Monday, May 1, 2017

How to Identify the Substance of Textile Yarn

To determine what the substance is of the yarn that you are looking at sometimes is difficult. It requires good knowledge and experience to make a good judgment. If you want to be very accurate you have to send it to a lab for a scientific analysis. However, as garment merchandiser, we should be able to use some technique to get the answer quickly.

Techniques to identify the substance of textile yarn:
The following are methods that you can use to analyze the yarn yourself without any equipment.

 
Yarn burn test
Fig: Yarn burn test
Natural fiber:

Cotton:
When you untwist unravel the yarn and pull out staples from it, you will see that all the staples are less than 2”. When you burn it, it burns to grayish white ash like burning paper.


You can also read:  Properties of Cotton Yarn

Silk:
When you untwist, unravel the yarn and pull out the fibers from it you will see the fibers are much longer than 2”. They are very fine and soft. When you burn it, it burns to dark grey hard ash (like a bubble). You can crush it by hand into dust.

Ramie:
When you untwist, unravel the yarn and pull out the fibers from it you will see the fibers are much longer than 2”. They are thick and stiff, not too pliable. When you burn it, it burns to grayish white ash similar to cotton.

Wool:
When you untwist, unravel the yarn and pull out the fibers from it you will see the fibers are much longer than 2”. They are not very straight and not very fine and pliable. You should suspect either it is wool or synthetic. When you burn it, it gives you a very strong smell like burning human hair. During the process of burning it does not melt.

Synthetic fiber:
Unless you go for a sophisticated analysis by a laboratory, you cannot tell what kind of synthetic fiber it is other than separating rayon from other synthetic material.

Rayon:
If it is rayon, when you untwist, unravel the yarn and pull out the fiber you will see that the fiber length is very long, very soft and even in thickness. When you it, it burns like paper or cotton to grayish white ash. In the process of burning you do not see anything melting.

Polyester, nylon, acrylic:
If it is polyester, nylon, acrylic etc… all those from petroleum, when you untwist, unravel the yarn and pull out the fiber from it you will see that the fiber lengt5h is very long, and even in thickness. When you burn it, it melts first. When it catches fire, the smoke is back.

(Rayon is made of pulp which comes from mashed wood and that is why it burns like paper or cotton. Polyester, nylon, acrylic etc are side products of petroleum, and they burn like plastic or petroleum.

The above is a guideline to find out approximately what substance it is. It needs goods experience and skill to do it. If you practice often you can tell what it is without too much difficulty. If you need to know the percentage of the blended yarn, you have to use a laboratory to do an analysis. If you only wish to know what they are, you can use the above methods to get a good idea.