Yarn Quality Requirements for knitting

Yarn Quality Requirements for knitting

The yarn characteristics have a major influence on the performance of knitting as well as on the apperance of finished fabric. Improvements... 10:42 AM

The yarn characteristics have a major influence on the performance of knitting as well as on the apperance of finished fabric. Improvements in the performance of knitting industry demand improvements in the knitting machines as well as optimisation of yarn properties. Various hosiery yarns are manufactured using the range of fibres available to suit different end uses. In Bangladesh, India majority of the knitted products are made from cotton yarn.

The following are the important yarn quality requirements for efficient running on knitting:

• High work of rupture value.
• antial elongation at break.
• Low flexural, torsional and initial stretch resistance.
• Good resilency.
• High ratio of parimary to secondary creep.
• Reasonable tenacity and loop strength.
• Resistance to fatigue due to cyclic stress and strain.
• Regularity of physical characteristics such as twist, evenness, moisture content.
• Smooth and low frictional properties.

Conditioning at yarn prior to kintting at a standard atmosphere of 65±2% RH at 27∘C temperature for 24 hours to 48 hours will give good results in knitting. Moisture content of cotton and cotton blended yarns not only affects knitting performance but also helps in maintaining consistency of fabric weight. Hence a moisture meter should be used so as to quickly establish yarn fabric moisture. 

To prevent snarling, steam setting is essential for polyester blends. The recommended steam setting conditions are:

Vacuum Gauge - 740mm Hg

Temperature - 95 - 110 c

Time Duration - 15 to 30 min

In high speed knitting the knitting performance with respect to yarn hairiness is to be considered o the following accounts:

• Excessive yarn hairiness causes excessive yarn friction between yarn and metal , which hinders proper loop formation and particularly with cotton yarn, general lots of fly.
• It spoils the fabric appearance and causes excess pilling.
• It also gives improper dyeing.