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

Abstract

The invention relates to the technical field of plant fiber processing, in particular to a preparation method of environment-friendly plant fibers for tableware and a product thereof, the preparation method comprises the following steps: S1, collecting bamboos, mashing the bamboos into sheets, soaking the mashed bamboos in alkali liquor with the temperature of 40-50 DEG C, taking out and grinding to obtain ground bamboo powder; s2, the air-dried bamboos are soaked in an enzymolysis solution for 6-8 h at the soaking temperature of 50-60 DEG C, filtering is conducted, and filter residues are taken; s3, the filter residues are soaked in an alkali solution for 2-3 h at the soaking temperature of 70-80 DEG C, filtering is conducted, and filter residues are taken; s4, the filter residues are placed in a salt solution to be boiled, the boiling time is 1-2 h, the boiling temperature is 100-110 DEG C, filtering is conducted, and filter residues are taken; s5, cleaning the filter residues with water, and drying to obtain a primary product; s6, the primary product and wax are mixed at the temperature of 70-80 DEG C, the use amount of the wax is 4-8% of the weight of the primary product, and a semi-finished product is obtained; and S7, mixing the semi-finished product, polylactic acid, a hydroxyl silane coupling agent, glycerol, mica powder, castor oil and chitosan, and carrying out melt extrusion to obtain the environment-friendly plant fiber for tableware.

Description

Technical Field

[0001] The present application relates to the technical field of plant fiber processing, and more specifically, to a method for preparing environmentally friendly plant fibers for tableware and a product thereof. Background Art

[0002] my country has a large population, and the demand for plastic fast food packaging boxes and plastic packaging bags is very large. These plastic products exist in the natural environment for a long time, which will destroy the soil structure, affect plant growth, pollute groundwater and oceans, and pose a serious threat to the ecological environment. With the implementation of plastic restriction policies at home and abroad, the theme of sustainability has become a new trend in packaging upgrades and consumption upgrades.

[0003] With the implementation of the "plastic restriction policy" and the reduction of foreign waste quotas, as the demand for packaging boxes and bags in my country grows rapidly, a large gap in plant fiber has been created. Recyclable and easily degradable plant fibers can replace foam and plastic cushioning packaging materials, and are an ideal choice to replace traditional plastic products and eliminate white pollution.

[0004] Commonly used plant fibers are mainly bamboo fiber, wood fiber, sugarcane fiber and straw fiber. Among them, bamboo fiber has high strength and toughness, so that fast food boxes and packaging bags can withstand a certain weight and pressure, and are not easy to break. In addition, bamboo fiber has good wear resistance and can resist wear and tear in daily use. It is an ideal material for preparing fast food packaging boxes and packaging bags. However, if fast food packaging boxes and packaging bags prepared mainly with bamboo fiber are easy to absorb moisture in a humid environment, resulting in deformation or damage, the main reason is that the fiber structure of bamboo fiber makes it have a certain hygroscopicity and easily absorbs moisture in the air. In order to improve the waterproofness of fast food packaging boxes and packaging bags prepared mainly with bamboo fiber, a layer of waterproof coating is usually applied on the surface, but the waterproof coating is mainly formed by non-degradable high molecular polymers, such as polyurethane waterproof coating, polyvinyl chloride waterproof coating, etc., which are difficult to degrade materials and will affect the degradation of corresponding products. Summary of the invention

[0005] In order to improve the moisture-proof performance of bamboo fiber and ensure that the corresponding products can be completely degraded, the present application provides a method for preparing environmentally friendly plant fiber for tableware and its products.

[0006] In the first aspect, the present application provides a method for preparing environmentally friendly plant fibers for tableware, which adopts the following technical scheme: A method for preparing environmentally friendly plant fibers for tableware, comprising the following preparation steps: S1, collecting bamboo, crushing the bamboo into flakes, soaking the crushed bamboo in an alkaline solution at a temperature of 40-50° C., taking out, grinding, and obtaining ground bamboo powder; S2, soaking the dried bamboo in the enzymatic hydrolysis solution for 6-8 hours at a temperature of 50-60°C, filtering and taking the filter residue; S3, soak the filter residue in an alkaline solution for 2-3 hours at a temperature of 70-80°C, filter and take the filter residue; S4, boiling the filter residue in a salt solution for 1-2 hours at a temperature of 100-110° C., filtering, and taking the filter residue, wherein 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, and drying it to obtain a primary product; S6, mixing the primary product and wax at 70-80° C., wherein the amount of the wax is 4-8% by weight of the primary product, to obtain a semi-finished product; S7, mixing the semi-finished product, polylactic acid, hydroxy silane coupling agent, glycerin, mica powder, castor oil and chitosan, and melt-extruding to obtain environmentally friendly plant fibers for tableware.

