CN102773886A - A composite structure board of recombined bamboo and medium density fiberboard and its manufacturing method - Google Patents

Abstract

The invention relates to a composite structural plate of recombined bamboo wood and a medium-density fiberboard and a manufacturing method thereof. The composite structural plate of the recombined bamboo wood and the medium-density fiberboard provided by the invention is composed of at least one layer of recombined bamboo wood and at least one layer of medium-density fiberboard, and the thickness of the composite structural plate is 7-90 mm. The invention also provides a manufacturing method of the composite structure plate, which comprises the following steps: coating weather-resistant glue on the recombined bamboo wood and the medium-density fiberboard, wherein the weather-resistant glue is coated on the contact surface or the weather-resistant glue is coated on the surface of one side of the contact surface; assembling the recombined bamboo wood coated with the weather-resistant glue and the medium-density fiberboard to obtain a board blank; and (4) carrying out cold pressing, pressure maintaining, pressure relief and health preserving on the plate blank to obtain the recombined bamboo wood and medium-density fiberboard composite structural plate. The composite structural plate provided by the invention has good structural performance, can be automatically and continuously produced, has the advantages of simple process, high production efficiency, stable and reliable product performance, obvious cost advantage, energy conservation and environmental protection, and can meet the requirements of multiple purposes.

Description

A composite structure board of recombined bamboo and medium density fiberboard and its manufacturing method

technical field

The invention relates to a novel composite structural panel for structure and a manufacturing method thereof, in particular to a composite structural panel of recombined bamboo and medium-density fiberboard and a manufacturing method thereof, belonging to the technical field of wood-based panel manufacturing in the wood/bamboo industry.

Background technique

As a characteristic and advantageous resource in my country, bamboo has the characteristics of high strength and good toughness. It has always been considered as an ideal structural material and has been widely used, such as bamboo plywood for car floor and building formwork. However, due to the lack of dedicated automatic mechanical processing equipment, most of the processes (such as breaking bamboo strips, weaving curtains and mats, etc.) still remain in the manual production stage for a long time, and cannot form large-scale continuous production. The development of recombined bamboo products not only improves the utilization rate of raw materials, but also realizes the industrial production and application of bamboo structural materials.

Bamboo-wood composite structural panels are one of the common panel products in the wood industry at present. They are mainly prepared by compounding wood rotary-cut veneer and bamboo curtain and bamboo mat. Due to the complementary advantages of wood and bamboo, the panels show good mechanical properties. , is currently widely used. But the raw material utilization rate of wood rotary-cut veneer and bamboo screen bamboo mat is very low, and the wood rotary-cut veneer has only about 60% of the output rate, and the bamboo screen and bamboo mat plywood output rate is even lower than 50%. And whether it is unit processing or plate making, the processing technology is relatively complicated, labor-intensive, and the quality controllability is not high. Therefore, problems such as improving the yield rate, reducing waste, simplifying the process, and ensuring stable product performance need to be solved urgently.

As a product that effectively utilizes wood resources, fiberboard not only has the original physical and mechanical properties of wood, but also overcomes the natural defects of wood, so it has a wide range of uses and is a good material for furniture, packaging, vehicles, buildings, ships, etc. The horizontal and vertical strength of wood or bamboo differs by several times or ten times, while the fiberboard has uniform fiber distribution, the difference in the product’s horizontal and vertical strength does not exceed 10%, and the vertical and horizontal drying shrinkage of the fiberboard has small changes and good dimensional stability. Especially medium density fiberboard, the density is close to natural wood, the surface is smooth and smooth, which is convenient for machining and decorative decoration, and its output is relatively high in our country. Therefore, if MDF and recombined bamboo can be combined to manufacture new structural panels, it will not only improve the strength-to-weight ratio of the board through the complementary properties of bamboo and wood fibers, but also expand the scope of application of MDF, and promote the recombination of bamboo and MDF. Continued product development. Composite board products can be used as medium-to-high-end building materials for the manufacture of high-end building clear water formwork and small and medium-sized structural components (such as doors and windows, indoor and outdoor floors, stairs, cladding panels, etc.), to meet the needs of the structural material market.

