The web runs between two heated steel rolls, usually one engraved with a pattern and one smooth, so fibers fuse under combined heat and pressure. Smooth-on-smooth area bonding gives a thin, flat, stiffer fabric, while engraved point bonding leaves most of the web free for softness and drape. Roll temperature, nip load and line speed have to be balanced across the full width.
Calender bonding looks clean, oil is 148 on the pattern roll and 145 on the anvil.
Calender roll edges tend to run cooler than the center, so check bond strength across the full width, not just mid-web.
Also heard as
- thermal calendering
- calendering
- hot calender bonding
Related terms
Point bonding
Calender bonding with an engraved roll that fuses the web only at small, regularly spaced points.
Bond area
Percentage of a point-bonded fabric's surface covered by fused bond points.
Thermal bonding
Bonding a web by heating it so thermoplastic fibers or binder fibers soften and fuse at their crossing points.
Spunbond
Nonwoven of continuous filaments extruded, air-drawn and laid on a belt, then usually bonded by a hot calender.