Which machine is used to determine rubbing fastness?

The machine commonly used to determine rubbing fastness in colorfastness testing is called a "Crockmeter" or "Crocodile" machine. The Crockmeter is specifically designed to simulate rubbing or friction that might occur during normal use or laundering of materials, such as textiles, fabrics, prints, and other colored surfaces.

The Crockmeter consists of a rubbing head, which applies controlled pressure and motion, and a rubbing material (usually a standardized white cotton cloth) that rubs against the test sample. This machine allows for consistent and repeatable testing conditions, making it an essential tool in evaluating the colorfastness of materials.

During the rubbing fastness test using a Crockmeter, the amount of color transfer or staining on both the rubbing material and the test sample is assessed. This helps determine the material's resistance to color transfer and provides insights into its overall quality and durability.

The Crockmeter is widely used in industries such as textiles, apparel, upholstery, and printing to ensure that colored materials maintain their color integrity and do not cause unintended color transfer or staining.