CORE YARNS AND PRECAUTIONS NEEDED TO SPUN CORE YARNS

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Mr.S.Sundaravadivel, Vice President, Pallava Textiles Pvt. Limited, Sangagiri, Tamilnadu

Core Yarn: It is a Compound structure consisting of a core surrounded by a fiber, which is suitable to use as a yarn. The core may be rigid or elastic.

Precautions:

1. Selection of superior core spun yarn attachment is more important.

2. Uniform & high quality roving should be used for core spun yarn process.

3. Accurate adjustments of rings and travellers to make better package of cop without forming steps.

4. Good lighting is necessary for easy detection of filament breakage.

5. Excellent cleaning devices to prevent fly deposits.

6. Conditions of cots, aprons and drafting rollers should be strictly maintained.

7. Accurate centering of revolving guides will avoid friction, creating micro breaks.

8. Well trained and motivated operators should be engaged for perfect handling of filament package and yarn piecing, gaiting in spinning.

9. Careful handling & storing of filament material is very important to prevent damages

10. Department temperature and humidity should be strictly maintained at the optimum level.

11. Perfect alignment with roving, higher level of twist, heavier weight travellers are required to avoid core exposure.

12. Proper yarn number calculation and core content determining method should be properly adopted
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Mr.Sankarabagam, Mill Manager, Pariyur Amman Spinning Mill Limited, Gobichettipalayam, Tamilnadu

Core Yarn: This is nothing but Cotton or Polyester yarn blended with filament yarn in ring frame called as Core Yarn.

Precautions:

While producing core yarn polyester / Cotton yarn will be drafted and filament should be processed through front Roller region.

For good blended, we should provide guide in between cradle and front top roller.

Proper piecing method should be implemented in spinning to avoid improper core yarn.

Traverse motion should not be utilised for producing good core yarn.

Precaution should to be taken for keeping the drafting zone clean. Cots, apron condition, should be fluff and fly free.

Buffing should be done for every 30 days for producing Good yarn.

Traveller should be changed once in week. Special creel attachment should to be provided for creeling Filament yarn.
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Mr.V.Balasundaram, General Manager, Vijayeswari Textiles Limited, Pollachi.

Core Yarn: The yarn spun by wrapping the fibres on to a continuous filament is called core yarn. The two types of core yarn are Hard core with core as higher in percentage and it is used in sewing applications and special fabrics (example - Poly core, Poly cotton core, Nylon core, etc., and Fire retardant Kevlar core and Cupro cotton & Silk cotton core for fabrics). The second type is the soft core where the core % is lower and it is used to improve the yarn elasticity, finds its application in various types of fabrics (example - Lycra).

Precautions:

Both these types of core need special care while spinning. One should ensure that proper creel and feeding arrangement is provided with stop motion for soft core. In case of hard core stop motion is not mandatory as it can be easily picked up when core/cover is missing. Optimum unwinding tension of core filament is to be ensured for quality core yarns. Another major factor influencing the quality is the selection of traveller. It is essential that round cross section travellers are selected in order to ascertain that the cover is not disturbed (peeling off). Yarn balloon is to be closely monitored to ensure that it does not touch any parts like separators, empties and gets disturbed. Spindle speeds must be reduced to an extent that breakages are maintained well below 10/1000 spindle hour. Special Training to workers highlighting probable reasons detrimental to quality is a must.
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Mr.S.K. Jindal, General Manager (Spinning), Ginni International Limited, Neemrana, Rajasthan

Core yarn: A yarn in which, one type of fibre is twisted or wrapped around another that serves as a core yarn.

Precautions:

1. Core filament should be totally covered with surrounding sheath fibers & should be at center.

2. Core filament should not be missing at any place in the yarn to provide necessary stop motions for the same

3. Yarn splice quality should be good.

4. Yarn should not get opened during its use
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Mr.P.Marimuthu, Manager – Quality Assurance, Sri Gomathy Mills Pvt Limited, Viravanallur

Core Yarn: One Extra yarn wrapped around main yarn thereby improving yarn elasticity
characteristics, the extra wrapper is inserted at drafting zone with an additional attachment is
called Core Yarn. Examples: Cotton & Lycra

Precautions:

1. Spindle speed should be reduced when compared to normal spinning

2. Increase and improve the illumination to 120 LUX

3. Engage one sider for 1000 spindles

4. Breakage rate should be below 1%

5. Cops should be taken out from ends down spindles and keep the cops separately
and remove the yarn till the core yarn comes to spring action, which is the
indication for Lycra content.

6. Inspection with bright lighting is needed to check Lycra path.

7. Set CA, CCA Setting in Autoconer as 6% to ensure Lycra missing

8. Piecing hands and fingers should be free from dirt and oil

9. Drafting zone and yarn should be cleaned well to maintain the yarn quality.