Determination of Fabric Crease Recovery by Shirley Crease RecoveryTester

Name of the Experiment: 
Determination of fabric crease recovery by Shirley Crease Recovery Tester.

Introduction:
Crease is a fold in fabric introduced unintentionally at some stages of processing. Crease or crushing of textile material is a complex effect involving tensile, compressive, flexing and torsional stresses. Crease recovery is a fabric property which indicates the ability of fabric to go back to its original position after creasing.

Objective:
To measure the crease recovery of the given fabric.

Theory:
Crease recovery is a measure of creases resistance, specified quantitatively in terms of crease recovery angle. To measure this, the popular instrument is Shirley crease recovery tester. The instrument consists of a circular dial which carries the clamp for holding the specimen. Directly under the centre of the dial there is a knife edge and an index line for measuring the recovery angle. Crease recovery is determined depending upon this recovery angle. If the angle is 0o then recovery is zero and if the angle is 180o then recovery is full. Crease recovery depends on the construction, twist of yarn, pressure, time etc. Usually crease recovery is more in warp way than in weft way. This is because warp yarns are well in quality, strength, treated with sizing, kept in more tension during weaving etc.

Crease Recovery Tester

Apparatus:  

1. Crease recovery tester
2. Scissor
3. Glass plates
4. Steel plates
5. Weight.

Sample:  

• Cotton woven fabric.
• Size: 4.4 X 1.5cm.

Atmosphere:  

• Temperature – 25oC and relative humidity – 67%
• Standard atmosphere: temperature – 20oC and relative humidity - 65%.

M/c specification:  

• Name: Wrinkle Recovery Tester
• Brand: TAIEI KAGAKU FEIKI Ltd., Japan
• Scale: 0o-180o.

Procedure:

1. The specimen is cut by template and carefully creased by folding in half.
2. The crease is imparted on fabric by placing it between two glass plates and adding to 500gm weight on it.
3. After 1 min the weight is removed and the creased fabric is clamped on the instrument.
4. Then it is allowed to recover from the crease. The recovery time may vary to suit particular creases. Usually it is 1 min.
5. When crease recovers the dial of the instrument is rotated to keep the free edge of the specimen inline with the knife edge.
6. The recovery angle is read from the engraved scale.
7. In this way 10 tests are done in warp way and 10 for weft way.
8. The mean value of recovery angle is taken and thus crease recovery is measured.

Data:

S/n	Warp		Weft
	Recovery angle	Average	Recovery angle	Average
1	70o	57.4o	41o	41.8o
2	40o		39o
3	52o		44o
4	60o		37o
5	65o		48o

Table: Recovery angle obtained from test

Result:  

1. Crease recovery angle in warp way is 57.4o.
2. Crease recovery angle in weft way is 41.8o.

Remark:
Crease recovery is determined depending upon the recovery angle. If the angle is 0o then recovery is zero and if the angle is 180o then recovery is full. Here the recovery angle for the given fabric sample is the middle of the range. So it is to say that the crease recovery of the sample fabric is average.