Wood fiber material surface continuous roller press

Abstract

The invention discloses a continuous roller press for the surface of a wood fiber material, which belongs to the field of wood fiber material processing equipment and comprises a continuous roller press sequentially provided with a surface plastifying device, a gradient plastifying device, a multi-stage progressive rolling compacting device and a cooling shaping device along the advancing direction of the material, the surface plasticizing device is used for coating plasticizers on the upper and lower surfaces of the material and improving the surface plasticizing performance; the gradient plasticizing device is used for carrying out gradient plasticizing and efficient preheating softening on the material; the multi-stage progressive rolling compaction device is used for compressing and shaping stage by stage to realize lossless compaction of cell walls / cavities; and the cooling and shaping device is used for cooling and shaping, inhibiting instantaneous springback and stabilizing the size. The device is suitable for continuous surface processing of wood fiber materials such as wood, bamboo and composite boards, the surface density and the processing consistency can be improved, the problems that traditional intermittent flat plate hot pressing is low in production efficiency and the width of a press is limited are solved, and continuous and large-scale production is achieved.

Description

Technical Field

[0001] This invention belongs to the field of wood fiber material processing equipment, and more specifically, relates to a continuous roller press for wood fiber material surface processing. Background Technology

[0002] As a renewable, recyclable, and carbon-fixing fibrous material, wood holds irreplaceable strategic value in the context of "dual carbon" (carbon dioxide, carbon sequestration, and carbon emissions) and the global process of sustainable development. High-quality natural forest timber, with its excellent mechanical properties and decorative appeal, can partially replace non-renewable petroleum-based composite materials in furniture, construction, and transportation. However, limited by the finite reserves of high-quality natural forest resources and strict logging controls, its supply struggles to meet the continuously growing demand from high-end market applications.

[0003] In contrast, plantation-grown fast-growing timber (such as poplar, fir, eucalyptus, and pine) is abundant and has a rapid turnover, but it generally suffers from low density, insufficient strength and dimensional stability, and susceptibility to moisture absorption and deformation, hindering its high-value solid wood utilization. Wood-based composite materials (such as laminated veneer lumber and plywood) made from fast-growing timber also face problems such as low surface hardness, insufficient wear resistance, and poor moisture resistance, making it difficult to meet the application requirements of high-load and durable scenarios. Therefore, improving the quality and efficiency of low-quality fast-growing timber and promoting its transformation into high-value solid wood is an important path to alleviate the shortage of high-quality timber supply in my country and achieve material substitution and green manufacturing.

[0004] Compression modification technology can effectively improve the apparent density and mechanical properties of wood. Surface compression treatment, in particular, significantly enhances surface hardness, abrasion resistance, and dent resistance while maintaining material utilization, reducing volume loss, and achieving a "lightweight and high-strength" performance combination at a lower density level. Despite the clear effects of this process, large-scale adoption is still hampered by bottlenecks such as complex preparation processes and high energy consumption. The fundamental reason is that the wood cell wall is a multi-scale complex network composed of cellulose, hemicellulose, and lignin, maintained through interactions such as hydrogen bonds, covalent bonds, and van der Waals interactions. This network provides necessary structural support for wood but also limits its thermoplasticization and deformability. Sufficient plasticization and stabilization treatment are necessary to achieve controllable compression and dimensional stability.

[0005] Existing plasticizing strategies mainly include high-temperature steam treatment, chemical treatment agents (such as ionic liquids, deep eutectic solvents, ammonia, and low molecular weight resins), and delignification treatment. While high-temperature steam can improve thermoplasticization behavior, it has a long processing cycle, high energy consumption, and limited improvement on long-term dimensional stability. Most chemical treatment agents have high viscosity and insufficient permeability, often requiring large-volume impregnation tanks for full-section penetration to ensure treatment effectiveness. This results in high reagent consumption, long processing cycles (several hours to several days), complex subsequent curing and cleaning processes, potential environmental emissions, and low overall production efficiency. Delignification treatment for large-sized samples also faces problems such as high reagent consumption, difficult recovery, and low production efficiency. More importantly, the above methods mostly rely on intermittent flatbed hot pressing, making it difficult to achieve continuous processes and integrated equipment. The length and width of the material treated per batch are limited by the press's width and load capacity, making it difficult to meet the needs of long-size continuous and large-scale production, which has become a core constraint on the industrialization of compressed wood.

