• Title/Summary/Keyword: Vapor permeability

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Moisture and Heat Transfer Characteristics of Waterproof and Water Vapor Permeable Coated Fabrics (기능성 투습방수 코팅포의 수분 및 열전달 특성)

  • Cho, Ji-Hyun;Ryu, Duck-Hwan
    • Korean Journal of Human Ecology
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    • v.8 no.1
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    • pp.151-163
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    • 1999
  • The purpose of this study was to investigate the thermal resistance and the liquid/vapor water transfer characteristics of four waterproof and water vapor permeable coated fabrics with the ground fabric called nylon taffeta. In order to establish the experimental environment, outdoor temperature and humidity in Taegu during the last three years were examined and the experiment was performed at (1) $15^{\circ}C$, 50% R.H., (2) $20^{\circ}C$, 60% R.H., (3) $25^{\circ}C$, 65% R.H., which were the average standards in spring and fall. The test results were as follows ; 1. Among physical parameters, the thinner the thickness was, the higher the water vapor permeability was. But the porosity in thickness was not proportional to water vapor permeability linearly. 2. The thicker the thickness of specimens was and the smaller the bulk density and porosity were, the higher the thermal resistance. And the results also shown that the larger the temperature difference between the environmental temperature and the hot plate was, the more the difference of CLO values was apparent. 3. Since the contact angle of all specimens are above $90^{\circ}$, the all specimens have a good performance in waterproof. The more the specimens surface were rough, the higher the thermal resistance was. 4. According to the result of performing moisture transfer test using the simulating body skin-clothing-environment system, the humidity sensor placed in between the fabric and the environment detected the full saturation in 10 minutes after the experiment had began at $15^{\circ}C$, 50% R.H. and in 15 minutes after the experiment both at $20^{\circ}C$, 60% R.H. and at $25^{\circ}C$, 65% R.H. 5. ${\Delta}$ values of the humidity sensors placed in between the human body and the fabric and in between the fabric and the environment fluctuated repeatedly within the range of $20{\sim}40%$ at $20^{\circ}C$, 60% R.H., and $15{\sim}30%$ at $25^{\circ}C$, 65% R.H.

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Permeability of (SiO2)1-x(ZnO)x Inorganic Composite Thin Films Deposited as a Passivation Layer of Ca Cell (Ca Cell의 보호막으로 증착된 (SiO2)1-x(ZnO)x 무기 혼합 박막들의 투습 특성)

  • Kim, Hwa-Min;Ryu, Sung-Won;Sohn, Sun-Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.3
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    • pp.262-268
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    • 2009
  • We investigated the properties of inorganic diatomic films like silicon oxide ($SiO_2$) and zinc oxide (ZnO) and their composite films are packed as a passivation layer around Ca cells on glass substrates by using an electron-beam evaporation technique and rf-magnetron sputtering method. When these Ca cells are exposed to an ambient atmosphere, the water vapor penetrating through the passivation layers is adsorbed in the Ca cells, resulting in a gradual progress of transparency in the Ca cells, which can be represented by changes of the optical transmittance in the visible range. Compared with the saturation times for the Ca cells to become completely transparent in the atmosphere, the protection effects against permeation of water vapor are estimated for various passivation films. The thin composite films consist of$SiO_2$ and ZnO are found to show a superior protection effect from water vapor permeation compared with diatomic inorganic films like $SiO_2$ and ZnO. Also, this inorganic thin composite films are also found that their protection effect against permeation of water vapor can be significantly enhanced by choosing their suitable composition ratio and deposition method, in addition, the main factors affecting the permeation of water vapor through the oxide films are found to be the polarizability and the packing density.

