• 환경사랑
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• s.25
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• pp.13-13
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• 2001

가전 제품의 포장용 완충재 연도별 회수$\cdot$재활용$\cdot$처리 및 감량화 지침에 따라 삼성, LG를 비롯한 대형 가전사는 자체적으로 역회수 재활용 시스템을 운영하고 있다. 삼성전자 가전 제품의 스티로폴 포장재 회수 사업을 담당하고 토로스물류의 이진공 대리를 통해 알아보았다.

• Journal of Korea Foundry Society
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• v.26 no.6
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• pp.272-276
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• 2006

For the first time AZ91 (MgAl9Zn1) and AM60 (MgAl6) Mg alloy foams with homogeneous pore structures were prepared successfully via melting foaming method by using $CaCO_3$ powder as blowing agent. The possible foaming mechanisms and pore structures of these Mg alloy foams were discussed and investigated. The results show that Mg alloy melt can affect $CaCO_3$ decomposition behavior and AZ91 Mg alloy is relative easy to be foamed into metal foam with high porosity and big pore size.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.187-187
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• 2010

최근 해상풍력 블레이드가 대형화됨에 따라 보다 가볍고 강한 재료가 요구되고 있다. 현재 주로 사용되고 있는 복합재는 발사우드나 PVC 폼 등을 코어소재로 하고, 유리섬유나 탄소섬유 등을 보강섬유로 사용하고 있다. 본 연구에서는 현재 사용되고 있는 복합재에 대한 특성을 알아보고, 최근 흡음, 충격 및 열에 강한 발포 알루미늄을 이용한 복합재를 해상풍력 블레이드 제조에 적용하여, 구조 강도 실험을 실시함으로써 기존 복합재와 구조 강도 및 비용 등을 비교 검토하여 우수한 복합재를 제시하고자 한다. 이를 위해 대형구조물인 블레이드를 제작하기 위해 적절한 크기의 발포 알루미늄을 상호 접합하기 위한 방법을 연구하고자 하며, 목포대학교에서 보유중인 만능재료시험기(100 Ton)를 활용하여 인장, 압축, 굽힘 실험을 실시하고, 스킨재 변화, 코어재의 밀도와 두께 변화를 고려하여 다양한 복합재의 강도를 비교하고자 한다. 또한, 기존에 사용되고 있는 복합재와 발포 알루미늄을 이용한 복합재의 재료비 및 가공비를 추정하고 경제적인 복합재를 제시하고자 한다.

• 환경사랑
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• s.35
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• pp.3-3
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• 2003

• Composites Research
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• v.27 no.2
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• pp.42-46
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• 2014

In the present study, impact tests were carried out to investigate the crashworthy behaviour of the expanded polypropylene under the constant incident energy (100 J and 200 J) with five different combinations of striker mass and velocity. Also, preliminary quasi-static test was performed to obtain basic characteristics of the expanded polypropylene. MTS 858 and Instron dynatup 9250 HV were used for the quasi-static test and impact tests, respectively. In consequence, it was found that the impact energy absorption characteristics of the expanded polypropylene was more influenced by the striker mass instead of the velocity of the striker.

• Applied Chemistry for Engineering
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• v.17 no.4
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• pp.357-360
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• 2006

In this study, we studied the physical properties and application of PF foam as heat insulating materials. In the experimental results, the density of PF foam showed $0.030g/cm^3$ and the thermal conductivity showed $0.026kcal/m.h.^{\circ}C$. Also, thermal resistance of the prepared PF foam was volatilized about 71.7 wt% when the temperature was $500^{\circ}C$ (1 h). And the chemical structure of PF foam have a closed cell type in the important properties as heat insulating materials. Therefore, it was confirmed that the prepared PF foam had excellent performance as heat insulating materials.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.6
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• pp.266-273
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• 2011

