Weaving Operations and Production Control
This domain tests production planning, loom allocation, efficiency measurement and material consumption in the weaving shed.
Core rules
- Loom efficiency = actual picks or metres produced divided by theoretical production at rated speed. It excludes or includes stoppages according to the defined basis, so state the basis.
- OEE = availability × performance × quality. It separates stoppage losses from speed losses and defect losses.
- Production planning balances loom capacity, style, beam plan, weft supply and delivery date. Style changes consume time and generate waste.
- Weft consumption per metre depends on fabric width, picks per metre, weft count and crimp. Warp consumption depends on end count, warp count, length and crimp.
- Waste includes loom waste, beam remnants, cut selvedges, defect cuts and sample lengths. It must be measured, not estimated.
- Pick density and reed width determine weft usage; wider fabric uses more weft per pick.
Worked example
Fabric width 120 cm, 50 picks/cm, 20 tex weft, weft crimp 5%. Picks per metre = 50 × 100 = 5,000. Weft length per metre of fabric = 1.20 × 5,000 × 1.05 = 6,300 m. Weft mass = 6,300 × 20 / 1000 = 126 g per metre.
Traps
- Using picks per inch as picks per cm.
- Omitting crimp and selvedge allowance.
- Quoting efficiency without defining the time basis.
- Confusing OEE with loom efficiency alone.
- Planning capacity at rated speed instead of effective production.