Production method of plant indigo Lyocell fiber

Abstract

The invention discloses a plant indigo Lyocell fiber production method, and belongs to the technical field of lyocell fiber preparation and the field of biodegradable materials.The plant indigo Lyocell fiber production method comprises the following steps that SS1, a certain amount of plant indigo dye is taken and added into a grinding machine to be ground, and grinding is completed when the dye particle size ranges from 100 nm to 150 nm; step SS2, adding the ground dye into an NMMO aqueous solution with the mass fraction of 50-65%, and fully stirring on an electric stirrer to obtain a solution 1; step SS3, mixing and stirring the solution 1 and pulp to obtain a mixed system 1; and step SS4, concentrating the mixed system 1 until the mass fraction of the NMMO is 86-88% to obtain a spinning solution, and then spinning, washing, cutting, washing, oiling and drying to obtain the indigo Lyocell fiber. By reasonably adding the plant indigo dye and optimizing the process, the rheological behavior of the spinning solution is improved, the stability of the plant indigo in a spinning solution system is improved, and the available range of the lyocell fiber is widened.

Description

Technical Field

[0001] The invention relates to a method for producing plant indigo Lyocell fiber by using plant dyes, and belongs to the technical field of Lyocell fiber preparation and the field of biodegradable materials. Background Art

[0002] Lyocell fiber production technology has gradually matured, and research on differentiated products has gradually deepened. For colored fiber products, companies such as Lenzing have already produced related products, indicating that the market prospects for colored Lyocell fibers are still relatively broad.

[0003] The comparative document 1 has a public application number of 202011087290.X and is named "Black lyocell fabric made by dyeing with plant dye black sycamore and its preparation method". The technical problem it solves is: how to use natural dyes to dye textiles, reduce the potential harm of chemical dyes to the human body, and at the same time improve color fastness and color fastness to washing and weathering, and how to develop and utilize lyocell fiber as a carrier for natural dyes to improve the utilization rate and dyeing effect of natural dyes.

[0004] Comparative document 2 has a public application number of 201811629802.3 and is an invention patent application entitled “A method for dyeing lyocell fibers”. The technical problem it solves is: how to use plant dyes to develop high-quality functional fibers and solve their color fastness problems, especially light fastness problems.

[0005] Comparative document 3 has a public application number of 201910463379.2 and is an invention patent application entitled "A lyocell fiber fabric dyed with natural dyes and a preparation method thereof". The technical problem it solves is: how to effectively bring natural dyes close to lyocell fibers and react with them to achieve effective dyeing of lyocell fibers with natural dyes. Summary of the invention

[0006] The purpose of the present invention is to overcome the technical defects of the prior art and propose a method for producing plant indigo Lyocell fiber, mainly to produce indigo Lyocell fiber. Downstream enterprises can use this color fiber for product development and production, which can save a lot of water and dyeing costs, and secondly increase the category of Lyocell fiber products on the market.

[0007] The present invention specifically adopts the following technical solution: a method for producing plant indigo Lyocell fiber, comprising the following steps:

[0008] Step SS1: adding a certain amount of plant indigo dye into a grinder for grinding, so that the dye particles have a particle size of 100-150 nm;

[0009] Step SS2: adding the ground dye to a 50-65% by mass NMMO aqueous solution, and stirring the mixture on an electric stirrer to obtain a solution 1;

[0010] Step SS3: mixing solution 1 with pulp and stirring to obtain a mixed system 1;

[0011] Step SS4: Concentrate the mixed system 1 to a mass fraction of NMMO of 86-88% to obtain a spinning solution, and then spin, wash, cut, wash, oil, and dry to obtain the indigo Lyocell fiber.

[0012] As a preferred embodiment, in step SS2, the stirring speed is 800 r / min and the stirring time is 20 min.

[0013] As a preferred embodiment, the step SS3 specifically comprises: mixing the solution 1 with the pulp, stirring for 30-60 minutes at 80-90° C., to obtain a mixed system 1.

[0014] As a preferred embodiment, the step SS4 specifically comprises: concentrating the mixed system 1 at 100-120° C. until the mass fraction of NMMO is 86-88%.

[0015] As a preferred embodiment, the cellulose content of the pulp in the spinning solution in step SS4 is 11-12 wt%.

[0016] As a preferred embodiment, the step SS4 specifically also includes: conveying the slurry to the screw through pressure boosting, then to the metering pump, and then to the spinneret for spraying out, and then winding, bundling, and stretching the filaments after passing through a coagulation bath, using three-pass stretching during the stretching process, and finally cutting the fiber bundle.

[0017] As a preferred embodiment, the conditions of the coagulation bath are: mass concentration 20%, temperature 20°C.

[0018] As a preferred embodiment, the stretching temperature of the stretching process is 30-35°C, and the stretching multiple is 2-3.

