Process Of Shrink Proof Finishing And Crease Resistant Finishing Of Knitted Fabrics

Shrink proof finishing.

The water-soluble thermal reaction polyurethane has excellent compatibility with most anionic auxiliaries. It is mainly used in non chlorinated polymers "one-step" wool "addition" shrink proof processing, which saves labor and time, damages the wool and avoids the discharge of harmful substances.

If it is used in conjunction with a suitable amount of polyurethane emulsion or hydroxyl / amino silicone milk, it can be kept to the maximum.

The original style and feel.

Nowadays, waterborne polyurethane wool shrink proof agent has been recommended by the international wool board (IWS).

Many wool mills in China are using Bayer's SynthappretBAP and Japan's Daiqi's ElastronBAP wool shrink proofing agent.

BAP wool shrink resistant finishing agent is a water-soluble thermal reaction polyurethane sulfonate ester. Its synthesis method is to polymerized oligomers with three hydroxymethylpropane and propylene oxide under catalytic conditions, then react with excess 5%~10% isocyanate (HDI), and obtain polyurethane prepolymer with isocyanate terminated. Finally, it is blocked by sodium pyrosulphate in mixed solvents of lower alcohols and water and [22]. is obtained.

BAP is a three functional branched structure, which can be tightly coated under the alkaline condition by heating the netted polymer film. In addition, the -NCO in its molecule can react with -OH, -NH2 and -SH on the surface of wool fiber, and form a strong chemical bond between the polymer film and wool fiber dimension, so that the shrink proof effect of wool fabric is more durable and washable.

Polyether type terminated by Sodium Bisulfite or sodium pyrosulfite

The prepolymer wool shrink proofing agent has good film forming and dispersing property, small surface tension and stable storage. It can reduce the shrinkage rate of wool fabric by more than 90%~95% (standard IWSTMNO.31 for anti felting, and the area shrinkage rate of woollen fabric should be less than 6%), which fully meets the IWS machine washable standard.

The treated wool fabric has soft touch and only slight changes in color, and has a more obvious effect on light colored fabric. [26].

The reaction of silyl propyl polysiloxane with isocyanate groups in polyether polyols and HDI prepolymer was used to produce PU prepolymer containing siloxane, then blocked and dispersed in water by NaHSO3.

This silicone modified thermal reaction waterborne polyurethane wool shrink proofing agent has a superior hand feel than ordinary water-soluble capped polyurethane.

Anti pilling finishing.

Polyurethane has strong film-forming property on the surface of the fabric, and is strong and tough, low temperature resistance, brittle resistance, friction resistance, high strength, good elasticity and certain affinity.

The fabric can improve the cohesion of the fiber, reduce the yarn hairiness and the generation and accumulation of the static charge, which is beneficial to the improvement of the fabric's anti fuzzing and sphericity.

The surface pilling resistance of pure cotton knitted fabric treated with waterborne polyurethane increased from 1~2 to more than 4. No free formaldehyde was released from the finished fabric.

It can not only reduce the production of formaldehyde from the upper part of the fabric, but also effectively prevent the production of woolen balls from the synthetic fiber fabric with its modified 2D resin.

ElastronBAP water dispersible polyurethane not only can be used in wool anti felting processing, but also helps to improve wool fabric's anti pilling properties.

Crease resistant finish.

Water soluble thermal reactive polyurethane can significantly improve the wrinkle recovery angle of cotton fabric.

It can obtain soft, wearable and crease resistant properties.

In the non iron finishing of all cotton thin fabric, water soluble polyurethane crosslinking agent and resin can be combined to ensure fabric strength and improve its crease resistance.

Lignin polyurethane prepared by reaction of hydroxyethyl lignosulfonate (HELS) with aromatic isocyanate can significantly improve the iron press free properties of cotton fabrics.