Powder preparation method of dye plant extract, dye powder and textile dyeing method

Abstract

The invention relates to a powder preparation method of a dye plant extract, dye powder and a textile dyeing method. The powdering method comprises the following steps: soaking dye plant raw material powder to extract carbohydrates at 70-90 DEG C under an alkaline condition by using ethanol as a solvent, and separating an ethanol extracting solution after the extraction is completed; taking water as an extraction solvent, and extracting the dye plant raw material subjected to the sugar removal treatment to obtain an extracting solution; concentrating the extracting solution, and adding dextrin; and performing spray drying to prepare dye powder. The invention also provides a dyeing method based on the dye powder. According to the technical scheme provided by the invention, macromolecular saccharides can be converted into micromolecular saccharides under high-temperature and alkaline conditions, and the micromolecular saccharides are dissolved in ethanol to be removed, so that the content of saccharide impurities in pigment dye during subsequent aqueous solution extraction is greatly reduced, and the problem of wall sticking of an extract in a drying tower during spray drying can be obviously improved with the help of dextrin.

Description

Technical Field

[0001] This invention relates to a method for preparing dye plant extracts into powder, dye powder, and a method for dyeing textiles, belonging to the field of textile technology. Background Technology

[0002] In the food processing industry, farmers generate a large amount of plant waste after collecting fruit pulp and fruit, such as pomegranate peels, walnut husks, grape skins, and grape seeds. This plant waste is usually returned to the soil as fertilizer, which has very low added value. According to data, these plant wastes contain rich natural pigments and dyes that can be used for dyeing in the textile industry, greatly increasing their added value. In addition, these dyes are renewable and meet the requirements of sustainable development and environmental protection. At the same time, fabrics dyed with natural dyes exhibit a natural and simple beauty, which is gradually gaining popularity.

[0003] However, these fruit peels or fruit wastes contain a large amount of sugars, which can account for 20-70% of the extract. Due to the strong hygroscopicity, low glass transition temperature and high viscosity of some sugars, the plant extracts are prone to sticking to the walls of the drying tower during spray drying, making it difficult to form powder and collect. They are also very easy to absorb moisture and clump during storage, which seriously affects their subsequent performance.

[0004] Therefore, developing a suitable powdering method for plant extracts with high sugar content is one of the urgent problems to be solved in this field. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention aims to provide a method for preparing dye plant extracts into powder and a method for dyeing textiles, wherein the powder preparation method can prepare dye plant extracts into high-performance dye powder.

[0006] To achieve the above objectives, the present invention provides a method for preparing a powder from a dye plant extract, comprising the following steps:

[0007] Step 1: Grind the dried dye plant materials into powder, sieve, and obtain dye plant material powder;

[0008] Step 2: Using ethanol as a solvent and adjusting the pH to alkaline, the dye plant raw material powder is soaked at 70-90℃ under alkaline conditions to extract sugars. After extraction, the ethanol extract is separated, and the remaining solid is the dye plant raw material that has undergone sugar removal treatment.

[0009] Step 3: Use water as the extraction solvent to extract the dye plant raw material after the sugar removal treatment to obtain the extract;

[0010] Step 4: Concentrate the extract, and after concentration, add dextrin to obtain the concentrated extract;

[0011] Step 5: The concentrated extract is made into dye powder by spray drying.

[0012] According to a specific embodiment of the present invention, preferably, the sieve used for sieving has a mesh size of 60-120 mesh, more preferably 60-100 mesh.

[0013] According to a specific embodiment of the present invention, sugars can be extracted by using ethanol as a solvent, thereby reducing sugar impurities in the final dye powder. The specific extraction process can be carried out by soaking or boiling the plant extracts.

[0014] According to a specific embodiment of the present invention, preferably, the mass fraction of the ethanol is 60%-100%; 100% is anhydrous ethanol.

[0015] According to a specific embodiment of the present invention, preferably, the pH value is 10.0-13.0, more preferably 11.0-13.0, and even more preferably 11.5-12.5.

[0016] According to a specific embodiment of the present invention, preferably, the pH value is adjusted by adding sodium hydroxide.

[0017] According to a specific embodiment of the present invention, preferably, when separating the ethanol extract, the ethanol extract can be pumped into a storage tank, and the ethanol and sugars in the solid residue can be recovered by distillation.

[0018] According to a specific embodiment of the present invention, preferably, in step two, when ethanol is used for extraction, the ratio of the dye plant raw material powder to ethanol is 1:5-1:10, more preferably 1:5-1:8.