Contents of the invention

In order to solve the above-mentioned technical problems, the object of the present invention is to provide a composite structural board. A new type of composite structural board is obtained by combining recombined bamboo and medium density fiberboard, which has good mechanical properties and can adapt to different application requirements.

The object of the present invention is also to provide a method for manufacturing the above-mentioned composite structural panel.

In order to achieve the above object, the present invention provides a composite structure board of recombined bamboo and medium density fiberboard, which is composed of at least one layer of recombined bamboo and at least one layer of medium density fiberboard, and its thickness is 7-90mm.

The composite structural plate provided by the present invention may have a structure in which two layers, three layers or more layers are composited and then glued together. According to a specific embodiment of the present invention, preferably, the composite structural board is composed of a layer of restructured bamboo and a layer of medium density fiberboard; glued to form structural timber; or, the composite structural board is composed of one layer of medium density fiberboard as the core layer and two layers of reconstituted bamboo as the surface layer, wherein the two layers of reconstituted bamboo are respectively located on the two sides of the medium density fiberboard; or, the The composite structural board is composed of one layer of recombined bamboo as the core layer and two layers of medium density fiberboard as the surface layer, wherein the two layers of medium density fiberboard are respectively located on the two sides of the restructured bamboo.

The above-mentioned recombined bamboo and medium density fiberboard composite structural board provided by the present invention can be obtained by sizing, forming blanks, cold pressing, and curing. According to a specific embodiment of the present invention, the composite structural board is manufactured through the following steps:

Coating weather-resistant glue on both sides or one side of the contact surface between recombined bamboo and medium density fiberboard;

Assembling the recombined bamboo material coated with weather-resistant glue and medium density fiberboard to obtain a slab;

Press the slab, and after the pressing is completed, reduce the pressure in stages to relieve the pressure;

After the pressure is relieved, health preservation is carried out to obtain the above-mentioned composite structural board of recombined bamboo and medium density fiberboard.

The present invention selects medium-density fiberboard with uniform material, small difference in vertical and horizontal strength, not easy to crack, and can be easily surface decorated, and has excellent anti-ultraviolet performance, and its elastic modulus, compressive strength, and low-temperature anti-freeze storage performance are all better than those of other materials. The recombined bamboo of a tropical rainforest broad-leaved hardwood and East African hardwood is used as raw materials, and the prepared recombined bamboo and medium density fiberboard composite structural board can be used as a medium-to-high-grade building material for the manufacture of high-grade building formwork and small and medium-sized structural components (such as doors, windows, indoors, etc.) exterior floors, stairs, sheathing panels, etc.).

The technical solution provided by the present invention uses recombined bamboo and medium density fiberboard to prepare composite structural boards, on the one hand, it can expand the utilization of bamboo and wood resources, and increase the added value of products; Composite preparation of structural boards with medium-density fiberboards is to combine structural units with a specific thickness with a small number of layers to obtain excellent structural properties, which can realize industrial continuous production, greatly improve production efficiency, reduce production costs, and expand products. scope and field of use.

The present invention also provides a manufacturing method of the above-mentioned recombined bamboo and medium density fiberboard composite structural board, which comprises the following steps:

Coating weather-resistant glue on recombined bamboo and medium-density fiberboard, wherein, the contact surface between the restructured bamboo and medium-density fiberboard is coated with weather-resistant glue respectively, or coated with weather-resistant glue on one side of the contact surface of the two components Sex gel;

Assembling the recombined bamboo and medium density fiberboard coated with weather-resistant glue to obtain a slab;

Press the slab, and after the pressing is completed, perform step-by-step decompression and pressure relief;

After the pressure is relieved, health preservation is carried out to obtain a composite structural board of recombined bamboo and medium density fiberboard.

In the above-mentioned manufacturing method provided by the present invention, the specific operations of sizing, compacting, cold pressing and curing can be carried out in a conventional manner in the field, and the process parameters are carried out according to the process parameters provided by the present invention. The contact surface in the sizing step refers to the combined surface of the restructured bamboo and the medium density fiberboard during blank assembly. After the health care treatment, the products can also be aged, surface treated, graded, tested and so on.

