High frequency based fixed length compaction plate

Abstract

To provide a standard length consolidation plate which has good processing performance such as screw gripping force, flexural strength, flexural elasticity, and so on and acceleration aging prevention performance, and a method for manufacture of which is easy to mass produce and low cost.SOLUTION: A standard length consolidation plate based on high frequency includes some longitudinally joined consolidation wood boards which are connected in a width direction, each longitudinally joined consolidation wood board includes some consolidation wood board filaments which are connected in a longitudinal direction, and each consolidation wood board filament includes a cork board filament of one layer or cork board filaments connected in multiple layers processed by a high frequency hot press step in a thickness direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to the field of wood processing technology, specifically to high frequency based compaction of standard length boards. [Background technology]

[0002] The medium-density fiberboard, particle board, multi-layer board, and log board used in board-type furniture are basically standard-sized boards, for example, 48 shaku (length and width dimensions are 1220mm x 2440mm) and 49 shaku (length and width dimensions are 1220mm x 2745mm). However, the related art does not disclose standard-sized compressed wood used in the customized furniture industry. CN111347511 A (2020.06.30) discloses a method for manufacturing adhesive-free composite materials based on high-frequency mixed materials, with a density of at least two densities of 0.7kg / m². 3The method involves heating and pressurizing two adjacent wood boards, each not exceeding 100 mm thick, using high frequency waves to form a bonded layer between them. The manufacturing process specifically includes pre-treatment, lamination, heating and pressurizing, hardening, cooling, and curing. However, the material produced in this patent is not a horizontally joined compressed board, but a multi-layer compressed board, and producing standard length boards is difficult to mass-produce and expensive. CN112847694 A (May 28, 2021) discloses an adhesiveless horizontal joint consolidation device (see Figure 1, where 1 is a lower pressure plate, 2 is an upper pressure plate, 4 is a lower backing plate, 5 is an upper backing plate, 6 is a hydraulic rod, and 30 is a horizontal joint plate) and an adhesiveless horizontal joint consolidation method, which includes the steps of: (1) arranging several horizontal joint plates in a plane in order, sandwiching a resin film between two adjacent horizontal joint plates, and making the contact surfaces of the two adjacent horizontal joint plates form an angle of 45-135° with the plane; The method includes the steps of: (2) applying a first biasing force F1 in the horizontal direction of the array plate, where F1 is 1.5-2 MPa; (3) heating the array plate to 60-170°C and applying a second biasing force F2 in the vertical direction of the array plate, where F2 is 0.7 MPa or more, and maintaining the pressure for 8-10 minutes; and (4) while maintaining F2, increasing F1 to F3, where F3 is 2.5-4 MPa, and maintaining the pressure until the temperature of the array plate reaches 40-70°C. This patent uses heating during the molding process to produce horizontally bonded consolidated boards, but producing standard-sized boards is still difficult to mass-produce and expensive. Summary of the Invention

[0003] In view of at least the above technical problems, several embodiments of the present invention provide a constant-length compacted board based on high frequency, which includes several longitudinally joined compacted wood boards connected in the width direction, each longitudinally joined compacted wood board including several longitudinally joined compacted wood board strips, and each compacted wood board strip includes one layer of cork board strips or multiple layers of joined cork board strips processed by a high-frequency hot pressing step in the thickness direction.

[0004] Furthermore, in the fixed-length compacted board, the longitudinal joint contact surface of the adjacent compacted wood board strips in the longitudinal direction of each fixed-length compacted board (or each vertically joined compacted wood board) is a curved surface or an inclined surface, and the inclined surface includes an inclined plane or an inclined curved surface, preferably, the curved surface or the inclined curved surface is a sawtooth surface; The horizontal joint contact surface of the adjacent compressed wood board strips in the width direction of each standard length compressed board (or each horizontally joined compressed wood board) is a flat or inclined surface, and the inclined surface includes an inclined flat surface or an inclined curved surface, and preferably, the inclined curved surface is a sawtooth surface; Adjacent longitudinal contact surfaces or adjacent lateral contact surfaces are connected by a resin layer, and the resin layer may be one or more of a PVA resin layer, a PVB resin layer, or a PVC resin layer, but is not limited to this. The resin used for the resin layer may be any one or a mixture of more than one of an ethylene-vinyl acetate copolymer or a polyolefin material, and the polyolefin material may be any one or a mixture of at least two of polyethylene, polypropylene, modified polyethylene, modified polypropylene, or an ethylene elastomer containing an ethylene unit.

[0005] Furthermore, in the case of a fixed-length compacted plate, the manufacturing process of the fixed-length compacted plate is as follows: a first preheating step in which several cork slabs with a moisture content of 10% to 20% are irradiated with infrared light to raise the average temperature to 80 to 90°C, thereby obtaining several preheated cork slabs; a water layer deposition step of depositing a water layer on the surface of the preheated cork slab irradiated with infrared light to obtain several water layer-deposited cork slabs; a high-frequency hot pressing step in which the water-layer-attached cork boards are subjected to a heat compression treatment and hardening treatment under high-frequency conditions to obtain several compacted wood boards; A cooling step in which some of the compressed wood boards are cooled to an average wood temperature of 70 to 90 ° C or room temperature; a longitudinal joining step of joining longitudinally adjacent cooled compacted wood board strips to obtain several longitudinally joined compacted wood boards; a horizontal joining step of joining adjacent longitudinally joined compacted wood boards in the width direction to obtain several horizontally joined compacted wood boards; and a sizing step of cutting several transversely bonded compacted wood boards to size into several compacted boards.

[0006] Furthermore, in the fixed-length compacted board, the water layer-attached cork board is subjected to the high-frequency hot pressing step through a second preheating step, during which: In the second preheating step, several cork strips with the water layer attached are irradiated with infrared light to maintain an average temperature of 80 to 90°C.

