Manufacturing method of composite wallboard for bamboo engineering

Abstract

The invention discloses a manufacturing method of a composite wallboard for bamboo engineering, which comprises the following steps of: S1, coating any surface of a panel layer with an adhesive by taking a recombined bamboo or bamboo laminated wood board as the panel layer; s2, connecting the core layer frame between the two panel layers to form a plate blank; a filling hole cavity is formed in the core layer frame; s3, the plate blank is subjected to hot pressing or cold pressing forming under the pressure condition of 0.5-10 MPa; and S4, the filling hole cavities of the core layer frame are filled with resin, and after the resin is cured, the composite wallboard for the bamboo engineering is obtained. Compared with the technical scheme that the resin is injected firstly and then the pressing forming is performed, when an excellent heat preservation and heat insulation effect is formed, the bonding effect during resin curing further strengthens the connection firmness degree and integrity of the panel layer and the core layer; the adhesive area can be greatly increased, one-time forming is achieved during strengthening, and the phenomenon that the surface core layer is prone to disengagement and layering during later use is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of bamboo composite materials, and in particular to a method for manufacturing a bamboo composite wallboard for engineering use. Background Art

[0002] Traditional steel-concrete structure buildings have problems such as non-renewable resources, high energy consumption, and high carbon emissions, which do not conform to the concept and trend of green safety, energy conservation, environmental protection, and sustainable development. Therefore, developing new building materials that are green, low-carbon, and sustainable, and vigorously developing green ecological buildings are of great practical significance for practicing the concept of green and sustainable development.

[0003] Wood and bamboo are the only green and renewable ecological materials among the four major building materials. One ton of wood and bamboo can not only store about 1.8 tons of CO 2 , and the CO generated by producing unit mass of wood and bamboo building materials 2 The emission equivalent is only about 1 / 40 of cement, 1 / 100 of plastic, and 1 / 200 of steel. Due to the scarcity of wood resources in my country, most of the use of wood depends on imports, and the promotion and application of wooden structure buildings in my country are seriously restricted. my country has the most abundant bamboo resources and is known as the "Bamboo Kingdom". Bamboo has significant advantages such as fast growth, short maturity period, and sustainable logging and utilization. It is a typical green biomass natural renewable material. Compared with wood, steel, and cement, bamboo has higher specific strength and is known as "plant steel". It has broad application prospects in the field of engineering and construction. Compared with traditional engineering and construction materials such as steel and cement, the application of bamboo in the field of construction engineering has problems such as high manufacturing cost and high cost, and difficulty in manufacturing large-scale components. How to significantly reduce the manufacturing cost of large-scale bamboo components while ensuring mechanical strength is an important issue to expand the application field of bamboo, increase the added value of bamboo products, and develop green building materials and low-carbon buildings.

[0004] The sandwich panel structure is a structure with a high stiffness-to-weight ratio. Due to its potential of being lightweight and high-strength, it has now been widely used in fields such as aerospace, shipbuilding, and construction engineering. The existing sandwich panel structure consists of an upper layer, a lower layer, and a core layer located between the upper layer and the lower layer. In order to better improve the sound insulation performance or heat insulation performance of the sandwich panel structure, the following several common technical solutions exist for the existing core body: 1. The core layer is prepared from a whole piece of sound insulation or heat insulation material (foaming resin); 2. The core layer adopts a honeycomb partition board with a surface impregnated or coated with a sound insulation or heat insulation material (foaming resin); 3. The main body of the core layer adopts a honeycomb partition board, and a sound insulation or heat insulation material (foaming resin) is filled in the honeycomb partition board cavity. No matter which core body is adopted, in the existing technology when preparing the sandwich panel structure, the common preparation method is: bonding the core layer, the upper layer, and the lower layer with an adhesive, and then applying pressure for curing. For the first technical solution, due to the lack of a support member with higher strength in the core layer, there are technical problems such as insufficient strength of the sandwich panel structure and difficulty in fixing the thickness due to easy compression of the core layer during pressing. For the second technical solution, it is necessary to impregnate or coat the honeycomb partition board with foaming resin, and then carry out the next step after the foaming resin is initially cured. The construction period is relatively long, and it is difficult to achieve assembly line operation and low production efficiency in industrial production. The core layer and the surface layer are only bonded through the wall thickness of the core layer, and the surface layer and the core layer are prone to detachment and delamination during later use. For the third technical solution, after filling the foaming resin in the honeycomb partition board to form the core layer, it is then bonded to the surface layer, and pressure is applied to cure and form the whole after bonding. In such a process technical solution, when the foaming resin cures, there is no upper and lower surface layers for limiting, so it is easy to be uneven, and there are gaps in some areas during later bonding with the surface layer. Moreover, it can only be bonded through a small amount of adhesive coated on the surface of the panel, and cannot utilize the large number of self-integrated bonding surfaces formed during the filling and curing of the core layer foaming resin for bonding. Therefore, it cannot maximize the bonding effect of further strengthening the connection firmness and integrity between the upper layer, the lower layer, and the core layer, and is only used for enhancing the heat insulation performance, and there are still technical problems existing in the second technical solution. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a manufacturing method of a bamboo-based engineering composite wallboard that can effectively avoid detachment and delamination between the surface layer and the core layer during use and has high production efficiency.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A manufacturing method of a bamboo-based engineering composite wallboard includes the following steps:

[0008] S1. Using recombined bamboo or bamboo laminated lumber board as the panel layer, and coating an adhesive on any surface of the panel layer;

[0009] S2. Connect the core layer framework between two panel layers to form a slab blank; a filling hole cavity is provided in the core layer framework;

[0010] S3. Hot press or cold press the slab blank under a pressure condition of 0.5 - 10 MPa to form a shape;

[0011] S4. Fill the filling hole cavity of the core layer framework with resin, and after the resin is cured, a composite wallboard for bamboo engineering is obtained.

[0012] As a further improvement of the above technical solution:

[0013] In the step S2, the core layer framework includes a frame and reinforcing members located inside the frame. The filling hole cavity is located in the area surrounded by the frame and the reinforcing members. A pouring port is provided on the frame, and the pouring port is used to fill the filling hole cavity with resin.

[0014] In the step S2, the pouring port is a through hole with a diameter of 5 mm - 12 mm.

[0015] In the step S2, the reinforcing members are arranged in an array by a plurality of reinforcing units, and the reinforcing unit is a truss.

[0016] In the step S2, the reinforcing member is a corrugated plate.

[0017] In the step S2, the reinforcing member is composed of a porous periodic structure. The filling hole cavity further includes inner holes in the porous periodic structure. First flow holes are provided on the side wall of the porous periodic structure, and the first flow holes are communicated with the pouring port to facilitate the flow of resin in the pores of the porous periodic structure.

[0018] In the step S2, the cross-sectional shape of the inner hole of the porous periodic structure is polygonal or circular. When the reinforcing member is composed of a porous periodic structure, the reinforcing member is a grid-like structure or a honeycomb-like structure.

[0019] In the step S2, the following steps are included:

[0020] A1. Connect the frame to the glue-coated surface of one panel layer;

[0021] A2. Connect the reinforcing members to the panel layer within the area surrounded by the frame, and then place the glue-coated surface of the other panel layer downward on the core layer framework to obtain a slab blank.

[0022] In the step A1, the frame is connected to the panel layer by using connecting pieces; in the step A2, the reinforcing members are connected to the panel layer by using connecting pieces.

[0023] The resin is one or several of sound insulation materials, heat insulation materials, and flame retardant materials.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] In the manufacturing method of the bamboo-based composite wallboard for engineering of the present invention, resin is injected for strengthening after pressing and forming. When the resin forms an excellent heat insulation effect, compared with the technical solution of injecting resin first and then pressing and forming, on the one hand, the bonding effect during the curing of the resin in the present invention further strengthens the connection firmness and integrity between the panel layer and the core layer, and can greatly increase the adhesive area to be formed in one step during strengthening, avoiding the easy detachment and delamination of the surface and core layers during later use. On the other hand, there is no need to wait for the resin to cure before proceeding to the next step before pressing and forming, which enables assembly line operation, saves time, and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an external view of the bamboo-based engineering composite wallboard of the present invention.

[0027] Figure 2 It is a disassembled structure diagram of the grid-shaped core layer bamboo-based engineering composite wallboard in Embodiment 1 of the present invention.

[0028] Figure 3 It is a schematic diagram of the position structure of the first flow hole of the present invention. Figure 3 (a) is V-shaped, Figure 3 (b) is circular, Figure 3 (c) is rectangular.

[0029] Figure 4 It is a process flow chart of the manufacturing method of the present invention.

[0030] Figure 5 It is a disassembled structure diagram of the honeycomb-shaped core layer bamboo-based engineering composite wallboard in Embodiment 2 of the present invention.

[0031] Figure 6 It is a disassembled structure diagram of the truss-shaped core layer bamboo-based engineering composite wallboard in Embodiment 3 of the present invention.

[0032] Figure 7 It is a disassembled structure diagram of the corrugated core layer bamboo-based engineering composite wallboard in Embodiment 4 of the present invention.

[0033] Each label in the figure represents:

[0034] 1. First panel layer; 2. Second panel layer; 3. Core board layer; 31. Frame; 32. Reinforcing member; 321. First flow hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following will further elaborate on the present invention in detail. Unless otherwise specified, the instruments or materials used in the present invention are commercially available.

