Preparation method of environment-friendly plant fiber for tableware and product thereof

Abstract

The application relates to the technical field of plant fiber processing, in particular to a preparation method of environment-friendly plant fiber for tableware and a product thereof, S1, bamboo is collected, the bamboo is smashed into pieces, the smashed bamboo is soaked in an alkali solution with a temperature of 40-50 DEG C, the soaked bamboo is taken out, ground and bamboo powder is obtained; S2, the dried bamboo is soaked in an enzymolysis solution, the soaking time is 6-8 h, the soaking temperature is 50-60 DEG C, filtration is carried out, and the filter residue is taken; S3, the filter residue is soaked in an alkali solution, the soaking time is 2-3 h, the soaking temperature is 70-80 DEG C, filtration is carried out, and the filter residue is taken; S4, the filter residue is boiled in a salt solution, the boiling time is 1-2 h, the boiling temperature is 100-110 DEG C, filtration is carried out, and the filter residue is taken; S5, the filter residue is washed with water, dried, and the primary product is obtained; S6, the primary product and wax are mixed at 70-80 DEG C, the wax is used in an amount of 4-8% of the weight of the primary product, and the semi-finished product is obtained; and S7, the semi-finished product, polylactic acid, hydroxyl silane coupling agent, glycerol, mica powder, castor oil and chitosan are mixed and subjected to melt extrusion, and the environment-friendly plant fiber for tableware is obtained.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of plant fiber processing, and more particularly to an environmentally-friendly plant fiber preparation method for tableware and a product thereof. BACKGROUND

[0002] The recyclable and easily degradable plant fiber can replace the foam and plastic cushion packaging material, and is an ideal choice for replacing traditional plastic products to eliminate white pollution.

[0003] Common plant fibers mainly include bamboo fibers, wood fibers, sugarcane fibers and straw fibers. The bamboo fiber has high strength and toughness, so that the fast food box and the packaging bag can withstand a certain weight and pressure and are not easy to be damaged. In addition, the bamboo fiber has good wear resistance and can resist wear and tear in daily use, so it is an ideal material for preparing fast food packaging boxes and packaging bags. However, if the fast food packaging boxes and packaging bags prepared mainly from bamboo fibers are placed in a humid environment, they are easy to absorb water, resulting in deformation or damage. The main reason is that the fiber structure of the bamboo fiber has a certain hygroscopicity and is easy to absorb water in the air. In order to improve the waterproofness of the fast food packaging boxes and packaging bags prepared mainly from bamboo fibers, a waterproof coating is usually coated on the surface thereof. However, the waterproof coating is mainly formed by non-degradable high molecular polymers, such as polyurethane waterproof coating and polyvinyl chloride waterproof coating. These are non-degradable materials and will affect the degradation of the corresponding products. SUMMARY

[0004] In order to improve the moisture-proof performance of the bamboo fiber and ensure that the corresponding product can be completely degraded, the application provides an environmentally-friendly plant fiber preparation method for tableware and a product thereof.

[0005] In the first aspect, the application provides an environmentally-friendly plant fiber preparation method for tableware, which adopts the following technical scheme: an environmentally-friendly plant fiber preparation method for tableware, comprising the following preparation steps:

[0006] S1, collecting bamboo, crushing the bamboo into pieces, soaking the crushed bamboo in an alkali solution with a temperature of 40-50 DEG C, taking out, grinding, and obtaining ground bamboo powder;

[0007] S2, soaking the dried bamboo in an enzymatic solution, soaking for 6-8 hours, soaking at a temperature of 50-60 DEG C, filtering, and taking the filter residue;

[0008] S3, soaking the filter residue in an alkali solution, soaking for 2-3 hours, soaking at a temperature of 70-80 DEG C, filtering, and taking the filter residue;

[0009] S4, decocting the filter residue in a salt solution, the decoction time is 1-2h, the decoction temperature is 100-110℃, filtering, taking the filter residue, the salt solution is obtained by mixing sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water;

[0010] S5, washing the filter residue with water, drying, to obtain the primary product;

[0011] S6, mixing the primary product and wax at 70-80℃, the amount of wax is 4-8% of the weight of the primary product, to obtain the semi-finished product;

[0012] S7, mixing the semi-finished product, polylactic acid, hydroxyl silane coupling agent, glycerol, mica powder, castor oil and chitosan, and then melting and extruding to obtain the environmentally friendly plant fiber for tableware.

