阅读说明：本技术 一种还原染色还原液配制工艺及还原液、应用 (Preparation process of reduction dyeing reducing solution, reducing solution and application ) 是由 石岷山 魏田裕 龚建 于 2020-12-08 设计创作，主要内容包括：本发明公开了一种还原染色还原液配制工艺及还原液、应用,所述配制工艺包括以下步骤：S1、在配制罐中配制碱液,将碱液的温度控制在≤15℃；S2、将步骤S1配制的碱液放入溶解池,加入保险粉,搅拌溶解获得还原液；S3、将步骤S2获得的还原液泵入储存罐中,还原液储存过程中维持温度≤20℃。本发明通过冷却手段将碱液的热量带走,使碱液温度降低至15℃以下,保险粉加入淡碱液以后,温度会少量上升,但均不会超过20℃,20℃的还原液在存放过程中,其保险粉的分解量将低于每小时1％。明显降低了保险粉用量,节约了成本；本发明在制备还原液的过程中降低了保险粉的消耗量,对提高染色品质,减少色差,都有重要的意义。(The invention discloses a preparation process of reduction dyeing reducing liquid, the reducing liquid and application, wherein the preparation process comprises the following steps: s1, preparing an alkali liquor in a preparation tank, and controlling the temperature of the alkali liquor to be less than or equal to 15 ℃; s2, putting the alkali liquor prepared in the step S1 into a dissolving tank, adding sodium hydrosulfite, stirring and dissolving to obtain reducing liquid; s3, pumping the reducing solution obtained in the step S2 into a storage tank, and maintaining the temperature to be less than or equal to 20 ℃ in the storage process of the reducing solution. The invention takes away the heat of the alkali liquor by a cooling means, so that the temperature of the alkali liquor is reduced to below 15 ℃, the temperature of the sodium hydrosulfite is slightly increased after the sodium hydrosulfite is added into the light alkali liquor, but the temperature of the sodium hydrosulfite does not exceed 20 ℃, and the decomposition amount of the sodium hydrosulfite is lower than 1% per hour in the process of storing the reducing liquid at 20 ℃. The using amount of the sodium hydrosulfite is obviously reduced, and the cost is saved; the method reduces the consumption of the sodium hydrosulfite in the process of preparing the reducing solution, and has important significance for improving the dyeing quality and reducing the color difference.)

1. A preparation process of reduction dyeing reducing liquid is characterized by comprising the following steps:

s1, preparing an alkali liquor in a preparation tank, and controlling the temperature of the alkali liquor to be less than or equal to 15 ℃;

s2, putting the alkali liquor prepared in the step S1 into a dissolving tank, adding sodium hydrosulfite, stirring and dissolving to obtain reducing liquid;

s3, pumping the reducing solution obtained in the step S2 into a storage tank, and maintaining the temperature to be less than or equal to 20 ℃ in the storage process of the reducing solution.

2. The process for preparing reduction dyeing reducing solution according to claim 1, wherein the concentrations of alkali and sodium hydrosulfite in the reducing solution are 75g/l and 80g/l respectively.

3. The process of claim 1, wherein the preparation tank is provided with a heat exchange device, and the temperature of the alkali liquor is controlled to be less than or equal to 15 ℃ by circularly introducing cooling water of 10 ℃ +/-2 ℃ through the heat exchange device.

4. The process according to claim 1, wherein a predetermined amount of sodium hydrosulfite is added into 15 ℃ alkaline solution, and the temperature of the reducing solution is controlled to be less than or equal to 20 ℃.

5. The process of claim 1, wherein the lye in step S1 is prepared by the following steps:

adding high-concentration alkali liquor with the concentration of 100g/l into a preparation tank, and then adding tap water to dilute to obtain the alkali liquor.

