comb

The comb is a flat tool with evenly spaced teeth, mounted in the reed or beater of a loom. As the shuttle passes horizontally across the warp, the comb swings forward after each pick to drive the newly inserted weft thread (pick) against the fell, the line where the finished cloth begins. This compaction determines cloth density, weight, and hand.

Industrial looms use steel or wood combs depending on fabric weight and loom speed. Finer fabrics require closer tooth spacing (higher picks per inch) and stiffer combs; heavier goods run faster with wider spacing. The teeth are typically 0.5 to 2 mm thick and spaced from 0.5 to 2 mm apart. Worn or broken teeth create bars and uneven weaving, forcing early replacement. A dull or insufficiently rigid comb fails to seat the pick firmly, leaving soft spots in the cloth and reducing efficiency.

Comb action and timing

The timing and force of the comb strike is critical. It must hit after the weft is laid but before the next shed opens, locking the thread in place. On modern looms, hydraulic or mechanical beating systems control this precisely. Too aggressive a beat breaks delicate filament yarns or stretches elastic fibers; too gentle a beat leaves slack and loose selvages. Operators monitor cloth take-up tension and pick-spacing to keep the comb striking square and flat against the fell.

The comb's geometry also affects selvage formation. Comb teeth at the sides of the shed (the selvage combs) are sometimes angled or spaced differently to prevent curling and ensure clean edge structure. Narrower cloths may run with a single comb; broad goods use multiple combs in tandem or a segmented reed with independent sections.

Comb maintenance is routine but essential. Teeth are filed straight, spacing is checked with go/no-go gauges, and combs are rotated or replaced on a schedule tied to running hours and fabric type. A bent or damaged tooth is almost never repaired in service; the entire comb is swapped out to maintain weave quality and loom efficiency.