• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.223-226
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• 2009

The plastics are widely utilized in the inside of vehicles. The dynamic tensile characteristics of auto-body plastics are important in a prediction of deformation mode of the plastic component which undergoes the high speed deformation during car crash. This paper is concerned with the dynamic tensile characteristics of the auto-body plastics at intermediate strain rates. Quasi-static tensile tests were carried out at the strain rate ranged from 0.001/sec to 0.01/sec using the static tensile machine(Instron 5583). Dynamic tensile tests were carried out at the strain rate ranged from 0.1/sec to 100/sec using the high speed material testing machine developed. Conventional extensometry method is no longer available for plastics, since the deformation of plastic is accompanied with localized deformation. In this paper, quasi-static and dynamic tensile tests were performed using ASTM IV standard specimens with grids and images from a high speed camera were analyzed for strain measurement. True stress-strain relations and the actual strain rates at each deformation step were obtained by processing load data and deformation images, assuming the plastics to deform uniformly in each grid.

• 콘크리트학회논문집
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• 제18권2호
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• pp.219-226
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• 2006

본 연구에서는 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 압축, 휨 및 충격강도, 흡수율 및 동결융해저항성에 미치는 결합재 첨가량 및 PA 혼입량의 영향에 대하여 연구하였다. 그 결과 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 압축, 휨 및 충격강도는 PA 혼입량에 관계없이, 결합재 첨가량 및 충전제 혼입량의 증가에 따라 증가하는 경향을 나타냈다. 하지만, PA 혼입량의 증가에 따라서는 감소하는 경향을 보였다. 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 흡수율은 PA 혼입량에 관계없이, 결합재 첨가량의 증가에 따라 감소하는 경향을 나타냈다. 하지만 PA 혼입량의 증가에 따라서는 증가하는 경향을 나타냈다. 복합 재질 폐플라스틱을 재활용한 폴리머콘크리트의 내구성 지수는 결합재 첨가량의 증가에 따라 증가하였으나, PA 혼입량에 따라서는 감소하는 경향을 보였다.

• 자원ㆍ환경경제연구
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• 제30권2호
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• pp.269-297
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• 2021

바이오플라스틱은 탄소중립적이며 생분해가 가능하다는 점에서 기존 플라스틱의 대체재로 주목받고 있다. 이 연구는 일국 축차동태 연산가능일반균형 모형을 사용하여 석유 기반 플라스틱산업 규제와 바이오플라스틱산업 육성에 따른 경제적 환경적 파급효과를 추정하였다. 분석결과, 플라스틱산업 규제 시 온실가스 감축과 폐기물 감소 효과가 나타나 긍정적인 환경적 파급효과가 발생한 반면, GDP는 감소하여 경제적으로는 부정적인 파급효과를 확인할 수 있었다. 한편 플라스틱산업 규제와 바이오플라스틱산업 육성이 동시에 이루어지는 경우, 플라스틱 산업 규제만 시행하는 시나리오와 비교하여 유사한 수준의 온실가스 감축과 폐기물 감소효과가 발생했으나 바이오플라스틱산업 생산 확대가 기존의 경제적 손실을 상쇄시켜 GDP를 증가시키는 것으로 나타났다. 따라서 바이오플라스틱 생산 확대를 통해 석유 기반 플라스틱을 대체해 나간다면 온실가스 배출 및 플라스틱 폐기물 발생과 같은 환경문제를 개선하면서 경제성장을 가능하게 하는 탈동조화(decoupling)에 기여할 수 있을 것으로 판단한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 The Korea-Japan Plastics Processing Joint Seminar
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• pp.49-57
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• 2003

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.217-220
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• 2003

Due to the lighter weight and the higher freedom of design than metals plastics have been spot lighted in a wide number of applications. In the making plastic parts injection-molding process is one of the most general methods. During the injection molding process, filling-packing-cooling process, plastics have exposed to several external stresses and then plastic parts injected have molding effects which are known as anisotropic properties, orientation, and residual stress. Those molding effects are often shown as unexpected phenomena which are warpage, strength decrease, stiffness reduction, etc. In case of glass fiber filed plastics these effects are more significant than the ufilled ones. Therefore the molding effects have to be considered in the parts design using glass fiber reinforced plastics. We have developed the interface program in order to consider the molding effects in structural analyses of plastic parts using Heirarchical structural searching and layer handling in direction of thickness algorithm. The advantages of this program are the freedom of FE mesh between molding and structural analysis, the variable layer to the thickness direction of parts and the conveniences of data transferring and checking

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.991-996
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• 2004

Plastics are widely used in industry, because they are light, easily manufactured, and have high specific strength. And many researches to increase the strengths and to reduce the price are being conducted at now. One of these researches is concerning to additives. Foaming techniques are used to endow insulation properties, to improve specific strength, or reduce the material cost. Due to their unique properties, foamed plastics are applied to refrigerator, pipe, and insulators. Micro-cellular foaming is the latest foaming technique that was invented at 1980 in MIT. It is known that many tiny small cells are generated in the polymer matrices and micro-cellular foamed plastics show relatively high specific strength. We investigated the role of CaCO3 which is one of the most widely used additives in plastics industry as an additive for nucleation in view of cell morphology. CaCO3 used in this paper was treated to increase the dispersibility and to lower the density, so it has many pores at his body. Two experiments were conducted, in order to check the role of an additive for nucleation. One is compound-ability and the other one is role of nucleation agents.

