PUR hot melts are mass-produced PUR prepolymers with reactive terminal groups, which when exposed to air humidity and/or paper humidity after application, undergo a cross-linking reaction. The prepolymers wet out and penetrate paper well, contributing to high adhesion and thus high page pulls.
After cross-linkage, PUR films show a high inherent strength (cohesion), resulting in extremely durable adhesive films. Not only are these films insensitive to printing ink oil and solvents, they also provide good aging resistance.
If you bind brochures with PUR hot melt, you can expect extreme cold and heat resistance. PUR bondings stick safely at temperatures to 120C without quality loss, and remain elastic even at minus 40C.