Polyurethane Membrane Moisture Barriers
topic
Microporous and monolithic polyurethane membrane moisture barriers for firefighting clothing provide waterproofness of 10000 to 30000 millimetres hydrostatic pressure with water vapour permeability of 2000 to 6000 grams per square metre per day, meeting EN 469 requirements at lower cost than ePTFE systems while providing adequate steam resistance through the combined barrier of the PU membrane laminate construction, with moisture resistance potentially compromised by contamination from fire scene hydrocarbons that swell PU films.
Role
Provides a cost-effective alternative moisture barrier technology for structural firefighting clothing achieving EN 469 compliance at lower material cost than ePTFE while providing adequate waterproofness and breathability for most structural firefighting operations, though with lower contamination resistance and potentially reduced durability compared to chemically inert PTFE systems over the extended service life of professional firefighting clothing.