Manufacturing method of laminated oriented batten bearing type bamboo-wood composite material

Abstract

The manufacturing method of the laminated directional batten bearing type bamboo-wood composite material comprises the following steps: (1) preparing raw materials; the whole chordwise bamboo strip mat, the radial bamboo strip curtain, the directional battens and the wood veneers are prepared according to process requirements, and wear-resistant layer materials are selected. And (2) paving a plate blank. And paving the whole-piece wood veneer, the non-whole-piece wood veneer, the radial bamboo split curtain, the directional batten, the radial bamboo split curtain, the non-whole-piece wood veneer, the whole chordwise bamboo split mat and the wear-resistant layer in sequence from bottom to top. And (3) hot press molding. The hot press can be an intermittent single-layer hot press or an intermittent multi-layer hot press; the hot pressing mode is a'cold feeding-cold discharging 'hot pressing forming process, namely the procedures of'feeding, heating, heat preservation and hot pressing, cooling and pressure relief and discharging'; the hot pressing process is divided into three stages, namely pressure boosting, pressure maintaining and unloading, in the pressure maintaining stage, the unit pressure of a press is 1.5-8Mpa, and the temperature of a hot pressing plate is 140-220 DEG C. And (4) longitudinally and transversely cutting edges to be processed into specification materials. And the thickness is 15-40mm, the common breadth is 1220 * 2440mm, and a specific breadth can be made as required. The bamboo-wood composite board has the advantages that bamboo wood and wood are used as main raw materials, leftover materials obtained through wood processing are combined, the physical and mechanical properties of the product are better than those of natural wood boards or other wood-based artificial board materials, and the bamboo-wood composite board can be widely applied to vehicle and ship bottom boards, container bottom boards and boards in other load-bearing occasions.

Description

Technical Field

[0001] This invention relates to a method for manufacturing bamboo-wood composite materials, and more particularly to a method for manufacturing a laminated oriented oriented wood strip-supported bamboo-wood composite material. Background Technology

[0002] Currently, composite boards produced using plant fibers both domestically and internationally include particleboard, MDF / HDF (medium-density fiberboard / high-density fiberboard), plywood, and other scrap boards. These composite materials are mainly used in non-load-bearing applications such as furniture manufacturing and building decoration. However, there is an urgent need for load-bearing composite materials in fields such as building structures, container manufacturing, and vehicle and ship manufacturing.

[0003] Due to the unique microstructure of bamboo, such as its hollow, tapered shape, green bamboo, bamboo nodes, and yellow bamboo, bamboo strips have advantages such as high tensile strength and high toughness, making them a possible raw material for manufacturing laminated oriented load-bearing bamboo-wood composite materials.

[0004] Bamboo belongs to the Bambusoideae subfamily of grasses and is mainly distributed in tropical and subtropical regions. China is one of the countries with the richest bamboo resources in the world, with bamboo distributed in Fujian, Zhejiang, Hunan, Jiangxi, Anhui, Sichuan, Yunnan, Guangdong and other places. Bamboo is not only not limited by forest resource harvesting, but also has a fast growth rate. Taking moso bamboo, which has the largest proportion of timber bamboo in China, as an example, it can be harvested in 3-5 years. Vigorously developing bamboo-wood composite materials can effectively save timber resources. Summary of the Invention

[0005] The purpose of this invention is to provide a method for manufacturing a load-bearing laminated oriented strand board (OOSB) bamboo-wood composite material. This method uses bamboo and wood as the main raw materials, and the resulting OOSB composite material exhibits superior physical and mechanical properties compared to natural wood panels or other wood-based engineered wood products. The product of this invention can be widely used in vehicle and ship flooring, container flooring, and other load-bearing applications.

[0006] The laminated oriented strand board (OSB) bamboo-wood composite material of this invention consists of eight layers, from top to bottom: a wear-resistant layer, a whole sheet of tangential bamboo strips, a non-whole sheet of veneer, a radial bamboo curtain, oriented strand boards, radial bamboo curtain, non-whole sheet of veneer, and whole sheet of veneer. The material thickness is 15~40mm, and the commonly used size is 1220×2440mm, but it can also be made into specific sizes as needed.

