Water-resistant and oil-resistant paper pulp molded tableware based on bagasse paper pulp and lotus stem residues and preparation method of water-resistant and oil-resistant paper pulp molded tableware

Abstract

The invention relates to water-resistant and oil-resistant paper pulp molded tableware based on bagasse paper pulp and lotus stem residues and a preparation method of the water-resistant and oil-resistant paper pulp molded tableware. Research finds that bagasse and lotus stem residues are used as raw materials to be compounded for use, an oil-proofing agent and a waterproof agent are added, lotus stem residue powder with high cellulose content is used as a raw material to achieve a synergistic effect with bagasse, the filling property and formability of the slurry are enhanced, and meanwhile, the lotus stem residue powder has high porosity, so that the filling property and formability of the slurry are improved. The antibacterial agent is beneficial to adsorption of a water-proofing agent and an oil-proofing agent, is beneficial to improvement of the barrier property of the molded tableware, and contains polyphenol antibacterial substances, so that the safety of the molded tableware is improved.

Description

Technical Field

[0001] The invention belongs to the field of polymer compound compositions, and particularly relates to water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue and a preparation method thereof. Background Art

[0002] With rising global environmental awareness and the advancement of the "dual carbon" goals, traditional disposable tableware is attracting increasing attention due to its difficulty in degradation and environmental pollution. Pulp molded tableware has emerged as a biodegradable alternative. However, current pulp molded tableware faces significant limitations in raw materials, performance, and processing, urgently requiring innovation and breakthroughs. Traditional pulp molded tableware mostly uses wood or bamboo pulp (such as CN114164715A), which has high raw material costs and a high dependence on forestry resources. It also has insufficient water resistance, with strength decreasing by over 40% after immersion for 24 hours; poor oil resistance, prone to oil penetration after contact; and generally lacks antibacterial properties. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems of high cost, poor oil resistance and grease resistance of molded tableware in the prior art, thereby providing a water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue and a preparation method. Through raw material compounding, fiber modification and structural optimization, the high performance and green sustainability of the tableware are achieved.

[0004] In order to solve the above technical problems, the present invention is achieved through the following technical solutions.

[0005] The water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue includes the following raw materials in parts by weight: 70-90 parts of bagasse, 10-30 parts of lotus stem residue powder, 5-6 parts of natural cellulose fibrils, 5-20 parts of alkyl ketene dimer waterproofing agent, and 4-6 parts of long-chain alkane mixed oil-proofing agent.

[0006] Furthermore, the particle size of the lotus stem residue powder is ≤200 mesh.

[0007] Furthermore, the average particle size of the alkyl ketene dimer waterproofing agent is ≤5 μm.

[0008] Furthermore, the average particle size of the alkyl ketene dimer waterproofing agent is ≤5 μm, and the average particle size of the natural cellulose fibrils is ≤100 mesh.

[0009] Furthermore, the water-resistant and oil-resistant pulp molded tableware has a uniform one-layer structure.

[0010] Furthermore, the water-resistant and oil-resistant pulp molded tableware can also be a multi-layer structure, including a base layer and a surface layer. The surface layer of the tableware is a waterproof and oil-proof layer including a long-chain alkane mixed oil-proof agent, and the base layer is a composite fiber layer including sugarcane bagasse and lotus stem residue.

[0011] Furthermore, the base layer includes a central base layer and a surface base layer, the surface base layer covers the central base layer, and the lotus stem residue powder content of the surface base layer is greater than the lotus stem residue powder content of the central base layer.

[0012] Furthermore, the thickness of the tableware can be designed according to specific needs. For example, the thickness of the surface layer can be 0.3-1.1 mm, and the thickness of the base layer can be 1.2-2.5 mm.

[0013] Furthermore, there is no limitation on the type of the natural cellulose fiber raw material; it may include one or more of ramie fiber, sisal fiber, jute fiber, bamboo fiber, and pineapple leaf fiber.

[0014] Furthermore, the natural cellulose fibrils have an average diameter of ≤200 nm and an average length of 500-2000 mm, and can also have a diameter in the range of 50-200 nm and a length of 500 μm-2000 μm.

[0015] Furthermore, the ratio of the lotus stem residue powder content in the surface base layer to the lotus stem residue powder content in the center base layer is 0.3-0.98, and more preferably 0.5-0.98.

