Novel denim processing technology

Abstract

The invention relates to the technical field of denim processing, in particular to a novel denim processing technology. Comprising the following steps: pretreatment: putting denim into a solution of a scouring agent and caustic soda, and treating at 95 DEG C for 30-60 minutes to obtain treated denim; the method comprises the following steps: gradually adding a modifier, a penetrating agent and yarns into a 50-80 DEG C aqueous solution by adopting a cationic modifier, dipping in an electric heating constant-temperature water bath kettle, taking out, washing with water, and removing excessive water by using a padder to obtain modified denim; a full-bath reduction method is adopted, indigo dye, sodium hydroxide and sodium hydrosulfite are sequentially added into a beaker at the temperature of 60 DEG C, heat preservation and reduction are conducted, clear and transparent yellow-green indigo reduction dye liquor is obtained, standing and cooling are conducted to room temperature for dyeing, and dyed denim is obtained; and fixation: performing padding treatment on the denim fabric in a 40-80g / L color fixing agent, and performing drying and baking treatment to obtain the novel denim fabric.

Description

Technical Field

[0001] The invention relates to the technical field of denim processing, and more particularly to a novel denim processing technology. Background Art

[0002] As a classic clothing fabric, denim is deeply loved by consumers for its toughness, durability and unique style. However, with the development of the times and the improvement of people's requirements for the performance of clothing fabrics, traditional denim fabrics can no longer meet all needs. Therefore, developing a new type of denim composite fabric to improve the performance, aesthetics and comfort of the fabric has become an important research direction in the current textile industry. In the existing technology, denim is usually processed by sanding, flocking, embroidery and coating, as well as various chemical treatment methods, including grinding, fossil washing, sand washing, rinsing and other processing processes to obtain different denim appearances. During the secondary processing, the chemicals remaining on the denim may also harm the wearer.

[0003] A Chinese patent discloses a manufacturing method of a denim composite fabric and a denim composite fabric (publication number CN109130345A). The patented technology uses a needle punching process to hook the fibers on the lower surface of the denim layer to the upper surface of the denim to form a jacquard layer. The jacquard layer can form various three-dimensional patterns, so that the unique appearance style of the denim is formed by a physical method without the need for secondary dyeing, chemical treatment and other processes, saving resources and reducing environmental pollution; after jacquard, the lower surface of the denim layer is hot-ironed and shaped; the base fabric layer and the denim layer are fixed by a hot pressing process, so that the produced denim composite fabric is smoother, stronger and more durable, has a unique appearance style, a three-dimensional and full pattern, a soft feel, and is comfortable to wear.

[0004] In the modern textile printing and dyeing process, especially in the process of dyeing denim, indigo dye is the most widely used vat dye. Indigo is blue or dark blue, odorless, and uniform powder. Modern light sources place indigo in the electromagnetic spectrum between 420 and 450nm, which is on the short-wave side of the blue color wheel, toward the (spectral) purple. Indigo is slightly soluble in water, ethanol, and glycerin, but insoluble in oils and fats. It is dark blue when exposed to concentrated sulfuric acid, and its aqueous solution is green to yellow-green when added with sodium hydroxide. Indigo is easy to color and has a unique hue. It is widely used, but its heat resistance, alkali resistance, oxidation resistance, and bacterial resistance are all poor. Summary of the invention

[0005] The invention provides a novel denim processing technology. The whole process reduces the sewage treatment pressure and the environmental pressure, making the denim dyeing process cleaner and greener.

[0006] In a first aspect, the present invention provides a novel denim processing process, comprising the following steps:

[0007] (4) Pretreatment: The denim is placed in a solution of a scouring agent and caustic soda at 95°C for 30 to 60 minutes to obtain treated denim;

[0008] (5) using a cationic modifier to treat the denim, gradually adding the modifier, penetrant, and yarn into a 50-80° C. aqueous solution, immersing the denim in an electric constant temperature water bath, taking it out and washing it with water, and using a rolling mill to remove excess water to obtain a modified denim;

[0009] (6) Dyeing: Using the full-bath reduction method, indigo dye, sodium hydroxide, and hydrosulfite are added to a beaker in sequence at 60° C., and the mixture is reduced by heat preservation to obtain a clear and transparent yellow-green indigo reduction dye solution, which is then allowed to stand and cool to room temperature for dyeing to obtain a dyed denim fabric;

[0010] (7) Color fixing: The dyed denim is immersed in 40-80 g / L of a color fixing agent, and then dried and baked to obtain a new type of denim.

[0011] Preferably, in step (1), the concentration of the refining agent is 5-10 g / L.

[0012] Preferably, in step (2), the modifier is one or more of 3-chloro-2-hydroxypropyltrimethylammonium chloride, 1-chloro-2-hydroxypropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, amino-terminated hyperbranched compounds, polyepichlorohydrin dimethylamine, and styrene-b-isoprene-b-styrene.

[0013] Preferably, in step (2), the penetrant is one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, sodium alkylbenzene sulfonate, and sodium alkyl sulfate.

