Wood compression and shaping integrated treatment method and apparatus

Abstract

Disclosed in the present invention are a wood compression and shaping integrated treatment method and apparatus. The treatment method comprises the following steps: heating a hot press to a target temperature for hot pressing, the temperature range being 80-250°C; putting wood with adjusted moisture content into the hot press, which is provided with a sealed frame or a sealed cavity between layers; closing an upper platen or a lower platen of the hot press to compress the wood, and compressing the wood to a target thickness while keeping the wood in a sealed space; adjusting the air pressure in the sealed space, such that the air pressure is maintained between 0.1 MPa and 1.5 MPa for 1-300 minutes, so as to perform a shaping treatment on the wood; and opening the hot press, and transporting the compressed and shaped wood from the hot press to a cold press, so as to perform a cold pressing and cooling treatment on the wood. In the present invention, cold pressing and shaping are directly performed after the hot pressing and compression of wood, such that the processing time can be effectively shortened, thereby improving the processing efficiency, and saving on energy.

Description

A wood compression and shaping integrated processing method and device Technical Field

[0001] The present invention relates to the field of wood processing, and in particular to a wood compression and shaping integrated processing method and device. Background Art

[0002] Wood compression technology involves softening wood, compressing it under mechanical force, and permanently fixing the compression deformation. This increases the density of the compressed wood, significantly improving mechanical properties such as hardness, strength, and modulus. There are two key challenges in compressed wood production: the softening and compression techniques for the wood and the permanent fixation of the compression deformation.

[0003] There are many reported methods for softening, compressing, and fixing compression deformation in wood, which can be broadly categorized into two main groups: chemical and physical. Chemical methods involve impregnating the wood with a low-molecular-weight, water-soluble resin, compressing it in a hot press, maintaining the pressure under mechanical force for a specified period, and then cooling and drying to set the shape. This yields highly stable compressed wood. Commonly used low-molecular-weight resins include phenolic resins, melamine resins, urea-formaldehyde resins, and glyoxal resins. This method allows for both compression and setting, but the use of chemical agents pollutes the environment and poses health risks, as well as being costly. Physical methods involve softening the wood by steaming or moist heat, followed by mechanical compression to produce compressed wood. Cooling and drying produce compressed wood that is stable in dry environments. Post-heat treatment, such as heat treatment, pressurized superheated steam treatment, or saturated steam treatment, is then used to set the shape, permanently fixing the compression deformation and resulting in a compressed wood product with high stability in moist heat environments. Existing physical methods require the wood to be hot-pressed, then cooled in the press. After cooling, the wood is removed from the press and then sent to a shaping device for heating and shaping. Compared to chemical methods, physical methods do not require any chemical additives during the treatment process, are environmentally friendly, and have greater advantages and prospects for commercial application.

[0004] Currently, the physical production of compressed wood requires two processes: compression and shaping. This requires both compression and shaping equipment. Furthermore, unshaped compressed wood easily returns to its original shape under hot and humid conditions. In existing physical methods, after the wood is cooled in the hot press and then removed from the press and transported to the shaping equipment for shaping, the high-pressure steam environment can easily cause the compressed wood to significantly return to its original shape during the shaping process. Therefore, when using a post-compression heat treatment method for shaping, the compressed wood must be clamped under a very high clamping force before the shaping process is performed. This shaping process requires equipment that can withstand both mechanical and steam pressures, making both the equipment and the production process relatively complex. Summary of the Invention

[0005] The present invention aims to provide a method and apparatus for integrated wood compression and shaping. This method utilizes cold-pressing and shaping directly after hot-pressing the wood, effectively shortening processing time, improving processing efficiency, and conserving energy. Furthermore, the compressed wood produced by this method exhibits high stability and controllable moisture content.

[0006] The technical solution of the present invention is a method for integrating wood compression and shaping, comprising the following steps:

[0007] S1: Heat the hot press to the target temperature of hot pressing, the temperature range is 80-250℃;

[0008] S2: The wood with adjusted moisture content is placed in a hot press with a sealed frame or sealed cavity between layers for sealing treatment;

[0009] S3: Close the upper or lower pressing plate of the hot press to compress the wood, and keep the wood in a closed space while compressing the wood to the target thickness;

[0010] S4: Adjust the air pressure in the enclosed space so that the air pressure is maintained between 0.1-1.5 MPa for 1-300 minutes to shape the wood;

[0011] S5: Open the hot press and transfer the compressed and shaped wood from the hot press to the cold press to cool the wood; or directly cool the hot press to cool the compressed wood in the press;

[0012] S6: The cooled wood is removed from the cold press or the cooled hot press to complete the compression and shaping of the wood.

