Printing synthetic fabric with disperse dyes

Synthetic fabric can't be printed by other dyes than disperse dyes.

1. Printing on polyester fabric with disperses dye: Pre treatment of fabric: Scouring, washing. In printing polyester, the printing paste may be prepared as follows: a) For high pressure steaming: Recipe: 50-100 g Disperse dye (liquid form) 50-104 g water 894 to 790 Thickening (guar gum) 5g Ammonium sulphate 1 gm sodium chlorate (oxidizing agent) 1 kg Printing with disperse dye

2. b) For thermal fixation: Recipe: 50-100 g disperse dye (liquid form) 50-100g water 10-20g Ekaline F1 liquid (carrier) 890-780g Thickening 1 kg

3. Function of ingredients: Sodium chlorate  Oxidizing agent. It protects the brightness of the dyestuff against any possible reduction of the dyestuff under the prolonged steaming conditions at elevated temp. Ammonium sulphate  Used as an acid liberating agent so that the print paste remains acidic (P H =5) during steaming. Ekaline F1 is the carrier used to improve the colour yield.

4. I ) High Temperature steaming: In this system, the steam is raised to about 180 c at atmospheric pressure by bringing steam in contact with radiator. These radiator or the inside walls or ceiling of the steamer are maintained at this high temp (200 c) either by pressure steam or oil heating system. Disperse dyes are fixed in these steamers at 180 c in 1-2 min This is a continuous process and gives full colour yield and bright prints. Fixation: High temperature steaming (super heated steaming) Thermofixation

5. II ) Thermo fixation: Disperse dyes on polyester fabrics can be fixed by subjecting them to hot air at 210 c for about 30 sec The thermo fixation is carried out on a stenter or a baking m/c where heat setting and thermo fixation can be carried simultaneously Prints obtained by themofixation are not as bright as steam. 10-15% loss of colour yield results in the fixation Only dyes with high sublimation fastness should be selected.