What are the types of fabric color fastness tests?
The test for color fastness is usually to determine how well it holds its color against light, weather, washing, rubbing, and perspiration. Depending on the type of fabric or where it will be used, there are sometimes special rules about how long the color will last.
Most of the time, when testing color fastness, what matters is how much the dye fades and how much the lining stains. The color fastness is a grade 5, but the light fastness is a grade 8. The color will stay true for longer if the number is higher.
Colorfastness to light.
Most of the time, textiles are exposed to light when they are being used. Light can break down dyes, which makes colored fabrics change color. This is called “fading.” Most of the time, they get lighter or darker, and some even change color. Because of this, you need to test the color fastness. The sun color fastness test involves putting the sample out in the sun under the given conditions along with different grades of blue wool standard cloth and comparing the sample to the blue wool cloth. Check the grade to see how light-resistant the blue wool standard cloth is. The more the grade goes up, the more resistant it is to light.
Washing color fastness
The sample is sewn together with the standard lining fabric, washed, cleaned, and dried, and washed under the right temperature, alkalinity, bleaching, and friction conditions, so the test results can be gotten quickly. A small bath ratio and the right number of stainless steel beads are rolled and hit against them to make them rub together. By marking with a gray card, you can find out how well you did on the test. In the Jiayu test network, the temperature, alkalinity, bleaching, friction, and sample size are all different for each test method. The specific methods of testing should be chosen based on the test standards and the customer’s needs.
Place the sample on the rubbing fastness tester and rub it with a standard rubbing white cloth a certain number of times and with a certain amount of pressure. Each group of samples needs to be tested for both dry and wet rubbing color fastness. With a gray card, the color that gets on the standard friction white cloth is rated, and the grade is the measure of how well the color stays on the cloth. Rub tests for color fastness should be done both dry and wet, and all of the colors on the sample should be rubbed.
Color resistance to dry cleaning
The color fastness is the same as that of water washing, except that water washing is changed to dry cleaning.
Color fastness to perspiration
Sew the sample to the standard lining fabric, treat it with the perspiration solution, clamp it to the perspiration fastness meter, bake it at a constant temperature, let it dry, grade it with the gray card, and you’ll have the results of the test. Different test methods use different amounts of perspiration, different sample sizes, and different test temperatures and times.
Color fastness to non-chlorine bleaching
The color fastness of non-chlorine bleaching is to evaluate the color change of the fabric after it is washed under the washing condition of non-chlorine bleaching.
After covering the dry sample with cotton lining fabric, put it in the heating device at the specified temperature and pressure for a set amount of time. Then, use the gray sample card to judge the discoloration of the sample and the staining of the lining fabric. When it comes to color fastness, dry pressing, wet pressing, and wet pressing all count. The test method should be chosen based on the needs of the customer and the test standards.
How to use a dry and wet color fastness test?
Both the dry and wet color fastness tests are used a lot in the textile industry to check how well colors don’t run when they get wet or dry. In the textile instrument industry, there are different kinds of wet and dry color fastness cylinders. The electric dry-wet method and the manual dry-wet method are the most common ways to test for color fastness.
Test for dry fastness
- Place the sandpaper on the base of the tester along the length of the sample. Then place the test sample on sandpaper.
- Place the sample rack on top of the sample to keep it from sliding.
- Place a square friction cloth on the friction head in the downward direction. The walking direction of cloth rubbing is parallel to the direction of cloth rubbing, and it is covered with a special ring. Please note that the ring should not be too low as this will drag the test sample.
- Lower the friction head so that it contacts the sample. The starting position is placed in front of the friction head test route. Shake the handle back and forth 10 times at the speed of one return per second. In this way, the friction head will be repeated 20 times in the sample. For the electric cylinder, set it 10 times and start the tester. For other return times, see requirements.
- Remove the wiping cloth, humidify it according to the standard (AATCC), and then compare the gray scale to the standard dyeing method. For wool, fluff, and abrasive samples, the grade will be affected once some loose fibers are contacted on the wiping cloth. Before grading, gently press the cloth with sandpaper to contact irrelevant short fibers.
Wet fastness test
- Thoroughly wet the cloth with distilled water.
- Before the test, please use simple methods, such as clamping the wiping cloth between the filter paper and rolling it with a mill, so as to control the moisture content at 65% 5%. The calculated moisture content is based on the wet weight of dry cloth under standard atmospheric conditions (temperature: 21 °C, humidity: 65%).
- Perform the dry fastness test described above.
What is color fastness?
Color fastness means that the color of a textile doesn’t change when it’s used or processed in different ways. The fastness grade is based on how much the sample has changed color and how much the uncolored lining fabric has been stained. The test for how well a fabric keeps its color is a standard part of textile quality tests.
What are the aspects of color fastness?
