• Title/Summary/Keyword: leather

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Study on Physical Properties of Synthesized Water-based Tackifier According to Acrylic Monomer Structure and Content (아크릴 단량체 구조 및 조성에 따른 수계 점착부여제의 합성 및 물성 연구)

  • Kim, Se-Jin;Baek, Lan-Ji;Jeong, Boo-Young;Huh, PilHo;Cheon, JungMi;Chun, Jae-Hwan
    • Journal of Adhesion and Interface
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    • v.23 no.2
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    • pp.25-32
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    • 2022
  • There has been a growing demand for water based-type PSA due to environmental regulations for solvent-type PSA. And accordingly, there is a growing expectation as well for tackifiers used to compensate for the problem of deterioration of physical properties. Therefore, In this study, water-based tackifiers were synthesized by changing the contents of hard and functional acrylic monomers CHMA, IBOA, and AA. And these were added to the pressure-sensitive adhesive at 10 phr and their physical properties were compared. Tackiness slightly decreased as CHMA increased and IBOA decreased. Since the intermolecular bonding force increased due to the increase in AA content, the lower the AA content showed better results. Peel strength increased as the tackifiers were added because the fluidity of the polymer chain increased. And higher AA content showed better results because more hydrogen bonds were formed. The holding power tended to decrease as CHMA increased because the content of IBOA relatively decreased which has a large influence on the holding power. And higher AA content showed better results.

Study of Non Pressure and Pressure Foam of Bio-based Polymer Containing Blend (바이오 기반 폴리머가 포함된 블렌드의 상압 및 가압 발포 연구)

  • Dong-Hun Han;Young-Min Kim;Danbi Lee;Seongho Son;Geon-hee Seo;Hanseong Kim
    • Composites Research
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    • v.36 no.5
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    • pp.297-302
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    • 2023
  • There are several methods for shaping foams, but the most commonly used methods involve the use of resin mixed with a foaming agent, which is then foamed under high temperature and pressure in the case of compression foaming, or foamed under high temperature without applying pressure in the case of atmospheric foaming. The polymers used for foaming require design and analysis of optimal foaming conditions in order to achieve foaming under ambient pressure. Environmentally friendly bio-based polymers face challenges when it comes to foaming on their own, which has led to ongoing research in blending them with resins capable of traditional foam production. This study investigates changes in the characteristics of bio-based polymer-EVA blend foams based on variations in the content of bio-based polymers and explores the optimal foaming conditions according to crosslinking. The correlation between foaming characteristics and mechanical properties of the foams was examined. Through this research, we gained insights into how the content of bio-based polymers affects the properties of foams containing bio-based polymers and identified differences between ambient pressure and high-pressure foaming processes. Additionally, the feasibility of commercializing bio-based polymer-EVA composite foams was confirmed.

A Study of Working Environments and Workers Exposed to Chromium (크롬 취급 사업장의 작업환경 및 근로자 폭로 실태에 관한 연구)

  • Yu, Byung-Chul;Son, Byung-Chul;Jun, Jin-Ho;Han, Yong-Soo;Son, Hye-Sook;Lee, Chae-Eun;Jeong, Woon
    • Journal of Preventive Medicine and Public Health
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    • v.27 no.3 s.47
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    • pp.517-530
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    • 1994
  • For the purpose of providing the basic data for health management of workers who are exposed to chromium and for improving the quality of working environment, the authors evaluated blood and urinary level of chromium, the occupational history. AST, ALT, Hb, Hct, nasal specular examinaton on 287 workers who have been dealed chromium compounds in 56 manufacturing Industries of five types, that is, 38 metal plating services(plating),4 manufacture of other fabricated metal products (fabricated metal product), 5 manufacturing of dyestuff(dyestuff), 6 dressing and dyeing of leather(leather), 3 others(manufacture of pottery and ceramic househod wares, motor vehicles, electronic valves and tubes and other electronic components) and also measured the level of chromium in air from February to October 1993. The results were as follows ; 1. The utilized type of chromium compounds was the hexavalent state in plating fabricated metal product dyestuff, leather and the trivalent state in .other, and atmosperic chromium concentration as geometric mean was $0.0138mg/m^3(0.001{\sim}0.068mg/m^3)$ in plating, $0.0115mg/m^3(0.006{\sim}0.015mg/m^3)$ in fabricated matal product, $0.068mg/m^3(0.002{\sim}0.019mg/m^3)$ in dyestuff, $0.0083mg/m^3(0.002{\sim}0.028mg/m^3)$ in leather $0.0039mg/m^3(0.003{\sim}0.005mg/m^3)$ in other by the type of industry and it exceeded TLV-TWA ($0.05mg/m^3$) in five (13.6%) of plating services. 2. The geometric mean of chromium in blood was $1.54{\mu}g/dl(0.10{\sim}3.62{\mu}g/dl)$ in Plantng, $0.94{\mu}g/dl(0.27{\sim}2.82{\mu}g/dl)$ in fabricated metal product, $0.51{\mu}g/dl(0.10{\sim}3.25{\mu}g/dl)$ in dyestuff, $0.87{\mu}g/dl(0.15{\sim}8.00{\mu}g/dl)$ in leather, $0.55{\mu}g/dl(0.20{\sim}2.28{\mu}g/dl)$ in other by the type of industry(p<0.001). 3. The geometric mean of chromium in urine was $14.47{\mu}g/l(6.90{\sim}28.00{\mu}g/l)$ in planting, $4.63{\mu}g/l(0.24{\sim}43.00{\mu}g/l)$ in fabricated metal product, $5.93{\mu}g/l(1.00{\sim}33.00{\mu}g/l)$ in dyestuff, $11.09{\mu}g/l(0.80{\sim}48.00{\mu}g/l)$ in leather, $12.41{\mu}g/l(10.10{\sim}41.00{\mu}g/l)$ in other by the type of industry(p<0.001). 4. As the result of nasal specular examination, twenty four cases (8.4%) of nasal septal perforation among 287 total subjects was observed, and there were 17 (9.7%) cases in plating, 4 csaes (14.3%) in dressing and dyeing of leather. In the comparison of chromium concentration in blood and urine between the perforated group and non-perforated group, the perforated group showed a significantly higher value as $1.883{\pm}3.055{\mu}g/dl\;and\;0.793{\pm}0.815{\mu}g/dl$(P<0.001), $21.31{\pm}34.610{\mu}g/L\;and\;9.304{\pm}11.079{\mu}g/L$ (P<0.001). 5. The mean concentration of chromium in blood, urine and the mean level of AST, ALT, Hb and Hct in exposure group were higher than those of control group(p<0.001).

