• Elastomers and Composites
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• v.46 no.4
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• pp.277-283
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• 2011

In this study, engineering grade and high intensity reflective sheets were prepared with glass beads and their reflection performance and physical properties were investigated. The reflective sheets prepared by using glass beads are divided into enclosed or encapsulated lens type, depending on whether the glass beads are open in air or not. Because of an extra layer on the glass bead surface, the enclosed lens type reflective sheets show very little change in the properties by bad weather conditions, compared to encapsulated lens type reflective sheets. Optimization of the amount of glass beads on the surface was carried out, which determines the retroreflective properties. Enclosed and encapsulated lens type reflective sheets with various colors were prepared and their coefficients of retroreflection were determined. The encapsulated type reflective sheet with white color shows a coefficient of retroreflection of $210.4cd/1x{\cdot}m^2$, which is higher than the enclosed type ($74cd/1x{\cdot}m^2$). Effect of washing on the reflective property and adhesive power of the reflective sheets was investigated, and it is found that the number of glass beads decreased with washing and the aluminum layer deposited was damaged extensively in the encapsulated lens type reflective sheets.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.57-57
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• 2012

피부염 증상 완화특성을 갖는 힐링섬유소재 제조를 연구하였다. 면소재, 폴리에스테스/나일론 소재에 피부염 증상완화특성이 있다고 알려진 기능성물질을 바인더, 수지 등의 혼합물 페이스트로 만들어 스크린프린팅법을 사용하여 실험을 시도하였다. 제조한 힐링섬유시편소재의 항균특성은 면소재의 경우 99.9% 의 우수한 항균특성을 나타냈다. 암모니아가스의 소취성능은 시간경과에 따라 최대 68%의 소취율을 보였다. 타소재와의 오염견뢰도는 평균 4.5 ~ 5등급, 변퇴세탁견뢰도는 5등급, 마찰견뢰도는 3 ~ 4.5 등급, 일광견뢰도는 5등급을 나타냈다. 의약품 등의 독성시험기준에 따른 힐링소재의 피부자극성을 평가하기 위해 NZW토끼의 피부에 24시간 동안 부착한 후 72시간 동안 사망률, 일반증상, 체중변화 및 피부자극성을 시험한 결과 사망토끼는 관찰되지 않았고, 모든 시험동물에서 특이할 만한 이상증상은 관찰되지 않았다. 체중측정결과 모든 동물에서 정상적인 체중증가를 보였다. 시험소재의 피부자극성을 관찰한 결과 피부자극성이 관찰되지 않아 비자극성(None Irritant)섬유소재로 판단되어 피부염증상완화 특성을 갖는 힐링섬유소재 제조의 실용화 가능성을 연구하였다.

• Tribology and Lubricants
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• v.31 no.3
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• pp.102-108
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• 2015

In this research, we experimentally investigated the sealing performance of elastomeric rotary lip seals for washing machines. In general, NBR is used as a material for elastomeric rotary lip seals in washing machines, but the mixing formula of the rubber material can affect the sealing performance. In this study, we manufactured rotary lip seals using three kinds of NBRs with a different mixing formula, and examined the sealing performance using an acceleration test mode. The results of an SEM investigation into the surfaces of three kinds of specimens showed a much smaller wear volume and better sealing performance for the specimens with smaller particle sizes of mixing composition than for the specimen with the larger. Repeated deformation and recovery by the shaft-to-seal eccentricity on rotation were shown to cause a phase difference in the rubber material, and we measured the recovery ratio to find the influence of this phase difference on the sealing performance. As another method for checking the phase difference, we also measured tan ä, and a lower tan ä was revealed as the recovery ratio increased for each specimen. Specimens with a higher recovery ratio (lower tan ä) were shown to have a better sealing performance. Consequently, specimens with a smaller particle size in the mixing composition had a better sealing performance because they show a higher recovery ratio.

