Written by Shatarupa Majumdar
Fabric manufacturers aim to manufacture quality fabrics and maintain certain quality standards. Out of many fabric defects, two major defects are bowing and skewing. In this article, you will learn about these two fabric defects. Later the evaluation process of these two defects is shown with the calculation formula.
Bowing and skewing are defects that are created when there is a distortion in weft laid across the whole width of the fabric. These faults are very critical for fabric.
When the weft yarn in the fabric gets displaced from a line perpendicular to the fabric selvedge is called bowing. This weft displacement forms one or more arcs across the width of the fabric. Bowing can be called a defect but in the case of some woven patterns (2/2 Twills), bowing is being introduced (During fabric processing) in fabric to avoid residual bowing in the final finished fabric.
Related post: Classifications of fabric defects
Nowadays woven fabrics are being produced on high-speed shuttle looms, where fabric selvedge at both ends is being held by temples having sharp pins impregnated in fabric. This in turn prevents fabric to roll back post beating action due to let off motion force. During take-up action when the fabric is being pulled the application of force is more at center of fabric, and less at selvedge due to temple hold. And bowing of 1 inch to 1.5 inches is being generated in fabric at both selvedge ends. This is called Residual Bowing in greige fabric.
Figure 1: Bowing in fabric.
Figure 2: Skewing defect in fabric
Bowing (%) = (D/W) x 100
D – Maximum bow in the fabric (inches)
W – Fabric width (inches)
Example:
In the next step, the fabric is laid on the fabric inspection table.
Bowing and skewing can be caused by uneven tension across the fabric width during dyeing or finishing processes. Improper stretching during scouring, dyeing, or finishing might also cause bowing or skewing in the finished fabrics.
Correcting the tension settings on processing machines should rectify these defects.
Related post: How to Check the Spirality of Fabric?
Fabric manufacturers aim to manufacture quality fabrics and maintain certain quality standards. Out of many fabric defects, two major defects are bowing and skewing. In this article, you will learn about these two fabric defects. Later the evaluation process of these two defects is shown with the calculation formula.
Bowing and skewing are defects that are created when there is a distortion in weft laid across the whole width of the fabric. These faults are very critical for fabric.
What is Bowing in fabric?
Bowing is a fabric defect.When the weft yarn in the fabric gets displaced from a line perpendicular to the fabric selvedge is called bowing. This weft displacement forms one or more arcs across the width of the fabric. Bowing can be called a defect but in the case of some woven patterns (2/2 Twills), bowing is being introduced (During fabric processing) in fabric to avoid residual bowing in the final finished fabric.
What is skewing in fabric?
Skew or skewing is a common fabric defect in woven fabrications where weft or filling yarns are distorted means pattern on one side of the fabric is ahead or behind the pattern on the opposite side. This is usually caused in fabric weaving or processing when both fabric edges are pushed by a roller with different forces. So due to the difference in force at each edge causes the movement of weft pattern.Related post: Classifications of fabric defects
Formation of the defects
Bowing formation at the weaving stage:Nowadays woven fabrics are being produced on high-speed shuttle looms, where fabric selvedge at both ends is being held by temples having sharp pins impregnated in fabric. This in turn prevents fabric to roll back post beating action due to let off motion force. During take-up action when the fabric is being pulled the application of force is more at center of fabric, and less at selvedge due to temple hold. And bowing of 1 inch to 1.5 inches is being generated in fabric at both selvedge ends. This is called Residual Bowing in greige fabric.
Figure 1: Bowing in fabric.
Figure 2: Skewing defect in fabric
The testing procedure for bowing defects:
- The entire roll of the fabric is taken after removing the first one-metre length. Three test areas for test specimens are selected from each fabric roll.
- In the next step, the fabric is laid on the fabric inspection table.
- The actual path of the weft yarn across the width is traced.
- The maximum difference between the actual yarn path and the perpendicular path is measured.
- If there is more than one bow in the fabric, all the instances are measured. The greatest value of path deviation is considered in the calculation.
Calculations of bowing:
The following formula is used in calculating the bowing percentage in fabric. Bowing (%) = (D/W) x 100
D – Maximum bow in the fabric (inches)
W – Fabric width (inches)
Example:
The testing procedure of skewing:
The entire roll of the fabric is taken after removing the first one-metre length. Three test areas for test specimens are selected from each fabric roll.In the next step, the fabric is laid on the fabric inspection table.
The actual path of the weft yarn across the width is traced.
The maximum difference between the actual yarn path and the perpendicular path is measured.
Calculations of Skewing:
The following formula is used in calculating the skewing percentage in fabric.
Skewing (%) = (D/W) x100
D – Difference between the actual and perpendicular path of the weft yarn (inches)
W – Fabric width (inches)
Calculations of Skewing:
The following formula is used in calculating the skewing percentage in fabric.
Skewing (%) = (D/W) x100
D – Difference between the actual and perpendicular path of the weft yarn (inches)
W – Fabric width (inches)
Conclusion
Fabric defects such as bowing and skewing cause defects in garments made of defective fabrics. Fabric mills need to take care to avoid bowing or skewing defect formation in the woven fabrics during fabric manufacturing and processing. On the other hand, garment manufacturers should consider checking these two fabric defects with other fabric quality parameters.Bowing and skewing can be caused by uneven tension across the fabric width during dyeing or finishing processes. Improper stretching during scouring, dyeing, or finishing might also cause bowing or skewing in the finished fabrics.
Correcting the tension settings on processing machines should rectify these defects.
Related post: How to Check the Spirality of Fabric?
References:
https://www.textileadvisor.com/2020/04/testing-of-bowing-or- skewinginfabric.html.
https://www.intouch-quality.com/blog/5-common-fabric-defects-prevent
https://www.textileadvisor.com/2020/04/testing-of-bowing-or-skewing-in- fabric.html
https://textilelearner.net/bowing-and-skewing-defects-of-fabric/
https://www.textileadvisor.com/2020/04/testing-of-bowing-or- skewinginfabric.html.
https://www.intouch-quality.com/blog/5-common-fabric-defects-prevent
https://www.textileadvisor.com/2020/04/testing-of-bowing-or-skewing-in- fabric.html
https://textilelearner.net/bowing-and-skewing-defects-of-fabric/
About the Author: Shatarupa Majumdar is an avid learner and aspiring professional in the realm of textile technology. She is committed to contribute innovative solutions and pushing the boundaries of this ever-evolving industry. With a profound interest in the intricate world of textiles, she is dedicated to explore the diverse facets of this field, aiming to combine technological advancements with creativity.