[0016] A method for preparing water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue comprises the following steps: (1) Sugarcane bagasse is processed by mechanical beating to a freeness of 400-500 mL, and then 0.1%-0.5% by mass of cationic starch is added for surface modification to obtain sugarcane pulp; lotus stem bagasse powder is dried, and then mixed with the long-chain alkane oil-proof agent and ultrasonically dispersed and sieved to obtain the composite filler; (2) mixing the bagasse pulp, the composite filler, the natural cellulose fibrils, and the alkyl ketene dimer waterproofing agent in a double-screw mixer to form a uniform mixed slurry; (3) The mixed slurry is quantitatively supplied to a pulp molding device, the mixed slurry in the pulp molding device is vacuum-absorbed by a vacuum pump, and the mixed slurry is pressed, shaped, and dried at high temperature and high pressure by an upper mold and a lower mold of a setting machine to obtain the molded tableware pre-finished product.

[0017] (4) trimming the molded tableware pre-finished product to obtain the molded tableware finished product.

[0018] Furthermore, the mixed slurry in step (2) includes a first mixed slurry and a second mixed slurry, the ratio of the lotus stem residue powder content in the first mixed slurry to the lotus stem residue powder content in the second mixed slurry is 0.3-0.98, the first mixed slurry is used to prepare the center base layer, and the second mixed slurry is used to prepare the surface base layer.

[0019] Furthermore, the cationic starch includes but is not limited to one or more of dimethyl diallyl ammonium chloride modified starch, trimethyl benzyl ammonium chloride modified starch, epoxypropyl trimethyl ammonium chloride modified starch, and 2-hydroxy-3-(trimethylamino)propyl ether starch chloride.

[0020] Furthermore, the drying temperature in step (1) is 60-100°C.

[0021] Furthermore, the drying temperature is 105-110°C Furthermore, in step (3), the pressing temperature of the setting machine is 150-200° C., and the setting pressing time is 60-90 seconds.

[0022] Furthermore, in step (3), the pressing temperature of the setting machine is 150-165° C., and the setting pressing time is 60-90 seconds.

[0023] Furthermore, the molded tableware pre-finished product is trimmed and disinfected.

[0024] The present invention creatively compounds the sugarcane bagasse and the lotus stem bagasse as raw materials. On the one hand, the sugarcane bagasse has medium-long fibers of 0.65-2.17 mm to form a stable mesh network, and the sugarcane bagasse contains a certain amount of hemicellulose and lignin, which gives the slurry good thermoplasticity and formability. On the other hand, the lotus stem bagasse powder with short fibers and high cellulose content is used as a raw material to synergize with the sugarcane bagasse, thereby enhancing the filling and formability of the slurry. At the same time, the lotus stem bagasse powder has a high porosity, which is beneficial to the adsorption of the waterproof agent and the oil-proof agent, and is beneficial to improving the barrier properties of the molded tableware. It also contains polyphenol antibacterial substances, which is beneficial to improving the safety of the molded tableware.

[0025] The present invention has the following beneficial effects compared to the prior art: The present invention creatively combines the sugarcane bagasse with the raw materials, uses the sugarcane bagasse as a supporting skeleton, and fills the pores with lotus stem residue powder to form a dense structure. At the same time, natural cellulose fibrils are added to enhance the bonding force between fibers, which is beneficial to significantly improve the mechanical strength and anti-permeability. By controlling the content of lotus stem residue powder in the surface base layer to be greater than that in the center base layer, the high porosity of the lotus stem residue powder is utilized to improve the adsorption performance of the waterproof agent and the oil-proof agent, thereby improving the oil resistance and water resistance of the molded tableware. The alkyl ketene dimer waterproofing agent and the high porosity of the lotus stem residue powder work synergistically, so that tableware will not leak even if it is soaked in 80° C. hot water for 24 hours (water absorption rate ≤ 0.5%).

[0026] The long-chain alkane mixed oil-proof agent achieves uniform coating through ultrasonic dispersion, and the oil-proof grade reaches level 9.

[0027] The preparation method of the invention is simple; the bagasse is a by-product of sugar production and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention provides an overall process flow chart for the production of water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the following examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] Alkyl ketene dimer waterproofing agent: CAS number: 144245-85-2, item number M62608, Huayuan Mall; cationic starch: 2-hydroxy-3-(trimethylamino)propyl ether starch chloride, CAS number 56780-58-6, item number: R138358, Ron.