According to a specific embodiment of the present invention, preferably, in the sizing process, the following specific forms can be adopted: use the recombined bamboo material coated with one side as the base material, and glue it with the medium density fiberboard coated with one side to obtain a two-layer structure The recombined bamboo and medium density fiberboard composite structural board; or, using a double-layer combination of one layer of recombined bamboo and one layer of medium density fiberboard as a structural unit, the composite structural material of recombined bamboo and medium density fiberboard is obtained through multi-layer gluing; or, with The double-sided glued medium density fiberboard is used as the core layer, and a layer of single-sided glued recombined bamboo is glued on the upper and lower sides as the surface layer to obtain a three-layer structure of recombined bamboo and medium density fiberboard composite structural board; or, double-sided coated The glued recombined bamboo is used as the core layer, and a layer of single-sided glued medium density fiberboard is glued on the upper and lower sides respectively, so as to obtain a three-layer structure of restructured bamboo and medium density fiberboard composite structural board. Before gluing, the reconstituted bamboo should be processed as necessary, such as thickness sanding.

In the above-mentioned manufacturing method provided according to the present invention, preferably, the weather-resistant glue used is one or more combinations of isocyanate glue, phenolic resin glue, and resorcinol resin glue, etc., and the glue coating of the weather-resistant glue The amount can be controlled to be 75-130g/m ² , based on the area of the glued surface. Among the weather-resistant glues used in the present invention, isocyanate glue is preferred, and the isocyanate glue can react with the moisture in the material to form polyurea. The generation of polyurea is conducive to the bonding of material units. By using the isocyanate glue, it can Make the composite structural board have better bonding strength and durability.

In the above-mentioned manufacturing method provided by the present invention, preferably, the curing time is controlled to be 24 hours.

In the above-mentioned manufacturing method provided by the present invention, preferably, the pressing is carried out at a unit pressure of 1-2 MPa (in terms of the area of the pressure-receiving surface), and the holding time is controlled to be 2 hours. The pressure relief is performed directly after the pressing is completed.

The recombined bamboo and medium-density fiberboard composite structural board provided by the invention and its manufacturing method have the following advantages:

1. The present invention adopts recombined bamboo and medium density fiberboard, two kinds of materials with mature production technology and continuous process, as the structural unit, and obtains the composite structural board of recombined bamboo and medium density fiberboard through scientific design, reasonable formation and cold pressing, without drying raw materials , The process is simplified, and the two structural units with a specific thickness are combined with a small number of layers, so that the product performance is controllable and the production efficiency is high;

2. The physical and mechanical strength indicators of the recombined bamboo and medium density fiberboard composite structural panels provided by the present invention can meet the relevant standard requirements for structural panels such as building doors and windows, templates, cladding panels and floors at home and abroad;

3. The recombined bamboo and medium-density fiberboard composite structural board provided by the present invention has a wide range of applications, which not only effectively drives the value-added utilization of bamboo resources, improves the utilization rate of raw materials, but also adds a utilization path for my country's medium-density fiberboard, improving Applied value;

4. The manufacturing method adopted in the present invention is simple and efficient, and the energy-saving effect is remarkable, which simplifies the production process of the composite structural board of recombined bamboo and medium-density fiberboard, and the technical transformation cost in the actual industrialization process is low, and the product cost is controllable and greatly reduced. For example, compared with the cost of container floors produced from cloned wood, the cost is reduced by about 20%;

5. The recombined bamboo and medium-density fiberboard composite structural board provided by the present invention can be used to prepare small and medium-sized building components indoors and outdoors, such as doors and windows, floors and stairs, etc., which can make full use of the high strength and excellent outdoor performance of recombined bamboo, and Fiberboard has the characteristics of good impact resistance and easy processing, and it can replace metal/fossil derivatives such as plastic steel and aluminum alloy, which has a positive impact on reducing global carbon emissions.

Description of drawings

Fig. 1 is the schematic structural representation of the composite structure plate that embodiment 1 provides;

Fig. 2 is the schematic structural representation of the composite structure plate that embodiment 2 provides;

FIG. 3 is a schematic structural view of the composite structural panel provided in Example 3. FIG.

