Cotton Poplin Lot With Excessive Shrinkage and Low GSM
A school-uniform supplier receives 1,200 m of 100% cotton poplin specified at 120 GSM and a maximum 2% shrinkage. Incoming tests on a 50 cm × 50 cm swatch, washed at 60°C and tumble-dried, show warp shrinkage 6.2% and weft shrinkage 3.1%; GSM measures 108. The supplier has already cut 180 trouser panels from the roll before testing, using a pattern with 1 cm seam allowances and a 3 cm hem. The buyer’s delivery date is 18 days away, and the mill says a replacement lot would take 25 days. The cutting room asks whether to continue cutting, and the merchandiser wants to know who bears the cost of remaking. The unit has a 5-thread overlock, single-needle lockstitch line and steam press, but no compressive shrinkage range. The buyer’s specification also requires the fabric to meet the declared GSM after washing.
1. Decide whether to accept, reject or conditionally accept the fabric lot, and justify the decision with the test data and delivery constraints.
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The lot should be held and conditionally rejected, not passed for bulk cutting.
- The shrinkage limit is 2%; the warp result of 6.2% is more than three times the limit, and the weft result of 3.1% also fails. A 100 cm cut leg would finish at about 93.8 cm after the stated wash, so finished measurements cannot be guaranteed.
- GSM is 108 against 120, a 10% shortfall. This points to a thinner fabric with lower tear strength and poorer drape, and it may also mean the mill stretched the fabric to width, which would explain the high shrinkage.
- One 50 × 50 cm swatch is not enough to condemn 1,200 m, but it is enough to stop cutting. I would test at least three specimens from each of 8–10 rolls, conditioned and washed by the same method, and check skew as well as shrinkage.
- A replacement lot takes 25 days against an 18-day delivery, so the practical route is a written deviation: the buyer must accept a relaxed shrinkage limit and the lower GSM, or accept garments made from pre-shrunk fabric with a clear size tolerance. Otherwise reject the lot and negotiate partial delivery or air freight.
- The 180 cut panels should be segregated immediately. Do not cut more until the buyer and mill agree in writing who bears the remake cost.
2. If the buyer insists on the original 2% shrinkage, calculate the cutting allowance for a 100 cm finished leg and explain two practical ways to handle the 180 already-cut panels.
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For the tested fabric, the cut length needed to finish at 100 cm is:
100 ÷ (1 − 0.062) = 106.6 cm, an allowance of about 6.6 cm per leg.
For a fabric that truly meets 2% shrinkage, the cut length would be 100 ÷ 0.98 = 102.0 cm. The difference is about 4.6 cm per leg, which cannot be absorbed by a 3 cm hem. More importantly, a cutting allowance does not change the buyer’s specification: the garment will still shrink 6.2% in the buyer’s wash.
Two ways to handle the 180 cut panels:
- Trial-wash and re-cut only if there is inlay. Overlock the panel edges, wash and dry under controlled conditions, press, then measure. If enough length remains above the hem line, re-cut to the correct size. If not, offer the panels to the buyer as a shorter style or shorts, with written approval.
- Recut from a replacement lot and use the 180 panels as pre-production or test pieces. Do not simply add 6.6 cm to panels that are already cut. Cost the 180 panels against the penalty for late delivery, and disclose any seconds instead of shipping them as first quality.
3. Explain why the single swatch test is weak evidence and what additional checks you would require before a bulk decision.
Read the worked answer
A single 50 × 50 cm swatch taken from one position in one roll cannot represent 1,200 m. Shrinkage varies along a roll, between roll ends, between dye lots and with tension during weaving or finishing. The test also depends on washing machine action, drying method, water temperature and whether the specimen was conditioned before measuring.
Before a bulk decision I would require:
- a sampling plan covering several rolls and both ends of each roll;
- conditioning of specimens before and after washing;
- the same wash and dry cycle repeated for at least three cycles, because cotton can continue to shrink;
- measurement of warp and weft shrinkage, skew, bowing and GSM after washing;
- a check that the test method matches the buyer’s care label and any declared standard;
- a small garment wash trial, because seam puckering and torque may appear only after making up.
The first swatch justifies stopping production, but it does not by itself prove that every roll is unacceptable. The decision should be based on a proper sample, with the lot held in the meantime.