• Title, Summary, Keyword: Air permeability

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A Study on the Relationship between the Water Resistance and Air permeability of the Water Resistance Finished Fabrics (시판 방수가공직물의 방수성과 공기투과성과의 상관성에 관한 연구)

  • 김은화
    • Journal of the Korean Home Economics Association
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    • v.20 no.3
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    • pp.19-24
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    • 1982
  • This study was carried out to investigate the relationship between the water resistance and the air permeability. The results are as follows; 1. In case of the water proofing fabrics, We cannot find that there is any relationship between the water resistance and the air permeability according to the kinds of finishing, while in case of the water repellent finished fabries, we can find that there is a correlationship between them, especially the hydrostatic pressure and the air permeability are found to have negative correlation. 2. In case of the water proofing fabrics, the relationship between the water resistance and the air permeability is not affected by the thickness of the fabrics. On the other hand, in case of the water repellent finished fabrics, the relationship between them is affected by the thickness of the fabrics. Especially, the relationship between the hydrostatic pressure and the air permeability as well as the relationship between the water repellency and the air permeability is effect much by the thickness of the fabrics, too. 3. In case of the water proofing fabrics, the relationship between the water resistance and the air permeability is not affected by fabric count. On the otherhand, in case of the water repellent finished fabrics, the relationship between them is affected by the fabric count. Especially, the relationship between hydrostatic pressure and the air permeability, and the relationship between the water proof and the air permeability are affected much by fabric count.

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A Study on the Air Permeability of Composite Nonwovens for Construction (건축용 복합 부직포의 통기성에 관한 연구)

  • 전한용;장경호
    • Textile Science and Engineering
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    • v.35 no.6
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    • pp.344-350
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    • 1998
  • Composite nonwovens were made by thermal bonding method to examine the validity as the construction materials from needle punched and spunbonded nonwovens. The effects of air permeability, number of layers, porosity and pore size on bonding temperatures were investigated. The air permeability of composite nonwovens was varied with the bonding temperatures. The variation of air permeability was dependent on the nonwoven to have more lower air permeability for 2-layer composite nonwovens. Air permeability of composite nonwovens was influenced by the number of layer. In case of the same weight for multi-layered nonwovens, air permeability coefficients were dependent on the porosity and thickness of nonwovens rather than the weight of nonwovens. Finally, the variation of air permeability of composite nonwovens by puncturing was dependent on the pore size rather than the number of puncture.

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A Study on the Air Permeability of Chitosan-treated Fabrics (키토산 가공직물의 공기투과도에 관한 연구)

  • 전동원;이현주
    • Textile Science and Engineering
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    • v.36 no.6
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    • pp.478-488
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    • 1999
  • The chitosan treatment of fabric involves dipping in highly viscous chitosan solution. One of the anticipated drawbacks of the dipping of the fabric samples in highly viscous chitosan solution would be poor air permeability by clogging the pore structures of the sample. There have been no quantitative studies on the changes of air permeability with the treatment conditions. In this study, the effect of molecular weight of chitosan on the air permeability and the effect of chemical nature of fiber materials comprising fabric samples were investigated. Image processing techniques were employed for accurate evaluation of the pore area and the pore size distribution of the fabrics, which could explain the change of air permeability of the chitosan treated fabric samples. The results can be summarized as follows : 1) Chitosan treatment of the fabrics composed of the cellulosic, silk, and wool fibers increased the air permeability, whereas chitosan treatment did not change appreciably the air permeability of PET, nylon, and acrylic fabric samples. 2) High molecular weight chitosan was more effective in improving air permeability than low molecular weight chitosan for the fabrics composed of natural fibers. 3) As chitosan treatment not increases the crispness of the fabric but also improves air permeability for some fabrics, it is a recommendable treatment for fabrics requiring cool touch.