[0019] According to a specific embodiment of the present invention, preferably, in step two, when ethanol is used for extraction, the extraction time is 2-8 hours, more preferably 2-6 hours, and even more preferably 4-6 hours.

[0020] According to a specific embodiment of the present invention, preferably, in step three, when water is used for extraction, the ratio of the desugared dye plant material to water is 1:5-1:10.

[0021] According to a specific embodiment of the present invention, preferably, in step three, when water is used for extraction, the extraction temperature is 80-120°C.

[0022] According to a specific embodiment of the present invention, preferably, in step three, when water is used for extraction, the extraction time is 2-8 hours, more preferably 4-8 hours, and even more preferably 4-6 hours.

[0023] According to a specific embodiment of the present invention, preferably, in step four, the specific gravity of the concentrated extract is 1.03-1.13, more preferably 1.05-1.1.

[0024] According to a specific embodiment of the present invention, preferably, in step four, the paste is selected from one or more of maltodextrin, xanthodextrin, and β-cyclodextrin.

[0025] According to a specific embodiment of the present invention, preferably, in step four, the amount of dextrin added is 1%-20% of the final dye powder content, more preferably 5.0-10.0%. During the preparation process, a certain amount of liquid can be dried in advance, and the weight of the solid obtained after drying can be measured. Then, the weight of the effective substance in the extract, i.e., the final dye powder content, can be calculated by combining the pre-weighed amount and the total liquid volume.

[0026] According to a specific embodiment of the present invention, preferably, the flow rate of the spray dryer is 10 kg / h-100 kg / h (more preferably 30 kg / h-80 kg / h), the inlet air temperature is 120-200℃ (more preferably 120-180℃), the tower temperature is 70-110℃ (more preferably 80-100℃), and the outlet air temperature is 60-100℃ (more preferably 70-90℃).

[0027] The present invention also provides a dye powder, which is obtained by the powdering method of the dye plant extract provided by the present invention; preferably, the total sugar content of the dye powder is less than 6.0%, more preferably 2.0-5.9%.

[0028] The present invention also provides a method for dyeing textiles, comprising:

[0029] The steps for dyeing textiles using dye powder obtained by the dye plant extract powdering method of the present invention include: firstly, using dye powder obtained by the dye plant extract powdering method of the present invention, and then using the obtained dye powder for dyeing.

[0030] According to a specific embodiment of the present invention, preferably, the fibers used in the textile include natural fibers and / or chemical fibers; more preferably, the natural fibers include one or more combinations of cotton, linen, silk, and wool; even more preferably, the chemical fibers include one or more combinations of acrylic, viscose, modal, spandex, nylon, and polyester.

[0031] According to a specific embodiment of the present invention, preferably, the textile is loose fiber, fabric, or garment; more preferably, the textile is garment.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The technical solution provided by this invention uses ethanol as a solvent when extracting plant waste extracts. Under high temperature and alkaline conditions, large molecule sugars are converted into small molecule sugars and dissolved in ethanol for removal. This greatly reduces the sugar impurity content in pigments and dyes during subsequent aqueous solution extraction. With the help of dextrin, the problem of extract sticking to the wall of the drying tower during spray drying can be significantly improved. In addition, the plant extracts prepared by this method are not prone to moisture absorption and clumping during storage and use, have better stability, and a longer shelf life, making them highly valuable for application. Attached Figure Description

[0034] Figure 1 The image shows the appearance of the pomegranate peel pigment dye product obtained in Example 1.

[0035] Figure 2 The image shows the appearance of the walnut green husk pigment dye product obtained in Example 2.

[0036] Figure 3 The image shows the appearance of the finished T-shirt dyed with pomegranate peel pigment obtained in Example 4.

[0037] Figure 4 The image shows the appearance of the finished T-shirt dyed with walnut green husk pigment obtained in Example 5.

[0038] Figure 5 This is an image showing the appearance of the pomegranate peel pigment dye product prepared in Comparative Example 1 when it adheres to the wall.

[0039] Figure 6 This is a comparison diagram showing the placement effects of the pomegranate peel pigment dyes prepared in Example 1 and Comparative Example 1.

[0040] Figure 7 The image shows the appearance of the walnut green skin pigment dye product prepared in Comparative Example 2, which cannot be powdered.

