• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.4
• /
• pp.179-185
• /
• 2012

When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation among injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects was differentiated according to the various relations of the above conditions. In this research, in order to optimize casting design of an automobile part (Gear Box) Computer Aided Engineering (CAE) was performed by using the simulation software (Z Cast). The simulation results were analyzed and compared with experimental results. During the mold filling, internal porosities caused by air entrap were predicted and reduced remarkably by the modification of the gate system and the configuration of overflow. With the solidification analysis, internal porosities caused by the solidification shrinkage were predicted and reduced by the modification of the gate system. For making a better production die casting tool, cooling systems on several thick areas are proposed in order to reduce internal porosities caused by the solidification shrinkage.

• Design & Manufacturing
• /
• v.14 no.3
• /
• pp.57-62
• /
• 2020

In the drug delivery system industry, the technology with even split injection becomes important for maximizing efficiency and minimizing the side effects. In conventional drug delivery system, infection can occur due to pain and splashing. Also, various applications are impossible due to disposable use, and it is the reason to avoid to use this system because of the complexity of the driving method. Therefore, in this study, a painless drug delivery device is developed for non-pain with electrical insulation breakdown method. Finite elements analysis was used to evaluate the ejection characteristics of drugs according to the shape of the micro ejection nozzle. The effect of the number of holes in the micro nozzle, the length of the nozzle and the inner shape of the nozzle on the drug discharge characteristics were analyzed.

• Design & Manufacturing
• /
• v.11 no.3
• /
• pp.35-40
• /
• 2017

PCR(Polymerase chain reaction) is a technique to replicate and amplify a desired part of DNA. It is used in various aspects such as DNA fingerprint analysis and rare DNA amplification of an extinct animal. Especially in the medical diagnosis field, it provides various measurement methods at the molecular level such as genetic diagnosis, and is a basic tool for molecular diagnostics. The internal shape of the plastic vial tube for PCR analysis used in the DNA detection process, and the surface roughness and internal cleanliness can affect detection and discrimination results. The plastic vial tube demanded by the developer of the PCR analysis equipment should be changed to a structure that eliminates the residual washing solution in the washing process to ensure the internal cleanliness. Thus the internal structure and the internal surface design for improving the PCR amplification efficiency are key issues to develop the plastic vial tube for the DNA detection process.

• Design & Manufacturing
• /
• v.9 no.2
• /
• pp.25-29
• /
• 2015

This paper presented characterization of spray velocity and angle of spray nozzle systems for cosmetic products. Diameter and length of nozzle orifice were chosen as shape factors of the spray system. Spray orifice of the spray pattern is a factor influencing the quality of the product. Fluid analysis was conducted by using "Fluent" to obtain spray angle and velocity. RSM (Response Surface Method) was used to approximate the relationship between these 2 factors and spray characteristics. To evaluate the proposed method, experimental work with existing was conducted and good agreement between simulation and experimental results.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.4
• /
• pp.637-643
• /
• 2002

The objective of this study is to provide a simple methodology to find optimum processing conditions to fabricate sub-micron structured DVD-RAM substrates with superb optical and geometrical properties. It was fecund that the birefringence, which is regarded as one of the most important optical properties for an optical disk, was very sensitive to the mold wall temperature history. Also, the integrity of the replication, represented by the land-groove structure and the radial tilt were influenced by the mold temperature and the compression pressure. A set of optimum conditions were obtained by applying Design of Experiment and the objective functions composed of three different objectives.

• Design & Manufacturing
• /
• v.13 no.3
• /
• pp.41-47
• /
• 2019

In conventional machining, the use of cutting fluid is essential to reduce cutting heat and to improve machining quality. However, to increase the performance of cutting fluids, various chemical components have been added. However, these chemical components during machining have a negative impact on the health of workers and cutting environment. In current machining, environment-friendly machining is conducted using MQL (minimum quantity lubrication) or cryogenic air spraying to minimize the harmful effects. In this study, the injection nozzle that can combined injecting minimum quantity lubrication(MQL) and cryogenic gas was designed and the shape optimization was performed by using computational fluid dynamics(CFD) and design of experiment(DOE). Performance verification was performed for the designed nozzle. The diameter of the sprayed fluid at a distance of 30 mm from the nozzle was analyzed to be 21 mm. It was also analyzed to lower the aerosol temperature to about 260~270K.

