Do you know 9 kinds of quality problems caused by too soft treating after dyeing process?

Many dyeing masters may sneer and disagree. In actual operation, many dyeing masters used the wrong method of direct pumping to make more output, which caused uneven soft oil on the cloth surface!

In production, the touch panel is often used, and the color light is normal, but after the finalization, the following 9 situations will appear:

1. Discoloration and yellowing:

The reason is that the yellowing is generally caused by a certain structure of the film and the amino group in the amino silicone oil.

In the film, the cationic film is soft and has a good hand feeling. It is easy to be adsorbed on the fabric, but it is easy to yellow and change color, which affects the hydrophilicity. If the cationic film is modified into soft oil, its yellowing will be greatly reduced, and the hydrophilicity is also Improvement, such as compounding cationic film with hydrophilic silicone oil, or compounding with hydrophilic finishing agent, its hydrophilicity will be improved.

Anionic film or non-ionic film is not easy to yellow, and some films do not yellow, nor affect hydrophilicity.

Amino silicone oil is currently the most widely used silicone oil, but because the amino group will cause discoloration and yellowing, the higher the ammonia value, the greater the yellowing. It should be replaced with low yellowing amino silicone oil or polyether modification, epoxy modification, etc. Yellow silicone oil.

In addition, cationic surfactants such as 1227, 1831, and 1631 are sometimes used as emulsifiers during emulsion polymerization. These emulsifiers can also cause yellowing.

When silicone oil is emulsified, the emulsifier is different, and its "peeling effect" is different, which will cause peeling and light color under different conditions, which is a color change.

2. Can't reach the desired feel:

The soft style of soft finishing varies with different customer requirements, such as soft, smooth, fluffy, soft waxy, oily, dry and slippery, etc. Different softeners are selected according to different styles. For example, in the film, there are softener films with different structures, and their softness, bulkiness, smoothness, yellowing, and influence on the water absorption of the fabric are all different; among the silicone oils, the properties of modified silicone oils with different modified genes are also different. Such as amino silicone oil, hydroxy silicone oil, epoxy modified silicone oil, carboxyl modified silicone oil, etc., all have different properties.

3. Decreased hydrophilicity of fabric:

Generally, problems with the structure of the film used and the lack of water absorption genes after the formation of silicone oil, and the blocking of water absorption centers such as the hydroxyl groups of cellulose fibers, the carboxyl groups and amino groups on wool, etc., cause the water absorption to decrease. Anionic and non-ionic films should be used as much as possible. And hydrophilic type silicone oil.

4. Dark spots:

The main reason is that the oil stain on the fabric is not cleaned during the pretreatment, and the color of the oil stain is too dark during dyeing; or there is too much foam in the dyeing bath, and the mixture of foam, flower sweater, dye, etc. sticks to the fabric; or the defoamer floating oil causes dark color Oil spots; or the tar substance in the dyeing tank sticks to the fabric; or the dye agglomerates to form dark spots under different conditions; or the water quality is too much calcium and magnesium ions combined with the dye to stick to the fabric. It should be treated in a targeted manner, such as adding a degreasing agent for scouring during pre-treatment, using low-foaming and non-foaming additives for dyeing auxiliaries, selecting defoaming agents that are not easy to float, adding chelating agents to improve water quality, and adding solubilizing and dispersing agents To prevent dye agglutination, clean the vat with cleaning agent in time.

5. Light spots:

The main reason is that the pretreatment is uneven, and the hair effect of some parts is not good, resulting in a certain degree of repellency, or with repellent substances, or the cloth has calcium soap, magnesium soap, etc. or uneven mercerization during the pretreatment. Or the semi-products are not evenly dried, or the cloth surface is stained with undissolved sodium sulfate, soda ash and other solids, or the dyed product is dripped with water before drying, or the dyed product is softened and treated with additives during finishing. The same must be targeted treatment, such as strengthening the pretreatment, the selection of pretreatment auxiliaries must not be easy to form calcium and magnesium soap, and the pretreatment must be uniform and thorough (this is related to the selection of scouring agent, penetrant, chelating dispersant, mercerizing penetrant, etc. ), sodium sulfate, soda ash, etc. must be put into the tank well and production management must be strengthened.

6. Alkali spots:

The main reason is that the alkali removal after pretreatment (such as bleaching and mercerizing) is not clean or uniform, causing alkali spots, so the alkali removal process of the pretreatment process must be strengthened.

7. Softener stains:

There are probably the following reasons:

a. The soft flake material is not good, and there is a block softener adhering to the fabric;

b. There is too much foam after the soft sheet is formed, and the softener foam stains on the cloth when the cloth comes out of the tank;

c. The water quality is poor, the hardness is too high, and the impurities in the water combine with the softener and agglomerate on the fabric. Some plants even use sodium hexametaphosphate or alum to treat water. These substances form flocs with impurities in the water, which will stain the cloth surface after entering the softening bath;

d. The cloth surface has anionic substances, which can be combined with cationic softeners during soft processing to form stains, or the cloth surface has alkalis to make the softeners agglomerate;

e. The structure of the softener is different, and some of the softener changes from an emulsified state to a scum stick to the fabric at a higher temperature.

f. The original tar-like softener and other substances in the tank fall off and stick to the fabric.

8. Silicone oil stains:

This is the most difficult type of stain, the main reasons are:

a. The pH value of the cloth surface is not neutral, especially with alkali, causing silicone oil to break and float;

b. The water quality of the treatment bath is too poor, the hardness is too high, and the silicone oil is very easy to float in the water with hardness> 150PPM;

c. Silicone oil quality problems include poor emulsification (poor choice of emulsifier, poor emulsification process, too large emulsified particles, etc.), and intolerance to shear (mainly problems with silicone oil itself, such as silicone oil quality, emulsification system, silicone oil variety, silicone oil synthesis process, etc.) ).

You can choose silicone oil that is resistant to shear, electrolyte, and pH changes, but you should pay attention to the way the silicone oil is used and the environment, and you can also consider choosing a hydrophilic silicone oil.

9. Poor fuzzing:

Poor raising is closely related to the operation of the raising machine (such as tension control, raising roller speed, etc.). For raising, when applying softener (commonly known as waxing), controlling the dynamic and static friction coefficient of the fabric is the key, so the raising is soft The preparation of the agent is the key. If the softener is not used well, it will directly cause poor fluffing, and even cause breakage or door width change.