[0041] Figure 8 This is a picture showing the effect of the finished pomegranate peel pigment dye prepared in Comparative Example 3 after being placed in the soil. Detailed Implementation

[0042] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0043] Example 1

[0044] This embodiment provides a method for preparing powder from pomegranate peel plant extract, wherein the powder preparation method includes the following specific steps:

[0045] Step 1: Weigh an appropriate amount of dried pomegranate peel raw material, grind it into powder using a traditional Chinese medicine pulverizer, and then sieve it through an 80-mesh sieve to ensure consistency, thus obtaining pomegranate peel raw material powder.

[0046] Step 2: Using 80% ethanol as a solvent, mix it with pomegranate peel powder at a material-to-liquid ratio of 1:8. Add sodium hydroxide to adjust the pH to 12. Treat at 80℃ for 6 hours. After the reaction is complete, collect the ethanol solution into a storage tank to complete the sugar removal treatment of the plant. Subsequently, recover the ethanol and solid residue sugars by distillation. The remaining solid in the storage tank is the pomegranate peel raw material after the sugar removal treatment.

[0047] Step 3: Using water as a solvent, mix the pomegranate peel raw material that has undergone sugar removal treatment with water at a material-to-liquid ratio of 1:5, extract at 100℃ for 4 hours to complete the extraction of pigments and dyes, and then pump the extract into a concentration tank.

[0048] Step 4: Concentrate the extract to a specific gravity of 1.08 in a concentration tank, and then add 10% dextrin to obtain the concentrated extract.

[0049] Step 5: The concentrated extract is powdered using spray drying. The spray drying flow rate is 50 kg / h, the inlet air temperature is 180℃, the tower temperature is 100℃, and the outlet air temperature is 90℃. The powder in the collection tank is the pomegranate peel pigment dye. Its total sugar content, determined by the phenol-sulfuric acid method, is 5.9%.

[0050] Figure 1 This is an image showing the appearance of the pomegranate peel pigment dye product obtained in Example 1. Figure 1 It can be seen that the pomegranate peel pigment dye product prepared in this embodiment has uniform particle size and good dispersibility, without any problems such as clumping, and the color of the dye is earthy yellow.

[0051] Example 2

[0052] This embodiment provides a method for preparing powder from walnut green husk plant extract, wherein the powder preparation method includes the following specific steps:

[0053] Step 1: Weigh an appropriate amount of dried walnut husk raw material, grind it into powder using a traditional Chinese medicine pulverizer, and then sieve it through a 100-mesh sieve to ensure consistency, thus obtaining walnut husk raw material powder.

[0054] Step 2: Using anhydrous ethanol as a solvent, mix it with walnut green husk powder at a material-to-liquid ratio of 1:5. Add sodium hydroxide to adjust the pH to 13. Treat at 80℃ for 4 hours. After the reaction is complete, collect the ethanol solution into a storage tank to complete the sugar removal treatment of the plant. Subsequently, recover the ethanol and solid residue sugars by distillation. The remaining solid in the storage tank is the pomegranate peel raw material after the sugar removal treatment.

[0055] Step 3: Using water as a solvent, mix the pomegranate peel raw material that has undergone sugar removal treatment with water at a material-to-liquid ratio of 1:10, extract at 100℃ for 8 hours to complete the extraction of pigments and dyes, and then pump the extract into a concentration tank.

[0056] Step 4: Concentrate the extract to a specific gravity of 1.10 in a concentration tank, and then add 5% maltodextrin to obtain the concentrated extract.

[0057] Step 5: The concentrated extract is powdered using spray drying. The spray drying flow rate is 30 kg / h, the inlet air temperature is 140℃, the tower temperature is 90℃, and the outlet air temperature is 80℃. The powder in the collection tank is the walnut green husk pigment dye. Its total sugar content, determined by the phenol-sulfuric acid method, is 2.3%.

[0058] Figure 2 This is an image showing the appearance of the walnut green husk pigment dye product obtained in Example 2. Figure 2 It can be seen that the walnut green skin pigment dye product prepared in this embodiment has uniform particle size and good dispersibility, without any problems such as clumping, and the dye color is brownish-gray.

[0059] Example 3

[0060] This embodiment provides a method for preparing grape seed plant extract into powder, wherein the powder preparation method includes the following specific steps:

[0061] Step 1: Weigh an appropriate amount of dried grape seed raw material, grind it into powder using a traditional Chinese medicine pulverizer, and then sieve it through a 60-mesh sieve to ensure consistency, thus obtaining grape seed raw material powder.

