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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 oillubricated 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.
Technical Specifications
Maximum number of test specimens that can be tested at a time
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Four
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Speed of outer pegs
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47.5 +- 2 rpm
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Ratio fo speeds of outer pegs to central peg
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32 / 30
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Stroke of pegs
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60.5 mm
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Workign area of specimen holder
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6.45 cm2
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Pressure on test specimens
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3, 6, 9 and 12 KN / m2
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Related Standards
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IS 12673 - 1989
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Textile Fabrics - Abrasion Resistance - Methods for Determination
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BS Handbook 11
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Method of Test for Abrasion Resistance of Fabrics
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