DETERMINATION OF ABRASION RESISTANCE OF FABRICS

Plain Abrasion Resistance

Apparatus - Universal Wear Tester

Prior to test, the fabric should be Conditioned to moisture equilibrium from the dry side, in the standard atmosphere of 65+-2% relative humidity and 27+-2 deg C temperature. The test should be carried under standard atmospheric conditions.

Method for determination of plane Abrasion Resistance

1. Cut five circular test specimens of 112 mm in diameter, taking care to take specimens from areas containin the same wales or courses in knitted fabric or the same warp or weft yarn in woven fabric.

2. Set the instrument for inflated diaphram test.

3. Place the specimen over the rubber diaphram in smooth condition and clamp the specimen in place without disturbing it.

4. Place the abrasive paper on the abradent plate under sufficient tension to be held smooth and in such a position that the contact pin, reaching through a hole in the abradent is even with the surface of the abradent. In the absence of any specific material specification , zero emery polishing paper should be used as the abradent.

5. Set the air pressure under the diaphram and load on the abradent plate. In the absence of any specific material specifications, the air pressure should be 0.3kg/sq.cm (4 p.s.i.) and the load on the abradent should be 454 gm. Ensure that the air pressure control and contact between the inflated specimen and loaded abradent is in a state of equilibrium before abrasion is started. To ensure consistent inflation of the diaphragm, inflate to a higher air pressure ( 25 per cent) and then reduce the testing pressure.

6. If the unidirectional abrasion is desired, disengage the rotation mechanism of the specimen clamp and bring the specimen into the direction by turning and setting the clamp after the diaphragm has been inflated.

7. In the event that multi-directional abrasion is required, or if no specific indication as to the abrasion direction is given in the fabric specification, engage rotation mechanism of the specimen clamp.

8. Remove pills of matted fibres interfering with proper contact between specimen and abradent during the test if they cause a marked vibration of the abradent plate.

9. If the specimen slips in the clamp or the air pressure does not remain constant during the test or anomalous wear pattern is obtained, discard such individual measurements and test an additional specimen..

10. One of the following methods is selected for determination of end point as per test specifications:

a. Breakage of Thread: Abrade the specimen until all fibres in the centre of the abraded area are worn off so that the diaphragm and abradent head come into contact and the instrument automatically stops.

b. Removing a predetermined thickness of the material. Abrade the specimen using the electrical depth micrometer to determine the automatic end-point for removing a predetermined thickness of the material from the specimen.

11. Unless the continuous changing abrasion head is used, abradent paper is changed after every 300 cycles.

12. Report shall include the following information :

a. Type of abradent
b. Type of abrasion ( unidirectional or multi directional)
c. No. of cycles to reach the end point as determined by electrical contact.