pvp textile printing and dyeing industry application

Due to the lactam structure in PVP molecules, there is a strong binding force between hydroxyl, amino, and carboxylic groups, and dyes often contain these functional groups, so PVP and general organic dyes have a strong affinity, and sometimes this affinity even exceeds the binding force of dyes and fibers, so PVP is known as “liquid fiber”. Using this property of PVP can increase the affinity between some hydrophobic fibers and dyes, and then improve the dyeability of such fibers, for example, in the synthetic fiber process, the appropriate amount of PVP is mixed into it, so that the synthetic fiber can be evenly dyed, and improve the coloring power and improve the dyeing depth

Dyeing more difficult polypropylene fiber, in which the incorporation of about 7.5% of NVP/ styrene copolymer, can make the fiber dyeing depth of acid dyes increased by about 10 times, the dispersive dye can be increased by about 5 times. In the process of mixing PVP, it can be evenly distributed in the fiber, which can greatly reduce the color difference of the dyed fabric and improve the adhesion of the dye on the fabric. The textile dyes with uniform color, light resistance and heat resistance are obtained.

In addition to improving the dyeability of some fibers, PVP can also improve its hygeability, sun protection and other properties, greatly improve the quality and grade of synthetic fibers, such as polyamide fiber, polyester fiber and other synthetic fibers with high strength, high fineness, friction resistance, thermal plasticity and good luster and bright dyeing and popular, but hygeability is worse than natural fibers. As a result, it is often used as clothing to attach a layer of water vapor from the air on the surface of the clothing and affect the comfort of wearing, especially in the summer hot and humid weather, poor moisture absorption clothing is easy to be soaked by sweat or high humidity air and close to the skin, and even irritating to the skin. One way to solve this problem is to add 4%-8% PVP to melted polyamide before spinning, and then melt spinning in a low-oxygen environment, the added PVPK value is between 30-70, in which the residual monomer content needs to be less than 0.1%. In this way, the synthetic fibers such as polyamide fiber and polyester fiber have high moisture absorption, washing resistance and thermal plasticity, and as mentioned above, the addition of PVP can also improve some dyeing properties, and control the spinning speed can obtain fibers of different fineness. It is worth mentioning that if the added PVPK value is less than 30, due to the poor complexation ability of low molecular weight PVP and polyamide, there will be some PVP dissolved in water in the water treatment process and not get high hygroscopic fiber. On the other hand, if the molecular weight of PVP is greater than 70, the viscosity of the melting system increases during spinning, making spinning difficult and affecting the production efficiency, and the molecular weight of PVP is too large, the obtained fiber hardness is too large, and can not meet the soft and comfortable requirements of the table fiber. The moisture absorption rate of polyester fiber improved by PVP-K60 can reach up to 20% of the weight of the fiber itself.
Note:

(1) Yellowness refers to the yellowness of the fiber without dye after spinning with PVP, and less than 10 is qualified.

(2) There are two factors that lead to low production efficiency: one is the increase of PVP dissolution rate, and the other is the slow silk production speed.

(3) The dissolution rate data in the table is the dissolution rate of PVP when the synthetic fiber is treated in boiling water for 30 minutes.

The binding ability of PVP and different dyes is different. Using this property, PVP can be used as local anti-dye agent to obtain bright patterns when printing polyamide fiber and polypropylene fiber.

Printed fabric with a clear outline. In the production process of printed fabric, the fabric after printing, but also after washing desizing, in order to wash the unfixed dye and paste and other printing and dyeing auxilaries, to get printed fabric products, in order to achieve the purpose of desizing without staining pattern, to ensure the quality of products, the choice of cleaning agent is very important, research shows that, The cleaning agent used in printing and dyeing industry with PVP and sodium aluminate silicate as the main components has significantly higher cleaning capacity than the cleaning agent without PVP, and can prevent the transfer of color or white dirt in the cleaning process.