Polyester fibers are hydrophobic synthetic fibers that lack functional groups that can be combined with direct dyes, acid dyes, and basic dyes. Although polyester has an ester group that can form hydrogen bonds with disperse dyes, the molecular chain structure of polyester is tight, the dye molecules are not easy to enter the fiber, dyeing is difficult, and the color is monotonous, which directly affects the development of the fiber. The modified polyester product of Lelis is in this situation.

Due to the high crystallinity of polyester, there are only very small voids in the fibers. When the temperature is low, molecular thermal motion changes its position to a lesser extent. In wet conditions, polyester fibers do not pass as vigorously as cotton fibers. Swelling increases voids and makes it difficult for dye molecules to penetrate into the fibers. This is not the case with modified polyester products such as Leris.

It is relatively easy to dye Leris. If it is to dye polyester, it is usually only possible to use disperse dyes for dyeing, and it must be dyed under high temperature and high pressure or with the help of a carrier. Dyeing Leris is not so troublesome. In addition, some other methods can be used to improve the dyeing properties of Leris: (1) copolymerization with bulky compounds; (2) blending spinning with plasticizers; (3) introducing ether bonds and dispersing dyes with harmonious affinity group.

With the development of the synthetic fiber industry, the continuous improvement of people's living standards and the continuous progress of science and technology, people's research on Lelis will be further developed, and the application of modified polyester fabrics and polyester blended fabrics will be increasingly developed. Broadly speaking, there will be further changes in the proportion of residential, decorative and industrial polyesters. The excellent properties of the polyester fabric itself, coupled with the bright colors, good hand feel, anti-pilling, moisture absorption and antistatic properties of modified fabrics like Leris will greatly promote the development of the polyester fiber industry.