[0006] In comparison, continuous roll forming offers advantages such as high production efficiency, minimal limitations on material length, and ease of integrating upstream pretreatment and downstream shaping and curing, making it a powerful technological path for achieving continuous compression modification. However, existing roll forming equipment generally suffers from the following pain points: First, plasticizer (or plasticizer) coating relies heavily on manual operation, resulting in poor consistency in coating amount between batches, easily leading to over-plasticization or under-plasticization of the surface, thus affecting subsequent roll forming deformation behavior and molding quality. Second, it lacks closed-loop control capabilities for online monitoring, feedback, and adjustment, making it difficult to accurately control the coating amount, penetration depth, and heating conditions based on fluctuations in working conditions such as sheet type, thickness, moisture content, and surface temperature. Third, insufficient series connection and cycle matching between equipment units make it difficult to achieve seamless connection and integrated operation from surface plasticization, heating softening, roll forming to stable shaping, affecting product consistency and production efficiency. Summary of the Invention

[0007] The main objective of this invention is to provide a continuous roller press for the surface of wood fiber materials to solve the problems mentioned above in the background.

[0008] According to a first aspect of the present invention, a continuous roller press for surface treatment of wood fiber materials is provided, comprising: A surface plasticizing device is used to coat the upper and lower surfaces of a wood fiber material with a plasticizer to improve the plasticizing properties of the wood fiber material. A gradient plasticizing device is used to perform gradient plasticizing and efficient preheating softening on the surface layer of the wood fiber material; A multi-stage progressive roller compaction device is used for step-by-step compression to achieve non-destructive compaction of cell walls / cavities. A cooling and shaping device is used to suppress the instantaneous springback of the roller-pressed and compacted wood fiber material and to achieve shaping. The surface plasticizing device, gradient plasticizing device, multi-stage progressive roller compaction device, and cooling and shaping device are arranged sequentially along the direction of travel of the wood fiber material.

[0009] According to a first aspect embodiment of the present invention, a continuous roller press for surface treatment of wood fiber materials includes a surface plasticizing device comprising a coating unit, an online coating weight monitoring unit, and a closed-loop control system. The coating unit comprises a main coating roller, a metering roller, and a doctor blade. The metering roller is positioned in front of the main coating roller. The amount of plasticizer picked up by the main coating roller can be controlled by adjusting the gap and rotational speed between the metering roller and the main coating roller. The doctor blade is used to control the amount of plasticizer carried by the metering roller. The online coating weight monitoring unit comprises at least two sets of weight sensors, which are located in front of and behind the main coating roller, respectively, for measuring the weight of the wood fiber material before coating and the weight of the plasticizer after coating. The closed-loop control system comprises a programmable logic controller (PLC). The PLC automatically adjusts the rotational speed of the metering roller and the gap between it and the main coating roller according to the signals from the weight sensors to precisely control the coating amount.

[0010] According to the first aspect of the present invention, the continuous roller press for surface coating of wood fiber materials is provided in the coating unit, which is provided with a spraying device disposed above the metering roller for spraying a wood plasticizer.

[0011] According to the first aspect of the present invention, the continuous rolling mill for surface treatment of wood fiber materials is provided, wherein the surface plasticizing device is further provided with a main servo motor, the main servo motor is used to drive the metering roller and the main coating roller, and the programmable logic controller controls the rotational speed of the main servo motor.

