PU is actually in the performance of polyurethane, mainly for wear resistance, solvent resistance and low temperature resistance ( 30 DEG C), waterproof and moisture permeability good, windproof, soft features, under normal circumstances is milk white emulsion, and the knitting cloth, plain cloth, non-woven fabric composite made of various fabrics or lining, and a variety of the different properties of the films can be two layers or more than three layers of composite processing. We usually contact is generally thin coating of PU leather products mainly used for outdoor clothing and fabrics PU coating, such as; imitation leather (leather ), brushed suede and other products is the PU coating products. PU polyurethane coating can be formed by a lot of multi function, high value-added textile products, widely used in clothing, decoration, military and other industries.

PU coating the paint form, simply and can be divided into water type and solvent type polyurethane. Solvent type film-forming properties, the fabric with strong adhesion, high water pressure resistance, is more suitable for the waterproof breathable coating. But the solvent type have certain toxic and flammable, not environmental protection, water type safe non-toxic, environmentally friendly, but the fabric with poor adhesive force, water resistance performance than solvent based some of the weak.

PU coating agent is made of hard and soft segment part two repeated alternating block polymer comprising. Soft segment PU soft and elastic, by polyether or polyester glycol composition, its molecular size, may also influence the PU degree; hard segment that PU has the strength and modulus of elasticity, by all sorts of diisocyanate and chain extender. The ratio between the two and raw material structure may determine and affect the product performance.

Synthesis method in general by the diisocyanate, polyester glycol or polyether glycol and chain extension agent and catalyst, bulk polymerization or made by solution polymerization. Large granular or powdery available bulk polymerization. Emulsion used emulsifier or introducing hydrophilic groups from a milk two methods. Solvent type used in accordance with the needs of different organic solvents.

Coating process with dry, wet, hot melt method, transferring method, bonding method, in which dry for most applications, dry is the coating slurry applicator for uniformly coated on the base cloth, upon heating the solvent or water evaporation, coating on the surface of the fabric is formed of thin film, PU thin coating is dry direct coating in the high-end products, mainly used for clothing.