Preparation method of novel plant fiber molded product, product and application

Abstract

The invention relates to the field of fiber molded products, and discloses a preparation method of a novel plant fiber molded product, the product and application, and the preparation method comprises the following steps: crushing plant fibers, and carrying out rheology modification on the crushed plant fibers by using a rheology modification material to obtain modified fibers; the mass ratio of the plant fiber to the rheology modified material is 1: (0.005-0.3); mixing the modified fibers with a binder and a waterproof agent to obtain a plant fiber molding blank; the mass ratio of the modified fiber to the binder is 1: (0.01-0.2); extruding the plant fiber molding blank into a mold for molding by utilizing extrusion equipment to obtain a molded plant fiber prefabricated product; and demolding the plant fiber prefabricated product to obtain the plant fiber molded product. The obtained product is good in appearance state and mechanical property, a continuous process is adopted, the production efficiency is obviously improved, and meanwhile, the carbon emission of the product is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fiber molded products, in particular to a preparation method of a new type of plant fiber molded product, the new type of plant fiber molded product and application. BACKGROUND

[0003] Wet pressing plant fiber molding is prepared by using natural plant fiber as raw material, supplemented with dry strength agent, wet strength agent, waterproof and oil-proof agent, etc., through processes such as pulping, beating, sizing, suction, molding, cutting, etc. Because plant fiber is easy to entangle and has poor fluidity, a large amount of water is needed for sizing, and then suction filtration is needed to obtain a relatively complete and uniform wet embryo. This results in a longer process for wet pressing plant fiber molding and a large amount of heat (steam, electricity) is needed to remove the water.

[0004] The prior art all adopts the method of wet pressing plant fiber molding, for example: patent CN102465477A discloses a production device for paper pulp molded products and a method for preparing molded products by using the device, which discloses three devices of injection molding, wet embryo transfer and hot pressing molding. Although it does not mention the steps of pulping, beating, sizing and cutting, these steps are indispensable in the production process of paper pulp molding, and the process has not been simplified, and the wet embryo is directly heated, which cannot reduce the energy consumption for water removal; patent CN103556547A discloses a paper pulp molded packaging product and a manufacturing method thereof, which is manufactured by using bagasse and waste paper as raw materials, and the manufacturing method includes six steps of pulping, molding (suction, dehydration), demolding and hot pressing shaping. The process and energy consumption have not been significantly improved; patent CN118207749A discloses a preparation method of paper pulp molded product, which includes the steps of preparing reinforced particles, preparing primary pulp, preparing secondary pulp and molding. The process in this technical solution is basically the same as that of traditional paper pulp molding, and the moisture content of the wet embryo of the paper pulp molding is also not significantly different from that of the traditional paper pulp molding.

[0005] In summary, the existing wet pressing paper pulp molding process has the problems of long process and high energy consumption (about 12000kWh per ton of product), which seriously affects the carbon footprint of the wet pressing paper pulp molding product, so technical innovation is needed to further reduce the carbon emissions of paper pulp molding. SUMMARY

[0006] The purpose of the present application is to provide a preparation method of a new type of plant fiber molded product, the product and application, which adopts extrusion injection molding to obtain a new type of plant fiber molded product, uses a continuous process, and significantly improves the production efficiency while reducing carbon emissions.

[0007] To achieve the above purpose, the technical scheme adopted by the present application is as follows: a preparation method of a new type of plant fiber molded product, comprising the following steps: Step one: crushing the plant fiber, using rheological modification material to modify the crushed plant fiber, and obtaining modified fiber; The rheological modification includes at least one of chemical crosslinking modification, chemical grafting modification, and physical blending modification. The mass ratio of the plant fiber to the rheological modification material is 1:0.005-0.3. Step two: dry mixing the modified fiber with a binder and a waterproof agent to obtain a plant fiber molding forming blank; The mass ratio of the modified fiber to the binder is 1:0.01-0.2. Step three: using an extrusion device to extrude the plant fiber molding forming blank into a mold to form a molded plant fiber preform; Step four: demolding the plant fiber preform to obtain a plant fiber molded product.