[0012] According to a first aspect embodiment of the present invention, the continuous surface pressing machine for wood fiber materials includes a gradient plasticizing device comprising a track, a heating element, a temperature monitor, and a main servo motor. The track is driven by a drive roller connected to the main servo motor. A tension roller providing tension is provided inside the track. The heating element is disposed inside the track and fixedly connected to the frame. The heating element is movably connected to the track. The heating element is at least one of an electric heating plate and an electromagnetic induction coil. The temperature monitor is provided with a thermocouple probe and a second controller. The thermocouple probe is used to monitor the temperature of the track, and the second controller is used to control the heating element of the gradient plasticizing device.

[0013] According to the first aspect of the present invention, the continuous roller press for the surface of wood fiber materials includes a multi-stage progressive roller compaction device comprising a multi-stage roller group unit, heating elements, a temperature monitor, and a main servo motor. The multi-stage roller group unit consists of at least two sets of pressure rollers, each roller group including an upper pressure roller and a lower pressure roller, and the gap between the upper and lower pressure rollers of the first stage to the last stage gradually decreases. The main servo motor is used to drive each stage of the pressure rollers. The heating elements are all disposed inside the upper and lower pressure rollers, and the heating elements are at least one of an electric heating plate and an electromagnetic induction coil. The temperature monitor is provided with a thermocouple probe located inside the upper and lower pressure rollers and a third controller. The thermocouple probe is used to monitor the temperature of each upper and lower pressure roller, and the third controller is used to control the heating elements of the multi-stage progressive roller compaction device. Each stage of the roller group can be independently temperature controlled.

[0014] According to the first aspect of the present invention, the continuous surface roller press for wood fiber materials includes a cooling and shaping device comprising a track, a circulating cooling water pipeline system, a temperature monitor, and a main servo motor. The track is driven by a drive roller connected to the main servo motor. A tension roller providing tension is provided inside the track. The circulating cooling water pipeline system is located inside the track and includes cooling water pipes. The cooling water pipes are fixedly connected to the frame and movably connected to the track. The temperature monitor is equipped with a thermocouple probe and a display for monitoring the temperature of the track.

[0015] According to the first aspect of the present invention, the continuous surface roller press for wood fiber materials is provided with a roller gap control system in the surface plasticizing device, the gradient plasticizing device, the multi-stage progressive roller pressing compaction device, and the cooling and shaping device. The roller gap control system includes a secondary servo motor and a displacement adjusting screw. The secondary servo motor is used to drive the displacement adjusting screw to precisely control the gap between the upper roller and the lower roller.

[0016] One of the above-described technical solutions of the present invention has at least one of the following advantages or beneficial effects: This invention replaces the traditional intermittent flatbed hot pressing process by sequentially incorporating a surface plasticizing device, a gradient plasticizing device, a multi-stage progressive roller compaction device, and a cooling and shaping device. It enables continuous roller pressing of long-length wood fiber materials, avoiding the limitations of press width and load capacity in single-pass processing, significantly improving production efficiency, and making it suitable for large-scale industrial applications. It achieves precise coordination and continuous production of efficient surface plasticizing, roller compaction, and shaping processes for wood fiber materials, significantly improving surface treatment quality and manufacturing efficiency, reducing energy consumption and dosage, and promoting the high-value solid wood utilization and industrialization of low-quality, fast-growing timber. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic diagram of the structure of the continuous roller press for the surface of wood fiber materials in the first embodiment of the present invention; Figure 2 This is a schematic diagram of the surface plasticizing device in the first embodiment of the present invention; Figure 3 This is a schematic diagram of the gradient plasticizing device in the first embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the multi-stage progressive roller compaction device in the first embodiment of the present invention; Figure 5 This is a schematic diagram of the cooling and shaping device in the first embodiment of the present invention; Figure 6 These are microscopic images of the cross-sections of roll-pressed wood and conventionally hot-pressed wood.

