• Proceedings of the Korean Fiber Society Conference
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• 1996.10a
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• pp.389-395
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• 1996

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.90-97
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• 2015

Optimization of multi-quality characteristics in injection molded parts is very important, but it is sometimes difficult for part/mold designers. The objective of this study is to develop a practical design methodology for optimizing two-quality characteristics of injection molded parts. To attain this end, we developed a new design-range reduction algorithm based on Taguchi's orthogonal arrays for two characteristics. Then, the algorithm was integrated with commercial injection-molding simulation tools. A feature of the proposed methodology is that it allows field-designers unfamiliar with general optimization methods to be able to apply the methodology to their design problems with ease. Finally, we have applied the proposed design methodology to optimization of weldlines and deflections in an actual bezel model. The results show the usefulness of this methodology.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.6 s.249
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• pp.615-621
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• 2006

Increased application of optical disks requires more improved dynamic stability of rotating disks. In this study, a new concept of controlling the processing conditions of injection molded disks was developed to improve vibration characteristics. The critical speed, which shows stiffness and dynamic stability of disk, is affected by the residual stress distribution; this varies as functions of distance from the gate and processing condition. The critical speed of disk was calculated with the initial stress taken into consideration, which was determined from injection molding simulation. Choosing melt temperature, mold temperature, filling speed and packing pressure as design parameters, critical speed is maximized with the method of response surface. It is shown that the stability of injection molded disk has been improved for the new condition obtained as a result of the study proposed.

• Transactions of Materials Processing
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• v.24 no.6
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• pp.418-425
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• 2015

Based on eco-friendly advantages and the enhanced development in the chemical and physical characteristics, liquid silicone rubber (LSR) is widely used in producing precision parts in the automotive, medical, electronics, aeronautical and many other industries. In the current work, a thermoplastic-thermoset multi component injection molding (MCM) was developed for a waterproof automotive connector housing using PBT and LSR resins. Measurements of the rheological characteristics of PBT and LSR were made to improve the reliability of the numerical analysis for the multi component injection process. With the measured viscosity, pvT and curing data, numerical analysis of the multi cycle injection molding was conducted using simulation software (Sigma V5.0).

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.149-153
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• 2008

The cavity of mold is exposed to high pressure during injection molding operation. Injection molded articles with deep depth are often demanded as design variety increases. Mold becomes weak and deformation increases as the mold depth increases. Thus the injection molds for deep depth articles should be designed to hold out high pressure or stress and large deformation. Through this study, equation for mold design was examined and suggested novel method to determine equation for mold design with deep depth. Novel equation developed in this study was consisted with cantilever and two points bending while previous equation was modified from just cantilever bending. The validity of novel equation was verified through computer simulation.

• Design & Manufacturing
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• v.11 no.1
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• pp.30-33
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• 2017

In this study, the mold technology for manufacturing of porous implant was investigated. Firstly, we considered the concept of insert molding technology with 3D printing of porous inert part. The part on implant was designed in the end region of the implant. And then main implant bodies were manufactured using conventional machining method. The other porous parts were designed and optimized with molding simulation. As the feature size of porous implant was so small that perfect feature of it using 3D printing technology could not be obtained. So, we proposed another scheme for manufacturing of the porous implant in the replace of the former approach. Polymer mold cores with 3D printing technology were considered. The effects of addictive manufacturing process parameters on the properties of mechanical and dimensional accuracy were investigated. Direct 3D printed polymer mold cores were designed and manufactured under the simulation of thermal and molding analysis. It was shown that 3D printed mold core with polymer could be adapted to the injection molding for porous implant.

• Korea-Australia Rheology Journal
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• v.12 no.2
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• pp.125-133
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• 2000

The present work is aimed at performing injection molding filling simulation of fiber suspension in polymer based matrix. The numerical simulation incorporates the coupling effect between the flow field and the fiber orientation state together with in-plane velocity gradient effect with recently proposed closure approximations. Predicted orientation components are compared with available experimental data of a film-gated strip and a center-gated disk. Predictions with IBOF closure approximation show excellent behaviors with regard to accuracy and numerical efficiency. However, predicted results seem to have consistent errors in comparison with experimental data. Diffusivity term which accounts for fiber-fiber interaction might have to be modified.

• Transactions of Materials Processing
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• v.19 no.3
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• pp.152-159
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• 2010

Rapid mold heating has been recent issue to enable the injection molding of thin-walled parts or micro/nano structures. High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a non-contact manner, and has been recently applied to the injection molding due to its capability of rapid heating and cooling of mold surface. The present study covers a three-dimensional finite element analysis to investigate heating efficiency and structural safety of the induction heating process of an injection mold. To simulate the induction heating process, an integrated simulation method is proposed by effectively connecting an electromagnetic field analysis, a transient heat transfer analysis and a thermal stress analysis. The estimated temperature changes are compared with experimental measurements for various types of induction coil, from which heating efficiency according to the coil shape is discussed. The resulting thermal stress distributions of the mold plate for various types of induction coils are also evaluated and discussed in terms of the structural safety.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.11
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• pp.1-8
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• 2019

In this study, we design the feed system and process conditions for a lamp garnish lens of an automobile. For this purpose, four design alternatives are presented and injection molding simulation analyses are performed. The optimal feed system is selected by considering the formability of the product and the cost of mold manufacture. The product formability is assessed by the weld line, warpage, sink mark and the maximum injection pressure, whereas the mold-making cost is estimated by the number of valve gates in the hot runner system. To improve the product formability, process conditions are optimized using an experimental design approach named one-factor-at-a-time. No weld line is generated as a result of the optimization. In addition, it is found the warpage and sink mark are reduced while the maximum injection pressure is increased, compared with those before the optimization.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.2
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• pp.7-16
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• 2014

Vehicle industry is developing research for producing high quality injection molded product. The main objective of this study is providing information about hydraulic system for researchers who are involved in the other fields, not hydraulic field. Another objective is developing hydraulic circuit simulation model which analyzes the cause of several destabilizing elements related to quality of injection molded products. Injection molded product consists of a lot of hydraulic parts, and there are many nonlinear facts for dynamic behavior. So, we used 'SimulationX' which is specialized in hydraulic system for developing simulation model.