[0014] Preferably, in step (2), the concentration of the modifier is 50-110 g / L.

[0015] Preferably, in step (3), the amount of sodium hydroxide used is 3-6 g / L.

[0016] Preferably, in step (3), the indigo dye is prepared by modification treatment of hydrated ferric sulfate, calcium gluconate and triethanolamine, and the mass ratio of hydrated ferric sulfate, calcium gluconate and triethanolamine is 1:(0.5-2):(1.2-3).

[0017] Preferably, in step (4), the drying temperature is 110-120° C. and the drying time is 5-15 min.

[0018] In summary, the present invention has the following beneficial effects:

[0019] 1. The present invention improves the wet rubbing fastness of denim by strengthening the pre-treatment process, regulating the state of indigo leuco, enhancing the permeability of indigo dye, optimizing the color fixing process;

[0020] 2. The present invention regulates the indigo leuco body to be in the state of bisphenol sodium salt, which increases the dye penetration to a certain extent, thereby improving the wet friction fastness of the indigo denim;

[0021] 3. In order to improve the dyeing rate of reactive dyes on denim, the present invention often uses a cationic modifier to allow cotton fibers to obtain cationic groups, thereby improving the affinity of denim for the dye.

[0022] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit the scope of protection of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0024] Example

[0025] Example 1

[0026] A novel denim processing technology comprises the following steps:

[0027] (1) Pretreatment: The denim was placed in a solution of scouring agent and caustic soda at 95°C for 60 min to obtain treated denim; the concentration of the scouring agent was 10 g / L.

[0028] (2) The denim treated with a cationic modifier is gradually added with the modifier, penetrant, and yarn into an aqueous solution at 80°C, immersed in an electric constant temperature water bath, taken out and washed with water, and excess water is removed by a rolling mill to obtain a modified denim; the modifier is a mixture of 3-chloro-2-hydroxypropyltrimethylammonium chloride and polyepichlorohydrin dimethylamine in a mass ratio of 1:2; the concentration of the modifier is 80 g / L; the penetrant is fatty alcohol polyoxyethylene ether.

[0029] (3) Dyeing: Using the full-bath reduction method, indigo dye, sodium hydroxide, and hydrosulfite are added to a beaker in sequence at 60°C, and the mixture is reduced at this temperature to obtain a clear and transparent yellow-green indigo reduction dye solution, which is then allowed to stand and cool to room temperature for dyeing to obtain dyed denim. The amount of sodium hydroxide used is 6 g / L. The indigo dye is prepared by modification treatment with hydrated ferrous sulfate, calcium gluconate, and triethanolamine, and the mass ratio of hydrated ferrous sulfate, calcium gluconate, and triethanolamine is 1:2:3.

[0030] (4) Color fixation: The dyed denim was immersed in 80 g / L of a color fixative, and then dried and baked at a temperature of 120° C. for 15 min to obtain a new type of denim.

[0031] Example 2

[0032] A novel denim processing technology comprises the following steps:

[0033] (1) Pretreatment: The denim was placed in a solution of a scouring agent and caustic soda at 95°C for 400 min to obtain treated denim; the concentration of the scouring agent was 10 g / L.

[0034] (2) The denim treated with a cationic modifier is gradually added with the modifier, penetrant, and yarn in an aqueous solution at 80°C, immersed in an electric constant temperature water bath, taken out and washed with water, and excess water is removed by a rolling mill to obtain a modified denim; the modifier is a mixture of 3-chloro-2-hydroxypropyltrimethylammonium chloride and an amino-terminated hyperbranched compound in a mass ratio of 1:1; the penetrant is an alkylphenol polyoxyethylene ether; and the concentration of the modifier is 50 g / L.

[0035] (3) Dyeing: Using the full-bath reduction method, indigo dye, sodium hydroxide, and hydrosulfite are added to a beaker in sequence at 60°C, and the mixture is reduced at this temperature to obtain a clear and transparent yellow-green indigo reduction dye solution, which is then allowed to stand and cool to room temperature for dyeing to obtain dyed denim. The amount of sodium hydroxide used is 3-6 g / L. The indigo dye is prepared by modification treatment with hydrated ferrous sulfate, calcium gluconate, and triethanolamine, and the mass ratio of hydrated ferrous sulfate, calcium gluconate, and triethanolamine is 1:1:2.

[0036] (4) Color fixation: The dyed denim was immersed in 80 g / L of a color fixative, and then dried and baked at a temperature of 120° C. for 8 min to obtain a new type of denim.

[0037] Example 3

[0038] A novel denim processing technology comprises the following steps:

[0039] (1) Pretreatment: The denim was placed in a solution of scouring agent and caustic soda at 95°C for 60 min to obtain treated denim; the concentration of the scouring agent was 10 g / L.

[0040] (2) The denim treated with a cationic modifier is gradually added with the modifier, penetrant, and yarn in an 80°C aqueous solution, immersed in an electric constant temperature water bath, taken out and washed with water, and excess water is removed by a rolling mill to obtain a modified denim; the modifier is a mixture of 1-chloro-2-hydroxypropyltrimethylammonium chloride and polyepichlorohydrin dimethylamine in a mass ratio of 1:1; the penetrant is fatty alcohol polyoxyethylene ether; and the concentration of the modifier is 100 g / L.