[0013] By adopting the above technical scheme, the environmentally friendly plant fiber for tableware prepared has good waterproof performance, so that the fast food packaging box and packaging bag mainly made of bamboo fiber are not easy to absorb moisture in a humid environment, avoiding the problem of deformation or damage. At the same time, by adding polylactic acid, hydroxyl silane coupling agent, glycerol, mica powder, castor oil and chitosan to participate in the preparation of the fiber, the strength and deformation resistance of the environmentally friendly plant fiber for tableware are further improved, and these raw materials are all degradable materials, which ensures that the environmentally friendly plant fiber for tableware can be completely degraded after being discarded, without causing pollution to the environment. This environmentally friendly plant fiber can be directly prepared into fast food packaging boxes or packaging bags without adding any auxiliary materials.

[0014] In step S1, the bamboo is crushed to destroy its original fiber structure, making the fibers easier to disperse and extract. At the same time, soaking in warm water can soften the bamboo, further promoting the separation of the fibers. By controlling the soaking and drying conditions, the moisture content of the bamboo can be adjusted. The appropriate moisture content helps the uniform dispersion and processing of the fibers in the subsequent steps. Regular water spraying helps the fibers to interweave and combine with each other, providing a good foundation for the subsequent fiber extraction.

[0015] In step S2, the enzymatic solution can destroy part of the lignin and hemicellulose in the bamboo fibers, making the fiber structure more loose, which is conducive to the penetration and combination of other substances in the subsequent processing. At the same time, enzymatic treatment can also remove part of the impurities in the fibers, improving the purity of the fibers.

[0016] In step S3, the alkali solution can further remove impurities in the bamboo fibers and make the surface of the fibers more rough, increasing the bonding force with other materials. At the same time, alkali treatment also helps to improve the moisture absorption and dimensional stability of the bamboo fibers.

[0017] The ions in the salt solution in step S4 can react with the functional groups on the surface of the bamboo fibers to form chemical bonds, thereby enhancing the binding force between the fibers. At the same time, the boiling process of the salt solution also helps to further remove water and volatile substances from the fibers, improving the stability of the fibers.

[0018] In step S6, by mixing the primary product and wax, the wax can form a thin waterproof layer covering the surface of the bamboo fibers, preventing water penetration. At the same time, the waxy material also has a certain lubricating effect, which helps the smooth progress of the subsequent melt extrusion process.

[0019] In step S7, polylactic acid can be closely combined with bamboo fibers to form a continuous network structure, thereby improving the strength and toughness of the product. Hydroxyl silane coupling agent is a compound with double functional groups, one end can react with the hydroxyl group on the surface of the bamboo fiber, the other end can react with the polymer such as polylactic acid. Therefore, it can play the role of a bridge to tightly connect bamboo fibers and polymers together, enhancing the bonding force of the interface. Glycerol can increase the flexibility and plasticity of the product; mica powder as an inorganic filler can enhance the mechanical strength of the product, while improving the heat resistance of bamboo fibers; castor oil can improve the processing performance and lubricity of the product. Chitosan has certain strength and toughness. In the process of fiber preparation, the addition of chitosan can further enhance the physical properties of the fiber, such as strength, toughness, etc., which helps to improve the durability and service life of the product.

[0020] Preferably, the enzymatic solution is obtained by mixing xylanase, lignin-degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent according to the weight ratio of (0.2-0.5):(0.1-0.3):(0.2-0.5):(0.05-0.1):(0.05-0.15):10.