6. The process of claim 1, wherein in step S2, the sodium hydrosulfite is 85% sodium hydrosulfite.

7. The process according to any one of claims 1 to 6, wherein the alkaline solution in step S1 is made of caustic soda.

8. A reducing solution prepared by the reducing dyeing reducing solution preparation process according to any one of claims 1 to 7.

9. The reducing solution prepared by the reduction dyeing reducing solution preparation process according to claim 8, wherein the temperature of the stock solution is less than or equal to 20 ℃, and the concentrations of alkali and sodium hydrosulfite in the reducing solution are 75g/l and 80g/l respectively.

10. The use of the reducing solution prepared by the reducing dyeing reducing solution preparation process according to claim 8, wherein the reducing solution is diluted with water to a working concentration by an automatic solution preparation system during use.

Technical Field

The invention relates to the technical field of printing and dyeing processing, in particular to a preparation process of a reduction dyeing reducing liquid, the reducing liquid and application.

Background

The vat dyes have excellent color fastness and have an important position in the field of cellulose fiber dyeing. The production of the frock fabric adopts vat dyes with excellent fastness as far as possible, so that the vat dyes have larger specific gravity. In the process of the reduction dyeing process, a dye needs to be reduced and dissolved into leuco sodium salt, the used reducing agent is sodium hydrosulfite, and the sodium hydrosulfite is also used in other printing and dyeing processes to different degrees, for example, the sodium hydrosulfite is required to be used in the reduction cleaning process for improving the color fastness of polyester cotton, the stripping process for treating the problem of dyeing quality and the like. The cost of the sodium hydrosulfite in the printing and dyeing auxiliary agent is very high, and the sodium hydrosulfite is the auxiliary agent with the largest expenditure.

Sodium hydrosulfite (sodium dithionite) Na₂O₄S₂The sodium hydrosulfite is unstable and easy to decompose when heated and wetted, and statistically 10-15% of sodium hydrosulfite is dissipated in the using process, so that the waste is remarkable, and the instability of the sodium hydrosulfite concentration can directly cause the color difference before and after dyeing of the product, thereby causing quality problems.

Therefore, the consumption of the sodium hydrosulfite is reduced, especially the non-process waste in the using process of the sodium hydrosulfite is reduced, the economic value is high, and the dyeing method has important significance for improving the dyeing quality and reducing the color difference.

Disclosure of Invention

The invention aims to provide a preparation process of reduction dyeing reducing solution, which aims to reduce the consumption of sodium hydrosulfite in the preparation process of the reducing solution, improve the dyeing quality of the reducing solution and reduce color difference.

In addition, the invention also provides the reducing liquid prepared by the preparation process and application of the reducing liquid.

The invention is realized by the following technical scheme:

a preparation process of reduction dyeing reducing liquid comprises the following steps:

s1, preparing an alkali liquor in a preparation tank, and controlling the temperature of the alkali liquor to be less than or equal to 15 ℃;

s2, putting the alkali liquor prepared in the step S1 into a dissolving tank, adding sodium hydrosulfite, stirring and dissolving to obtain reducing liquid;

s3, pumping the reducing solution obtained in the step S2 into a storage tank, and maintaining the temperature to be less than or equal to 20 ℃ in the storage process of the reducing solution.

The sodium hydrosulfite in the sodium hydrosulfite/caustic soda solution is easy to decompose and lose, the temperature is about 40 ℃ in the existing preparation process, and the applicant discovers through long-term tests that:

the decomposition rate of sodium hydrosulfite in the sodium hydrosulfite/caustic soda solution is 20%/h at 40 ℃, and 10%/h at 30 ℃; the decomposition is reduced to below 1%/h at 20 ℃. The higher the temperature, the higher the decomposition rate. The preparation of the sodium hydrosulfite/caustic soda solution is an exothermic process, which can cause the temperature of the sodium hydrosulfite/caustic soda solution to rise, and the decomposition loss of the sodium hydrosulfite can be aggravated.

