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.

Objectives:

To measure the crease recovery of the given sample.
Factor affecting crease recovery:
Fabric structure or construction.
Pressure applied.
Time of pressure.

Theory:

Crease recovery is a measure of creases resistance, specified quantitatively in terms of crease recovery angle. To make 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 0⁰ then recovery is zero and if the angle is 180⁰ 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.

Apparatus:

Crease recovery tester.
2. Scissor.
Glass plate.
Steel plate.
Weight.

Sample:

Cotton woven fabric, Size: 4.4 ×1.5 cm.

Atmospheric condition:

Wet condition: – 26 ° c. & Dry condition: – 30° c.
Difference between wet and dry bulb = 30° c-26 ° c. = 4° c
So, relative humidity (RH) = 70 %

Machine specification:

Name : Wrinkle Recovery Tester.
Brand: TAIEI KAGAKU FEIKI LTD, Japan
Scale : 0⁰-180⁰

Procedure:

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

Data:

Serial no.	Warp		Weft
Serial no.	Recovery angle	Average	Recovery angle	Average
1	70⁰	57.4⁰	41⁰	41.8⁰
2	40⁰		39⁰
3	52⁰		44⁰
4	60⁰		37⁰
5	65⁰		48⁰

Result:

Crease recovery angle of warp way is 57.4⁰
Crease recovery angle of weft way is 41.8⁰

Remark:

Crease recovery is determined depending upon the recovery angle. If the angle is 0⁰ then recover is zero and if the angle is 180⁰ then recovery is full. Here the recovery angle for the given sample is the middle of the range. So it is to say that the crease recovery of the sample is average.

Conclusion:

Crease recovery is an important property of fabric for different end uses. This behavior can be imparted fabric by different finishes. By this practical we learn how to determine crease recovery of fabric by Shirley recovery tester. This practical will help us in our study life as well as job life. Especial thanks to our teacher and his assistants for great co-operation.

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Determination of light fabric strength by Good Brand / Vertical strength tester(Opens in a new browser tab)

Cotton yarn count by Beesely Balance(Opens in a new browser tab)

Cotton yarn count by Wrap Reel & Balance

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