[0036] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0037] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0038] In the present invention, unless otherwise clearly specified and defined, terms such as "connected", "joined", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] A manufacturing method of a composite wallboard for bamboo engineering of the present invention includes the following steps:

[0040] S1. Using reconstituted bamboo or bamboo laminated lumber board as the panel layer, and coating an adhesive on any surface of the panel layer;

[0041] S2. Connecting the core layer frame between two panel layers to form a board blank; the core layer frame is provided with filling cavities;

[0042] S3. Hot pressing or cold pressing the board blank under a pressure condition of 0.5 - 10 MPa to form a shape;

[0043] S4. Filling resin into the filling cavities of the core layer frame, and after the resin is cured, obtaining the composite wallboard for bamboo engineering.

[0044] In the manufacturing method of the present invention, after compression molding, resin is injected for strengthening to form an excellent heat insulation effect. Compared with the technical solution of injecting resin first and then performing compression molding, on the one hand, the bonding effect during the curing of the resin in the present invention further strengthens the connection firmness and integrity between the panel layer and the core layer, and can greatly increase the adhesive area to be formed in one step during strengthening, avoiding the easy detachment and delamination of the surface and core layers during later use. On the other hand, there is no need to wait for the resin to cure before proceeding to the next step before compression molding, which enables assembly line operation, saves time, and improves production efficiency.

[0045] In step S1, the amount of glue applied on one side of the panel layer is controlled within 60 - 210 g / m 2 .

[0046] In step S1, the adhesive is an environmentally friendly weather-resistant glue type, which can be isocyanate, polyurethane, resorcinol, epoxy resin, phenolic resin, modified urea-formaldehyde resin, etc., to ensure that during the use of the finished product, the release of volatile organic compounds meets the requirements for indoor building materials and requirements such as strength and weather resistance.

[0047] In step S1, the adhesive coating is achieved by roll coating or spraying methods, and efforts are made to ensure uniform coating and proper coating of the glue layer on the panel.

[0048] The thickness of the bamboo-based engineering composite wallboard prepared by the present invention is between 50 mm and 300 mm, the length is greater than 2 m, the overall density of the composite wallboard is less than 650 kg / m 3 , the compressive strength ≥ 3.5 Mpa, there are no cracks on the board surface after 5 impact resistance tests, and the heat transfer coefficient is less than 0.450 W / m 2 ·K, and the air-borne sound insulation amount is greater than 45 dB.

[0049] As Figure 1 shown, the bamboo-based engineering composite wallboard of the present invention has a sandwich structure, including a first panel layer 1, a second panel layer 2, and a core board layer 3 connected between the first panel layer 1 and the second panel layer 2.

[0050] As Figure 2As shown, the core board layer 3 includes a core layer framework and resin (not shown in the figure). The core layer framework includes a border 31 and a reinforcing member 32 located inside the border 31. A filling hole cavity is formed in the area surrounded by the border 31 and the reinforcing member 32. A pouring port (not shown in the figure) is provided on the border 31. The pouring port is used to fill resin into the filling hole cavity, and the resin fills and fills the filling hole cavity. In the present invention, the core board layer 3 is strengthened by the reinforcing member 32. The resin is a functional material, which is in a liquid state before curing and is convenient for pouring, and cures and forms at room temperature. While the reinforcing member 32 bears the load strength, it is beneficial to the functional manufacturing of the overall structure such as light weight, heat insulation and noise reduction. The functional material enhances the performance of noise reduction, fire insulation and impact resistance, etc., and can meet the design and construction requirements of modern prefabricated bamboo structure components, and can be widely applied to modern bamboo and wood structure construction projects, replacing concrete walls and other fields.

[0051] The border 31 of the present invention is a bamboo border strip. The thickness of the border strip is equal to the thickness of the core board layer 3. The length of the border strip along the length direction of the wall panel is equal to or less than the length of the wall panel, and the length of the border strip along the width direction of the wall panel is equal to or less than the width of the wall panel.

[0052] The materials of the first panel layer 1 and the second panel layer 2 of the present invention are bamboo laminated lumber or bamboo recombined lumber, and the thickness is between 5 mm and 100 mm.

[0053] When the first panel layer 1 and the second panel layer 2 of the present invention are bamboo laminated lumber, the length direction of the surface bamboo fibers is consistent with the length direction of the wall panel. The length direction of the bamboo fibers close to the core board layer 3 can be consistent with the length direction of the wall panel or perpendicular. In the length direction of the bamboo laminated lumber, the bamboo strips are longitudinally connected by finger jointing, hook jointing and other methods, and the tensile strength at the joint is not less than 80% of the tensile strength of the bamboo itself along the grain; in the width direction of the bamboo laminated lumber, the bamboo strips are assembled by flat pressing or side pressing gluing methods, and the gluing strength is not less than 80% of the tensile strength of the bamboo itself across the grain.