[0013] In the aforementioned integrated wood compression and shaping processing method, the wood needs to be wetted, soaked in water or steamed before being placed and sent into the hot press.

[0014] In the aforementioned integrated processing method for wood compression and shaping, the hot press with a sealed frame or sealed cavity between layers includes: pre-arranging a mold frame or mold cavity on the upper platen or lower platen of each layer of the hot press, or loading a mold frame or mold cavity on the upper platen or lower platen of each layer of the hot press; if the mold frame or mold cavity is set on the lower platen, the wood is placed in the mold frame or mold cavity; if the mold frame or mold cavity is set on the upper platen, the wood is placed directly below the mold frame or mold cavity.

[0015] In the aforementioned integrated wood compression and shaping processing method, the mold frame is a metal frame with a side length less than or equal to the width of the hot press, the mold cavity includes the frame and a metal plate with a side length the same as the outer size of the frame, and the frame and the metal plate are welded into a cavity.

[0016] In the aforementioned integrated wood compression and shaping processing method, the mold frame or the side wall of the mold cavity is provided with one or more air flow channels. In step S4, gas is introduced into or discharged into the mold frame through the air flow channel to adjust the air pressure in the mold frame. The gas is steam, nitrogen or air.

[0017] In the aforementioned integrated wood compression and shaping processing method, the side wall of the mold frame is also provided with a temperature measuring channel and a pressure measuring channel, wherein the end of the temperature measuring channel is connected to a temperature measuring device for monitoring the temperature in the mold frame or the mold cavity; the end of the pressure measuring channel is connected to a pressure measuring device for monitoring the gas pressure in the mold frame.

[0018] In the aforementioned integrated wood compression and shaping processing method, grooves are provided on the upper and lower surfaces of the mold frame and the surface of the mold cavity, and sealing strips are embedded in the grooves. The sealing strips are used to improve the sealing of the mold frame and the inside of the mold cavity; the four inner corners of the frame are all arc-shaped.

[0019] In the aforementioned integrated wood compression and shaping processing method, the height of the sealing strip is higher than the surface of the mold frame. After the upper or lower pressing plate of the hot press compresses the wood, the opposite pressing plate compresses the wood. When the wood is compressed to the target thickness, the pressing plate and the sealing strip of the mold frame are completely fitted together, so that the mold frame reaches a closed state and forms an enclosed space.

[0020] In the aforementioned integrated wood compression and shaping processing method, the hot press and the cold press are both equipped with a feeding device and a discharging device, and the hot-pressed wood is directly fed into the cold press or fed into the cold press through the feeding device.

[0021] The device for realizing the above-mentioned integrated wood compression and shaping treatment method comprises a hot press, wherein a closed frame or a closed cavity is installed between the layers of the hot press.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. In the present invention, after the wood is placed in the hot press, the wood is compressed by the pressing plate of the hot press. While the wood is compressed to the target thickness, the wood is placed in a closed space, and then gas is introduced into the mold frame to regulate the pressure and proportion of the gas to help the compressed wood to be shaped. In summary, in the present invention, when processing the wood, the wood that has reached the target thickness is shaped while the wood is kept compressed. Compared with the existing compression and shaping process, in the processing method provided by the present invention, after the wood is compressed and shaped in the hot press, it does not need to be cooled down. It can be directly transported out of the hot press at high temperature and then sent to the cold press for cold pressing and cooling treatment by the cold press to finally obtain the finished wood product after compression and shaping; or the hot press can be directly cooled down to cool down the compressed wood in the mold frame after compression and shaping treatment to obtain the finished wood product after compression and shaping. In summary, in the present invention, the wood does not need to be cooled in a hot press and then heated again in a shaping device. The compression and shaping work can be effectively connected and carried out. The obtained compressed wood is not easy to recover, the compressed wood is more stable, and the processing time of the wood is greatly shortened, thereby improving the processing efficiency of the wood.

[0024] 2. In the present invention, when the wood is sealed, a mold frame is pre-set on the upper or lower platen of the hot press, and the wood is placed in the mold frame for compression. The height of the mold frame is set according to the target thickness of the compressed wood. When the upper platen of the hot press fits the mold frame, it means that the wood has been compressed to the target thickness, which can improve the accuracy of the compressed thickness of the wood.