The temperature of the alkali liquor is reduced to below 15 ℃, then the sodium hydrosulfite is added, so that the temperature of the caustic soda/sodium hydrosulfite solution is reduced to below 20 ℃, then the caustic soda/sodium hydrosulfite solution is pumped into a storage tank with a temperature layer for standby, the temperature is maintained to be less than or equal to 20 ℃ in the storage process of the reducing solution, the low-temperature caustic soda/sodium hydrosulfite solution can be stored for 3 hours, the concentration is reduced little, and the requirements of the dyeing process are completely met.

In conclusion, the invention takes away the heat of the alkali liquor by a cooling means, so that the temperature of the alkali liquor is reduced to below 15 ℃ (the temperature is generally above 40 ℃ in the prior art), the temperature of the sodium hydrosulfite is slightly increased after the sodium hydrosulfite is added into the light alkali liquor, but the temperature of the sodium hydrosulfite cannot exceed 20 ℃, and the decomposition amount of the sodium hydrosulfite is lower than 1% per hour in the storage process of the reducing liquid at 20 ℃. The using amount of the sodium hydrosulfite is obviously reduced, and the cost is saved.

The invention reduces the consumption of the sodium hydrosulfite in the process of preparing the reducing solution, so that the prepared reducing solution can improve the dyeing quality and reduce the color difference in the reduction dyeing process.

Further, the concentrations of the alkali and the sodium hydrosulfite in the reducing solution are 75g/l and 80g/l respectively.

Furthermore, the preparation tank is provided with a heat exchange device, and cooling water with the temperature of 10 +/-2 ℃ is circularly introduced through the heat exchange device to control the temperature of the alkali liquor to be less than or equal to 15 ℃.

The cooling water is tap water with the temperature of 10 +/-2 ℃, and is obtained by cooling through a compression refrigerator, and the whole process flow is as follows: the refrigerating machine cools the alkali liquor to 15-15 deg.C-alkali liquor and sodium hydrosulfite to form 20-20 deg.C reducing liquor, which is stored in the liquid storage tank for later use. The liquid storage tank does not need to be cooled by an interlayer, and the heat preservation treatment is carried out.

Further, adding a specified amount of sodium hydrosulfite into 15 ℃ alkali liquor, and finally controlling the temperature of the reducing liquid to be less than or equal to 20 ℃.

Further, the process of preparing the lye in step S1 is as follows:

adding high-concentration alkali liquor with the concentration of 100g/l into a preparation tank, and then adding tap water to dilute to obtain the alkali liquor.

In the process, the liquid concentrated alkali system alkali recovery system is obtained by high-temperature concentration, and has a certain temperature which is more than 45 ℃; in the process of diluting high concentration to low concentration, a certain amount of heat is released to continuously raise the temperature of the liquid; in the process of dissolving the sodium hydrosulfite in the caustic soda solution, the heat of dissolution is also released, so that the temperature is further increased to be higher than 50 ℃, therefore, the temperature of the alkali liquor is reduced and controlled to be lower than 15 ℃ by a cooling means, the temperature of the sodium hydrosulfite/caustic soda (reducing liquid) is not higher than 20 ℃, and the loss of the sodium hydrosulfite can be reduced.

Further, in step S2, the sodium hydrosulfite is sodium hydrosulfite with an effective content of 85%.

Further, in step S1, the alkali solution is made of caustic soda.

The reducing liquid is prepared by adopting a reducing dyeing reducing liquid preparation process.

Further, the temperature of the stock solution is less than or equal to 20 ℃, and the concentrations of the alkali and the sodium hydrosulfite in the reducing solution are 75g/l and 80g/l respectively.

The application of reducing liquid prepared by a reducing dyeing reducing liquid preparation process is to dilute the reducing liquid into working concentration by using water through an automatic liquid preparation system when in use.

