Polymer, mostly polypropylene, is melted and pumped through spinnerets, the filaments are quenched with cooled air and drawn by fast air to about 15 to 35 micrometers, then laid randomly on a perforated belt over suction. A heated point-bonding calender fixes the web. Spunbond is strong, light and cheap, which makes it the base fabric for diapers, gowns, crop covers and SMS composites.
Spunbond at 12 gsm is running clean on both beams, so we can go to the 10 gsm order next.
At very low gsm, coverage comes from finer filaments and even laydown rather than more polymer.
Also heard as
- spunbonded
- SB
- spun-bond
Related terms
Spunlaid
Describes webs made by extruding polymer into filaments and laying them down directly in one continuous line.
SMS
Spunbond-meltblown-spunbond: a three-layer composite of strong spunbond outer layers around a meltblown barrier core.
Point bonding
Calender bonding with an engraved roll that fuses the web only at small, regularly spaced points.
Spinneret
Metal plate drilled with many small holes through which molten polymer is extruded into filaments.
Quench
Stream of cooled, conditioned air that solidifies filaments just below the spinneret in spunbond and fiber spinning.