CN112538663A

CN112538663A - Lyocell fiber, Lyocell fiber mask cloth and manufacturing method thereof

Info

Publication number: CN112538663A
Application number: CN202011412852.3A
Authority: CN
Inventors: 王辉忠; 胡向华; 杨翠芳; 顾超; 胡小磊
Original assignee: Shanghai Jisuo Industrial Co ltd
Current assignee: Shanghai Jisuo Industrial Co ltd
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2021-03-23

Abstract

The application relates to the technical field of mask materials, and particularly discloses lyocell fibers, lyocell fiber mask cloth and a manufacturing method thereof. The lyocell fibers of the present application are made by a process comprising the steps of: 1) uniformly mixing a cellulose raw material and a mixed solvent at 50-85 ℃ to prepare a stock solution; the mixed solvent is prepared by mixing the following raw materials in parts by weight: 75-80 parts of N-methylmorpholine-N-oxide, 8-10 parts of cosolvent, 2-5 parts of stabilizer and 10-15 parts of water; the cosolvent is at least one of trimethylphenyl ammonium hydroxide and 3- (trifluoromethyl) phenyl trimethyl ammonium hydroxide; the stabilizer is at least one of propylene glycol alginate and polyoxypropylene polyoxyethylene propylene glycol ether; 2) filtering the stock solution, spinning, and then carrying out coagulating bath forming to obtain the spinning solution. When the lyocell fiber is prepared, the cellulose can be quickly and fully dissolved, and the prepared lyocell fiber has high strength and is easy to degrade.

Description

Lyocell fiber, Lyocell fiber mask cloth and manufacturing method thereof

Technical Field

The application relates to the technical field of mask materials, in particular to lyocell fibers, lyocell fiber mask cloth and a manufacturing method thereof.

Background

Lyocell is a regenerated fiber containing cellulose, which is generally extracted from natural materials, and thus, lyocell has many excellent properties of natural fibers and synthetic fibers, called "tencel", and when used as a clothing fabric, has the advantages of good comfort, good hand feeling, easy dyeing, and the like, and is very environment-friendly. With the continuous optimization of the lyocell fiber production process, the production cost is continuously reduced, the application field of the lyocell fiber is larger and larger, and with the optimization of the processing technology, various high-end functional lyocell fibers are gradually developed and applied.

The mask cloth prepared from the lyocell fibers has the characteristics of high flexibility, high stability and the like, has obvious advantages compared with the cuprammonium fiber mask cloth, and is more and more widely applied to the field of mask manufacturing.

Most of the lyocell fibers at present are prepared by a solvent method, i.e. cellulose is dissolved and then spun. The dissolving capacity of different solvents to cellulose is different, and the Chinese patent application with application publication number CN110172746A discloses a method for preparing lyocell fiber by dissolving cellulose with a novel solvent, which comprises the following steps: (1) preparation of a novel solvent: dissolving LiCl in dimethylacetamide, heating and stirring to dissolve the LiCl, wherein the mass fraction of the LiCl is 5-10%, and preparing to obtain a LiCl/dimethylacetamide mixed solvent, wherein the dissolving temperature is 100-105 ℃, and the dissolving time is 3-4 hours; (2) preparing a spinning solution: dissolving a proper amount of wood pulp cellulose in the LiCl/dimethylacetamide mixed solvent prepared in the step (1), and dissolving the mixture for 4-5 hours in a reaction kettle at 105-120 ℃ by vacuum stirring to prepare a uniform and transparent spinning solution with the mass fraction of 10-20%; (3) spinning of lyocell fibers: adding the spinning solution treated in the step (2) into a screw extruder, further dissolving at 95-110 ℃, filtering, and entering a spinning system, wherein the length of an air gap is 6-9 cm, the spinning speed is 35-50 m/min, the pore diameter of a spinneret plate is 10-110 mu m, and the length of a pore capillary is 300-900 mu m; vertically stretching the sprayed silk in the air, entering a coagulating bath, and coagulating and forming, wherein the coagulating bath is a LiCl/dimethylacetamide mixed solvent prepared in the step (1), and the temperature of the coagulating bath is 3-10 ℃; (4) alcohol washing of the fiber; (5) washing the fiber with water; (6) oiling the fibers; (7) and (5) drying the fibers.

