• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.101-101
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• 2004

초미세 발포 플라스틱(MCPs; Microcellular Plastics)공정은 기존 발포 플라스틱의 장점을 보존하면서도 그 동안 발포 플라스틱의 단점으로 지적되어온 충격강도, 인성, 경도 등의 기계적 특성저하를 개선하기 위하여 개발되었다. 플라스틱 내에 지름 수 십 $\mu\textrm{m}$ 내외의 기포를 $10^{9}$-$10^{15}$cel1/㎤의 밀도로 발생시키는 초미세 발포공법은 내부의 미세 구조로 인하여 재료비를 절약하면서 우수한 기계적 특성을 나타내는 플라스틱 재료를 성형할 수 있게 하며, 발포제로 초 임계 상태의 불활성 기체($CO_2$, $N_2$, etc)를 사용하기 때문에 기존의 발포 공정에서 발포제로 사용했던 유해 화학 물이나 프레온, 부탄으로 인해 발생할 수 있는 환경 문제를 해결할 수 있다는 장점을 지닌다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.77-77
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• 2004

현재 플라스틱 제품의 재료 절감을 통한 원가 절감과 아울러 기계적 성질을 더 향상시키거나 유지하기 위한 초미세 발포 공법이 주목받고 있다. 이론 위해 많은 연구가 진행되어 왔으나 아직까지도 셀의 미소화, 균일화 그리고 표면 품위 등을 위한 지속적인 연구가 요구되고 있다. 초미세 발포 사출에서 셀의 형상에 영향을 주는 인자는 여러 가지이다 우선 사출 속도에 영향을 받으며, 사출 온도에 따라서도 많은 영향을 받는다.(중략)

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.853-858
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• 2001

Generally, mixed materials of LDPE, EVA and foaming agent are manufactured by crosslinking foaming or chemical foaming process. Above materials were used in a microcellular foaming injection molding process. Influence of each factor such as injection type, temperature of barrel, rate of mixed materials and contents of foaming agent was estimated by DOE(Design of Experiments). As a result of experiments, injection type and rate of LDPE, EVA have an influence on foaming rate. This data can be used in field of application of LDPE and EVA.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.263-268
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• 2001

MCPs means Micro Cellular Plastics. The micro-cells are generated in the products by the difference of dissolution through the pressure drop after super critical fluid of CO2 or N2 dissolves into polymer. We have developed injection molding process adopting MCPs and applied it to a broad range of injection molded thermoplastic materials and applications. It can prevent the leakage of impact strength and increase the thermal conductivity, moreover regulate the thermal conductivity. Then we can develop the high strength foaming plastics. Also, it can be gained a competitive advantage by utilizing its processing benefits, e.g. the lightweight products and significant reductions in material consumption.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.367-372
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• 2000

By the means of microcellular (earning, we can make polymers with $10{\mu}m$ sized gas bubbles. After the $CO_2$ gas bubbles solve, diffuse and leave the polymer matrix, the thermal properties of polymer matrix are changed. Expecially, thermal conductivity becomes low. So, the polymer matrixes with gas bubbles can be used as insulator In this paper, we make model after microcellular foamed polymer matrix to know the change of thermal properties. Most of all, the purpose of this paper is the mlcrocellular foamed polymer matrix's availability as a insulator Beside of thermal properties the surface of microcellular foamed polymer is polished and easy to be colored. Above all the mechanical properties are better than the other insulator. So, microcellular foamed polymer can be used as exterior of building or it can be replaced as a tile.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.621-626
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• 2001

Microcellular foaming process was developed at MIT in 1980's to save a quantity of raw materials and improve mechanical properties. There are many process variables in appling microcellular foaming process to the conventional injection molding process. Of all process variables, part dimension control and shrinkage are the most influential on the post molded dimension. The post molding dimensional change of thermoplastic resins is important to tool designers for predicting the specific difference of molded part vs. actual mold cavity. Generally, articles injection molded are smaller in size than the cavity; hence, the term shrinkage factor is used to define the allowance a designer specifies. It is important to consider the factors that influence molded part dimension. According to ASTM Designation: D 955, shrinkage from mold dimensions of molded plastics was measured. In injection molding, the difference between the dimensions of the mold and of the molded article produced therein from a given material may vary according to the design and operation of the mold. In this paper, shrinkage data of molded plastic parts was obtained. It can be an important information for designing optimum mold system in a microcellular foaming injection molding process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.341-345
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• 2001

New technoloty called microcellular foaming process was developed at MIT in 1980's. Although it has many good things, it could not be used it all sides of manufacturing plastics. Because it takes a long time for making foamed goods. So microcellular foaming injection molding process appeared to solve this problem. The first purpose of this research is to measure the impact strength as foaming magnitude of microcellular foamed plastics. There are two methods such as batch process and microcellular foaming injection molding process in making foamed plastics. According to the experimental data, the impact strength of each specimen was measured to find out the influence of foaming magnitude of microcellular foamed plastics.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.196-201
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• 2000

There is a great demand for reducing the amount of material used in mass-produced plastics parts for material cost constitutes a large percentage of the total cost of a product up to 75% It may be noted that the price of plastics is directly related to the price of petroleum. Material reduction therefore decreases the amount of oil needed for the manufacture of plastics and thus help conserve this natural resource. Therefore microcellular foaming process(MCPs) was studied for solving this problems alternatively in 1980's at M. I. T. Until now in microcellular plastics processes carbon dioxide gas was mainly used for microcellular foaming Because carbon dioxide has more solubility than any other gases such as nitrogen gas or helium gas. The purpose of the this research is measurement of changing of the microcellular plastics' weight by using nitrogen gas in injection molding an comparing weight reduction of microcellular foamed plastics for using carbon dioxide gas with nitrogen gas.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1414-1417
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• 2003

In chemical forming process, mixed materials of LDPE, EVA and forming agent are used. However mechanical properties has been dropping remarkably through this forming process. In this study, Above materials(LDPE, EVA) were used in microcellular foaming injection process. And various effective factors in this process were selected by Axiomatic approach and systematically estimated by DOE(Design of Experiments). As a results, injection type and rate of mixing resins have more influence on forming rate than other factors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.213-214
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• 2008