[0007] Furthermore, in the fixed-length compaction plate, in the first preheating step and / or the second preheating step, infrared irradiation is carried out in an infrared irradiation space, and the temperature of the infrared irradiation space is 130 to 150°C.

[0008] Furthermore, in the water layer attachment step, water is applied or sprayed onto the surface of the preheated cork strips on a fixed-length compaction plate one to four times.

[0009] Furthermore, in the fixed-length compaction plate, the step of forming the resin layer is as follows. In step S1, the joint end surface of the compacted wood board is processed into a curved or inclined surface, and the inclined surface includes an inclined plane or an inclined curved surface, and preferably, the curved surface or the inclined curved surface is a sawtooth surface; In S2, the resin is hot-melted to produce a hot-melt resin, and the hot-melt resin is applied to the joining end surface of the compacted wooden board; In S3, the joining end faces of the adjacent compacted wooden boards are pressed with a first biasing force.

[0010] Furthermore, in the case of the fixed-length compaction board, in step S2, after the resin is hot-melted, 20-40 mesh resin particles are added and mixed uniformly to obtain a paste-like hot-melt resin, which is then applied to the end surface of the fixed-length compaction board, with the weight ratio of the resin to the resin particles being 8:1-12:1, and the resin particles include, but are not limited to, one or more of PVA particles, PVB particles, and PVC particles.

[0011] Furthermore, in the cooling process step for the fixed-length compacted boards, several compacted wood boards are cooled to room temperature for 9 to 15 minutes in an environment of -150℃ to -130℃ using liquid nitrogen freezing technology, and then joined vertically. [Effects of the Invention]

[0012] The beneficial effects of the present invention are as follows: The high-frequency compacted plate of the present invention has good processing performance such as good screw gripping force, bending strength, bending elasticity, etc., and excellent anti-accelerated aging performance, and its manufacturing method is easy to mass-produce and low cost. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a prior art horizontal joint consolidation device. [Figure 2] This is a fixed-length compaction plate according to an embodiment of the present invention. [Figure 3] This is a vertically joined, compacted wood board according to an embodiment of the present invention. [Figure 4] FIG. 1 is a schematic diagram of a transverse joint. [Figure 5] This is a fixed-length compaction plate according to an embodiment of the present invention. [Figure 6] FIG. 1 is a side view of a fixed-length compaction plate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following examples further illustrate the present invention but should not be construed as limiting thereof. Any modifications or substitutions made to the methods, steps, or conditions of the present invention that do not depart from the spirit and substance of the present invention are within the scope of the present invention.

[0015] Interpretation of terms Standard lengths refer to the manufacture of plates with lengths and widths specified by product standards, and as will be appreciated, standard length plates are more suitable for robotic and pipeline operations, and can be mass-produced to reduce costs.

[0016] Single pressing means that the hot press machine hot presses one layer of wood board.

[0017] Combination pressing refers to the hot pressing of multiple layers of wood boards by a hot press machine. For example, when a hot press machine hot presses three layers of wood boards, it is called "three-combination pressing."

[0018] Vertical splicing, also known as longitudinal splicing or straight-pressing, is the joining of adjacent wooden boards in the longitudinal direction.

[0019] Horizontal splicing, also known as horizontal splicing or fixed-length lateral splicing, refers to joining adjacent wooden boards in the width direction, as shown in Figure 4.

[0020] Regarding the joint end surface, as shown in Figure 4, the end surface of the wooden board includes six surfaces, and the joint end surface 9 is one end surface for joining the wooden board. After joining, the joint end surface can also be called the vertical joint contact surface or the horizontal joint contact surface.

[0021] Referring to the resin layer as shown in FIG. 4, the resin layer 8 is located between the joining end faces 9 .

[0022] The first biasing force is a first biasing force F1 applied in a horizontal direction, which can be realized by, for example, an air compaction device, see Chinese Patent Application CN112847694 A.

[0023] The second biasing force is a second biasing force F2 applied in the vertical direction, which can be realized, for example, by a high-frequency hot press, as described in Chinese Patent Application CN112847694 A. The uses of the compacted board of the present invention are not specifically limited, and in addition to being used as a base material for board-type furniture, it can also be used as a flooring base material, i.e., a base material for decoratively finished artificial boards.

[0024] Optional equipment for use in embodiments of the present invention includes, but is not limited to, slicers, infrared preheating equipment, water layer deposition equipment (which may be a coating equipment or a spray equipment), high-frequency hot presses, liquid nitrogen freezing equipment, square groove processing machines, sorting systems, tooth driving equipment, roll coaters, air compaction equipment (including hydraulic press-based clamping devices for various board pipelines), woodworking breakers, and wood board printing machines. Chinese Patent Application No. CN201811592197 - High-frequency adhesive-free compaction equipment, Chinese Patent Application No. CN201910181348 - High-frequency compacted wood assembly production line, Chinese Patent Application No. CN201922120903 - Adhesive-free horizontal joint compaction equipment, and Chinese Patent Application No. CN202010100409 - Equipment for uniformly discharging compressed water vapor from the surface of compacted wood and compacted wood equipment pipeline equipment. Equipment or production lines reconstructed based on the concept of the present invention are also within the scope of protection of the present invention.

[0025] In an embodiment of the present invention, the optional infrared preheating equipment is a number of infrared preheating boxes that can be installed on a conveying device (which may be a conveying chain or rollers) of a production line. That is, the conveying device can carry the plate material and pass through the interior of the several infrared preheating boxes from below. Each infrared preheating box includes an infrared heating preheating tube installed at the top of the interior of the box. The wattage of the infrared heating preheating tube is adjustable, so that the space temperature in the infrared preheating box is always maintained at about 150°C. The length of the infrared preheating box in the production line can be set according to the process requirements. When the length of the infrared preheating box in the production line is predetermined, the speed of the conveying device (e.g., conveying chain) can be further adjusted to achieve the preheating temperature of the plate material between 60°C and 100°C. For example, if the preheating temperature is 100°C, the speed rate is slow, and if the preheating temperature is 60°C, the speed is fast.