Explanation of main figures and symbols:

MDF 1 Reconstituted Bamboo 2

Detailed ways

In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

Example 1

This embodiment provides a composite structural panel of recombined bamboo and medium density fiberboard, which can be used to manufacture doors and windows (such as double-layered doors and windows), and the structure is shown in FIG. 1 . The boards used in the composite structure board are medium density fiberboard 1 produced from wood fiber (single tree species or mixed tree species with similar properties) and recombined bamboo material 2 obtained by dipping and molding bamboo tow (Moso bamboo or Ci bamboo).

The structure of the composite structural board provided in this embodiment is based on recombined bamboo 2, and the upper layer is glued with a medium density fiberboard 1 coated with isocyanate glue on one side, which is manufactured according to the following steps:

Material selection: use medium density fiberboard with a thickness of 20mm and 25mm, with a density of 0.75g/cm ³ and a moisture content of 8%; use reconstituted bamboo with a density of 1.05g/cm ³ and a moisture content of 10%, and sand it to a thickness of 15mm , 20mm, 25mm;

Glue sizing: apply isocyanate glue on one side of the medium density fiberboard and recombined bamboo, and the amount of glue applied is 130g/m ² ;

Blank assembly: combine recombined bamboo and medium density fiberboard together to obtain three different slabs. The total thickness of the slabs is controlled to 35mm (20mm thick medium density fiberboard + 15mm thick recombined bamboo), 40mm (20mm thick medium density fiberboard + 20mm thick recombined bamboo) and 50mm (25mm thick medium density fiberboard + 25mm thick recombined bamboo), and the thickness deviation is ± 1mm;

Pressure application: The slab is pressed under the unit pressure condition of 1.2MPa, and the pressure holding time is 2 hours. After the pressing is completed, the pressure is released directly, and then the health is maintained for 24 hours.

After aging, surface treatment, grading, and testing of the cured slabs, a composite structural panel of recombined bamboo and medium density fiberboard is obtained, and its physical and mechanical properties are as follows:

Moisture content: ≤10%

Bend along: ≤1.5‰

Distortion, diagonal difference: ≤1.5mm

Bonding strength: ≥0.5MPa

Shear strength along the grain of glue seam (longitudinal): ≥8.0N/mm ²

The test of the above parameters is carried out according to the method in the "Building Wooden Doors and Windows" (JG/T122-2000) standard, and all parameters meet the index requirements.

The recombined bamboo and medium-density fiberboard composite structural board provided in this embodiment is suitable for manufacturing double-layer structure doors and windows, and the recombined bamboo layer with excellent natural durability can be used as the outside of the door and window to play the role of main frame support and directly contact with the outdoor environment; As the inner side of doors and windows, medium density fiberboard can be placed in the indoor environment. It can not only use its good surface processing performance to enhance the interior decoration effect with various surface shapes, but also reduce the weight of doors and windows and reduce the cost of raw materials.

Example 2

This embodiment provides a composite structural board of recombined bamboo and medium density fiberboard, which can be used to manufacture floors, and its structure is shown in FIG. 2 . The boards used in the composite structure board are medium density fiberboard 1 produced from wood fiber (single tree species or mixed tree species with similar properties) and recombined bamboo material 2 obtained by dipping and molding bamboo tow (Moso bamboo or Ci bamboo).

The structure of the composite structure board provided by this embodiment is a medium density fiberboard 1 coated with isocyanate glue on both sides as the core layer, and a layer of recombined bamboo 2 coated with isocyanate glue on one side is glued to the top and bottom of it. It is manufactured according to the following steps of:

Material selection: use 9mm thick medium density fiberboard with a density of 0.75g/cm ³ and a moisture content of 8%; select reconstituted bamboo with a density of 1.05g/cm ³ and a moisture content of 10%, and sand it to a thickness of 3mm;

Glue sizing: apply isocyanate glue on both sides of one layer of medium density fiberboard, and apply isocyanate glue on one side of two layers of reconstituted bamboo respectively, the amount of glue applied is 130g/m ² ;

Blank assembly: use double-sided glued medium density fiberboard as the core layer, and two layers of single-sided glued reconstituted bamboo surface layer to form blanks to obtain slabs. The total thickness of the slabs is controlled at 15mm, and the thickness deviation is ±0.5mm;

Pressure application: The slab is pressed under the pressure condition of 1.2MPa, and the holding time is 2 hours. After the pressing is completed, the pressure is released directly, and then the health is maintained for 24 hours.

