TESTING OF HAIRINESS

Defination of Hairiness:-

Spun yarns which are spun from staple fiber are hairy. It means that fiber ends come out of the main body of the yarn and it's surface becomes hairy . It is a type of yarn fault . Sizing is done before looming the warp yarn to reduce its Hairiness and after grey fabric is measured, Sizing is done to remove hairly fibers from fabrics surface . Hairiness consist of protruding fibers , loop fibers , and loosely wrapped wild fabrics.

image of Hairiness on fiber.

Effect of yarn Hairiness:-

In spun yarn, Hairiness is caused by the fiber protruding out of the yarn. The following are the effect of Hairiness on yarn and fabrics qualities,:-

1) It imparts fuzzy appearance to the yarn and reduce luster of the yarn .

2) It affects proper sizing of the yarn .

3) It causes more yarn breakages during weaving due to the hairs in adjoining threads sticking together.

4) It reduces fabric quality by creating weft bars in the fabric.

5) It causes greater pilling in the case os polyester or cotton blended yarn.

Hairiness testing Machine available in market are,

1) Shirley-Atlas hairiness tester.

2) Zweigle hairiness tester.

3) Meiner Dell hairiness tester.

4) Changing hairiness tester.

5) Uster tester.

6) Premier hairiness tester..

Shirley Yarn Hairiness Tester:-

It is working on photo electronic principle . Here optical technique is used to detect the fabric protruding from the body of the yarn.

imge of Shirley yarn hairiness tester. Name of the machine parts. 

A=Yarn package.

B=Yarn.

C=Thread guide 

D=Tensioner.

E=Light source.

F=Photo-cell with hairiness adjuster.

G=Counter.

H=ON/OFF Switch.

I=Yarn speed controller.

J=Yarn take-up.

The machine consist of a photo-cell and bulb from which a beam of light is made to fall on the photo-cell. The tester is provided with a tensioner by which constant tension of 20 grams is given to the yarn and a thread guide which is accurately locates the axis of the yarn relative to the beam of light and the photo-cell. The instrument can be set to measure the number of protruding fibers , protruding by 3 mm and above . A fine digit counter records number of protruding fibers. The speed of yarn through the tester can be controlled between 60 to 120 yards per minute. 

The yarn to be tested is passed through the tensioner and in between the photo-cell and lamp. As the yarn drawn over the thread guide , the projecting fibers momentarily interrupt the light beam. The resulting signal from the photo-cell is amplified and if then exceed to certain threshold lever, it is counted and displayed on the counter. The yarn so drawn is then wounded on a winding drum whllose speed can be varied between 60 and 120 yards per minute.

Ref:-https://textileapex.blogspot.com

Testing of Hairiness:-

This test is very essential after the manufacturing yarn of natural fibers,  such as cotton, wool, silk, etc. There are different methods of testing the Hairiness. 

Methods of yarn Hairiness testing:-

The measuring principle is based on evaluation with diffetacted light. Hairiness value H is defined as the total length of all fibers ends sticking out in cms.

Ref:-https://www.suessen.com

fig of Hairiness tester. Ref by textile Apex.

There are different methods of testing yarn Hairiness is as follows.