ePTFE Membrane Lamination

Expanded PTFE (ePTFE) membranes are produced by stretching sintered PTFE at 200–300% elongation, creating a microporous structure with pore sizes of 0.2–3.0 µm and porosity of 70–85%. Lamination to textile face and liner fabrics uses hot-melt adhesive (15–25 g/m²) or polyurethane tie layers at 120–160°C and nip pressures of 2–5 bar. The resulting 2-layer, 2.5-layer, or 3-layer laminates achieve MVTR of 10,000–25,000 g/m²/24h (ISO 11092) and hydrostatic head >20,000 mm H₂O. Weight adds 40–80 g/m² to base fabric. Premium outdoor apparel applications command $25–80/m² material cost.