Do you really know the reason why the sulfur dye soap was washed?

The characteristics of sulfurized dyes

1. Sulfur dye is insoluble in water. When dyeing is dyed, it needs to be restored to the alkali to generate hidden colors and dissolved. The sulfur dye hidden color cellulose fiber is affinity. After dyeing, after oxidation, the insoluble dye is fixed on the fabric.

Yellow is generally 3-4.

3. Incarcitious chromatography, the color is not bright enough, most sulfur dyes are not resistant to chlorine drift, and some varieties have crispy storage. Among them, the storage brittleness of sulfurian melanin is more serious.

The reason why soap washing is good

The soap is good because sulfide dye has changed from soluble hidden color to insoluble dyes after dyeing. Even if the surface of the fabric has a lot of floating colors, it is not easy to dissolve in the solution. The adsorption is absorbed on the fiber.

The difference in friction is because of the following points:

1 Sulfid dye is not easy to dye:

Sulfur dyes are usually high in dyeing and are not easy to penetrate inside the fiber, resulting in a large amount of accumulation on the surface of the fabric. The weak binding force with the fabric fiber was transferred to the cotton stickers when rubbing, and the sample was discolored.

When the dyeing fabric is performed in a wet friction experiment, the covalent key composed of dyes and fibers does not cause floating color due to breaks. It is a dye that generates adsorption by Fan Dehuali. This kind of dye is easy to fall off in the future use process or test.

2 fluoride, C6 waterproofing agent

Some dyed fibers were broken and broken during the friction test, and they became very small colored fiber fine particles, and were eventually transferred to the friction cotton cloth, causing the cotton cloth.

In addition, studies have found that cotton fibers that have not been treated under special treatment will also swell under wet conditions, resulting in a large friction and decreased fiber break. , Fragmentation, falling off and color migration created favorable conditions.

3 Deep dye and improvement of dye itself:

In addition, the deep dye characteristics and improvement of the dye also have a certain impact on friction fastness, because the solidification rate of some dyes will turn lower with the depth of dyeing and the increase of dye concentration. If the dye is improved, the dye -dyeing color solid rate will be higher. In the end, the amount of dye that is not tight is small and easy to wash, so the friction is good; When the dye is dark, the amount of dyes will be a lot without the amount of dyes.

4 Water quality impact:

During our daily dyeing process, water quality is also an important influencing factor. If people use harder water to perform pupils, they will find that because they contain OH-, CO32- and other pussy, they will be with MG2 +, CA2 as MG2 +, CA2 +Inadequate substances such as MGCO3 and CA2CO3 occur in chemical reactions.

These insoluble substances and dyes will eventually be combined, forming color campaigns to deposit to the surface of fabrics. At this time, the friction force produced during friction will greatly increase, resulting in a decrease in wet -resistant friction. In addition, magnesium ions and calcium ions can also produce a chemical reaction with some anion on the dye molecules, thereby transforming into an insoluble substance, which reduces the hydrophilic properties of the dyes, making it difficult for dyes to dissolve and perform in water. Swallowing, the floating color is not easily washed off during washing.

5 Fiber itself influence effect:

In daily wet friction testing, it is found that some cases are completely different from cellulose fiber. Because some fiber's water -expansion effect is not obvious enough or the hygroscopic performance is too low, the existence of water at this time is equivalent to the role of lubricants. The color fastness, which is generally considered to be obviously contrasting with the concept of the dry friction color of textile products that is generally considered to be more than the concept of damp -resistant friction, and often cause people's doubts.

When we analyze this, it is best to consider the fiber characteristics and fabric organizations.

Therefore, people can properly processes fiber or fabric before dyeing. According to different product styles, we can perform the smooth treatment of hair, silk, and fibrin enzymes, as well as drift, washing, cooking, and drying. These can well improve the hair effect and smoothness of the surface of the fabric, reduce friction resistance and floating color, which can effectively improve the wet friction color of the fabric.

Sulfide dye classification

Sulfur dyes can be divided into the following types according to chromatography:

1. Sulfide Yuan (sulfide)

Sunshine fastness can reach level 6-7, soap washing is 4, but it is easy to be brittle. You can add HCHO or sodium chloride to stabilize the sulfur in the dye and not be free to prevent brittle loss.

2. vulcanization blue

The sun exposure can reach level 5-6, and the soap washing fastness is 3-4, such as vulcanized blue brn.

3, yellow, orange, brown

The molecular structure contains aceazole structure, which is low tolerance, and the accuracy of each item is not as good as sulfide and blue.

The nature of vulcanized dyes:

1. Similar to direct dyes

(1) Using salt to promote dyeing

(2) Cattea solid color agent and metal salt color solid agent to improve color fastness

2. Similar to reducing dyes

(1) The dye needs to be reduced into a hidden body before the dyeing fiber can be performed, and oxidation is performed on the fiber. It is just a strong reducing agent insurance powder, but a weak sodium sulfate. However, the direct properties of the hidden color to the fiber after restoration are lower than that of the original dye, and the tendency of dye aggregation is greater.

(2) Activity with acid can generate H2S gas, and the effect of aluminum acetate, which can produce black aluminum sulfide precipitation (used to verify the existence of sulfide dyes)