• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.149-158
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• 2004

In most RP processes, the inherent stair-stepped surfaces and shrinkage-induced warping of the parts require post processing such as surface finishing. To minimize such defects, VLH-ST, a newly developed RP process, employs a 3.9-mm thick expandable polystyrene (EPS) foam sheet and a hot wire to contour it to have slant linear-interpolated sides. The use of relatively thick sheets for layers, however, limits the process capability of constructing fine details, especially smaller than the layer thickness. This study is focused on the development of a post processing method fo fine details of VLM-ST parts. The post-processing tool was designed to meet all the requirements for the desirable post processing. It adopted a hot wire as a means of melting the EPS foam sheet. Various basic experiments on the post processing were carried out to obtain the optimal process conditions. The dominant process parameters such as the radiated heat input, the tool speed, and the gap between the tool tip and the foam sheet (tool height) were considered in the experiments. The effectiveness of the developed post-processing method fo forming or engraving fine details on the VLM-ST parts has been thus demonstrated. The experiments on engraving several sets of letters, such as CANESM, 인간, and 한국과학기술원, on the EPS foam sheet were carried out. In addition, a flowery shape was engraved on a three-dimensionally curved surface of a pottery-shape VLM-ST part.

• Food Science and Preservation
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• v.6 no.3
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• pp.260-263
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• 1999

This study was measured weight loss, total ascorbic acids, titratable acidity and soluble solids contents to investigate the effect of EPS(expended polystyrene foam) box. double wall corrugated paperboard box and LDPE film pouches during storage at 25$^{\circ}C$. The rate of weight loss was 5.7% in corrugated paperboard box after 10 days. but those of 20LD, 40LD film and EPS box were 1.0, 0.8, and 0.9%, respectively. Total ascorbic acid content and titratable acidity of EPS box was 15.0% and 24.4% higher than that in corrugated paperboard box, but the obvious differents were not observed among the LDPE film pouches and EPS box. The titratable acidity was decrease during storage, but total soluble solids content was slightly increase. Overall appearences of LDPE pouches and EPS box were boner than those of corrugated paperboard box.

• Food Science and Preservation
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• v.6 no.3
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• pp.255-259
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• 1999

This study was measured weight loss, total ascorbic acids, titratable acidity and soluble solids contents to investigate the effect of EPS(expended polystrene foam) box, double wall corrugated paperboard box and LDPE film pouches during storage at 25oC. The rate of weight loss was 5.9% in corrugated paperboard box after 7 days, but those of 20LD, 40LD film and EPS box were 1.1, 1.0, and 1.1% , respectively. Total ascorbic acid content of EPS box was 20% higher than that in corrugated paperboard box, but the obvious differents were not observed among the LDPE film pouches and EPS box. The titratable acidity was decrease during storage, but total soluble solids content was increase. Overall appearences of LDPE pouches and EPS box were better than those of corrugated paperboard box.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.127-128
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• 2021

Rigid urethane foam is widely applied because it is light and has superior insulation performance compared to insulation materials such as EPS or glass wool. However, it has the disadvantage of being vulnerable to fire. Therefore, in this study, before proceeding with the research to improve the fire resistance of the rigid polyurethane foam, we would like to investigate the change in density and thermal conductivity of the rigid polyurethane foam according to the change in the mixed weight of the main material and the curing agent. It was found that the density increased as the mixed weight increased. The thermal conductivity showed similar values overall. As for the density distribution, the central part was low and the outer part was high.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.759-762
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• 2000

Rapid Prototyping (RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of parts due to layer-by-layer stacking, low build speed caused by line-by-line solidification to build one layer, and additional post processing to improve surface roughness, so it is required very high cost to introduce and to maintain RP apparatus. The objective of this study is to develop and design a new RP process, Variable Lamination Manufacturing using expandable polystyrene foam sheet as part material (VLM-S), which can make up for the disadvantage of existing techniques, and to develop an apparatus to implement the process. In order to examine the possibility of practical utilization of the proposed VLM-S process for prototyping of a general three-dimensional shape, an auto-shift lever knob and a pyramid shape were fabricated.

• 환경사랑
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• s.38
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• pp.6-8
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• 2004

EPS 총사용량은 중국이 단연 1위이며, 유럽, 미국, 일본, 한국이 그 뒤를 잇고 있다. 단열재 소비는 중국, 유럽, 미국에 이어 한국이 뒤를 잇고 있다. 수산물상자 등 식품포장재의 소비는 유럽, 미국, 일본, 중국 등의 순이다. 가전완충재인 경우 전자제품 제조공장이 인건비가 저렴한 국가로의 이전 등으로 서유럽, 일본, 한국 등의 소비가 감소하고 있고 그 대신 중국, 동부유럽, 동남아시아, 남미 국가들의 소비량이 증가하고 있다. EPS 포장재 다소비 국가 중 재활용실적이 양호한 국가는 독일 $77\%$(에너지 회수포함), 일본 $64\%$(에너지 회수 포함), 한국 $59\%$, 프랑스 $45\%$ 순이었다. 재활용방법은 일본을 제외한 아시아지역은 재생 원료 생산 위주이나, 유럽지역에서는 원료로의 재활용 외에 원원료 회수, 에너지 회수 등 다양한 재활용방법을 이용하고 있다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.277-278
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• 2018

Improvement of insulation performance of buildings is a major part. Adiabatic method The adiabatic method minimizes the heat loss of the building. External insulation uses insulation to prevent fire. Ambient air hazards are less prone to fire. When a fire occurs, a phenolic pattern is formed and bond strength with the wall increases. EPS insulation and phenol foam were used to compare external heat transfer and external heat transfer. The heat transfer properties of phenolic foam and styrofoam were evaluated as follows. In the mortar and styrofoam structure, the problem of styrofoam reaching the burning point occurred before the collapse of the mortar, and the phenol foam had a problem in that when the direct fire was continued on the phenol foam. The characteristics of continuous infiltration appeared. In the case of mortar and phenol foam + styrofoam, the heat penetrated into the interior due to the shrinkage due to the shrinkage of the carbon screen on the phenol foam. However, when reinforced with glass mesh on the outer surface, And to reduce infiltration.

• 환경사랑
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• s.64
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• pp.4-6
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• 2012

"환경사랑"은 국내의 스티로폴(EPS)소비와 관련, 2012~2013년도의 소비 전망을 알아 보기 위해 관련업체 담당자들의 의견을 들어 보았다. 물론 현장에서 뛰고 있는 일선 담당자들에게도 향후 전망을 한다는 것은 쉬운 일이 아니다. 그럼에도 불구하고 원료업체 6개소, 가공업체 17개소, 가전업체 6개소, 식품업체 4개소 등 33개 업체의 담당자들이 조심스럽게 의견을 제시 했다. 그 결과를 정리한다.

• 환경사랑
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• s.63
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• pp.10-11
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• 2012

국회 강성천 황영철 의원이 주최하고 자원순환연대가 주관하며 한국농어민신문과 당 협회가 후원한 '농수산물 스티로폴 상자 종이스티커 재질개선 간담회'가 지난 2월 29일 국회의원회관에서 열렸다. 이날 간담회에서 EPS 포장재의 재활용률을 높이고 상품의 이미지를 제고시키기 위해 종이 스티커 대신 PS(폴리스틸렌) 필름 스티커를 붙여야 한다는 데 의견이 모아졌다. 한국농어민신문이 정리한 이날 종합토론에서 개진 된 참석자들의 의견을 발췌했다.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.26-30
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• 2005