[0021] By using the above technical solution, the types and amounts of enzymes in the enzymatic solution are optimized, which can efficiently degrade xylan, lignin and hemicellulose components in bamboo fibers, making the bamboo fiber structure more loose, which is conducive to the penetration and combination of other substances in the subsequent processing steps. And the bamboo fibers treated by the above enzymatic solution maintain the original high strength and toughness, while having good wear resistance and tear resistance. At the same time, the roughness and activity of the bamboo fiber surface are increased, which makes it easier to combine with other materials (such as polylactic acid, glycerol, etc.), forming a tight network structure, improving the strength and toughness of the product.

[0022] Preferably, the weight ratio of sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water is (0.2-0.4):(1-2):(0.5-1):(0.5-0.8):(1-1.5):12.

[0023] By adopting the above technical scheme, the use amounts of sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water are optimized, and the stability and strength of the fiber are further increased. The sodium thiosulfate and the sodium chloride in the ratio can adjust the ionic strength and the pH value of the solution, which helps to enhance the stability of the fiber in the preparation process and prevent the fiber from being damaged due to chemical changes. The synergistic effect of the potassium phosphate, the potassium chloride and the potassium sulfate can further consolidate the fiber structure and improve the strength and toughness of the fiber, so that the fiber is more durable.

[0024] Preferably, the concentration of sodium hydroxide in the alkali solution is 10-20 g / L, the concentration of calcium hydroxide is 5-10 g / L, and the concentration of sodium bicarbonate is 15-20 g / L.

[0025] By adopting the above technical scheme, the components and concentrations in the alkali solution are optimized, and the strength and toughness of the bamboo fiber are further improved while ensuring that the degradation performance of the bamboo fiber is not affected.

[0026] Preferably, the weight ratio of the semi-finished product, the polylactic acid, the hydroxyl silane coupling agent, the glycerol, the mica powder, the castor oil and the chitosan is 20:(3-6)(0.5-1):(1-2):(4-6):(2-3):(2-4).

[0027] By adopting the above technical scheme, the weights of various raw materials are optimized, and the overall strength, waterproof and moisture resistance, tear resistance and toughness of the environment-friendly plant fiber are further enhanced, so that it can withstand greater weight and pressure and is not easy to break. By adding an appropriate amount of polylactic acid, the overall strength and toughness of the plant fiber are increased, and at the same time, the plant fiber can be directly prepared into fast food packaging boxes and packaging bags; an appropriate amount of chitosan and mica powder can improve the wear resistance and tear resistance of the plant fiber, so that it can resist wear and tear in daily use and prolong the service life of the product.

[0028] Preferably, the mica powder is a modified mica powder, which is prepared by the following method:

[0029] 1) Mix the amino silane coupling agent and the solvent to obtain a mixed solution;

[0030] 2) Mix the mica powder and hydrogen peroxide, heat and stir to react, and then obtain hydroxylated mica powder;

[0031] 3) Blend the mixed solution and the hydroxylated mica powder, ultrasonically heat at 70-90℃ for 1-2h, filter, ethanol elute, filter, take the filter residue, and dry to obtain the modified mica powder.

[0032] Preferably, the weights of the raw materials used to prepare the modified mica powder are as follows:

[0033] Amino silane coupling agent 0.2-0.5 parts

[0034] Solvent 5-10 parts

[0035] Mica powder 2-3 parts

[0036] Hydrogen peroxide 4-6 parts.

[0037] By adopting the above technical scheme, the dispersibility of the mica powder is further improved, and the poor interfacial compatibility between the plant fiber mica powder and the high molecular material such as polylactic acid is improved. The poor interfacial compatibility easily leads to that the interface is not tightly combined, and defects and cracks are easily generated in the fiber, thereby affecting the overall performance of the plant fiber, such as strength and toughness. The functional groups of the amino silane coupling agent are introduced on the surface of the modified mica powder. These functional groups can form chemical bonds or hydrogen bonds with polylactic acid, glycerol and other components, thereby enhancing the interfacial bonding force, helping to improve the overall strength and toughness of the plant fiber, and reducing the generation of internal defects and cracks.

[0038] Preferably, the amino silane coupling agent includes at least one of 3-aminopropyl trimethyl silane, 3-aminopropyl triethoxysilane, N-(aminoethyl)-aminopropyl trimethoxysilane, N-(aminoethyl)-aminopropyl methyl dimethoxysilane, N-(aminoethyl)-aminopropyl triethoxysilane and diethylenetriamine propyl trimethoxysilane.