[0007] By adopting the above technical solution, the environmentally friendly plant fiber for tableware prepared by the method has good waterproof performance, so that fast food packaging boxes and packaging bags 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, hydroxy silane coupling agent, glycerol, mica powder, castor oil and chitosan to participate in the preparation of fibers, the strength and deformation resistance of the environmentally friendly plant fiber for tableware are further improved, and these raw materials are all degradable materials, ensuring that the environmentally friendly plant fiber for tableware can be completely degraded after being discarded and will not cause pollution to the environment. This environmentally friendly plant fiber can be directly used to prepare fast food packaging boxes or packaging bags without adding any auxiliary materials.

[0008] In step S1, crushing the bamboo can 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 and further promote the separation of fibers. By controlling the conditions of soaking and air drying, the water content of the bamboo can be adjusted. The appropriate water 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 basis for subsequent fiber extraction.

[0009] In step S2, the enzymatic solution can destroy part of the lignin and hemicellulose in the bamboo fiber, making the fiber structure looser, which is conducive to the penetration and combination of other substances in the subsequent treatment process. At the same time, the enzymatic treatment can also remove some impurities in the fiber and improve the purity of the fiber.

[0010] In step S3, the alkaline solution can further remove impurities in the bamboo fiber, make its surface rougher, and increase the bonding force with other materials. At the same time, the alkaline treatment also helps to improve the hygroscopicity and dimensional stability of the bamboo fiber.

[0011] In step S4, the ions in the salt solution can react with the functional groups on the surface of the bamboo fiber to form chemical bonds, thereby enhancing the bonding force between the fibers. At the same time, the boiling process of the salt solution also helps to further remove moisture and volatile substances in the fibers, thereby improving the stability of the fibers.

[0012] In step S6, the wax is mixed with the primary product to form a thin waterproof layer on the surface of the bamboo fiber to prevent water penetration. At the same time, the wax material also has a certain lubricating effect, which helps to smoothly carry out the subsequent melt extrusion process.

[0013] In step S7, polylactic acid can be tightly combined with bamboo fiber to form a continuous network structure, thereby improving the strength and toughness of the product. Hydroxysilane coupling agent is a compound with a bifunctional group, one end of which can react with the hydroxyl group on the surface of bamboo fiber, and the other end can react with polymers such as polylactic acid. Therefore, it can act as a bridge, tightly connecting bamboo fiber and polymer together, and enhancing the bonding force of the interface. Glycerin can increase the flexibility and plasticity of the product; mica powder, as an inorganic filler, can enhance the mechanical strength of the product and improve the heat resistance of bamboo fiber; 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.

[0014] Preferably, the enzymatic hydrolysis solution is obtained by mixing xylanase, lignin degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent in a weight ratio of (0.2-0.5):(0.1-0.3):(0.2-0.5):(0.05-0.1):(0.05-0.15):10.

[0015] By adopting the above technical solution and optimizing the type and amount of enzymes in the enzymatic hydrolysate, the xylan, lignin and hemicellulose components in the bamboo fiber can be efficiently degraded, making the bamboo fiber structure looser, which is conducive to the penetration and combination of other substances in the subsequent processing steps. The bamboo fiber treated with the above enzymatic hydrolysate maintains the original high strength and toughness, and has good wear resistance and tear resistance. At the same time, the roughness and activity of the bamboo fiber surface are increased, making it easier to combine with other materials (such as polylactic acid, glycerol, etc.) to form a tight network structure, thereby improving the strength and toughness of the product.

[0016] 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.

[0017] By adopting the above technical solution, the dosage of sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water is optimized to further increase the stability and strength of the fiber. The sodium thiosulfate and sodium chloride in this ratio can adjust the ionic strength and pH value of the solution, which helps to enhance the stability of the fiber during the preparation process and prevent the fiber from being damaged by chemical changes. The synergistic effect of potassium phosphate, potassium chloride and potassium sulfate can further consolidate the fiber structure, improve the strength and toughness of the fiber, and make it more durable.