[0008] In the above scheme, in step one: The method for crushing the plant fiber includes at least one of dry crushing, hydraulic pulping, and refining. The rheological modification material includes at least one of a mixture of sodium octenyl succinate starch and maleic anhydride, and montmorillonite, cellulose derivatives, glyoxal, citric acid, silicon dioxide, glycerol, and water.

[0009] In the above scheme, in step two: The mixing device used in the dry mixing includes at least one of a high-speed mixer, a planetary mixer, a kneader, an open mill, a twin-screw extruder, and a single-screw extruder. The temperature during the dry mixing is maintained at 25-80°C, and the mixing time is 10-60 minutes.

[0010] In the above scheme, in step two: The form of the plant fiber molding forming blank is configured to be at least one of a particle, a strip, and a lump.

[0011] In the above scheme, in step three: the extrusion temperature of the extrusion device is configured to be 25-120°C, and the extrusion pressure is configured to be 0.1-2 MPa. During the extrusion forming, the mold temperature of the extrusion device is configured to be 25-250°C, and the heating mode of the mold includes at least one of electric heating, steam heating, infrared heating, hot air heating, and microwave heating.

[0012] In the above scheme, the mass ratio of the plant fiber to the rheological modification material is 1:0.005-0.2.

[0013] In the above scheme, the binder includes at least one of natural latex, cationic modified starch, polyethylene oxide, sodium carboxymethyl cellulose, and gelatin; the mass ratio of the rheology-modified plant fiber to the binder is 1:0.05-0.2.

[0014] In the above scheme, after demolding the plant fiber molded preform in step four, the following steps are also included: The pre-molded plant fiber product is cut to obtain a molded plant fiber product.

[0015] The present invention also provides the application of the novel plant fiber molded articles obtained by the above preparation method in plant fiber molded articles.

[0016] The present invention also provides a novel plant fiber molded article, which is obtained by the above-described preparation method.

[0017] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: Using rheology-modified plant fibers as the main raw material, they are dry-mixed with binders, waterproofing agents, and other additives. The resulting product is then obtained through extrusion injection molding. The flowability of the plant fiber molding preform is optimized by screening the types of rheology-modified materials and adjusting the ratio of plant fibers to these materials. This ensures the preform can be easily extruded through the extrusion equipment. Adjusting the ratio of rheology-modified plant fibers to binders ensures uniform fiber dispersion in the molded product, preventing surface adhesion or cracking of the new plant fibers. The resulting product exhibits excellent appearance and mechanical properties. Furthermore, the continuous process significantly improves production efficiency and greatly reduces carbon emissions. Attached Figure Description

[0018] Appendix Figure 1 This is a flowchart of a method for preparing a novel plant fiber molded article according to an embodiment of the present invention. Detailed Implementation

[0019] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0020] like Figure 1 As shown in the embodiments of this application, a novel method for preparing plant fiber molded articles is provided, comprising the following steps: Step 1: Crush the plant fibers and use rheological modification materials to modify the crushed plant fibers to obtain modified fibers; The rheological modification includes at least one of chemical cross-linking modification, chemical grafting modification, and physical blending modification. The mass ratio of the plant fiber to the rheological modification material is 1 to 0.005 to 0.3. Step two: dry mixing the modified fiber with a binder and a waterproofing agent to obtain a plant fiber molding forming blank; The mass ratio of the modified fiber to the binder is 1 to 0.01 to 0.2. Step three: extruding the plant fiber molding forming blank into a mold by using an extrusion device to perform extrusion forming, to obtain a formed plant fiber preform; Step four: demolding the plant fiber preform to obtain a plant fiber molded product.