[0007] To achieve the above objectives, the manufacturing method of the laminated oriented strand wood load-bearing bamboo-wood composite material of the present invention includes the following steps: (1) Material preparation process 1) Preparation, impregnation, and drying of whole tangential bamboo mats Bamboo sections are split into arc-shaped bamboo blanks. These blanks are then split into tangential strips using a tangential splitting machine. These strips are then woven into bamboo mats using a bamboo mat weaving machine. The bamboo mats are then soaked in a glue-impregnating tank. Finally, the glue-impregnated bamboo mats are dried in a drying machine. Specific process parameters: Tangential strips: width 5~25mm, thickness 0.1~1.5mm.

[0008] Impregnation amount: adhesive solids: dry bamboo strips (weight ratio) = (3~12):100.

[0009] Adhesives: MDI, PF, UF or other adhesives used in the wood-based panel industry.

[0010] The moisture content of dried bamboo mats is 2% to 8%.

[0011] 2) Preparation, impregnation, and drying of radial bamboo blinds Bamboo sections are split into arc-shaped bamboo blanks. These blanks are then split into radial strips using a radial splitting machine. The radial strips are then woven into bamboo curtains using a bamboo curtain weaving machine. The bamboo curtains are then immersed in a resin-impregnating tank to absorb the resin. Finally, the resin-impregnated bamboo curtains are dried in a drying machine. Specific process parameters: Radial strips: width equal to the natural wall thickness of the bamboo tube, thickness 0.5~5.0mm.

[0012] Impregnation amount: adhesive solids: dry bamboo strips (weight ratio) = (3~12):100.

[0013] Adhesives: MDI, PF, UF or other adhesives used in the wood-based panel industry.

[0014] The moisture content of dried bamboo mats is 2% to 8%.

[0015] 3) Preparation, drying, and gluing of oriented wood strips Logs are oriented stranded wood (OSW) strips made using a slicing machine or by shearing rotary veneer. The OSW strips are then dried and mixed with or sprayed with adhesive using a glue mixer. To conserve timber resources, small-diameter logs or wood processing scraps such as veneer chips can be used for OSW strip production. Specific process parameters: Oriented wood strips: length 150~200mm, width 15~20mm, thickness ≤4.0mm.

[0016] Glue application rate: Solid amount of adhesive: Dry wood strips (weight ratio) = (3~12):100.

[0017] Adhesives: MDI, PF, UF or other adhesives used in the wood-based panel industry.

[0018] Moisture content of oriented wood strips after gluing: 2%~12%.

[0019] 4) Wood veneer preparation, drying, and gluing Logs are veneered using a veneer veneer cutting machine. Large-format veneers are spliced ​​together to form whole sheets of chemically treated veneer, while small-format veneers are spliced ​​together to form non-whole sheets of chemically treated veneer. The remaining veneer fragments can be used to prepare wood strips. The whole and non-whole sheets of chemically treated veneer are dried and then coated with glue using a glue applicator. Specific process parameters: Single-layer thickness: ≤4.0mm.

[0020] Whole sheet of wood veneer: The common size is 1220×2440mm, but it can also be made into a specific size as needed.

[0021] Non-sheet wood veneer: made into a certain size as needed.

[0022] Glue application amount: Adhesive solids: Oven-dry veneer weight (weight ratio) = (3~12):100.

[0023] Adhesives: MDI, PF, UF or other adhesives used in the wood-based panel industry.

[0024] Moisture content of veneer after gluing: 2%~12%.

[0025] 5) Select wear-resistant layer material Choose durable paper or other materials with adhesive backing available on the market.

[0026] (2) Slab laying The eight layers of veneer are laid in sequence, from bottom to top: whole sheet of veneer, non-whole sheet of veneer, radial bamboo strips, directional wood strips, radial bamboo strips, non-whole sheet of veneer, whole sheet of tangential bamboo mat, and wear-resistant layer.

