A method and device for enhancing and modifying the cell wall of fast-growing wood veneer

Abstract

The present invention relates to the technical field of fast-growing wood quality improvement, enhancement and modification technology, and discloses a fast-growing wood veneer cell wall enhancement and modification method and device, the treated surface of the veneer is placed above the liquid surface of the impregnation liquid, and is characterized in that the moisture content of the veneer is 3-20%, and the other surface of the veneer is a pressure surface, when the pressing plate contacts the pressure surface, the liquid surface of the impregnation liquid, the wall surface of the container for canning the impregnation liquid, and the air pressure in the space formed by the pressing plate are in a stable state, and then the pressing plate is pressurized to make the pressure surface receive uniform pressure on its width. The processing time is shorter, the total production cycle is shorter, and the prepared veneer has a higher surface hardness and a larger surface contact angle; the impregnation amount is smaller, which can reduce the processing cost to a certain extent; the required compression amount is smaller, and it has a higher material volume utilization rate.

Description

Technical Field

[0001] The present invention relates to the technical field of fast-growing wood quality improvement, enhancement and modification technology, and more specifically, to a fast-growing wood veneer cell wall enhancement and modification method; the present invention also relates to a device suitable for implementing the fast-growing wood veneer cell wall enhancement and modification method. Background Art

[0002] In order to alleviate the current situation of tight hardwood resources, my country vigorously advocates the use of artificial fast-growing forest wood to replace hardwood. However, the defects of fast-growing wood such as low mechanical strength and poor dimensional stability limit its application scope and use value. In the prior art, impregnation treatment and densification compression treatment are chemical modification and physical modification treatment methods for fast-growing wood respectively, and there are also reports on impregnation-compression combined treatment methods.

[0003] Among the various means of impregnation treatment, vacuum impregnation is the best. Common implementation methods include the Chinese invention patent application with publication number CN106881237A and titled "Vacuum hydraulic impregnation device and impregnation method", which records a vacuum impregnation device including a paint storage tank, a paint impregnation tank, a vacuum unit, an external pressurization component, an emptying component and an internal circulation component, as well as a vacuum impregnation method including vacuum dehumidification, vacuum paint impregnation, hydraulic impregnation, dripping paint, and removing workpieces. Vacuum impregnation treatment can inject an impregnation liquid with a specific function into the wood so that the wood has this function, but the impregnation liquid needs to meet a certain impregnation depth in order for the wood to obtain this function. The greater the impregnation depth, the higher the vacuum degree required and the longer the impregnation time.

[0004] Among the various means of densification and compression treatment, the layered compression method is the best. Common implementation methods include the Chinese invention patent application with publication number CN107263657A and the name "Compression layer thickness control method for layered compression of wood", which records a technical solution including soaking, high temperature preheating at 70 to 250°C, pressurized compression, heat preservation, cooling, and opening the press to obtain layered compressed wood. Layered compression treatment can improve the density and mechanical properties of a specific thickness layer of fast-growing wood, but because the treatment is carried out under high temperature conditions and the wood is squeezed by pressure, the increase in wood density is achieved by squeezing to reduce the cell gap, which is often accompanied by the destruction of the cell structure and the damage of the cell wall. At the same time, a relatively large amount of compression is required to be reflected in the improvement of mechanical properties on a macro scale, so there is a problem of waste of wood volume.

[0005] The method of combined impregnation-compression treatment combines the advantages of both, with the purpose of obtaining a functional high-density fast-growing material. At the same time, the impregnation treatment can increase the cell wall of the fast-growing material to avoid damage to the cell wall during the compression process, so as to achieve the purpose of macroscopic and microscopic synergistic improvement of the mechanical properties of the material. Common implementation methods include the Chinese invention patent application with publication number CN102990759A and the name "Impregnated Compressed Laminated Flooring and Its Manufacturing Method", which records the technical solution of first impregnating the dried wood and then compressing the impregnated wood. However, if the impregnated wood is dried and then compressed, the loss of the agent in the drying and compression process in three different devices is inevitable; if the wood is not dried after impregnation and is directly compressed, it is difficult to be compressed because the impregnated thickness layer is in a saturated state. Although the above application provides a solution for incomplete drying, the effect is not good in actual operation. The incomplete drying and compression process still has the problem of agent loss in three different devices. And from the results, it has not reached a level better than the combination of the two.