Foamed glass was fabricated by using glass powder and foaming agents. For the glass powder, we used sodalime glass which's manufactured by using refused coal ore obtained as by-product from Dogye coal mine in Samcheok. And for the foaming agents, we used Calcium carbonate, Calcium phosphate and powder of shale type refused coal ore itself which has high content of carbon materials. We additionally used liquid binder for forming, and mixed together. And we formed rectangular shape and treated $800^{\circ}C$ for 20 min in an electrical furnace. The various kinds of foam glass samples were fabricated according to the kinds of foaming agents. The physical properties of samples, as specific gravity and compressive strength, were measured. Pore structure of each samples were investigated too. Foam glass with specific gravity of 0.4~0.7 and compressive strength of 30~72 kg/$cm^2$. Especially we get satisfying foam glass sample with low specific gravity of 0.47 and high compressive strength of 72 kg/$cm^2$ by the use of liquid calcium phosphate as foaming agent. It also had small and even shape of pore structure. Therefore, it is concluded that refused coal ore can be used for raw materials to manufacture secondary glass products such as a foamed glass panel for construction and industrial materials.

• Polymer(Korea)
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• v.29 no.6
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• pp.605-612
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• 2005

This study investigates the isothermal crystallization behaviors of polypropylene-polyethylene-(1-butene) terpolymer and the adiabatically expanded polyolefin structured foams. For this purpose, butane gas was used as a physical blowing agent. Avrami equation has been used to interpret theoretically the experimental results obtained by either DSC or polarized optical microscope. It is believed that elongation induced crystallization occurring during the adiabatic expansion process has resulted in an increase in crystallization rate, eventually leading to a faster growth rate of spherulites and an increase in the nucleation density. An analysis of the foam by SEM images showed that the structure of foam is uniform (below diameter 30 $\mu$m closed cell) In addition, the thermal conductivity and the compressive strength of the polyolefin structured foams was measured. The thermal conductivity of foamed resin with excellent insulation characteristics is reduced compared with unfoamed resin. The compressive strength is decreased with increase in the expansion ratio.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.5
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• pp.199-205
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• 2018

A geopolymer was produced from coal ash generated from an integrated gasification combined cycle (IGCC) plant and its water resistance was evaluated. For this purpose, the geopolymer specimens were immersed in water for 30 days to measure changes in microstructure and alkalinity of the immersion liquid. Particularly, the experiment was carried out with foaming status of the geopolymers and parameters of room temperature aging condition, and immersion time. The foamed geopolymer containing 0.1 wt% Si-sludge had pores with a diameter of 1 to 3 mm and exhibited excellent foamability. Also, the calcium-silicate-hydrate crystal phase appeared in the foamed geopolymer. In the geopolymer immersion experiment, the pH of the immersion liquid increased with time, because the un-reacted alkali activator remained was dissolved in the immersion liquid. From the pH change of the immersion liquid, it was found that geopolymer reaction in the foamed specimen was completed faster than the non-foamed specimen. Through this study, it was possible to successfully produce foamed and non-foamed geopolymers recycled from IGCC coal ash. Also the necessary data for the safe application of IGCC coal ash-based geopolymers to areas where water resistance is needed were established; for example, the process conditions for room temperature aging time, effect of foaming status, immersion time and so on.

• Polymer(Korea)
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• v.32 no.2
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• pp.183-188
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• 2008

Reinforced open cell micro structured foams were prepared by the polymerization of high internal phase emulsions incorporating inorganic thickeners. Organoclays were used as oil phase thickener, and sodium montmorillonite was used as aqueous phase thickener. Rheological properties of emulsions increased as oil phase thickener concentration and agitation speed increased, due to the reduced drop size reflecting both competition between continuous and dispersed phase viscosities and increase of shear force. Drop size variation with thickener concentration could be explained by a dimensional analysis between capillary number and viscosity ratio. Upon the foams polymerized by the emulsions, compression properties, such as crush strength and Young's modulus were measured and compared. Among the microcellular foams, the foam incorporated with an organoclay having reactive group showed outstanding properties. It is speculated that the exfoliated silicate layers inside polystyrene matrix, resulting in nanocomposite foam, are the main reason why this foam has enhanced properties.