Reactive Polyurethane Hot Melt Lamination

Reactive polyurethane hot melts (HMPUR) are moisture-curing NCO-terminated prepolymers applied at 80–120°C melt viscosity (5,000–50,000 mPa·s) via slot die or gravure at 20–50 g/m². Initial green strength of 5–15 N/5cm develops within 30–60 seconds of application. Full cure peel strength of 60–120 N/5cm is achieved within 24–72 hours as NCO groups react with ambient moisture. Operating pot life of 3–8 hours at application temperature. Heat resistance of cured bond exceeds 120°C versus 60–70°C for conventional hot melts. Used for shoe upper assembly, automotive airbag covers, and performance sportswear bonded seams replacing stitching.