[0019] As a preferred embodiment, the fiber bundle is cut at a knife speed of 40 m / min and a length of 33 mm.

[0020] As a preferred embodiment, the linear density of the plant indigo Lyocell fiber is 1.0-2.5 dtex, and the dry breaking strength is higher than 3.2 cN / dtex.

[0021] The beneficial effects achieved by the present invention are as follows: the present invention proposes a method for preparing plant indigo Lyocell fiber, firstly, experimental screening is carried out on plant indigo dyes from different manufacturers, and then a suitable dye is selected to produce the plant indigo Lyocell fiber, wherein the fiber linear density is between 1.0 and 2.5 dtex, and the dry breaking strength is higher than 3.2 cN / dtex; at the same time, the present invention improves the rheological behavior of the spinning solution by reasonably adding the amount of plant indigo dye and optimizing the process, solves the key problem of the stability of plant indigo in the spinning solution system, broadens the available scope of Lyocell fiber, and realizes the low-carbon, environmentally friendly and sustainable development function of the plant indigo Lyocell fiber. DETAILED DESCRIPTION

[0022] The present invention is further described below. The following examples are only used to more clearly illustrate the technical solution of the present invention, and are not intended to limit the protection scope of the present invention.

[0023] Example 1: The present invention provides a method for producing plant indigo Lyocell fiber, comprising the following steps:

[0024] Step SS1: adding a certain amount of plant indigo dye into a grinder for grinding, so that the dye particles have a particle size of 100-150 nm;

[0025] Step SS2: adding the ground dye to a 50% by mass NMMO aqueous solution, and stirring the mixture on an electric stirrer at a stirring speed of 800 r / min for 20 min to obtain a solution 1;

[0026] Step SS3: mixing solution 1 with pulp, stirring at 80-90° C. for 30-60 min to obtain a mixed system 1;

[0027] Step SS4: The mixed system 1 is concentrated at 100-120°C to a mass fraction of NMMO of 86-88% to obtain a spinning solution, and the slurry is conveyed to the screw by pressurization, and then to the metering pump, and then to the spinneret for spraying, and the filaments are wound, bundled, and stretched after passing through a coagulation bath. Three stretchings are used during the stretching process, and finally the fiber bundle is cut; the slurry cellulose content in the spinning solution in the step SS4 is 11-12wt%; the conditions of the coagulation bath are: mass concentration 20%, temperature 20°C. The stretching temperature of the stretching process is 30-35°C, and the stretching multiple is 2-3. The knife speed for cutting the fiber bundle is 40m / min, and the length is 33mm; the linear density of the plant indigo Lyocell fiber is 1.0-2.5dtex, and the dry breaking strength is higher than 3.2cN / dtex.

[0028] Example 2: The present invention provides a method for producing plant indigo Lyocell fiber, comprising the following steps:

[0029] Step SS1: adding a certain amount of plant indigo dye into a grinder for grinding, so that the dye particles have a particle size of 100-150 nm;

[0030] Step SS2: adding the ground dye to a 55% by mass NMMO aqueous solution, and stirring the mixture on an electric stirrer at a stirring speed of 800 r / min for 20 min to obtain a solution 1;

[0031] Step SS3: mixing solution 1 with pulp, stirring at 80-90° C. for 30-60 min to obtain a mixed system 1;

[0032] Step SS4: The mixed system 1 is concentrated at 100-120°C to a mass fraction of NMMO of 86-88% to obtain a spinning solution, and the slurry is conveyed to the screw by pressurization, and then to the metering pump, and then to the spinneret for spraying, and the filaments are wound, bundled, and stretched after passing through a coagulation bath. Three stretchings are used during the stretching process, and finally the fiber bundle is cut; the slurry cellulose content in the spinning solution in the step SS4 is 11-12wt%; the conditions of the coagulation bath are: mass concentration 20%, temperature 20°C. The stretching temperature of the stretching process is 30-35°C, and the stretching multiple is 2-3. The knife speed for cutting the fiber bundle is 40m / min, and the length is 33mm; the linear density of the plant indigo Lyocell fiber is 1.0-2.5dtex, and the dry breaking strength is higher than 3.2cN / dtex.

