Analysis of Causes and Solutions for Common Fabric Problems- Analysis of Causes and Solutions for Fabric Weft Skewness

 ------What is weft skew Weft skew means the horizontal weft yarns of the fabric are not perpendicular to the fabric selvedge, appearing slanted, curved or twisted. Garments made from skewed fabric will have crooked hems, twisted trouser legs, left-right asymmetry, and misaligned stripes & checks.  

------Three common types of weft skew (search keywords for real pictures)

① Linear weft skew The whole weft of the fabric slants evenly to one side in a straight diagonal line.  

② Crescent curved weft skew The fabric center is straight while both sides bend like a crescent arc.

③ Spiral twist skew (common in knits) Fabric edges are twisted and the fabric surface spirals easily, causing twisted hems and trouser legs after cutting.

------Causes of weft skew  

1) Weaving process

1. Unbalanced left and right warp tension on the loom, pulling weft yarns slanted.

2. Worn reed and heddle parts lead to uneven beating-up force.

3. Uneven tension of the take-up roller (one side tight, one side loose).

4. Uneven yarn twist and thickness difference cause skew after natural shrinkage.  

2) Dyeing and finishing (main cause)

1. Unbalanced left-right tension during desizing, scouring and bleaching.

2. Unbalanced left-right overfeed on stenter; unsynchronized pin clip chains.

3. Uneven oven temperature and air volume, causing inconsistent drying and shrinkage on both sides.

4. Uneven padding roller pressure leads to different stretching degree on left and right.  

3) Fabric inherent characteristics

1. Knitted fabrics (jersey, rib, interlock): coil structure is prone to spiral twist skew.

2.  Spandex stretch fabrics: uneven resilience easily causes weft skew.

3. Lightweight soft fabrics (rayon, chiffon): easy to skew under slight tension.

4. Striped, checked and printed fabrics: slight skew will cause obvious pattern misalignment.  

4) Storage & manual operation

1. Fabric roll and stack pressure cause deformation.

2. Unilateral forced pulling during fabric opening, rewinding and spreading.

3. Forced alignment at cutting table artificially aggravates weft skew.  

------Complete solutions  

1) Fundamental improvement at fabric mill

1. All grey fabric must pass photoelectric weft straightener for automatic correction.

2. Adjust stenter machine: balance left-right temperature, air volume and overfeed; adopt relaxation setting without over-stretching.

3. Calibrate loom warp tension, replace worn accessories; produce with same batch and lot.  

2) Incoming fabric pretreatment

1. Let fabric relax for 24 hours to release internal stress.

2. Steam pre-shrinking to eliminate shrinkage and deformation in advance.

3. Inspect weft skew roll by roll; isolate unqualified rolls and forbid normal cutting.  

3) Remedies at cutting room

1. Minor skew: gently pull diagonally in reverse direction, set with steam iron then cool down.

2. For stripe/check/print fabric: do not align by selvedge only; layout along straight weft line for pattern matching.

3.  Severe skew: downgrade for lining and small accessories only, not for tops and trousers.

4. Spread fabric naturally; avoid forced pulling.  

4) Remedy for finished garments

1. Overall steam pressing, reshape in reverse direction then cool setting.

2. Re-sew side seams and hems for seriously twisted garments.

3. Scrap uncorrectable fabric to avoid customer complaints and returns.  

------Simple weft skew standard (workshop use)  Calculation formula Weft Skew % = (Skew deviation ÷ Fabric width) × 100% Example: Fabric width 150 cm, deviation 3 cm Skew = 2.0% (exceeds standard, not allowed for cutting)  Allowable tolerance - Normal woven fabric: ≤1.0% - Stripe / check / printed fabric: ≤0.5% - Knitted & stretch fabric: ≤1.5%