Color fastness generally refers to the resistance of textile color to various effects during processing and use. Then the fastness grade is evaluated according to the discoloration of the sample and the contamination of the undyed lining fabric. The color fastness test of textiles is a routine inspection item in the internal quality inspection of textiles. Let's take a look at the principle of color fastness test. Simply put, the textile crystal sample is attached to one or two designated lining fabrics and is in close contact with the intermediate heated to the required temperature. Then use the gray sample card to evaluate the discoloration of the sample and the staining of the interlining, and then evaluate the fastness grade according to the discoloration of the sample and the staining of the undyed interlining.
The fading degree of dyed and printed fabrics under the action of external factors (extrusion, friction, washing, rain, exposure, seawater immersion, saliva immersion, water stain, sweat stain, ironing, chemicals, etc.). ) is an important index of fabric. However, because the conditions and requirements of fabrics in the process of processing and use are very different, most of the testing methods are simulated testing or comprehensive testing according to the production environment and conditions, so the testing methods of dyeing fastness are quite extensive.
Some printed and dyed textiles have also undergone special finishing, such as resin finishing, flame retardant finishing, sand washing and sanding. This requires the color of printed and dyed textiles to maintain a certain fastness. The color fastness is directly related to human health and safety. When products with poor color fastness encounter rain and sweat, the pigment on the fabric will fall off and fade. Among them, dye molecules and heavy metal ions may be absorbed by human body through skin, which is harmful to human health. On the other hand, it will stain other clothes worn on the body, or stain other clothes when washing with other clothes. These are very common in life. For example, if you wash a dress with poor color fastness and put it with other clothes, then these clothes may be scrapped.
The color fastness of fabric is related to fiber type, yarn structure, fabric structure, printing and dyeing method, dye type and external force. The test of color fastness generally includes color fastness to light, color fastness to weather, color fastness to washing, color fastness to rubbing and color fastness to perspiration. Sometimes there are some special requirements for color fastness according to different textiles or different use environments. Usually, the color fastness test is the degree of discoloration of the dye and the degree of staining to the lining. The color fastness grade is five, except that the light fastness is eight. The higher the grade, the better the color fastness.
Looking at many standards of ISO, AATCC, JIS in Japan and BS in Britain, the most commonly used ones are washing resistance, light resistance, friction resistance and perspiration resistance, ironing resistance and weather resistance. In practical work, the test items are mainly determined according to the end use and product standards. For example, the wool textile product standard stipulates that the color fastness to sunlight must be tested, the color fastness to perspiration should be tested for knitted underwear, and the color fastness to weather should be tested for outdoor textiles (such as umbrellas, light box cloths and canopy materials).
classify
The degree of fabric discoloration can be expressed by color fastness. According to different media causing color change, the color fastness of fabrics includes the following aspects:
1. Colour fastness to washing
Color fastness to washing refers to the degree of color change of dyed fabric after washing or soaping. It is usually judged by the color difference between the original sample and the faded sample. Fabrics with poor color fastness to washing should be dry-cleaned. If it is wet washing, we should pay more attention to washing conditions, such as washing temperature should not be too high and time should not be too long.
2. Colour fastness to sunlight
Color fastness to sunlight refers to the degree of discoloration of fabrics under the action of sunlight. The test method can be natural sunlight or daylight machine, and the fading degree of exposed samples is compared with that of standard color samples. 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.
3. Colour fastness to perspiration
Color fastness to perspiration refers to the degree to which dyed fabrics fade after being soaked in sweat. Clothes with poor color fastness to perspiration are easy to fade under the armpits. Because the composition of artificially prepared sweat is not the same, the color fastness of sweat is generally measured separately, and other color fastness should be combined.
4. Colour fastness to rubbing
Color fastness to rubbing refers to the degree of fading of dyed fabrics after rubbing, which can be divided into dry rubbing and wet rubbing. The service life of fabrics with poor rubbing color fastness will be limited.
5. Colour fastness to ironing
Color fastness to ironing refers to the degree to which dyed fabrics change color or fade during ironing. Appropriate ironing temperature should be selected in clothing production and wearing.
The color fastness of fabric is an important index of fabric wearability. For example, the color fastness to washing not only affects the clothes, but also causes stains on the clothes washed together, so it is one of the key assessment items in textile trade.
Through these brief studies on the color fastness of fabrics, I believe readers will have a general understanding of this proper term and be a rational consumer in life.
Tubatu Online provides you with "every decoration quotation, 1-4 local decoration companies, 3 sets of decoration design schemes" and the decoration pit avoidance strategy for free! Click this link:/Zhu Ye /zxbj-cszy.php? to8to _ from = SEO _ zhidao _ m _ jiare & amp； Wb, you can get it for free ~