Soil-Vapor Survey on Soil-Remediation by EMPLEX Collector (EMPLUX Collector에 의한 토양 오염 가스 조사)

  • Kim, Jung-Sung
    • Journal of Environmental Science International
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    • v.17 no.1
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    • pp.119-128
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    • 2008
  • Laboratory analytical results of 22 sets of hydrophobic adsorbent coils containing surface soil-vapor and two soil samples collected by conventional intrusive method from each boring location at two active dry cleaning facilities in the State of Illinois, U.S.A, were presented to evaluate the performance of soil-vapor survey. The most critical factor to determine the effectiveness of soil-vapor survey is the distance from the soil-vapor sampling device to the actual contamination, which is a function of soil porosity, permeability, primary lithology, and other geological and hydrogeological site-specific parameters. Also this factor can be affected by the history of contaminant-generating operations. The laboratory analytical results in this study showed longer dry cleaning operation history (i.e., 50 years) and presence of fine sand at the beneath Site B allow the contaminants to migrate farther and deeper over a fixed time compared to Site A(i.e., 35 years and silty clay) so that the soil-vapor survey is not likely the most effective environmental site investigation method alone for Site B. However, for Site A, the soil-vapor survey successfully screened the site to identify the location reporting the highest soil concentration of chlorinated solvents.

Effect of Water-and Oil-Repellent Finish on Barrier Properties of Nonwoven Fabrics (발수발유가공처리가 부직포의 차단성능에 미치는 영향)

  • Cho, Gilsoo;Choi, Jongmyoung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.4
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    • pp.577-586
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    • 1993
  • Pesticide protective clothing has not been frequently worn due to its lack of thermal comfort. It is important to develop fabrics which can allow the wearer to work in comfort. One of the possible way to achieve the goal is to produce fabrics with a water- and oil-repellent finish which would resist pesticide penetration but maintain some breathability. The purpose of this study were to evaluate the pesticide barrier properties of untreated and water- and oil-repellent finished nonwoven fabrics. Three types of nonwoven fabrics(Tyvek, Sontara and Kimlon) were used as test specimens. By pad-dry-cure method, each of the specimen was treated with fluorocarbon. The pesticide barrier properties (amount of pesticide penetration and residue) were measured by the gas chromatography. The performance properties of untreated and treated specimens were evaluated with respects to water pepellency(KS K 0590), oil repellency(AATCC 118), water resistance(KS K 0591, AATCC 42), water vapor transmission (KS A 1013) and air permeability(KS K 0570). The results of this study were as follows : 1) The untreated Sontara showed much more amount of pesticide penetration than untreated Tyvek and Kimlon, while the treated Sontara showed little amount of pesticide penetration. 2) After laundering, the amount of pesticide residue in the untreated and treated Sontara was less than that in Tyvek and in Kimlon. 3) Water- and oil-repellent finish improved water repellency, oil repellency, and water resistance of specimens. 4) The untreated Sontara and Kimlon showed higher water vapor transmission and air permeability than untreated Tyvek. Water vapor transmission and air permeability of treated specimen decreased compared to those of untreated.

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Effects of processing conditions on water vapor permeability and solubility of Alaska Pollack meal protein isolate film (가공조건이 명태어분단백질 필름의 수증기 투과도와 용해도에 미치는 영향)

  • YOU Byeong-Jin;SHIM Jae-Man
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.413-417
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    • 2000
  • The effects of film processing conditions on the water vapor permeability (WVP), the solubility of film's protein (SFP) and the soluble film's meterials amount (SFMA) were investigated to establish the conditions for preparing biodegradable and edible Alaska Pollack meal protein isolate (APMPI) film. ms of film were decreased with increasing plasticizer concentration but those were decreased with decrement of APMPI's pH values. SEPs were decreased with increasing APMPI's pH and plasticizer concentration. SFMAS were also strongly affected by plasticizer concentration and APMPI's pH. In the case of adding different plasticizers, WVP was increased in order as follows: glycerol, polyethylene glycol and sorbitol but SFMA showed inverse order.

