Crease Recovery Test of Fabric by Shirley Tester

In this article, we are going to test fabric crease recovery by the Shirley crease recovery tester. The process and the machine description are described below.

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Introduction

Crease or creasing of textile material is a complex effect involving tensile, compressive, flexing, and torsional stresses. It is a fold-in fabric introduced unintentionally at some stages of processing. Crease recovery is a fabric property that indicates the ability of the fabric to go back to its original position after creasing. On the other hand, the crease recovery angle is a measure of crease resistance.

Objectives

To know about the crease in textile materials
To know about the crease recovery tester and its functions
To know about the importance of crease recovery test for textile
To know about crease recovery factors for textile material.

Apparatus

Shirley crease recovery tester
Scissors
Stopwatch
Deadweight etc.

Working Principle

Crease recovery is the property of the fabric by which the crease is recovered without any external force after applying load. Here, the Shirley crease recovery tester and loading device are used to determine the recovery properties of fabrics by creasing in a loading device for a pre-determined time using a weight suitable for the test method. After transferring, the specimen is allowed to recover and the angle of recovery is recorded.

Shirley Crease Recovery Tester Figure

Shirley Crease Recovery Tester

Crease Recovery Tester: The top of the machine consists of a dial, and the dial is graduated in degrees. The center of the dial is graduated with a sample holder. Below the dial, there is a levelling screw and a loading place for dead weight.

Working Procedure

1. At first, the specimen is cut according to the template size(4 cm ✕ 1.5 cm).

2. Then carefully given load for crease by folding half.

3. After 1 min, the weight is removed and given some time for recovering crease.

4. Then clamped the fabric on the instrument.

5. The instrument is related to keeping the free edge of the specimen in line with the knife edge.

6. Then recovery angle is read from the engraved scale.

7. In this way, 5 times repeated the test in the warped way and 5 times repeated in the weft way.

8. The mean value of the recovery angle is taken and thus crease recovery is measured.

9. Then SD & CV % is also calculated.

Sample Fabric for Crease Recovery Test

Table 1: Experimental Data for Crease Recovery Angle (Warp Way)

Observed no	Crease recovery angle (x)	Average X	(X-x)	(X-x)²
1	61	61.8	-0.8	0.64
2	61		-0.8	0.64
3	64		2.2	4.84
4	63		1.2	1.44
5	60		1.8	3.24
				Σ(X-x)² = 10.8

Table 2: Experimental Data for Crease Recovery Angle (Weft Way)

Observed no	Crease recovery angle (x)	Average X	(X-x)	(X-x)²
1	59	58	1	1
2	61		3	9
3	58		0	0
4	55		-3	9
5	57		-1	1
				Σ(X-x)² = 20

Calculations

Calculation of Crease Recovery Testing

Result

The crease recovery angle for the warped way is 61.8° and the crease recovery angle for the weft way is 58°. Here, the CV % of the weft way is more than the warped way. So the more accurate values are taken in a warped way.

Conclusion

The crease recovery test is an important test for the textile sector. Through it, we can identify the fabric's nature, property, and quality. Through this experiment, we found out the crease recovery angle of the warp way and weft way. If the crease recovery angle is more than the fabric, crease recovery will be high.

Crease recovery angle ↑ Fabric crease recovery ↑

Crease recovery angle ↓ Fabric crease recovery ↓