[0006] In summary, the prior art lacks an impregnation-compression combined treatment method that can reduce the impregnation amount and compression amount and avoid the waste of impregnation liquid. Summary of the invention

[0007] The present application provides a method and device for enhancing and modifying the cell wall of a fast-growing material veneer, which can reduce the amount of impregnation and compression and avoid waste of impregnation liquid.

[0008] In the first aspect of the present application, a method for enhancing and modifying the cell wall of a fast-growing timber veneer is provided, wherein a treated surface of the veneer is placed above the liquid surface of an impregnating liquid, the moisture content of the veneer is 3-20%, and the other surface of the veneer is a pressure surface. When a pressing plate contacts the pressure surface, the liquid surface of the impregnating liquid, the wall surface of a container for containing the impregnating liquid, and the air pressure in the space formed by the pressing plate are in a stable state, and then the pressing plate is pressurized so that the pressure surface is subjected to uniform pressure over its width.

[0009] In some embodiments, the thickness of the veneer is not less than 2 mm, and the treated surface is the cut back side of the wood.

[0010] In some embodiments, the solution temperature of the impregnating solution is 60-120° C., and the pressure on the pressure-bearing surface is 4-12 MPa.

[0011] In some embodiments, after the pressing plate enters the container, the liquid level of the impregnating liquid, the wall of the container for filling the impregnating liquid, and the air pressure in the space formed by the pressing plate are maintained by allowing the impregnating liquid to leave the container; when the pressing plate contacts the pressure surface, the container is in a closed state.

[0012] In some embodiments, the modification method includes a first impregnation liquid pressure impregnation process and a second impregnation liquid pressure impregnation process;

[0013] The first impregnation liquid pressure impregnation process is to place the single board in a manner that the treated surface floats on the liquid surface of the first impregnation liquid, the temperature of the first impregnation liquid is 60-100° C., and then apply pressure to the pressure surface;

[0014] The second impregnation liquid pressure impregnation process is to replace the first impregnation liquid with a second impregnation liquid having a temperature of 80-120° C., and then apply pressure to the pressure-bearing surface.

[0015] In some embodiments, the pressurization time of the pressure impregnation process with the first impregnation liquid is 30 to 40 minutes, and the pressurization time of the pressure impregnation process with the second impregnation liquid is 25 to 35 minutes.

[0016] In some embodiments, the time taken to complete the process from placing the single board to the pressing plate contacting the pressure surface of the single board is no more than 3 minutes.

[0017] In some embodiments, at least the treated surface of the veneer is pre-treated to remove extractables.

[0018] In the second aspect of the present application, a device for enhancing and modifying the cell wall of a fast-growing material veneer is provided, comprising a container with an opening, a pressing plate whose edges cooperate with the wall of the container, and an impregnation liquid inlet and an impregnation liquid outlet arranged on the wall of the container, wherein the container is capable of filling the impregnation liquid, the bottom plate of the container is a hot plate connected to an external heat source, the pressing plate is a cold plate connected to an external pressure source, the pressing plate can pressurize toward the bottom plate or relieve pressure away from the bottom plate, and the impregnation liquid inlet and the impregnation liquid outlet are respectively connected to a reagent pool and a reagent recovery pool through pipelines.

[0019] In some embodiments, the impregnation liquid inlet is connected to the first reagent pool and the second reagent pool through the first inlet pipeline and the second inlet pipeline, respectively, and the impregnation liquid outlet is connected to the first reagent recovery pool and the second reagent recovery pool through the first outlet pipeline and the second outlet pipeline, respectively.

