A method for manufacturing a whole sheet veneer-based panel

Abstract

The application discloses a manufacturing method of whole veneer artificial board based on non-woven paper, and belongs to the technical field of artificial board processing. In view of the technical defects of the existing veneer artificial board production process, such as complicated process, low production efficiency, high processing cost, poor overall performance of the board, low splicing strength, easy cracking and deformation and the like, the application adopts a non-woven paper physical compounding and whole veneer process, discards the traditional horizontal joint and longitudinal joint process, firstly carries out accurate paving and positioning through a robot, then realizes physical fixation of the whole veneer by paving the non-woven paper with the same plane on the veneer surface layer, and finally prepares the whole veneer artificial board through gluing, assembly, hot pressing and curing forming. The application simplifies the whole veneer processing flow, greatly improves the whole veneer processing efficiency, reduces the production and labor costs, and effectively improves the overall structural stability, anti-deformation capability and board surface flatness of the finished artificial board, and is suitable for large-scale production of various large-plane veneer artificial boards.

Description

Technical Field

[0001] This invention belongs to the field of engineered wood processing technology, and relates to a method for manufacturing a sheet-fed engineered wood panel based on non-woven paper. Background Technology

[0002] Veneer is the core material in the production of engineered wood products, and it is widely used in the processing and manufacturing of various wood-based engineered wood products such as plywood, veneer, and blockboard. Due to limitations in logging and rotary cutting processes, veneers obtained through conventional processing are mostly narrow and small in size, which cannot directly meet the production requirements of 4×8-foot large-format engineered wood products. Therefore, it is necessary to process small-format veneers into whole sheets to prepare large-format whole veneers before they can be used for subsequent engineered wood product forming and processing.

[0003] Currently, the mainstream single-sheet processing methods in the industry are mainly horizontal splicing or vertical finger jointing. Among them, the horizontal splicing process requires trimming, aligning, splicing, and gluing multiple small-format veneers, which is a complicated process that requires manual assistance for alignment and trimming, resulting in low automation. The vertical finger jointing process requires milling, gluing, and butt joint curing at the ends of the veneers, which requires a large investment in processing equipment and a long processing cycle.

[0004] In summary, existing technologies have several inherent drawbacks: First, the processing steps are numerous and cumbersome, resulting in low production efficiency and an inability to meet the demands of large-scale, high-efficiency production lines. Second, the high degree of manual intervention leads to poor alignment accuracy, low product consistency, and a high defect rate. Third, structural gaps and stress concentrations exist at splicing and finger-jointing points, making finished boards prone to cracking, warping, deformation, and poor surface flatness. Fourth, the high costs of processing auxiliary materials, labor, and equipment maintenance significantly increase the total production cost of engineered wood products, hindering the industry's development towards efficient and low-cost production.

[0005] Therefore, there is an urgent need to develop a simple, efficient, low-cost, and high-quality veneer sheet processing method to address the technical pain points of existing veneer sheet processing technologies. Summary of the Invention

[0006] To address the problems of cumbersome, inefficient, and costly processes such as veneer splicing and finger jointing in existing technologies, as well as the tendency of finished boards to deform and crack, the present invention aims to provide a method for manufacturing sheet-based engineered wood panels using non-woven paper. This method simplifies processing steps, improves production efficiency, reduces production costs, and significantly enhances the structural stability and surface quality of sheet-based veneers and engineered wood panels.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper includes the following steps: (1) Precise installation and positioning: Select qualified small-size veneers, transport them to a special processing workbench, and use automated installation equipment to complete the installation of preset standard-size veneers. The visual positioning correction system on the automated installation equipment is used to align and correct the corners of the veneers, so as to achieve precise alignment without misalignment or offset, and form a regular veneer substrate. (2) Physical fixation of non-woven paper sheet: Non-woven paper matching the preset standard size is laid on the surface of the veneer substrate in step (1). The non-woven paper is physically fixed to the veneer substrate. The integrity, flexibility and tensile properties of the non-woven paper are used to integrate the scattered small-size veneers into an integrated veneer blank. (3) Glue application and blanking process: Apply glue evenly to the surface of the integral sheet veneer blank from step (2), and stack the blanks according to the thickness and performance requirements of the target integral sheet veneer artificial board to obtain the blank. (4) Hot pressing and curing: The blank from step (3) is sent into a hot pressing device, and the adhesive layer is cured and the board is compacted by hot pressing. After natural cooling or air cooling, a whole sheet of veneer artificial board is obtained.