[0039] By adopting the above technical scheme, the bonding force between the mica powder and polylactic acid, glycerol, castor oil and the like is further improved, and the overall performance of the plant fiber is further improved.

[0040] Preferably, the wax includes at least one of beeswax, palm wax or pineapple wax.

[0041] By adopting the above technical scheme, the waterproof performance of the bamboo fiber is further improved, and the degradation performance of the bamboo fiber is not affected.

[0042] In a second aspect, the present application provides an environmentally friendly plant fiber for tableware, which adopts the following technical scheme:

[0043] An environmentally friendly plant fiber for tableware, the plant fiber is used for preparing tableware.

[0044] By adopting the above technical scheme, the lightness, waterproof and moisture-proof performance of the tableware can be improved, and the tableware can be completely degraded.

[0045] In summary, the present application has the following beneficial effects:

[0046] 1、The application optimizes the fiber structure of bamboo fiber through crushing, soaking, air-drying and multiple water spraying treatments, enhances the interweaving degree and overall strength of the internal fibers, and further removes part of lignin and hemicellulose through enzymatic hydrolysis treatment, so that the fibers are more pure, the moisture absorption and biodegradability of the fibers are improved, the impurities on the surface of the fibers are further removed through alkali solution treatment, the wettability and processability of the fibers are improved, the fibers are further stabilized and shaped through salt solution boiling treatment, the toughness and strength of the fibers are improved, wax is added to the initial product to form a waterproof barrier, which effectively reduces the absorption of water by the bamboo fiber, thereby improving the waterproof performance of the fiber, and finally the action of polylactic acid, glycerol, mica powder, castor oil and chitosan not only enhances the strength and toughness of the fiber, but also ensures the complete degradability of the product. DETAILED DESCRIPTION

[0047] EMBODIMENT

[0048] The polylactic acid is purchased from Dongguan Hongyi Plastic Co., Ltd., the brand is NatureWorks of the United States, and the model is 4032D.

[0049] EMBODIMENT 1

[0050] An environmentally friendly plant fiber for tableware is prepared by the following method:

[0051] S1, 5000g of bamboo is collected, the bamboo is crushed, and the crushed bamboo is soaked in a sodium hydroxide solution (mass fraction of 10%) at a temperature of 40℃, taken out, ground, and bamboo powder is obtained;

[0052] S2, the dried bamboo is soaked in an enzymatic hydrolysis solution, the soaking time is 6h, the soaking temperature is 50℃, filtration is performed, the filter residue is taken, and the enzymatic hydrolysis solution is obtained by mixing xylanase, lignin-degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent (water) according to a weight ratio of 0.2:0.1:0.2:0.05:0.05:10;

[0053] S3, the filter residue is soaked in an alkali solution, the soaking time is 2h, the soaking temperature is 70℃, filtration is performed, the filter residue is taken, and the concentration of sodium hydroxide in the alkali solution is 10g / L, the concentration of calcium hydroxide is 5g / L, and the concentration of sodium bicarbonate is 15g / L;

[0054] S4, the filter residue is boiled in a salt solution, the boiling time is 1-2h, the boiling temperature is 100℃, filtration is performed, the filter residue is taken, and the salt solution is obtained by mixing sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water according to a weight ratio of 0.2:1:0.5:0.5:1:12;

[0055] S5, the filter residue is washed with water and dried to obtain an initial product;

[0056] S6, mix the crude product 1000g and wax at 70℃, the amount of wax is 40g, to obtain a semi-finished product;

[0057] S7, mix the semi-finished product 1000g, polylactic acid 150g, hydroxyl silane coupling agent 25g (3-hydroxypropyl trimethoxysilane), glycerol 50g, mica powder 200g, castor oil 100g and chitosan 100g, the weight ratio of the semi-finished product, polylactic acid, hydroxyl silane coupling agent, glycerol, mica powder, castor oil and chitosan is 20:3:0.5:1:4:2:2, melt extrusion to obtain an environmentally friendly plant fiber for tableware.