[0027] Specific process parameters: The first layer is a whole sheet of wood veneer: the wood grain of the veneer is laid horizontally, and there is one layer of veneer. The commonly used size is 1220×2440mm, but it can also be made into a specific size as needed.

[0028] The second layer is non-sheet wood veneer: the wood grain of the veneer is laid horizontally, and there is only one layer of veneer, which is made up of multiple veneers to form a whole sheet.

[0029] The third layer is radial bamboo blinds: bamboo strips are laid longitudinally, and the number of layers depends on the requirements of the finished product materials, generally 3 to 5 layers of bamboo blinds.

[0030] The fourth layer is oriented timber strips: the timber strips are laid longitudinally, and the thickness of the laying depends on the requirements of the finished material, generally 30-60mm.

[0031] The fifth layer is a radial bamboo blind: the bamboo strips are laid longitudinally, and the number of layers depends on the requirements of the finished product material. Generally, there are 3 to 5 layers of bamboo blinds, and the number of layers must be the same as the third layer.

[0032] The sixth layer is non-sheet wood veneer: the wood grain of the veneer is laid horizontally, and there is only one layer of veneer, which is made up of multiple veneers to form a whole sheet.

[0033] The seventh layer is a whole sheet of tangential bamboo mat: the bamboo mat has one layer, the common size is 1220×2440mm, and it can also be made into a specific size as needed.

[0034] The eighth layer is the wear-resistant layer. The wear-resistant layer consists of one layer, with a common size of 1220×2440mm. It can also be made into a specific size as needed.

[0035] (3) Hot pressing The laid slabs are fed into a hot press, and different hot pressing processes are used to hot press and shape them according to the specifications of the final product. The following two types of hot presses can be used: 1) Intermittent single-layer hot press. The press has only one opening, with the upper and lower hot plates serving as rigid heat-conducting carriers. The blank is fed into the hot press by a loading machine, and then the plates close, completing the hot pressing process in one hot pressing cycle. Then the plates open, and the formed blank is removed by a unloading machine.

[0036] 2) Intermittent multi-layer hot press. The press has multiple openings, and its hot pressing principle is the same as that of the intermittent single-layer hot press.

[0037] Depending on the type of adhesive and the intended use of the finished sheet, the hot-pressing process and parameters can be adjusted accordingly. Generally, the following applies: 1) The hot pressing method is a "cold in, cold out" hot pressing process, which consists of "feeding - heating - hot pressing with heat preservation - cooling - depressurization and unloading". "Cold in, cold out" allows the slab to shrink rapidly after high-temperature processing, expelling air between the individual layers of the slab and preventing delamination and blistering in the finished slab. At the same time, it avoids sudden temperature rise on the slab surface, which could lead to the formation of a "surface pre-cured layer" before complete compaction.

[0038] 2) The hot pressing process is generally divided into three stages: pressurization, holding pressure, and unloading. The pressurization stage is to quickly compact the board and increase its density; the holding pressure stage is to transfer the heat of the press plate to the board, accelerate the curing of the adhesive to form glue nails, and at the same time, allow the bamboo and wood materials to further soften and bond at the glassy temperature; the unloading stage is to slowly release the internal stress and gas in the board to avoid delamination of the raw board.

[0039] 3) During the pressure holding stage, the unit pressure of the press is 1.5 to 8.0 MPa.

[0040] 4) The temperature of the hot press plate is generally 140~220℃.

[0041] (4) Trimming the edges in both directions The hot-pressed raw board is cut into standard-sized boards to form boards with neat edges.

[0042] The advantages of this invention are: 1. The physical and mechanical properties of the laminated oriented strand board (OSB) bamboo-wood composite material are superior to those of natural wood boards or other wood-based engineered wood products. 2. It can replace high-quality solid wood materials. Furthermore, to conserve superior timber resources, small-diameter logs or wood processing scraps such as veneer can be used to prepare OSB strips, thereby improving timber utilization and saving forest resources. Attached Figure Description

[0043] Figure 1 : This is a schematic diagram of a laminated oriented wood strip load-bearing bamboo-wood composite material structure according to the present invention. Figure 2 : This is a process flow diagram of a laminated oriented oriented wood strip load-bearing bamboo-wood composite material according to the present invention. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that various modifications can be made to the embodiments disclosed herein; therefore, the embodiments disclosed in the specification should not be considered as limitations on the present invention, but merely as examples to make the features of the present invention readily apparent.

