1. Test method for color fastness to water and perspiration
The color fastness to water reflects the discoloration of the textile itself and the staining of the lining fabric under the combined action of certain moisture, pressure and temperature. During the test, after the sample and the backing fabric are fully soaked, put it in an oven at a certain temperature for a certain period of time under a certain pressure, take it out to dry, and evaluate the discoloration and staining grade. The discoloration and staining grades are divided into 5 grades, 5 is the best and 1 is the worst.
The color fastness to perspiration reflects the discoloration of the textile itself and the staining of the lining fabric under the combined action of pressure and temperature in different test solutions containing histidine. The discoloration of the sample and the staining of the lining fabric were evaluated with a gray card, and the results were divided into 5 grades, with 5 being the best and 1 the worst.
2. Ways to improve color fastness to water and perspiration
To improve the color fastness of fabrics to water and perspiration, the most important way is to choose dyes reasonably, especially dyes with high fixation rate and good stability. Reasonably formulate and control the dyeing process, strengthen the fixing conditions, and form a covalent bond with high stability, so that the dye can be fully fixed. For example, when dyeing dyes with poor reactivity, a catalyst can be used, or an appropriate fixing agent can be used, or the color can be fixed at a relatively high temperature.