[0026] The optional water layer application device in an embodiment of the present invention is several water layer applicators that can be installed on a conveying device (which may be a conveying chain or roller) of the production line. That is, the conveying device can carry the board material and pass through the box of several applicators from below. Each water layer applicator includes a group of applicator rollers (including one driving roller and one driven roller) installed inside the box, and a water supply device. The water supply device can spray water onto the group of applicator rollers, which can then apply water to the wooden board and further adhere the water layer to the wooden board. The number of water layer applicators or the number of roller groups can be configured according to the process requirements. For example, each water layer applicator can be installed with one group of applicator rollers, or with two groups of applicator rollers. Obviously, if two applications are required, two of the former and one of the latter are required. The application speed (the rotation speed of the roller group) is usually always consistent with the running speed of the conveying device.

[0027] The liquid nitrogen freezing equipment of the present invention can be selected from several liquid nitrogen freezing boxes that can be installed on a conveying device (which may be a conveying chain or roller) of a production line, that is, the conveying device can carry the plate material and pass through the interior of several liquid nitrogen freezing boxes from below. The temperature inside the liquid nitrogen freezing box is about -150℃ to -130℃.

[0028] The corresponding designs of the mechanical and electrical structures of the above-mentioned infrared preheating box, liquid nitrogen freezing equipment and water layer coating machine can be realized by known techniques, and will not be described in detail in this application.

[0029] The present invention will be described below with reference to the embodiments, and the methods of the Chinese patent applications cited therein are all full-text citations. Those skilled in the art can make direct citations or indirect citations with slight modifications based on the concept of the present invention, and the present invention does not specifically limit the citation method.

[0030] (Embodiment 1) Production of cork strips The cork strips used in the embodiments of the present invention can be manufactured using any known technology, such as a sawing process using a slicing method to control the moisture content to 60-80% (using a slicing method instead of a sawing process; poplar, which has a high moisture content, is more suitable for slicing, does not require pre-drying, and reduces substrate loss), or a steaming and slicing method (including the steps of selecting the material, steaming, slicing, and air-drying). The dimensions of the cork strips used in the embodiments of the present invention are determined based on the dimensions of the standard compacted board. For example, a 48-foot (4 feet x 8 feet) standard compacted board is manufactured. The cork strips can be 1-4 cm thick and 22 cm or 44 cm wide, and the cork is typically poplar. The moisture content of the cork strips is generally 10-20%.

[0031] (Embodiment 2) Production of water-layer-attached cork strips In some embodiments of the present invention, the water layer is applied 2-4 times using the water layer coater to attach a water layer to the surface of the preheated cork strip irradiated with infrared light, resulting in several water-layer-attached cork strips. The water layer coater is easily installed via a pipeline, but in an optional embodiment, a spray device can be used to attach the water layer to the surface of the preheated cork strip. Of course, for small-scale production, a thin water layer can be manually applied to the surface of the preheated cork strip. The water-layer-attached cork strip generates hot steam during high-frequency hot pressing, which further changes the wood texture of the resulting compacted wood board (reducing hairlines). Other implementations based on the concept of the present invention are also within the scope of protection of the present invention.

[0032] (Embodiment 3) Manufacturing of compressed wooden boards (single compression) The method for producing the compacted wooden boards (single compression) used in the embodiments of the present invention includes at least the steps of heat compression treatment and hardening treatment, and an optional embodiment includes cooling treatment and curing treatment. The method hereinafter is based on Chinese patent application CN109465932A, and the optional method for producing the compacted wooden boards (single compression) used in the embodiments of the present invention is as follows:

[0033] In the heat compression treatment, the wood is heated by high frequency until the average temperature of the wood reaches 100-110°C, kept at that temperature for 5-7 minutes, and then compressed at the first compression ratio.

[0034] In the hardening process, the wood that has been heat-compressed is heated by high frequency until the average temperature of the wood reaches 180-220°C, and then the temperature is maintained for 5-8 minutes to harden the wood.

[0035] During the cooling process, the hardened wood surface is cooled using water cooling technology at a rate of 5-15°C / min until the average temperature of the wood reaches 70-90°C. The water flow rate in the water cooling technology is 0.9-1.3 m / s. During the cooling process, once the wood surface temperature reaches 85-90°C, air cooling is carried out at a wind speed of 9.2-9.7 m / s and a wind temperature of 55-60°C.

[0036] During the curing process, the cooled wood is placed at room temperature and cured for 13-15 days to obtain adhesive-free compacted hardwood. The specific curing method is to place the cooled wood on a horizontal drying surface, apply a pressure of 5.5-7.2 MPa to the upper surface of the wood, cure for 3 days, then reduce the pressure by 1.2-1.5 MPa every day until the pressure reaches 0, and continue curing for 10-12 days.

[0037] (Embodiment 4) Manufacturing of compressed wooden boards (three-component pressure) The method for producing densified wooden boards (three-way pressure) used in the embodiments of the present invention includes at least the steps of hot compression treatment (also called hot pressure treatment) and hardening treatment, and optional embodiments include cooling treatment (also called temperature reduction treatment) and curing treatment. The following method is based on Chinese patent application CN111347511A, and optional methods for producing densified wooden boards (three-way pressure) in the embodiments of the present invention are as follows:

[0038] In the lamination process, two or more wood boards are stacked and placed according to at least one force-bearing direction to obtain a laminated wood board, where the force-bearing direction includes a direct pressure direction and an indirect pressure direction.