[0018] Preferably, the concentration of sodium hydroxide in the alkaline 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.

[0019] By adopting the above technical solution, the composition and concentration of the alkaline 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.

[0020] Preferably, the weight ratio of the semi-finished product, the polylactic acid, the hydroxysilane 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).

[0021] By adopting the above technical solutions, the weight of various raw materials is optimized, and the overall strength, waterproof and moisture-proof properties, tear resistance and toughness of environmentally friendly plant fibers are further enhanced, so that they can withstand greater weight and pressure and are not easily damaged. By adding an appropriate amount of polylactic acid to increase the overall strength and toughness of plant fibers, plant fibers 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 plant fibers, so that they can resist wear and tear in daily use, extending the service life of the product.

[0022] Preferably, the mica powder is modified mica powder, which is prepared by the following method: 1) mixing an aminosilane coupling agent and a solvent to obtain a mixed solution; 2) mixing mica powder and hydrogen peroxide, heating and stirring to react, to obtain hydroxylated mica powder; 3) The mixed solution and the hydroxylated mica powder are blended, ultrasonically heated at 70-90° C. for 1-2 hours, filtered, rinsed with ethanol, filtered, the filter residue is collected, and dried to obtain the modified mica powder.

[0023] Preferably, the weight parts of the raw materials used to prepare the modified mica powder are as follows: Aminosilane coupling agent 0.2-0.5 parts Solvent 5-10 parts 2-3 parts mica powder 4-6 parts of hydrogen peroxide.

[0024] By adopting the above technical solution, the dispersibility of mica powder is further improved, and the interfacial compatibility of plant fiber mica powder and polymer materials such as polylactic acid is poor, which easily leads to loose interface bonding, and defects and cracks are easily generated inside the fiber, thus affecting the overall performance of the plant fiber, such as strength and toughness. The functional groups of aminosilane coupling agent are introduced into the surface of the modified mica powder. These functional groups can form chemical bonds or hydrogen bonds with components such as polylactic acid and glycerol, thereby enhancing the interfacial bonding force, helping to improve the overall strength and toughness of the plant fiber and reduce the generation of internal defects and cracks.

[0025] Preferably, the aminosilane coupling agent includes at least one of 3-aminopropyltrimethylsilane, 3-aminopropyltriethoxysilane, N-(aminoethyl)-aminopropyltrimethoxysilane, N-(aminoethyl)-aminopropylmethyldimethoxysilane, N-(aminoethyl)-aminopropyltriethoxysilane and diethylenetriaminopropyltrimethoxysilane.

[0026] By adopting the above technical solution, the binding force between mica powder and polylactic acid, glycerin, castor oil, etc. is further improved, thereby improving the overall performance of the plant fiber.

[0027] Preferably, the wax comprises at least one of beeswax, palm wax or pineapple wax.

[0028] By adopting the above technical solution, the waterproof performance of bamboo fiber is further improved without affecting the degradation performance of bamboo fiber.

[0029] In the second aspect, the present application provides an environmentally friendly plant fiber for tableware, which adopts the following technical solution: The invention discloses an environmentally friendly plant fiber for tableware, wherein the plant fiber is used for preparing tableware.

[0030] By adopting the above technical solution, the lightness, waterproofness and moisture-proofness of tableware can be improved, and at the same time the tableware can be completely degraded.

[0031] In summary, this application has the following beneficial effects: 1. The present application optimizes the fiber structure of bamboo fiber by crushing, soaking, air-drying and multiple water spraying treatments, enhances the degree of interweaving and overall strength of the internal fibers, and then enzymatic hydrolysis treatment helps to remove part of the lignin and hemicellulose, making the fiber purer, while improving the hygroscopicity and biodegradability of the fiber. Then, the alkaline solution treatment further removes impurities on the fiber surface, improves the wettability and processability of the fiber, and then the salt solution boiling treatment helps to further stabilize and shape the fiber, and improves the toughness and strength of the fiber. By adding wax to the initial product, the waterproof barrier formed effectively reduces the absorption of water by the bamboo fiber, thereby improving the waterproof performance of the fiber. Finally, through the effects of polylactic acid, glycerol, mica powder, castor oil and chitosan, not only the strength and toughness of the fiber are enhanced, but also the complete degradability of the product is guaranteed. DETAILED DESCRIPTION Example

[0032] Polylactic acid was purchased from Dongguan Hongyi Plastic Technology Co., Ltd. The brand is American NatureWorks and the model is 4032D.

