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CROCKMETER FOR  TEXTILES

           
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                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 DATA

Diameter of the finger                      : 16 mm
Load on the finger                             : 900g (150g for leather)
Length of travel of the finger         : 104 ±3mm
Dimension of test specimen             : 250 X 50 mm  

RELATED STANDARD:
IS 766-1988                         : Method of determination of Colour fastness of Textile Materials to Rubbing.                     
AATCC Method R-1969   : Colour fastness to Crocking(Rubbing)
ISO R105 (X12)- 1984      :Textiles- Test for colour fastness Part x 12: Colour Fastness to Rubbing.