Defects during sewing a product is a common phenomenon in a Sewing Industry especially in a garment manufacturing industry. A garment industry should always be prepared to deal with sewing defects to avoid rejections.
During my days in export industry while working in R&D department, I had seen many such cases where we always had to diagnose a garment to provide their quick remedies. Hence, a garment Industry should always be prepared to deal with sewing defects to avoid rejections and to build trust among its buyers.
Someone can refer the following quick guide to understand the most common sewing defects, causes and what can be done to correct them:
Needle damage
- Causes holes, picked threads, ruptured threads or other damages to the fabric.
- Caused by wrong size or type of needle, blunt needle, needle point damaged, needle heat or machine needle feeding.
- Can be remedied by changing the needle or adjusting the feed mechanism.
?Feed Damage
- Causes damage on the fabric surface or on seam.
- Caused by incorrect type of teeth, excessive pressure by foot, improper alignment of feed dog and presser foot, damaged throat plate or excessive machine speed.
- ?Remedied by adjusting the feed dog teeth, pressure of the foot, or changing the damaged throat plate.
Skipped stitches
- Causes excessively long stitches of two or more stitch lengths during the stitch cycle
- Caused by the hook irregularly failing to pick up the loop of thread from the needle’s eye.
- Can be remedied by adjusting the type of needle, length of needle, bobbin hook position, matching thread to needle.
?Thread breaks
- Caused by too thick a thread for the needle, too thin a thread for the needle, needle heat, operator working unrhythmically or tight tensions
- Remedied by adjusting the correct thread size to needle size, adjusting the machine tension, operator training and using a treated thread to counter needle heat.
?Broken stitches
- Cause unseemly seam appearance and less strength of the seam
- Caused by wrong stitch type, too tight tensions, a badly formed joint in the seam where the second line of stitches run over the first and crack it, sharp feeds and too great a pressure
- Can be remedied by adjusting the feed dog position and pressure, adjusting the tension, selecting the correct stitch type for the seam.
?Seam grin
- Causes the seam stitch line to be seen and seam to open up when pressure is applied
- Caused by too loose a tension or too large a stitch length or the wrong type of stitch.
- Can be remedied by adjusting the stitch density, stitch tension or the stitch type.
?Seam pucker
- Causes the seam to appear wrinkled
- Caused by differential fabric stretch, differential fabric dimensional instability, due to extension in sewing thread, due to sewing thread shrinkage, due to structural jamming, due to mismatched patterns
- Remedied by using special feed systems, using dimensionally stable fabric, adjusting tension settings or changing thread type, matching performance of thread to fabric, fabric design change or sewing at bias and proper cutting respectively.
?Staggered stitches
- Causes poor appearance of the seam
- Caused by yarns in the fabric deflecting needle away from the straight line of stitching, faulty feed motion, incorrect needle
- Remedied by stitching on a slightly bias angle where the fabric is hard woven, adjusting the feed mechanism or changing the needle.
?Improperly formed stitches
- Causes reduced stretch in the stitch line, causes needle thread to show on the underside or bobbin thread to be visible on top
- Caused by poor tension, incorrectly adjusted stitch timing or improperly fitting machine components
- Remedied by adjusting the feed mechanism, stitch timing, tension.
Variable stitch density
- Caused by insufficient foot pressure, slippery or sticky surface of fabric
- Remedied by increasing the pressure or using specialized feed systems.
Co-founder & Director, Vidyadhara Consultancy LLP.