[0031] Example 1 A water-resistant and oil-resistant pulp molded tableware made of bagasse pulp and lotus stem residue comprises the following raw materials, measured by weight: 75 parts of bagasse, 10 parts of lotus stem residue powder, 5 parts of ramie fiber (average diameter 10 μm, average length 2000 μm), 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil-proofing agent (UC322).

[0032] The preparation method of the pulp molded tableware comprises the following preparation steps: (1) preparing raw materials according to the above raw material ratio, adding 1000 mL of water to treat the bagasse by mechanical beating to obtain a bagasse slurry with a freeness of 450 mL, and then adding a cationic starch aqueous solution with a mass fraction of 0.5% to the bagasse slurry according to a mass ratio of cationic starch to bagasse of 1:200 to perform surface modification treatment, wherein the modification treatment is heating and stirring, the modification temperature is 50°C, and the stirring time is 30 minutes, to obtain bagasse pulp; The lotus stem residue powder is dried at 60° C. to a moisture content of 5%, ground by a ball mill, and then mixed with an alkyl ketene dimer waterproofing agent according to the above raw material mass ratio. The mixture is dispersed at a 40 kHz ultrasonic frequency for 30 minutes and then sieved to obtain a composite filler of the lotus stem residue powder (200 mesh) and the alkyl ketene dimer waterproofing agent. (2) Bagasse pulp, composite filler, ramie fiber, and long-chain alkane mixed oil-proofing agent (UC322) were mixed in a double-screw mixer at a speed of 80 rpm and a mixing time of 20 minutes to form a uniform mixed slurry; (3) The mixed slurry is quantitatively supplied to the pulp molding device, and the vacuum degree is -0.08 MPa for 15 seconds. A hot pressing molding process is adopted with an upper and lower mold temperature of 160°C and a pressure of 20 MPa for 60 seconds. After demolding, the pre-finished product is naturally cooled; (4) After trimming the pre-finished product, it is sterilized by ultraviolet radiation (wavelength 254nm, irradiation intensity 80μW / cm 2 , time 15 minutes) to obtain a molded tableware product with a thickness of 3 mm.

[0033] Example 2 The preparation method of the pulp molded tableware comprises the following preparation steps: Preparation of the first mixed slurry: The following raw materials are mixed uniformly in a double-screw mixer at a speed of 80 rpm for 20 minutes to obtain a first mixed slurry. 73 parts of sugarcane bagasse, 12 parts of lotus stem residue powder, 5 parts of ramie fiber, 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil repellent (UC322) are included. The mixture is mixed uniformly in a double-screw mixer at a speed of 80 rpm for 20 minutes to obtain a first mixed slurry. (1) Raw materials were prepared according to the above raw material ratios, 1000 mL of water was added, and the bagasse was treated by mechanical beating to obtain a bagasse slurry with a freeness of 450 mL. Then, a cationic starch aqueous solution with a mass fraction of 0.5% was added to the bagasse slurry at a mass ratio of cationic starch to bagasse of 1:200 to perform surface modification treatment. The modification treatment was heating and stirring at a modification temperature of 50°C and a stirring time of 30 minutes to obtain bagasse pulp. The lotus stem residue powder is dried at 60° C. to a moisture content of 5%, ground by a ball mill, and then mixed with an alkyl ketene dimer waterproofing agent according to the above raw material mass ratio. The mixture is dispersed at a 40 kHz ultrasonic frequency for 30 minutes and then sieved to obtain a composite filler of the lotus stem residue powder (200 mesh) and the alkyl ketene dimer waterproofing agent. Mixing bagasse pulp, composite filler, ramie fiber, and long-chain alkane mixed oil-proofing agent (UC322) in a double-screw mixer at a speed of 80 rpm for 20 minutes to obtain a first mixed slurry; Preparation of the second mixed slurry: The invention comprises the following raw materials: 72 parts of sugarcane bagasse, 13 parts of lotus stem residue powder, 5 parts of ramie fiber, 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil-proofing agent (UC322).