[0054] When the first panel layer 1 and the second panel layer 2 of the present invention are bamboo recombined lumber, the length direction of the surface bamboo fibers is consistent with the length direction of the wall panel. The length direction of the bamboo fibers close to the core layer can be consistent with the length direction of the wall panel or perpendicular.

[0055] In some embodiments of the present invention, the bamboo laminated lumber is formed by lengthening the specified bamboo slice units in the length direction and then gluing and pressing them into a board with a set width and thickness in a side-by-side, flat-by-flat or mixed-by-flat manner. In some embodiments of the present invention, the bamboo recombined lumber is a board formed by assembling the glued and dried bamboo bundle units along the grain direction and then forming them by a hot pressing process.

[0056] The pouring port connects the filling hole cavity with the outside. In this embodiment, the pouring port is a through hole with a diameter of 5 mm - 12 mm.

[0057] The material of the reinforcing member 32 of the present invention is one or more of paper, bamboo, and aluminum materials.

[0058] In some embodiments of the present invention, the reinforcing member 32 is composed of a porous periodic structure. The filling cavity further includes inner holes within the porous periodic structure. First flow holes 321 are formed in the side walls of the porous periodic structure, and the first flow holes 321 are communicated with the gating system to facilitate the flow of resin in the inner holes of the porous periodic structure. After the resin is cured, the inner holes are filled with resin.

[0059] The cross-sectional shape of the inner holes of the porous periodic structure is polygonal or circular.

[0060] In some embodiments of the present invention, the reinforcing member 32 is formed by arranging a plurality of reinforcing units in an array, and the reinforcing units are trusses.

[0061] In some embodiments of the present invention, the reinforcing member 32 is a corrugated board.

[0062] The core layer frame is bonded to the first panel layer 1 or the second panel layer 2. In some embodiments, in addition to bonding the upper and lower surfaces of the core layer frame to the first panel layer 1 and the second panel layer 2 respectively, additional connecting members are further used for connection and fixation. The connecting members are soft nails, staples, screws, etc.

[0063] The resin is bonded to the first panel layer 1, the second panel layer 2, the frame 31, and the reinforcing member 32 respectively.

[0064] As Figure 3 shown, the first flow holes 321 are located in the upper part or the top of the reinforcing member 32. Preferably, the first flow holes 321 are located at the top of the reinforcing member 32. In this way, it is convenient for the resin to quickly fill the cavity by the action of gravity.

[0065] When the thickness of the bamboo engineering composite wallboard of the present invention is greater than 200 mm, a porous periodic structure arranged in a double-layer or multi-layer staggered plug-in manner is used as the reinforcing member 32, which is beneficial to improving the strength and stiffness of the bamboo engineering composite wallboard and avoiding excessive deformation under ultimate load or impact conditions.

[0066] When the thicknesses of the first panel layer 1 and the second panel layer 2 of the slab are greater than 50 mm, room temperature curing adhesives are used for adhesive forming under cold pressing conditions to avoid the situation that heat cannot be transferred to the adhesive layer in a short time due to the large thickness of the board, thus affecting the gluing effect.

[0067] Embodiment 1

[0068] For the composite wallboard for bamboo engineering in this embodiment, the reinforcing member 32 is a grid core, which is formed by the criss-crossing of a plurality of horizontally arranged recombined bamboo strips and a plurality of vertically arranged recombined bamboo strips. The recombined bamboo strips are provided with first through holes 321, so that the inner holes of the grid core communicate with each other, facilitating the uniform filling of resin in the inner holes of the grid core.

[0069] In this embodiment, the cross-sectional shape of the inner hole of the porous periodic structure is quadrilateral, which is the grid core. In other embodiments, it can be triangular, pentagonal, hexagonal, circular, etc.

[0070] In this embodiment, the cross-section of the first through hole 321 is V-shaped (as shown in Figure 3 (a)), and in other embodiments, it can be circular, square, rectangular or other shapes (as shown in Figure 3 (b), Figure 3 (c)).

[0071] In this embodiment, the resin is foamed polyurethane. Before foaming and curing, the resin is in a liquid state and can flow rapidly in the filling cavities until all the cavities are filled.