[0058] Example 2-3 differs from example 1 in that the types and amounts of raw materials for preparing environmentally friendly plant fiber for tableware and experimental parameters are different, and the specific differences are shown in Table 1:

[0059] Table 1 Types and amounts of raw materials and experimental parameters of environmentally friendly plant fiber for tableware in examples 1-3

[0060]

[0061]

[0062] Example 4

[0063] An environmentally friendly plant fiber for tableware, the difference between this embodiment and example 1 is that the enzymatic solution is obtained by mixing xylanase, lignin-degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent according to the weight ratio of 0.2:0.2:0.2:0.2:0.2:10.

[0064] Example 5

[0065] An environmentally friendly plant fiber for tableware, the difference between this embodiment and example 1 is that the enzymatic solution is obtained by mixing xylanase, lignin-degrading enzyme, glyoxal oxidase and solvent according to the weight ratio of 0.2-:0.1:0.05-:10.

[0066] Example 6

[0067] An environmentally friendly plant fiber for tableware, the difference between this embodiment and example 1 is that sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water are mixed according to the weight ratio of 0.5:0.5:0.5:0.5:0.5:12.

[0068] Example 7

[0069] An environmentally friendly plant fiber for tableware, the difference between this embodiment and example 1 is that the alkali solution is sodium hydroxide solution, the concentration is 10g / L.

[0070] Example 8

[0071] An environmentally friendly plant fiber for tableware, different from Example 1 in that the alkali solution is a calcium hydroxide solution with a concentration of 5 g / L.

[0072] Example 9

[0073] An environmentally friendly plant fiber for tableware, different from Example 1 in that the mica powder is a modified mica powder prepared by the following method:

[0074] 1) Mix 20 g of amino silane coupling agent (3-aminopropyltrimethylsilane) and 500 g of solvent (ethanol) to obtain a mixed solution;

[0075] 2) Mix 200 g of mica powder and 400 g of hydrogen peroxide, and after heating and stirring to react, obtain hydroxylated mica powder;

[0076] 3) Blend the mixed solution and the hydroxylated mica powder, ultrasonically heat at 70°C for 1 h, filter, ethanol rinse, filter, take the filter residue, and dry to obtain the modified mica powder.

[0077] Example 10

[0078] An environmentally friendly plant fiber for tableware, different from Example 1 in that the mica powder is a modified mica powder prepared by the following method:

[0079] 1) Mix 50 g of amino silane coupling agent (N-(aminoethyl)-aminopropyltrimethoxysilane) and 100 g of solvent (ethanol) to obtain a mixed solution;

[0080] 2) Mix 300 g of mica powder and 600 g of hydrogen peroxide, and after heating and stirring to react, obtain hydroxylated mica powder;

[0081] 3) Blend the mixed solution and the hydroxylated mica powder, ultrasonically heat at 90°C for 2 h, filter, ethanol rinse, filter, take the filter residue, and dry to obtain the modified mica powder.

[0082] Comparative Example

[0083] Comparative Example 1

[0084] An environmentally friendly plant fiber for tableware, different from Example 1 in that a 10% mass fraction hydrochloric acid solution is used instead of a sodium hydroxide solution in step S1.

[0085] Comparative Example 2

[0086] An environmentally friendly plant fiber for tableware, different from Example 1 in that the ground bamboo powder is first processed according to step S3, and then processed according to step S2.

[0087] Comparative Example 3

[0088] An environmentally friendly plant fiber for tableware, different from Example 1 in that pure water is used instead of a salt solution in step S4.

[0089] Comparative Example 4

[0090] An environmentally friendly plant fiber for tableware, different from Example 1 in that no beeswax is added in step S6.

[0091] Comparative Example 5

[0092] An environmentally friendly plant fiber for tableware, different from Example 1 in that PET is used instead of polylactic acid in step S7.

[0093] The PET is purchased from Dongguan Julong Plastic Raw Material Co., Ltd., brand: U.S. Basic Innovative Plastics (Sabic), grade: 830F.

