Calculating Essential Greige Warp Set Parameters for Shuttleless Weaving
Greige warp parameters require calculating loom reed width from finished dimensions while incorporating weave crimp, size pick-up, and shuttleless selvedge waste.
Tuck-in Selvedge Space
Clearing Margin
Lateral clearing margins along the fabric edges accommodate the mechanical components that fold cut weft ends back into the shed. The width of the tuck-in selvedge space is determined by the size of the tucking needle and the thickness of the yarn being woven. This margin must be planned during loom set-up to avoid collisions between the reed and the tucking head.
Mechanism Action
During the weaving cycle, a mechanical nozzle or needle grips the cut end of the weft and tucks it into the next shed before the reed beats up. Having a proper tuck-in selvedge space allows the tucking device to operate without touching the main body of the warp yarn. This action creates a strong, clean border.
Fabric Quality
An inadequate tuck-in selvedge space can lead to loose weft ends that project from the fabric, which can cause snagging during subsequent processing.
Speed Constraint
Rapid mechanism actions require a brief fraction of the loom cycle to complete. Because the tuck-in selvedge space must be cleared before the next pick is inserted, the speed of the loom is limited by the action of the tucking device. Newer pneumatic tucking systems require less space and allow for faster loom speeds.