• Korean Journal of Materials Research
• /
• v.31 no.11
• /
• pp.601-607
• /
• 2021

Laser cladding a surface treatment process that grants superior characteristics such as toughness, hardness, and corrosion resistance to the surface, and rebuilds cracked molds; as such, it can be a strong tool to prolong service life of mold steel. Furthermore, compared with the other similar coating processes - thermal spray, etc., laser cladding provides superior bonding strength and precision coating on a local area. In this study, surface characteristics are studied after laser cladding of low carbon steel using 18%Cr-2.5%Ni-Fe powder (Rockit404), known for its high hardness and excellent corrosion resistance. A diode laser with wavelength of 900-1070 nm is adopted as laser source under argon atmosphere; electrical power for the laser cladding process is 5, 6, and 10 kW. Fundamental surface characteristics such as crossectional microstructure and hardness profile are observed and measured, and special evaluation, such as a soldering test with molten ALDC12 alloy, is conducted to investigate the corrosion resistance characteristics. As a result of the die-soldering test by immersion of low carbon alloy steel in ALDC12 molten metal, the clad layer's soldering thickness decreases.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.6
• /
• pp.52-57
• /
• 1999

Funtional metal prototypes are often required in numerous industrial applications. These components are typically needed in the early stage of a project to determine form, fit and function. Recent R/P(Rapid Prototyping) part are made of soft materials such as plastics, wax, paper, these master models cannot be employed durable test in real harsh working environment. Parts by direct metal rapid tooling method, such as laser sintering, by now are hard to get net shape, pores of the green parts of powder casting method must be infiltrated to get proper strength as tool, and new type of 3D direct tooling system combining fabrication welding arc and cutting process is reported by song etc. But a system which can build directly 3D parts of high performance functional material as metal part would need long period of system development, massive investment and other serious obstacles, such as patent. In this paper, through the rapid tooling process as silicon rubber molding using R/P master model, and fabricate wax pattern in that silicon rubber mold using vacuum casting method, then we tranlsated the wax patterns to numerous metal prototypes by new investment casting process combined conventional investment casting with rapid pototyping & rapid tooling process. with this wax-injection-mold-free investment casting, we developed new investment casting process of fabricating numerous functional metal prototypes from one master model, combined 3-D CAD, R/P and conventional investment casting and tried to expect net shape measuring total dimension shrinkage from R/P part to metal part.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.1
• /
• pp.1-7
• /
• 2019

In the modern industrial period, the introduction of mass production was most important progress in civilization. Die-casting process is one of main methods for mass production in the modern industry. The aluminum die-casting in the mold filling process is very complicated where flow momentum is the high velocity of the liquid metal. Actually, it is almost impossible in complex parts exactly to figure the mold filling performance out with the experimental knowledge. The aluminum die-castings are important processes in the automotive industry to produce the lightweight automobile bodies. Due to this condition, the simulation is going to be more critical role in the design procedure. Simulation can give the best solution of a casting system and also enhance the casting quality. The cost and time savings of the casting layout design are the most advantage of Computer Aided Engineering (CAE). Generally, the relations of casting conditions such as injection system, gate system, and cooling system should be considered when designing the casting layout. Due to the various relative matters of the above conditions, product defects such as defect extent and location are significantly difference. In this research by using the simulation software (AnyCasting), CAE simulation was conducted with three layout designs to find out the best alternative for the casting layout design of an automotive Oil Pan_BJ3E. In order to apply the simulation results into the production die-casting mold, they were analyzed and compared carefully. Internal porosities which are caused by air entrapments during the filling process were predicted and also the results of three models were compared with the modifications of the gate system and overflows. Internal porosities which are occurred during the solidification process are predicted with the solidification analysis. And also the results of the modified gate system are compared.

• Composites Research
• /
• v.24 no.4
• /
• pp.41-47
• /
• 2011

This paper deals with anisotropic property and structural analysis for short fiber reinforced plastic composites manufactured by the injection molding process. The common approach for modeling this type of material is the consideration of the material as homogenous and isotropic. However, the common isotropy approach often results in unexpected failure. To overcome this, new structure analysis methodology was developed in order to consider fiber orientation effect using injection mold flow analysis and Halpin-Tsai equations for unidirectional composites and taking an orientation average. The numerical predictions are compared to experimental data for tensile specimen. The predicted mechanical properties agree well with experimental data for fiber orientation and weld line effect. The analysis system was also applied to an automobile part. The proposed anisotropic model predicted different mechanical properties by position of the part and different mechanical performance of the part was changed according to injection gate position.