[0094] Comparative Example 6

[0095] An environmentally friendly plant fiber for tableware, different from Example 1 in that hydroxymethyl cellulose is used instead of chitosan in step S7.

[0096] Detection method / test method

[0097] Degradation performance test: The test is performed by burying a 100 g (M1) sample of the dried to constant weight environmentally friendly plant fiber for tableware in a container filled with soil. After 6 months of degradation, the soil-buried sample is removed, cleaned, and dried to constant weight (M2). The degradation rate is calculated according to the formula: degradation rate = (M1-M2) / M1 x 100%.

[0098] Waterproof performance test: The environmentally friendly plant fiber for tableware obtained in Examples 1-10 and Comparative Examples 1-5 is hot-pressed into a packaging bag using a film press at a temperature of 180°C and a pressure of 200t. Hot water at 90°C is added to the packaging bag, which is sealed and placed in an environment at 90°C for 24 hours. The leakage of the packaging bag is observed. The hot-pressing temperature in Comparative Example 5 is 270°C.

[0099] Moisture resistance test: 10 g of the environmentally friendly plant fiber for tableware obtained in Examples 1-10 and Comparative Examples 1-5 is soaked in pure water for 24 hours, removed, surface water is wiped off, and then weighed again to record the weight gain in grams.

[0100] Tensile strength: tested according to the method specified in GB / T 1040.1-2006.

[0101] Izod impact strength: tested according to the method specified in GB / T 1843-2008. The experimental data are shown in Table 2.

[0102] Table 2 Experimental data of Examples 1-10 and Comparative Examples 1-5

[0103]

[0104]

[0105] Comparing Example 1 with Comparative Examples 1-4, the degradation rate of Comparative Examples 1-4 is slightly lower than that of Example 1; water leakage occurs in Comparative Examples 2 and 4, the weight increase of Comparative Examples 1-4 is also higher than that of Example 1, and the tensile strength and Izod impact strength of Comparative Examples 1-3 are lower than those of Example 1, indicating that the environmentally friendly plant fiber for tableware prepared by the preparation process in the application has good degradation, waterproof and moisture-proof properties and strength.

[0106] Comparing Example 1 with Comparative Examples 5-6, the degradation rate of Comparative Example 5 is greatly reduced, and the degradation rate of Comparative Example 6 is lower than that of Example 1; the weight increase of Comparative Examples 5-6 is also higher than that of Example 1, indicating that by using chitosan, polylactic acid and other raw materials together in step 7, the environmentally friendly plant fiber for tableware can further improve the degradation and waterproof and moisture-proof properties.

[0107] Comparing Example 1 with Examples 4-5, the degradation rate of Examples 4-5 is slightly lower than that of Example 1; the weight increase of Examples 4-5 is also higher than that of Example 1, and the tensile strength and Izod impact strength of Examples 4-5 are lower than those of Example 1, indicating that by adjusting the composition and amount of the enzymatic solution, the environmentally friendly plant fiber for tableware can further improve the degradation, waterproof and moisture-proof properties and strength.

[0108] Comparing Example 1 with Example 6, the weight increase of Example 6 is also higher than that of Example 1, and the tensile strength and Izod impact strength of Example 6 are lower than those of Example 1, indicating that by adjusting the composition and amount of the salt solution, the environmentally friendly plant fiber for tableware can further improve the degradation, waterproof and moisture-proof properties and strength.

[0109] Comparing Example 1 with Examples 7-8, the weight increase of Examples 7-8 is also higher than that of Example 1, and the tensile strength and Izod impact strength of Examples 7-8 are lower than those of Example 1, indicating that by adjusting the composition and amount of the alkali solution, the environmentally friendly plant fiber for tableware can further improve the waterproof and moisture-proof properties and strength.

[0110] Compared with example 1 and examples 7-8, the degradation rates of examples 9-10 are higher than that of example 1; the weight increase amounts of examples 9-10 are also lower than that of example 1, the tensile strength and the cantilever beam impact strength of examples 9-10 are lower than those of example 1, which indicates that the modified mica powder prepared by using the application can further improve the good degradability, waterproof and moisture-proof performance and strength of the environmentally friendly plant fiber for tableware.

