NKY® PVP K

NKY® PVP specification models：

Mechanism of action between NKY®PVP and dyes.

Lactam groups in PVP molecules have strong polarity and can form hydrogen bonds with organic functional groups such as hydroxyl, amino and carboxyl groups in dye molecules. The carbonyl group in lactam group also has strong chelating ability, which can chelate with metal atoms in metal complex dyes to achieve the purpose of grabbing dyes. PVP has strong binding ability for reducing, curing, direct and acidic dyes.

PVP grab dye schematic

The role of PVP in textile and dyeing industry.

1 PVP can improve the dyeability of many hydrophobic fibers.

PVP(or its copolymers) is introduced into synthetic fibers by grafting copolymerization, surface grafting, mixed spinning with other synthetic resins, wet spinning fiber impregnation, or coating, etc., so that synthetic fibers can be uniformly dyed and the dyeing depth can be improved.

For example, the fibers made of polypropylene, polyamide, polyvinyl chloride and other materials are not easy to color, and 7.5% to 10% PVP K30 is added to these resins for spinning using acid dyes or dispersive dyes, and the dyeing depth can be increased by 3 to 10 times.

In addition to improving the dyeability of synthetic fibers, PVP can also improve other properties of synthetic fibers. For example, the graft copolymer of PVP and nylon 66 can not only be dyed with acid, direct and VAT dyes, but also improve its hygroscopic property, wrinkle resistance, setting property, easy washable property, strength and sun resistance after bleaching. Another example is the use of 10% PVP mixed viscose fiber, its moisture absorption from 3ml/g, increased to 5 ~ 6ml/g. For example, the copolymer fiber of acrylonitrile and vinyl chloride will produce permeability and loss of light when it meets water or water steam under heat conditions. After adding 3 ~ 5% PVP, the fiber does not have the above phenomenon.

2 PVP is used as levelling agent for acid dyes and metal complex dyes.

   Taking polyamide fiber (nylon) dyeing as an example, PVP has obvious retarding effect on acid dye dyeing on nylon fabric, reduces the initial dyeing rate of dye, slows down the dyeing process, and achieves the purpose of leveling dyeing.

Taking polyester fiber as an example, PVP as a levelling agent, dyed fabric not only uniform color, and the sun fastness from the original 2 to 8, its antistatic property is also greatly increased.

3 PVP is used as a printing anti-stain agent (anti-dye transfer inhibitor).

After the fabric is printed, it should be washed or soap washed to desizing and wash away the unfixed pigment to improve the color fastness and restore the feel. Adding PVP to the soap can prevent excessive stripping of color, and catch free dyes to prevent cross-color and white dirt.

4 PVP is used for fabric finishing.

    In the process of finishing the fabric, the finishing bath composed of 0.1~0.2% PVP, softener, antistatic agent, resin finishing agent and fluorescent whitening agent was used to finish the fabric. The whiteness, fluorescence, softness, electrostatic charge and strength of the treated fabric all reach or exceed the performance index.