[0021] The preparation method of the novel plant fiber molded product provided in the embodiment uses rheologically modified plant fiber as the main raw material, dry mixes the rheologically modified plant fiber with a binder, a waterproofing agent and other additives, and adopts extrusion injection molding to obtain a novel plant fiber molding forming product. The flowability of the plant fiber molding blank is optimized by screening the types of rheological modifiers and adjusting the ratio of the plant fiber to the rheological modifier, so that the plant fiber molding blank can be smoothly extruded by the extrusion device. The ratio of the rheologically modified plant fiber to the binder is adjusted to make the fibers in the plant fiber molded product uniformly dispersed, and the product surface is free of paste hanging or through cracking. The above scheme can greatly reduce the preparation energy consumption.

[0022] In a preferred embodiment, in the step one: The method for crushing the plant fiber includes at least one of dry crushing, hydraulic pulping and refining. The rheological modification material includes at least one of sodium octenyl succinate starch, a mixture of maleic anhydride, montmorillonite, cellulose derivatives, glyoxal, citric acid, silicon dioxide, glycerol and water. The rheological modification material is not a rheological modifier in the traditional sense, but a material that can achieve the above rheological modification in a broad sense.

[0023] In a preferred embodiment, in the step two: The binder is at least one of natural latex, cationic modified starch, polyethylene oxide, sodium carboxymethyl cellulose and gelatin, and the mass ratio of the modified fiber to the binder is 1 to 0.05 to 0.2. The binder replaces the hydrogen bond formed by the plant fiber and water in the wet forming process, so as to bond the loose plant fiber into a whole.

[0024] The waterproof agent is at least one of alkyl ketene dimer (AKD), polyacrylamide, acrylic emulsion, PE wax emulsion and other waterproof agents capable of improving the contact angle of the plant fiber molded product, and the mass ratio of the plant fiber to the waterproof agent is 1:0.001-0.03. The waterproof agent can improve the contact angle of the plant fiber molded product, so that the plant fiber molded product can maintain the original structure and strength even when it is in humid weather or contacts water.

[0025] The mixing device used in the dry mixing process includes at least one of a high-speed mixer, a planetary mixer, a kneader, an open mill, a double-screw extruder and a single-screw extruder. The temperature during the dry mixing process is maintained at 25-80℃, and the mixing time is 10-60 minutes.

[0026] In the preferred embodiment, in step two: The form of the plant fiber molded forming blank is at least one of a particle, a long strip and a lump.

[0027] In the preferred embodiment, in step three, the extrusion temperature of the extrusion device is configured to be 25-120℃, and the extrusion pressure is configured to be 0.1-2 MPa. In the extrusion forming process, the mold temperature of the extrusion device is configured to be 25-250℃, and the heating mode of the mold includes at least one of electric heating, steam heating, infrared heating, hot air heating and microwave heating.

[0028] In the preferred embodiment, the mass ratio of the plant fiber to the rheology modifying material is 1:0.005-0.2.

[0029] In the preferred embodiment, the mass ratio of the rheology modified plant fiber to the adhesive is 1:0.05-0.2.

[0030] In the preferred embodiment, in step four, after the plant fiber preform is demolded, the method further includes: The plant fiber preform after demolding is cut to obtain a plant fiber molded product.

[0031] The application also provides a novel plant fiber molded product obtained by the above preparation method for use in a product containing the molded product.

[0032] The application also provides a novel plant fiber molded product obtained by the above preparation method.

[0033] The application is further described below through examples and comparative examples.

[0034] Example 1 Step one, 1 kg of coniferous wood pulp board is crushed and mixed with 100 g of glycerol, silicon dioxide, maleic anhydride, and sodium octenyl succinate starch (mass ratio of 4:2:0.5:3.5) to prepare rheology-modified plant fibers; Step two, the plant fibers modified in step one are mixed with 100 g of natural latex and 50 g of PE wax emulsion by a high-speed mixer at a mixing temperature of 100°C for 30 minutes to prepare a plant fiber molding blank in a lump shape; wherein the PE wax emulsion is used as a waterproofing agent.