[0062] Step 2: Using 60% ethanol as a solvent, mix it with grape seed powder at a material-to-liquid ratio of 1:8. Add sodium hydroxide to adjust the pH to 11 and treat at 80℃ for 2 hours. After the reaction is complete, collect the ethanol solution into a storage tank to complete the sugar removal treatment of the plant. Subsequently, the ethanol and solid residue sugars are recovered by distillation. The remaining solid in the storage tank is the grape seed raw material after the sugar removal treatment.

[0063] Step 3: Using water as a solvent, mix the grape seed raw material that has undergone sugar removal treatment with water at a material-to-liquid ratio of 1:5, extract at 100℃ for 4 hours to complete the extraction of pigments and dyes, and then pump the extract into a concentration tank.

[0064] Step 4: Concentrate the extract to a specific gravity of 1.05 in a concentration tank, and then add a mixture of xanthodextrin and β-cyclodextrin in a mass ratio of 1:1, with a total amount of 8%, to obtain the concentrated extract.

[0065] Step 5: The concentrated extract is powdered using spray drying. The spray drying flow rate is 80 kg / h, the inlet air temperature is 120℃, the tower temperature is 80℃, and the outlet air temperature is 70℃. The powder in the collection tank is the grape seed pigment dye. Its total sugar content, determined by the phenol-sulfuric acid method, is 3.1%.

[0066] Example 4

[0067] This embodiment provides a dyeing method and fabric based on pomegranate peel plant extract, wherein the powder preparation method includes the following specific steps:

[0068] Step 1: Pre-treatment of pure cotton T-shirts. The pre-treatment process is as follows: Sodium carbonate (5g / L, based on the volume of the solvent in the pre-treatment solution, solvent is water) and hydrogen peroxide (4g / L, based on the volume of the solvent in the pre-treatment solution, solvent is water) are used to treat at 90℃ for 10-20 minutes. Then, the pure cotton T-shirts are subjected to cationic modification treatment using chitosan. The amount of chitosan is 10g / L (based on the volume of the solvent in the cationic modification treatment solution, solvent is water), the temperature is 80℃, and the time is 1 hour.

[0069] Step 2: The cationic pure cotton T-shirts were dyed with natural dyes in a vat. The natural dye was the pomegranate peel pigment dye from Example 1, and the amount of pomegranate peel pigment dye used was 2% owf. The reaction temperature was 60°C. o C. The processing time is 2 hours, and the dyed T-shirt is obtained.

[0070] Step 3: Wash the dyed T-shirts obtained in Step 2, soften them (process: softener dosage is 3-5g / L, acetic acid is used to adjust the pH value to about 5.5, temperature is 40-50℃, time is 10-30min), and dry them to obtain the finished dyed T-shirts.

[0071] Figure 3 This is an image showing the appearance of the finished T-shirt dyed with pomegranate peel pigment obtained in Example 4. Figure 3 It can be seen that the T-shirts obtained in this embodiment have a uniform dyeing effect, a deep and distinctive color, and a color fastness that meets basic wearing performance requirements.

[0072] The color fastness test data are shown in Table 1.

[0073] Example 5

[0074] This embodiment provides a dyeing method and fabric based on walnut green husk plant extract, wherein the powder preparation method includes the following specific steps:

[0075] Step 1: Pre-treatment of polyester-cotton (20% polyester content) blended T-shirts. The pre-treatment process is as follows: Sodium carbonate (5g / L, based on the volume of the solvent in the pre-treatment solution, solvent is water) and hydrogen peroxide (4g / L, based on the volume of the solvent in the pre-treatment solution, solvent is water) are used to treat the T-shirts at 90℃ for 10-20 minutes. Then, chitosan is used to perform cationic modification treatment on the blended T-shirts. The chitosan dosage is 20g / L (based on the volume of the solvent in the cationic modification treatment solution, solvent is water), the temperature is 90℃, and the time is 2 hours.

[0076] Step Two: The above-mentioned cationic blended T-shirts are dyed with natural dyes in a vat. The natural dye is the walnut green husk pigment dye from Example 1, with an amount of 6% owf, and the reaction temperature is 800°C. o C. The processing time is 1 hour, and the dyed T-shirt is obtained.

[0077] Step 3: Wash the dyed T-shirts obtained in Step 2, soften them (process: softener 3-5g / L, acetic acid to adjust the pH value to about 5.5, temperature 40-50℃, time 10-30min), and dry them to obtain the finished dyed T-shirts.