In view of the above-mentioned related art, the inventors believe that the temperature at which cellulose is dissolved in this method is too high, and this tends to affect the degree of hydrolysis after cellulose is dissolved, thereby causing a decrease in the strength of the produced fiber.

Disclosure of Invention

The application provides lyocell fibers, lyocell fiber mask cloth and a manufacturing method thereof, in order to improve the strength of the lyocell fibers.

In a first aspect, the lyocell fiber provided by the present application adopts the following technical scheme:

a lyocell fibre produced by a process comprising the steps of:

1) uniformly mixing a cellulose raw material and a mixed solvent at 50-85 ℃ to prepare a stock solution; the mixed solvent is prepared by mixing the following raw materials in parts by weight: 75-80 parts of N-methylmorpholine-N-oxide, 8-10 parts of cosolvent, 2-5 parts of stabilizer and 10-15 parts of water; the cosolvent is at least one of trimethylphenyl ammonium hydroxide and 3- (trifluoromethyl) phenyl trimethyl ammonium hydroxide; the stabilizer is at least one of propylene glycol alginate and polyoxypropylene polyoxyethylene propylene glycol ether;

2) filtering and spinning the stock solution prepared in the step 1), and then carrying out coagulating bath forming to obtain the spinning solution.

By adopting the technical scheme, when the cellulose raw material is dissolved, the lower temperature is adopted, the hydrolysis degree of the cellulose after the dissolution is reduced, the chain structure of the cellulose is retained to the maximum extent, the cellulose is maintained to have a longer chain length, and the fiber with higher strength is obtained after spinning. The cosolvent and the stabilizer are added into the solvent, so that the dissolving efficiency of the cellulose at a lower temperature can be improved, the viscosity of the N-methylmorpholine-N-oxide at the lower temperature can be reduced, and the spinning solution with the cellulose dissolved fully and uniformly dispersed can be obtained. The cosolvent and the stabilizer also help the mask cloth to improve the degradation speed and are beneficial to environmental protection.

Preferably, the step 1) of uniformly mixing the cellulose raw material and the mixed solvent is to stir for 2 to 3 hours under the condition that the vacuum degree is 0.01 to 0.05 MPa.

Through adopting above-mentioned technical scheme, because the volume of the water that adds in this application is less, has adopted lower dissolving temperature moreover, and the viscosity of miscella is great, stirs under the lower condition of vacuum, can promote the bubble on cellulose raw materials surface and be fully discharged, further improves cellulose dissolving efficiency.

Preferably, the raw materials for preparing the mixed solvent in the step 1) further comprise 2-3 parts by weight of methanol.

By adopting the technical scheme, a small amount of methanol is added into the raw materials of the mixed solvent, so that the dispersibility of the N-methylmorpholine-N-oxide and the cosolvent in the solvent can be greatly changed, the viscosity of the solvent is further reduced, and the dissolving efficiency is further improved.

Preferably, raw materials for preparing the mixed solvent in the step 1) further comprise 5-6 parts by weight of silk fibroin.

By adopting the technical scheme, the silk fibroin is added into the mixed solvent, so that the dissolved cellulose and the dissolved silk fibroin are uniformly mixed together, and then when spinning is carried out, the silk fibroin is mixed in silk threads obtained by spinning, the composite strength of the fibers is improved, the protein content in the fibers is also improved, the obtained fibers are closer to natural silk, and the prepared mask cloth is higher in use comfort level. The silk fibroin is dispersed in the cellulose fiber, so that the prepared fiber is easier to degrade, and the environmental protection of the fiber is enhanced.