[0072] As shown in Figure 4 , a manufacturing method of the composite wallboard for bamboo engineering in this embodiment includes the following steps:

[0073] (1) Material processing:

[0074] Preparation of the panel layer: Using bamboo bundle units with a length of 3 m as raw materials, through heat treatment, dipping in glue, drying, arranging in the same direction and hot pressing, machining and other processes, recombined bamboo boards with a length of 3 m, a width of 1.2 m, a thickness of 18 mm and 12 mm are processed, which are used as the first panel layer 1 and the second panel layer 2 respectively. The first panel layer 1 is the outer panel (the side away from the wall), and the second panel layer 2 is the inner panel (the side facing the wall);

[0075] Preparation of the core layer framework: Using recombined bamboo boards with a cross-sectional size of 100 mm × 20 mm as grid bars, along the length direction of the wallboard, a V-shaped groove with a bottom side of 10 mm and a height of 5 mm (as shown in Figure 3 (a)) is processed on the upper surface of each grid unit of the grid bar as the first through hole 321 to ensure that each grid unit has a notch; Using recombined bamboo boards with a width of 100 mm and a thickness of 20 mm as frame bars (frame 31), circular holes with a diameter of 5 mm are drilled at the positions of the frame bars matching the notches of the grid units as pouring ports for injecting foamed resin in the subsequent core layer strengthening step.

[0076] In this embodiment, the reserved notch of the grid bar is a V-shaped groove opening. In other embodiments, it can be a rectangular, circular or other shaped notch (as shown in Figure 3 (b), (c)).

[0077] (2) Adhesive Coating: Epoxy resin adhesive is evenly coated on the lower surface of the first panel layer 1 and the upper surface of the second panel layer 2 respectively. The single-sided adhesive application amount is controlled within the range of 100 - 120 g / m 2 (in this embodiment, preferably 110 g / m 2 ).

[0078] (3) Composite Lamination: The frame bars are placed around the recombinant bamboo board coated with adhesive on one side. Then, the frame bars and the grid bars are sequentially fixed on the panel coated with adhesive using screws. The frame bars are sequentially connected to form the frame 31, and the grid bars are arranged vertically and horizontally to form the reinforcement 32. At the vertically and horizontally intersecting positions of the grid bars, screws or angle codes can be used for fastening and strengthening. Finally, the coated surface of the other panel is placed downward on the frame structure formed by the grid and the frame bars to obtain the board blank. In this embodiment, the grid bars in the length direction are arranged in a staggered manner to further improve the uniform load-bearing and impact resistance stability of the composite wallboard for bamboo engineering.

[0079] (4) Press Forming: The board blank after composite lamination is placed along the height direction and placed on a cold press. After being kept under a pressure of 4 MPa for 5 h, it is taken out to obtain the initial product of the composite wallboard for bamboo engineering. In some embodiments of the present invention, multiple board blanks can be stacked along the height direction and pressed together to form the shape at one time, and multiple initial products can be obtained in one pressing, with higher production efficiency and lower cost.

[0080] (5) Core Layer Strengthening: Foamed polyurethane is injected through the casting port reserved on the frame 31 of the composite wallboard for bamboo engineering and flows through the first through-hole 321 to fill all the gaps between the panel and the core layer, forming an integral sandwich structure in the thickness direction. This can effectively reduce the hardware connection operation while ensuring sufficient structural strength. Moreover, when an excellent heat insulation effect is formed after strengthening, the bonding effect during the curing of the foamed resin can further strengthen the connection firmness and integrity between the inner, the first panel layer 1 and the core layer. Compared with the panel and the grid structure where only the grid wall thickness part is in contact and bonded, the adhesive area can be greatly increased and formed in one step during strengthening, avoiding the easy detachment and delamination of the surface and core layers during later use.

[0081] (6) Post-Processing: Each surface of the initial product of the composite wallboard for bamboo engineering is processed by machining such as sanding and polishing to obtain the composite wallboard for bamboo engineering.

[0082] The length of the composite wallboard for bamboo engineering produced in this embodiment is 3 m, the width is 1.2 m, the thickness is 130 mm, the actual density is 0.450 g / cm 3 , and the heat transfer coefficient is 0.216 W / m 2 ·K, and the weighted sound insulation of the wallboard for airborne sound is 55 dB.

[0083] Example 2

[0084] As Figure 5 shown, the composite wallboard for bamboo engineering in this embodiment is substantially the same as that in Embodiment 1, except that: in this embodiment, the reinforcing member 32 is of a honeycomb structure. The honeycomb structure is also provided with first through holes 321. The honeycomb core can be made of paper, aluminum, bamboo and fiber-reinforced base materials, and has sufficient strength, stiffness and impact resistance.

[0085] The preparation method of the composite wallboard for bamboo engineering in this embodiment is substantially the same as that in Embodiment 1, except that: in the material processing step of step (1), the honeycomb structure is used to replace the grid base material.

