Water-Resistance of Nanofiber Textiles

2017 ◽  
Vol 731 ◽  
pp. 55-59
Author(s):  
Martin Černohorský ◽  
Michal Havrlík
Keyword(s):  
Contact Angle ◽  
Water Vapor ◽  
Liquid Water ◽  
Water Resistance ◽  
Diffusion Resistance ◽  
European Standard ◽  
Material Basis ◽  
Nanofiber Textile ◽  
Resistance To Penetration

This work deals with the determination of basic waterproofing properties of nanofiber textiles with basis weights of up to 30 g/m2. Samples used in this experiment were made from nanofiber textiles based on two polymers – PVDF and PUR. Each polymer was prepared in three basis weights. All samples were not treated prior to testing. One of the key properties was the contact angle of water and the resistance to penetration of liquid water. Water-resistance of nanofiber textiles was tested according to the harmonized European standard EN 13859-1., Underlays for discontinuous roofing in pitched roof constructions are tested according to this standard. In the position of underlays there has to be some layer with low diffusion resistance of water vapor and relatively high waterproofing. We suppose such properties of nanofiber textiles. Testing of the two groups of material basis shows correlation between the contact angle and water-resistance of the nanofiber textile.

Diffusion of water vapor through human skin in hot environment and with application of atropine

1959 ◽  
Vol 14 (2) ◽  
pp. 276-278 ◽  
Author(s):  
Konrad J. K. Buettner ◽  
Frederick F. Holmes
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Human Skin ◽  
Liquid Water ◽  
Water Loss ◽  
Diffusion Resistance ◽  
Vapor Transfer ◽  
Hot Environment ◽  
Human Forearm ◽  
Very High

At room temperatures between 20° and 40°C, vapor transfer through skin of human forearm was tested with four small heated bottles containing air of humidities ranging from 2 to 100% relative humidity. Exposure times ranging from 30 to 120 minutes had no influence on results. Water loss or gain of skin were observed for the different bottles. At very high humidities, liquid water deposit on the skin was measured by weighing a blotter. Skin vapor loss decreases systematically when bottle moisture increases. This increase is enhanced at room temperatures above 24℃, where total loss into a dry bottle increases more than fivefold. This increase seems only partially caused by sweat and partially by a decrease of the skin diffusion resistance. Tourniquet and locally applied atropine did not affect vapor transfer in a cool room. In a hot room, the tourniquet lowered the vapor loss by only 20%, whereas atropine drastically curtailed vapor loss. Submitted on August 25, 1958

WATER VAPOR TRANSPORT IN PLASTERS CONTAINING SUPERABSORBENT POLYMERS

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jan Fořt ◽  
Martin Mildner ◽  
Petr Hotěk ◽  
Robert Černý
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Transport Properties ◽  
Building Design ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Diffusion Resistance ◽  
Vapor Diffusion ◽  
Water Vapor Diffusion

A proper characterization of material properties represents an important step towards an efficient building design. Considering the present issues in the construction sector, moisture loads pose a risk not only to increased material deterioration but also to the health of building inhabitants. In this paper, modified plaster mixtures with superabsorbent admixture are designed in order to improve passive moderation of finishing layers against varying humidity conditions. The relationship between the amount of applied superabsorbent admixture and resulting water vapor transport properties is identified and the influence of temperature on water vapor transport is analyzed. The steady-state cup method is used for the determination of water vapor transport properties, namely the water vapor diffusion permeability, water vapor diffusion coefficient and water vapor diffusion resistance factor. The obtained data show temperature as a very significant factor affecting water vapor transport in the analyzed plasters. Considering the dry-cup method arrangement, relative humidity probes should be used for monitoring relative humidity under the sealed sample for a sufficiently precise determination of water vapor pressure gradient.

scholarly journals On the importance of desiccant during the determination of water vapor permeability of permeable insulation material

2020 ◽  
Vol 172 ◽  
pp. 14003
Author(s):  
Thibaut Colinart ◽  
Patrick Glouannec
Keyword(s):  
Water Vapor ◽  
Building Materials ◽  
Wood Fiber ◽  
Construction Materials ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Diffusion Resistance ◽  
Insulation Material ◽  
The Impact

Water vapor permeability of building materials is usually measured using dry cup test according to the ISO 12572 standard. For this test, suitable adsorbing desiccant should be used to provide stable low vapor pressure conditions within the cup and, thus, to ensure the good accuracy of the measurement. In this work, different adsorbing desiccants mentioned in the ISO 12572 standard are tested for measurements performed on wood fiber insulation. For each experiment, relative humidity is monitored inside the dry cup. The results indicate that 0 %RH is not reached inside the dry cup and boundary condition is not always stable for highly permeable construction materials, depending on the adsorbing desiccants. The impact of these observation is evaluated on the determination of water vapor diffusion resistance factor and compared to other sources of uncertainties.

Determination of water content in municipal sludge by multiple headspace extraction gas chromatography

2021 ◽  
Vol 13 (6) ◽  
pp. 796-800
Author(s):  
Ting Zhao ◽  
Zhanbo Hu ◽  
Xin-Sheng Chai ◽  
Yukai Zheng ◽  
Binxin Xu ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Water Vapor ◽  
Water Content ◽  
New Method ◽  
Municipal Sludge ◽  
Headspace Extraction ◽  
Multiple Headspace Extraction ◽  
Sample Vial

This paper reports a new method for the determination of sludge water content by a multiple headspace extraction gas chromatographic (MHE-GC) method. It is based on the water vapor signals in the sample vial from the first five extractions.

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