• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.403-404
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.335-340
• /
• 2001

We use so many plastic products in everyday. Because polymer materials have a lot of merits including low cost and easiness of forming, they are widely used in many manufacturing industries. Microcellular foaming process was developed at MIT in 1980's to save a quantity of materials and increase mechanical properties. The improvement of strength is very important factor in relation with the reduction of mass. So the first purpose of this research is to improve the strength of the microcellular foamed plastics as variation of glass-fiber's volume friction. Also the characteristic of filler such as glass-fiber was presented in a microcellular foaming process.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.896-899
• /
• 2002

Microcellular foaming Process has several merits, impact strength elevation, thermal insulation, noise insulation, and raw material saving etc. This method make the glass transition temperature of polymers low, and diminish the residual stress of polymers. This characteristics of Microcellular foaming process influences the physical properties of recycled polymers. This paper describes about the impact strength change of Microcellular foamed recycled ABS.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1233-1234
• /
• 2013

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.9
• /
• pp.18-24
• /
• 1999

Microcellular foaming is being researched as a method of maintaining and improving the mechanical characteristics of plastics as well as saving the material costs. This can not only improve the mechanical properties including impact strength of plastic by producing cells with the size of few ${\mu}$m diameters within the plastic, but also can save the material cost of plastic products with the general volumetric expansion of 2 to 10 times. But quite a long time is required for the gas to be absorbed in the plastic. Therefore consistent research should be done to reduce the saturation time of gas into the plastic and this paper provides the method of water microcellular foaming process as one of the methods using the high diffusivity of water. In addition, we can improve impact property of foamed plastic by using this method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.769-770
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.55-56
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.183-184
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1630-1635
• /
• 2005

The microstructure of the parts made by the microcellular injection molding process influence properties, including impact strength, tensile strength and density of material. Microstructure of microcellular plastics is divided into core foaming region and solid skin region. Core foaming region is influenced by pressure drop rate, viscosity and cell coalescence. However, actual mechanism of the skin layers is not known despite its importance. The study on the skin layer is getting important because foaming rate of the plastics is determined by the thickness ratio of the skin layer. Especially in case of large molded part, control of the skin layer is needed because skin layer thickness is changed largely. Therefore it is necessary to study variation in skin layer thickness with processing parameters. In this paper, the influence of temperatures in the mold cavity on the skin layer s thickness was also addressed. In addition, the relationship between the temperature distributions across cavity of the mold with impact strength on parts made with the microcellular injection molding process was addressed. In addition, the method to predict the variation in skin layer thickness with mold temperature is discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.585-590
• /
• 1997

Conventional foaming process has defects such as lower mechanical properties than ur~foaming material due to non-uniform cell distribution and environmental pollution problem caused by chemical blowing agency. So, a new foaming process such as Microcelluar plastics has been introduced to use inactive gases as a foaming agency. In order to apply Microcellular plastics for mass production process system such as extrusion, injection molding and blow molding, it needs to predict the change in material properties of polymer according to the amount of meltingas. In Polymer molding applying Microcelluar plastics, the change of viscosity among several material properties is the most important factor. Therefore, this paper is aimed to establish the method which not only finds out but also predicts the change of viscosity of ABS(Acrylonitri1e Butadiene Styrene) resin according to inert gas amount in extrusion molding.