[0035] Step three, a single-screw extruder is set to a temperature of 80°C, and the plant fiber molding blank is injected into a steel mold at an extrusion pressure, i.e., injection pressure, of 1 MPa. The mold temperature is controlled at 130°C by electrical heating to form the plant fiber molding blank; Step four, the formed plant fiber molding blank is demolded and cut to obtain a finished product.

[0036] The finished product is cut to a certain size according to the industry standard of the American Pulp and Paper Technical Association (TAPPI) to take a typical structural part, and a universal testing machine is used to test the compression strength according to the static compression test method for packaging cushioning materials GB / T8168-2088.

[0037] The plant fiber molding product prepared in this example has a full and complete structure, no obvious pulp hanging and cracking on the material surface, a product forming energy consumption of 4500 kWh, and a compression strength of 3.1 MPa.

[0038] Example 2 The preparation process is basically the same as in Example 1, except that: The total weight of glycerol, silicon dioxide, maleic anhydride, and sodium octenyl succinate starch in step one is replaced by 5 g.

[0039] The plant fiber molding product prepared in this example has a basically complete structure, no obvious pulp hanging and cracking on the material surface, a product forming energy consumption of 4200 kWh, and a compression strength of 2.5 MPa.

[0040] Example 3 The preparation process is basically the same as in Example 1, except that: The total weight of glycerol, silicon dioxide, maleic anhydride, and sodium octenyl succinate starch in step one is replaced by 200 g.

[0041] The plant fiber molding product prepared in this example has a full and complete structure, no obvious pulp hanging and cracking on the material surface, a product forming energy consumption of 5900 kWh, and a compression strength of 3.7 MPa.

[0042] Example 4 The preparation process is basically the same as in Example 1, with the only difference being that: The glycerol in step one is replaced by water.

[0043] The plant fiber molded product prepared in this example is also structurally full and complete, and the material surface has no obvious pulp hanging and cracking. The energy consumption of the formed ton product is 7800 kWh, and the compressive strength is 3.0 MPa.

[0044] Comparative Example 1 The preparation process is basically the same as in Example 1, with the only difference being that: The total weight of glycerol, silicon dioxide, maleic anhydride, and sodium octenyl succinate starch in step one is replaced by 4g.

[0045] It can be found that the mass ratio of plant fiber to rheological modifier in Comparative Example 1 is 1 to 0.004, and the plant fiber molded product prepared in this example is not complete in structure, with large area voids. The energy consumption of the formed ton product is 4150 kWh, and the compressive strength is 1.4 MPa.

[0046] Example 5 The preparation process is basically the same as in Example 1, with the only difference being that: The mixture of 100g glycerol, silicon dioxide, maleic anhydride, and sodium octenyl succinate starch (mass ratio of 4:2:0.5:3.5) in step one is replaced by 100g montmorillonite, maleic anhydride, and sodium octenyl succinate starch (mass ratio of 6:0.5:3.5).

[0047] The plant fiber molded product prepared in this example is also structurally full and complete, and the material surface has no obvious pulp hanging and cracking. The energy consumption of the formed ton product is 4300 kWh, and the compressive strength is 3.0 MPa.

[0048] Comparative Example 2 The preparation process is basically the same as in Example 1, with the only difference being that: The mixture of 100g glycerol, silicon dioxide, maleic anhydride, and sodium octenyl succinate starch (mass ratio of 4:2:0.5:3.5) in step one is replaced by 100g glycerol, silicon dioxide, and sodium octenyl succinate starch (mass ratio of 4:2:4).

[0049] The plant fiber molded product prepared in Comparative Example 2 has a jamming and no discharge condition during extrusion. Through comparison between Comparative Example 2 and Example 1, it is shown that maleic anhydride is indispensable.

[0050] Comparative Example 3 The preparation process is basically the same as in Example 1, with the only difference being that: The mixture of 100 g of glycerol, silica, maleic anhydride, and sodium octenyl succinate starch (mass ratio of 4:2:0.5:3.5) in step one is replaced by 100 g of glycerol, silica, and maleic anhydride (mass ratio of 4:2:4).

