• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.168-171
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• 2009

High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a non-contact procedure. Though the induction heating has an advantage in terms of its rapid-heating capacity on the mold surface, it still has a restriction on mold temperature control due to geometric restriction of an induction coil according to the mold shape. It has been recently applied to the injection molding of thin-walled parts or micro/nano structures. For localized induction heating, an injection mold composed of ferromagnetic material and paramagnetic material is used. The electromagnetic induction concentrates on the ferromagnetic material, from which we can selectively heat for the local mold elements. The present study proposed a localized induction heating method by means of selective use of mold material. The feasibility of the proposed heating method is investigated through the comparison of experimental observations according to the mold material.

• Design & Manufacturing
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• v.9 no.1
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• pp.5-8
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• 2015

The company Daewoo Precision Industries imported fine blanking press of 40 tons from Switzerland with fine blanking tool in order to produce the fuse part of bomb in 1978 at first in Korea. About 1985 the first fine blanking tool for producing the door lock parts was manufactured in the company Gold Star (now LG). And then this technology was grown up with the growth of automobile industries in Korea. Now 31 companies are closely related to the fine blanking technology and there are total 146 fine blanking presses in Korea. The developments of fine blanking technology in industries have been oriented to the production of precise fine blanking parts, the reduction of die roll height on fine blanking parts, the production of complex fine blanking parts with progressive fine blanking tool including forming and forging technology, the production of high-strength steel fine blanking parts and so on. Some R&D activities in KITECH were introduced.

• Journal of the Korean institute of surface engineering
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• v.35 no.3
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• pp.113-120
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• 2002

Injection molded plastic parts have many surface defects. These include a weld line, sink mark, flow mark, gloss, shading, scratching etc. Because these surface faults are not aesthetically acceptable, plastic parts are produced through painting or texturing. The purpose of this paper is to develop paintless molded parts using a flow control method. Computer aided injection mold filling simulations were used in order to minimize the number of defects from injection molding. Based on the numerical results, FR(Flame Retardant) HIPS was developed and the guidelines for part design, mold design, and the processing conditions were established. The effects of cost savings, improvements in productivity, and recycling were considered by reducing the number of surface faults and eliminating the painting process.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2396-2403
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• 1994

An experimental study on material characterization and mechanical properties of SMC(Sheet Molding Compounds) compression method parts was carried out. Simple compression test using grease oil as a lubricant was carried out to characterize flow stress of SMC at elevated temperatures. Two different mold temperatures, $130^{\circ}C{\;}and{\;}150^{\circ}C$ and two different mold speeds, 15, 45 mm/min were used for preparing the specimen of SMC compression molded parts. Surface roughness, tensile, and 3-point bending tests were used to determine the effects of molding temperatures and speeds on mechanical properties of compression molded SMC parts. Orientation and distribution of glass fiber in the compression molded SMC parts were also investigated by photographing the burnt flat specimen and taking SEM(Scanning Electron Microscope) of cross-sectional T-specimen.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1933-1947
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• 1991

The synthesis of supplementary features of injection molded parts has been done empirically, since it requires profound knowledge about the features' moldability and causal effects on the properties of the part, which are not available to designers through current CAD systems. RIBBER is a knowledge module which contains knowledge to permit non-experts as well as mold design experts to generate acceptable supplementary features of injection molded parts. A knowledge-based CAD system is constructed by adding the knowledge module, RIBBER, for mold feature synthesis and appropriate CAE programs for mold design analysis to an existing geometric modeler in order to provide designers, at the initial design stage, with comprehensive process knowledge-based CAD system is a new tool which enables the concurrent design and CIM with integrated and balanced design decisions at the initial design stage of injection molding.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.210-221
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• 2000

Plastic mold designers and frequently faced with optimizing multi-quality issues in injection molded parts. These issues are usually in conflict with each other and thus tradeoff needs to be made to reach a final compromised solution. in this study an automated injection molding design methodology has been developed to optimize multi-quality characteristics of injection molded parts. The features of the proposed methodology are as follows : first utility theory is applied to transform the original multi-objective problem into single-objective problem. Second is an implementation of a direct search-based injection molding optimization procedure with automated consideration of robustness against process variation. The modified complex method is used as a general optimization tool in this study. The developed methodology was applied to an actual mold design and the results showed that the methodology was useful through the CAE simulation using a commercial injection molding software package. Applied to production this study will be of immense value to companies in reducing the product development time and enhancing the product quality.

• IE interfaces
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• v.9 no.1
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• pp.13-24
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• 1996

Quality of injection molded parts is dependent on both mold design and processing conditions. From the mold design point of view, an optimal shrinkage should be used to compensate the shrinkage of molded parts. From the processing point of view, it is important to analyze the priority of processing conditions because a number processing conditions affect the quality of molded parts. Processing analysis employing the design of experiment was performed, and the shrinkage of molded part was considered as a characteristic parameter to improve the quality. As the result of the analysis of variance on SN ratio of a characteristic value, injection speed and bolding pressure were selected as two effective process parameters. Regression analysis on shrinkage and processing conditions was carried out, and an optimal processing condition was obtained by the response surface analysis. Shrinkage at the optimal condition could be used to reduce the number of try-cut at the step of mold making. The ranges of indirect control parameter, such as maximum cavity pressure or weight, measured at the optimal processing condition were used for monitoring the quality of molded parts in process.

• The Journal of Society for e-Business Studies
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• v.8 no.3
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• pp.37-52
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• 2003

ISO 13584 Parts Library (PLIB) standard is making its way into e-business as a norm for classifying products and their characteristics. PLIB is a multi-parts standard, and the Part 42: Methodology for structuring Parts families Provides the information model and design Principles for the data dictionary of parts library or e-catalog. If e-catalog systems are built using a data dictionary that is constructed based on PLIB dictionary data model, many different e-catalog systems can be easily integrated and interoperated. This paper studies the roles and requirements of the data dictionary in e-catalog, and applies the data model and design principles of PLIB Part 42 to construct a data dictionary from the viewpoint of ontology Based on the analysis results, we propose a data dictionary of die and mold parts, and implementat the B2B e-catalog system.

• IE interfaces
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• v.12 no.3
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• pp.480-486
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• 1999

Mold base design is one of the most critical steps in production of plastic parts. This paper presents an efficient method for generating a 3D CAD library for injection mold base and mold components. In this paper, a new description language (DL)formats are proposed. These DL formats can represent the geometric feature, the variable dimensions and the assembly structures of mold base and its components. And the processes of adding the mold components and creating the mold assemblies can be performed very easily and efficiently by using DL scripts. Proposed method has been tested by implementation of 3D library with DL scripts and DL-interpreter with C language. The DL and interpreter are independent of CAD system. They were applied to the automatic mold base designing system which works on Unigraphics V15. The system is developed with UG API function under Windows-NT environment.

• Transactions of Materials Processing
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• v.6 no.6
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• pp.489-499
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• 1997

The injection molding process is analyzed to get the information on the mold design parameters and the optimum process conditions for automotive plastic front fender. The gate position, runner size and cooling channel are determined by the estimation of the flow balance, packing time, uniform cooling and shrinkage and warpage in the injection molding analyses. The procedure can be used in the mold design in the early stage when developing plastic parts.