[0008] Preferably, in step (1), the small-format veneer is a solid wood rotary-cut veneer; the thickness of the small-format veneer is 0.6 to 3.0 mm, and the moisture content is controlled at 8% to 12%.

[0009] As a further preferred option, the thickness of the small-format veneer is 1.5–2.0 mm.

[0010] Preferably, in step (1), the automated paving equipment is a paving robot equipped with a visual positioning correction system; the preset standard size is 4×8 feet; the alignment correction accuracy is controlled within ±3mm; and the flatness error of the single-layer substrate is ≤3mm / m.

[0011] Preferably, in step (2), the nonwoven paper is any one or more composite structures selected from polyester nonwoven paper, wood pulp nonwoven paper, and plant fiber nonwoven paper; the basis weight of the nonwoven paper is 30-120 g / m³. 2 The air permeability of the nonwoven paper is ≥80mm / s, and the longitudinal tensile strength is ≥200N / 5cm.

[0012] As a further preferred embodiment, the nonwoven paper is polyester nonwoven paper; the basis weight of the nonwoven paper is 80-100 g / m³. 2 .

[0013] Preferably, in step (2), the nonwoven paper is laid in a single-sided or double-sided reinforced manner.

[0014] As a further preferred embodiment, the single-sided reinforcement is applied only to the upper or lower surface of the veneer substrate; the double-sided reinforcement is applied simultaneously to both the upper and lower surfaces of the veneer substrate.

[0015] As a preferred option, in step (2), the physical fixing method is: first, use an automated air gun installed on the paving robot for fixing, and then use a roller pressing process or a flat pressing process for compaction.

[0016] As a further preferred option, when using a roll forming process, the roll forming pressure is 0.2 to 0.6 MPa and the roll forming speed is 5 to 15 m / min.

[0017] More preferably, when using a rolling process, the rolling pressure is 0.4 to 0.5 MPa and the rolling speed is 8 to 10 m / min.

[0018] Preferably, in step (3), the adhesive application method is any one of roller coating, spraying, or curtain coating; the amount of adhesive applied is controlled at 120-180 g / m³. 2 The adhesive used in the sizing process is any one of melamine-modified urea-formaldehyde resin adhesive, isocyanate adhesive, or phenolic resin adhesive.

[0019] As a further preferred embodiment, the amount of adhesive applied is controlled at 140–160 g / m³. 2 .

[0020] Preferably, in step (3), the stacking method of the billet assembly is single-layer stacking or multi-layer stacking. The stacking process must strictly ensure the alignment between layers, without offset, wrinkles, or hollow areas.

[0021] As a preferred option, in step (4), the parameters of the hot pressing process are: hot pressing temperature of 120-160℃, hot pressing pressure of 1.2-2.5MPa, and hot pressing time of 0.8-1.5min / mm based on the thickness of the whole sheet of veneer artificial board.

[0022] As a further preferred option, the parameters for the hot pressing process are: hot pressing temperature of 145-150℃, hot pressing pressure of 1.8-2.2MPa, and hot pressing time of 0.8-1.5min / mm based on the thickness of the whole sheet of veneer artificial board.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention abandons the cumbersome processes of traditional single-board splicing, finger splicing, edge trimming, milling, seam splicing, and curing. It adopts automated laying equipment to replace the traditional manual splicing and alignment process, and combines non-woven paper physical sheeting process to achieve single-board sheeting in one step. The process is greatly simplified, the degree of automation is high, and the production efficiency is greatly improved compared with the traditional process, making it suitable for large-scale assembly line production.

[0024] (2) The method of the present invention effectively reduces the degree of manual involvement and reduces labor costs; it also eliminates the need for special splicing and finger splicing equipment, reducing equipment investment and maintenance costs; it eliminates splicing gap waste, cutting waste and greatly improves the utilization rate of raw materials, significantly reducing the overall production cost.

[0025] (3) The present invention adopts the physical sheet forming process of non-woven paper, which effectively improves the forming quality and stability of the board. Non-woven paper has good tensile strength, crack resistance and flexibility, which can form an overall constraint on the single board, eliminate the gap defects and stress concentration problems of traditional splicing and finger joint processes, effectively avoid cracking, warping and deformation of finished boards, greatly improve the flatness of the board surface and the overall structural strength of the board, and make the product more consistent.