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A Study on the Air Permeability and Water Vapor Permeability of Fiber Assembly Mass (섬유집합체의 통기성과 투습성에 관한 연구)

  • Lee, Deok-Rae;Im, Jin-Mo
    • Textile Science and Engineering
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    • v.34 no.6
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    • pp.343-350
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    • 1997
  • The purpose of this study is to investigate the air permeability and water vapor permeability of polyester (fiber cushions. Those are made by thermal bonding of regular and lowermelting point fiber with blending ratios of 70/30, 60/40, 50/50 wt(%) , and these fiber cushions had different levels of controlled initial specific volume (53.33, 32.00, 22.86, 17.78 ㎤/g) by heattreatment (80, 100, 12$0^{\circ}C$) with constant load. The relationship between air permeability and water vapor permeability of polyester fiber cushions by blending ratios, initial specific volume, heat treatment temperature and thickness was discussed. The results were as follows: The air permeability of fiber cushion was decreased with the increase of the sample thickness, packing density and the amount of low melting fiber, but it was increased slightly with the increase of the heat treated temperature. The air permeability and water vapor permeability of fiber cushions did not depend on the heat treated temperature but the water vapor permeability was decreased with the increase of the blending ratios and initial specific volume, however water vapor transfer resistance was increased slightly.

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Effects of Mordanting, Dyeing, Rinsing, and Fiber Characteristics on the Air-permeability and Color of Fabrics Dyed using Cochineal Dyestuff

  • Na, Ho-Jin;Jeon, Dong-Won;Kim, Jong-Jun
    • Journal of Fashion Business
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    • v.9 no.3
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    • pp.114-124
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    • 2005
  • Based on the previous study, three types at synthetic fibers comprising nylon, PET, and acrylic fibers were investigated in this study. The effect at mordanting on the air-permeability and dyeing properties at fabrics was investigated. The effect at rinsing process on the air-permeability and color was quantitatively investigated by rinsing the mordanted fabric specimens 1$\sim$3 times after mordanting. The air-permeability changed peculiarly according to the characteristics of the tiber materials after mordanting. The air-permeability values of nylon and acrylic fabric specimens dropped significantly after mordanting. On the other hand, those of PET fabric specimens hardly changed after mordanting. The metal ions absorbed on the fibers of nylon and acrylic fabrics did not show the mordanting effect. Regardless of mordanting, cochineal dyestuff made direct links with the molecular chains in nylon fabrics exhibiting dark colors. After dyeing acrylic fabrics, the color did not develop at all, even though partial components of the cochineal dyestuff were absorbed apparently.

Air Permeability of Softwoods Imported from the Russian Far East (북양(北洋) 침엽수재(針葉樹材)의 공기(空氣) 투과성(透過性))

  • Jee, Woo-Kuen;Kim, Gyu-Hyeok
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.4
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    • pp.22-31
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    • 1996
  • Air permeabilities for both sapwood and heartwood of the three softwoods(Picea jezoensis, Larix gmelini, Pinus sylvestris), imported from the Russian Far East, in the three different structural directions were measured using steady-state rotameter method. After measuring permeability, the liquid absorption into the longitudinal permeability specimens was measured, and then related with the measured permeability. The longitudinal permeability was overwhelmingly greater than the transverse permeability, with the radial direction showing higher permeability than the tangential direction. There appear to be species differences in permeability of the three softwoods. The mean longitudinal sapwood permeability of P. jezoensis(3.300darcy) and P. sylvestris(3.028darcy) were considerably greater(ca. 25times) than that of L. gmelini(0.134darcy). Also the average longitudinal heartwood permeability of P. jezoensis(0.300darcy) was about 10 times as great as that of P. sylvestris(0.029darcy) and L. gmelini(0.024darcy). The average calculated radius of pit openings in the heartwood was $0.101{\mu}m$ for L. gmelini, $0.152{\mu}m$ for P. sylvestris for and $0.703{\mu}m$ for P. jezoensis. Heartwood permeability increases with the increase in radius of pit pore and the decrease in ring width and in extractive content, even though the correlation between permeability and its affecting factors was dependent on species. However, there was an inverse relationship between specific gravity and permeability, showing poor correlation between them. The correlation between air permeability and liquid retention was fairly high, so it was revealed that prediction of liquid absorption into the wood by using permeability was feasible.

