Polyester fiber is used more than any other material for car seats. When printing deep color motifs on a pale color ground, direct printing is carried out, however, if the ground color is mid-dark, the motifs should be colored discharged (alkali discharged) after ground dyeing. (Table 5)

Table 5 Treatments for polyester car seats

[Setting for direct printing]

Fixing with HT-steaming or thermosol is possible without drying after printing, however, the sharpness of motif-outlines becomes weak compared with cases in which drying has been carried out. For a stock paste, in consideration of sharpness and color development, adding CMC and CMS at the proper time to a base of sodium alginate with good paste removing properties is recommended.

[Setting for padding for discharge ground color]

The padding solution should have higher viscosity (600-1,000 cps) than usual, and the pickup after padding should be set around 85% (weight of cloth: 350g/m²). A silicon type antifoaming agent is usually used to eliminate bubbles (foam from disperse dyestuffs and penetrating agents) occurring in the padding solution, however, with antifoaming agents made of large silicon particles the agglomeration of disperse dyestuffs easily occurs. An antifoaming agent for printing (printing oil) is effective when using padding solution with high viscosity. Senkaemulsyn 300, which softens the hand of padded-dry cloth, is also effective for leveling and accelerating the fixation of dyestuffs.

[Recipe for alkali discharge paste]

[Recipe for stock paste for discharge printing]

For an alkali discharge paste, it is important to choose thickeners with stable viscosity since a large amount of a solubilization accelerator (GTG-01 from Senka) and an alkali agent are used. GCN-15 is compatible with discharge chemicals and a compounded thickener that leads to a high discharge effect, and furthermore a stock paste with good printability (transferring / penetrating carried out evenly on padded cloth and neither splashes nor cracks of paste occur on account of its soft dried film) can be prepared by adding Primogum F-30.For dyestuff fixing, HT-steaming
(175, 8 mins.) is the most suitable procedure when only the discharge effect of it is considered. Thermosol (190, 4mins.) can be applied as well, and GTP-31 or Emulsyn T-57 can be added as a dye / discharge accelerator for dyestuffs.

(* Shanghai Daxiang Chemical Industry Co., Ltd.• Senka Corporation)