[0086] Example 3

[0087] As Figure 6 shown, the composite wallboard for bamboo engineering in this embodiment is substantially the same as that in Embodiment 1, except that: in this embodiment, the reinforcing member 32 is of a truss structure. The truss is composed of a plurality of truss units, and each truss unit is formed by a plurality of rods into an umbrella bone-like structure, and the first through holes 321 do not need to be provided.

[0088] The preparation method of the composite wallboard for bamboo engineering in this embodiment is substantially the same as that in Embodiment 1, except that: in the material processing step of step (1), the truss is used to replace the grid base material.

[0089] Example 4

[0090] As Figure 7 shown, the composite wallboard for bamboo engineering in this embodiment is substantially the same as that in Embodiment 1, except that: in this embodiment, the reinforcing member 32 is of a corrugated structure, which can be formed by stamping a whole plate or connected by a plurality of plates, and the first through holes 321 need to be provided at the top of the corrugated structure.

[0091] The preparation method of the composite wallboard for bamboo engineering in this embodiment is substantially the same as that in Embodiment 1, except that: in the material processing step of step (1), the corrugated structure is used to replace the grid base material.

[0092] Example 5

[0093] The composite wallboard for bamboo engineering in this embodiment is substantially the same as that in Embodiment 1, except that: the reinforcing member 32 is formed by a plurality of horizontally arranged bamboo laminated bamboo slats and a plurality of vertically arranged bamboo laminated bamboo slats intersecting with each other. The bamboo laminated bamboo slats are provided with first through holes 321 to make the inner holes of the grid core communicate with each other, so as to facilitate the uniform filling of resin in the inner holes of the grid core.

[0094] A manufacturing method of the composite wallboard for bamboo engineering in this embodiment includes the following steps:

[0095] (1) Material processing:

[0096] Preparation of the panel layer: Using bamboo strips with specifications of 21 mm in width and 6.5 mm in thickness as raw materials, the bamboo strips are processed by finger-jointing and side-pressing hot pressing to form a side-pressed bamboo laminated lumber with a length of 3 m, a width of 1.2 m, and a thickness of 20 mm, which are used as the first panel layer 1 and the second panel layer 2 respectively. The first panel layer 1 is the outer panel (the side away from the wall), and the second panel layer 2 is the inner panel (the side facing the wall);

[0097] Preparation of the core layer frame: Using bamboo laminated lumber with a cross-sectional size of 100 mm × 20 mm as the grid bars, along the length direction of the wall panel, a V-shaped groove with a bottom side of 10 mm and a height of 5 mm is processed on the upper surface of each grid cell of the grid bars using a V-shaped cutter (as shown in Figure 3 (a)) as the first flow hole 321 to ensure that each grid cell has a notch; using bamboo laminated lumber with a width of 100 mm and a thickness of 20 mm as the border bars (border 31), and circular holes with a diameter of 5 mm are drilled at the positions where the border bars match the notches of the grid cells as the pouring ports for injecting foaming resin in the subsequent core layer strengthening step.

[0098] In this embodiment, the reserved notch of the grid bars is a V-shaped groove opening, and in other embodiments, it can be other shapes such as rectangular or circular notches (as shown in Figure 3 (b), (c)).

[0099] (2) Adhesive coating: Epoxy resin adhesive is evenly coated on the lower surface of the first panel layer 1 and the upper surface of the second panel layer 2 respectively, and the single-sided adhesive application amount is controlled within the range of 100 - 120 g / m 2 (in this embodiment, preferably 110 g / m 2 ).

[0100] (3) Composite blanking: Place the border bars around the bamboo laminated lumber with adhesive coated on one side, and then use nails to fix the border bars and grid bars to the panel with adhesive in sequence. The border bars are connected in sequence to form the border 31, and the grid bars are arranged vertically and horizontally to form the strengthening member 32. At the vertically and horizontally intersecting positions of the grid bars, nails or corner codes can be used for fastening and strengthening. Finally, place the other panel with the adhesive-coated surface facing down on the frame structure built by the grid and border bars to obtain the board blank. In this embodiment, the grid bars in the length direction are arranged in a staggered manner to further improve the uniform load-bearing and impact resistance stability of the composite wall panel for bamboo engineering.

[0101] (4) Press forming: Place the board blank after composite blanking along the height direction, place it on a cold press, and keep it under a pressure of 4 MPa for 5 h and then take it out to obtain the initial product of the composite wall panel for bamboo engineering.

[0102] (5) Core layer reinforcement: Pour foamed polyurethane into the casting openings reserved in the frame 31 of the bamboo-based engineered composite wall panel. It flows through the first flow holes 321 to fill all the gaps between the panel and the core layer, forming an integral sandwich structure in the thickness direction. This can effectively reduce the hardware connection operations and ensure sufficient structural strength. When an excellent thermal insulation effect is formed after reinforcement, the bonding effect during the curing of the foamed resin can further strengthen the connection firmness and integrity between the inner and the first panel layers 1 and the core layer. Compared with the panel and grille structure where only the wall thickness part of the grille is in contact bonding, the adhesive area can be significantly increased and formed in one step during reinforcement, avoiding the easy detachment and delamination of the surface and core layers during later use.

