How to test color fastness to rubbing?

Testing color fastness to rubbing requires the use of a rubbing color fastness tester, usually a rubbing head (such as a rubbing finger or rubbing cloth) and a corresponding rubbing rod or rubbing arm. The following is the general test procedure:

1. Preparation of the sample: Preparation of the sample requires that it be cut to the appropriate size for the test as required. For textiles, a sample size of 2.5 cm x 5 cm is usually used and pre-treated (e.g. washed and dried).

2. Mounting the sample: Clamp the sample on the tribometer and make sure it is securely fastened. The friction head should be pressed against the surface of the sample to be tested.

3. Setting the test parameters: Set the parameters of the Tribometer, such as friction force, friction speed and number of reciprocating frictions, according to standards or requirements. These parameters may vary according to different applications and standards.

4. Perform the test: Start the tribometer and rub the friction head back and forth across the sample surface. A check is usually made after each reciprocal rubbing to observe pigment transfer or color change.

5. Evaluate test results: After completing the test, the sample is evaluated for color change and pigment transfer by comparing it to a standard. This can be done using a gray scale standard or scoring system. Depending on the degree of color change, the results are given the appropriate color fastness to rubbing rating.

It should be noted that different industries and applications may have their own specific requirements and assessment methods. The color fastness to rubbing test can also be adapted and modified to suit specific materials or products.

With the color fastness to rubbing test, it is possible to assess the abrasion resistance and color stability of a material in use. This is important for applications related to color stability such as textiles, leather, coatings and printing. Test results can help guide material selection, product improvement and quality control to ensure that products will reduce color variation and fading in actual use.