Automatic Double Twisting Stripping Machine

automatic double twisting stripping machine

Basic Info

Product Description

High quality yarn

The winch roller driven single spindle,more accurate yarn twist,no external force extrusion,more rounded cross section;

First twist,compound twist through computer control,touch screen easy to operate;

On spindle speed computer tracking display,ensure accurate initial compound twist;

No oil imported materials of high speed steel making,reduce yarn breakage;

NC constant tension winding,ensure the constant line speed,volume weight up to 1.6kg;

Twist C.V≤1.5%,meet the requirements of the highest quality yarn.

Ply count range:

2×1: 50D—500D

3×1: 50D—1000D

Products apply for sewing,embroidery,bonded thread.

Dyeing unevenness, recrystallization, agglomeration and focus

1. Uneven dyeing

The uniformity of dye absorption is related to the ratio of dye flow rate and absorbance. In the color absorption stage, the direction of liquid flow is changed every 8 cycles.

When the bath ratio is reduced from 1:12 to 1:6, the uniformity of the migration stage can be changed, although the unevenness of the initial dyeing is obvious. In the process of blending dyeing, it is not enough to choose only dyes with similar diffusion properties.

In this case, mixing is more important than mixing. If the amount of the three dyes used for color matching is the same, it is correct to use the dyes with the same diffusion property. However, if the proportion of two dyes is large, and the diffusivity of the third dye should be lower, otherwise it will absorb more quickly than the other two dyes, which is easy to cause uneven dyeing.

2. Recrystallization fine

Disperse dyes are often heated and cooled repeatedly, and the recrystallized particles are larger than 1nm. The recrystallization can be minimized by adding additional dispersants.

In dyeing, when the bath is cooled from 130 ℃ to 90 ℃, some dyes are easy to recrystallize, resulting in poor fastness to rubbing and even clogging the filter in the high-temperature high-pressure dyeing machine.

preventive measure

1. Keep 100 ℃ for a long time, the dye is easy to agglomerate, and the heating rate is adjusted from 100 ℃ to 130 ℃

2. If the dye recrystallizes in the dye bath after reaching the dyeing balance, more dispersants must be added;

3. Some red disperse dyes, such as C.I. disperse red 53, 60, 92, 121, 132, 159, are prone to recrystallization even when their concentration is much lower than the saturation level at the end of dyeing, especially in darker colors.

Especially in hard water dyeing, it is easy to chelate with metal ions.

The resulting chelates have poor solubility under dyeing conditions, leaving blue spots or streaks on the fabric.

There are also factors that cause recrystallization

Auxiliaries, winding oil and alkaline residue added during spinning.

These problems can be avoided by refining before dyeing or adding chelating agent in dyeing bath.

Once the stain occurs, it can be eliminated by alkaline reduction cleaning or acid treatment.

3. Agglomeration and fine focus

Contributing factors

It weakens the dissolving effect of dispersant, reduces the electrostatic mutual exclusion, increases the collision rate of dye particles and improves their kinetic energy.

Generally, the higher the dyeing concentration and temperature, the longer the dyeing time, the greater the possibility of agglomeration and focus. Carriers and levelling agents are easy to replace dispersants which are mixed in dyes, so as to reduce dispersion stability.

Measures to improve dyeing stability

① Disperse the dye at 40 ℃, and use concentrated dispersion;

② The temperature control is the best when the dye solution is heated;

③ The dispersant with protective colloidal effect is used;

④ It is not necessary to use additives with cloud point at high temperature;

⑤ Wash off all dyes and yarn auxiliaries including emulsifiers before dyeing;

⑥ In high temperature dyeing, before most dyes have been dyed on the fabric, carrier and non-ionic levelling agent shall not be added;

⑦ No salt is used, only acetic acid is used to adjust pH value;

⑧ Yarn or dyed fabric should be properly shaped, and laboratory tests should be done to ensure the dispersion stability of disperse dyes.