Types of disperse dyes and uses

Disperse dyes are far less water soluble dyes that dye polyester and acetate fibers. It is mainly used for the dyeing of polyester fibers. Mostly, the chemical structure of disperse dyes is azo, the percentage is 80% of disperse dye, followed by AQ-about 15%, about 5% of other struct types. Once some scholars believe that the crystal morphology of disperse dyes has an impact on its dyeing properties, but later research denies the claim. Disperse dye Crystal, however different, the lattice energy is different, so crystal form of disperse dyes have an impact on its commercialization process.

There are three commonly used disperse dyes dyeing method: carrier dyeing, high pressure and heat-melt method. The actual temperature of high temperature and pressure is only 130 ℃, the pressure is only 0.2MPa (gauge pressure). The reason why it is called so is because the dyeing of other dyes often carried out under pressure, and dyeing temperature usually are not exceed 100 ℃.

Carrier dyeing is carried out at atmospheric pressure with heating. It uses chemicals that have the immediacy to dyes and fibers. When dyeing, this chemical enters the inside of polyester, dye molecules are also brought into, this chemical called a carrier or carrying agent. Common carriers are o-phenylphenol, such as benzene, Methyl salicylate. Due to most of them are toxic and harmful to the human body, they have been rarely used.

Hot-melt dyeing does not work in water, instead it pads dyeing liquid dye on the fiber surface, put this fiber into the 180~220℃ oven after drying, and stay 30s, dye sublimation during this process and fiber coloring. In accordance with the dyeing process, disperse dyes can be divided into high-temperature, medium temperature and low temperature type. The high temperature disperse dye are the largest molecules and the best sublimation fastness among them.

Disperse dyes in use have new developments: multicomponent disperse dyes, usually mixed according to certain proportion by two disperse dyes; transfer printing, make disperse dye into printing ink, printing on the fabric, and then after high temperature pressing dyeing, this process is also known as non-aqueous printing. It has the advantages of energy-saving, time saving, convenient, easy, etc; the mix use of reactive dyes and disperse dyes make dyeing process simplified, also the quality of printing and dyeing is improved.