[0078] Figure 4 This is an image showing the appearance of the T-shirt dyed with walnut green husk pigment obtained in Example 5. Figure 4 It can be seen that the T-shirts obtained in this embodiment have a uniform dyeing effect, a deep and distinctive color, and a color fastness that meets basic wearing performance requirements.

[0079] The color fastness test data are shown in Table 1.

[0080] Table 1

[0081]

[0082] As can be seen from the test data recorded in Table 1, dyeing with the dye obtained by the method of the present invention can achieve high color fastness.

[0083] Comparative Example 1

[0084] This comparative example provides a method for preparing a powder from pomegranate peel plant extract, wherein the powder preparation method includes the following specific steps:

[0085] Step 1: Weigh an appropriate amount of dried pomegranate peel raw material (same as in Example 1), grind and pulverize it using a traditional Chinese medicine pulverizer, and then sieve it through an 80-mesh sieve to ensure consistency, thereby obtaining pomegranate peel raw material powder.

[0086] Step 2: Using water as a solvent, mix pomegranate peel powder with water at a material-to-liquid ratio of 1:5, extract at 100℃ for 4 hours to complete the extraction of pigments and dyes, and then pump the extract into a concentration tank.

[0087] Step 4: Concentrate the extract in a concentration tank until the specific gravity is 1.08 to obtain the concentrated extract.

[0088] Step 5: The concentrated extract is powdered using spray drying. The spray drying flow rate is 50 kg / h, the inlet air temperature is 180℃, the tower temperature is 100℃, and the outlet air temperature is 90℃. The powder in the collection tank is the pomegranate peel pigment dye. Its total sugar content, determined by the phenol-sulfuric acid method, is 61.2%.

[0089] Figure 5 This is an image showing the finished product of the pomegranate peel pigment dye prepared in Comparative Example 1. Figure 5 It can be seen that the pomegranate peel pigment dye prepared in this comparative example has serious adhesion to the equipment wall, which makes it difficult to collect, affecting the final dye yield and increasing the cost of dye production.

[0090] Experimental Example

[0091] The pomegranate peel pigment dyes of Example 1 and Comparative Example 1 were placed in aluminum foil and placed in an air humidity of 70-80% for 1 day and 3 days, respectively.

[0092] Figure 6 The images show the effects of placing the pomegranate peel pigment dyes prepared in Example 1 and Comparative Example 1. The left image shows the effect after 1 day of placement, and the right image shows the effect after 3 days of placement.

[0093] Depend on Figure 6 The results show that the pomegranate peel pigment dye prepared in Example 1 absorbs moisture slowly in the air. After 3 days, it absorbs moisture slightly and forms small hard lumps, which can be ground into powder again. However, the pomegranate peel pigment dye prepared in Comparative Example 1 absorbs moisture quickly in the air and becomes a soft, chewy lump after 1 day. It cannot be ground into powder again, and it is difficult to weigh accurately during use, which affects the subsequent dyeing effect.

[0094] Comparative Example 2

[0095] This comparative example provides a method for preparing powder from walnut green husk plant extract, wherein the powder preparation method includes the following specific steps:

[0096] Step 1: Weigh an appropriate amount of dried walnut green husk raw material (same as in Example 2), grind and pulverize it using a traditional Chinese medicine pulverizer, and then sieve it through a 100-mesh sieve to ensure consistency, thereby obtaining walnut green husk raw material powder.

[0097] Step 2: Using water as a solvent, mix it with walnut green skin powder at a material-to-liquid ratio of 1:10, extract at 100℃ for 8 hours to complete the extraction of pigments and dyes, and then pump the extract into a concentration tank.

[0098] Step 4: Concentrate the extract to a specific gravity of 1.10 in a concentration tank to obtain the concentrated extract.

[0099] Step 5: The concentrated extract is powdered using spray drying. The spray drying flow rate is 30 kg / h, the inlet air temperature is 140℃, the tower temperature is 90℃, and the outlet air temperature is 80℃. The powder in the collection tank is the walnut green husk pigment dye. Its total sugar content, determined by the phenol-sulfuric acid method, is 29.1%.

[0100] Figure 7 This is an image showing the appearance of the walnut green husk pigment dye product obtained in Comparative Example 2. Figure 7 It can be seen that the walnut green skin pigment dye prepared in this comparative example cannot be powdered in the collection tank, and the resulting sticky lumps cannot be collected, which may seriously clog the equipment pipeline and damage the equipment.