[0018] Figure label: 1. Surface plasticizing device; 11. Coating unit; 12. Online coating weight monitoring unit; 13. Closed-loop control system; 14. Main servo motor; 15. Pressure roller gap control system; 111. Main coating roller; 112. Metering roller; 113. Doctor blade; 114. Tray; 115. Spraying device; 121. Weight sensor; 151. Auxiliary servo motor; 152. Displacement adjusting screw; 2. Gradient plasticizing device; 21. Track; 22. Heating element; 23. Temperature monitor; 24. Drive roller; 25. Tension roller; 26. Thermocouple probe; 3. Multi-stage progressive roller compaction device; 31. Multi-stage roller group unit; 311. Upper pressure roller; 312. Lower pressure roller; 4. Cooling and shaping device; 41. Circulating cooling water pipeline system. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" and "second" may explicitly or implicitly include one or more features.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection or a connection that allows communication between the two components; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components, an indirect connection, or an interaction between two components.

[0024] The following disclosure provides many different implementations or examples for different ways of implementing the present invention.

[0025] Reference Figures 1 to 5 As shown, a continuous roller press for surface treatment of wood fiber materials is provided, comprising: Surface plasticizing device 1 is used to coat the upper and lower surfaces of wood fiber material with plasticizer to improve the plasticizing performance of wood fiber material; Gradient plasticizing device 2 is used to perform gradient plasticizing and efficient preheating softening on the surface layer of wood fiber material; Multi-stage progressive roller compaction device 3 is used for step-by-step compression to achieve non-destructive compaction of cell walls / cavities; Cooling and shaping device 4 is used to suppress the instantaneous springback of the roller-pressed and compacted wood fiber material and to achieve shaping; The surface plasticizing device 1, the gradient plasticizing device 2, the multi-stage progressive roller compaction device 3, and the cooling and shaping device 4 are arranged sequentially along the direction of travel of the wood fiber material.

[0026] In some embodiments of the present invention, the surface plasticizing device 1 includes a coating unit 11, an online coating weight monitoring unit 12, and a closed-loop control system 13. The coating unit 11 is provided with a main coating roller 111, a metering roller 112, and a doctor blade 113. The metering roller 112 is located in front of the main coating roller 111. The amount of plasticizer picked up by the main coating roller 111 can be controlled by adjusting the gap and rotation speed between the metering roller 112 and the main coating roller 111. The doctor blade 113 is used to control the amount of plasticizer carried by the metering roller 112. The online coating weight monitoring unit 12 is provided with at least two sets of weight sensors 121. The two weight sensors 121 are located in front of and behind the main coating roller 111, respectively, and are used to measure the weight of the wood fiber material before coating and the weight of the plasticizer after coating, respectively. The closed-loop control system 13 is provided with a programmable logic controller. The programmable logic controller automatically adjusts the rotation speed of the metering roller 112 and the gap between it and the main coating roller 111 according to the signal of the weight sensor 121 to accurately control the coating amount.

[0027] In some embodiments of the present invention, the coating unit 11 is further provided with a spraying device 115, which is disposed above the metering roller 112 and is used to spray plasticizer.

[0028] In some embodiments of the present invention, the surface plasticizing device 1 is further provided with a main servo motor 14, which is used to drive the metering roller 112 and the main coating roller 111, and the programmable logic controller controls the rotation speed of the main servo motor 14.

[0029] In some embodiments of the present invention, the gradient plasticizing device 2 includes a track 21, a heating element 22, a temperature monitor 23, and a main servo motor 14. The track 21 is driven by a drive roller 24 connected to the main servo motor 14. A tension roller 25 for providing tension is provided inside the track 21. The heating element 22 is disposed inside the track 21 and is fixedly connected to the frame. The heating element 22 is movably connected to the track 21. The heating element 22 is at least one of an electric heating plate and an electromagnetic induction coil. The temperature monitor 23 is provided with a thermocouple probe 26 and a second controller. The thermocouple probe 26 is used to monitor the temperature of the track 21, and the second controller is used to control the heating element 22 of the gradient plasticizing device 2.