[0033] Example 1 An environmentally friendly plant fiber for tableware is prepared by the following method: S1. Collect 5000 g of bamboo, crush the bamboo, soak the crushed bamboo in a sodium hydroxide solution (mass fraction 10%) at a temperature of 40° C., take out, grind, and obtain ground bamboo powder; S2, soaking the dried bamboo in an enzymatic hydrolysis solution for 6 hours at a temperature of 50° C., filtering, and taking the filter residue, wherein the enzymatic hydrolysis solution is obtained by mixing xylanase, lignin degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent (water) in a weight ratio of 0.2:0.1:0.2:0.05:0.05:10; S3, soaking the filter residue in an alkaline solution for 2 hours at a temperature of 70°C, filtering, and taking the filter residue, wherein the concentration of sodium hydroxide in the alkaline solution is 10 g / L, the concentration of calcium hydroxide is 5 g / L, and the concentration of sodium bicarbonate is 15 g / L; S4, boiling the filter residue in a salt solution for 1-2 hours at a temperature of 100° C., filtering, and taking the filter residue, wherein the salt solution is obtained by mixing sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate, and water in a weight ratio of 0.2:1:0.5:0.5:1:12; S5, washing the filter residue with water, and drying it to obtain a primary product; S6, mixing 1000 g of the primary product and wax at 70° C., with the amount of wax being 40 g, to obtain a semi-finished product; S7. Mix 1000g of the semi-finished product, 150g of polylactic acid, 25g of hydroxysilane coupling agent (3-hydroxypropyltrimethoxysilane), 50g of glycerol, 200g of mica powder, 100g of castor oil and 100g of chitosan. The weight ratio of the semi-finished product, polylactic acid, hydroxysilane coupling agent, glycerol, mica powder, castor oil and chitosan is 20:3:0.5:1:4:2:2. After melt extrusion, environmentally friendly plant fibers for tableware are obtained.

[0034] The difference between Example 2-3 and Example 1 is that the raw material types, dosages and experimental parameters for preparing the environmentally friendly plant fibers for tableware are different. The specific differences are shown in Table 1: Table 1 Raw material types, dosages and experimental parameters of environmentally friendly plant fibers for tableware in Examples 1-3 Example 4 An environmentally friendly plant fiber for tableware. The difference between this embodiment and embodiment 1 is that the enzymatic solution is obtained by mixing xylanase, lignin degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent in a weight ratio of 0.2:0.2:0.2:0.2:0.2:10.

[0035] Example 5 An environmentally friendly plant fiber for tableware. The difference between this embodiment and embodiment 1 is that the enzymatic solution is obtained by mixing xylanase, lignin degrading enzyme, glyoxal oxidase and solvent in a weight ratio of 0.2:0.1:0.05:10.

[0036] Example 6 An environmentally friendly plant fiber for tableware. The difference between this embodiment and embodiment 1 is that sodium thiosulfate, sodium chloride, potassium phosphate, potassium chloride, potassium sulfate and water are mixed in a weight ratio of 0.5:0.5:0.5:0.5:0.5:12.

[0037] Example 7 An environmentally friendly plant fiber for tableware. The difference between this embodiment and embodiment 1 is that the alkaline solution is a sodium hydroxide solution with a concentration of 10 g / L.

[0038] Example 8 An environmentally friendly plant fiber for tableware. The difference between this embodiment and embodiment 1 is that the alkaline solution is a calcium hydroxide solution with a concentration of 5 g / L.

[0039] Example 9 An environmentally friendly plant fiber for tableware. The difference between this embodiment and embodiment 1 is that the mica powder is modified mica powder, which is prepared by the following method: 1) Mix 20 g of aminosilane coupling agent (3-aminopropyltrimethylsilane) and 500 g of solvent (ethanol) to obtain a mixed solution; 2) mixing 200 g of mica powder and 400 g of hydrogen peroxide, heating and stirring to react, to obtain hydroxylated mica powder; 3) The mixed solution and hydroxylated mica powder are blended, ultrasonically heated at 70° C. for 1 h, filtered, rinsed with ethanol, filtered, the filter residue is collected, and dried to obtain modified mica powder.