[0101] Comparative Example 3

[0102] This comparative example provides a method for preparing a powder from pomegranate peel plant extract, wherein the powder preparation method includes the following specific steps:

[0103] Step 1: Weigh an appropriate amount of dried pomegranate peel raw material (same as in Example 1), grind and pulverize it using a traditional Chinese medicine pulverizer, and then sieve it through an 80-mesh sieve to ensure consistency, thereby obtaining pomegranate peel raw material powder.

[0104] Step 2: Using anhydrous ethanol as a solvent, mix it with pomegranate peel powder at a material-to-liquid ratio of 1:5, and extract at 100℃ for 4 hours to complete the extraction of pigments and dyes. Then, pump the extract into a concentration tank.

[0105] Step 4: Concentrate the extract to a specific gravity of 1.08 in a concentration tank, then add 8% β-cyclodextrin to obtain the concentrated extract.

[0106] Step 5: The concentrated extract is powdered using spray drying. The spray drying flow rate is 50 kg / h, the inlet air temperature is 180℃, the tower temperature is 100℃, and the outlet air temperature is 90℃. The powder in the collection tank is the pomegranate peel pigment dye. Its total sugar content, determined by the phenol-sulfuric acid method, is 44.6%.

[0107] Figure 8 The images show the appearance of the pomegranate peel pigment dye product prepared in Comparative Example 3 after 1 day (left image) and 3 days (right image).

[0108] Depend on Figure 8 The results show that the pomegranate peel pigment dye prepared in Comparative Example 3 had a slower moisture absorption rate in the air in the first day compared to Comparative Example 1, and slightly clumped. However, after 3 days, it turned into a soft, chewy lump that could not be ground into powder again, making it difficult to weigh during use and greatly reducing the accuracy of weighing. Its storage stability was far lower than that of Example 1.

Claims

1. A method for preparing a powder from a dye plant extract, wherein, Includes the following steps: Step 1: Grind the dried dye plant materials into powder, sieve, and obtain dye plant material powder; Step 2: Using ethanol as a solvent and adjusting the pH to alkaline, the dye plant raw material powder is soaked at 70-90℃ under alkaline conditions to extract sugars. After extraction, the ethanol extract is separated, and the remaining solid is the dye plant raw material that has undergone sugar removal treatment. Step 3: Use water as the extraction solvent to extract the dye plant raw material after the sugar removal treatment to obtain the extract; Step 4: Concentrate the extract, and after concentration, add dextrin to obtain the concentrated extract; Step 5: The concentrated extract is made into dye powder by spray drying.

2. The powder preparation method according to claim 1, wherein, The sieve used for sieving has a mesh size of 60-120.

3. The powder preparation method according to claim 1, wherein, The ethanol has a mass fraction of 60%-100%; And / or, the pH value is 10.0-13.0, preferably 11.0-13.0; And / or, the pH value is adjusted by adding sodium hydroxide.

4. The powder preparation method according to claim 1, wherein, The ratio of the dye plant raw material powder to ethanol is 1:5-1:10; The extraction time is 2-8 hours.

5. The powder preparation method according to claim 1, wherein, The ratio of the dye plant raw material to water after the sugar removal treatment is 1:5-1:10; The extraction temperature is 80-120℃, and the extraction time is 2-8 hours.

6. The powder preparation method according to claim 1, wherein, The specific gravity of the concentrated extract is 1.03-1.

13.

7. The powder preparation method according to claim 1, wherein, The paste is selected from one or more of maltodextrin, xanthodextrin, and β-cyclodextrin; And / or, the amount of dextrin added is 1%-20% of the final dye powder content.

8. The powder preparation method according to claim 1, wherein, The spray drying process has a flow rate of 10 kg / h-100 kg / h, an inlet air temperature of 120-200℃, an internal tower temperature of 70-110℃, and an outlet air temperature of 60-100℃.

9. A dye powder obtained by the powdering method of the dye plant extract according to any one of claims 1-8; preferably, the total sugar content of the dye powder is 6.0% or less, more preferably 2.0-5.9%.

10. A method for dyeing textiles, comprising: The step of dyeing textiles using the dye powder according to claim 9; Preferably, the fibers used in the textile include natural fibers and / or chemical fibers; More preferably, the natural fiber includes one or more of cotton, linen, silk, and wool; More preferably, the chemical fiber includes one or more of acrylic, viscose, modal, spandex, nylon, and polyester.

11. The textile dyeing method according to claim 10, wherein, The textile is loose fiber, fabric, or garment; Preferably, the textile is a garment.

Images