[0045] like Figure 1 As shown, the structure of the laminated oriented oriented wood strip load-bearing bamboo-wood composite material of the present invention is as follows: 1 is a wear-resistant layer, 2 is a whole sheet of tangential bamboo mat, 3 is a non-whole sheet of veneer, 4 is a radial bamboo curtain, 5 is oriented wood strip, 6 is a radial bamboo curtain, 7 is a non-whole sheet of veneer, and 8 is a whole sheet of veneer.

[0046] Figure 2 This is a flowchart illustrating the manufacturing process of laminated oriented strand wood load-bearing bamboo-wood composite materials. Example

[0047] This example reflects the actual results of laboratory tests.

[0048] (1) Raw materials Abrasion-resistant layer: High abrasion-resistant polyurea paper, purchased commercially.

[0049] Whole bamboo mat with straight cross: purchased from the market.

[0050] Non-whole sheet veneer: rotary cut from eucalyptus logs, 2.5mm thick.

[0051] Radial bamboo blind: purchased from the market.

[0052] Oriented wood strips: made from 2.5mm eucalyptus veneer.

[0053] Whole sheet of veneer: rotary cut from eucalyptus logs, 2.5mm thick.

[0054] (2) Adhesive Type of adhesive: Phenolic resin (PF) adhesive Solid content: 40% Viscosity: 14s (Ford Cup 4, 20°C) (3) Technical means Manually apply adhesive and test press for hot pressing molding.

[0055] (4) Hot pressing parameters Hot pressing temperature: 140~180℃ Hot pressing pressure: 2.0~2.8Mpa Hot pressing time: 50~90s / mm thickness (5) Sample size 450×450×28mm (6) Mechanical properties Static bending strength: 42.0 MPa (parallel), 23.5 MPa (perpendicular) Elastic modulus: 4900 MPa (parallel), 2240 MPa (vertical) Internal bond strength: 0.88 MPa Density: 1050 kg / m³ The material manufactured using the method for producing laminated oriented strand board (OSB) load-bearing bamboo-wood composite material disclosed in this invention was tested according to the national standard "Test Methods for Physical and Chemical Properties of Wood-based Panels and Decorative Wood-based Panels (GB / T 17657-2022)". Its mechanical properties are significantly better than those specified in the national standards for particleboard (GB / T 4897-2015), medium density fiberboard (GB / T 11718-2021), oriented strand board (GB / T 41715-2022), and common plywood (GB / T 9846-2015), as shown in the table below.

[0056] Comparison Table of Mechanical Performance Indicators of the Prototype of this Invention with Relevant National Standards for Wood-based Panels

[0057] Advantages of this invention: It uses bamboo and wood as the main raw materials, especially wood processing scraps, and the physical and mechanical properties of the product are superior to natural wood boards or other wood-based artificial board materials. It can be used in load-bearing places and saves forest resources.

[0058] The embodiments described above are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a laminated oriented strand wood (OST) bamboo-wood composite material, characterized in that: It includes the following processes: (1) Material preparation process The material preparation process includes: preparation, impregnation, and drying of whole tangential bamboo mats; preparation, impregnation, and drying of radial bamboo curtains; preparation, drying, and gluing of oriented wood strips; preparation, drying, and gluing of wood veneer; and selection of wear-resistant layer materials. (2) Slab laying The eight layers of veneer are laid from bottom to top: whole sheet of veneer, non-whole sheet of veneer, radial bamboo strips, directional wood strips, radial bamboo strips, non-whole sheet of veneer, whole sheet of tangential bamboo mat, and wear-resistant layer. (3) Hot pressing The slab is fed into a hot press for hot pressing to produce laminated oriented load-bearing bamboo and wood composite material slab; The thickness of the laminated oriented oriented wood strip load-bearing bamboo-wood composite board is 15~40mm; (4) Trimming the edges in both directions The hot-pressed laminated oriented wood strip load-bearing bamboo and wood composite material blank is trimmed to form a standardized laminated oriented wood strip load-bearing bamboo and wood composite material.