[0034] (1) Raw materials were prepared according to the above raw material ratios, 1000 mL of water was added, and the bagasse was treated by mechanical beating to obtain a bagasse slurry with a freeness of 450 mL. Then, a cationic starch aqueous solution with a mass fraction of 0.5% was added to the bagasse slurry at a mass ratio of cationic starch to bagasse of 1:200 to perform surface modification treatment. The modification treatment was heating and stirring at a modification temperature of 50°C and a stirring time of 30 minutes to obtain bagasse pulp. The lotus stem residue powder is dried at 60° C. to a moisture content of 5%, ground by a ball mill, and then mixed with an alkyl ketene dimer waterproofing agent according to the above raw material mass ratio. The mixture is dispersed at a 40 kHz ultrasonic frequency for 30 minutes and then sieved to obtain a composite filler of the lotus stem residue powder (200 mesh) and the alkyl ketene dimer waterproofing agent. (2) mixing bagasse pulp, composite filler, ramie fiber, and long-chain alkane mixed oil-proofing agent (UC322) in a double-screw mixer at a speed of 80 rpm and a mixing time of 20 minutes to obtain a second mixed slurry; The first mixed slurry and the second mixed slurry are quantitatively supplied to the pulp molding device in a volume ratio of 2:1 respectively, and the mixed slurry in the pulp molding device is vacuum-absorbed by a vacuum pump (vacuum degree -0.08 MPa, suction for 15 seconds), and the mixed slurry is pressed and shaped by the upper and lower molds of the shaping machine at 160°C for 60 seconds and dried to obtain the molded tableware pre-finished product.

[0035] (4) After trimming the pre-finished product, it is sterilized by ultraviolet radiation (wavelength 254nm, irradiation intensity 80μW / cm 2 , time 15 minutes) to obtain a molded tableware product with a surface layer thickness of 1 mm and a base layer thickness of 2 mm.

[0036] Example 3 The difference from Example 2 is that the raw material ratio of the first mixed slurry is 74 parts of sugarcane bagasse, 11 parts of lotus stem residue powder, 5 parts of ramie fiber, 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil repellent (UC322).

[0037] Example 4 The difference from Example 2 is that the first mixed slurry ratio is 75 parts of sugarcane bagasse, 10 parts of lotus stem residue powder, 5 parts of ramie fiber, 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil-proofing agent (UC322).

[0038] Example 5 The difference from Example 2 is that the raw material ratio of the second mixed slurry is 71 parts of sugarcane bagasse, 14 parts of lotus stem residue powder, 5 parts of ramie fiber, 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil repellent (UC322).

[0039] Example 6 The difference from Example 2 is that the raw material ratio of the second mixed slurry is 70 parts of sugarcane bagasse, 15 parts of lotus stem residue powder, 5 parts of ramie fiber, 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil-proofing agent (UC322).

[0040] Example 7 The difference from Example 2 is that the first mixed slurry and the second mixed slurry are quantitatively supplied to the pulp molding device in a volume ratio of 2.5:0.3, and finally a molded tableware product with a surface layer thickness of 0.3 mm and a base layer thickness of 2.5 mm is obtained.

[0041] Example 8 The difference from Example 2 is that the first mixed slurry and the second mixed slurry were quantitatively supplied to the pulp molding device in a volume ratio of 1.9:1.1, and finally a molded tableware product with a surface layer thickness of 1.1 mm and a base layer thickness of 1.9 mm was obtained.

[0042] Example 9 The difference from Example 2 is that the first mixed slurry and the second mixed slurry are quantitatively supplied to the pulp molding device in a volume ratio of 1.2:1.1, and finally a molded tableware product with a surface layer thickness of 1.1 mm and a base layer thickness of 1.2 mm is obtained.

[0043] Comparative Example 1: The difference from Example 1 is that the raw material ratio is 85 parts of sugarcane bagasse, 5 parts of ramie fiber, 5 parts of alkyl ketene dimer waterproofing agent, and 5 parts of long-chain alkane mixed oil repellent (UC322). The speed is set at 80 rpm in a double-screw mixer for 20 minutes to form a uniform mixed slurry; Comparative Example 2: The difference from Example 1 is that the long-chain alkane mixed oil-proofing agent (UC322) is not added.

[0044] Comparative Example 3: The difference from Example 1 is that the raw material ratio contains 50 parts of sugarcane bagasse and 35 parts of lotus stem residue powder.