[0030] In some embodiments of the present invention, the multi-stage progressive roller compaction device 3 includes a multi-stage roller group unit 31, a heating element 22, a temperature monitor 23, and a main servo motor 14. The multi-stage roller group unit 31 consists of at least two sets of pressure rollers. Each roller group includes an upper pressure roller 311 and a lower pressure roller 312, and the gap between the upper pressure roller 311 and the lower pressure roller 312 decreases progressively from the first stage to the last stage. The main servo motor 14 is used to drive each stage of the pressure rollers. The heating element 22 is disposed inside the upper pressure roller 311 and the lower pressure roller 312. The heating element 22 is at least one of an electric heating plate and an electromagnetic induction coil. The temperature monitor 23 is provided with a thermocouple probe 26 located inside the upper pressure roller 311 and the lower pressure roller 312 and a third controller. The thermocouple probe 26 is used to monitor the temperature of each upper pressure roller 311 and the lower pressure roller 312. The third controller is used to control the heating element 22 of the multi-stage progressive roller compaction device 3. Each stage of the roller group can be independently temperature controlled.

[0031] In some embodiments of the present invention, the cooling and shaping device 4 includes a track 21, a circulating cooling water pipeline system 41, a temperature monitor 23, and a main servo motor 14. The track 21 is driven by a drive roller 24 connected to the main servo motor 14. A tension roller 25 providing tension is provided inside the track 21. The circulating cooling water pipeline system 41 is located inside the track 21. The circulating cooling water pipeline system 41 includes cooling water pipes. The cooling water pipes are fixedly connected to the frame and movably connected to the track 21. The temperature monitor 23 is equipped with a thermocouple probe 26 and a display for monitoring the temperature of the track 21.

[0032] In some embodiments of the present invention, the surface plasticizing device 1, the gradient plasticizing device 2, the multi-stage progressive roller compaction device 3, and the cooling and shaping device 4 are all equipped with a roller gap control system 15. The roller gap control system 15 includes a secondary servo motor 151 and a displacement adjusting screw 152. The secondary servo motor 151 is used to drive the displacement adjusting screw 152 to precisely control the gap between the upper and lower rollers. The displacement adjusting screw 152 is installed in the bracket.

[0033] In some embodiments of the present invention, the rotational speed of each main servo motor 14 is controlled by a programmable logic controller, and the wood fiber material moves at a constant linear speed in the continuous roller press.

[0034] In some embodiments of the present invention, the wood fiber materials include poplar, fir, eucalyptus, pine, bamboo, laminated veneer lumber, and plywood, etc.

[0035] In this embodiment, the main servo motor 14, track 21, temperature monitor 23, and tension roller 25 on each device are all separately set components, each used for the corresponding device and playing a corresponding role.

[0036] The technical solution of the present invention will be further illustrated below with examples.

[0037] Example 1 Poplar wood was processed into samples with dimensions of 1500mm (longitudinal) × 150mm (tangential) × 25mm (radial), and an air-dry density of 0.45g / cm³. 3 The equilibrium moisture content is 10-12%. A eutectic solvent composed of menthol and pyruvic acid is sprayed onto the metering roller 112 as a plasticizer. The distance between the doctor blade 113 and the metering roller 112 is set to 0.5 mm, the distance between the metering roller 112 and the main coating roller 111 is 0.1 mm, the distance between the upper and lower main coating rollers is 24.9 mm, and the rotation speed of the main coating roller 111 is 10 rpm.

[0038] Preparation steps: Feeding: The sample is placed on the weight sensor 121 in front of the main coating roller unit, and the control system records the sample mass. Then, it enters the main coating roller area to coat with plasticizer. Finally, the mass is weighed again on the weight sensor after the main coating roller unit, and the coating amount is recorded as 20wt%. Preheating: The coated sample enters the gradient plasticizing zone, the temperature is set to 120℃, and the speed of the drive roller is 10 rpm; Roller pressing: The preheated and plasticized sample enters the multi-stage roller pressing zone. The spacing of the first stage rollers is set to 24 mm and the temperature is 120℃; the spacing of the second stage rollers is set to 22 mm and the temperature is 110℃; the spacing of the third stage rollers is set to 20 mm and the temperature is 100℃; the rotation speed of the first to third stage drive rollers is 10 rpm. Cooling: The rolled sample enters the cooling and shaping zone, and cooling circulating water is circulated in the conveyor belt. The drive roller speed is 10 rpm. Finally, the surface rolled sample is obtained and processed into a 50 mm (longitudinal) × 50 mm (chordal) × 20 mm (radial) test sample to test density, surface hardness, resilience and micromorphology.