• ALGAE
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• 제31권4호
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• pp.289-301
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• 2016

Floating debris provides substrates for dispersal of organisms by ocean currents, including algae that thrive on plastics. The 2011 earthquake and tsunami in Tohuku, Japan resulted in large amounts of debris carried by the North Pacific Current to North America from 2012 to 2016. In 2015-2016, the plastics in the debris bore a complex biota including pink algal crusts. One sample (JAW4874) was isolated into culture and a three-gene phylogeny (psbA, rbcL, and SSU) indicated it was an unknown member of the red algal class Stylonematophyceae. It is a small pulvinate crust of radiating, branched, uniseriate filaments with cells containing a single centrally suspended nucleus and a single purple to pink, multi-lobed, parietal plastid lacking a pyrenoid. Cells can be released as spores that attach and germinate to form straight filaments by transverse apical cell divisions, and subsequent longitudinal and oblique intercalary divisions produce masses of lateral branches. This alga is named Tsunamia transpacifica gen. nov. et sp. nov. Sequencing of additional samples of red algal crusts on plastics revealed another undescribed Stylonematophycean species, suggesting that these algae may be frequent on drift oceanic plastics.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.597-601
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• 2001

Waste plastics amount is more than 3.5 million tons and 30% of industrial waste in 1998, Korea but recycling rate of industrial waste plastics is quite low because the material separation technology from the mixed waste plastic powders is not commercially available so far. This study covers the triboelectrostatic separation of polyvinylchloride (PVC) materials collection chambers and controllers. PVC and PET powders can be imparted negative and positive surface charges, respectively, due to the difference of triboelectric charging series between particles and particles in the fluidized bed tribocharger, and can be separated by passing them through an external electric field. The extract content and yield of PVC separation from the mixed PVC and PET plastic powders are 90.0% and 98.2%, respectively. The electrostatic separation system using the fluidized bed tribocharger shows the potential to be an effective method for removing PVC materials from other mixed plastics.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.730-733
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• 2001

Separation of PET and PVC is a key technology to achieve effective plastics recycling but no efficient and economically feasible method has been developed yet. The application of flotation was investigated by many researchers but the causes of the selectivity were not clarified. This paper described the adsorption mechanism of wetting agents onto plastics, using the agents which have various polarity and hydrocarbon chain length. It was found that (1) hydrophobic interaction played a predominant role for the adsorption, (2) anionic wetting agents could be adsorbed onto negatively charged plastics with the polar radicals oriented outer part of the plastics, then often depressed plastics more effectively than cationic agents, and (3) PET and PVC could be separated with dodecyamine hydrochloride and sodium dodecyl- sulfonate in the concentration ranges of 1.0$\times$10$^{[-10]}$ $^{6}$ -5.0$\times$10$^{[-10]}$ $^{5}$ and 2.0$\times$10$^{[-10]}$ $^{6}$ -1.0$\times$10$^{[-10]}$ $^{5}$ mo1/1, respectively.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.499-509
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• 2014

Wood filler is a porous and anisotropic material having different size, shape, and aspect ratio. The use of wood fillers such as wood particle, wood flour, and wood pulp in wood plastic composites (WPCs) are growing rapidly because these wood fillers give improved strength and stiffness to WPCs. However, the wood fillers have originally poor compatibility with plastic matrix affecting the mechanical properties of WPCs. Therefore, to improve compatibility between wood and plastic, numbers of physical and chemical treatments were investigated. While the various treatments led to improved performances in WPC industries using petroleum-based plastics, full biodegradation is still issues due to increased environmental concerns. Hence, bio-based plastics such as polylactide and polyhydroxybutyrate having biodegradable characteristics are being applied to WPCs, but relatively expensive prices of existing bio-based plastics prevent further uses. As conventional processing methods, extrusion, injection, and compression moldings have been used in WPC industries, but to apply WPCs to engineered or structural places, new processing methods should be developed. As one system, co-extrusion technique was introduced to WPCs and the co-extruded WPCs having core-shell structures make the extended applications of WPCs possible.