What is color fastness?

Color fastness refers to the degree of fading of dyed fabrics under the action of external factors or the degree of staining with other fabrics during use or processing. It is an important index of fabric.

External factor

External factors include: friction, washing, light, seawater immersion, saliva immersion, water immersion, sweat immersion, etc.

In the testing process, it is necessary to select the corresponding test items and test parameters according to different external environmental factors.

Chemical and physical color fastness

Chemical color fastness refers to the color change of colored textiles caused by chemical factors caused by the destruction of the dye molecular chain or the destruction of the color group.

Physical color fastness refers to the color change caused by the dye part separating from the fiber caused by the external physical environment factors or the color contamination caused by the dye falling off from other fabrics.

How to evaluate color fastness

The evaluation of color fastness can be divided into two parts: color fastness and color fastness.

The color changing fastness and color cling fastness caused by physical environmental factors need to be assessed, such as water stain color fastness, washing color fastness, perspiration color fastness, saliva color fastness, dye transfer and other items, and there are only items that assess color cling fastness, such as friction color fastness.

Chemical factors caused by the general test only color changes, such as light color fastness, chlorine bleaching fastness, non-chlorine bleaching fastness, dry cleaning fastness, phenolic yellow fastness.

What is discoloration

Colored textiles in the use or processing process under the influence of external environmental factors, the dye part of the fiber, dye molecules of the chromophore is damaged or generated new chromophore, resulting in color chroma, hue, brightness change phenomenon, called discoloration.

What is staining

Under the action of external environmental factors during the use or processing of colored textiles, the dye is partially detached from the fiber, dissolved into the treatment solution, and re-adsorbed by the undyed white or natural multi-fiber cloth or single-fiber cloth. The phenomenon of contamination of undyed multi-fiber or single-fiber cloth, such as water washing color fastness, water stain color fastness, sweat stain color fastness, saliva color fastness, etc., belong to this phenomenon.

What is solution staining

Refers to the test washing color fastness test, the dye or pigment in the colored textile falls off into the detergent, so that the detergent pollution.

What is self-dipping

Also known as self-dipping, refers to colored textiles, there are two or more colors, in a variety of color fastness test conditions, two colors with each other, such as yarn-dyed fabrics, printed fabrics, two-face fabrics, etc., can be tested for self-dipping color fastness, for pure color (one color) fabrics are not required. At present, many domestic product standards, basically did not introduce the concept of self-dipping color, foreign trade orders as a routine requirement.

Method of expressing color fastness levels

The color fastness rating is basically according to 5 levels and 9 files, and there are two kinds of AATCC standard system and ISO standard system (including GB, JIS, EN, BS, DIN).

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