Martindale Abrasion Tester
Determination of resistance of any fabric to abrasion is usually carried out by abrading the fabric under specified conditions against a standard abradant. Although plane abrasion of fabric surface does not cover all aspects of strains that are important in determining service life, there are occasions when such a test gives useful information.
One of the standard equipment used for this determination is the Martindale Abrasion Tester. This apparatus gives a controlled amount of abrasion between fabric surfaces at comparatively low pressures in continuously changing direction. Circular specimens of fabric are abraded under known pressures under a motion which is the resultant of two simple harmonic motions at right angle to each other. The resistance to abrasion is estimated by visual appearance or by finding the loss in mass of the specimens.
The GLOBE Martindale Abrasion Tester consists of a plate which is give a motion combining two harmonic motions at right angle through three rotating eccentric pegs, four number specimen holders for mounting the fabric under test on, and four number abradant holders against which the test specimens are abraded.
The plate is supported on three oilÂlubricated felt discs and has three slots for locating the eccentric pegs in. The pegs are rotated with the help of an electric motor, worm reduction gearbox, and sprockets and chain arrangement such that the central peg is rotating at a slower speed than the two outer pegs, which rotate at the same speed. The movement of the pegs causes the plate to move in two mutually perpendicular directions in simple harmonic motions, thus providing the necessary abrading action.
The test specimens are mounted on flat metallic discs and are backed with a thin layer of polyurethane foam. The shafts of the specimen holders are guided vertically in bushes on the moving plate. Thus the movement of the plate causes the specimen holders to move with the plate, abrading it against the abradant fixed mounted in four holders located below them. The force on the test specimens can be altered by adding or removing dead weights from the specimen holders.
A 'five digit electronic pre-set counter counts the number of rotation of outer pegs and stops the motor automatically after a pre-set numbers of rotations. Templates for marking the test specimens and abradant, disc weights to keep them flat during fixing, and mounting jig for test specimens are provided as standard accessories.
The various components are mounted on a sturdy fabricated steel base and are finished in shore blue matalic painting and bright chrome or zinc plating to give them a corrosion resistant finish.
|Maximum number of test specimens that can be tested at a time |
|Speed of outer pegs |
|47.5 +- 2 rpm |
|Ratio fo speeds of outer pegs to central peg |
|32 / 30 |
|Stroke of pegs |
|60.5 mm |
|Workign area of specimen holder |
|6.45 cm2 |
|Pressure on test specimens |
|3, 6, 9 and 12 KN / m2 |
|Related Standards |
|IS 12673 - 1989 |
|Textile Fabrics - Abrasion Resistance - Methods for Determination |
|BS Handbook 11 |
|Method of Test for Abrasion Resistance of Fabrics |