Canvas
Posted by Nolan (nolans) on Nov 18 2008
Water Penetration Resistance of Woven Fabrics By their very nature, woven fabrics are porous. This can be an advantage because it allows movement of air between internal and external surfaces, thus minimising the likelihood of condensation and temperature differences. However, the obvious difficulty is preventing the penetration of water.
Fabrics are made water repellent by depositing a hydrophobic substance on the fibres, which has the effect of altering their absorption characteristics, thus preventing capillary action or seepage. Water repellant fabrics have open pores and are still permeable to air and water vapour. Water proofing on the other hand entails completely filling the pores with an impermeable substance (usually a coating of polyurethane). Whilst this increases significantly the resistance to water penetration, it also prevents the passage of air and water vapour. Nolaproof canvas and Sunbrella® are water repellant, whereas Sunbrella® “Plus” is water proofed. The main difference between the two processes is degree of resistance to water pressure.
Canvas is a traditional proven outdoor material with a warm, matt appearance. All Nolaproof canvas is woven from a polyester/cotton blend and is rot-proofed. The luxurious-looking acrylic canvas takes its name from its synthetic solution-dyed fibre. “Solution” dyed means that the colour is added during fibre extrusion, which provides a superior colour fastness. Like poly/cotton canvas, woven acrylic canvas is mildew treated.
Back