[0045] Comparative Example 4: The difference from Example 1 is that the raw material ratio is 95 parts of sugarcane bagasse and 5 parts of lotus stem residue powder.

[0046] Comparative Example 5: The difference from Example 1 is that no alkyl ketene dimer waterproofing agent is added.

[0047] Comparative Example 6: The difference from Example 1 is that no ramie fiber is added.

[0048] Performance testing: Tensile strength: Pre-treated for 4 hours in a humidity control box according to GB / T10739 standard conditions, and a biaxial testing machine was used to simulate complex stress states.

[0049] Water resistance: Measure the water absorption after immersion for 24 hours. Water absorption = (mass after immersion - initial mass) / initial mass * 100%.

[0050] Oil resistance: measured according to GB / T19223-2003 standard.

[0051] Table 1 Performance test results of Examples 1-5 and Comparative Examples 1-6 Tensile strength (MPa) Water absorption rate (%) Oil resistance grade Example 1 38.5 0.31 Level 8 Example 2 38.8 0.20 Level 9 Example 3 37.0 0.22 Level 9 Example 4 39.1 0.25 Level 9 Example 5 38.2 0.18 Level 9 Example 6 38.2 0.16 Level 9 Example 7 39.0 0.30 Level 8 Example 8 37.5 0.15 Level 9 Example 9 37.2 0.18 Level 9 Comparative Example 1 25.1 5.01 Level 6 Comparative Example 2 38.5 1.52 Level 7 Comparative Example 3 29.4 0.33 Level 9 Comparative Example 4 32.6 4.07 Level 7 Comparative Example 5 30.3 20.12 Level 7 Comparative Example 6 32.1 0.31 Level 8 The results show that the molded tableware obtained in the embodiment of the present invention is superior to the comparative example in terms of tensile strength, water absorption rate, and oil resistance. The main reason is that the sugarcane bagasse and the lotus stem residue are compounded as raw materials, and the sugarcane bagasse pulp is used as a supporting skeleton to fill the pores and form a dense structure, which is conducive to significantly improving the mechanical strength and anti-permeability; the lotus stem residue powder has a high porosity, which is conducive to improving the adsorption performance of the waterproof agent and the oil-proof agent, and improving the oil resistance and water resistance of the molded tableware. It can be seen from the experimental results of Examples 1-2 that the content of lotus stem residue powder in the surface base layer improves the oil resistance grade and oil absorption rate of the molded tableware, which has better performance than Example 1, and has better tensile properties. It can be seen from the experimental results of Examples 2-4 that the content of the lotus stem residue powder in the first mixed slurry is increased, and the water absorption rate does not change significantly, but the tensile strength is reduced due to the short length of the lotus stem residue powder fibers; in Example 4, the content of the bagasse pulp in the first mixed slurry is increased, and the water absorption rate does not decrease significantly, and the overall tensile strength is slightly increased, which is because the fibers in the bagasse pulp are conducive to improving the formability; in Example 5, the content of the lotus stem residue powder in the second mixed slurry is increased, and the water absorption rate is reduced, and the corresponding performance is improved. In Comparative Example 1, the lotus stem residue powder was not added to the raw materials, and the tensile strength and water and oil resistance were significantly reduced; according to the experimental results of Comparative Examples 2 and 5, it can be seen that in Comparative Example 2, the long-chain alkane mixed oil-proofing agent was not added, the oil resistance was reduced, and the water resistance was also reduced to a certain extent compared with Example 1, but the water resistance was improved compared with Comparative Example 1. This is because the lotus stem residue powder has a high porosity, which is conducive to the adsorption of the water-proofing agent. In Comparative Example 5, no water-proofing agent was added, and the water resistance and oil resistance were simultaneously reduced, further illustrating that the synergistic effect of the long-chain alkane mixed oil-proofing agent and the water-proofing agent can simultaneously improve the water resistance and oil resistance of the material; the experimental results of Comparative Examples 3-4 show that the tensile properties of the molded tableware are significantly reduced compared with Example 1 when the sugarcane bagasse pulp is less than 55 parts, and the tensile strength is not improved when the sugarcane bagasse pulp is higher than 65 parts, and the water and oil resistance are reduced; from the experimental results of Example 1 and Comparative Example 6, it can be seen that the tensile strength is reduced when the natural cellulose fibrils are not added.

