• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1483-1486
• /
• 2003

Injection mold is a manufacturing process used to produce the various parts of complicated shape at a low cost. Many factors such as, section shape, resin and mold temperature, filling time, etc, affect on the quality of injection part during injection molding process. The precent study, was carried out the shrinkage analysis of shoes injection mold to optimize runner shape based on filling and packing pressure with MoldFlow. Taguchi design and analysis of variance are used to optimize injection mold design.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.21-22
• /
• 2023

In order to manufacture high-quality free-form concrete panel (FCP), it is necessary to analyze the limitations of free-form silicone mold (FSM) and conduct technology development research. Currently, the FSM used in FCP manufacture is classified into a side silicon mold(SSM) and a lower silicon mold(LSM). In this study, the limitations of each silicon mold were analyzed and solutions were proposed. In the case of side silicon mold, there is a limit to cannot supporting the side pressure of concrete. Therefore, a mold stacking method was proposed, and at the same time, a process of correcting the movement value of the rod was proposed. In the case of the lower silicon mold, there is a limit to completely implementing the design shape. Therefore, a real-time scanning method and a process of displaying FCP shape coordinates were proposed. The results of this study are expected to be used as basic data for manufacturing high-quality FCP.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.181-182
• /
• 2015

The production technologies of free-form concrete panels are emerging to satisfy the need of modern complex shaped in architectural design. This study aims for introducing and improvising the innovative technique called Rod type mold that overcomes the difficulties in some extent by enabling the mold to be used many times, making the shape of the mold adjustable in a flexible way and describing its production process to provide the alternative solution for the construction of free-form mold with considering the features including reusability and optimization cost across its production process. In this study, the freeform concrete panel shape was designed and experiment was done using computerized numeric control machine and rod type mold. The problems appeared on achieving desired shape while operating on rod type mold. The process of identifying all the root causes and contributing causes that may have generated an undesirable condition were done. Consequently, the conical or semicircular shaped was proposed for the end of Numerical control rod and replaced it with the existing flat shaped end to avoid the detachable problem and to improve rod type mold performance.

• Elastomers and Composites
• /
• v.49 no.3
• /
• pp.220-224
• /
• 2014

The tire tread is contacted with road surface directly. It gives significant effect on the breaking conditions, traction, noise and so on. The tread having grooves with complex geometry is molded by shaping process. The flow behavior of tread rubber in a mold affects the quality of the tread and it leads to the running performance of automobile. In this study, the flow behavior of rubber in shaping process has been investigated by computer simulation. The objective of flow simulation is the design of tread shape based on the contact of rubber on the mold surface and flow behavior of rubber. Different sequences of contact of rubber on the mold surface and flow behavior of rubber are observed according to the shape of tread on the mold surface. It was verified that the shape of tread gives significant effect on the flow behavior of rubber. Different flow behaviors of rubber and sequential contact of rubber to the mold surface were observed according to the shape of tread on the mold surface. Therefore, we have identified that the shape of tread give a change in the flow behavior of rubber.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.199-200
• /
• 2006

It will not be an exaggeration to say that one of the most important features of RT (Rapid Tooling) technology is to easy manufacturing complex shape of cooling channel in injection mold. That is, RT technology is hardly influenced complex shape of tool, Therefore, mold designer can optimize the position and shape of cooling channel whatever they want. In this study, we optimized cooling channel through CAE analysis to solve the problem; prototype-connector-mold applied conventional cooling channel, locally warped by internal stress: The effect of three-dimensional cooling channel was supported by simulation result. But it is impossible to produce injection mold applied three-dimensional cooling channel through machining operation. Therefore, we produced the prototype-connector-mold with three-dimensional cooling channel using Direct Metal Laser Sintering (DMLS) process, and get good-quality prototype-connector without warpage.

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

• Design & Manufacturing
• /
• v.15 no.4
• /
• pp.1-7
• /
• 2021

A study on in-mold punching technology for hole piercing during molding of hollow plastic parts was conducted. Considering the non-linearity of the HDPE plastic material, mechanical properties were obtained according to the change in temperature and load speed. A standard specimen for the in-mold punching test was designed to implement the in-mold punching process, and the specimen was obtained through injection molding. In order to analyze the influence of process variables during in-mold punching, an in-mold punching mold capable of controlling variables such as temperature and support pressure of the specimen was designed and manufactured. Mold heating characteristics were confirmed through finite element analysis, and punching simulations for changes in process conditions were performed to analyze punching characteristics and reflected in the experiment. Through simulations and experiments, it was found that the heating temperature, punch shape, punching speed, and pressure of the back side of the specimen were very important during in-mold punching of HDPE materials, and optimal conditions were acquired within a given range.

• Fashion & Textile Research Journal
• /
• v.24 no.4
• /
• pp.443-450
• /
• 2022

This study developed a three-dimensional helmet mold design software that can design helmets for treating the infant plagiocephaly (flat head syndrome) using three-dimensional head scan data. For this, the three-dimensional head data of sixth SizeKorea body measurement project as well as the data produced by a head modeling software were used to prepare the head shape data of plagiocephaly patients. A total of 14 landmarks and 10 dimensions of heads required for helmet mold shape design and plagiocephaly diagnosis were automatically measured using an anthropometric analysis software. Using the software developed in this study, plagiocephaly can be diagnosed not only visually by three-dimensional head data visualization but also quantitatively by calculating the medically defined indices such as cranial index, which measures the proportions of the head, and the cranial vault asymmetry index, which measures the asymmetry of the head. The basic shape of the helmet mold was automatically generated based on the head scan data. Additionally, it is possible to fine tune the shape of the mold to reflect individual characteristics by using a free form deformation technique. Finally, the designed helmet mold was converted into the data that can be printed on a three-dimensional printer for generating the actual prototype.

• Design & Manufacturing
• /
• v.10 no.3
• /
• pp.25-29
• /
• 2016

Recently, a hyaluronic acid micro needle patch for therapeutic and cosmetic purposes has been used by attaching directly to the skin with a pattern having a micro needle shape of 1/3 thickness of hair. These products are attracting attention as an innovative product that maximizes the effect by activating the active ingredient in the skin in the deep skin without blocking the horny layer because the micro needle shape exists on the patch surface so that it can penetrate effectively to the skin. Currently, DAB (droplet air blowing) or MEMS technology is used to make pattern shapes for patches. Because of this technology, manufacturing time is long and manufacturing cost is high, so we tried to develop the mold technology to machine the microneedle shape directly to the metal. In this study, we first fabricated a needle pattern with a quadrangular pyramid shape and finally produced a conical needle pattern.

• Journal of Korea Foundry Society
• /
• v.26 no.2
• /
• pp.98-103
• /
• 2006

Metal-mold reactions between investment mold and TiAl alloys were investigated for the economic net-shape forming of TiAl alloys. The effect of mold preheating temperatures on the metal-mold reaction were investigated using a vacuum induction-melting furnace. In the case of TiAl alloys, there were no ${\alpha}$-case formation reactions. There were neither interstitial nor substitutional ${\alpha}$-case formations as TiAl alloys have both negligible solubility of oxygen and low activity in molten states. The fluidity of TiAl alloys increases with mold preheating temperature since they have a peritectic reaction that appears in the form of envelope, surrounding each particles of the primary constituent. The results of the investment casting of TiAl alloys confirm that the casting route in our study can be an effective approach for the economic net-shape forming of TiAl alloys.