• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.112-118
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• 1999

Shrinkage behavior was investigated to obtain more accurate dimensions of injected molding parts for free and restricted shrinkage conditions. various parameters for metal inserted injection process, such as thickness of resin, holding pressure and time, mo이 temperature and restriction condition of mold, were considered for the analysis of shrinkage phenomena. For numerical analysis, MOLDFLOW software was used to find the deterministic parameters of filling time, temperature, pressure and holding time. Also , experimental shrinkage effects were measured through actual injection molding process and the resin thickness was under controlled as 3 mm , 5 mm, and 7mm for the shapes of plastic gear made of Polymide(PA) and Polyxymethlene(POM). The main parameters of these injection processes were found to be holding pressure, holding time and mold temperature in the case of metal inserted molding.

• Design & Manufacturing
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• v.16 no.1
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• pp.62-69
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• 2022

In the present study, the injection molding optimization of a large thick LH type elastic frames for the reduction of warpage was performed. Two kinds of fine and coarse finite element models were prepared to investigate the efficiency of analysis time and quality on simulation results. In order to derive injection molding conditions that can minimize distortion of parts, it was investigated that the effects of mold temperature, resin temperature, injection time, hold pressure switching time, holding pressure and the hold time on deformation characteristics using the design of experiments. The main influential factors on the warpage were found from the optimization simulation and the geometry data of the warpage result was converted into an initial model for injection simulation. It was shown that a coarse model with good mesh quality could be adapted for mold design since the total analysis time using the proposed model was reduced to 1/10. The suggested inversed warpage model produced the best minimized result of warpage.

• Transactions of Materials Processing
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• v.14 no.6 s.78
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• pp.570-576
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• 2005

Powder Injection Molding(PIM) has recently been recognized as an advanced manufacturing technology for low-cost mass production of metal or ceramic parts of complicated geometry With this regards, design technology of dental scaler tip PIM mold, which has complex shape and small core pin (diameter=0.6mm), with the help of computer-aided analysis of powder injection molding process was developed. Computer-aided analysis for dental scaler tip mold was implemented by finite element method with non-Newtonian fluid, modified Cross model viscosity, PvT data of powder/binder mixture. Compter-aided analysis results, such as filling pattern, weldline formation, air vent position prediction were compared with experimental result, and eventually have been shown good agreement. The core pin (diameter=0.6mm) deflection analysis of dental scaler tip PIM mold during PIM filling process was also investigated before mold fabrication.

• Journal of Powder Materials
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• v.8 no.4
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• pp.245-252
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• 2001

Recent remarkable progress in the semiconductor industry has promoted smaller size of semiconductor chips and increased amounts of heat generation. So, the demand for a substrate material to meet both the characteristics of thermal expansion coefficient and heat radiation has been on the increase. Under such conditions, tungsten(W)-copper(Cu) has been proposed as materials to meet both of the above characteristics. In the present study, the W-10wt.%Cu powders were synthesised by the mixing and hydrogen reduction of the starting mixture materials such as W-Cu, $W-CuCl_2$and $WO_3-CuCl_2$ in order to obtain the full densification. The W-10wt.%Cu produced by hydrogen reduction showed the higher interparticle friction than the simple mixed W-10wt%Cu because of the W agglomerates. In the dilatometric analysis the W-10wt.%Cu prepared from the $W-CuCl_2$was largely shrank by heating up $1400^{\circ}C$ at the constant heating rate of $5^{\circ}C$/min. The possibility of application of metal injection molding (MIM) was also investigated for mass production of the complex shaped W-Cu parts in semiconductor devices. The relationship between the temperature of molding die and the pressure of injection molding was analyzed and the heating up stage of 120-$290^{\circ}C$ in the debinding process was controlled for the most suitable MIM condition.

• Transactions of Materials Processing
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• v.24 no.2
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• pp.121-129
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• 2015

A net-shape forming of small and complex-shaped metal parts by metal injection molding (MIM) has economic advantages in mass production, especially for STS 316L valve fitting. STS 316L offers excellent corrosion resistance, but it has poor machinability, which is a limitation in using it for a cost-effective production where both forging and machining are employed. Simulation and experimental analysis were performed to develop a MIM STS 316L 90° elbow fitting minimizing trial and error. A Taguchi method was used to determine which input parameter was the most sensitive to possible defects (e.g. sink mark depth) during the injection molding. The final prototype was successfully built. The results indicate that the simulation tool can be used during the design process to minimize trial and error, but the final adjustment of parameters based on field experience is essential.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1537-1538
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• 2013

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.269-274
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• 2001

This research covers the development of new technique for composite injection molding of high stiffness Sabot. An analysis of polymer resin is performed by means of making test specimen mold and doing test with accordance of ASTM test guidelines. Structural analysis and simulation of injection molding process are carried out in order not only to estimate but also to predict the characteristics of molding stresses what both product and structure of mold may have. For structural analysis software, Moldflow and LS-dyna are used and universal test machine is utilized for evaluating performance of sabot. Cases of adopting this material to sabot are not announced yet in domestic academic world. In addition to that, materials for polymer-metal mixed injection molding are imported on the whole due to deficient level of domestic technology. Therefore, this new developed injection molding technique using PEI material can make it available to ensure the technology of making mold, injection and design. Finally, this technique may be applicable to another sabot having different radius of warheads from now on.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.497-498
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• 2006

Powder Injection Molding (PIM) has recently been recognized as an advanced manufacturing technology for low-cost mass production of metal or ceramic parts of complicated geometry. With this regards, design technology of dental scaler tip PIM mold, which has complex shape, with the help of computer-aided analysis for powder injection molding process was developed. Compter aided analysis results, such as filling pattern, weldline formation, and air vent position prediction were investigated and eventually showed good agreements with experimental results.

• Design & Manufacturing
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• v.17 no.1
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• pp.27-32
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• 2023

In this paper, we intend to predict the mass of the spiral using CAE and machine learning. First, We generated 125 data for the experiment through a complete factor design of 3 factors and 5 levels. Next, the data were derived by performing a molding analysis through CAE, and the machine learning process was performed using a machine learning tool. To select the optimal model among the models learned using the learning data, accuracy was evaluated using RMSE. The evaluation results confirmed that the Support Vector Machine had a good predictive performance. To evaluate the predictive performance of the predictive model, We randomly generated 10 non-overlapping data within the existing injection molding condition level. We compared the CAE and support vector machine results by applying random data. As a result, good performance was confirmed with a MAPE value of 0.48%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1297-1298
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• 2010