[0020] In some embodiments, after the pressing plate enters the interior of the container, the edges of the pressing plate form a seal with the wall of the container.

[0021] Different from the step-by-step preparation method, the technical solution of the present invention has almost no impregnation liquid entering the veneer before the pressure is applied by the pressing plate. Therefore, it can be considered that the impregnation of the impregnation liquid and the compression of the veneer are carried out simultaneously. In other words, the pressure applied by the pressing plate compresses the treated surface of the veneer. In order to provide compression space for the compression of the wood, the impregnation liquid that already exists in a certain thickness layer of the treated surface is forced to migrate inward (i.e., toward the compressed surface). Therefore, the method and device of the present invention can simultaneously complete the impregnation and densification compression processes. Therefore, the cell wall enhancement and modification method of fast-growing wood veneer of the present invention has at least the following advantages:

[0022] 1. Impregnation and compression are completed in one processing step, so the processing time is shorter; and there is no need to migrate materials between different processing equipment, so the overall production cycle is shorter.

[0023] 2. The treatment effect is better than that of the step-by-step method, and the prepared single board has higher surface hardness (strength) and larger surface contact angle (hydrophobicity).

[0024] 3. The impregnation volume is smaller, and there is no loss of impregnation liquid during the treatment process, so the treatment cost can be reduced to a certain extent; the required compression volume is smaller, so it has a higher material volume utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0026] Figure 1 This is a schematic structural diagram of the fast-growing material veneer cell wall enhancement and modification device of Example 1 of the present application.

[0027] Figure 2 This is a schematic diagram of the implementation method of the fast-growing wood veneer cell wall enhancement and modification method of Example 2 of the present application.

[0028] In the figure: 100, container, 200, pressing plate, 300, single plate, 110, impregnation liquid inlet, 120, impregnation liquid outlet, 130, bottom plate, 111, first inlet pipeline, 112, second inlet pipeline, 121, first outlet pipeline, 122, second outlet pipeline, 310, processing surface, 320, pressure surface. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0030] Example 1

[0031] refer to Figure 1 The device for enhancing and modifying the cell wall of a fast-growing material veneer shown in the figure comprises a container 100 with an opening, a pressing plate 200 , and an impregnation liquid inlet 110 and an impregnation liquid outlet 120 arranged on the wall surface of the container 100 .

[0032] The container 100 is a metal rectangular impregnation tank capable of canning the impregnation liquid, and includes a bottom plate 130 and four walls. Preferably, the bottom plate 130 is a separate plate independent of the wall. In this embodiment, the bottom plate 130 is a hot plate connected to an external heat source. For example, the bottom plate 130 is a hot press plate, and the external heat source is high-temperature hydraulic oil, which flows into the bottom plate 130 and provides the bottom plate 130 with a high temperature and controls the real-time temperature of the bottom plate 130. The bottom plate 130 is connected to the wall by welding or other sealed connection methods to enclose the canning space of the container 100. The wall used is preferably a metal plate with a heat preservation function.

[0033] The impregnation liquid inlet 110 and the impregnation liquid outlet 120 are respectively connected to the reagent pool and the reagent recovery pool through pipelines, hydraulic pumps, flow sensors, etc. Therefore, the impregnation liquid can enter the container 100 through the impregnation liquid inlet 110 and leave through the impregnation liquid outlet 120. In particular, the impregnation liquid outlet 120 is controlled by a pressure valve, and the impregnation liquid outlet 120 is opened when the liquid pressure at the impregnation liquid outlet 120 reaches a threshold. In some embodiments, the reagent pool and the reagent recovery pool can be the same container, that is, the impregnation liquid enters the container 100 from the reagent pool through the impregnation liquid inlet 110, and returns to the reagent pool through the impregnation liquid outlet 120, so as to facilitate the recycling of the impregnation liquid.

