Basic dyeing knowledge of blended fabrics

Blended fabric is a kind of textile product made of chemical fiber other natural fibers such as cotton wool, silk, hemp, etc. it has the style of polyester the advantages of cotton fabric, such as polyester cotton, polyester wool Huada, etc. Blending is divided into wool viscose blending, rabbit goat hair piping spinning, TR fabric, high-density NC fabric, 3M waterproof mousse fabric, Tencel fabric, rose, TNC fabric, composite fabric, etc.

For example, polyester cotton blended fabric is made of polyester as the main component, which is woven 65% - 67% polyester 33% - 35% cotton blended yarn. Polyester cotton cloth is commonly known as cotton is cool.

This paper briefly introduces the dyeing of synthetic fiber blended knitted fabric

1、 Dyeing methods precautions of blended knitted fabrics

1. Blended knitwear: that is, the knitwear that is spun with two more different fibers then knitted.

1.1 interwoven knitted fabric: refers to the knitted fabric made of two kinds of yarns (different fibers) two kinds of filament interwoven.

1.2 polychromatic effect: in the dyeing of blended knitted fabrics, different colors are required.

1.3 white effect: one fiber is required to be dyed while the other fiber is required to avoid dyeing.

2. Dyeing method of mixed yarn knitted fabric

2.1 one step in the same bath: one two dyes with different properties are used to dye different fibers at the same time in the same bath.

2.2 two steps in the same bath: first dye one kind of fiber with one dye, then add another dye in the bath, use another process to overprint another fiber. In this method, the residue of one step dyeing is required to have no adverse effect on the second step dyeing.

2.3 two bath two-step method: first, dye a fiber in a dye preparation bath, then empty the residual bath, then prepare a second bath for the second fiber dyeing.

2.4 the dyeing method to be adopted shall be determined according to the fiber composition, property blending ratio in the blended fabric, as well as the type performance of optional dyes auxiliaries, dyeing depth product quality requirements.

3. Notes on dyeing of blended interwoven fabrics

3.1 the selection principle of dyes is;

a. Whether the chromogenic effect, dye uptake rate, dye saturation fastness of a dye in different fibers are similar.

b. In case of two types of dyes, the following points shall be noted:

① Prevent precipitation, (cation acid dyes, add anti sedimentation agent)

② Prevent contamination (e.g. dyeing of polyester nitrile interwoven fabric in one bath)

③ Similar fastness

3.2 dyeing temperature: the dye selected in one bath one-step dyeing is similar to the curve of dyeing rate at elevated temperature.

3.3 dyeing pH value

3.4 effect of additives

2、 Dyeing process of synthetic fiber blended interwoven knitted fabric

1. Dyeing of polyester cotton knitted fabric

1.1 disperse dyes, reactive dyes direct dyes are dyed in one step in the same bath, carriers are added in the dyeing bath to dye polyester with disperse dyes. This method has poor fastness.

1.2 in actual production, two bath dyeing is often used. The two bath method is to dye polyester with high temperature high pressure, then use reactive dyes to dye cotton in another bath. In order to make the dyeing bright, the disperse dyes on cotton fiber can be removed by reducing cleaning after one bath. However, the fixation of reactive dyes must be carried out in an alkaline bath, which often affects the shade color depth of disperse dyes.

2. Dyeing of polyester nitrile blended yarn interwoven knitted fabric

2.1 it is allowed to use disperse dyes dye in one step in the same bath, because there are too many differences in dye uptake color matching is more difficult.

2.2 disperse dyes cationic dyes are dyed in one bath one step with Ilex oil as carrier. The disadvantage is that acrylic fiber is easy to shrink cationic dye precipitates easily with the dispersant in disperse dye.

2.3 the same bath two-step method two bath method shall be used for dyeing. Polyester should be dyed with high temperature high pressure, then acrylic fibers should be dyed with cationic dyes in the second bath. Soften. Polyester must be completely reduced cleaned after dyeing, otherwise cationic dye will affect the rubbing fastness.

2.4 dyeing of polyester nylon knitted fabric. When dyeing the same color, attention should be paid to disperse dyes, which may show different colors on different fibers.

2.5 for most products dyed with nitrile cotton blended yarn interwoven knitted fabric, as long as acrylic fiber is dyed instead of cotton fiber, it is a white product. At this time, disperse dye can be used for light color cation dye can be used for dark color, cleaning can be strengthened if cotton quilt is stained. Sometimes in order to improve the brightness of the product, the cotton can be bleached first then dyed. If double dyeing, cotton should be dyed first then acrylic.