Preferably, the filtered stock solution in the step 2) is subjected to defoaming treatment after filtration, and the defoaming treatment is to allow the filtered stock solution to stand at 80-85 ℃ for 12-24 h.

By adopting the technical scheme, as the components added into the mixed solvent are more, a small amount of fine bubbles are still inevitably remained in the spinning solution after the cellulose is dissolved, so that the deaeration treatment is adopted after the filtration to discharge the gas in the solution as much as possible, and the lower temperature is still adopted during the deaeration treatment to reduce the influence of the temperature on the cellulose.

Preferably, the bath liquid adopted in the coagulation bath in the step 2) is prepared by mixing the following raw materials in parts by weight: 10-20 parts of N-methylmorpholine-N-oxide and 70-80 parts of water.

By adopting the technical scheme, a small amount of N-methylmorpholine-N-oxide is added into the bath liquid adopted in the coagulation bath, so that mutual bonding of the silk threads obtained by spinning in the coagulation bath is reduced, residual particles on the surfaces of the silk threads can be removed, and the surface quality of the silk threads is improved.

Preferably, the bath liquid preparation raw materials of the coagulating bath also comprise ethylene glycol and glycerol, and the mass ratio of the ethylene glycol to the glycerol to the N-methylmorpholine-N-oxide is 3-4:6-7: 10-20.

By adopting the technical scheme, the addition of the glycol and the glycerol can reduce the viscosity of the coagulation bath at low temperature, so that the temperature of the coagulation bath can be set lower, and the separation of the silk threads obtained by spinning is facilitated.

Preferably, cleaning is carried out after the coagulating bath is formed in the step 2), and the cleaning solution adopted in the cleaning process is obtained by mixing fatty alcohol and water in a volume ratio of 80-85: 15-20; the aliphatic alcohol is at least one of methanol and ethanol.

By adopting the technical scheme, the N-methylmorpholine-N-oxide and the polyhydric alcohol are added into the bath liquid of the coagulation bath, the bath liquid is cleaned after the coagulation bath, and the cleaning liquid is a mixed liquid of fatty alcohol and water, so that the components of the coagulation bath liquid on the surface of the silk threads can be removed, and the silk threads are prevented from being adhered.

In a second aspect, the present application provides a lyocell fiber mask cloth, which adopts the following technical scheme:

a lyocell fiber mask cloth is prepared from the lyocell fibers.

By adopting the scheme, the lyocell fiber mask cloth is made of lyocell fibers, so that the prepared lyocell fiber mask cloth has higher strength and better comfort level.

In a third aspect, the present application provides a method for manufacturing lyocell fiber mask cloth, which adopts the following technical scheme:

a method for manufacturing lyocell fiber mask cloth comprises the following steps:

s1, carding and laying the lyocell fibers into a fiber web, and then carrying out spunlace treatment, wherein the spunlace treatment comprises five spunlace treatments, and the spunlace pressure of the five spunlace treatments is respectively 0.7-0.9MPa, 5-6MPa, 9-10MPa, 11-13MPa and 15-16 MPa. (ii) a

And S2, drying the fiber web subjected to the spunlace entanglement treatment in the step S1, and carrying out hot rolling and shaping to obtain the fiber web.

By adopting the technical scheme, when the lyocell fibers are made into the mask cloth, the spunlace entanglement treatment is adopted, and the five spunlace treatments are adopted in the spunlace entanglement treatment, so that the lyocell fibers can be fully entangled and cohered, a non-woven fabric containing a large number of fine micropores can be obtained, and the air permeability and the liquid absorption capacity of the mask cloth can be improved.

In summary, the present application has the following beneficial effects:

1. the lyocell fiber is prepared from the cellulose raw material, when the cellulose raw material is dissolved, various components except N-methylmorpholine-N-oxide are added into a solvent, so that the cellulose can be quickly and fully dissolved, the occurrence of 'gel clusters' in stock solution is reduced, the quality of the fiber obtained by spinning is improved, and the prepared lyocell fiber is more uniform and has higher strength. The mixed solvent obtained by compounding the cosolvent, the stabilizer and the N-methylmorpholine-N-oxide can also reduce the dissolving temperature of cellulose, and further improve the quality of the fiber.