[0039] In the heat and pressure treatment, the deteriorated connecting layer of the laminated wood board is heated until the wood board temperature reaches 80-100°C, kept at that temperature for 4-6 minutes, and then subjected to pressure treatment at a predetermined compression rate based on the force receiving direction.

[0040] In the hardening process, the heated and pressurized wood board is heated by high frequency until the board temperature reaches 180-220℃, and then kept at that temperature for 5-8 minutes to harden the board, producing a hardened wood board.

[0041] In the temperature reduction process, the hardened wood board surface is cooled by water cooling at a rate of 5-15℃ / min until the wood board temperature reaches 70-90℃. The water flow rate in the water cooling process is 0.9-1.5m / s, and the wood board surface temperature reaches 85-90℃. Then, wind cooling is performed at a wind speed of 9.2-9.7m / s and a wind temperature of 55-60℃.

[0042] In the curing process, the cooled wood board is left at room temperature for 15-20 days to obtain an adhesive-free composite material based on the high-frequency admixture.

[0043] The standard length compressed boards manufactured based on the compressed wood board strip (three-layer compression) have a three-layer design in the thickness direction and two joints in the width direction. The adjacent laminated wood boards allow the horizontal and vertical stresses to interact and offset each other, which shows the anti-rebound performance of the structure. In addition, the wood properties of different slices are inevitably different, so the hot After being pressed, the unique grooves of the standard compacted board (corresponding to anti-counterfeit grooves) are formed on the sides, making it similar to natural wood, a characteristic not found in other products such as particle board.

[0044] (Embodiment 5) Manufacturing of vertically joined compressed wood boards The manufacturing method of vertically bonded compacted wood boards used in the embodiments of the present invention includes, but is not limited to, the method described in Chinese Patent Application CN201911193101, which requires sandwiching a resin film between wood boards and then hot pressing. In addition, some embodiments of the present invention use the following resin-mixed material sandwiching method.

[0045] The cooled compacted wood board strips adjacent in the longitudinal direction are joined to obtain several vertically joined compacted wood boards, which specifically includes the following steps:

[0046] a) Mixing materials, heating and hot-melting the resin to obtain a resin hot-melt material, and then adding 20-40 mesh resin particles and stirring to obtain a resin kneaded material (also called paste-like hot-melt resin), the resin including but not limited to one or more of PVA, PVB, and PVC, and the resin particles including but not limited to one or more of PVA particles, PVB particles, and PVC particles.

[0047] b) Finger joint (compacted pipeline) is made by sawing the two end faces of a three-joint pressure plate cut to a specified length to obtain a finger jointed three-joint plate.

[0048] c) Using a roller machine, resin is applied to the comb tooth parts of the comb tooth triplet boards, and in the pipeline, the comb tooth triplet boards with resin applied are brought into contact at the head and tail, and the comb tooth parts of the two front and rear comb tooth triplet boards are pressed while operating in the air compression device of the pipeline, and the comb tooth connected triplet boards are transferred to a fixed length direct pressure air compression device.

[0049] d) In the fixed length direct pressure method, the plywood with the connected comb teeth is placed in a fixed length direct pressure air compaction device and pressed together to obtain a fixed length direct pressure compacted board.

[0050] (Embodiment 6) Manufacturing of horizontally joined compressed wood boards The manufacturing method of vertically bonded compacted wood boards used in the embodiments of the present invention includes, but is not limited to, the method described in Chinese Patent Application CN201911193101, which requires sandwiching a resin film between wood boards and then hot pressing them. In addition, some embodiments of the present invention use the following resin hot melt material sandwiching method.

[0051] a) The resin is heated to hot melt to obtain a resin hot melt material.

[0052] b) A resin hot melt material is applied between adjacent vertically joined compacted wooden boards in the width direction, and then a pressure is applied using an air pressure compacting device. The joining is completed using a fixed-length side pressure air pressure compacting device, resulting in several horizontally joined compacted wooden boards (also called fixed-length side pressure compacted boards).

[0053] (Embodiment 7) Manufacturing of standard-length compacted plates As shown in Figures 2 and 3, the fixed-length compressed board 1 of the present invention comprises several vertically joined compressed wooden boards 2 of the same dimensions compressed in the width direction, each of which comprises several compressed wooden board strips 3 compressed in the length direction, and each of which comprises several cork strips 4 compressed in the thickness direction by a high-frequency hot pressing step.

[0054] A vertical joint pattern 5 is formed at the joints of adjacent compacted wood board strips 3, a horizontal joint pattern 6 is formed at the joints of adjacent vertically joined compacted wood boards, and a plurality of high-frequency hot-pressed patterns 7 are formed at the joints of adjacent cork strips.

[0055] The vertical joint patterns 5 of adjacent vertically joined compacted wooden boards 2 are not on the same straight line.

[0056] The directions of the high-frequency hot-pressed patterns 7 of adjacent cork strips 4 are the same but do not intersect. Specifically, since the high-frequency hot-pressed patterns 7 are formed by high-frequency pressure molding, the wood properties of different cork strips 4 are inevitably different, and therefore, as shown in Figure 2, unique creases (corresponding to anti-counterfeiting creases) are formed on the sides of the standard-length compacted board after hot pressing.

[0057] Among the several vertically joined compacted wooden boards 2 of each fixed-length compacted board 1, the one located in the middle is a vertically joined compacted wooden board 2 of the same size, The widths of the several compacted wood board strips 3 of each vertically joined compacted wood board 2 are equal.

[0058] The fixed-length compacted board of the present invention has a density of 0.58 to 0.6, a strength equivalent to that of pine wood, and can replace particle board, multilayer board, and density board, and can be used as a cabinet board.It has the following properties: a board surface screw gripping force of 1400N to 1600N, a bending strength of 50MPa to 65MPa, and a bending elasticity of 6500MPa to 7500MPa.