• Fashion & Textile Research Journal
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• v.14 no.1
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• pp.122-129
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• 2012

To develop a waterproof breathable material, we fabricated three kinds of nanofiber web laminates using a massproduced electrospun nanofiber web with different substrates and layer structures. The waterproofness and breathability of nanofiber web laminates were evaluated after repeated launderings and compared with those of conventional waterproof breathable fabrics currently in use, including densely woven fabric, microporous membrane laminated fabric, and coated fabric. The durability of nanofiber web laminates, including adhesion strength, abrasion resistance, tensile strength, and tearing strength, was also assessed and compared with those of conventional waterproof breathable fabrics. The water vapor transmission of nanofiber web laminates increased slightly after repeated launderings, whereas the air permeability somewhat decreased after launderings but still maintained an acceptable level of air permeability. Laundering reduced the resistance to water penetration of nanofiber web laminates, which implies that laminating techniques or substrate materials that could support waterproofness of the laminated structure should be explored. The adhesion strength, abrasion resistance, tensile strength, and tearing strength of nanofiber web laminates were in a range comparable to conventional waterproof breathable materials.

• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.89-100
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• 2019

Sleep apnea, a medical condition associated with a variety of complications, is generally monitored by standard sleep polysomnography, which is expensive and uncomfortable. To overcome these limitations, this study proposes an unconstrained wearable monitoring system with stretch-fiber sensors that integrate with the wearer's clothing. The system allows patients to undergo examinations in a familiar environment while minimizing the occurrence of skin allergies caused by adhesive tools. As smart clothing for adult males with sleep apnea, long-sleeved T-shirts embedding fibrous sensors were developed, enabling real-time monitoring of the patients' breathing rate, oxygen saturation, and airflow as sleep apnea diagnostic indicators. The gauge factor was measured as 20.3 in sample 4. The maximum breathing intake, measured during three large breaths, was 2048 ml. the oxygen saturation was measured before and during breath-holding. The oxygen saturation change was 69.45%, showing a minimum measurable oxygen saturation of 70%. After washing the garment, the gauge factor reduced only to 18.0, confirming the durability of the proposed system. The wearable sleep apnea monitoring smart clothes are readily available in the home and can measure three indicators of sleep apnea: respiration rate, breathing flow and oxygen saturation.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.624-630
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• 1997

Zeolite A helps an increase of detergency performance according to showing the ion exchange effect for polyvalant ions and it's detergency performance could be calculated quantitatively by using the disperse stabilization theory because it is water-insoluble material and is as colloid particles in aqueous solution. In this study, zeta potential of carbon black, cellulose, and Zeolite A were measured in each inorganic salt solutions and applied to the theory of Heterocoagulation in order to evaluate the detergency performance of Zeolite A about the particulate soil at the view point of interaction potential energy. Zeolite A was shown help an increase of detergency performance according to the increasing of the steric repulsion between Zeolite A and cellulose in $Na2CO_3$ solution and the decrease of re-deposition of carbon black on the fabric by rapid coagulation with carbon black in $Na_2SO_4$ solution.

• Fire Science and Engineering
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• v.27 no.5
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• pp.38-43
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• 2013

An automatic spreading fire extinguisher usually installed in a closed area like a boiler room, a laundry store or a restaurant's kitchen room is one of the fire protection equipments. This extinguisher automatically discharges dry powder, extinguishing fire. As this extinguisher has the extinguishing capability applicable to the nominal protection area, objects outside the area cannot be properly extinguished. However only its number is being requested according to the floor area in the related laws, and the extinguishing capability depends on the distance from a fire source. In this study we tried to investigate the extinguishing capability of the automatic spreading fire extinguisher in accordance with horizontal separation distance from a fire source. It appeared that the maximum horizontal separation distance was about 30 cm for both class A and B fire to be certainly extinguished.

• Science of Emotion and Sensibility
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• v.19 no.4
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• pp.83-94
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• 2016

The aim of this study was to investigate effective expression method of performance information of functional clothing and preferred alternatives for the categorized consumer groups according to the perception about the functional outdoor jacket. 472 males and females in their 20s-60s' were surveyed and their answers were analysed and categorized by using SPSS 21.0 statistical program. For the study, four different expression methods for waterproof & breathable fabric, 'illustration only', 'illustration+Korean text', 'illustration+foreign text', and 'chart with Korean text', were presented and asked for finding correct answers. The analysis was done for three categorized consumer groups from the former study, 'unconversant/brand & design pursuing group', 'conversant/function pursuing group' and 'high price/high function preferring group'. The results showed that regardless of groups, 'picture only' was the most preferred method and 'graph' was the least. However, the percentage of correct answers for the 'graph' was the biggest, especially for 'conversant/function pursuing group'. It implied that the effective expression method should be differentiated depending on the target consumer groups. 'Conversant/function pursuing group' more agreed on the need for additional information, such as 'after-washed performance', than other two groups.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.48-48
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• 2011