2. The manufacturing method of the laminated oriented strand wood load-bearing bamboo-wood composite material according to claim 1, characterized in that: The entire tangential bamboo mat and radial bamboo curtain are impregnated with adhesive. The ratio of the solid amount of adhesive to the weight of the completely dry bamboo mat / completely dry bamboo curtain is (3-12):

100. The moisture content of the bamboo mat and bamboo curtain after drying is 2%-8%. The oriented wood strips are treated with adhesive, and the weight ratio of adhesive solids to oven-dry wood shavings is (3-12):100; after adhesive treatment, the moisture content of the oriented wood strips is 2%-12%. The wood veneer is treated with glue, and the glue application ratio is: glue solids: oven-dry veneer weight (by weight) = (3~12):100; the moisture content of the veneer after gluing is 2%~12%.

3. The method for manufacturing the laminated oriented strand wood load-bearing bamboo-wood composite material according to claim 1, characterized in that: The veneer installation consists of eight layers from bottom to top: the first layer is a single sheet of veneer laid horizontally; the second layer is a non-single sheet of veneer laid horizontally; the third layer is radial bamboo strips laid vertically, the number of strips depending on the finished product requirements, generally 3-5 layers; the fourth layer is oriented strands of wood laid vertically, the thickness depending on the finished product requirements, generally 30-60mm; the fifth layer is radial bamboo strips laid vertically, the number of strips depending on the finished product requirements, generally 3-5 layers, and the number of layers must be the same as the third layer; the sixth layer is a non-single sheet of veneer laid horizontally; the seventh layer is a single sheet of tangential bamboo mat; and the eighth layer is a wear-resistant layer, with one layer of wear-resistant material.

4. The method for manufacturing the laminated oriented strand wood load-bearing bamboo-wood composite material according to claim 1, characterized in that: The hot press is an intermittent single-layer hot press or an intermittent multi-layer hot press; The hot pressing method is a "cold in - cold out" hot pressing molding process, specifically the steps of "feeding - heating - holding hot pressing - cooling - unloading"; The hot pressing process is divided into three stages: pressure increase, pressure holding, and unloading. During the pressure holding stage, the unit pressure of the hot press is 1.5 to 8.0 MPa, and the temperature of the hot press plate is 140 to 220℃.

5. The method for manufacturing the laminated oriented strand wood load-bearing bamboo-wood composite material according to claim 1, characterized in that: The method for preparing the oriented wood strips is as follows: Logs are shaped into oriented strands using a veneer slicer or a shearing machine. The oriented strands are then dried and mixed with or sprayed with adhesive using a glue mixer. The specifications for oriented wood strips are 150~200mm in length, 15~20mm in width, and ≤4.0mm in thickness.

6. The method for manufacturing the laminated oriented strand wood load-bearing bamboo-wood composite material according to claim 1, characterized in that: The method for preparing the wood veneer is as follows: Logs are veneered using a veneer veneer veneer cutter. Large-format veneers are spliced ​​together to form whole sheets of chemically treated veneer, while small-format veneers are spliced ​​together to form non-whole sheets of chemically treated veneer. The veneers are first dried and then glued using a glue applicator. The veneer thickness is ≤4.0mm. The commonly used size for whole sheets of chemically treated veneer is 1220×2440mm, but specific sizes can also be made as needed.

7. The method for manufacturing the laminated oriented strand wood load-bearing bamboo-wood composite material according to claim 1, characterized in that: The adhesives used for impregnation, application, and coating are: isocyanate resin (MDI), phenolic resin (PF), urea-formaldehyde resin (UF), or other adhesives used in the wood-based panel industry.

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