2. When the lyocell fiber is prepared, silk fibroin is added into stock solution, a small amount of protein can be introduced into the finally prepared lyocell fiber, the softness of the fiber is improved, the comfort degree of the facial mask cloth prepared from the lyocell fiber is also improved, and the prepared facial mask cloth is easy to degrade and high in environmental friendliness.

3. When the lyocell fiber mask cloth is prepared, the lyocell fibers are subjected to spunlace entanglement treatment, and five spunlace treatments are adopted during the spunlace entanglement treatment, so that the lyocell fibers are fully entangled, a large number of fine micropores are formed in the mask cloth, and the moisture retention of the mask cloth is improved.

Detailed Description

The present application will be described in further detail with reference to examples.

When the lyocell fiber is prepared, 1-2 parts by weight of activated carbon is also included in the raw materials for preparing the mixed solvent.

Preferably, the silk fibroin added to the mixed solvent is prepared from silkworm cocoon. Specifically, the silk fibroin is prepared by a method comprising the following steps: adding degummed silkworm cocoon into LiBr solution with concentration of 10mol/L, stirring uniformly, dialyzing with dialysis bag with molecular weight cutoff of 3500 for 5 days to obtain silk fibroin suspension, freeze drying at-40 deg.C, and grinding to obtain silk fibroin powder. The silk fibroin powder is added when preparing the mixed solvent, or can be added into the solvent together with the cellulose raw material according to specific conditions.

The cellulose raw material is fir wood pulp or cotton pulp, or is prepared from one of fir wood pulp and cotton pulp. The preparation method comprises adding lignum seu ramulus Cunninghamiae Lanceolatae pulp or cotton pulp into 15% sodium hydroxide solution, soaking at 50 deg.C for 50min, filtering, washing with water, drying, and pulverizing to obtain cellulose raw material. Preferably, the polymerization degree of the fir wood pulp and the cotton pulp is 650.

The mass ratio of the cellulose raw material to the mixed solvent is 1: 8-10. Preferably, the mass ratio of the cellulose raw material to the mixed solvent is 1: 10.

The vacuum degree during the defoaming treatment is 0.01-0.05 MPa.

Preferably, the bath liquid of the coagulating bath is prepared by mixing N-methylmorpholine-N-oxide, water, glycol and glycerol in a mass ratio of 10:80:4: 6. The temperature of the coagulation bath is 0-20 ℃. Preferably, the temperature of the coagulation bath is 2-10 ℃.

Preferably, the cleaning liquid used for cleaning after coagulation bath is obtained by mixing ethanol, methanol and water at a volume ratio of 60:25: 15. After cleaning, the cleaned silk threads are firstly soaked in water with the temperature of 80-85 ℃ for 1-2h and then soaked in water with the temperature of 5-10 ℃ for 3-5 h.

When the lyocell fiber is prepared, the spinning speed is 15-25m/min during spinning. The aperture of the spinneret plate is 15-30 mu m.

When the lyocell fiber mask cloth is prepared, the lyocell fibers are prepared by adopting long fibers or cutting the lyocell fibers into short fibers.

The temperature during hot rolling and shaping is 70-80 ℃, and the pressure of hot rolling and shaping is 0.05-0.1 MPa.

