Water based polyurethane dispersion for textile application

Waterborne polyurethane is widely used in textile printing and dyeing, such as dyeing, printing binder, coatings and  fabric surface treatment agent like anti-wrinkle, anti-felting and anti-pilling etc. Waterborne polyurethane conforms to the processing requirements of ecological textiles and is widely used in functional finishing of textiles to improve the added value of products.

（1）Fabric surface coating and printing application

Waterborne polyurethane has the characteristics of low temperature flexibility, high elasticity and high adhesion, which can give the coated fabric soft and plump hand feeling, abrasion resistance and high elasticity.In addition, through the design of the molecular structure of waterborne polyurethane or the common application of other functional AIDS, the coating fabric can also be endowed with waterproof and moisture permeable, shape memory, oil-proof, anti-fouling, anti-static, anti-ultraviolet, flame retardant and other properties, or even unexpected effects.Therefore, although waterborne polyurethane still has some shortcomings, it has developed into a widely used finishing agent for textile coating.

（2）Wool fabric anti - felting finish application

The height of the directional friction effect of wool fiber and fiber tensile recovery resulted in the anti-felting of wool fabric, using water-based polyurethane for wool fabric finishing, the polymer film forming, filling scale layer in the surface of fiber, fiber limited slip, scales wrapped passivation, the directional friction effect is abate, give the fabric anti felting performance.Compared with chlorine anti-felting treatment, WPU finishing has the advantages of less fiber damage, simple operation and no pollution.Waterborne polyurethane has received more research and attention in the anti-shrinkage finishing of wool fabrics. Epoxy resin and organosilicone modified cationic WPU are used in the finishing of fabrics, with excellent anti-shrinkage effect, soft hand feeling and low yellowing index.

（3）Anti-pilling finishing application

During wearing and washing, the garment is subjected to tension and friction, which causes the position of the fiber in the fabric to slip, resulting in the fiber tip protruding from the fabric surface. This part of the fiber is entangled with each other, resulting in the pilling of the fabric.Due to the characteristics of fiber and fabric structure, the pilling of chemical fiber, wool and cashmere and their blended knitted fabrics is relatively serious.Using resin to cross-link the fiber surface to form a film can limit the slippage of the fiber in the fabric, and make the fiber end adhere to the yarn to reduce the pilling.Waterborne polyurethane has excellent mechanical properties and high adhesion, and has attracted extensive attention in anti-pilling finishing.

（4）Anti-wrinkle finishing application

When the fabric is subjected to the external force, the fiber will undergo tensile deformation and compression deformation, which will lead to the deformation of the fiber.Waterborne polyurethane has excellent film-forming and elasticity. Waterborne polyurethane is adopted to treat the fabric, and the fiber surface is wrapped by elastic waterborne polyurethane film, which can increase the elastic modulus of the fiber and enhance the anti-deformation ability.Therefore, waterborne polyurethane can be used as an anti-wrinkle finishing agent for fabrics. Compared with urea-formaldehyde anti-wrinkle resin, waterborne polyurethane has the advantage of being formaldehyde-free.