Analysis Of Color Fastness And Sweat Fastness Of Fabric Washed

1. fastness to washing

Washing or soaping fastness refers to the degree of color change of dyed fabrics after washing, and the degree of staining of other fabrics.

The method of testing is to bind the samples of textile dyeing with one or more of the adhered fabrics, put them in the soap solution, and mix them with the machine at a specified time and temperature. After washing and drying, the dyes on the dyed samples will be faded and adhered.

The degree of staining.

Usually, the grey grading card is adopted as the evaluation standard, that is, judging from the original color and the chromatic aberration after fading.

Washing fastness is divided into 5 grades, the 5 is the best, and the 1 is the worst.

The soaping temperature can be divided into three types: 40, 60 and 95.

The fabric with poor washing fastness should be dry cleaned. If wet washing is done, doubling attention should be paid to washing conditions, such as washing temperature should not be too high, and time should not be too long.

Factors affecting the fastness of soaping

Relating to the selection of dyes.

(1) water soluble dyes, such as direct and acidic, have no change in dyeing properties, and dyestuffs can be dissolved again, so the fastness is poor.

(2) water-soluble or insoluble dyes such as sulfuration, reduction, insoluble azo, good general fastness;

The reaction between reactive dyes and fibers was covalently bonded, and the fastness was good.

It is related to dyeing process: if dyestuff is dyed, floating color is much, and soaping fastness is poor.

It is related to dyeing concentration: floating color with high concentration may affect the fastness more. If the dyeing rate is high and floating color is less, the influence on the fastness of soaping is low.

Related to soaping conditions: pH value, temperature and so on.

2. fastness to perspiration

It refers to the fading degree of dyed fabric after soaking in sweat.

Because the sweat fastness is not the same as the artificial sweat composition, it is usually combined with other color fastness except for individual determination.

The sweat fastness is divided into 1~5 level, the bigger the value, the better.

Sweat fastness test should pay attention to: according to the standard, artificial acid or alkaline sweat must be ready for use now; the adjustment of pH value for artificial sweat preparation; for certain samples that are not easily wetted in the test solution, the necessary press and toggle must be supplemented with the necessary pressing and toggling to make the specimen fully permeated by artificial sweat; in the experiment, the combined samples of acid sweat and alkaline sweat are to be placed on different instruments separately so as to avoid the mutual contamination of the tested liquid; similarly, the samples with different color depth should be separately tested.