Soaking the dried fiber web in a first soaking solution for 5-10min before hot rolling and shaping, then drying, then soaking in a second soaking solution for 30-50min, and drying; the first soaking solution comprises a silane coupling agent, wherein the silane coupling agent is any one of gamma-aminopropyltrimethoxysilane and N-beta (aminoethyl) -gamma-aminopropyltrimethoxysilane; the second soaking solution comprises at least one of maleic anhydride, pyromellitic anhydride, dimethyl silicone oil and dimethyl sulfoxide. Preferably, the first soaking solution is soaked for 5min, and the second soaking solution is soaked for 30 min. The first soaking solution is obtained by mixing a silane coupling agent, methanol, ethanol and water according to the mass ratio of 1-3:15-20:30-40: 5-8. The second soaking solution is obtained by mixing any one of maleic anhydride and pyromellitic dianhydride with dimethyl silicone oil and dimethyl sulfoxide according to the mass ratio of 1-2:0.3-0.5: 20-35. Drying at 80-90 deg.C for 20-30min after soaking in the first soaking solution, and drying at 60-70 deg.C for 40-50min after soaking in the second soaking solution. Preferably, drying is carried out at 80 ℃ for 30min and at 70 ℃ for 40 min.

Examples

Example 1

The lyocell fiber of this example was prepared by a process comprising the steps of:

1) preparation of stock solutions

Uniformly mixing N-methylmorpholine-N-oxide, a cosolvent, a stabilizer and water in a mass ratio of 75:8:2:15 to prepare a mixed solvent, adding the mixed solvent into a vacuum dissolution kettle, adding a cellulose raw material, and stirring for 3 hours at 85 ℃ and under the vacuum degree of 0.05MPa to prepare a stock solution; the cellulose raw material is fir wood pulp with the polymerization degree of 650, the cosolvent is trimethyl phenyl ammonium hydroxide, and the stabilizer is propylene glycol alginate; the mass ratio of the cellulose raw material to the mixed solvent is 1: 10;

2) spinning

Filtering the stock solution prepared in the step 1), and then placing the filtered stock solution into a vacuum oven at 85 ℃ for standing and defoaming for 12 hours;

spinning the defoamed stock solution at a spinning speed of 25m/min, wherein the aperture of a spinneret plate is 30 mu m;

3) coagulating bath

The silk threads obtained after spinning enter a coagulating bath groove to be coagulated, bath liquid used by the coagulating bath is obtained by mixing N-methylmorpholine-N-oxide (NMMO) and water in a mass ratio of 20:70, and the temperature of the coagulating bath is 20 ℃;

4) cleaning of

Immersing the obtained silk thread after coagulation bath into cleaning liquid for soaking and cleaning for 3h, wherein the cleaning liquid is obtained by mixing ethanol and water in a volume ratio of 80: 20;

and soaking the cleaned silk thread in water at 80 ℃ for 2h, then soaking in water at 10 ℃ for 5h, taking out, and drying to obtain the lyocell fiber.

The lyocell fiber mask cloth of this example was made of the lyocell fibers described above.

The method for manufacturing the lyocell fiber mask cloth comprises the following steps:

s1, carding and laying the lyocell fibers into a fiber web, wherein the quantitative amount of the fiber web is 40g/m²Then carrying out spunlace entanglement treatment, wherein the spunlace entanglement treatment adopts five spunlace treatments, namely drum spunlace, flat-mesh spunlace, drum spunlace and flat-mesh spunlace, and the spunlace pressure of the five spunlace treatments is respectively 0.7MPa, 5MPa, 9MPa, 10MPa and 12 MPa;

s2, drying the fiber web subjected to the spunlace entanglement treatment, and then carrying out hot rolling setting by using a roller to obtain the fiber web; the temperature during hot rolling and shaping is 70 ℃, and the pressure of hot rolling and shaping is 0.1 MPa.

Example 2

The lyocell fiber of this example is different from example 1 in that a mixed solvent prepared by uniformly mixing N-methylmorpholine-N-oxide, a cosolvent, a stabilizer and water in a mass ratio of 80:10:5:10 in step 1) is otherwise the same as that of example 1.

Example 3

The lyocell fiber of this example is different from example 2 in that a mixed solvent prepared by uniformly mixing N-methylmorpholine-N-oxide, a cosolvent, a stabilizer and water in a mass ratio of 76:9:3:12 in step 1) is otherwise the same as that of example 2.