[0039] Comparative Example 1 (Intermittent Hot Pressing) Poplar wood was processed into samples with dimensions of 600mm (longitudinal) × 150mm (tangential) × 25mm (radial), and an air-dry density of 0.45g / cm³. 3 The equilibrium moisture content was 10-12%; a eutectic solvent composed of menthol and pyruvic acid (mass ratio 1:1) was sprayed onto the upper and lower surfaces of the sample as a plasticizer, with a coating amount of 20 wt%. Hot pressing step: Preheating: Place the sample into a hot press with upper and lower heated plates at a temperature of 120°C for 60 seconds and a pressure of 0.5 MPa. Compression: Increase the pressure to 4.5 MPa and hot-press for 5 minutes; Cooling: The compressed sample is taken out and placed in a press with a hot plate at 30°C for 5 minutes to cool, thus obtaining surface compressed wood.

[0040] Example 2 The cedar wood was processed into samples with dimensions of 1500mm (longitudinal) × 150mm (tangential) × 25mm (radial), and the air-dry density was 0.37g / cm³. 3 The equilibrium moisture content is 10-12%. A eutectic solvent composed of menthol and pyruvic acid is sprayed onto the metering roller as a plasticizer. The distance between the doctor blade and the metering roller is set to 0.8 mm, the distance between the metering roller and the main coating roller is 0.2 mm, the distance between the upper and lower main coating rollers is 24.9 mm, and the rotation speed of the main coating roller is 5 rpm.

[0041] Rolling process: Feeding: The sample is placed on the weight sensor in front of the main coating roller unit, and the control system records the sample mass. Then, it enters the main coating roller area to coat with plasticizer. Finally, the mass is weighed again on the weight sensor after the main coating roller unit, and the coating amount is recorded as 28 wt%. Preheating: The coated sample enters the gradient plasticizing zone, the temperature is set to 110℃, and the speed of the drive roller is 5 rpm; Roller pressing: The preheated and plasticized sample enters the multi-stage roller pressing zone. The spacing of the first stage rollers is set to 24 mm and the temperature is 110℃; the spacing of the second stage rollers is set to 22 mm and the temperature is 100℃; the spacing of the third stage rollers is set to 20 mm and the temperature is 100℃; the rotation speed of the first to third stage drive rollers is 5 rpm. Cooling: The rolled sample enters the cooling and shaping zone, and cooling circulating water is introduced into the track. The drive roller speed is 5 rpm. Finally, the surface rolled sample is obtained and processed into a 50 mm (longitudinal) × 50 mm (chordal) × 20 mm (radial) test sample to test density, surface hardness, resilience and micromorphology.

[0042] Comparative Example 2 (Intermittent Hot Pressing) The cedar wood was processed into samples with dimensions of 600mm (longitudinal) × 150mm (tangential) × 25mm (radial), and the air-dry density was 0.37g / cm³. 3 The equilibrium moisture content was 10-12%. A eutectic solvent composed of menthol and pyruvic acid (mass ratio 1:1) was sprayed onto the upper and lower surfaces of the sample as a plasticizer, with a coating amount of 28 wt%.

[0043] Hot pressing step: Preheating: Place the sample into a hot press with upper and lower hot plates at a temperature of 110°C for 120 seconds at a pressure of 0.5 MPa. Compression: Increase the pressure to 4.5 MPa and hot-press for 5 minutes; Cooling: The compressed sample is taken out and placed in a press with a hot plate at 30°C for 5 minutes to cool, thus obtaining surface compressed wood.