[0026] (4) This invention can be adapted to solid wood veneers of different thicknesses and materials, and can achieve single-sided and double-sided non-woven paper reinforcement. It can meet the production needs of artificial boards of different thicknesses and different usage scenarios. It has wide process adaptability and high industrial application value. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the longitudinal laying of nonwoven paper and veneer substrate in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the horizontal laying of non-woven paper and veneer substrate in Embodiment 1 of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The automated paving equipment used in this invention is a paving robot equipped with a visual positioning correction system; the air permeability of the non-woven paper used in this invention is ≥80mm / s, and the longitudinal tensile strength is ≥200N / 5cm.

[0030] The laying direction of the nonwoven paper and the veneer substrate in this invention is as follows: Figure 1 (Longitudinal paving) and Figure 2(Horizontal Laying) As shown: When horizontal laying is used, the fiber direction of the non-woven paper is parallel to the fiber direction of the veneer substrate. The laying method is as follows: the veneer substrate is transported to a special processing workbench, and the laying robot equipped with a vision positioning correction system completes the automated laying and positioning. When vertical laying is used, the fiber direction of the non-woven paper is perpendicular to the fiber direction of the veneer substrate. The laying method is as follows: the veneer substrate is transported to a special processing workbench, and the laying robot equipped with a vision positioning correction system performs automatic identification and rapid cutting. Then, the "L-shaped" steering mechanism rotates the cut small-format veneer by 90 degrees and transports it forward, finally completing the automated laying and positioning.

[0031] Example 1 A method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper includes the following steps: (1) Precise installation and positioning: Select poplar rotary-cut veneer with a thickness of 1.5mm and a moisture content of 10%, transport the poplar rotary-cut veneer to a special processing workbench, and complete the automated installation and positioning of 4×8-foot veneer by an installation robot equipped with a vision positioning and correction system. The accuracy of the alignment correction is controlled within ±1mm, and the surface of the 4×8-foot veneer substrate after installation is flat and without misalignment.

[0032] (2) Physical fixation of nonwoven paper sheets: Select a basis weight of 80 g / m 2 Furthermore, the polyester nonwoven paper, which is compatible with the 4×8 size, is laid on the surface of the veneer substrate using a single-sided reinforcement method. It is first fixed with an automated air gun, and then compacted with a roller pressing process (roller pressing pressure 0.4MPa, roller pressing speed 10m / min), so that the nonwoven paper and the veneer substrate are tightly bonded together without any air gaps or separation, resulting in an integrated sheet veneer blank.

[0033] (3) Adhesive application and preform treatment: Melamine-modified urea-formaldehyde resin adhesive is selected, and the amount of adhesive applied is controlled at 150g / m². 2 The roller coating method is used to uniformly apply glue to the surface of the integrated sheet veneer blank. Then, according to the thickness requirements of the target integrated sheet veneer artificial board, three layers of blanks are stacked to ensure that the layers are aligned and there is no misalignment.

[0034] (4) Hot pressing and curing: The blank after the assembly in step (3) is sent to the hot press for processing. The hot pressing temperature is set to 120℃, the hot pressing pressure is 2.0MPa, and the hot pressing time is 1.2min / mm. After the hot pressing is completed, it is cooled to room temperature by air cooling and shaped to obtain a whole sheet of veneer artificial board.

[0035] Example 2 A method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper includes the following steps: (1) Precise installation and positioning: Select poplar rotary-cut veneer with a thickness of 2.0mm and a moisture content of 11%, transport the poplar rotary-cut veneer to a special processing workbench, and complete the automated installation and positioning of 4×8-foot veneer by an installation robot equipped with a vision positioning and correction system. The accuracy of the alignment correction is controlled within ±1mm, and the surface of the 4×8-foot veneer substrate after installation is flat and without misalignment.

[0036] (2) Physical fixation of nonwoven paper sheets: Select a weight of 100g / m 2 Furthermore, the wood pulp nonwoven paper, which is compatible with the 4×8 size, is laid on both the upper and lower surfaces of the veneer substrate using a double-sided reinforcement method. First, it is fixed with an automated air gun, and then double-sided compaction is carried out using a roller pressing process (roller pressing pressure 0.5MPa, roller pressing speed 8m / min), so that the nonwoven paper and the veneer substrate are tightly bonded together without any air gaps or separation, resulting in an integrated sheet of veneer blank.

[0037] (3) Adhesive application and preform preparation: Phenolic resin adhesive is selected, and the amount of adhesive applied is controlled at 160g / m². 2 The surface of the integrated sheet veneer blank is uniformly coated with adhesive using a spraying method. Then, five layers of blanks are stacked according to the thickness requirements of the target integrated sheet veneer artificial board to ensure that the layers are aligned without misalignment.