[0041] (3) Dyeing: Using the full-bath reduction method, indigo dye, sodium hydroxide, and hydrosulfite are added to a beaker in sequence at 60°C, and the mixture is reduced at this temperature to obtain a clear and transparent yellow-green indigo reduction dye solution, which is then allowed to stand and cool to room temperature for dyeing to obtain dyed denim. The amount of sodium hydroxide used is 5 g / L. The indigo dye is prepared by modification treatment with hydrated ferrous sulfate, calcium gluconate, and triethanolamine, and the mass ratio of hydrated ferrous sulfate, calcium gluconate, and triethanolamine is 1:2:3.

[0042] (4) Color fixation: The dyed denim was immersed in 80 g / L of a color fixative, and then dried and baked at a temperature of 110° C. for 5 min to obtain a new type of denim.

[0043] Comparative Example 1

[0044] The difference from Example 1 is that step (1) is not performed, and the rest is the same as Example 1.

[0045] Comparative Example 2

[0046] The difference from Example 1 is that no modifier is added in step (2), and the rest is the same as Example 1.

[0047] Comparative Example 3

[0048] The difference from Example 1 is that the modifier is replaced by chitosan, and the rest is the same as Example 1.

[0049] Comparative Example 4

[0050] The difference from Example 1 is that the indigo dye is not modified in step (3), and the rest is the same as Example 1.

[0051] The SF600PLUS colorimeter was used for measurement. The indigo-dyed fabric was folded into 4 layers (opaque), and the color was measured under the conditions of D65 light source and 10° angle. Four different positions of each fabric were tested, and the average value was taken as the required data.

[0052] The rubbing fastness of fabrics is rated according to GB / T3920-2008 “Textiles - Tests for Colour Fastness - Colour Fastness to Rubbing” and the standard grey scale is used for comparison.

[0053] The dyeing K / S value and wet rubbing fastness are shown in the following table:

[0054] Table 1 K / S value and wet rubbing fastness of dyeing in Examples 1-3 and Comparative Examples 1-4

[0055]

[0056] It can be seen from the above table that the K / S values ​​of Experimental Examples 1-3 are all around 11.80, which are all greater than Comparative Example 1; the friction fastness levels of Experimental Examples 1-3 are 3-4, which are all greater than Comparative Example 1.

[0057] From this, it can be analyzed that: compared with the prior art, the denim produced by the present invention increases the indigo dyeability and improves the wet friction fastness of the indigo denim from level 2-3 to level 4.

[0058] The above is only an exemplary embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A new denim processing technology, characterized in that: The following steps are involved: (1) Pretreatment: The denim is placed in a solution of a scouring agent and caustic soda at 95°C for 30 to 60 minutes to obtain treated denim; (2) using a cationic modifier to treat the denim, gradually adding the modifier, penetrant, and yarn into a 50-80° C. aqueous solution, immersing in an electric constant temperature water bath, taking out and washing, and using a rolling mill to remove excess water to obtain a modified denim; (3) Dyeing: Using the full-bath reduction method, indigo dye, sodium hydroxide, and hydrosulfite are added to a beaker in sequence at 60°C, and the mixture is reduced by heat preservation to obtain a clear and transparent yellow-green indigo reduction dye solution, which is then allowed to stand and cool to room temperature for dyeing to obtain the dyed denim; (4) Color fixation: The dyed denim is immersed in 40-80 g / L of a color fixative, and then dried and baked to obtain a new type of denim.

2. The novel denim processing technology according to claim 1 is characterized in that: In step (1), the concentration of the refining agent is 5-10 g / L.

3. The novel denim processing technology according to claim 1 is characterized in that: In step (2), the modifier is one or more of 3-chloro-2-hydroxypropyltrimethylammonium chloride, 1-chloro-2-hydroxypropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, amino-terminated hyperbranched compounds, polyepichlorohydrin dimethylamine, and styrene-b-isoprene-b-styrene.

4. The novel denim processing technology according to claim 1 is characterized in that: In step (2), the penetrant is one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, sodium alkylbenzene sulfonate, and sodium alkyl sulfate.

5. The novel denim processing technology according to claim 1 is characterized in that: In step (2), the concentration of the modifier is 50-110 g / L.

6. The novel denim processing technology according to claim 1 is characterized in that: In step (3), the dosage of sodium hydroxide is 3-6 g / L.

7. The novel denim processing technology according to claim 1 is characterized in that: In step (3), the indigo dye is prepared by modification treatment of hydrated ferric sulfate, calcium gluconate and triethanolamine, and the mass ratio of hydrated ferric sulfate, calcium gluconate and triethanolamine is 1:(0.5-2):(1.2-3).

8. The novel denim processing technology according to claim 1 is characterized in that: In step (4), the drying temperature is 110-120° C. and the drying time is 5-15 min.

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