[0044] To better illustrate the present invention, the compressed wood obtained from each embodiment was tested below. The density of the samples was tested according to GB / T1927.5-2021; the surface hardness of the samples was tested according to GB / T1927.19-2021; the bending strength of the samples was measured according to GB / T1927.9-2021; the bending modulus of elasticity of the samples was measured according to GB / T1927.10-2021; the moisture absorption resilience of the samples was measured using industry-standard testing methods; the cross-sectional micromorphology of the compressed samples was characterized using a field emission scanning electron microscope (SU8010, HITACHI, Japan). Comparisons were made with comparative examples. The performance results are shown in Table 1 and... Figure 6 , Figure 6 'a' represents roll-pressed wood. Figure 6 b represents traditional hot-pressed wood. Figure 6 a is Example 1. Figure 6 b is comparative example 1.

[0045] Table 1 Performance Comparison Analysis Test metrics Example 1 Comparative Example 1 Example 2 Comparative Example 2 <![CDATA[Density (g / cm 3 ).]]> 0.56 0.55 0.48 0.47 Surface hardness (kN) 4.02 3.52 2.94 2.25 Flexural strength (MPa) 106.5 98.6 88.4 82.6 Flexural modulus of elasticity (GPa) 9.50 8.65 7.82 7.43 Moisture absorption and resilience (%) 2.21 8.63 2.90 7.56 The experimental results above show that the density of the compressed wood prepared in Examples 1 and 2 is comparable to that of Comparative Examples 1 and 2, but the surface hardness, bending strength, and elastic modulus are superior to those of Comparative Examples 1 and 2, indicating that the modification effect of Examples 1 and 2 is better. Combined with microscopic morphology characterization analysis, it was found that no significant damage was observed in the cell wall structure of the samples prepared in the examples, while slight damage to the cell wall structure was observed in the comparative examples. This is also a key factor leading to the reduction in its mechanical properties. It is worth noting that Examples 1 and 2 used continuous rolling technology, which has the advantage of enabling continuous rolling of long pieces of wood, significantly improving production efficiency compared to intermittent hot pressing.

[0046] The above is a further detailed description of the present invention and should not be considered as a limitation on the specific implementation of the present invention. For those skilled in the art, simple deductions or substitutions without departing from the concept of the present invention are all within the protection scope of the present invention.

Claims

1. A wood fiber material surface continuous roll press, characterized by, include: Surface plasticizing device (1), the surface plasticizing device (1) is used to coat the upper and lower surfaces of wood fiber material with plasticizer to improve the plasticizing performance of wood fiber material; Gradient plasticizing device (2), the gradient plasticizing device (2) is used to perform gradient plasticizing and efficient preheating softening on the surface layer of the wood fiber material; Multi-stage progressive roller compaction device (3) is used for progressive compression to achieve non-destructive compaction of cell walls / cavities; Cooling and shaping device (4), the cooling and shaping device (4) is used to suppress the instantaneous rebound of the roller-pressed and compacted wood fiber material and to achieve shaping; The surface plasticizing device (1), gradient plasticizing device (2), multi-stage progressive roller compaction device (3) and cooling and shaping device (4) are arranged sequentially along the direction of travel of the wood fiber material.

2. The wood fiber material surface continuous lamination press according to claim 1, characterized in that, The surface plasticizing device (1) includes a coating unit (11), an online coating weight monitoring unit (12), and a closed-loop control system (13). The coating unit (11) is equipped with a main coating roller (111), a metering roller (112), and a doctor blade (113). The metering roller (112) is located in front of the main coating roller (111). By adjusting the gap and rotation speed between the metering roller (112) and the main coating roller (111), the amount of plasticizer picked up by the main coating roller (111) can be controlled. The doctor blade (113) is used to control the amount of plasticizer picked up by the metering roller (112). The online coating weight monitoring unit (12) is equipped with at least two sets of weight sensors (121). The two weight sensors (121) are located in front of and behind the main coating roller (111) respectively, and are used to measure the weight of wood fiber material before coating and the weight of plasticizer after coating. The closed-loop control system (13) is equipped with a programmable logic controller. The programmable logic controller automatically adjusts the rotation speed of the metering roller (112) and the gap between it and the main coating roller (111) according to the signal of the weight sensor (121) in order to accurately control the coating amount.