[0051] The plant fiber molded product prepared in Comparative Example 3 has an incomplete structure with a large area of voids, the energy consumption of the molding ton product is 4450 kWh, and the compressive strength is 1.3 MPa. By comparing Comparative Example 3 with Example 1, it is shown that sodium octenyl succinate starch is indispensable.

[0052] Example 6 The preparation process is basically the same as in Example 1, except that: The weight of natural latex in step two is replaced by 200 g; The plant fiber molded product prepared in this example has a full and complete structure; there is no obvious pulp hanging and cracking, the energy consumption of the molding ton product is 4680 kWh, and the compressive strength is 4.0 MPa.

[0053] Example 7 The preparation process is basically the same as in Example 1, except that: The weight of natural latex in step two is replaced by 50 g; The plant fiber molded product prepared in this example has a full and complete structure; there is no obvious pulp hanging, and there is one crack with a width of less than 0.5 mm and a length of 5 mm, the energy consumption of the molding ton product is 4610 kWh, and the compressive strength is 2.5 MPa.

[0054] A crack of less than 100 square millimeters meets the requirements of the paper pulp molding standard BB / T0045-2021.

[0055] Example 8 The preparation process is basically the same as in Example 1, except that: The weight of natural latex in step two is replaced by 10 g; The plant fiber molded product prepared in this example has a full and complete structure; there is no obvious pulp hanging, and there are three cracks with a width of less than 3 mm and a length of 12 mm, 28 mm, and 29 mm, respectively, the energy consumption of the molding ton product is 4590 kWh, and the compressive strength is 2.1 MPa.

[0056] Comparative Example 4 The preparation process is basically the same as in Example 1, except that: The weight of natural latex in step two is replaced by 9 g; It can be observed that in Comparative Example 4, the modified fiber to binder mass ratio was 1:0.009. The plant fiber molded product prepared in Comparative Example 4 had a full and complete structure; there was no obvious slurry buildup, but a through-crack was present. The energy consumption per ton of product was 4590 kWh, and the compressive strength was 1.3 MPa. A comparison between Comparative Example 4 and Example 1 shows that products obtained with a modified fiber to binder mass ratio greater than 1:0.01 do not meet industry standards.

[0057] Comparative Example 5 The preparation process is basically the same as in Example 1, with the only difference being: Replace the mixing time in step two with 9 minutes; The plant fiber molded product prepared in Comparative Example 5 has a full and complete structure; there is slurry with an area greater than 100 mm2, three through cracks, the energy consumption per ton of product is 4480 kWh, and the compressive strength is 0.7 MPa.

[0058] Example 9 The preparation process is basically the same as in Example 1, with the only difference being: Replace the mixing time in step two with 60 minutes; The plant fiber molded products prepared in this embodiment have a full and complete structure, with no obvious slurry or cracks on the material surface. The energy consumption per ton of molded products is 4530 kWh, and the compressive strength is 3.2 MPa.

[0059] Example 10 The preparation process is basically the same as in Example 1, with the only difference being: Replace the extrusion pressure in step three, i.e. the injection pressure, with 0.1 MPa; The plant fiber molded product prepared in this embodiment has a basically intact structure, with no obvious slurry or cracks on the material surface. The energy consumption per ton of product is 4490 kWh, and the compressive strength is 2.2 MPa.

[0060] Example 11 The preparation process is basically the same as in Example 1, with the only difference being: Replace the extrusion pressure in step three, i.e. the injection pressure, with 2MPa; The plant fiber molded product prepared in this embodiment has a basically intact structure, with a small amount of missing material on the sample surface. There is no obvious slurry or cracking on the material surface. The energy consumption per ton of product is 4520 kWh, and the compressive strength is 3.9 MPa.