Soaping fastness, rubbing fastness, chlorine water fastness, non-chlorine bleaching fastness, dry cleaning fastness, actual washing fastness (for clothes and fabrics), sweat stain fastness, water fastness, light fastness, sea water fastness, saliva fastness, etc. are all common types of color fastness.
How is the color fastness rated?
Color-fastness requirements vary depending on how the dyed product will be used. In the simulation experiment, the color change of the sample before and after the experiment is compared with the standard sample card to get the color fastness grade. There are five levels of how well something holds up to soap, rubbing, and sweat. The first level is the worst, and the fifth level is the best. There are eight grades of sun fastness and climate fastness, with grade one being the worst and grade eight being the best.
What is the highest color fastness of cotton cloth?
Cotton fabric is usually dyed with reactive dyes. For first-class products, the color fastness to dry and wet rubbing is higher than grade 4 and higher than grade 3 for wet products. The color fastness to washing, discoloration, and stains is also higher than grade 4. Most fabrics dyed with reactive dye can keep their color up to grade 3.5, and most fabrics dyed with reactive dye can keep their color up to grade 2.5.
In general, green or bright blue can only get to level 3, bright red can get to level 3.5, and other colors can get to level 4. At the moment, these are the most reactive dyes, and the way they are used and the additives that go with them are fairly complete and well-developed. This makes it possible to treat general color fastness in a very good way.
For example, reactive dyes usually don’t stand up well to chlorine bleaching, and blue dyes with an anthraquinonoid structure tend to fade when exposed to smoke. These problems can be fixed with additives, but the costs vary. By the way, if you want to dye light-colored varieties, most cotton fabrics use expensive vat dyes because the light fastness (above grade 4) mostly depends on the dye itself, and the additives and processes are hard to improve or limit.
What does “self-staining fastness” mean?
Self-staining color fastness is when a sample has more than one color and the depth of each color is different. If the sample or piece of clothing can easily come into contact with its own depth, like when it is washed, the dark color may stain the light color. Take the dark and light parts of the fabric directly from the fabric, stick and sew them together to make a combined sample, and then run the required test procedure. The light color staining is the main thing that affects the rating.
What is the difference between color fastness in water and color fastness in washing?
The color’s resistance to water is its resistance to being immersed in water. Stick the fabric sample to the specified lining fabric, put it in water, squeeze out the water, put it between two plates, and apply a certain amount of pressure. After the sample and lining are dry, use the gray sample card to see how the sample has changed color and how the lining is stained. Color fastness to soaping is another name for color fastness to washing.
The fabric sample is sewn together with the specified lining fabric and put in the soap solution or a mixture of soap and anhydrous sodium carbonate. After a specific washing procedure in the washing color fastness testing machine, after cleaning and drying, and using the original sample as a guide, the discoloration and lining staining of the sample are measured with a gray sample card or instrument. The first one just needs to sit in water, while the second one needs to be washed with soap.
What is color fastness and the difference between the two?
Color fastness refers to the ability of a dye to maintain its natural color. Verify in the environment of light, cold and heat cycles, chemical reagents, etc. Color fastness is the ability of dyes to transfer and adhere to other materials. It is verified under the experimental environment of a hundred grid tests, dry friction, chemical reagents, sweat, and so on. The number of specific test items increases or decreases based on the product’s performance requirements and the working environment where it is used.
Is the color fastness of labels on clothing products the greater the better or the smaller the better?
The greater the color fastness, the less likely it is to fade during cleaning. For the washing of ready-made clothes, color fastness is the firmness of the color. The larger the color, the less likely it is to fade.
What are the methods of the leather rubbing color fastness tester?
The leather rubbing color fastness tester/testing machine, which is used to check how well leather surfaces hold their colors after being rubbed, the color transfer is judged by how much the leather surface or coating “fades” and how much the wool felt gets stained. During the test, white wool felt, either dry or wet, is wrapped around the friction surface, and the test piece is rubbed back and forth on the test bench. There are two ways to test: in the dry and in the wet.
What color fastness should be considered when choosing zippers?
When choosing zippers for clothing, we should not only pay attention to the color difference between the zipper cloth belt and the fabric, which is well known, but also to how well the zipper cloth belt keeps its color. For manufacturers, it’s still not clear if zippers meet the standard for color fastness and if the difference in color between the zipper and the clothing will affect the quality of the final product. Color fastness is mostly about how well a product holds up to washing and friction, which is mostly what the friction color fastness tester checks.
Manufacturers of zippers should not only pay attention to color when choosing zippers, but they should also think about three types of color fastness. Not only does clothing with zippers pay attention to the color and material of zipper cloth, which is usually specified by zipper manufacturers, but it also pays attention to how well zipper cloth holds its color. As a manufacturer, when choosing zipper suppliers, we should mainly think about three kinds of zipper color fastness: sun fastness, soaping fastness, and color dye transfer to improve clothing quality.