Thermal Calender Bonding for Spunbond Fabrics
topic
Spunbond thermal calender bonding uses heated steel rollers with engraved point bonding patterns pressing against smooth or engraved counter rolls at temperatures 10 to 30 degrees Celsius below polymer melting point and nip pressures of 40 to 80 Newtons per millimetre, creating discrete thermal bond points covering 15 to 25 percent of fabric area that provide tensile strength and dimensional stability while maintaining fabric softness and drape in unbonded zones.
Role
Consolidates the spunbond filament web into a coherent fabric through selective thermal bonding at defined point pattern density and coverage that governs the strength-softness trade-off in the finished spunbond, with higher bond area increasing tensile strength while reducing fabric softness and drape, with calender temperature, pressure, and speed being the three primary process variables requiring optimisation for each polymer type and web weight specification.