Problems In Application Of Water Fastness Standard For Textiles

Water resistance

An important test item for textiles is one of the evaluation criteria stipulated in the mandatory national standard GB18401 national textile product basic safety technical specification.

At present, the water fastness standard of textiles used in China is GB/T5713 - 1997. The color fastness test of this standard is equivalent to the international standard ISO105-E01:1994.

Water fastness is directly related to the performance of textiles. However, there is a special situation in practical testing. That is, some printing fabrics will produce visible impressions after drying by water. However, according to the current standards, the fastness of water fastness is tested, but the degree of fastness of detection is very high. Therefore, the test results can not reflect the actual performance.

Problems in application of standards

The samples for the test are reactive dyed fabric and white deep blue.

According to the test of GB/T5713 - 1997, the grade of color change and the level of staining are all 4~5, which has reached the most stringent requirement of class GB18401 "3~4 or more". The detection level is very high.

According to the standard test results, the water color fastness qualification report can be issued. However, there are obvious problems in the actual use of the fabrics made by this fabric, and the prints appear after drying.

After printing, fabrics may remain unfixed dyes or hydrolyzed dyes. Reactive dyes are water-borne. When washing, the water will move with the movement of water.

Dye accumulation is formed on the surface of the fabric, and prints are produced at the dye accumulation.

GB/T5713 stipulates that when samples are dried in air, once air dried samples are found, they must be abandoned and redone.

This rule is due to the loss of moisture in drying samples when drying occurs. The dye on the top will cause uneven distribution due to the movement of swimming, and the final result can not be accurately evaluated.

Drying is not avoided when washing and drying.

There may be similar perplexities in the undertone of light or bright coloured dyed fabrics, that is, the color fastness to water fastness is completely qualified after the standard test. However, when larger samples are dried and dried, they will be imprinted because of the dye migration.

In addition to the GB/T5713 and the equivalent ISO105-E01:1994, the current standard for fastness to water color is the standard AATCC107 of the American Association of dyeing and chemists and the Japanese industrial standard JISL0846.

There are some differences between these standards in constant temperature time, lining fabric selection and oven temperature. A large number of samples have been tested by the researchers. It is found that different water fastness standards have little difference in color fastness to the same fabric, and the difference of stain is relatively large. However, the standard detection principles and processes are basically the same, which can not reflect the actual performance of such special situations.

Because this fabric is white printing, the color is dark, and the difference is obvious. This requires that its color fastness is much stricter than ordinary printing.

If

The color and color are similar. With the same technology, even if there are "prints", they may not be able to be seen because of the color of the ground.

Therefore, printing and dyeing production, for such samples in printing, fixing and washing each process must be strict requirements, any process of omission may be a problem.

As a matter of fact, the sample of this problem was not re printed after printing, dyeing, soaping and rinsing.