Preparation of proofing gray fabric
1. Keeping the cloth used for small samples and large samples consistent is the basic condition for improving the accuracy of small samples.
For pure cotton fabrics, due to different varieties, origins or maturity of cotton fibers, different warp and weft densities and tissue specifications of the fabrics, as well as different pre-treatment methods and pre-treatment levels of the fabrics , will cause different effects. For chemical fiber fabrics and blended fabrics, such as pure polyester or polyester-cotton, polyester-viscose and other blended fabrics, due to the different raw materials and process operations used in making synthetic fibers, differences in fiber microstructure will directly result in different manufacturers and different brands. Polyesters with different batch numbers and specifications have different color absorption properties when dyed.
In view of the above and many other factors, when selecting gray fabric for proofing, the semi-finished gray fabric used for large-scale production must be used. If proofing is made in advance, the semi-finished gray cloth used for large-scale production will not be available in time. Then you can use a similar semi-finished gray cloth to make a preliminary sample, and find out the basic material prescription in advance. After the semi-finished gray cloth used for large-scale production comes out, you can then make a duplicate sample. If it does not match the standard color light, you need to adjust the materials until Until the duplicate sample matches the village sample. To sum up, only by ensuring that the cloth used for small and large samples is consistent can we avoid differences in large and small samples due to differences in fiber quality, blending ratio, tissue specifications, whiteness, gloss, moisture absorption properties, etc., and improve the accuracy of small and large samples.
2. Requirements for gray fabric pre-treatment are based on the dyeing color and dyeing materials:
Due to the different depth and brightness of the dyeing color, the requirements for gray fabric processing are also different, for example, reactive dyes The light and bright color dyeing requires careful bleaching of the gray fabric to make it have better whiteness and hair effect; for dark and dark colors, semi-bleaching or no bleaching can be carried out.
In addition, because some dyes have special properties, they also put forward some special requirements for the pre-treatment process. For example: when dyeing with reactive dyes, since the dyes are reactive dyes and are relatively sensitive to the chemical environment they come into contact with, the following pre-treatment of gray fabrics is required:
1) Boiling and bleaching must be even and thorough , to avoid the waste of reactive dyes;
2) Do not bring chlorine. Most reactive dyes have poor resistance to chlorine bleaching. If there are residual chlorine or bleach stains on the cloth, It will destroy most reactive dyes and make the dyeing lighter and darker;
3) The cloth surface appears neutral after pre-treatment. Because the cloth surface contains alkali, it is easy to cause uneven dyeing. The acid content on the cloth surface will affect the dye and make it light in color. The pre-treatment has a good capillary effect. The pH value of the cloth surface is uniform, with a PH value of 6~7.
In short, the quality of the gray fabric used for dyeing and the selection of pre-treatment processes all have an impact on the dyeing proofing and dyeing quality. It has a certain influence, so the preparation of gray fabric before dyeing and proofing is an important task that cannot be ignored. </p
