fabric Properties

Crimp in Textiles | Crimp %, Crimp Rigidity & Crimp Ratio

Definition of Crimp

When warp and weft yarn interlace in fabric follow a way patch which is known as crimp.
According To Pierce, “Crimp, geometrically considered, is the percentage excess of length of the yarn axis over the cloth length”.

Crimp Percentage

Crimp Percentage is defined as the mean difference between the straightened thread length and the distance between the ends of the thread while in cloth, expressed as a percentage.

Crimp Ratio

It means the ratio of yarn length to fabric length. Crimp C= l-P/p.

Take Up Percentage or Crimp Rigidity

Take up percentage or crimp rigidity is a measure of the ability of textured yarn to receive from stretch. It is the ratio of reduced length to original length, expressed as percentage.
Thus, take up percentage T% = L – P/ L × 100.

Effect of Crimp in Fabric Properties & How Crimp Is Measured?

There are several important effects of crimp on Fabric Properties:-

1. Abrasion Resistance: If crimp percentage is high then the resistance of the fabric will be higher.
2. Shrinkage: If crimp percentage is high then the shrinkage of the fabric will be lower.
3. Handle Properties: When the crimp percentage is higher, the softness of the fabric will be fiber. Simultaneously stiffness of the fabric will be lower.
4. Fabric Design: Required extensibility is achieved by controlling crimp.

Now, how can we measure the crimp percentage of a fabric or yarn?
Here I will show you a way that is followed by WIRA Crimp tester machine.
Firstly a thread (which may be warp or weft) is collected from a fabric with crimp. Now the crimped length is measured. The length will be found is the cloth length which is denoted by “p”.
Now, the yarn is straightened and measured. A length will be found which is denoted by “l”.
So the Crimp % of the Fabric will be =     l-p/p- × 100
In this way several crimp percentage measurement is done and result is taken. By using all of the result and mean value is derived.