[0038] (4) Hot pressing and curing: The blank after the assembly in step (3) is sent to the hot press for processing. The hot pressing temperature is set to 160℃, the hot pressing pressure is 2.2MPa, and the hot pressing time is 1.0min / mm. After the hot pressing is completed, it is naturally cooled to room temperature and shaped to obtain a whole sheet of veneer artificial board.

[0039] Example 3 A method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper includes the following steps: (1) Precise installation and positioning: Select poplar rotary-cut veneer with a thickness of 0.6mm and a moisture content of 8%, transport the poplar rotary-cut veneer to a special processing workbench, and complete the automated installation and positioning of 4×8-foot veneer by an installation robot equipped with a vision positioning and correction system. The accuracy of the alignment correction is controlled within ±1mm, and the surface of the 4×8-foot veneer substrate after installation is flat and without misalignment.

[0040] (2) Physical fixation of nonwoven paper sheets: Select a weight of 120g / m 2 Furthermore, the composite structure of polyester nonwoven paper and wood pulp nonwoven paper, which are compatible with the 4×8 size, is reinforced on one side. The polyester nonwoven paper is laid on the surface of the veneer substrate. First, it is fixed with an automated air gun, and then it is compacted with a roller pressing process (roller pressing pressure 0.2MPa, roller pressing speed 15m / min). This ensures that the nonwoven paper and the veneer substrate are tightly bonded, without any air gaps or separation, resulting in an integrated sheet veneer blank.

[0041] (3) Adhesive application and preform treatment: Melamine-modified urea-formaldehyde resin adhesive is selected, and the amount of adhesive applied is controlled at 180g / m². 2 The roller coating method is used to uniformly apply glue to the surface of the integrated sheet veneer blank. Then, according to the thickness requirements of the target integrated sheet veneer artificial board, three layers of blanks are stacked to ensure that the layers are aligned and there is no misalignment.

[0042] (4) Hot pressing and curing: The blank after the assembly in step (3) is sent to the hot press for processing. The hot pressing temperature is set to 145℃, the hot pressing pressure is 1.2MPa, and the hot pressing time is 0.8min / mm. After the hot pressing is completed, it is cooled to room temperature by air cooling and shaped to obtain a whole sheet of veneer artificial board.

[0043] Example 4 A method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper includes the following steps: (1) Precise installation and positioning: Select poplar rotary-cut veneer with a thickness of 3.0mm and a moisture content of 12%. The poplar rotary-cut veneer is transported to a special processing workbench. The small-format veneer after cutting is rotated 90 degrees by an "L-shaped" steering mechanism. The 4×8-foot veneer is automatically installed and positioned by an installation robot equipped with a visual positioning correction system. The accuracy of the alignment correction is controlled within ±1mm. The surface of the 4×8-foot veneer substrate after installation is flat and without misalignment.

[0044] (2) Physical fixation of nonwoven paper sheets: Select a weight of 30g / m 2 Furthermore, the wood pulp nonwoven paper, which is compatible with the 4×8 size, is laid on the surface of the veneer substrate using a single-sided reinforcement method. First, it is fixed with an automated air gun, and then compacted with a roller pressing process (roller pressing pressure 0.6MPa, roller pressing speed 5m / min), so that the nonwoven paper and the veneer substrate are tightly bonded together without any air gaps or separation, resulting in an integrated sheet veneer blank.

[0045] (3) Adhesive application and preform treatment: Melamine-modified urea-formaldehyde resin adhesive is selected, and the amount of adhesive applied is controlled at 120g / m². 2 The roller coating method is used to uniformly apply glue to the surface of the integrated sheet veneer blank. Then, according to the thickness requirements of the target integrated sheet veneer artificial board, three layers of blanks are stacked to ensure that the layers are aligned and there is no misalignment.

[0046] (4) Hot pressing and curing: The blank after the assembly in step (3) is sent to the hot press for processing. The hot pressing temperature is set to 150℃, the hot pressing pressure is 2.5MPa, and the hot pressing time is 1.5min / mm. After the hot pressing is completed, it is cooled to room temperature by air cooling and shaped to obtain a whole sheet of veneer artificial board.

[0047] Comparative Example 1 The difference between this comparative example and Example 1 is that the traditional single-board splicing process is used, while the remaining steps and parameters are the same as in Example 1, as detailed below: (1) Manual trimming and finger jointing: Poplar veneer with a thickness of 1.5 mm and a moisture content of 10% was selected. Traditional manual trimming process was adopted, and the four sides of the veneer were trimmed according to the finished product size standard to remove edge burrs and excess material, ensuring that the veneer surface was flat and the dimensions were regular. Then, manual alignment and calibration were performed to correct veneer warping and misalignment, and the splicing gaps were straightened. The veneer selection and positioning accuracy standards were consistent with those in Example 1.

