Solvent-Based Polyurethane Coating

Solvent-based PU coating dissolves polyurethane in DMF or MEK (15–30% solids) and applies via knife-over-roll at speeds of 10–40 m/min, followed by drying at 100–140°C in multi-zone ovens. Film thickness of 20–80 µm is achievable per pass, with multiple passes for heavy-duty applications. Adhesion strength to nylon and polyester substrates exceeds 30 N/5cm. DMF is restricted under REACH (SVoC) requiring closed-loop recovery systems achieving 95–98% solvent recovery. Declining in favor of water-based systems due to regulatory pressure but remains dominant for high-performance military and industrial applications.