[0025] 3. In the present invention, during the shaping process, gas is introduced into or exhausted from the mold frame to adjust the ratio and pressure of the gas, wherein the gas includes steam, nitrogen or air. By mixing steam with air or nitrogen, the required amount of steam is reduced, saving costs. Moreover, by controlling the ratio of the three types of media, the moisture content of the compressed and shaped wood can be regulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic structural diagram of a mold frame in the present invention;

[0027] FIG2 is a schematic diagram of a hot press with closed frames or closed cavities between layers;

[0028] FIG3 is a schematic diagram of a hot press with a closed frame or closed cavity between layers after wood is placed;

[0029] FIG4 is a schematic diagram of the hot press when it is closed to compress the wood to the target thickness.

[0030] The markings in the accompanying drawings are: 1-sealed frame or sealed cavity; 101-metal plate; 102-frame; 103-air flow channel; 104-temperature measurement channel; 105-pressure measurement channel; 106-sealing strip; 2-upper pressure plate; 3-lower pressure plate; 4-pressing cylinder; 5-wood. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and examples, but they are not intended to limit the present invention.

[0032] Embodiment: A method for integrating wood compression and shaping comprises the following steps:

[0033] S1: Heat the hot press to the target temperature of hot pressing, the temperature range is 80-250℃.

[0034] S2: The moisture-adjusted wood 5 is placed in a hot press with a sealed frame or sealed cavity 1 between layers for sealing. In this embodiment, the hot press has a platen thickness greater than 4 cm and a built-in heating and cooling system. The pressure is greater than 2 MPa. Specifically, the hot press can be heated by water, oil, or electricity. Before placing the wood in the hot press, it needs to be wetted, soaked, or steamed. As shown in Figure 2, the hot press with a sealed frame or sealed cavity 1 between layers includes: a mold frame or mold cavity pre-installed on the upper platen 2 or lower platen 3 of each layer of the hot press, or a mold frame or mold cavity is loaded on each layer of the upper platen 2 or lower platen 3 of the hot press. As shown in Figure 3, if the mold frame or mold cavity is located on the lower platen 3, the wood 5 is placed inside the mold frame or mold cavity; if the mold frame or mold cavity is located on the upper platen 2, the wood 5 is placed directly below the mold frame or mold cavity. As shown in Figure 1 , the mold frame is a metal frame with a side length equal to or less than the width of the hot press. The mold cavity comprises the frame 102 and a metal plate 101 with a side length equal to the outer dimensions of the frame 102. The frame 102 and the metal plate 101 are welded together to form the cavity. The four inner corners of the frame 102 are curved, and the height of the frame 102 is determined by the target thickness of the wood 5 to be compressed.

[0035] S3: As shown in FIG4 , the press cylinder 4 is started, and the upper pressing plate 2 or the lower pressing plate 3 of the hot press is closed to compress the wood 5 until the wood 5 is compressed to the target thickness. At this time, the wood 5 is in a confined space.

[0036] S4: Adjust the air pressure in the enclosed space so that the air pressure is maintained between 0.1-1.5 MPa for 1-300 minutes to shape the wood 5; In this embodiment, the side wall of the mold frame or mold cavity is provided with an air flow channel 103, through which gas is introduced or discharged into the mold frame, thereby adjusting the air pressure and gas ratio in the mold frame, wherein the gas includes steam, nitrogen or air. By mixing steam with air or nitrogen, the required amount of steam is reduced, and by controlling the ratio of the three types of media, the moisture content of the compressed and shaped wood 5 can be controlled; The upper and lower surfaces of the mold frame and the surface of the mold cavity are provided with grooves, and the grooves are embedded with sealing strips 106, which are used to improve the sealing of the interior of the mold frame. The side wall of the mold frame is also provided with a temperature measurement channel 104 and a pressure measurement channel 105, wherein the end of the temperature measurement channel 104 is connected to a temperature measurement device for monitoring the temperature in the mold frame; the end of the pressure measurement channel 105 is connected to a pressure measurement device for monitoring the gas pressure in the mold frame.

[0037] S5: Open the hot press and transfer the compressed and shaped wood 5 from the hot press to the cold press for cooling. Alternatively, the hot press is directly cooled to cool the compressed wood 5 inside. Both the hot press and the cold press are equipped with a feeder and a discharger. Furthermore, the discharger of the hot press can serve as the feeder of the cold press, reducing the overall size of the press. The hot-pressed wood 5 is fed directly into the cold press or via a feeder.

[0038] S6: The cooled wood 5 is removed from the cold press or the hot press to complete the compression and shaping of the wood 5.