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Evaluation of Air Void System and Permeability of Latex-Modified Concrete by Image Analysis Method

  • Jeong, Won-Kyong;Yun, Kyong-Ku;Hong, Seung-Ho
    • International Journal of Concrete Structures and Materials
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    • v.19 no.1E
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    • pp.41-48
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    • 2007
  • Addition of latex to concrete is known to increase its durability and permeability. The purpose of this study is to analyze air void systems in latex-modified concretes using a reasonable and objective method of image analysis with such experimental variables as water-cement (w/c) ratios, latex contents (0%, 15%) and cement types (ordinary portland cement (OPC), high-early strength (HES) cement and very-early strength (VES) cement). The results are analyzed by spacing factor, air volume (content) after hardening, air void distribution and structure. Additionally, air void systems and permeability of latex-modified concrete (LMC) are compared by a correlation analysis. The results are as follows. The LMC of the same w/c ratio showed better air entraining (AE) effect than OPC with AE water reducer. The VES-LMC showed that the quantity of entrained air below $100{\mu}m$ increased more than four times. For the case of HES-LMC, microscopic entrained air between the range of 50 to $500{\mu}m$ increased greater than 7 times even in the absence of anti-foamer. Although spacing factor was measured rather low, the permeability of latex-modified concrete was good. It is construed that air void system does not have a considerable effect on the property of latex-modified concrete, but latex film (membrane) has a definite influence on the durability of LMC.

An Experiemtnal Study on the Air Permeability Effect on Concrete Carbonation (콘크리트의 중성화에 영향을 미치는 투기성에 관한 실험적 연구)

  • 권영진;김무한;강석표;유재강
    • Journal of the Korea Concrete Institute
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    • v.13 no.3
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    • pp.277-284
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    • 2001
  • Hardened concrete contains pores of varying types and sizes, and therefore the transport of air through concrete can be considered. The rate of permeability will not only depends on the continuity of pores, but also on the moisture contents in concrete and finishing material on concrete. Also it knows that the durability of reinforced concrete structure is concerned with air permeability which effects on the carbonation occurred by invasion of CO2 gas and the corrosion of steel bar occurred by O$_2$. In this paper, the effects of curing conditions and finishing materials on carbonation and air permeability are investigated according to the accelerated carbonation test. As results, carbonation velocity and air permeability are effected by curing conditions and finishing materials, and air permeability coefficient is effected by moisture content. Also the relationship between carbonation velocity coefficients and air permeability coefficients has been quite well established.

An Experimental Study on the Effect of Curing Condition and Moisture Content Ratio on the Carbonation and Air Permeability of Concrete (양생조건 및 함수율이 콘크리트의 중성화 및 투기성에 미치는 영향에 관한 실험적 연구)

  • 유재강;이강우;강석표;권영진;배기선;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.403-408
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    • 2000
  • Hardened concrete contains pores of varying types and sizes, and therefore the transport of air through concrete can be considered. The rate of permeability will not only depend on the continuity of pores, but also on the moisture contents in concrete. In this paper, the effects of curing conditions and moisture content ratios on the carbonation and air permeability are investigated according to the accelerated carbonation test. The results are follows. 1) Compressive strength, carbonation velocity and air permeability are influenced by the moisture content and curing method. 2) The relationship between carbonation velocity coefficient and air permeability coefficient has been quite well established.

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Effect of Rinsing after Mordanting on the Air-permeability and Dyeing of Fabrics with Cochineal Dyestuff

  • Na, Ho-Jin;Jeon, Dong-Won;Kim, Jong-Jun
    • Journal of Fashion Business
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    • v.8 no.6
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    • pp.137-145
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    • 2004
  • According to the experimental results, it has been reported by several researchers that the air-permeability values of the fabrics mostly decreased by the mordanting during the dyeing procedure. The exact quantitative information, however, has not been presented so far. In this study, the change of the fabric air-permeability was investigated quantitatively. At the same time, the change of the fabric air-permeability according to the dyeing procedure. In order to investigate the possibility of the detachment of the metal ions on the fiber or fabric surface, the change of the air-permeability was investigated after several rinsing of the mordanted fabrics. By comparing the color differences of the cochineal dyed fabrics which were subjected to rinsing procedure after mordanting, the effect of the rinsing of the mordanted fabrics on the dyeing of fabrics was investigated. At the range of mordant concentration, 2% Cu, 2% Sn, 2% Fe, 2% Cr, 5% Al, the metal ions are not excessively absorbed on the fiber surface. Also, any remarkable detachment of the metal ions does not accompany after the mordanting with the subsequent rinsing procedure.