Polyester fibers belong to hydrophobic fibers. They lack groups that can bind to dyes. They can not be dyed with water-soluble dyes. They can only be dyed with non-ionic disperse dyes with small molecular weight, no strong ionic water-soluble groups and low solubility. Polyester fibers are compact in structure and boiling dyeing at atmospheric pressure. Dyes are difficult to diffuse into the fibers and dye the fibers thoroughly. Therefore, high temperature and high pressure dyeing machine is used for dyeing.

Disperse dyes are easy to recrystallize because of repeated heating and cooling in high temperature cylinder. The crystals are attached to cylinder wall and filter screen cover, resulting in poor friction fastness of dyes and even blocking the filter of high temperature and high pressure dyeing machine. Therefore, the dyeing cylinder needs to be washed with high-pressure water gun once a month, and the screen cover must be removed every 24 hours.

Oil spots or color spots sometimes occur on polyester fabrics. One of the reasons is that the washing and maintenance of dyeing vats are not enough. Tar-like fabrics in dyeing VATS stick to the fabrics and form tar-like oil spots which are very difficult to remove. The falling of tar-like fabrics causes color spots.

In addition, when the dyeing machine changes to light color after dark dyeing, it also needs to brush the dyeing cylinder. When brushing, all the valves of the pipes are opened to make the liquid of the brushing cylinder unblocked, and high temperature sewage is discharged after heat preservation. In the production of polyester whitening, light color cylinder is used and washed. If the original red cylinder is dyed by the red group, the blue group should be gradually lightened and then whitened. Otherwise, the whitened fabric produced has poor whiteness and red light, even if it is washed 2-3 times continuously before the whitening variety is produced. The cylinder with serious contamination can also be cleaned by a detergent consisting of highly permeable macromolecule detergent, hydrogen peroxide, ammonium hydrogen fluoride, oxalic acid and organic acid corrosion inhibitor, depending on the contamination situation.

Jingjiang Huaxia Technology Co., Ltd

——Specializing in the production of different kinds of dyeing machine.