[0052] In summary, the present invention creatively compounds the sugarcane bagasse and the lotus stem bagasse as raw materials, controls the amount of the sugarcane bagasse pulp and the lotus stem bagasse powder, controls the content of the lotus stem bagasse powder in the surface base layer to be greater than that in the center base layer, utilizes its high porosity to improve the adsorption performance of the waterproof agent and the oil-proof agent, improves the oil resistance and water resistance of the molded tableware, and at the same time ensures the tensile strength of the molded tableware.

[0053] The above detailed description of the analytical methods involved in the present invention provides a detailed introduction. It should be noted that the above description is intended solely to help those skilled in the art better understand the methods and concepts of the present invention, and is not intended to limit the relevant content. Without departing from the principles of the present invention, those skilled in the art may make appropriate adjustments or modifications to the present invention, and such adjustments and modifications shall also fall within the scope of protection of the present invention.

Claims

1. A water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue, characterized in that: The waterproofing agent is prepared from the following raw materials in parts by weight: 70-90 parts of sugarcane bagasse, 10-30 parts of lotus stem residue powder, 5-6 parts of natural cellulose fibrils, 5-20 parts of alkyl ketene dimer waterproofing agent, and 4-6 parts of long-chain alkane mixed oil-proofing agent.

2. The water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue according to claim 1, characterized in that: The particle size of the lotus stem residue powder is ≤200 meshes.

3. The water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue according to claim 1, characterized in that: The average particle size of the alkyl ketene dimer waterproofing agent is ≤5 μm.

4. The water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue according to claim 1, characterized in that: The average particle size of the alkyl ketene dimer waterproofing agent is ≤5 μm, and the average particle size of the natural cellulose fibrils is ≤100 meshes.

5. The water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue according to claim 1, characterized in that: The water-resistant and oil-resistant pulp molded tableware has a uniform one-layer structure.

6. The water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue according to claim 1, characterized in that: The water-resistant and oil-resistant pulp molded tableware has a multi-layer structure, including a base layer and a surface layer; the surface layer of the tableware is a waterproof and oil-proof layer including a long-chain alkane mixed oil-proof agent, and the base layer is a composite fiber layer including sugarcane bagasse and lotus stem residue.

7. The water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue according to claim 6, characterized in that: The base layer comprises a central base layer and a surface base layer, wherein the surface base layer covers the central base layer, and the lotus stem residue powder content of the surface base layer is greater than that of the central base layer.

8. The method for preparing water-resistant and oil-resistant pulp molded tableware based on bagasse pulp and lotus stem residue according to any one of claims 1 to 7, characterized in that: The steps include: (1) The sugarcane bagasse is processed by mechanical beating to a freeness of 400-500 mL, and then 0.1%-0.5% by mass of cationic starch is added for surface modification to obtain sugarcane bagasse pulp; the lotus stem residue powder is dried, and then mixed with the long-chain alkane oil-proof agent to obtain the composite filler by ultrasonic dispersion and screening; (2) mixing the bagasse pulp, the composite filler, the natural cellulose fibrils, and the alkyl ketene dimer waterproofing agent in a double-screw mixer to form a uniform mixed slurry; (3) quantitatively supplying the mixed slurry to a pulp molding device, vacuum-absorbing water from the mixed slurry in the pulp molding device by a vacuum pump, and pressing, shaping, and drying the mixed slurry at high temperature and high pressure by an upper mold and a lower mold of a setting machine to obtain the molded tableware pre-finished product; (4) trimming the molded tableware pre-finished product to obtain the molded tableware finished product.

9. The preparation method according to claim 8, characterized in that The mixed slurry in step (2) includes a first mixed slurry and a second mixed slurry, the ratio of the lotus stem residue powder content in the first mixed slurry to the lotus stem residue powder content in the second mixed slurry is 0.3-0.98, the first mixed slurry is used to prepare the center base layer, and the second mixed slurry is used to prepare the surface base layer.

10. The preparation method according to claim 8, characterized in that The drying temperature in step (1) is 60-100°C; Alternatively, in step (3), the pressing temperature of the setting machine is 150-200° C., and the setting pressing time is 60-90 seconds; Alternatively, the alkyl ketene dimer waterproofing agent is stirred and mixed with the natural cellulose fibrils for 15-30 minutes.

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