• Resources Recycling
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• v.13 no.3
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• pp.43-49
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• 2004

In this study. an experimental work was performed to mold tensile specimens by using the injection molding machine. Melt temperature, mold temperature and the mixed ratio of recycled resin were selected as processing parameters for studying the effect of those conditions on the shrinkage and weight of molded parts. As a result, the shrinkage was increased with the higher mold and melt temperature and it was more sensitive to the change of mold temperature. On the other hand, the weight of molded parts was decreased with the increment of mold and melt temperature.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.484-489
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• 2011

Nowadays, the automobile manufactures make a great efforts to reduce manufacturing cost, body weight and to develop eco-environmental parts in order to be more competitive and solve global warming. For these reasons, materials of automobile's parts are changed over from general carbon steel and stainless steel to plastic and Aluminum. And, laser welding technology is introduced to apply welding between aluminum parts. In this paper, the data of laser welding parameters is collected through lots of the experiment according to the material, welding speed and laser power to apply laser welding in Aluminum fuel filler neck assembly. After manufacturing prototype of aluminum fuel filler neck, vibration durability test, tensile strength test and salt water test are applied to verify product's satisfied function.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.5
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• pp.660-666
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• 2010

In cellphone optical systems, a tiny difference of manufacturing has a strong influence on camera lenses. This study aims to find out the worst result by tolerances come from all parts in optical performance. First, 3D Measure Instrument, Roundness Measure Instrument, and Wavelength Measure Instrument were used for greater precision by making and measuring the parts to see how different from the drawings. It was confirmed that even narrow tolerances could result in defects by assembling. Tolerances in assembly should be concerned as those in parts through the research.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.431-436
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• 1986

The design and manufacture of injection molded polymeic parts with desired mechanical properties is a costly process dominated by empiricism, including the modification of actual tooling. This paper presents an interactive computer-based design system for injection molded plastic parts. This knowledge-based synthesis system provides a rational design strategy for injection molding and molded parts. It synergistically combines a rule-based expert system for hurestic knowledge with analytical process simulation programs. The theremomechanical properties of a molded part such as the effect of molecular orientation and weldline strength are predicted by the analysis programs; while the expert system interprets the analytical results from the process simulation, evaluates the design, and generates recommendations for optimal design alternatives. The heuristic knowledge of injection molding is formalized as production rules of the expert consultation system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.102-106
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• 1999

One of the main causes of unwanted dimensional changes in precision metal mold casting parts is excessive and irregular residual stresses induced by temperature gradients and plastic deformation in the solidifying shell. Residual stresses can also cause stress cracking and lower the fatigue life and fracture strength of the casting parts,. In the present study aluminum alloy casting system with metal mold equipped with electrical heating elements and water cooling units was designed and the casting specimens were produced to quantify the effects of different cooling conditions on the development of residual stresses. the layer removal method was used to measure the biaxial residual stresses in casting specimens produced from the experiments. The experimental results agreed with Tien-Richmond's theoretical model for thermal stress development for the solidifying metal plate

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.48-53
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• 2004

Injection molded plastic parts have many surface defcts: Warpage, wedline, flowmark, zetting, scratching, shading and so on. In the desktop mnitor's case, Weld line have been one of the main surface defects. Nowadays in the pursuit of light weight of parts, one of the big problems of LCD Monitor thinks Warpage and surface shrinkage. In this paper, we introduce some instances for prevevting these defestcs in the side of mould drawing, parts drawing and processing condition. Based on these, we tried to find out the optimum processing conditions through repeatedly tried injection moulding after reflecting these instances.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.423-426
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• 2005

The injection molding process has applied to a variety of fields by a development of various plastic resins. Recently, this process has been extending to a field of parts of shoes. In this study, the injection mold of shank which is a one of the parts of shoes has been designed. The position of gate and the injection procedure have been optimized by a simulation using the CAE software and an analysis using the DOE. As a result, the improved injection mold of shank has been manufactured in a short time. Appling the CAE and the DOE at the process of the injection mold design eventually lead an increase in the productivity and the quality of parts.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1160-1164
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• 2004

Generally in the case of parts used for precision products, tolerance of parts is very small. So inaccuate size of molding parts generates serious problems. Therefore, it's necessary to secure data about shrinkage on each condition or study about manufacturing process which reduces shrinkage. To apply MCPs to manufature of plastic product, this paper verifies how the amount of gas and Talc can affect to cell-morphology, and examines the relation between shrinkage and cell-morphology by using ASTM specimen formed by MCPs process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1645-1652
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• 2002

The failure analysis on fractured parts is divided into the qualitative method by naked eyes and metallurgical microscope etc. and the quantitative method by SEM and X-ray diffraction etc. X-ray fractography can be applied to contaminated surface as well as clean surface and gain the plastic deformation and the residual stress near the fractured surface. Turbine blade is subject to cyclic bending force by steam pressure and suffers fatigue damage according to the increasing operating time. Therefore, to clean up the fracture mechanism of torsion-mounted blade in nuclear plant, the fatigue and the X-ray diffraction test was performed on the 12%Cr steel fur turbine blade and the fractured parts. The correlation of X-ray parameter and fracture mechanics parameter was determined, and then the load applied to actual broken turbine blade was predicted. Failure analysis was performed by contact stress analysis and Goodman diagram of torsion-mounted blade.

• Journal of Ocean Engineering and Technology
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• v.12 no.2 s.28
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• pp.57-64
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• 1998

This study is concerned with criterion for membrane to shell conversion in two-dimensional elastic-plastic finite element analysis using membrane/shell mixed element. It is well known that in the sheet metal forming some parts of the sheet deform under almost pure stretching (membrane) conditions, whereas other parts in contact with sharp tooling surfaces can develop significant bending strains. The membrane analysis has a short computational time however, in the membrane analysis the bending effects can not be condidered at all. On the other hand, the shell analysis allows the consideration of bending effects, but involves too much computational time. So Onatel),2), Yang et al3),4) developed the membrane/shell mixed element. Onate introduced the energy ratio parameter and Yang et al introduced the ratio of thickness to radius of curvature as the criterion. In the present study we propose a new criterion by using the angle between both side elements in the nodal point.