Example 4

The lyocell fiber of this example is different from example 3 in that a mixed solvent prepared by uniformly mixing N-methylmorpholine-N-oxide, a cosolvent, a stabilizer, methanol and water in a mass ratio of 76:9:3:3:12 in step 1) is otherwise the same as that of example 3.

Example 5

The lyocell fiber of this example is different from example 4 in that a mixed solvent prepared by uniformly mixing N-methylmorpholine-N-oxide, a cosolvent, a stabilizer, methanol, activated carbon and water in a mass ratio of 76:9:3:3:1:12 in step 1) is otherwise the same as that of example 4.

Example 6

The lyocell fiber of this example is different from example 5 in that N-methylmorpholine-N-oxide, a cosolvent, a stabilizer, methanol, activated carbon, silk fibroin, and water in a mass ratio of 76:9:3:2:2:5.5:12 are uniformly mixed in step 1) to prepare a mixed solvent, and the others are the same as those in example 5.

Example 7

The lyocell fiber of this example is different from example 6 in that the mixed solvent is added to the vacuum dissolution kettle in step 1), then the cellulose raw material is added, and the mixture is stirred for 2 hours at 50 ℃ and a vacuum degree of 0.01MPa to prepare a stock solution, and the others are the same as those in example 6.

Example 8

The lyocell fiber of this example is different from example 7 in that the mixed solvent is added to the vacuum dissolution kettle in step 1), then the cellulose raw material is added, and the mixture is stirred for 2.5 hours at 55 ℃ and a vacuum degree of 0.02MPa to prepare a stock solution, and the others are the same as those in example 7.

Example 9

The lyocell fiber of this example is different from example 8 in that the cosolvent in step 1) is 3- (trifluoromethyl) phenyltrimethylammonium hydroxide, and the rest is the same as in example 8.

Example 10

The lyocell fiber of this example is different from example 9 in that the stabilizer in step 1) is polyoxypropylene polyoxyethylene glycerol ether, and the rest is the same as in example 9.

Example 11

The lyocell fiber of this example is different from example 10 in that the dope is filtered in step 2) and put into a vacuum oven at 80 ℃ to be defoamed for 24 hours, and the rest is the same as that in example 10.

Example 12

The lyocell fiber of this example is different from example 11 in that the raw liquid in step 2) is filtered and put into a vacuum oven at 82 ℃ to be left standing and defoamed for 12 hours, and the rest is the same as that in example 11.

Example 13

The lyocell fiber of this example is different from that of example 12 in that the spinning speed in step 2) is 15m/min and the hole diameter of the spinneret is 15 μm, and the others are the same as those of example 12.

Example 14

The lyocell fiber of this example is different from example 13 in that the coagulation bath used in the coagulation bath in step 3) is obtained by mixing NMMO and water at a mass ratio of 15:75, the temperature of the coagulation bath is 10 ℃, and the rest is the same as that of example 13.

Example 15

The lyocell fiber of this example is different from example 14 in that the coagulation bath used in the coagulation bath in step 3) is obtained by mixing N-methylmorpholine-N-oxide, water, ethylene glycol and glycerol in a mass ratio of 10:80:3:7, the temperature of the coagulation bath is 2 ℃, and the other steps are the same as those in example 14.

Example 16

The lyocell fiber of this example is different from example 15 in that the coagulation liquid used in the coagulation bath in step 3) is obtained by mixing N-methylmorpholine-N-oxide, water, ethylene glycol, and glycerol at a mass ratio of 10:80:4:6, the temperature of the coagulation liquid is 2 ℃, and the other steps are the same as those in example 15.

Example 17

The lyocell fiber of this example is different from example 16 in that the cleaning liquid used in the cleaning in step 4) is obtained by mixing ethanol, methanol and water at a volume ratio of 55:30:15, and the rest is the same as that in example 16.

Example 18

The lyocell fiber of this example is different from example 17 in that the cleaning liquid used in the cleaning in step 4) is obtained by mixing ethanol, methanol and water at a volume ratio of 60:25:15, and the rest is the same as that in example 17.