The automatic liquid preparation system has the advantages of rapidness and accuracy.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention takes away the heat of the alkali liquor by a cooling means, so that the temperature of the alkali liquor is reduced to below 15 ℃, the temperature of the sodium hydrosulfite is slightly increased after the sodium hydrosulfite is added into the light alkali liquor, but the temperature of the sodium hydrosulfite does not exceed 20 ℃, and the decomposition amount of the sodium hydrosulfite is lower than 1% per hour in the process of storing the reducing liquid at 20 ℃. The using amount of the sodium hydrosulfite is obviously reduced, and the cost is saved.

2. The method reduces the consumption of the sodium hydrosulfite in the process of preparing the reducing solution, and has important significance for improving the dyeing quality and reducing the color difference.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not used as limitations of the present invention.

Example 1:

a preparation process of reduction dyeing reducing liquid comprises the following steps:

s1, preparing alkali liquor in a preparation tank, and controlling the temperature of the alkali liquor at 15 ℃:

1550 liters of liquid caustic soda with high concentration and 100g/l is added into a preparation tank with 2-square capacity and a heat preservation function, the caustic soda is made of caustic soda, and then 400l of tap water is added to synthesize 77.5g/l of light alkali solution (the caustic soda solution);

the heat preservation function specifically means that the preparation tank is provided with a heat exchange device, cooling water with the temperature of 10 +/-2 ℃ is circularly led in through the heat exchange device, the temperature of the alkali liquor is controlled to be 15 ℃, and tap water with the temperature of 10 +/-2 ℃ is obtained by a refrigeration compressor unit through a heat exchanger.

S2, putting 1950 liters of alkali liquor prepared in the step S1 into a dissolving tank, then slowly putting 200kg of sodium hydrosulfite with the effective content of 85 percent into 8 barrels one by one, starting to slowly stir until the sodium hydrosulfite is completely dissolved, finally, adjusting the volume of the reducing solution to be 2050 liters by using a small amount of tap water, and closing a stirrer to obtain the reducing solution;

and S3, pumping the 2050 liters of low-temperature reducing solution prepared in the step S2 into a storage tank with the volume of 3 square volumes for later use, maintaining the temperature at 19.8 ℃ in the storage process of the reducing solution, and diluting the reducing solution into working concentration by using water through an automatic solution preparation system when in use.

In the embodiment, the concentrations of caustic soda and sodium hydrosulfite in the reducing solution are about 75g/l and 80g/l respectively.

Example 2:

this example is based on example 1, and differs from example 1 in that:

in step S1, the temperature of the alkali liquor is controlled at 12 ℃, and the temperature of the reducing solution is 17 ℃ when the reducing solution is stored.

Comparative example 1:

this comparative example is based on example 1 and differs from example 1 in that:

in step S1, the temperature of the alkali liquor is controlled at 20 ℃, and the temperature of the reducing solution is 25.5 ℃ when the reducing solution is stored.

Comparative example 2:

this comparative example is based on example 1 and differs from example 1 in that:

in step S1, the temperature of the alkali liquor is controlled at 25 ℃, and the temperature of the reducing solution is 31.1 ℃ when the reducing solution is stored.

Comparative example 3:

this comparative example is based on example 1 and differs from example 1 in that:

in step S1, the temperature of the alkali liquor is controlled at 30 ℃, and the temperature of the reducing solution is 36.5 ℃ when the reducing solution is stored.

The reduction solutions prepared in examples 1 to 2 and comparative examples 1 to 5 were respectively tested for sodium hydrosulfite decomposition rate (/ hour), and the results are shown in table 1:

TABLE 1

From the data in table 1, it can be seen that:

when the temperature of the alkali liquor is controlled below 15 ℃, the temperature of the reducing liquid is lower than 20 ℃, the decomposition rate of the sodium hydrosulfite in the reducing liquid is less than or equal to 1% per hour, the temperature of the reducing liquid rises along with the temperature of the alkali liquor, the decomposition rate of the sodium hydrosulfite in the reducing liquid also rises along with the temperature rise, and the rising proportion rises along with the temperature rise.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.