[0059] The manufacturing process for the fixed-length compacted board is as follows: a first preheating step in which several cork strips with a moisture content of 10%-20% are irradiated with infrared light to heat them to an average temperature of 80-90°C, thereby obtaining several preheated cork strips; a water layer adhering step of adhering a water layer to the surface of the preheated cork strip irradiated with infrared light to obtain several water layer-adhered cork strips; a high-frequency hot pressing step in which the water layer-attached cork strips are subjected to a heat compression treatment and hardening treatment according to the method of Example 2 or Example 3 under high-frequency conditions to obtain several compacted wood boards; A cooling step of cooling some of the compressed wood boards according to the method of Example 2 or Example 3 until the average temperature of the wood is 70-90°C; a longitudinal joining step of joining longitudinally adjacent cooled compacted wood board strips to obtain several longitudinally joined compacted wood boards; a horizontal joining step of joining adjacent vertically joined compacted wood boards in the width direction to obtain several horizontally joined compacted wood boards, as shown in FIG. 4; and a sizing step of cutting several horizontally joined compacted wood boards into several standard-length compacted boards using a woodworking breaker.

[0060] In some embodiments of the present invention, the screw gripping force of standard compacted boards can be improved by at least 30%. Taking poplar as an example, the density reaches 0.58-0.6 and the strength is equivalent to that of pine. It can replace particle board, multi-layer board and density board, and can be used as cabinet board.

[0061] (Embodiment 8) Manufacturing of decoratively finished artificial boards In some alternative embodiments, the compacted board is used as a substrate for a decorative artificial board; The method further includes a pattern printing step in which several standard-sized compacted boards are rubbed and a pattern (printing layer) is printed on the board using a wood-printing machine to obtain several decoratively finished artificial boards.

[0062] The present invention will be further described below with reference to specific examples and comparative examples.

[0063] (Example 1) Manufacturing of standard size compacted plates 1. In the cork strip production step, referring to the method of embodiment 1, standard poplar strips (also known as cork strips) with a length of 50 cm-120 cm and a width of 22 cm are produced, and the moisture content is 15±3%.

[0064] 2. In the first preheating step, several cork strips with a moisture content of 15±3% are irradiated with infrared rays in the infrared preheating box until the average temperature reaches 80-90°C, and the temperature of the infrared irradiation space is 130°C, thereby obtaining several preheated cork strips.

[0065] 3. In the water layer attachment step, referring to embodiment 3, two water layer applicators each equipped with a set of application rollers are used to apply the water layer twice in total, attaching the water layer to the surface of the preheated cork strips irradiated with infrared rays, thereby obtaining several cork strips with the water layer attached.

[0066] 4. In the high-frequency hot pressing step, the water layer-attached cork strips are subjected to heat compression and hardening treatment under high-frequency conditions according to the method of embodiment 3 to obtain several compacted wooden boards.

[0067] 5. In the cooling step, several compressed wood boards are cooled according to the method of embodiment 3 until the average temperature of the wood reaches 70-90°C.

[0068] 6. In the longitudinal joining step, referring to the method of Chinese patent application CN201911193101, adjacent cooled compacted wooden board strips are joined in the longitudinal direction to obtain several longitudinally joined compacted wooden boards.

[0069] 7. In the horizontal joining step, referring to the method of Chinese patent application CN201911193101, adjacent vertically joined compacted wooden boards in the width direction are joined to obtain several horizontally joined compacted wooden boards.

[0070] 8. In the sizing step, several horizontally joined compacted wooden boards are cut to size into several standard-length compacted boards using a woodworking breaker to obtain 48 shaku (4 shaku x 8 shaku) standard-length compacted boards (the dimensions of which are length, width, and thickness are 2440 mm * 1220 mm * 20 mm).

[0071] (Example 2) Manufacturing of standard size compacted plates This is basically the same as the first embodiment, but differs as follows. In the first preheating step, the temperature of the infrared irradiated space is 140°C. In the water layer application step, three water layer coaters each having one group of coating rollers are used to coat the water layer a total of three times.

[0072] (Example 3) Manufacturing of standard size compacted boards This is basically the same as the first embodiment, but differs as follows. In the first preheating step, the temperature of the infrared irradiated space is 150°C. In the water layer application step, three water layer coaters each having one group of coating rollers are used to coat the water layer a total of three times.

[0073] The water layer-attached cork strip is subjected to the high-frequency hot pressing step after the second preheating step, during which: In the second preheating step, several water-layered cork strips are irradiated with infrared light until the average temperature reaches 80-90°C.

[0074] (Example 4) Production of standard size compacted plates This is basically the same as the first embodiment, but differs as follows. In the vertical joining step, referring to the resin mixing material clamping method of embodiment 5, adjacent cooled compacted wooden boards in the longitudinal direction are joined to obtain several vertically joined compacted wooden boards, among which the vertical joining contact surfaces of the compacted wooden boards adjacent in the longitudinal direction of each vertically joined compacted wooden board are sawtooth surfaces. In the horizontal joining step, referring to the resin hot melt material clamping method of embodiment 6, adjacent vertically joined compacted wood boards in the width direction are joined to obtain several horizontally joined compacted wood boards, among which the horizontal joining contact surfaces of the adjacent compacted wood boards in the width direction of each horizontally joined compacted wood board are flat.

[0075] Two adjacent vertical joint contact surfaces or two adjacent horizontal joint contact surfaces are both pressed together by a PVB resin layer.

[0076] The steps for forming the vertically bonded PVB resin layer are as follows: In S1, the joint end surface of the compacted wooden board is processed into a sawtooth surface, In step S2, the PVB resin is hot-melted, and then 20-40 mesh PVB resin particles are added and stirred to obtain a PVB resin kneaded material. The PVB resin kneaded material is applied to the joint end surface (vertical joint contact surface) of the standard-length compacted wood, and the weight ratio of the PVB resin to the PVB resin particles is 8:1. In S3, the joint end faces of adjacent compacted wooden boards are pushed out by an air compaction device.