[0061] Comparative Example 6 The preparation process is basically the same as in Example 1, with the only difference being: Replace the extrusion pressure in step three, i.e. the injection pressure, with 0.09 MPa; The plant fiber molded product prepared in Comparative Example 6 had a basically intact structure, with a small amount of missing material on the sample surface. The material surface showed no obvious slurry buildup or cracking. The energy consumption per ton of product molded was 4480 kWh, and the compressive strength was 1.7 MPa. Comparison of Comparative Example 6 with Example 1 shows that products obtained with an injection pressure less than 0.1 MPa have a small amount of missing material on their surface, which does not meet industry standards.

[0062] The product parameters obtained through the above embodiments and comparative examples are shown in Table 1 below: Table 1

[0063] Through the experiments conducted in the above embodiments and comparative examples, it was found that when the mass ratio of rheology-modified plant fiber to rheology-modifying material is 1:0.005 to 0.3, it can ensure that the modified plant fiber molding preform can be continuously extruded through the extrusion equipment while reducing the molding energy consumption of plant fiber molded products. When the mass ratio of plant fiber to rheology-modifying material is too high (e.g., 1:0.004), the viscosity of the plant fiber molding preform will increase, making it impossible to extrude continuously and smoothly, and may even cause blockage or jamming in the extrusion equipment, resulting in equipment shutdown; for example, the plant fiber molded product prepared in Comparative Example 1 has an incomplete structure with large areas of voids. When the mass ratio of plant fiber to rheology-modifying material is too low (e.g., 1:0.4), the drying and molding energy consumption of plant fiber molded products will increase, thereby leading to an increase in carbon emissions.

[0064] Preferably, the mass ratio of plant fiber to rheology modifier is 1:0.005-0.2. In this case, the modified plant fiber molding preform can be continuously and smoothly extruded through an extrusion device, further reducing the molding energy consumption of plant fiber molded products (energy consumption per ton of product ≤8000kWh). More preferably, the mass ratio of plant fiber to rheology modifier is 1:0.005-0.1. In this case, the modified plant fiber molding preform can be continuously and smoothly extruded through an extrusion device, further reducing the molding energy consumption of plant fiber molded products (energy consumption per ton of product ≤6000kWh).

[0065] Experiments revealed that when the mass ratio of rheology-modified plant fiber to binder is 1:0.01 to 0.2, the plant fiber in the molded product is relatively uniformly dispersed, with no blocky slurry with an area greater than 100 square millimeters, no more than one blocky slurry with an area not greater than 100 square millimeters, no through cracks or cracks wider than 3 mm, and no single crack with a length greater than 40 mm. When the mass ratio of rheology-modified plant fiber to binder is too high (such as 1:0.009 in Comparative Example 4), it will cause through cracks or blocky slurry with an area greater than 100 square millimeters in the molded product.

[0066] Preferably, the mass ratio of the rheology-modified plant fiber to the binder is 1:0.05-0.2. In this case, the plant fiber molded product has no blocky slurry with an area greater than 100 square millimeters, no more than one blocky slurry with an area not greater than 100 square millimeters, a cumulative length of linear slurry not greater than 100 millimeters, no penetrating cracks or cracks wider than 3 millimeters, a single crack length not greater than 40 millimeters, and a cumulative crack length not greater than 80 millimeters. More preferably, the mass ratio of the rheology-modified plant fiber to the binder is 1:0.1-0.2. In this case, the surface of the plant fiber molded product is smooth and flat, without obvious slurry or cracking.

[0067] Experiments revealed that when the injection pressure was configured between 0.1 MPa and 2 MPa, the structure remained largely intact, with no material shortages on the sample surface and no obvious slurry buildup or cracking. However, when the extrusion pressure was less than 0.1 MPa, as in Comparative Example 6 where the injection pressure was replaced with 0.09 MPa, a small amount of material shortage appeared on the sample surface, making it impossible to obtain products that met the standards. When the extrusion pressure was greater than 2 MPa, it resulted in increased energy consumption and difficulties in demolding.