Example 19

The lyocell fiber of this example is different from example 18 in that the washed silk thread is immersed in water at 85 ℃ for 1 hour in step 4), and then immersed in water at 5 ℃ for 3 hours, taken out, and dried, and the rest is the same as that in example 18.

Example 20

The difference between the method of manufacturing a lyocell fabric mask cloth of this example and example 19 is that the pressures of the five hydroentangling processes in step S1 are 0.8MPa, 6MPa, 10MPa, 12MPa, and 15MPa, respectively, and the other processes are the same as those in example 19.

Example 21

The difference between the method for manufacturing the lyocell fiber mask cloth of this example and example 20 is that the temperature in the hot-roll forming in step S2 is 80 ℃, and the pressure in the hot-roll forming is 0.05MPa, which are otherwise the same as those in example 20.

Example 22

The difference between the manufacturing method of the lyocell fiber mask cloth of this embodiment and embodiment 21 is that, in step S2, the fiber web after being subjected to the hydroentanglement processing in step S1 is dried, then is added into the first soaking solution to be soaked for 5min, then is taken out, is dried at 80 ℃ for 30min, then is put into the second soaking solution to be soaked for 30min, then is taken out to be dried at 70 ℃ for 40min, and then is subjected to hot rolling setting by using a roller, wherein the temperature during the hot rolling setting is 80 ℃, the pressure of the hot rolling setting is 0.05MPa, and the rest is the same as that in embodiment 21.

Comparative example

Comparative example 1

The lyocell fiber of this comparative example is different from example 1 in that a cosolvent and a stabilizer are not added to the mixed solvent in step 1), and the others are the same as those in example 1.

Comparative example 2

The lyocell fiber of this comparative example is different from example 1 in that no cosolvent is added to the mixed solvent in step 1), and the others are the same as those in example 1.

Comparative example 3

The lyocell fiber of this comparative example is different from example 1 in that a stabilizer is not added to the mixed solvent in step 1), and the others are the same as those in example 1.

Comparative example 4

The lyocell fiber of this comparative example is different from example 1 in that the dope is prepared by adding the mixed solvent and the cellulose raw material to the vacuum dissolution vessel in step 1) and then stirring at 120 ℃ and a vacuum degree of 0.05MPa for 3 hours, and the other steps are the same as those of example 1.

Performance test

The lyocell fibers and lyocell fiber mask cloths of examples 1 to 22 and comparative examples 1 to 4 were taken and tested as follows:

(1) mechanical Property test

The strength of the lyocell fibers was measured according to the test method in GB/T14337-.

According to GB/T24218.3-2010, test method for textile nonwovens part 3: the determination method in determination of breaking strength and breaking elongation (bar sample method) tests the tensile strength and breaking elongation of a lyocell fiber mask cloth sample, 5 samples are respectively taken from the sample along the machine output direction (longitudinal direction) and the cloth width direction (transverse direction), the sample is more than 100mm away from the cloth edge, the sample width is 50mm, the length meets the clamping distance of 200mm, and after the test is finished, the average value of the tensile strength and the average value of the breaking elongation of the 5 longitudinal samples are calculated. The test results are shown in the following table.

TABLE 1 comparison of mechanical Properties of Lyocell fibers and mask cloths in examples 1-22 and comparative examples 1-4

As can be seen from example 1, comparative example 1, and table 1, the dissolution efficiency of cellulose was high after adding the cosolvent and the stabilizer, the components in the obtained stock solution were more uniformly dispersed, the strength of the lyocell fiber was higher, and the change in elongation at break was not significant.

As can be seen from example 1, comparative example 2, comparative example 3 and table 1, the strength of the finally produced lyocell fiber was relatively more affected by the co-solvent, and the strength of the fiber was not significantly affected by the stabilizer.

According to example 1, comparative example 4 and table 1, the temperature at which the cellulose is dissolved has a great influence on the strength of the fiber, and the lyocell fiber finally prepared by the present application using a lower temperature for dissolution has a very good mechanical property.

