Color fastness refers to the washing resistance and rubbing resistance of the product. The color fastness is good or bad, directly related to the health and safety of the human body. During the wearing process, the product with poor color fastness will cause the pigment on the fabric to fall off and fade when it encounters rain or sweat. The dye molecules and heavy metal ions are all It may be absorbed by the human body through the skin and endanger the health of the human skin. On the other hand, it may also affect other clothing worn on the body to be stained, or stain other clothing when washed with other clothing.

Because the conditions of fabrics in the process of processing and use are very different and the requirements are different, most of the current test methods are simulation tests or comprehensive tests according to the working environment and conditions, so the test method of color fastness The content is quite extensive. However, looking at the International Standards Organization (ISO), the American Society of Dyeers and Chemists (AATCC), Japan (JIS), the United Kingdom (BS) and many other standards, the most commonly used are washing resistance, light resistance, abrasion resistance, perspiration resistance, and Ironing, weather resistance, etc. In actual work, the test items are mainly determined according to the end use of the product and the product standard. For example, the wool textile product standard stipulates that the color fastness to sunlight must be tested. Of course, the perspiration fastness of knitted underwear must be tested. Textiles (such as parasols, light box cloth, canopy materials) must of course be tested for color fastness to weather.

Test type

The nature or degree of the variation of the dyeing state can be expressed by the color fastness. The dye fastness of the fabric is related to the type of fiber, yarn structure, fabric structure, printing and dyeing method, dye type and external force. Color fastness tests generally include light fastness, weather fastness, washing fastness, rubbing fastness, perspiration fastness, etc. Sometimes there are some according to different textiles or different use environments. Color fastness for special requirements. Usually, when the color fastness test is carried out, it is the degree of discoloration of the dyed material and the degree of staining to the lining. The color fastness is rated, except for the light fastness of eight, the rest are all five. The higher the grade, the better the color fastness.

Light fastness

Light fastness refers to the degree of discoloration of colored fabrics by sunlight. The test method is to compare the fading degree of the sample after simulating sunlight with the standard color sample, and it is divided into 8 grades, 8 is the best result, and 1 is the worst. Fabrics with poor light fastness should not be exposed to the sun for a long time, and should be placed in a ventilated place to dry in the shade. GESTER Instruments: Light Fastness Tester-Room Temperature (Air-Cooled) GT-D02A-1, Water-cooled Light & Weather Fastness Tester GT-3000

Washing fastness

Washing or soaping fastness refers to the degree of color change of dyed fabrics after washing with washing liquid. Usually, the gray graded sample card is used as the evaluation standard, that is, the color difference between the original sample and the faded sample is used for judgment. The washing fastness is divided into 5 grades, grade 5 is the best and grade 1 is the worst. The fabrics with poor washing fastness should be dry-cleaned. If they are wet-washed, the washing conditions should be paid more attention to, such as the washing temperature should not be too high and the time should not be too long. GESTER Instruments: Washing Color Fastness Tester GT-D07

Rub fastness

Friction fastness refers to the degree of fading of dyed fabrics after friction, which can be dry friction and wet friction. The rubbing fastness is evaluated based on the degree of white cloth staining, and it is divided into 5 grades. The larger the value, the better the rubbing fastness. GESTER Instruments: Electronic Crockmeter GT-D04, Manual Crockmeter GT-D05, Rotary vertical crockmeter GT-D45

Perspiration fastness

Perspiration fastness refers to the degree of fading of dyed fabrics after a small amount of perspiration. GESTER Instruments: Perspiration Tester GT-D09

Ironing fastness

Refers to the degree of discoloration or fading of dyed fabrics during ironing.

Sublimation fastness

Refers to the degree of sublimation of dyed fabrics during storage. The dye fastness of normal fabrics generally requires 3-4 grades to meet the needs of wearing. GESTER Instruments: Sublimation Fastness Tester GT-D03