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Preparation of Cellulose-Based Edible Film and its Physical Characteristics (Cellulose를 이용한 가식성(可食性) Film의 제조와 물리적 특성연구)

  • Song, Tae-Hee;Kim, Chul-Jai
    • Korean Journal of Food Science and Technology
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    • v.28 no.1
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    • pp.1-7
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    • 1996
  • Three formulations were used to prepare the cellulose-based edible films consisting of hydrocolloid and lipids; film A made by coating method, films B and C by emulsion method, which were formed in a thin layer glass plate and then dried. Films A, B and C were all approximately 0.03 mm thick with 1-3% moisture, 59-68% lipid, and almost whitish color. Film A was better in tensile strength, and lipids affected water vapor permeability on three films, in which films A and B did not differ significantly. Water vapor permeability of film A did not change but those of films B and C decreased significantly after storage for 8 weeks at $-15^{\circ}C$. Oxygen transmission rate and oxygen permeability of films A and C did not differ and changed significantly after 8-week storage at $-15^{\circ}C$. Under scanning electron microscope (SEM) observation on the structural characteristics of each film, film A indicated relatively uniform and smooth surface coatings of beeswax, while films B and C had individual lipid crystals and could be discerned. As a result, film A was better than films B and C in respect of physical properties, but the selection of useful film depended upon which physical property was more functional. Moreover, it was desirable in some cases for using films B and C because of their easiness of preparation and cold storage durability. It will be further needed to investigate how to formulate films B and C to have more unique surface characteristics, and to reduce water vapor and oxygen transmission rates.

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A study on Physical Properties of Synthetic Leather added Collagen protein (Part I) (Collagen단백질을 첨가한 합성피혁의 물성에 관한 연구(제1보))

  • 백천의
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.6
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    • pp.970-976
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    • 1997
  • Synthetic leather added collagen protein was coagulated in DMF solution. With increasing collagen concentration, thickness of synthetic leather increased. In addition, water vapor permeability and water vapor absoption increased with increasing collagen protein concentration. But MIU and SMD value of surface properties decreased with increasing collagen protein concentration. As a result, synthetic leather added collagen protein showed comfort and dry touch.

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The Effect of Geometrical Structure on the Moisture Transport Properties of Nonwoven Batting Materials (부직포 충전재의 구조적 특성이 수분전달 특성에 미치는 영향-단층구조와 이층구조 부직포의 비교-)

  • 김희숙;나미희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.6
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    • pp.810-818
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    • 2000
  • The purpose of this study was to analyze the effect of geometrical structure on the moisture transport properties of nonwoven batting materials. Two types of nonwovens were used such as single and double layered nonwovens. Steady and dynamic state water vapor transport properties were measured by absorption, evaporation and cobaltous chloride method respectively. The results of this study were as follows: 1) Geometrical structure affected water vapor evaporation, but there were no differences between single and double layered nonwovens in moisture absorption. Thickness and air permeability were influencing factor on water vapor transport rate. 2) Directionality of double layered nonwoven was observed both in steady and dynamic state moisture transport. There were differences between upper and lower layer of double layered nonwoven both in moisture absorption rate and color change by cobaltous chloride method. 3) In dynamic state of water vapor transport rate, single layered nonwoven reached more rapidly at the established relative humidity. It was confirmed that geometrical structure affected water vapor evaporation and hydrophilicity of fiber affected moisture absorption because there were much more water vapor transport rate by evaporation than absorption within the same period of time.

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Performance Investigation of Water Vapor Permeation Using PVA/PSSA-MA Membranes (PVA/PSSA-MA막을 이용한 수증기 투과 성능에 관한 연구)

  • Rhim Ji-Won;Yun Tae-Il;Seo Moo-Young;Cho Hyun-Il;Ha Seong-Yong;Nam Sang-Yong
    • Membrane Journal
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    • v.16 no.2
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    • pp.153-158
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    • 2006
  • The crosslinked poly(vinyl alcohol) (PVA) mwmbranes with poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA) were used to measure the water vapor and air permeabilities at 25 and $35^{\circ}C$. In addition, the contact angles of crosslinked PVA membranes were observed and increased with PSSA-MA contents. The water vapor permeability of 15300 Baller (1 Baller=$10^{-10}cm^3(STP){\cdot}cm/cm^2{\cdot}s{\cdot}cmHg$) was shown the maximum value at $35^{\circ}C$ when PSSA-MA=7 wt% membrane was used. The gas permeability of 146 Barrer was indicated the maximum at PSSA-MA=7 wt% at $35^{\circ}C$ and $P(H_2O)/P(Air)$ was the highest value 109.2 at $25^{\circ}C$.