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Crockmeter for Textiles:
One
of the test for determination of colour fastness of dyed of printed
textiles or leather is the crocking test. This test is used for the
determination of colour fastness against rubbing, either under dry or
wet condition .In this test a moving brass finger of specified shape
and size rubs against the test specimens under a fixed load. The
amount of colour lost by the test specimen and the amount of colour
transferred to a piece of abradant fabric fixed over the base of the
moving finger are graded with the help of standard grey scales to
evaluate the colour fastness of the sample under test rubbing.
The hand operated “ASIAN”
Crockmeter consists of a rigid flat metallic platform on which
the test specimen can be held firmly and a abrading finger which rubs
against it under a specified load. The platform is fixed over the
base of the equipment and lies in a horizontal plane. The test
specimen is held firmly over an abrasive paper, which is pasted on
the upper face of the platform with the help of two pins holding it
at both ends.
The abrading has a flat
circular rubbing face, which is covered with a piece of white
abradant fabric during the test. The abradant fabric picks up colour
lost by the test specimen during rubbing. It is held over the finger
with the help of a spring grip. Motion to the finger is given through
a reciprocating arm, which runs on two wheels to minimize friction
and to apply a uniform load on the finger. The arm is moved operated
crank and connecting link.
The equipment is finished
in dark grey metallic painting and bright chrome plating to give it a
corrosion resistant finish
Technical Specifications:
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Diameter of the finger
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16 mm
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Load on the finger
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900g (150g for leather)
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Length of travel of
the finger
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104 ±3mm
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Dimension of test specimen
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250 X 50 mm
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