[0040] Example 10 An environmentally friendly plant fiber for tableware. The difference between this embodiment and embodiment 1 is that the mica powder is modified mica powder, which is prepared by the following method: 1) Mix 50 g of aminosilane coupling agent (N-(aminoethyl)-aminopropyltrimethoxysilane) and 100 g of solvent (ethanol) to obtain a mixed solution; 2) mixing 300 g of mica powder and 600 g of hydrogen peroxide, heating and stirring to react, to obtain hydroxylated mica powder; 3) The mixed solution and hydroxylated mica powder are blended, ultrasonically heated at 90° C. for 2 h, filtered, rinsed with ethanol, filtered, the filter residue is collected, and dried to obtain modified mica powder.

[0041] Comparative Example Comparative Example 1 An environmentally friendly plant fiber for tableware. The difference between this comparative example and Example 1 is that in step S1, a hydrochloric acid solution with a mass fraction of 10% is used instead of a sodium hydroxide solution.

[0042] Comparative Example 2 An environmentally friendly plant fiber for tableware. The difference between this comparative example and Example 1 is that: the bamboo powder is first ground according to step S3, and then according to step S2.

[0043] Comparative Example 3 An environmentally friendly plant fiber for tableware. The difference between this comparative example and Example 1 is that pure water is used instead of salt solution in step S4.

[0044] Comparative Example 4 An environmentally friendly plant fiber for tableware. The difference between this comparative example and Example 1 is that beeswax is not added in step S6.

[0045] Comparative Example 5 An environmentally friendly plant fiber for tableware. The difference between this comparative example and Example 1 is that PET replaces polylactic acid in step S7.

[0046] PET was purchased from Dongguan Julong Plastic Raw Materials Co., Ltd. The brand is American Basic Innovative Plastics (Shabit) and the grade is 830F.

[0047] Comparative Example 6 An environmentally friendly plant fiber for tableware. The difference between this comparative example and Example 1 is that hydroxymethyl cellulose is used instead of chitosan in step S7.

[0048] Detection method / test method Degradation performance test: The soil burial method was used for the test. A sample of 100g (M1) of environmentally friendly plant fiber for tableware that had been dried to a constant weight was buried in a container filled with soil. After 6 months of degradation, the soil-buried sample was taken out, cleaned, and dried to a constant weight (M2). The degradation rate was calculated according to the formula: Degradation rate = (M1-M2) / M1×100%.

[0049] Waterproof performance test: The environmentally friendly plant fibers for tableware prepared in Examples 1-10 and Comparative Examples 1-5 were hot-pressed at 180°C and 200t using a laminator to obtain packaging bags. Hot water at 90°C was added to the packaging bags, which were sealed and placed in an environment at 90°C for 24 hours to observe whether the packaging bags leaked. The hot-pressing temperature in Comparative Example 5 was 270°C.

[0050] Moisture-proof performance test: 10 g of the environmentally friendly plant fibers for tableware prepared in Examples 1-10 and Comparative Examples 1-5 were respectively soaked in pure water for 24 hours, taken out, the surface moisture was wiped off, and then weighed, and the weight gain was recorded.

[0051] Tensile strength: tested according to the method specified in GB / T 1040.1-2006.

[0052] Izod impact strength: tested according to the method specified in GB / T 1843-2008. The experimental data are shown in Table 2: Table 2 Experimental data of Examples 1-10 and Comparative Examples 1-5 Comparing Example 1 with Comparative Examples 1-4, the degradation rate of Comparative Examples 1-4 is slightly lower than that of Example 1; Comparative Examples 2 and 4 leak, and the weight increase of Comparative Examples 1-4 is also higher than that of Example 1. The tensile strength and cantilever beam 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 present application has good degradability, waterproof and moisture-proof properties and strength.

[0053] By comparing Example 1 with Comparative Examples 5-6, the degradation rate of Comparative Example 5 is greatly reduced, the degradation rate of Comparative Example 6 is lower than that of Example 1, and 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 in step 7, the environmentally friendly plant fiber for tableware can be further improved to have good degradability and waterproof and moisture-proof properties.

