In garment manufacturing enterprises, poor fabric quality often affects the quality and delivery of finished products, causing negative impacts on corporate image and customer confidence. For example, denim factories frequently face fabric weft skew problems. If no effective measures are taken during production, garment sizes will be unstable. Deformation and distortion become much worse after washing, usually appearing as fabric twisting, which seriously ruins the appearance and wearability of finished garments.
1. Weft Skew and Weft Skew Rate
Due to improper processing during production, ordinary twill fabrics produce large internal stress and cause weft skew, leading to fabric torsion. Weft skew includes left and right skew.
Weft Skew Degree = (h/H) × 100%.
The higher the weft skew degree, the greater the fabric skew change after washing. The weft skew rate (skew variation rate) reflects the severity of fabric weft skew.
2. Common Testing Methods for Weft Skew Rate
- Draw a 50cm×50cm square 15cm away from the fabric edge.
- Wash the sample, iron it flat after washing, and leave it for 2–3 hours before measurement.
- Measure the diagonal difference (unit: mm).
Formula:
Weft Skew Percentage = 100 × 2 × (Long Diagonal − Short Diagonal) / Sum of the Two Diagonals
Normally, the allowable weft skew range is less than 2%–3%. Excess skew will cause body or leg twisting on garments.
3. Weft Skew Test for Woven Fabrics
Keep the fabric vertical, take a horizontal reference line, align one edge with the line, and measure the height deviation of the other edge. Divide the deviation height by the fabric width to obtain the weft skew value.
A simple field method: tear off a fabric piece, fold it evenly by the edge, measure the maximum offset in cm, and divide by the fabric width to get the skew percentage.
Standards vary by style. Striped fabrics are stricter. Skew below 5% is generally acceptable. If higher, unified bias direction is required during marker layout to prevent tube twisting.
4. Weft Skew Control
Different straighteners are used according to skew types. By mechanical adjustment, the equipment changes the relative running speed of warp yarns, making skewed weft sections advance or lag, so that warp and weft yarns return to a fully perpendicular state across the fabric width.
5. Causes of Weft Skew
Weft skew refers to inclined or S-shaped serpentine distortion of woven and knitted fabrics, mainly caused by two reasons:
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Poor fabric structural design
Improper woven or knitted fabric design will result in inherent weft skew, which requires overall design modification.
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Deformation during dyeing and printing processes
Even with qualified weaving, skew may occur during dyeing and printing. It commonly appears on plain weave staple and filament fabrics processed by rope dyeing and rope washing. Soft fabrics deform more easily, so rope-dyed plain fabrics are prone to severe skew and S-shaped distortion.
Distorted fabric will cause defective finished products after padding, continuous dyeing and printing. Printed patterns will bend obviously. In addition, the adhesive guide belts of rotary and flat screen printers can also induce skew when running with unstraightened fabrics.
6. Solutions to Weft Skew
Ordinary correction method
Fabric passes through skew bars before regulators to create left–right tension difference for partial correction. Many factories install regulators with manual visual correction. However, this method cannot completely eliminate skew.
Complete solution
Manual visual correction has human error risks. The fundamental solution is to install automatic weft straightening machines before regulators or printing machines. Equipped with sensors, microprocessors and precision guiding systems, the device realizes unmanned, accurate correction and thoroughly removes weft skew and serpentine distortion.
Post time: Jul-13-2026