[0034] The impregnation liquid inlet 110 can be connected to a reagent pool through a pipeline, and the impregnation liquid outlet 120 can be connected to a reagent recovery pool through a pipeline. The impregnation liquid inlet 110 can also be connected to the first reagent pool and the second reagent pool through the first inlet pipeline 111 and the second inlet pipeline 112, respectively, and the impregnation liquid outlet 120 can also be connected to the first reagent recovery pool and the second reagent recovery pool through the first outlet pipeline 121 and the second outlet pipeline 122, respectively. Of course, the first reagent pool and the first reagent recovery pool can be the same container, and the second reagent pool and the second reagent recovery pool can be the same container.

[0035] The pressing plate 200 is a cold plate connected to an external pressure source. For example, the pressing plate 200 is arranged above the bottom plate 130 in parallel and can move toward (downward) or away from (upward) the bottom plate 130 by the drive of the hydraulic cylinder. However, the pressing plate 200 is not connected to any heat source, or the pressing plate 200 is connected to a cold water source to ensure that the pressing plate 200 is always at a relatively low temperature, such as room temperature. The edges of the pressing plate 200 are matched with the wall surface of the container 100. Specifically, when the pressing plate 200 enters the container 100, the edges of the pressing plate 200 are sealed with the wall surface of the container 100. That is, when the pressing plate 200 enters the container 100, the container 100 is in a sealed state when the immersion liquid inlet 110 and the immersion liquid outlet 120 are closed. The sealing cooperation between the edges of the pressing plate 200 and the wall surface of the container 100 can be achieved by sealing the contact surface between the two by lubricating liquid or lubricating oil, or by other existing technical means. In order to make the downward movement of the pressing plate 200 more stable, the pressing plate 200 is provided with guide blocks on the four edges thereof, and the inner wall of the container 100 is provided with guide grooves corresponding to the positions of the guide blocks. Similarly, the contact surfaces of the guide blocks and the guide grooves are filled with lubricating liquid or lubricating oil.

[0036] Embodiments 2 to 5

[0037] refer to Figure 2 As shown, this embodiment provides a method for enhancing and modifying the cell wall of a fast-growing material veneer. The thickness of the treated veneer 300 is not less than 2 mm, preferably 2 to 20 mm, and the width is 1200 mm×150 mm for example, with a moisture content of 3 to 20%. The impregnation liquid used is a nano-silicon solution.

[0038] First, hot oil is introduced into the bottom plate 130 to make the bottom plate 130 have a temperature of 60-120°C. The immersion liquid enters the container 100 through the immersion liquid inlet 110. After reaching the set liquid level, the immersion liquid inlet 110 is closed. The temperature of the immersion liquid is observed by a temperature sensor installed on the wall of the container 100 or other means until the temperature is constant. Generally, the temperature is 1-3°C lower than the temperature of the bottom plate 130.

[0039] Then, the veneer 300 is placed with the processed surface 310 facing the liquid surface of the immersion liquid. That is, if the veneer 300 is prepared by peeling or slicing, the cut back side refers to the peeled back side or the sliced ​​back side, and this side is used as the processed surface 310. If the veneer 300 is prepared by sawing, the peeled surface is preferably used as the processed surface 310. Depending on the thickness and moisture content of the veneer 300, the veneer 300 may float on the liquid surface of the immersion liquid, or may be partially immersed in the immersion liquid.

[0040] Then, the pressing plate 200 is driven to press down. Since the container 100 will be in a sealed state after the pressing plate 200 enters the container 100, the pressing plate 200 will force the pressure valve controlling the outlet 120 of the impregnating liquid to open while moving down along the wall of the container 100, so that the liquid level of the impregnating liquid, the wall of the container for filling the impregnating liquid, and the air pressure in the space formed by the pressing plate are in a stable state until the pressing plate 200 contacts the pressure surface 320 of the single board 300. In particular, the time from the placement of the single board 300 to the pressing plate 200 contacting the pressure surface 320 of the single board 300 does not exceed 3 minutes, and theoretically, this time should be shortened as much as possible.

