The Importance of Color Fastness Testing

Colorfastness refers to the washing and friction resistance of textiles. The quality of color fastness is directly related to the health and safety of the human body. In the process of using the product with poor color fastness, when the products across the rain and the sweat, which will result in the pigment on the fabric faded off, even the molecules and heavy metal may be absorbed by the human body through the skin and endanger the health of the skin. On the other hand, the cloth with poor color fastness will cause other clothes to be stained with color and dye other clothes when washing with other clothes.

The Test Principle of Colour Fastness to Washing

Install stainless steel cups containing samples, detergents and steel beads on the main shaft, heat the water in the box to a fixed temperature. Then start the motor drives the spindle to rotate at a speed of 40 rpm, which causes the samples and steel beads in the cup to rub each other for a certain time in the environment of the washing liquid at a certain temperature. Finally, rinse and dry, grade with the standard sample, and get the test results. Different test methods have the different temperature, alkalinity, bleaching condition, friction condition and sample size, which should be selected according to the test standard and actual conditions.

Test Standard for Colour Fastness to Washing of Textiles

The washing fastness of textiles refers to the ability of the textile to maintain the original color under the washing condition, that is, the ability of not fading and changing color. ISO 105C01-C05 provides several test methods for color fastness to washing, covering the range from mild to the intense washing operation, as a classic colorfastness test method, which is still widely used today. The determination of color fastness to washing of the whole cotton fabric using washing fastness test ISO 105-c03 method, China’s GB/T 3921 3-1997 standard is based on the modification of the formulation, so its technical content and international standards are not different, applicable to any form of textiles.

In addition to the above 2 standards, there are many international standards on the testing of color fastness to water, such as AATCC 61-1A of US, British BS 1006-C01, ISO 105-c06 of the ISO, JIS L0844 of Japan, etc.

Test Procedure

1 Set the working temp and working time as the standard requirement.

2 Add the detergent solution and steel balls to the cylinder as standard requirements.

3 Place an equal number of washpots on each side of the shaft. Start the motor rotation and run for at least 2 min to preheat.

4 After preheating, put the ready samples into the washpots sequential and clamp the lid. Start the machine and run at 40 rpm for a certain amount of time.

5 After the machine stops running, the sample should be washed with distilled water or ionic water, the excess moisture is extracted by centrifuge, and the sample is dried by a possible method.

6 Evaluate the sample according to the standard sample.