[0068] Experiments have shown that, with the continuous optimization of the above-mentioned rheological modification methods, the preparation method of the novel plant fiber molded products of this invention can further reduce the molding energy consumption of plant fiber molded products, saving many cumbersome processes and a large amount of manpower and material resources. At the same time, it can achieve an energy consumption of ≤5000kWh per ton of product. Compared with the traditional wet pressing plant fiber molding method, which consumes about 12000kWh per ton of product, it saves about 7000kWh per ton of product, achieving an energy consumption of only about 40% of the traditional energy consumption. It also eliminates many complicated preparation processes, saving energy, time, and manpower, reducing costs and carbon emissions. At the same time, the novel plant fiber molded products prepared using this method have a smooth and flat surface, without obvious slurry residue or cracking, and have good quality. They can be applied to various plant fiber molded products, such as industrial packaging and high-end packaging.

[0069] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a novel plant fiber molded product, characterized in that, Includes the following steps: Step 1: Crush the plant fibers and use rheological modification materials to modify the crushed plant fibers to obtain modified fibers; The rheological modification includes at least one of chemical crosslinking modification, chemical grafting modification, and physical blending modification; The mass ratio of plant fiber to rheology-modified material is 1 to 0.005 to 0.3; Step 2: The modified fiber is dry-mixed with binder and waterproofing agent to obtain plant fiber molding preform; The modified fiber to binder mass ratio is 1 to 0.01 to 0.2; Step 3: Use an extrusion device to extrude the plant fiber molding preform into a mold to obtain the molded plant fiber preform; Step 4: Demold the plant fiber preform to obtain the plant fiber molded product.

2. The method for preparing the novel plant fiber molded article according to claim 1, characterized in that, In step one: The method for crushing plant fibers includes at least one of dry crushing, hydraulic pulping, and milling; The rheology-modifying material includes a mixture of sodium octenyl succinate starch and maleic anhydride, as well as at least one of montmorillonite, cellulose derivatives, glyoxal, citric acid, silica, glycerol, and water.

3. The method for preparing the novel plant fiber molded article according to claim 1, characterized in that, In step two: The dry mixing method employs at least one of the following mixing equipment: high-speed mixer, planetary mixer, kneader, open mill, twin-screw extruder, and single-screw extruder. The temperature during the dry mixing process is maintained between 25°C and 80°C, and the mixing time is between 10 minutes and 60 minutes.

4. The method for preparing the novel plant fiber molded article according to claim 1, characterized in that, In step two: The form of the plant fiber molding preform is configured as at least one of the following: granules, strips, and clumps.

5. The method for preparing the novel plant fiber molded article according to claim 1, characterized in that, In step three: The extrusion temperature of the extrusion equipment is configured to be from 25°C to 120°C, and the extrusion pressure is configured to be from 0.1 MPa to 2 MPa; During extrusion molding, the die temperature of the extrusion equipment is configured to be between 25°C and 250°C, and the die heating method includes at least one of electric heating, steam heating, infrared heating, hot air heating, and microwave heating.

6. The method for preparing the novel plant fiber molded article according to claim 1, characterized in that, The mass ratio of plant fiber to rheology-modified material is 1:0.005-0.

2.

7. The method for preparing the novel plant fiber molded article according to claim 1, characterized in that, The binder includes at least one of natural latex, cationic modified starch, polyethylene oxide, sodium carboxymethyl cellulose, and gelatin; the mass ratio of the rheology-modified plant fiber to the binder is 1:0.05-0.

2.

8. The method for preparing the novel plant fiber molded article according to claim 1, characterized in that, In step four, after demolding the plant fiber preform, the following steps are also included: The pre-molded plant fiber product is cut to obtain a molded plant fiber product.

9. The novel plant fiber molded article obtained by the preparation method according to any one of claims 1-8 is used in plant fiber molded articles.

10. A novel plant fiber molded product, characterized in that, The novel plant fiber molded article is obtained by the preparation method described in any one of claims 1-8.

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