(2) Air permeability test

According to GB/T24218.15-2018, part 15 of the test method of textile nonwovens: the air permeability of the lyocell fiber mask cloth sample is measured by the measuring method in the determination of air permeability, the sample is 5 samples obtained by cutting randomly selected 5 areas, the size of the sample is 100 x 100mm, the pressure difference of the air flow of a vacuum pump on the upper surface and the lower surface of the sample is 200Pa, and the circular measuring area of a measuring head is 20cm²And averaging after the test is finished.

(3) Liquid absorption test

According to GB/T24218.6-2010, test method for textile nonwovens part 6: the measurement method in "measurement of absorbency" measures the liquid absorption capacity of lyocell fiber mask cloth samples, which are 5 samples cut from 5 randomly selected regions, the sample size being 100 × 100mm, and the average value was taken after the measurement was completed.

The test results are shown in the following table.

TABLE 2 comparison of air and liquid permeability of the face masks of examples 1-22 and comparative examples 1-4

As is clear from example 1, comparative example 1 and table 2, the air permeability and liquid absorption of the lyocell fabric mask cloth of the present application were improved to some extent.

As can be seen from example 1, comparative example 2, comparative example 3 and table 2, the lyocell fiber mask cloth of the present application has improved air permeability and liquid absorption, but relatively speaking, the cosolvent has a greater influence on the air permeability and liquid absorption of the mask cloth.

As is clear from example 1, comparative example 4 and table 2, the lyocell fabric mask cloth of the present application has significantly improved air permeability and liquid absorbency.

In summary, the lyocell fibers prepared by the method have high strength and good mechanical property, and the lyocell fiber mask cloth prepared by the lyocell fibers has good mechanical property, good air permeability and good moisture retention.

Claims

1. Lyocell fibre, characterized in that it is obtained by a process comprising the steps of:

2. Lyocell fiber according to claim 1, wherein the step of uniformly mixing the cellulose raw material with the mixed solvent in step 1) is carried out by stirring under a vacuum of 0.01 to 0.05MPa for 2 to 3 hours.

3. The lyocell fiber according to claim 1, wherein the raw material for preparing the mixed solvent in step 1) further comprises 2 to 3 parts by weight of methanol.

4. The lyocell fiber according to claim 3, wherein the raw material for preparing the mixed solvent in step 1) further comprises 5 to 6 parts by weight of silk fibroin.

5. Lyocell fiber according to claim 1, wherein the filtration in step 2) is followed by a defoaming treatment, wherein the defoaming treatment comprises allowing the filtered dope to stand at 80-85 ℃ for 12-24 hours.

6. The lyocell fiber according to claim 1, wherein the bath liquid used in the coagulation bath in step 2) is prepared by mixing the following raw materials in parts by weight: 10-20 parts of N-methylmorpholine-N-oxide and 70-80 parts of water.

7. Lyocell fiber according to claim 6, wherein the bath preparation raw materials of the coagulation bath further comprise ethylene glycol and glycerol, and the mass ratio of ethylene glycol, glycerol and N-methylmorpholine-N-oxide is 3-4:6-7: 10-20.

8. Lyocell fiber according to claim 7, characterized in that in step 2), washing is carried out after the coagulation bath forming, and the washing liquid used in washing is obtained by mixing fatty alcohol and water in a volume ratio of 80-85: 15-20; the aliphatic alcohol is at least one of methanol and ethanol.

9. A lyocell fiber mask cloth, produced from the lyocell fiber according to claim 1.

10. The method for manufacturing the lyocell fiber mask cloth is characterized by comprising the following steps of:

s1, carding and laying the lyocell fibers as claimed in claim 1 into a fiber web, and then carrying out spunlace treatment, wherein the spunlace treatment comprises five spunlace treatments, and the spunlace pressure of the five spunlace treatments is 0.7-0.9MPa, 5-6MPa, 9-10MPa, 11-13MPa and 15-16MPa respectively;