Poplin order short in width, EPI and GSM
A powerloom unit in Salem accepts an order for 5,000 m of grey cotton poplin: 40s warp x 40s weft, 110 ends per inch, 76 picks per inch, 44-inch finished width and 120 gsm. The contract states 8% warp shrinkage and 3% weft shrinkage from greige to finished. The loom has 56 inches of reed space. The unit uses a 52s reed with 2 ends per dent and a 70-pick change wheel. After 600 m, the buyer's inspection reports 42.5-inch width, 104 ends per inch, 70 picks per inch and 108 gsm. The production manager says the loom was already set with a 4,800-end warp beam, and re-beaming would stop delivery for three days. The buyer rejects the 600 m and threatens cancellation. The unit has 4,200 m of the same warp left and four looms that could run the order.
1. Calculate the ends and reed count required by the specification, and diagnose the shortfall in width and GSM.
Read the worked answer
Required ends = 110 ends/in x 44 in = 4,840 ends. At 3% weft shrinkage, greige width = 44 / 0.97 = 45.36 in. With 2 ends per dent, required reed count = 4,840 / (2 x 45.36) = 53.4, so a 54s reed is needed, not 52s. Actual ends on the cloth = 104 x 42.5 = 4,420 ends. That is 420 ends short of specification and 380 short of the 4,800-end beam, so ends were missing or not drawn in. The 52s reed also lowers EPI, and the 70-pick wheel lowers PPI. The GSM follows EPI and PPI: (104/40 + 70/40) = 4.35 against (110/40 + 76/40) = 4.65, about 6.5% lower, which matches 108 gsm against 120 gsm. Width loss is mainly from missing ends, not from the 56-inch reed space.
2. Should the unit re-beam the remaining 4,200 m or negotiate? Show the commercial and technical reasoning.
Read the worked answer
First stop the loom and correct the easily correctable faults: draw in the missing ends from the 4,800-end beam, change to the correct reed if the beam width permits, and set 76 picks. But the beam itself is 40 ends short of the 4,840 required. At a finished width of about 44.8 in, 4,800 ends give only about 107 EPI, still below 110. Therefore the choice is either a written tolerance for about 107 EPI and 112-114 gsm with a price adjustment, or re-beaming 4,840 ends. Re-beaming costs three days across four looms and risks the delivery penalty; shipping reject fabric costs the buyer's confidence and the repeat order. Calculate the penalty and the lost contribution before deciding. The 600 m already rejected should not be shipped as poplin; sell it as second quality or use it for samples. Do not rely on the 56-inch reed space as the cause, because width is controlled by ends and reed, not by available loom width.
3. What inspection plan would you set for the balance of the order?
Read the worked answer
Check the warp beam count before drawing in, verify reed count and picks per inch against the contract, and measure width, EPI, PPI and GSM at the start of each loom and then every 500 m. Record the reed, pick wheel and beam number against each piece. Inspect for missing ends, reed marks and starting marks. Hold the first 100 m for buyer approval before running the balance. If any result is outside the agreed tolerance, stop that loom rather than continue and sort later. This plan catches the error at the loom, where it is cheap to correct, instead of at the buyer's table, where it becomes a claim.