Crock-meter is used for determination of color fastness of dyed or printed textiles or leather is the crocking test. This test is used for the determination of color fastness against rubbing, either under dry or under wet conditions. In this test and moving brass finger of specified shape and size rubs against the test specimens under test and the amount of color transferred to a piece of abrading fabric fixed over the base of the moving finger are graded with the help of standard grey scales to evaluate the color fastness against rubbing.

It 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 finger has a flat circular rubbing face which is covered with 4 piece ofWhite abrading fabric during the test. The abrading fabrics pick up color lost by the test specimen during rubbing. It is held over the finger with the help of a tapered ring. Motion to the finger is given through a reciprocating arm with runs on two ball bearings to minimize friction and to apply a uniform load on the finger. The arm is moved by a manually operated crank and connecting link. The equipment is finished in dark metallic paint and bright chrome plating to give it a corrosion resistant finish.

TECHNICAL DATA

• Diameter of the Finger: 16 mm for Textiles / 25 mm for floor covering.
• Load on the finger: 900 g
• Length of travel of the finger: 100 + 3 mm
• Size of the test specimen: 200 x 50 mm

RELATED STANDARDS

• IS 766 :- 1988 Method of Determination of color Fastness of textile materials to rubbing.
• AATCC Method 8 :– 1969 Color Fastness to Crocking (Rubbing)
• ISO RIOS (X12) :– 1984 Textiles - Test for color fastness part.
• Part X12 :- Color Fastness to rubbing.
• IS 6191 :- 1971 Methods of Micro-Biological color fastness and microscopically tests for leather.