water vapor permeability

water vapor permeability

That property of a material which permits the passage of water vapor through it; the time rate of water vapor transmission through a unit area of flat material of unit thickness induced by a unit vapor pressure difference between two specific surfaces, under specified temperature and humidity conditions.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
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Key players in the starch based edible coatings market have also been working on the incorporation of fatty acids into corn starch based variants, to ebb their hygroscopic nature and improve water vapor permeability. The Fact.MR study opines that key demand determinants for starch based edible coatings are prevailing restrictions on the use of agrochemicals, and the shift in consumer preference toward high-quality, minimally processed fresh foods, and vegetable products.
low moisture and water vapor permeability, and excellent chemical resistance against polar solvents and solutions including acids, bases, esters, and alcohols but only moderate heat resistance and poor chemical resistance against nonpolar solvents like alkanes, ethers, and oils.
The water vapor and oxygen permeability of these films increased slightly in the loading range below 0.5%, but increased dramatically in the films of LMA2 and LMA4 as compared with the control samples, with the water vapor permeability increased approximately three and five fold, respectively.
The oil in the cedar effectively blocked the Tyvek water vapor permeability and most of his sheathing rotted from water vapor coming from inside his house.
The color, thickness, and water vapor permeability (WVP) variables for each film formulation are given in Table 1.
Water Vapor Permeability. WVP of 5-CA films was 8.33 g x [cm.sup.-1] x [s.sup.-1] x [Pa.sup.-1] which had the highest value compared to all films as shown in Figure 6(a).
Specifically, the puncture strength and deformation, tensile strength and percentage tensile elongation, water vapor permeability and opacity of the films were measured by the researchers.
Membrane characterization by SEM, water vapor permeability and intrusion pressure were carried out using the elaborated LDPE membranes, showing the influence of the polymer content in the pore size, which affects the performance of the membrane, such as permeability and water intrusion pressure.
Water Vapor Permeability. Figure 6 shows water vapor transmission rates of all denatured specimen (cast films).
Table III.-Moisture content, percentage moisture uptake at 84% RH, water vapor transmission rate and water vapor permeability results of matrix type transdermal patch of Bisoprolol fumarate.
It discusses various types of polymers for food packaging and polymer nanocomposites and antimicrobial activity, oxygen absorbers (scavengers), ultraviolet blocking, and water vapor permeability. ([umlaut] Ringgold, Inc., Portland, OR)