[0103] (6) Post-processing: Machine-process the surfaces of the initial products of the bamboo-based engineered composite wall panels, such as sanding and polishing, to obtain the bamboo-based engineered composite wall panels.

[0104] The length of the bamboo-based engineered composite wall panel produced in this embodiment is 3 m, the width is 1.2 m, the thickness is 140 mm, and the actual density is 0.320 g / cm 3 , and the heat transfer coefficient is 0.208 W / m 2 ·K. The weighted sound insulation of the wall panel for airborne sound is 58 dB.

[0105] Comparative Example 1

[0106] A manufacturing method of a bamboo-based engineered composite wall panel in this comparative example includes the following steps:

[0107] (1) Material processing:

[0108] Using bamboo bundle units with a length of 3 m as raw materials, through heat treatment, dipping in glue, drying, arranging in parallel grains and hot pressing and other processes, processed into a reconstituted bamboo with a length of 3 m, a width of 1.2 m, a thickness of 18 mm and 12 mm as the first panel layer 1 and the second panel layer 2;

[0109] Adopt reconstituted bamboo with a cross-sectional size of 100 mm × 20 mm as the core layer grille base material; use reconstituted bamboo with a width of 100 mm and a thickness of 20 mm as the frame strip.

[0110] (2) Adhesive coating: Uniformly coat epoxy resin adhesive on the lower surface of the first panel layer 1 and the upper surface of the second panel layer 2. The single-sided glue application amount of the adhesive is controlled within the range of 100 - 120 g / m 2 (in this comparative example, it is 110 g / m 2 ).

[0111] (3) Fixing of the border strips and grid strips: Place the border strips around the recombinant bamboo boards coated with adhesive on one side, and then use screws to fix the border strips and grid strips to the bottom plate in sequence. At the crisscross positions of the grid strips, screws or corner brackets are used for fastening and strengthening.

[0112] (4) Core layer strengthening: Fill solid heat-insulating materials between the grids and between the grids and the border strips. During filling, try to ensure full filling to avoid poor local heat-insulating performance caused by insufficient filling or shaking of the filling material during subsequent use.

[0113] (4) Composite blank assembly: Then place the coated surface of another panel facing down on the frame structure formed by the grids and border strips to obtain a board blank.

[0114] (5) Press forming: Stack the board blanks after composite blank assembly layer by layer along the height direction, place them on a cold press, and keep them under a pressure of 4 MPa for 5 h and then take them out to obtain the initial product of the composite wallboard for bamboo engineering.

[0115] (6) Post-processing: Process the surfaces of the initial product of the composite wallboard for bamboo engineering by sanding, grinding and other machining processes to obtain the composite wallboard for bamboo engineering.

[0116] For the composite wallboard for bamboo engineering produced in this comparative example, heat-insulating materials are filled before blank assembly instead of uniformly strengthening the core layer after press forming. When filling, there is no upper and lower surface layer for limiting, which makes it easy to be uneven. When bonding with the surface layer later, gaps are likely to appear in some areas. And it can only be bonded by a small amount of adhesive coated on the surface of the panel, and cannot rely on the large number of self-integrated bonding surfaces formed during the filling and curing of the core layer foaming resin for bonding. It is easy to cause poor local heat-insulating performance due to insufficient filling or shaking of the filling material during subsequent use. Moreover, the filling of heat-insulating materials and the covering of the panel are carried out step by step as independent systems and cannot be formed at one time. When the foaming resin cures, it cannot play the bonding role of further strengthening the connection firmness and integrity of the inner layer, the first panel layer 1 and the core layer, and is only used to enhance the heat-insulating performance. During later use, the surface and core layers are likely to be separated and delaminated.

[0117] Comparative Example 2

[0118] A manufacturing method of a composite wallboard for bamboo engineering in this comparative example includes the following steps:

[0119] (1) Material processing:

[0120] Using bamboo bundle units with a length of 3 m as raw materials, through processes such as heat treatment, dipping in glue, drying, longitudinal blank assembly and hot pressing, process recombinant bamboo with a length of 3 m, a width of 1.2 m, a thickness of 18 mm and 12 mm as the first panel layer 1 and the second panel layer 2;

[0121] An aluminum honeycomb with a thickness of 10 mm and a height of 100 mm is used as the core layer material, and then it is cut into a size of 1.2 m in width and 3 m in length for standby; the recombined bamboo with a width of 100 mm and a thickness of 20 mm is used as the frame strip.