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A Study on the Correlation Level Among Air Pollution from Solid waste Incinerator (고형폐기물 소각로에서 배출되는 대기오염물질간의 상관성에 관한 연구)

  • 조상원
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.183-187
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    • 1999
  • The purpose of this study is providing basic data to control the air pollutants from solid waste incinerator. Incinerating the waste wood, the electrostatic precipitator had the best collection efficiency. The leather incineration had the same collection efficiency as synthetic resin incineration. And the coarse particle collection efficiency was high. As you know in correlation of leather incineration. pollutants produced a from incinerator are mostly fine particles. If the scrubber used only in the process produced a lot of fine particles. It is adequate to use the above control devices, together with high efficiency collector like bag-filter. To select the adequate control devices, it is required to investigate the size distribution before establishing control devices.

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Manufacture of Soluble Micro-fiber and Low Melting Polymer for Interior Synthetic Leather (인테리어용 인조가죽을 위한 용출형 극세사와 저온 융착사의 제조)

  • Ahn, Young-Moo
    • Korean Journal of Human Ecology
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    • v.12 no.4
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    • pp.529-537
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    • 2003
  • This study was conducted to manufacture the soluble micro-fiber and to synthesize low melting polymer for the interior fabric not to use the polyurethane resin causing some problems. Low melting polyester for weft yarn was introduced by adding 30-40 mol% ratio of isophthalic acid to a main chain of polyethylene terephthalate to decrease the melting temperature up to heat setting temperature. Micro-fiber for warp yarn consisted of both soluble and insoluble components with multi-layered structure. When the soluble micro-fiber was treated by alkaline hydrolysis with 3-5% concentration of NaOH, it showed the turning point at 28% weight loss since soluble polyester was hydrolyzed approximate five times faster than regular polyester.

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Evaluation of Human Sensibility on the Vehicle Seat Cover Fabrics (자동차 좌석커버에 대한 감성평가)

  • 허윤숙;박세진
    • Proceedings of the ESK Conference
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    • 1997.04a
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    • pp.183-189
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    • 1997
  • In order to help develop more comfortable seat cover fabrics, this study primarily surveyed the actual using conditions and the consumers' opinions of the seat cover fabrics. The results of this study were as follows: 1) The colors of seat cover fabric were mostly achromatic. Regarding comsumers' satisfaction on the colors of seat cover fabric, comsumers in their 20's were less satisfied than other age groups. Most unsatisfied consumers prefered bright colors. 2) On the materials of seat cover fabric, synthethic leather and woven were most widely used. Real leather was most prefered due to its luxury and tactile sensation. Woven was secondarily prefered due to its price and tactile sensation. About fourty percent of consumers covered the seat with other cover fabrics because of soil and other reasons. It will be useful if they could choose and change the seat cover fabircs with different materials and colors. 3) When consumers used the seat cover fabrics, the problems that they indicated were not durability and colorfastness but low breathablity during sweating, static electricity, soil, firmness, and cool sensation at the first contact.

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Determination of Trace Metals in Formula Feed by Atomic Absorption Spectrophotometry (원자흡광 분광광도계에 의한 사료중 중김속의 정량)

  • Park, Sung Woo;Lee, Wan Koo
    • Journal of Environmental Health Sciences
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    • v.11 no.2
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    • pp.55-63
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    • 1985
  • The quantities of chrome, lead, iron, copper and manganese in the formula feed were determined by A.A.S. and the results were summarized as follows 1. The content of chromium in the leather and meat meals(SN-2) were 13-66 times as much as the level of permission. 2. In the meantime, lead content in the meat meal (SN-1) was about 20 times as much as permitted level. 3. The iron which is essential constituent of the formula feed was contained in the meat and leather meals and these values were 2-10 times as much as feeding regulations, on the contrary copper and manganese content in the shaving and flesh were below the feeding regulations.

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