3. The wood fiber material surface continuous lamination press according to claim 2, characterized in that, The coating unit (11) is also provided with a spraying device (115), which is located above the metering roller (112) and is used to spray plasticizer.

4. The continuous roller press for surface treatment of wood fiber materials according to claim 2, characterized in that, The surface plasticizing device (1) is also provided with a main servo motor (14), which is used to drive the metering roller (112) and the main coating roller (111), and the programmable logic controller controls the rotation speed of the main servo motor (14).

5. The continuous roller press for surface treatment of wood fiber materials according to claim 1, characterized in that, The gradient plasticizing device (2) includes a track (21), a heating element (22), a temperature monitor (23), and a main servo motor (14). The track (21) is driven by a drive roller (24) connected to the main servo motor (14). A tension roller (25) is provided inside the track (21) to provide tension. The heating element (22) is located inside the track (21) and is fixedly connected to the frame. The heating element (22) is movably connected to the track (21). The heating element (22) is at least one of an electric heating plate and an electromagnetic induction coil. The temperature monitor (23) is provided with a thermocouple probe (26) and a second controller. The thermocouple probe (26) is used to monitor the temperature of the track (21), and the second controller is used to control the heating element (22) of the gradient plasticizing device (2).

6. The continuous roller press for surface treatment of wood fiber materials according to claim 1, characterized in that, The multi-stage progressive roller compaction device (3) includes a multi-stage roller group unit (31), a heating element (22), a temperature monitor (23), and a main servo motor (14). The multi-stage roller group unit (31) consists of at least two sets of pressure rollers. Each roller group includes an upper pressure roller (311) and a lower pressure roller (312). The gap between the upper pressure roller (311) and the lower pressure roller (312) decreases progressively from the first stage to the last stage. The main servo motor (14) is used to drive each stage of the pressure rollers. The heating element (22) is installed on the upper pressure roller. The heating element (22) is at least one of an electric heating plate and an electromagnetic induction coil. The temperature monitor (23) is provided with a thermocouple probe (26) and a third controller located inside the upper pressure roller (311) and the lower pressure roller (312). The thermocouple probe (26) is used to monitor the temperature of each upper pressure roller (311) and lower pressure roller (312). The third controller is used to control the heating element (22) of the multi-stage progressive roller compaction device (3). Each roller group can be independently temperature controlled.

7. The continuous roller press for surface treatment of wood fiber materials according to claim 1, characterized in that, The cooling and shaping device (4) includes a track (21), a circulating cooling water pipeline system (41), a temperature monitor (23), and a main servo motor (14). The track (21) is driven by a drive roller (24) connected to the main servo motor (14). A tension roller (25) is provided inside the track (21) to provide tension. The circulating cooling water pipeline system (41) is located inside the track (21). The circulating cooling water pipeline system (41) includes a cooling water pipeline. The cooling water pipeline is fixedly connected to the frame and movably connected to the track (21). The temperature monitor (23) is equipped with a thermocouple probe (26) and a display for monitoring the temperature of the track (21).

8. The continuous roller press for surface treatment of wood fiber materials according to any one of claims 1 to 7, characterized in that, The surface plasticizing device (1), gradient plasticizing device (2), multi-stage progressive roller compaction device (3), and cooling and shaping device (4) are all equipped with a roller gap control system (15). The roller gap control system (15) includes a secondary servo motor (151) and a displacement adjusting screw (152). The secondary servo motor (151) is used to drive the displacement adjusting screw (152) to precisely control the gap between the upper and lower rollers.

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