The important role of sodium alginate prin paste in printing and dye industry

　　Sodium alginate is an excellent raw material for preparing warp sizing and printing and dyeing paste. Qingdao Nanshan biotechnology sodium alginate factory mainly introduces the important role of sodium alginate printing paste, especially in the printing and dyeing industry, sodium alginate paste has good washability and high debinding rate, and the film formed on the fabric after printing has certain adhesion and flexibility. It does not react with dyes and other auxiliaries, and the film formed after printing can be easily removed in the washing process even after baking or steaming at high temperature, thus making the fabric feel soft.

　　First, reactive dye printing paste

　　Sodium alginate is an ideal paste for reactive dye printing, because there is no functional group in its molecule that reacts with reactive dyes. In the molecular structure of sodium alginate — COONa is negatively charged after ionization in water, so sodium alginate itself is negatively charged. Because the matrix of reactive dyes has negative water-soluble groups such as carboxyl group, sulfonic group and sulfanilamide group, they are ionized in water and have negative charge, so the reactive dyes also have negative charge. The repulsion of static electricity prevents the combination of reactive dyes and sodium alginate paste, and promotes the dye uptake. However, other pastes, such as modified starch and synthetic dragon gum, are not suitable as printing pastes for reactive dyes, because their molecules contain a large number of hydroxyl groups, which are easy to bond with active groups in reactive dyes, resulting in poor fastness, light color, easy infiltration when encountering water droplets, and fading after washing.

　　Second, disperse dye printing paste

　　Disperse dyes are often used in synthetic fiber printing, and sodium alginate as thickener can get excellent printing effect. According to the characteristics that most synthetic fibers are hydrophobic and absorb less printing paste, sodium alginate with low viscosity is usually used to prepare color paste with high solid content, so that dye particles are evenly dispersed in the color paste and the printing effect is improved.

　　Iii. Indirubin dye printing paste

　　Indirubin dyes are used for printing all over the floor, and starch paste is used to prepare printing paste. Because of the poor permeability of starch paste, uneven color feeding often occurs. Using sodium alginate paste to prepare printing paste, and engraving flowers all over the floor for printing, can improve the color uniformity of dyes.

　　Fourth, fast sulfolane dye printing paste

　　Fast sulfoxylate dye is a mixture of chromophenol and chromodiazosulfonate, which is called lacquered or lacquered for short. Generally, alkaline starch paste can be used for color paste. When printing large-area patterns or thin lines, sodium alginate paste is usually used to ensure good permeability, uniform color and smooth lines. Because sodium alginate paste will coagulate when it meets strong acid, triethanolamine needs to be added to increase the stability of color paste and prevent sodium alginate from coagulating.

　　5. Polycondensated Dye Printing Paste

　　The aqueous solution of condensed turquoise blue I5G is negatively charged. When preparing color paste, there is no special requirement for paste, and starch, sodium alginate and synthetic dragon gum can be used. What kind of paste is used depends on its performance with the dye: sodium alginate can be used when matching with reactive dyes, and starch paste or synthetic gum can be used when not matching with reactive dyes.

　　Six, polyester Shilin dye printing paste

　　Polyester Shilin dye is a vat dye, which can color polyester and cotton fibers at the same time. Generally, the two-phase process is adopted, which is first baked to fix the color on polyester fiber, then dipped and reduced, and then quickly steamed to fix the color on cotton fiber. Excellent printing effect can be obtained by using sodium alginate as the original paste.

　　The new printing paste has the following advantages:

　　1, the color yield is high, and the dye is saved. The paste is sticky and smooth, and has good dispersibility, so that the dyed materials can be evenly dispersed and accurately fixed in a certain position of the fabric without bleeding, and the disadvantages of uneven dyeing, color spots, bleeding and broken thin lines that are easy to occur when using the traditional paste are avoided, so that the pattern outline is clear, the color is bright and the dye can be saved.

　　2. High color fastness. The product does not coagulate and hydrolyze in the color paste with PH value between 5 and 13, and has good acid and alkali resistance and electrolyte resistance, and strong carrying capacity, so that the dye can be fixed on the fiber through various functions.

　　3. Improve production efficiency and product quality. The new paste has the advantages of proper viscosity, sticky but non-sticky, and high thixotropy. When the dyed material is carried on the fabric, the color paste prepared by this paste does not stick to printing tools and fabrics, which effectively avoids the disadvantages of traditional paste in the printing process, such as scratching due to the knife edge, dragging due to the screen, and difficult to desize due to the fabric, thus reducing the defective rate and improving the work efficiency and product quality.

　　4. Wide application range. This product is mainly suitable for printing process of reactive dyes and disperse dyes. The dosage of triethanolamine can be reduced by 50% in the use of acid dyes and fast sulforaphane (Layuanlalan) dyes. It can be used in printing processes such as roller, flat screen and rotary screen. Can be used in the printing of pure cotton, flannel, polyester cotton and other fabrics.

　　5, the use method is simple and easy to operate. The paste is used in the same way as sodium alginate, and there is no need to change any process. First, tap water or warm water is put into a bucket, and then the new paste is slowly poured into the water under constant stirring, and fully stirred until it is a paste without granules.

　　Keywords printing, paste, sodium alginate, size, auxiliary agent