically made of Inconel 713C, which is a type of Ni-based superalloy. Recently, the metal injection molding (MIM) process has attracted considerable attention for parts used under high-temperature conditions. In this study, an MIM analysis for the head and other parts of the WGV is conducted using a commercial CAE program Moldflow. Further, optimal manufacturing conditions are determined by analyzing flow characteristics at various injection times and locations. Moreover, to improve the accuracy of the analysis results, we compare the actual temperature of the mold during injection processing with that observed through the analysis. As the results, metal injection patterns of analysis are well in accord with these of short shot test. And the temperature variations of analysis is also very similar with those of feedstock when metal injection molding.