[0041] Then, the pressure valve is in a normally closed state, and the pressing plate 200 is driven to pressurize one side of the bottom plate 130, with a pressure of 4 to 12 MPa, and the pressurization time is 30 to 40 minutes. The width of the pressing plate 200 is larger than the width of the single board 300, so the pressure applied by the pressing plate 200 on the pressure surface is uniform everywhere on the width of the pressure surface. At this time, the liquid surface of the impregnating liquid is equivalent to the lower pressing plate with a certain temperature, which plays the role of a hot plate, and the pressing plate 200 acts as a cold plate to apply pressure, thereby being able to replace the hot plate-cold plate single-sided hot pressing and densification treatment system to achieve hot pressing and densification treatment of the treatment surface 310. The liquid surface of the impregnating liquid that replaces the hot plate simultaneously penetrates the nano-silicon solution into the single board 300 under pressure. The nano-silicon solution entering the single board 300 can be deposited in the cell cavity or attached to the cell wall, thereby strengthening the cell wall.

[0042] Finally, the pressing plate 200 moves away from the bottom plate 130 to release the pressure, and the veneer 300 is taken out with or without draining the impregnation liquid. If necessary, the veneer 300 is dried in any form of the prior art to a moisture content of 10-12%.

[0043] The process parameters of the fast-growing wood veneer cell wall enhancement and modification methods of Examples 2 to 5 are shown in Table 1.

[0044] Table 1. Process parameters of the cell wall enhancement modification method for fast-growing wood veneer of Examples 2 to 5

[0045] Example Example 2 Example 3 Example 4 Example 5 veneer Poplar Rotary Cut Veneer Fir sliced ​​veneer Eucalyptus sawn veneer Poplar sawn veneer Thickness of single board (mm) 2 10 16 20 Initial moisture content (%) 3～5 7～10 12～15 17～20 Bottom plate temperature (℃) 65±2 75±2 95±2 115±2 Platen pressure (MPa) 11.5～12 8.5～9 6～6.5 4～4.5 Pressurization time (min) 30 33 36 40

[0046] Embodiments 6 to 9

[0047] The difference between Examples 6 to 9 and Examples 2 to 5 is that the treated surface 310 of the single board 300 is pre-treated to remove the extracts by a supercritical CO2 fluid treatment method.

[0048] Embodiments 10 to 13

[0049] This embodiment provides a method for enhancing and modifying the cell wall of a fast-growing material veneer, including a first impregnation liquid pressure impregnation process and a second impregnation liquid pressure impregnation process. The treated veneer 300 has a thickness of not less than 2 mm, preferably 2 to 20 mm, a width of 1200 mm×150 mm, and a moisture content of 3 to 20%; the impregnation liquids used include two types, the first impregnation liquid is a calcium chloride solution (CaCl2), and the second impregnation liquid is an ammonium bicarbonate solution ((NH4)2CO3).

[0050] The implementation method of the first impregnation liquid pressure impregnation process is:

[0051] First, hot oil is introduced into the bottom plate 130 to make the bottom plate 130 have a temperature of 60-100° C. The first immersion liquid enters the container 100 through the first inlet pipe 111. When the immersion liquid reaches the set liquid level, the immersion liquid inlet 110 is closed to keep the temperature of the first immersion liquid constant. The second inlet pipe 112 is always closed.

[0052] Then, the single board 300 is placed on the liquid surface of the first immersion liquid.

[0053] Then, the pressing plate 200 is driven to press down. Since the container 100 will be in a sealed state after the pressing plate 200 enters the container 100, the pressing plate 200 will force the pressure valve controlling the outlet 120 of the impregnating liquid to open while moving downward along the wall of the container 100, and part of the first impregnating liquid flows out through the first outlet pipeline 121, so that the liquid level of the impregnating liquid, the wall of the container for filling the impregnating liquid, and the air pressure in the space formed by the pressing plate are in a stable state until the pressing plate 200 contacts the pressure surface 320 of the single board 300. The second outlet pipeline 122 is normally closed.

