• Journal of computational fluids engineering
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• v.17 no.2
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• pp.53-57
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• 2012

Design of the cooling channels of a plastic injection mold affects the quality and the productivity of the injection processes. In the injection process, the melted resin with high temperature enters the mold cavity, and just after the cavity is filled the heat should be dissipated through the cooling channels simultaneously. The purpose of this study is to analyse the heat transfer phenomenon and to estimate the temperature distribution in the mold to evaluate the cooling effect of the channels. The injection mold is assumed to have cooling channels of circular cross section and each channel has the same coolant flow rate. and The cavity has a rectangular shape. The results show that as the cooling channels get closer to the cavity surface, the cooling efficiency increases as might easily be guessed. However, due to the final hot resin flow from the gate an intensive cooling is required in that region.

• Design & Manufacturing
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• v.15 no.4
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• pp.8-13
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• 2021

A plastic roller for opening and closing the safety door of the injection molding machine was molded. The dimensional change of the measurement position of the roller was studied when the cooling time was applied differently among the molding conditions, and when the temperature of the coolant applied for mold cooling was also applied differently. Cooling times of 300 seconds and 400 seconds, hot and low-temperature coolant were applied. When the low-temperature coolant was applied, the measuring point of the roller shrank by 0.03 mm. However, when the high-temperature coolant was applied, the measuring point shrank by 0.3 mm. It was found that the application of low-temperature coolant among coolants was more suitable for the reference dimension of the molded article compared to the application of high-temperature coolant. Among the cooling water applied for the molding of plastic rollers, when high-temperature coolant is applied, the shrinkage rate measured immediately after ejection was smaller than when low-temperature coolant is applied. However, it was found that post shrinkage, which occurs over time, occurs much larger when high-temperature coolant is applied.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.397-402
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• 2000

In this paper, we have been concerned with development of plastic mold design system by using Auto CAD. We provides a interface and interaction for mold designer who can select optimal mold base and mold parts within Auto CAD environment. We use the paramatric design method and an essential elements group forms. This program made for using Visual Lisp, DCL and Visual Basic that could easily get a database which is built to mold base and parts within Auto CAD. We provide 6 types mold base and 35 parts database for designer. In addition, it will be lined to mold cost and not only 2-D but also 3-D models

• Design & Manufacturing
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• v.9 no.3
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• pp.9-13
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• 2015

Plastic material has been applied to many automobile parts with the automotive lightweighting trend. In this study, a passenger air bag(PAB) housing which is produced by steel material in the present were molded using a plastics material. Before design and making of a mold for the PAB housing molding, it was carried out injection molding analysis. By analyzing the deformation results, the correction dimension for mold designing was determined. The design and manufacturing the mold applied the correction dimension were conducted. It was performed actual injection molding. The warpage value of the PAB housing was similar to the warpage of the injection molding analysis.

• Design & Manufacturing
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• v.13 no.1
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• pp.25-30
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• 2019

This paper presents the design strategy for the optimal RTM molds of Carbon Fiber Reinforced Plastic (CFRP) by carbon fiber draping and resin flow simulation. First, the mold shape and molding condition were determined considering the undercut and die face of the product in the draping simulation, which made the preliminary shape of the product by compressing the carbon fiber. After that, the diffusion behavior during the injection of resin in the mold was predicted by the resin flow simulation. Finally, the optimal mold shape was designed by selecting the locations of resin injection port and vent based on total results of simulations. In this paper, the mold of automotive side mirror case was selected as the representative product. Also, the actual mold was manufactured based on the simulation design to confirm the practicality of it. This study is expected to contribute to the industry as a technology to improve the reliability and productivity of CFRP producted by RTM process.

• Transactions of Materials Processing
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• v.11 no.8
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• pp.691-700
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• 2002

Injection molded plastic parts have many surface detects: weld line, sink mark, flow mark, gloss, shading, scratching, and so on. Because these surface faults have not been accepted esthetically, plastic parts are Produced through painting or texturing. The purpose of this paper is to develop a paintless molded part of TV Mask Front by flow control method and gas-assisted injection molding. In order to minimize defects from injection molding, this study was carried out using computer aided injection mold filling simulations using MF/FLOW and MF/GAS. Based on these numerical results, we developed FR(Flame Retardant) HIPS and established guidelines of part design, mold design, and Processing conditions. We have achieved of cost sayings, improvement of productivity, and utilization of recycling by eliminating surface defects and painting process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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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.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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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.

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.175-181
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• 2008

The technologies of mold design, manufacturing, injection molding process and computer aided engineering(CAE) are developed rapidly with the growth of plastic product market. Injection molding process optimum design can not be easily determined. This study was determined factors and levels which carried out to analyze an influence of narrow pitch BGA socket warpage and performed investigating the main effect and interaction effect between factors using design of experiment. The result of this paper is injection time and packing pressure are affect on narrow pitch BGA socket warpage at injection molding.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.201-206
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• 2003

Plastic injection mould have two kinds of trouble, one is in mould another in injection parts. Most of defects of the former take the cause in a design like in structure and working, the later weld line, transforming, sink mark, burning, flow mark, scratching, shading, black hole and so on. Most of problems of the later is difficult for making a clear definitely the reason of defects because of complexible. The purpose of this paper is to improve the quality of plastic injection mould and parts with inquiring the counter plan and rouble of the part of Flat TV Front Cover by flow control method and gas- assisted injection moulding. For minimizing defects from injection moulding parts, this paper was investigated with using computer aided injection mold filling simulations. Based on these numerical results, I established guidelines mould design and injection processing condition. As a results I got the improve of quality, minimizing surface defects moulded parts and troubles in mould.