[0039] In the above processing method, the wood does not need to be cooled after being compressed in the hot press. It is directly transported out of the hot press at high temperature and then sent to the cold press for cold pressing treatment, and finally a compressed and shaped wood product is obtained.

[0040] In summary, in the present invention, the wood does not need to be cooled in a hot press and then heated again in a shaping device. The compression and shaping work can be effectively connected and carried out. The compressed wood is not easy to recover, the compressed wood is more stable, and the processing time of the wood is greatly shortened, thereby improving the processing efficiency of the wood.

[0041] The present invention also provides a device for realizing the above-mentioned integrated wood compression and shaping processing method, comprising a hot press, wherein a closed frame or a closed cavity is installed between the layers of the hot press.

Claims

1. A method for integrated wood compression and shaping, characterized in that: The following steps are involved: S1: Heat the hot press to the target temperature of hot pressing, the temperature range is 80-250℃; S2: placing the wood with adjusted moisture content into a hot press with a closed frame or closed chamber between layers; S3: closing the upper pressing plate or the lower pressing plate of the hot press to compress the wood, and keeping the wood in a closed space while compressing the wood to a target thickness; S4: Adjust the air pressure in the enclosed space so that the air pressure is maintained between 0.1-1.5MPa for 1-300 minutes to shape the wood; S5: Open the hot press, transport the compressed and shaped wood from the hot press to the cold press, and perform cold pressing and cooling treatment on the wood; or directly cool the hot press to cool the compressed wood in the press; S6: The cooled wood is removed from the cold press or the cooled hot press to complete the compression and shaping of the wood.

2. The method for integrated wood compression and shaping according to claim 1, characterized in that: Before the wood is laid out and fed into the hot press, it needs to be wetted, soaked or steamed.

3. The method for integrated wood compression and shaping according to claim 1, characterized in that: The hot press with a sealed frame or a sealed cavity between layers includes: pre-arranging a mold frame or a mold cavity on the upper pressing plate or the lower pressing plate of each layer of the hot press, or loading a mold frame or a mold cavity on the upper pressing plate or the lower pressing plate of each layer of the hot press; if the mold frame or the mold cavity is arranged on the lower pressing plate, the wood is placed in the mold frame or the mold cavity; if the mold frame or the mold cavity is arranged on the upper pressing plate, the wood is placed directly below the mold frame or the mold cavity.

4. The method for integrated wood compression and shaping according to claim 3, characterized in that: The mold frame is a metal frame with a side length less than or equal to the size of the hot press format. The mold cavity includes the frame and a metal plate with a side length the same as the outer size of the frame, and the frame and the metal plate are welded into a cavity.

5. The integrated wood compression and shaping method according to claim 3, characterized in that: The mold frame or the side wall of the mold cavity is provided with one or more air flow channels. In step S4, gas is introduced into or discharged into the mold frame through the air flow channel to adjust the air pressure in the mold frame. The gas is steam, nitrogen or air.

6. The integrated wood compression and shaping method according to claim 3, characterized in that: The side wall of the mold frame is also provided with a temperature measuring channel and a pressure measuring channel, wherein the end of the temperature measuring channel is connected to a temperature measuring device for monitoring the temperature in the mold frame or the mold cavity; the end of the pressure measuring channel is connected to a pressure measuring device for monitoring the gas pressure in the mold frame.

7. The integrated wood compression and shaping method according to claim 4, characterized in that: The upper and lower surfaces of the mold frame and the surface of the mold cavity are both provided with grooves, and sealing strips are embedded in the grooves. The sealing strips are used to improve the sealing performance of the mold frame and the inside of the mold cavity; the four inner corners of the frame are all arc-shaped.

8. The method for integrated wood compression and shaping according to claim 7, characterized in that: The height of the sealing strip is higher than the surface of the mold frame. When the upper pressing plate or the lower pressing plate of the hot press compresses the wood, the relative pressing plate compresses the wood. When the wood is compressed to the target thickness, the pressing plate and the sealing strip of the mold frame are completely fitted, so that the mold frame reaches a closed state and forms a closed space.

9. The integrated wood compression and shaping method according to claim 1, characterized in that: The hot press and the cold press are equipped with a feeding device and a discharging device, and the wood after hot pressing is directly fed into the cold press or fed into the cold press through the feeding device.

10. A device for implementing the integrated wood compression and shaping treatment method according to any one of claims 1 to 9, characterized in that: The invention comprises a heat press machine, wherein a closed frame or a closed cavity is arranged between the layers of the heat press machine.

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