PTFE Membrane Moisture Barriers
topic
Expanded PTFE membrane moisture barriers laminated between nonwoven face and backer layers provide waterproofness exceeding 50000 millimetres hydrostatic pressure, water vapour transmission rates of 3000 to 8000 grams per square metre per day, and steam resistance meeting EN 469 requirements through the micropore structure whose 0.1 to 10 micrometre pores are too small for liquid water penetration but allow water vapour diffusion, with PTFE chemical inertness providing resistance to fire combustion product contamination.
Role
Provides the highest available waterproofness and contamination resistance in firefighter clothing moisture barriers from PTFE's combination of extreme hydrophobicity and chemical resistance, with ePTFE membranes being the dominant moisture barrier technology in premium structural firefighting clothing globally from their proven combination of waterproof protection, breathability, and durability through repeated laundering and long service lives under demanding firefighting conditions.