[0048] (2) Adhesive application and preform preparation: Melamine-modified urea-formaldehyde resin adhesive is selected, and the amount of adhesive applied is controlled at 150g / m². 2 The veneer blanks are uniformly coated with adhesive using a roller coating method. Then, three layers of blanks are stacked according to the thickness requirements of the target plywood to ensure that the layers are aligned without misalignment.

[0049] (3) Hot pressing and curing: The blank after step (2) is sent to the hot press for processing. The hot pressing temperature is set to 120℃, the hot pressing pressure is 2.0MPa, and the hot pressing time is 1.2min / mm. After the hot pressing is completed, it is cooled to room temperature by air cooling and shaped to obtain plywood.

[0050] Tests showed that the production efficiency of this comparative example was much lower than that of Example 1. The joints of the boards were prone to cracking, the flatness of the board surface was poor, the defect rate was more than 15% higher, and the overall production cost was about 20% higher.

[0051] Compared with Comparative Example 1, the monolithic veneer engineered wood panels prepared in Examples 1, 2, 3, and 4 of this invention have no splicing gaps, significantly improved surface flatness, and significantly enhanced resistance to deformation and cracking. The production process is reduced by 60%, labor costs are reduced by more than 50%, production efficiency is increased by 40%–50%, and raw material utilization rate is increased to more than 98%, resulting in significant overall economic benefits.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper, characterized in that, Includes the following steps: (1) Precise installation and positioning: Select qualified small-format veneers, use automated installation equipment to complete the installation and alignment of the preset standard-format veneers, and process the small-format veneers into regular veneer substrates; (2) Physical fixation of non-woven paper sheet: Non-woven paper matching the preset standard size is laid on the surface of the veneer substrate in step (1). The non-woven paper is physically fixed to the veneer substrate, and the scattered small-size veneers are integrated into a whole sheet of veneer blank using non-woven paper. (3) Glue application and blanking process: Apply glue evenly to the surface of the integral sheet veneer blank from step (2), and stack the blanks according to the thickness and performance requirements of the target integral sheet veneer artificial board to obtain the blank; (4) Hot pressing and curing: The board blank of step (3) is processed by hot pressing process to complete the curing of the adhesive layer and the compacting of the board. After cooling and shaping, a whole sheet of veneer artificial board is obtained.

2. The method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper according to claim 1, characterized in that, In step (1), the small-format veneer is a solid wood rotary-cut veneer; the thickness of the small-format veneer is 0.6 to 3.0 mm, and the moisture content is controlled at 8% to 12%.

3. The method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper according to claim 1, characterized in that, In step (2), the nonwoven paper is any one or more composite structures selected from polyester nonwoven paper, wood pulp nonwoven paper, and plant fiber nonwoven paper; the basis weight of the nonwoven paper is 30-120 g / m³. 2 .

4. The method for manufacturing a single-sheet veneer engineered wood panel based on nonwoven paper according to claim 1, characterized in that, In step (2), the nonwoven paper is laid in a single-sided or double-sided reinforcement manner.

5. The method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper according to claim 4, characterized in that, The single-sided reinforcement is applied only to the upper or lower surface of the veneer substrate; the double-sided reinforcement is applied simultaneously to both the upper and lower surfaces of the veneer substrate.

6. The method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper according to claim 1, characterized in that, In step (2), the physical fixing method is: first, use an automated air gun to fix it, and then use a roller pressing process or a flat pressing process to compact it.

7. The method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper according to claim 6, characterized in that, When using the roll forming process, the roll forming pressure is 0.2 to 0.6 MPa and the roll forming speed is 5 to 15 m / min.

8. The method for manufacturing a single-sheet veneer engineered wood panel based on nonwoven paper according to claim 1, characterized in that, In step (3), the adhesive application method is any one of roller coating, spraying, or curtain coating; the amount of adhesive applied is controlled at 120-180 g / m³. 2 The adhesive used in the sizing process is any one of melamine-modified urea-formaldehyde resin adhesive, isocyanate adhesive, or phenolic resin adhesive.

9. The method for manufacturing a sheet-fed engineered wood panel based on nonwoven paper according to claim 1, characterized in that, In step (4), the parameters of the hot pressing process are: hot pressing temperature is 120~160℃, hot pressing pressure is 1.2~2.5MPa, and hot pressing time is 0.8~1.5min / mm based on the thickness of the whole sheet of veneer artificial board.

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