[0054] Comparing Example 1 with Example 4-5, the degradation rate of Example 4-5 is slightly lower than that of Example 1; the weight increase of Example 4-5 is also higher than that of Example 1, and the tensile strength and cantilever beam impact strength of Example 4-5 are lower than those of Example 1, indicating that by adjusting the composition and dosage of the enzymatic solution, the environmentally friendly plant fiber for tableware can be further improved to have good degradability, waterproof and moisture-proof properties and strength.

[0055] Comparing Example 1 with Example 6, the weight gain 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 be further improved in terms of good degradability, waterproof and moisture-proof properties, and strength.

[0056] Comparing Example 1 with Example 7-8, the weight increase of Example 7-8 is also higher than that of Example 1, and the tensile strength and Izod impact strength of Example 7-8 are lower than that of Example 1, indicating that by adjusting the composition and dosage of the alkaline solution, the environmentally friendly plant fiber for tableware can be further improved to have good waterproof and moisture-proof properties and strength.

[0057] Comparing Example 1 with Example 7-8, the degradation rate of Example 9-10 is higher than that of Example 1; the weight increase of Example 9-10 is also lower than that of Example 1, and the tensile strength and cantilever beam impact strength of Example 9-10 are lower than that of Example 1, indicating that the modified mica powder prepared by the present application can further improve the good degradability, waterproof and moisture-proof performance and strength of the environmentally friendly plant fiber for tableware.

[0058] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing environmentally friendly plant fibers for tableware, characterized in that: The method comprises the following preparation steps: S1, collecting bamboo, crushing the bamboo into flakes, soaking the crushed bamboo in an alkali solution at a temperature of 40-50° C., taking out, grinding, and obtaining ground bamboo powder; S2, soaking the dried bamboo in the enzymatic hydrolysis solution for 6-8 hours at a temperature of 50-60°C, filtering and taking the filter residue; S3, soak the filter residue in an alkaline solution for 2-3 hours at a temperature of 70-80°C, filter and take the filter residue; S4, boiling the filter residue in a salt solution for 1-2 hours at a temperature of 100-110° C., filtering, and taking the filter residue, wherein 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, and drying it to obtain a primary product; S6, mixing the primary product and wax at 70-80° C., wherein the amount of the wax is 4-8% by weight of the primary product, to obtain a semi-finished product; S7, mixing the semi-finished product, polylactic acid, hydroxy silane coupling agent, glycerin, mica powder, castor oil and chitosan, and performing melt extrusion to obtain environmentally friendly plant fibers for tableware.

2. The method for preparing environmentally friendly plant fiber for tableware according to claim 1, characterized in that: The enzymatic hydrolysis solution is obtained by mixing xylanase, lignin degrading enzyme, hemicellulase, glyoxal oxidase, catalase and solvent in a weight ratio of (0.2-0.5):(0.1-0.3):(0.2-0.5):(0.05-0.1):(0.05-0.15):

10.

3. The method for preparing environmentally friendly plant fiber for tableware according to claim 1, characterized in that: The weight ratio of the 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.

4. The method for preparing environmentally friendly plant fiber for tableware according to claim 1, characterized in that: The concentration of sodium hydroxide in the alkaline 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.

5. The method for preparing environmentally friendly plant fiber for tableware according to claim 1, characterized in that: The weight ratio of the semi-finished product, the polylactic acid, the hydroxysilane 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).

6. The method for preparing environmentally friendly plant fibers for tableware according to claim 1, characterized in that: The mica powder is modified mica powder, which is prepared by the following method: 1) Mixing the aminosilane coupling agent and the solvent to obtain a mixed solution; 2) Mixing mica powder and hydrogen peroxide, heating and stirring to react, thereby obtaining hydroxylated mica powder; 3) The mixed solution and hydroxylated mica powder are blended, ultrasonically heated at 70-90°C for 1-2 hours, filtered, rinsed with ethanol, filtered, the filter residue is collected, and dried to obtain modified mica powder.

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

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

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

10. A plant fiber prepared by the method for preparing environmentally friendly plant fiber for tableware according to any one of claims 1 to 9, characterized in that: The plant fiber is used for preparing tableware.

Images