Color fastness (Color fastness) is also called dye fastness and dye fastness. It refers to the resistance of the color of textiles to various effects during processing and use.
The fastness grade is evaluated based on the discoloration of the sample and the staining of the undyed backing fabric. Textile color fastness testing is a routine testing item in the intrinsic quality testing of textiles. During their use, textiles are subject to various external effects such as light, washing, ironing, sweat stains, friction, and chemicals. Some printed and dyed textiles also undergo special finishing processes, such as resin finishing, flame retardant finishing, sand washing, and grinding. Wool, etc., which requires the color and luster of printed and dyed textiles to maintain a certain degree of fastness.
Color fastness is referred to as color fastness; the color of colored fibers, fabrics or other colored objects, in The ability to withstand various corrosive effects such as sunlight, washing, friction, sweat, etc. during processing and use.
The color richness ratings are all level 5 except for the lightfastness (fastness to light and aging) which is R level. The higher the grade, the better the color fastness. There are two methods for measuring leather: fading (color change of the leather itself) and staining (contamination of contact objects). The fading test is the color difference between the leather sample and the untreated test sample after the leather sample is processed according to specified conditions, and is graded by comparison with the standard gray sample card. The staining test is to touch the sample with a standard white cloth under specified conditions. The extent to which the white cloth is stained by the color transfer of the sample is determined and graded using a gray staining sample card.
In ready-made garments that are composed of different colored parts, dye migration from one area to another sometimes occurs during storage. , usually migrates from the dark part to the light part. This phenomenon is different from sublimation because it is performed at a temperature lower than the sublimation temperature, and this phenomenon also occurs with non-sublimation dyes. It is mainly reflected in the migration of chemical fiber fabrics such as polyester, but also other raw materials. Color transfer is mainly due to two reasons: First, the dye has transferred, especially the floating color of dispersed and reactive dyes and the free dye migrating within the fiber, which may dye the fiber on the surface of another sample; especially The dark color dyes the light color and remains on the surface of another sample in the form of granules and imprints. The second is that the fibers fell off under the action of friction and were transferred from one sample to another sample.
Color fastness is a type of color fastness, also called color transfer fastness or color fastness. Color fastness to bleeding refers to the migration and staining of dyes or residual floating colors on fabrics. It mainly reflects the contamination caused by the dye dissolving from the dyeing area and migrating to the white or light-colored base fabric after the fabric is washed or rained. The degree comes from Japan, and is also called the “Daimaru method” in the Japanese testing method.
Color fastness has now become one of the common testing items in Japan. It is generally required to reach level 4 or above level 4-5, mainly in medium and dark colors. It is often related to stain fastness. Good stain fastness will result in better color fastness.
One end of the sample is immersed in the water containing the reagent, and the color changes due to the rising effect of the water. The degree of pollution is assessed using the pollution gray card.
Required test materials: balance, beaker, volumetric flask, room temperature dyeing machine
1. Cut a 3cmx2.5cm sample. If all the colors of the patterned fabric cannot be cut into one piece, cut the dark color (the most delicious color).
2. Cut the cotton and white cloth into (length) 20~25cm x (width) 2.5cm.
3. Place the test piece under the cotton-added white cloth, and sew a line on each end where it overlaps 1.5cm. .
4. Prepare the nonionic surfactant solution: Dissolve 0.5g of the nonionic surfactant into 1000ml of distilled water .
5. Immerse one end of the test piece in the test solution to a depth of 2cm, and follow the standard method of each company at room temperature. Leave for 2 hours.
6. Remove the solution and let the test piece dry naturally in its original state.
7. Judgment: Use the JIS stained gray card to rate the sample (white or light-colored parts of the sample Staining).