[0054] Then, the pressure valve is in a normally closed state, and the pressing plate 200 is driven to pressurize the side of the bottom plate 130 at a pressure of 4 to 12 MPa for 15 to 20 minutes. The liquid surface of the impregnation liquid that replaces the hot plate simultaneously penetrates the first impregnation liquid into the single board 300 under pressure. Compared with the nano-silicon solution, the first impregnation liquid can enter the single board 300 more smoothly.

[0055] Finally, the pressing plate 200 moves away from one side of the bottom plate 130 to release the pressure, and the first impregnation liquid is discharged through the first outlet pipe 121 to take out the single board 300.

[0056] The implementation method of the second impregnation liquid pressure impregnation process is:

[0057] First, the bottom plate 130 is set to have a temperature of 80-120° C., the second immersion liquid enters the container 100 through the second inlet pipe 112, and the immersion liquid inlet 110 is closed after reaching the set liquid level, and the temperature of the second immersion liquid is kept constant. The first inlet pipe 111 is always closed.

[0058] Then, the single board 300 is put in again and placed on the liquid surface of the second immersion liquid.

[0059] Then, the pressing plate 200 is driven downward again. Since the container 100 will be in a sealed state after the pressing plate 200 enters the container 100, the pressing plate 200 will force the pressure valve controlling the outlet 120 of the impregnating liquid to open while moving downward along the wall of the container 100, and part of the second impregnating liquid flows out through the second outlet pipeline 122, so that the liquid level of the impregnating liquid, the wall of the container for filling the impregnating liquid, and the air pressure in the space formed by the pressing plate are in a stable state until the pressing plate 200 contacts the pressure surface 320 of the single board 300. The first outlet pipeline 121 is normally closed.

[0060] Then, the pressure valve is in a normally closed state, and the pressing plate 200 is driven to pressurize the side of the bottom plate 130 at a pressure of 4 to 12 MPa for 10 to 15 minutes. The liquid surface of the impregnation liquid that replaces the hot plate simultaneously penetrates the second impregnation liquid into the single board 300 under pressure. The second impregnation liquid that enters the single board 300 can react with the first impregnation liquid to generate CaCO3 that can be deposited in the cell cavity or attached to the cell wall, thereby strengthening the cell wall.

[0061] Finally, the pressing plate 200 moves away from the bottom plate 130 to release the pressure, and the veneer 300 is taken out with or without draining the impregnation liquid. If necessary, the veneer 300 is dried in any form of the prior art to a moisture content of 10-12%.

[0062] The process parameters of the fast-growing wood veneer cell wall enhancement and modification methods of Examples 10 to 13 are shown in Table 2.

[0063] Table 2. Process parameters of the cell wall enhancement modification method for fast-growing wood veneer of Examples 10 to 13

[0064]

[0065] Embodiments 14 to 17

[0066] The difference between Examples 14 to 17 and Examples 10 to 13 is that the treated surface 310 of the single board 300 is pre-treated to remove the extracts by a supercritical CO2 fluid treatment method.

[0067] The process parameters of the cell wall enhancement modification method of the fast-growing wood veneer of the control groups 1 to 4 are shown in Table 3. The control groups 1 to 4 adopt the means of the prior art, for example, firstly, the veneer is impregnated by the vacuum impregnation method, the impregnation liquid is a nano silicon solution, and the impregnation depth is 2 mm; then the moisture content of the impregnation layer of the veneer is dried to 40-50%; and then the densification treatment is carried out by the hot plate compression method, the compression layer thickness is 1.0 mm, and the actual compression amount is 1.0 mm.

[0068] Table 3. Process parameters of cell wall enhancement modification method for fast-growing wood veneer in control groups 1 to 4

[0069] Example Control group 1 Control group 2 Control group 3 Control group 4 veneer Poplar peeled veneer Fir sliced ​​veneer Eucalyptus sawn veneer Poplar sawn veneer Thickness of single board (mm) 2 10 16 20 Initial moisture content (%) 3～5 7～10 12～15 17～20

[0070] The physical and chemical performance parameters of the modified veneers prepared by the fast-growing wood veneer cell wall enhancement modification method of Examples 2 to 17 are shown in Table 3.