[0077] The steps for forming the PVB resin layer for horizontal bonding are as follows: In S1, the joint end surfaces of the compacted wooden boards are processed and shaped into a flat surface (if they are already flat, this step is omitted). In S2, the PVB resin is hot-melted to obtain a PVB resin hot-melt material, and the PVB resin kneaded material is applied to the joint end surface (lateral joint contact surface) with the standard-length compacted wood; In S3, the joint end faces of adjacent compacted wooden boards are pushed out by an air compaction device.

[0078] (Example 5) Production of standard size compacted plates This is basically the same as Example 4, but differs as follows. In the step of forming a vertical joining contact surface, In S1, the joint end surface of the compacted wooden board is processed into a sawtooth surface, In S2, the weight ratio of PVB resin to PVB resin particles is 10:1. In the step of forming a lateral joining contact surface, In S1, the joint end surfaces of the compacted wooden boards are processed and shaped into an inclined plane.

[0079] (Example 6) Production of standard size compacted plates This is basically the same as Example 4, but differs as follows. In the step of forming a vertical joining contact surface, In S1, the joint end surface of the compacted wooden board is processed into a sawtooth surface, In S2, the weight ratio of PVB resin to PVB resin particles is 12:1; In the step of forming a lateral joining contact surface, In S1, the joint end surfaces of the compacted wooden boards are processed and shaped into a flat surface.

[0080] (Example 7) Production of standard size compacted boards This is basically the same as Example 4, but differs as follows. In the high-frequency hot pressing step (three-combined pressing), the water layer-attached cork strip is subjected to heat compression and hardening treatment under high-frequency conditions in accordance with the method of embodiment 4 to obtain a three-combined pressed board with burrs. The front, back, left and right sides of the three-combined pressed board with burrs are trimmed using a square groove processing machine to obtain several compacted wood boards (also called three-combined pressed boards). In the lamination process, three water-coated cork strips are stacked in one direction to form a laminated wood board, and then 6-8 laminated wood boards are arranged in a matrix on the compaction plate / pallet of the hot press machine, with the direction of the force being the direct pressure direction.

[0081] The high frequency conditions were a compression speed of 25 seconds / time and a compression ratio of 25%.

[0082] (Example 8) Production of standard size compacted boards This is basically the same as Example 7, but differs as follows. The high frequency conditions were a compression speed of 27 seconds / time and a compression ratio of 30%.

[0083] (Example 9) Production of standard size compacted plates This is basically the same as Example 7, but differs as follows. The high frequency conditions were a compression speed of 30 seconds / time and a compression ratio of 28%.

[0084] (Example 10) Production of standard size compacted plates This is basically the same as Example 7, but differs as follows. In the cooling process, some of the densified wood boards are placed in a -130°C environment using liquid nitrogen freezing technology to cool to room temperature for 15 minutes, and then longitudinal joining is performed. Typically, some of the densified wood boards are cooled to room temperature using liquid nitrogen freezing technology and then removed from the liquid nitrogen freezer box. In other embodiments, "room temperature" refers to the temperature before longitudinal joining. For pipeline operations, the densified wood boards are cooled to a temperature of 3-5°C in a -130°C environment, and then sent out through the pipeline to enter the longitudinal joining equipment.

[0085] (Example 11) Production of standard compacted plates This is basically the same as Example 10, but differs as follows. In the cooling treatment step, some compacted wood boards are placed in a -140℃ environment using liquid nitrogen freezing technology to cool down to room temperature for 12 minutes, and then joined vertically.

[0086] (Example 12) Production of standard compacted plates This is basically the same as Example 10, but differs as follows. In the cooling treatment step, some compacted wood boards are placed in a -150℃ environment using liquid nitrogen freezing technology to cool to room temperature for 9 minutes, and then joined vertically.

[0087] (Comparative Example 1) Manufacturing of standard size compacted boards This is basically the same as Example 1, except that the water layer deposition step is omitted.

[0088] (Comparative Example 2) Manufacturing of standard size compacted boards This is basically the same as Example 1, except that the water layer attachment step is omitted and the first preheating step is changed to preheating with a high-frequency hot press.

[0089] (Comparative Example 3) Manufacturing of standard size compacted boards This is basically the same as the first embodiment, but differs as follows. In the first preheating step, the temperature of the infrared irradiation space is 160°C, and several preheated cork strips are obtained. In the water layer application step, the water layer coater equipped with the set of coating rollers is used to coat the water layer once in total.

[0090] (Comparative Example 4) Production of standard size compacted boards This is basically the same as Example 4, but differs as follows. In the step of forming a vertical joining contact surface, In S1, the joint end surface of the compacted wooden board is processed and formed into a flat surface. In the step of forming a lateral joining contact surface, In S1, the joint end surfaces of the compacted wooden boards are processed and shaped into an inclined plane.

[0091] (Comparative Example 5) Production of standard size compacted plates This is basically the same as Example 4, but differs as follows. In the step of forming a vertical joining contact surface, In S1, the joint end surface of the compacted wooden board is processed and formed into an inclined plane. In the step of forming a lateral joining contact surface, In S1, the joint end faces of the compacted wooden boards are processed and formed into sawtooth surfaces.

[0092] (Comparative Example 6) Production of standard size compacted boards This is basically the same as Example 4, but differs as follows. In the step of forming a vertical joining contact surface, In S2, the weight ratio of PVB resin to PVB resin particles is 14:1; In the step of forming a lateral joining contact surface, In S1, the joint end surfaces of the compacted wooden boards are processed and shaped into an inclined plane.

[0093] (Comparative Example 7) Production of standard size compacted boards This is basically the same as Example 7, but differs as follows. The high frequency condition is a compression speed of 40 seconds / cycle.

