YARN MAJOR QUALITY ISSUES, DEFECTS & CORRECTIVE ACTIONS:

1. Thick Place:

First major yarn quality problem we found thick & thin places in yarn. A thick Place means voluminous/coarse thread place. Thickening is a yarn defect that adversely affects fabric quality. For ring spun/rotor spun yarn +50% is a valid slab point.

Corrective Measures to be taken to control thick place :
 • Controlling fiber breakage during processing
• Removing short fibers during combing
• Keeping clean of all processing machinery
• Using yarn clearer in Winding
• Proper maintenance of processing machinery

 2. Thin place : 
A thin spot means the spot where the thread is lighter. This is a yarn defect that adversely affects fabric quality.

 Corrective Measures to be taken to control thin place :
 • Control Fiber Breaks During Processing
• Remove Staple Fibers During Combing
• Storage Clean All Processing Machines
• Yarn On Winding Use Clearer
• Proper Processing Machine Maintenance

 

4. Neps: 
The smallest tangle of fibers is called a Neps. This is a yarn defect that adversely affects fabric quality. Neps can be seen on the fabric surface after dyeing and finishing. The nep length is 01 mm.

 Corrective Measures to be taken to control Neps:
 • Getting better NRE of Carding
• Controlling the proper setting of Blow room machinery
• Controlling abrasion /friction during knitting/dying
• Proper selection of Raw cotton

5. Hairiness : 
One of the major problems of yarn is hairiness of yarn. Hairiness means the projected fibers on the yarn surface. All projected fibers are not hair. The fibers whose length is 3 mm+ are hair. Hairiness is the characteristic of the yarn. Lower the hairiness better the yarn quality & better the fabric surface finish. The main difference between normal yarn & compact yarn is hairiness.

Corrective Measures to be taken to control Hairiness :
• Correct selection of raw cotton
• Control of short fibers
• Use of wax
• Control of friction during ring processing
• Controlled winding of hairiness Speed ​​
• Minimizes friction during knitting and dyeing

 

6. Patta : 
Patta means shade variation. This is a defect in the yarn. Following are the reasons for Patta in the fabric. 

 Corrective Measures to be taken to control Hairiness 
• Mixing in yarn count
• Mixing in yarn lot
• Higher percentage of CV yarn
• Tension variation of the knitting machine.

 

7. Contamination: 
Contamination is a foreign matter of yarn. These foreign matters come from raw cotton. Fibers other than cotton are foreign fibers. Polyester, nylon, bird feather, human hair, and pieces of colored fabrics are contaminated.

 Corrective Measures to be taken to control Contamination :
• Manually separate contamination from raw cotton
• Preparation Use a cotton sorter in the process
• Use a yarn clearer for winding
• Select the appropriate raw cotton.

Here above, we have discussed the major yarn quality problem & Corrective measures /actions to solve these problems.