Polyurethane Foam and Direct Coating Systems
topic
Polyurethane direct coating applies solvent-based or water-based PU dispersions to fabric by knife or gravure methods followed by coagulation in water bath for wet coating or hot air curing for water-based systems, producing porous or dense PU coating films with hydrostatic pressure resistance above 1000 millibars and water vapour transmission rates of 2000 to 8000 grams per square metre per day for waterproof breathable fabric production.
Role
Produces the primary waterproof breathable fabric construction for outdoor performance apparel through the controlled porous PU coating that prevents liquid water ingress from hydrostatic pressure while allowing water vapour diffusion for breathability, with coating porosity control through coagulation conditions determining the permeability balance between waterproof and breathable performance required for different outdoor activity intensities.