[0094] (Comparative Example 8) Production of standard compacted plates This is basically the same as Example 7, but differs as follows. The high frequency condition is a compression speed of 10 seconds / cycle.

[0095] (Comparative Example 9) Production of standard size compacted boards This is basically the same as Example 7, but differs as follows. The high frequency condition is a compression ratio of 20%.

[0096] The following tests are carried out with reference to the following examples and comparative examples.

[0097] (Test Example 1) Measurement of hairlines The wooden board is cut with a saw along the thickness direction to remove a 3 mm thick surface layer (the surface layer that is exposed to infrared radiation) to expose the inner layer, and the density and moisture content are measured.A total of six test pieces are then cut out: four at the corners and two in the center.

[0098] The dimensions of the test material are 150±1 mm in length and 50±0.5 mm in width.

[0099] The test method involves inspecting the hairline on the surface of the test material with normal vision (or corrected to normal vision) and a 6x magnifying glass at an illumination intensity of 800lx to 1000lx.

[0100] Regarding the hairline grade, grade 5 means there is no hairline, grade 4 means there is a hairline only with a 6x magnifying glass, and grade 3 means the hairline is observable with the naked eye. The hairline of one wooden board is the arithmetic average of the hairline grades of all test materials, approximated to an integer, and the results are shown in Table 1.

[0101] (Table 1) Hairline grade measurement results TIFF0007812578000001.tif70166

[0102] As can be seen from the test results, Examples 1-3 had significantly fewer hairlines than Comparative Examples 1-3. Water-layer-attached cork strips generate hot steam during high-frequency hot pressing, which can further alter the wood's properties. A comparison of Examples 1-3 with Comparative Example 2 shows that combining infrared preheating with high-frequency hot pressing of water-layer-attached cork strips produces essentially the same hairline grade as high-frequency preheating and hardening, but the former is more suitable for pipelines and less expensive, and is superior to the latter method of completing preheating using a high-frequency hot press. A comparison of Examples 1-3 with Comparative Examples 1 and 3 shows that infrared preheating or improper water layer attachment causes hairlines in the 2-4 mm surface layer of the poplar compacted board exposed to infrared radiation. As can be seen from Test Example 1, the methods of Examples 1-3 essentially solve this problem.

[0103] (Test Example 2) Flexural strength and flexural modulus test The method for determining bending strength is GB / T 1936.1-2009 "Testing Method for Bending Strength of Wood," and the method for determining bending modulus is GB / T 1936.2-2009 "Method for Measuring Bending Modulus of Wood." The test results are shown in Tables 2 and 3.

[0104] (Table 2) Bending strength test results TIFF0007812578000002.tif96166

[0105] (Table 3) Flexural modulus test results TIFF0007812578000003.tif96166

[0106] As can be seen from the test results, Examples 1 to 6 are superior in both bending strength and bending modulus compared to Comparative Examples 4 to 6. The bending strength and bending modulus performance of Examples 4 to 6 are even better. Thus, the triple compression method is more advantageous. As can be seen from a comparison between Examples 4 to 6 and Comparative Example 4, in the step of forming the vertical joining contact surface, the joining end surfaces of the compacted wood boards are processed into sawtooth surfaces, which increases the amount of resin carried, significantly improving the bending strength and bending modulus performance. As can be seen from a comparison between Examples 4 to 6 and Comparative Example 5, in the step of forming the horizontal joining contact surface, the joining end surfaces of the compacted wood boards are processed into sawtooth surfaces, but this does not significantly improve the bending strength and bending modulus performance. As can be seen from a comparison between Examples 4 to 6 and Comparative Example 6, in the step of forming the vertical joining contact surface, the weight ratio of PVB resin to PVB resin particles significantly affects the improvement of bending strength and bending modulus performance.

[0107] (Test Example 3) Screw gripping force test The method for detecting screw gripping force is GB / T 17657-2013 "Test methods for physicochemical performance of artificial boards and decoratively finished artificial boards," and the test results are shown in Table 4.

[0108] (Table 4) Screw gripping force test results TIFF0007812578000004.tif178166

[0109] As can be seen from the test results, the screw grip strength of Examples 4 to 9 is superior to that of medium-density board, fine wood board, and general particle board. The screw grip strength of Examples 7 to 9 is similar to that of textured board that can be finished. The screw grip strength of Examples 4 to 9 on the board sides is basically the same, but the screw grip strength of Examples 7 to 9 at the board joints is superior to that of Examples 4 to 6. As can be seen from a comparison between Examples 4 to 6 and Examples 7 to 9, there is no significant difference in the compression speed and compression ratio.

[0110] (Test Example 4) Measurement of formaldehyde content The criteria for formaldehyde (mg / L) are in accordance with GB 18584-2001 "Limits of Harmful Substances in Wooden Furniture Interior Construction Materials," and the test results are shown in Table 5.

[0111] (Table 5) Formaldehyde test results TIFF0007812578000005.tif83166

[0112] The test results show that Examples 1, 4, 7 and 10 all meet the requirements for formaldehyde in GB 18584-2001 "Limits of Harmful Substances in Wooden Furniture Interior Construction Materials".

[0113] (Test Example 5) Measurement of Accelerated Aging Performance 1. After the test material is cycled six times by immersion in hot water - spray evaporation - freezing - drying - spray evaporation - drying, the screw gripping force and water absorption thickness expansion rate of the test material are measured.

[0114] 2. The equipment used is a steam accelerated aging test box for artificial boards, which meets the requirements for equipment in "Measurement of accelerated aging performance" in GB / T 17657-2013 "Test methods for the physical and chemical properties of artificial boards and decoratively finished artificial boards."

[0115] 3. Dimensions of test material The dimensions of the static bending strength test material are (length 450±1mm, width 50±1mm, thickness 20±1mm), The dimensions of the screw gripping force test material are (length 75±1mm, width 50±1mm, thickness 20±1mm), The dimensions of the water absorption thickness swelling test material are (length 50±1 mm, width 50±1 mm).

