Defects in Core Spun Yarn

defect in Core Spun Yarn

  1. Grin-Through — This defect is an incomplete covering of the core of spandex and is caused by improper positioning of the core with respect to roving.
  2. Short core voids — This defect comes in short sections (25 to 75 mm) of yarns with no stretch because the core broke after the yarn was spun. This may happen due to poor positioning of spandex yarn to roving, over-drafting of core yarn (use recommended drafts), poor mechanical condition of rings, excessive traveller speed, and too heavy traveller
  3. Long core voids — It is long section of yarn with core missing. This defect may arise due to nicked or rough guide surfaces, back drafting of spandex on the tube resulting from insufficient feed-roll contact, over drafting of core yarn and mishandling of spandex supply tubes
  4. Sheath Voids — The causes of this defect are breaks in roving during drafting, over drafting of roving, poor quality roving, improper position of roving allowing pneumafil to rub staple fibres and worn cots, aprons
  5. Selvedge curling — the selvedge of the fabric gets curled because of the yarn behavior and low weave strength of the selvedge.
  6. Holes in the fabric — this defect arises due to; low yarn TM (twist multiplier), strong finishing treatments (which may abrade the  surface of the yarn), splice failure (low splice strength)
  7. Spandex miss – this is caused mainly due to splice failure and due to broken spandex (caused by surface damage)
  8. Cloudy fabric appearance: caused due to high short term count variations even though the average count is within the acceptable limits.



Concept of Stretch in Fabric


The woven and denim garment in general has almost nil stretch making the garment less comfortable and rigid as compared to knit garments, whereas knit garment has a property of de-shaping over a period of use making it less attractive and more prone to deforming as compared to woven garments.

By adding INVIYA® – bare spandex to both woven and knit category of fabrics, woven and denim garments become stretchable and knit garments retains its shape with longer period of use, thus adding value to the entire range of garments.

The entire notion of adding bare spandex to the core yarn of a fabric is to enhance the below properties of the final fabric:

  • Stretchability
  • Drape – gives good drape
  • Good Stretch recovery
  • Wrinkle resistance

 With the more active lifestyle and changing requirement in everyday life it is required more than ever to have a fabric which will not only compliment these conditions but also enhances our daily experience of clothing.

Introduction of stretch in fabric has taken a new turn with different variants of bare spandex yarn used. For example: to make fabric Chlorine resistant – we use chlorine resistant spandex in core so that it doesn’t deteriorate with prolonged exposure to water, scented/ anti-odor bare  spandex is used to eliminate any kind of odor produced by prolonged use of  the end garment in high physical activity etc.

Thus, use of spandex in core of the fabric has not only made the fabrics we use more compatible to our daily lifestyle but in many ways enhanced the way we live in 21st century.

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