국내 염색가공업에 종사하는 중소기업은 약 1,700여개 업체로써, 평균 50억/년 매출을 하고 있으며, 생산의 대부분을 임가공에만 의존하고 있는 실정이다. 이들 염색가공업체들은 섬유제품의 품질 향상 등을 위해 전처리, 염색, 가공이라는 섬유습식공정을 행하게 되는데 그 공정이 따로 분리되어 있어 임가공 업체 입장에서는 시간과 비용 차원에서 비효율적인 면이 존재하여 왔다. 따라서 공정합리화, 원가합리화를 위해 따로 분리되어 있는 위 공정을 통합하려는 시도를 많이 했지만 전처리/염색 공정의 통합에서 일부 성과가 있었을 뿐 효과면에서는 아직 미흡한 실정이다. 또한 가공이란 공정은 그사용 약제의 특수성에 따라 기존 Padding-Drying-Curing이라는 3 step process를 반드시 필요로 하고 있기 때문에 가공 공정의 통합은 시도조차 이루어지지 않고 있는 것이 현실이다. 따라서 염색공정과 가공공정의 통합을 시도하기 위해서는 관련 약제 개발이 출발이라 할 수 있으며 그 첫 대상은 염색 공정의 소핑과 가공공정의 유연처리를 동시에 행할 수 있는 소핑유연제로 선정하려 한다. 즉 셀룰로오스계 섬유의 반응성 염색 후 소핑 공정에서 일액형 소핑유연제, 한가지 제품만을 간편하게 사용해도 소핑효과와 유연효과를 동시에 얻어 후속 유연처리 공정을 생략할 수 있는 것이다. 그렇게 되면 시간적으로나 비용적으로 큰 절감 효과를 가져와 임가공 업체의 부담을 덜어 줄 수 있을 뿐만 아니라 공정 통합을 통해 배출되는 폐수의 양도 상당량 감소시킬 수 있을 것으로 기대된다. 본 연구 결과, 폴리옥시에틸렌 트리데실 에테르 타입의 계면활성제와 개질된 디메틸폴리실록산 계열의 실리콘 오일, 그리고 이들의 상용성을 확보하기 위한 특수 용제 및 첨가제를 최적의 비율로 배합하여 안정한 일액형 복합 소핑유연제를 제조할 수 있었다. 제조된 소핑유연제는 유백색 반투명 액상의 외관을 가지며 pH(10%solution)는 $7{\pm}1$, 고형분은 $13.5{\pm}0.5%$이었다. 이 소핑유연제의 성능 평가결과, 소핑력은 기존의 소핑제와 동등 수준으로 세탁견뢰도 4급이상의 성능을 보였고, 유연성 면에서도 기존의 유연제와 동등 수준으로 평가되었다. 이로써 기존의 분리된 소핑 공정과 유연공정을 개발된 제품을 이용하여 통합할 수 있어 염색현장의 비용절감, 공정단축의 효과를 기대할 수 있게 되었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.185-187
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• 2012

In this paper, the MR fluid damper to the application of the paramagnetic (paramagnetic) particles dispersed in the MR fluid inside the magnet current caused by the MR damper using the principles of the internal fluid delivery yield stress variation is characterized in Silky. In other words, the current strength of the MR fluid damper according to the internal friction coefficient varies phenomenon is to use. The MR fluid damper to control the MCU that you want to use Microchip's dsPIC chips, and current control in order to improve performance by using the PWM and UART communication to an external monitor to monitor the entire system was designed. In this study using MR fluid dampers and dsPIC chip dehydration process happens when a washing machine vibration and noise, vibration and noise reduction sikidorok washing machine protection systems are proposed.