• 한국폐기물자원순환학회지
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• 제35권8호
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• pp.709-720
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• 2018

Since the import ban of plastic waste in China has been enforced, plastic wastes were not properly collected and recycled in Korea. Hence, the management strategies for plastic waste in Korea should be improved by examining the regulations and policy in developed countries such as United States, Japan, EU and United Kingdom. The management strategy for the recycling cycle should be implemented to expand the labeling system of separation and discharge, reduce the consumption of plastic products, automate the separation and sorting method in recycling facilities, and improve the economical efficiency of the recycling cycle. The concept of residual waste (secondary waste) in the material flow analysis should be implemented to identify the shortage point in the plastic waste stream. Finally, the cooperation with international communities is required for a transboundary movement of plastic waste, which includes participation at the working group of international standards to recycle plastic waste.

• Environmental Analysis Health and Toxicology
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• 제28권
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• pp.13.1-13.5
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• 2013

Objectives: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. Methods: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals - di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)-were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. Results: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were $1.0{\times}10^{-4}$, $1.2{\times}10^{-5}$, $9.5{\times}10^{-3}$, and $5.3{\times}10^{-3}mg/L$ for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were $5.2{\times}10^{-3}$, $6.0{\times}10^{-4}$, $5.0{\times}10^{-1}$, and $2.7{\times}10^{-1}mg/kg$ for DEHP, DINP, Cd, and Pb, respectively. Conclusions: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.

• 한국화재소방학회논문지
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• 제17권1호
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• pp.76-84
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• 2003

본 연구는 산업현장에서 단열재로 .사용되고 있는 폴리스티렌 폼, 폴리우레탄 폼, 폴리에틸렌 폼과 같은 플라스틱 단열재의 화재특성을 구명하고자 하였다. 플라스틱 단열재의 화재특성은 ISO 5660에 따라 콘칼로리미터 시험을 수행하였다. 사용된 실험재료는 국내에서 생산되는 상업용 플라스틱 단열재를 사용하였고 그들의 조성은 제조자에 의해 밝혀지지 않았다. 연구 결과플라스틱 단열재의 열방출율은 재료의 밀도와 열플럭스의 증가에 따라 증가하였다. 플라스틱 단열재 중 폴리에틸렌 폼이 최대열방출율 및 평균열방출율이 가장 크게 나타났고, 열플럭스 및 밀도의 증가에 따른 최대열방출율의 증가율도 가장 큰 것으로 나타났다. 플라스틱 단열재에 의한 화재예방을 위해 제품의 종류 및 열플럭스의 크기에 따른 열방출 평가 기준을 제시하였다.

• 한국건설순환자원학회논문집
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• 제8권4호
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• pp.436-443
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• 2020

다양한 복합재질 생활계 폐플라스틱의 물질재활용 확대를 위해서는 물질재활용 제품의 용도개발 및 이들의 품질 안정성 확보 노력이 필요하다. 본 논문에서는 생활계 폐플라스틱 물질재활용 제품의 품질에 대한 안정성을 확보하기 위한 기초 연구로서 발생지역에 따른 생활계 폐플라스틱의 혼입율 특성 및 이를 활용한 물질재활용 제품의 생산시기에 따른 품질특성을 비교 검토하였다. 그 결과 발생 도시에 따른 생활계 폐플라스틱 중 재활용 가능한 폐플라스틱의 구성비율은 64.5~90.4%로서 도시별 큰 차이를 보이고 있다. 또한 4개월간 생산시기별 물질재활용 제품의 평균 인장강도는 12.33MPa, 평균 연신율은 5.94%, 평균 밀도는 1.35g/㎤, 평균 회분은 3.66%인 것으로 나타났다.

• 펄프종이기술
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• 제30권3호
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• pp.38-45
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• 1998

Soil and water contamination caused by the abundant use of agricultural chemicals including herbicides and fertilizers draws public concerns since these chemicals may pollute the agricultural lands as well as the food products grown on these lands. As a method to reduce the use of agricultural chemicals mulching with thin plastic film has been commonly practised for many years. Although use of the plastic film for mulching is very effective in preventing the growth of weed, it is almost impossible to remove all of the plastic film from the agricultural land and the remaining film eventually contaminates the soils. Therefore, it is very imperative to develop a mulching material that decomposes completely to prevent soil pollution problems and to enhance the competitive edge of domestic agriculture. Mulch papers are believed to have many positive characteristics in preventing problems caused by the plastic mulch film since it decomposes completely after use. However, the basis weight of mulch papers needs to be reduced to improve its handling properties and to reduce the raw material costs of pulps. In this paper the possibilities of using domestic old corrugated containers in producing mulch papers were examined. Also use of unbleached softwood kraft pulps and dry strength additives were exploited along with two-layered sheet forming technology in decreasing the basis weight of the mulch paper. Results showed that reduction of 20g/$m^2$ of basis weight of mulch paper was possible by the appropriate raw material selection and application of strength resin. To use the mulch papers in paddy fields, however, further research to improve its durability should be pursued.

• 기술표준
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• 통권8호
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• pp.91-102
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• 2002

• 월간포장계
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• 통권111호
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• pp.106-113
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• 2002

• 소성∙가공
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• 제19권3호
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• pp.185-190
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• 2010

Application of CAE analyses are wide spread in shaping processes and structural safety verification of plastic products. The importance of CAE analysis and its contributions are getting increase since the processibility and structural safety of product can be predicted. CAE analysis for complex shaped product need a lot of time for modeling and computation compare with simpler one. Therefore careful simulation modeling is required for complex shaped product. Structural analysis for plastic door handle of automobile has been performed and structural safety has been investigated for various load directions and modeling cases. Large stress occurred at the hinge in handle regardless of load direction and modeling case. Consequently hinge is considered structurally very weak among the parts in plastic door handle. It is concluded that simple modeling rather than total modeling with adequate boundary condition equivalent to real situation gives reasonable computational results with saving modeling effort and computation time.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.98-101
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• 1999

The plastic instable flow phenomenon happens in practical forming process I. e. upsetting backward extrusion piercing indentation. And also it is difficult to control precisely the shape and dimensions of forming process. It is found that instabilities of the process are mainly connected with imperfection in the lubrication billet eccentricity inclined punch alignment. In view of the direct relationship between instable material flow and quality defects of the products and it is for better control of forming operation we should necessarily find out their phenomena. In this study we used the friction disturbance due to inclined punch angle and introduced the method considering kinematic hardening effect Analysis of upset forging is carried out using the rigid plastic FEM and slab method with eccentricity.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.61-61
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• 2011

Polymer solar cells have become one of the rising next generation solar cells due to their potential for lightweight and bendable plastic solar modules. Recently, the power conversion efficiency of polymer solar cells has reached ~8 %, which can make ~6 % plastic solar modules when it comes to the modular aperture ratio of ~80 %. Although this efficiency is far behind that of conventional inorganic solar cells, the plastic solar modules are expected to create new energy market into which the inorganic solar modules could not make inroads. In the near future, the plastic solar modules can be integrated with consumer electronics that should overcome the regulation of energy consumption. For this application, the polymer solar cells should be fabricated in a variety of module shapes, which can be resolved by employing conventional and/or advanced coating and molding technologies of plastics products. In this tutorial, the fundamental aspect of polymer solar cells will be briefly introduced and then recent trends in terms of materials and devices will be reviewed together with showing recent results in organic nanoelectronics laboratory.