[0122] (2) Core layer filling: Immerse the aluminum honeycomb material in the polyurethane filling liquid, and then dry it in the air or heat it for drying and curing for standby.

[0123] (3) Adhesive coating: Uniformly coat the epoxy resin adhesive on the lower surface of the first panel layer 1 and the upper surface of the second panel layer 2, and the single-sided glue application amount of the adhesive is controlled within the range of 100 - 120 g / m 2 (in this comparative example, it is 110 g / m 2 ).

[0124] (3) Composite blanking: Place the frame strip on one surface of the bamboo laminated lumber panel coated with the adhesive, and then temporarily fix the frame strip on the glue-coated surface with screws. Place the filled honeycomb core material in the area surrounded by the frame strip on the panel, and then place the glue-coated surface of the other panel downward on the honeycomb core layer to obtain the blank of the composite wallboard for bamboo engineering.

[0125] (4) Press forming: Stack the blanks after composite blanking layer by layer along the height direction, place them on a cold press, keep them under a pressure of 4 MPa for 5 h and then take them out to obtain the initial product of the composite wallboard for bamboo engineering.

[0126] (6) Post-processing: Machine-process the surfaces of the initial product of the composite wallboard for bamboo engineering, such as sanding and polishing, to obtain the composite wallboard for bamboo engineering.

[0127] For the composite wallboard for bamboo engineering produced in this comparative example, the aluminum honeycomb material is filled before blanking. It is necessary to wait for the filling material to cure before proceeding to the next step, which results in a long construction time, difficulty in realizing assembly line operation, and low production efficiency. Moreover, the filling of the thermal insulation material and the covering of the panel are carried out step by step as independent systems and cannot be formed at one time. Only a small amount of adhesive applied on the surface layer of the panel can be used for bonding, and the large number of self-integrated bonding surfaces formed during the curing of the core layer foaming resin cannot be utilized for bonding. Therefore, the bonding effect that can further strengthen the connection firmness and integrity between the upper layer, the lower layer and the core layer to the greatest extent cannot be exerted, and it is only used to enhance the thermal insulation performance. During later use, the surface and core layers are prone to detachment and delamination.

[0128] Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for manufacturing a bamboo composite wallboard for engineering use, characterized in that: The following steps are involved: S1. Using reconstituted bamboo or bamboo integrated wood board as the panel layer, and coating adhesive on any surface of the panel layer; S2, connecting the core layer frame between the two face layer layers to form a slab; the core layer frame is provided with a filling cavity; S3, hot pressing or cold pressing the slab under a pressure of 0.5-10 MPa; S4, filling the filling holes of the core layer frame with resin, and obtaining the bamboo composite wallboard for engineering after the resin is cured.

2. The manufacturing method according to claim 1, characterized in that: In step S2, the core layer frame includes a frame (31) and a reinforcement member (32) located inside the frame (31); the filling cavity is located in an area enclosed by the frame (31) and the reinforcement member (32); a pouring port is provided on the frame (31); and the pouring port is used to fill resin into the filling cavity.

3. The manufacturing method according to claim 2, characterized in that: In the step S2, the pouring port is a through hole with a diameter of 5 mm to 12 mm.

4. The manufacturing method according to claim 2, characterized in that: In the step S2, the reinforcement member (32) is formed by a plurality of reinforcement units arranged in an array, and the reinforcement units are trusses.

5. The manufacturing method according to claim 2, characterized in that: In the step S2, the reinforcement member (32) is a corrugated plate.

6. The manufacturing method according to claim 2, characterized in that: In step S2, the reinforcement (32) is composed of a porous periodic structure, the filling cavity also includes an inner hole in the porous periodic structure, and a first flow hole (321) is opened on the side wall of the porous periodic structure. The first flow hole (321) is connected to the pouring port to facilitate the flow of resin in the pores in the porous periodic structure.

7. The manufacturing method according to claim 6, characterized in that: In the step S2, the cross-sectional shape of the inner pores of the porous periodic structure is polygonal or circular.

8. The manufacturing method according to claim 2, characterized in that: The step S2 includes the following steps: A1, connecting the frame (31) to the glue-coated surface of a panel layer; A2. Connect the reinforcing member (32) to the panel layer in the area enclosed by the frame (31), and then place the other panel layer with the glue-coated surface facing downward on the core layer frame to obtain a slab.

9. The manufacturing method according to claim 8, characterized in that: In the step A1, a connecting member is used to connect the frame (31) to the panel layer; in the step A2, a connecting member is used to connect the reinforcement member (32) to the panel layer.

10. The manufacturing method according to claim 1, characterized in that: The resin is one or more of sound insulation materials, heat insulation materials and flame retardant materials.

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