[0033] Example 3: The present invention provides a method for producing plant indigo Lyocell fiber, comprising the following steps:

[0034] Step SS1: adding a certain amount of plant indigo dye into a grinder for grinding, so that the dye particles have a particle size of 100-150 nm;

[0035] Step SS2: adding the ground dye to a 60% by mass NMMO aqueous solution, and stirring the mixture on an electric stirrer at a stirring speed of 800 r / min for 20 min to obtain a solution 1;

[0036] Step SS3: mixing solution 1 with pulp, stirring at 80-90° C. for 30-60 min to obtain a mixed system 1;

[0037] Step SS4: The mixed system 1 is concentrated at 100-120°C to a mass fraction of NMMO of 86-88% to obtain a spinning solution, and the slurry is conveyed to the screw by pressurization, and then to the metering pump, and then to the spinneret for spraying, and the filaments are wound, bundled, and stretched after passing through a coagulation bath. Three stretchings are used during the stretching process, and finally the fiber bundle is cut; the slurry cellulose content in the spinning solution in the step SS4 is 11-12wt%; the conditions of the coagulation bath are: mass concentration 20%, temperature 20°C. The stretching temperature of the stretching process is 30-35°C, and the stretching multiple is 2-3. The knife speed for cutting the fiber bundle is 40m / min, and the length is 33mm; the linear density of the plant indigo Lyocell fiber is 1.0-2.5dtex, and the dry breaking strength is higher than 3.2cN / dtex.

[0038] Example 4: The present invention provides a method for producing plant indigo Lyocell fiber, comprising the following steps:

[0039] Step SS1: adding a certain amount of plant indigo dye into a grinder for grinding, so that the dye particles have a particle size of 100-150 nm;

[0040] Step SS2: adding the ground dye to a 65% by mass NMMO aqueous solution, and stirring the mixture on an electric stirrer at a stirring speed of 800 r / min for 20 min to obtain a solution 1;

[0041] Step SS3: mixing solution 1 with pulp, stirring at 80-90° C. for 30-60 min to obtain a mixed system 1;

[0042] Step SS4: The mixed system 1 is concentrated at 100-120°C to a mass fraction of NMMO of 86-88% to obtain a spinning solution, and the slurry is conveyed to the screw by pressurization, and then to the metering pump, and then to the spinneret for spraying, and the filaments are wound, bundled, and stretched after passing through a coagulation bath. Three stretchings are used during the stretching process, and finally the fiber bundle is cut; the slurry cellulose content in the spinning solution in the step SS4 is 11-12wt%; the conditions of the coagulation bath are: mass concentration 20%, temperature 20°C. The stretching temperature of the stretching process is 30-35°C, and the stretching multiple is 2-3. The knife speed for cutting the fiber bundle is 40m / min, and the length is 33mm; the linear density of the plant indigo Lyocell fiber is 1.0-2.5dtex, and the dry breaking strength is higher than 3.2cN / dtex.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for producing plant indigo Lyocell fiber, characterized in that: The steps include: Step SS1: adding a certain amount of plant indigo dye into a grinder for grinding, so that the dye particles have a particle size of 100-150 nm; Step SS2: adding the ground dye to a 50-65% by mass NMMO aqueous solution, and stirring the mixture on an electric stirrer to obtain a solution 1; Step SS3: mixing solution 1 with pulp and stirring to obtain a mixed system 1; Step SS4: Concentrate the mixed system 1 to a mass fraction of NMMO of 86-88% to obtain a spinning solution, and then spin, wash, cut, wash, oil, and dry to obtain the indigo Lyocell fiber.

2. The method for producing plant indigo Lyocell fiber according to claim 1, characterized in that: In step SS2, the stirring speed is 800 r / min and the stirring time is 20 min.

3. The method for producing plant indigo Lyocell fiber according to claim 1, characterized in that: The step SS3 specifically includes: mixing the solution 1 with the pulp, stirring at 80-90° C. for 30-60 minutes, to obtain a mixed system 1.

4. The method for producing plant indigo Lyocell fiber according to claim 1, characterized in that: The step SS4 specifically comprises: concentrating the mixed system 1 at 100-120° C. until the mass fraction of NMMO is 86-88%.

5. The method for producing plant indigo Lyocell fiber according to claim 4, characterized in that: The cellulose content of the slurry in the spinning solution in step SS4 is 11-12 wt%.

6. The method for producing plant indigo Lyocell fiber according to claim 4, characterized in that: The step SS4 specifically includes: conveying the slurry to the screw by pressurization, then to the metering pump, and then to the spinneret for spraying, and then winding, bundling and stretching the filaments after passing through a coagulation bath, using three-pass stretching during the stretching process, and finally cutting the fiber bundle.

7. The method for producing plant indigo Lyocell fiber according to claim 6, characterized in that: The conditions of the coagulation bath are: mass concentration 20%, temperature 20°C.

8. The method for producing plant indigo Lyocell fiber according to claim 6, characterized in that: The stretching temperature of the stretching process is 30-35° C., and the stretching multiple is 2-3.

9. The method for producing plant indigo Lyocell fiber according to claim 6, characterized in that: The fiber bundle is cut at a knife speed of 40 m / min and a length of 33 mm.

10. The method for producing plant indigo Lyocell fiber according to claim 1, characterized in that: The plant indigo Lyocell fiber has a linear density of 1.0-2.5 dtex and a dry breaking strength higher than 3.2 cN / dtex.