[0111] The specific embodiments are only an explanation of the application, which is not a limitation of the application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the specification, but as long as it is within the scope of the claims of the application, it is protected by the patent law.

Claims

1. An environmentally friendly plant fiber manufacturing method for tableware, characterized by, The preparation method comprises the following steps: S1, collecting bamboo, crushing the bamboo into pieces, soaking the crushed bamboo in an alkali solution at a temperature of 40-50℃, taking out, grinding, and obtaining ground bamboo powder; S2, soaking the dried bamboo in an enzymatic solution, soaking for 6-8h, soaking temperature is 50-60℃, filtering, taking the filter residue; S3, soaking the filter residue in an alkali solution, soaking time is 2-3h, soaking temperature is 70-80℃, filtering, taking the filter residue; S4, placing the filter residue in a salt solution for boiling, boiling time is 1-2h, boiling temperature is 100-110℃, filtering, taking the filter residue, the salt solution is obtained by mixing sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water; S5, washing the filter residue with water, drying, and obtaining the primary product; S6, mixing the primary product and wax at 70-80℃, the amount of wax is 4-8% of the weight of the primary product, and obtaining the semi-finished product; S7, mixing the semi-finished product, polylactic acid, hydroxyl silane coupling agent, glycerol, mica powder, castor oil and chitosan, and obtaining the environmentally friendly plant fiber for tableware through melt extrusion. The enzymatic solution is obtained by mixing xylanase, lignin-degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent according to the weight ratio of (0.2-0.5):(0.1-0.3):(0.2-0.5):(0.05-0.1):(0.05-0.15):

10. The weight ratio of sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water is (0.2-0.4):(1-2):(0.5-1):(0.5-0.8):(1-1.5):12; the weight ratio of the semi-finished product, the polylactic acid, the hydroxyl silane coupling agent, the glycerol, the mica powder, the castor oil and the chitosan is 20:(3-6)(0.5-1):(1-2):(4-6):(2-3):(2-4).

2. The method for preparing an environmentally friendly plant fiber tableware according to claim 1, characterized in that: The concentration of sodium hydroxide in the alkali solution is 10-20g / L, the concentration of calcium hydroxide is 5-10g / L, and the concentration of sodium bicarbonate is 15-20g / L.

3. The method according to claim 1, wherein the plant fiber is selected from the group consisting of bamboo, hemp, jute, ramie, sisal, flax, and cotton. The mica powder is modified mica powder, which is prepared by the following method: 1) mixing amino silane coupling agent and solvent to obtain a mixed solution; 2) mixing mica powder and hydrogen peroxide, and obtaining hydroxylated mica powder after heating and stirring reaction; 3) blending the mixed solution and the hydroxylated mica powder, ultrasonic heating at 70-90℃ for 1-2h, filtering, ethanol elution, filtering, taking the filter residue, and drying to obtain the modified mica powder.

4. The method for preparing environmentally friendly plant fiber for tableware according to claim 3, characterized in that, The weight parts of raw materials used to prepare the modified mica powder are as follows: Amino silane coupling agent 0.2-0.5 parts Solvent 5-10 parts Mica powder 2-3 parts Hydrogen peroxide 4-6 parts.

5. The method for preparing environmentally friendly plant fiber for tableware according to claim 1, characterized in that: The amino silane coupling agent includes at least one of 3-aminopropyltrimethylsilane, 3-aminopropyltriethoxysilane, N-(aminoethyl)-aminopropyltrimethoxysilane, N-(aminoethyl)-aminopropylmethyldimethoxysilane, N-(aminoethyl)-aminopropyltriethoxysilane and diethylenetriaminepropyltrimethoxysilane.

6. The method for preparing an environmentally friendly plant fiber tableware according to claim 1, characterized in that: The wax includes at least one of beeswax, palm wax or pineapple wax.

7. A plant fiber prepared according to the method of any one of claims 1 to 6, characterized in that: The plant fibers are used for the preparation of tableware. The plant fibers are used for the preparation of tableware. The plant

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