What are the fastnesses in the laboratory?

1. Dyeing depth

In general: the darker the color, the lower its fastness to washing, rubbing, etc.;

In general: the lighter the color, the lower its fastness to sunlight, chlorine bleaching, etc.

2. Are the fastness to chlorine bleaching of vat dyes very good?

For cellulose dyeing that requires chlorine bleaching resistance, when reactive dyes cannot reach it, vat dyes are generally used, but not all vat dyes (Shilin dyes) are chlorine bleaching resistant, such as vat blue BC, RSN, etc.

3. Fastness on dye color card

When you check the fastness index of a dye, it is usually through the dye color card provided by the dye company, but it should be noted that the fastness index on the dye color card provided by the dye company refers to the fastness level at the standard dyeing depth, not this level for any dyeing depth.

4. About color matching

When dyeing a color, two or three dyes are used together, and the final fastness index is affected by the dye with the worst fastness

5. Rating of sunlight

The American standard AATCC sunlight fastness is a 5-level system, with the highest being 5;

The European standard ISO sunlight fastness is an 8-level system, with the highest being 8, so when choosing dyes, you must see which standard is required.

6. Chlorine water (swimming pool) fastness

The chlorine water fastness (swimming pool) fastness of textiles generally has three concentrations of effective chlorine standards: 20ppm, 50ppm and 100ppm. 20ppm is generally used for towels, bathrobes, etc., while swimsuits are generally suitable for 50ppm and 100ppm.

7. Chlorine bleaching fastness

Non-chlorine bleaching fastness is a test of oxidative bleaching fastness that is different from chlorine bleaching (sodium hypochlorite). It is usually tested with two different oxidants, sodium perborate and hydrogen peroxide.

8. Saliva fastness

Infant textiles are generally required to have saliva fastness, because as we all know, infants and young children will drool and chew their fingers.

9. Migration fastness of optical brighteners

Some European countries have restrictions on fluorescent brighteners in textiles, but for textiles that must use fluorescent brighteners, they can also be used if they have qualified migration fastness.

10. Sweat light fastness

Sweat light fastness is the only composite test method in the color fastness series test methods. It is used to test the degree of discoloration and fading of dyed fiber products under the combined action of sweat and sunlight.

11. Color weeping fastness

Color weeping fastness is also called color migration fastness or color fastness to bleeding. It is rated by the migration and staining of dyes or residual floating colors on fabrics. It mainly reflects the degree of contamination of fabrics caused by dye dissolution and color transfer to white or light-colored base fabrics after washing or being rained. It comes from Japan and is also called "Dawan method" in Japan.