Fabrics are made of warp and weft yarns that are interlaced at right angles to each other. Ideally, the weft yarns should be perpendicular to the selvages (the edges of the fabric) and form straight lines across the width of the fabric. However, sometimes the weft yarns are displaced from this position and form curves or angles that deviate from the perpendicular line. These are called bowing and skewing defects, respectively. Bowing and skewing defects can affect the appearance, quality, and performance of fabrics and cause problems in sewing, cutting, and draping. Therefore, it is important to understand the causes and prevention of these defects.
What is Bowing?
Bowing is a defect in which the weft yarns form an arc or a wave across the width of the fabric, as shown in the figure below. The degree of bowing is measured by the distance between the highest point of the arc and the perpendicular line, expressed as a percentage of the fabric width.
Bowing can occur due to various reasons, such as:
- Uneven tension or shrinkage of the warp or weft yarns during weaving, dyeing, or finishing.
- Improper alignment or speed of the rollers or nips in the fabric processing machines.
- Inadequate or excessive stretching or relaxation of the fabric during processing or storage.
- Incorrect stitching or splicing of the fabric rolls or batches.
- Fabric design or construction factors, such as yarn count, twist, density, weave, or pattern.
Bowing can be corrected or minimized by:
- Adjusting the tension or shrinkage of the warp or weft yarns before or during weaving, dyeing, or finishing.
- Aligning and synchronizing the rollers or nips in the fabric processing machines.
- Applying appropriate stretching or relaxation of the fabric during processing or storage.
- Ensuring proper stitching or splicing of the fabric rolls or batches.
- Choosing suitable fabric design or construction factors, such as yarn count, twist, density, weave, or pattern.
What is Skewing?
Skewing is a defect in which the weft yarns form an angle with the selvages, as shown in the figure below. The degree of skewing is measured by the angle between the weft yarns and the perpendicular line, expressed in degrees.
Skewing can occur due to various reasons, such as:
- Uneven tension or shrinkage of the warp or weft yarns during weaving, dyeing, or finishing.
- Improper alignment or speed of the rollers or nips in the fabric processing machines.
- Inadequate or excessive stretching or relaxation of the fabric during processing or storage.
- Incorrect stitching or splicing of the fabric rolls or batches.
- Fabric design or construction factors, such as yarn count, twist, density, weave, or pattern.
Skewing can be corrected or minimized by:
- Adjusting the tension or shrinkage of the warp or weft yarns before or during weaving, dyeing, or finishing.
- Aligning and synchronizing the rollers or nips in the fabric processing machines.
- Applying appropriate stretching or relaxation of the fabric during processing or storage.
- Ensuring proper stitching or splicing of the fabric rolls or batches.
- Choosing suitable fabric design or construction factors, such as yarn count, twist, density, weave, or pattern.
Conclusion
Bowing and skewing are common defects in woven fabrics that can affect the appearance, quality, and performance of fabrics and cause problems in sewing, cutting, and draping. They are caused by various factors related to the yarns, the machines, the processes, and the fabric design or construction. They can be avoided or corrected by applying proper measures and techniques at different stages of fabric production and processing. By understanding the difference between bowing and skewing defects, textile engineers and fabric manufacturers can improve the quality and efficiency of their products and services. If you are looking for a reliable woven fabric manufacturer, please contact us.
