Water penetration resistance

BS. 546, Coated fabrics for use in the manufacture of water penetration resistant clothing. Part 4, 1991,... 

BS - 546. Coated fabrics for use in the manufacture of water penetration resistant clothing Part 2. Specification for non water vapour permeable coated fabrics, 1993. Part 4. Specification for water vapour permeable coated fabrics. 1991. Part 5. Specification for coated fabrics for immersion suits. 1995. 

Bakken G, Banta M, Higginbotham C, Lynott A. (2006) Its just ducky to be clean The water repellency and water penetration resistance of swimming mallard Anas platyrhyn-chos ducklings.Biol 37 561-571. 

Water Repellency and Water Resistance. Water repeUency is defined as the abihty of a textile fiber, yam, or fabric to resist wetting, whereas water resistance is a general term appHed to a fabric s abiUty to resist wetting and penetration by water (2). A third term, waterproof, is appHed to those fabrics that do not allow any water penetration at all. Waterproof fabrics are generally coated with an impermeable surface layer that does not allow air permeabihty. Water-repellent finishes are hydrophobic compounds that are appHed to fabrics to inhibit water penetration while still allowing air permeabihty. 

Water resistance test methods include AATCC 127 (hydrostatic pressure test), AATCC 42 (impact penetration test), and AATCC 35 (rain test). In the hydrostatic pressure test, a sample is subjected to a column of increasing water pressure until leakage occurs. The impact penetration test requires water to be sprayed on the taut surface of a fabric sample from a height of two feet. The fabric is backed by a blotter of predeterrnined weight, which is reweighed after water penetration. The rain test is similar in principle to the impact penetration test. 

Water-resistant fabrics protect against water penetration during a light or brief shower and pass AATCC Test Methods 22 and 42 (Impact Penetration Test). 

For dynamic water resistance, the BaUy Penetrometer Test, lUP/10 (52) measures water penetration. 

For dynamic water resistance, the Maeser Test, ASTM D2099 (53) measures the number of flexes and water penetration. The flex imparted to the leather is a magnification of the flex given the vamp of a shoe ia actual wear. 

Cured resins have excellent chemical resistance. This is probably because, although the resins have some reactive groupings, most of the reactions occurring do not result in the disintegration of the polymer molecules. Therefore, whilst surface layers of molecules may have undergone modification they effectively shield the molecules forming the mass of the resin. The resins have very good resistance to water penetration. 

This task represents a continuation of efforts to maximize the hydrophobicity of acrylic, epoxy, and other polymeric systems for resistance to water penetration and environmental degradation, and to minimize the dielectric constant and improve the processability for adhesives and coatings, without compromising the necessary structural characteristics for materials used for, e.g., structural elements, liners, paints, and microelectronic devices. 

Internal sizing may be carried out over a wide pH range, but it is popular now to use neutral or slightly alkaline systems. When successfully performed, it retards the rate of penetration of a fluid through capillaries formed both within and between fibres. The fluid involved is, for most commercial grades of paper, water but resistance to non-aqueous fluids may also be important in some applications. This discussion will concern itself only with sizing against aqueous systems. 

CRS which had been phosphated prior to bonding exhibited a significant enhancement of durability and corrosion resistance under the same accelerated conditions (Figure 4). The crystalline barrier layer restricted the exposure of the metal oxide to moisture by reducing the rate of water penetration at the interface. Even samples exposed to the cycle test were able to maintain failure within the adhesive for up to 10 days, after which varying amounts of interfacial failure were noted. Again, room temperature control samples maintained initial joint strength and failure remained cohesive within the adhesive. 

The layer of soft-ice adjacent to an interface may be melted or disoriented by adding LiCl. By this means Blank 2) has shown that the value of E/ of a monolayer of octadecanol to the passage of CO2 could be reduced from about 300 sec. cm. for pure water to only about 30 sec. cm. for 8M LiCl solution. Under the latter conditions we believe that the soft-ice is apparently almost completely melted. A small amount of methanol in the water penetrates and somewhat disrupts the film of octadecanol, and Ri again drops from 300 sec. cm. to about 30 sec. cm. i, though with further increase in the methanol concentration the resistance increases again to about 500 sec. cm., presumably due to the methanol molecules held in or near the surface increasing the viscosity of the soft-ice layer. These interpretations of the experimental data are not those proposed by Blank, and further studies with a viscous-traction surface-viscometer (1) should certainly be carried out to test this soft-ice theory. 

Exemplary materials for the waterproofing of masonry surfaces are waterproof membranes such as poly(vinyl chloride), PE, butyl rubber, and sealants such as tar, asphalt, paints, poly(urethane), epoxy or mastics. While these waterproofing agents can offer excellent resistance to water penetration and other contaminants, they can alter the appearance of the masonry surface, e.g., they may change the color of the surface or leave it with a shine. Waterproofing treatments can also trap moisture within the masonry surface and promote spalling. 

Following are the tests described in this Spec wet tensile strength, adhesion at low temp, moisture-vapor transmission rate, water-penetration rate corrosion, accelerated aging, dry tensile strength and tearing resistance... 

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