[0071] Table 3. Physical and chemical performance parameters of the modified veneers of Examples 2 to 17

[0072]

[0073] Under the condition of the same compression amount or a smaller compression amount, the technical solution of the present invention can obtain a thicker compressed layer because impregnation and compression occur simultaneously. The pressure of the pressing plate provides the impregnation pressure of the impregnation liquid while providing compression space for further densification and forming a new driving force for the penetration of the impregnation liquid. At the same time, with the penetration of the impregnation liquid, the moisture content of the thicker layer of the veneer is increased and softened, which in turn promotes the compression process. Examples 2, 6, 10, and 14 are limited by the thickness of the veneer and actually form an overall compression.

[0074] In contrast, in the step-by-step method adopted in the prior art, taking the immersion depth of 1 mm as an example, only the moisture content of the layer with a thickness of 1 mm is significantly increased to the extent that it can be compressed, and due to the existence of the semi-drying process, the compression process will not further promote the impregnation liquid already present in the 1 mm thickness to migrate further inward, so only this thickness layer can be compressed.

[0075] The above description is intended to be illustrative and not limiting. Upon reading the above description, many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art. Therefore, the scope of the present teachings should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of the subject matter, nor should it be considered that the applicant has not considered the subject matter to be part of the disclosed application subject matter.

Claims

1. A method for enhancing and modifying the cell wall of a fast-growing timber veneer, wherein the treated surface of the veneer is placed above the liquid surface of an impregnation liquid, characterized in that: The moisture content of the veneer is 3-20%, and the other side of the veneer is a pressure-bearing surface. When the pressing plate contacts the pressure-bearing surface, the liquid surface of the impregnating liquid, the wall surface of the container for filling the impregnating liquid, and the air pressure in the space formed by the pressing plate are in a stable state, and then the pressing plate is pressurized so that the pressure-bearing surface is subjected to a uniform pressure on its width; The thickness of the veneer is not less than 2 mm, and the treated surface is the cut back side of the wood; The solution temperature of the impregnation liquid is 60-120° C., and the pressure on the pressure-bearing surface is 4-12 MPa; When the modification method includes a single impregnation liquid pressure impregnation process, the impregnation liquid is a nano silicon solution; when the modification method includes a first impregnation liquid pressure impregnation process and a second impregnation liquid pressure impregnation process, the impregnation liquid used in the first impregnation liquid pressure impregnation process is a calcium chloride solution, and the impregnation liquid used in the second impregnation liquid pressure impregnation process is an ammonium bicarbonate solution; After the pressing plate enters the container, the liquid level of the impregnating liquid, the wall surface of the container for filling the impregnating liquid, and the air pressure in the space formed by the pressing plate are maintained by allowing the impregnating liquid to leave the container; when the pressing plate contacts the pressure surface, the container is in a sealed state; The time taken to complete the process from placing the single board to the pressing plate contacting the pressure surface of the single board is no more than 3 minutes.

2. The method for enhancing and modifying the cell wall of a fast-growing timber veneer according to claim 1, characterized in that: The modification method comprises a first impregnation liquid pressure impregnation process and a second impregnation liquid pressure impregnation process; The first impregnation liquid pressure impregnation process is to place the single board in a manner that the treated surface floats on the liquid surface of the first impregnation liquid, the temperature of the first impregnation liquid is 60-100° C., and then apply pressure to the pressure surface; The second impregnation liquid pressure impregnation process is to replace the first impregnation liquid with a second impregnation liquid having a temperature of 80-120° C., and then apply pressure to the pressure-bearing surface.

3. The method for enhancing and modifying the cell wall of a fast-growing timber veneer according to claim 2, characterized in that: The pressurization time of the pressure impregnation process of the first impregnation liquid is 30 to 40 minutes, and the pressurization time of the pressure impregnation process of the second impregnation liquid is 25 to 35 minutes.

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