[0116] 4. Balancing of test materials The test material is placed in an environment of 20±2°C and a relative humidity of 65±5% until it reaches the specified mass (weigh it twice every 24 hours, and the mass is considered to be specified if the difference in mass between the two weighings is less than 1% of the mass of the consolidated material).

[0117] 5. Test Method In the accelerated aging cycle, the test material is subjected to six cycles, each cycle including the following steps: a) The test material is immersed in warm water at (49±2)°C for 1 hour. b) The test material is sprayed and evaporated in steam at (93±3)°C for 3 hours. c) The test material is frozen in a freezer at (-12±3)℃ for 20 hours. d) The test material is dried in a ventilation drying box at (99±2)°C for 3 hours. e) The test material is sprayed and evaporated in steam at (93±3)°C for 3 hours. f) The test material is dried in a ventilation drying box at (99±2)℃ for 18 hours.

[0118] After all six cycles of accelerated aging tests were completed, the test materials were placed at (20±2)°C and a relative humidity of (65±5)% for at least 48 hours, followed by performance testing. The test results are shown in Table 6.

[0119] Table 6: Accelerated aging performance measurements TIFF0007812578000006.tif83166

[0120] As can be seen from the test results, after accelerated aging, the screw grip strength of Examples 4, 7, and 10 all decreased, but was still superior to or comparable to that of medium-density board, fine wood board, and general particle board. Examples 7 and 10 had lower water absorption thickness swelling rates than Example 4, thus demonstrating the structural rebound prevention performance of the triple compression technology. Example 10 had the lowest water absorption thickness swelling rate, indicating that quenching rebound prevention and structural rebound prevention performance can work synergistically.

[0121] Although the present invention has been described in detail above through the general description, specific embodiments and tests, it is obvious to those skilled in the art that some modifications or improvements can be made based on the present invention. Therefore, any modifications or improvements made without departing from the spirit of the present invention are included in the scope of the claims for protection of the present invention.

Claims

1. The fixed-length compacted board comprises several longitudinally joined compacted wooden boards connected in the width direction, each longitudinally joined compacted wooden board comprises several laminated compacted wooden board strips connected in the length direction, each laminated compacted wooden board strip comprises three-layered cork board strips connected in the thickness direction by a high-frequency hot pressing step; The vertical joint patterns of adjacent vertically joined compacted wood boards are not on the same straight line. The manufacturing process for the fixed-length compacted board is as follows: a cork slab manufacturing step of manufacturing standard-sized poplar slabs having a length of 50 cm to 120 cm and a width of 22 cm or 44 cm to obtain the cork slabs; a first preheating step in which a plurality of cork slabs with a moisture content of 10% to 20% are heated by infrared radiation in an infrared preheating box until the average temperature reaches 80 to 90°C, thereby obtaining a plurality of preheated cork slabs, wherein in the first preheating step, the infrared radiation is applied in an infrared radiation space whose temperature is 130 to 150°C; a water layer applying step in which a water layer is applied to the surface of the preheated cork slab irradiated with infrared light by a water layer applying machine to obtain several water layer-applied cork slabs; a step of hot pressing the water layer-attached cork boards after laminating them, and then immediately performing a heat compression and hardening process under high frequency conditions to obtain a plurality of laminated compacted wood boards, wherein the compression ratio under the high frequency conditions is 25%, 28% or 30%; A cooling step in which the plurality of laminated and compressed wood boards are cooled until the average temperature of the wood reaches 70 to 90°C or 3 to 5°C; The longitudinal joining step involves joining longitudinally adjacent cooled laminated densified wood boards to obtain several longitudinally joined densified wood boards, in which the longitudinal joint contact surfaces of adjacent densified wood boards in each longitudinally joined densified wood board are sawtooth surfaces, and two adjacent longitudinal joint contact surfaces are connected by a PVB resin layer to form a longitudinally joined PVB resin layer. The steps are as follows: S1: Process the joint end surfaces of the densified wood boards into sawtooth surfaces; S2: Hot-melt PVB resin, add 20-40 mesh PVB resin particles and stir to obtain a PVB resin mixture, which is then applied to the longitudinal joint contact surfaces of the densified wood boards, with the weight ratio of PVB resin to PVB resin particles being 8:1; S3: Extrude the joint end surfaces of adjacent densified wood boards using an air compaction device; The horizontal joining step of joining adjacent longitudinally joined compacted wood boards in the width direction to obtain several horizontally joined compacted wood boards, in which the horizontal joint contact surfaces of adjacent compacted wood boards in the width direction of each horizontally joined compacted wood board are flat, and two adjacent horizontal joint contact surfaces are connected by a PVB resin layer, forming the horizontally joined PVB resin layer, is as follows: in SS1, the joint end surfaces of the compacted wood boards are processed into a flat surface; in SS2, the PVB resin is hot-melted to obtain a PVB resin hot-melt material, and the PVB resin mixed material is applied to the horizontal joint contact surfaces with the standard-length compacted wood; in SS3, the joint end surfaces of adjacent compacted wood boards are extruded using an air compacting device; A high frequency-based process for manufacturing standard-sized compacted boards, comprising: a sizing step of cutting several transversely bonded compacted wood boards to standard-sized compacted boards.

2. The water layer-attached cork strip is subjected to a second preheating step and then to the high-frequency hot pressing step, during which: The process for producing compacted boards of standard length as described in claim 1, characterized in that in the second preheating step, some of the water layer-attached cork boards are irradiated with infrared rays to maintain an average temperature of 80 to 90°C.

3. The manufacturing process for a standard compacted board according to claim 2, characterized in that in the water layer application step, water is applied to the surface of the preheated cork strip 1 to 4 times.

Images