After aging, surface treatment, grading, and testing of the cured slabs, a composite structural panel of recombined bamboo and medium density fiberboard is obtained, and its physical and mechanical properties are as follows:

Moisture content: 4% to 16%

Coefficient of wet friction: 0.3～0.8

Bending load after cyclic treatment: ≥220N

The detection of the above parameters is carried out according to the standard of LY/T1861-2009 "wooden floor for outdoor use". Reconstituted bamboo can be widely used for flooring due to its excellent durability, strength, and low shrinkage and expansion rate. In this example, medium-density fiberboard with soft material and low density is composited with recombined bamboo, and the composite structural board obtained is suitable for making bamboo-wood composite flooring. It can effectively reduce the density of floor substrates while meeting product standard requirements, and reduce the cost.

Example 3

This embodiment provides a composite structural panel of recombined bamboo and medium density fiberboard, which can be used to manufacture building formwork, the structure of which is shown in Figure 2. The boards used in the composite structure board are medium density fiberboard 1 produced from wood fiber (single tree species or mixed tree species with similar properties) and recombined bamboo material 2 obtained by dipping and molding bamboo tow (Moso bamboo or Ci bamboo).

The structure of the composite structure board provided by this embodiment is a medium density fiberboard 1 coated with isocyanate glue on both sides as the core layer, and a layer of recombined bamboo 2 coated with isocyanate glue on one side is glued to the top and bottom of it. It is manufactured according to the following steps of:

Material selection: use 10mm thick medium density fiberboard with a density of 0.75g/cm ³ and a moisture content of 8%; use reconstituted bamboo with a density of 1.05g/cm ³ and a moisture content of 10%, and sand it to a thickness of 4mm;

Glue sizing: apply isocyanate glue on both sides of one layer of medium density fiberboard, and apply isocyanate glue on one side of two layers of reconstituted bamboo respectively, the amount of glue applied is 130g/m ² ;

Blank assembly: use double-sided glued medium density fiberboard as the core layer, and two layers of single-sided glued reconstituted bamboo surface layer to form three different slabs. The thickness of the slabs is controlled to be 18mm, and the thickness deviation is ± 0.8mm;

Pressure application: The slab is pressed under the pressure condition of 1.2MPa, and the holding time is 2 hours. After the pressing is completed, the pressure is released directly, and then the health is maintained for 24 hours.

After aging, surface treatment, grading, and testing of the cured slabs, a composite structural panel of recombined bamboo and medium density fiberboard is obtained, and its physical and mechanical properties are as follows:

Moisture content: 5%～12%

MOR _// : ≥100MPa

MOR _⊥ : ≥50MPa

MOE _// : ≥8000MPa

MOE _⊥ : ≥4000MPa

The detection of the above parameters can be carried out according to the method in "Bamboo Plywood for Concrete Formwork" (LY/T1574-2000), and all parameters can meet the requirements of the above standards.

Example 4

This embodiment provides a composite structural panel of recombined bamboo and medium density fiberboard, which can be used to manufacture cladding panels and stair components of wooden structures. The structure is shown in Figure 3 . The boards used in the composite structure board are medium density fiberboard 1 produced from wood fiber (single tree species or mixed tree species with similar properties) and recombined bamboo material 2 obtained by dipping and molding bamboo tow (Moso bamboo or Ci bamboo).

The structure of the composite structural board provided by this embodiment is to use the recombined bamboo material 2 coated with isocyanate glue on both sides as the core layer, and then glue a layer of medium density fiberboard 1 coated on one side with isocyanate glue on the upper and lower sides. It is manufactured according to the following steps of:

Material selection: use 6mm thick medium density fiberboard with a density of 0.75g/cm ³ and a moisture content of 8%; select reconstituted bamboo with a density of 1.05g/cm ³ and a moisture content of 10%, and sand it to a thickness of 6mm;

Glue sizing: apply isocyanate glue on both sides of a layer of reconstituted bamboo, and apply isocyanate glue on one side of two layers of medium density fiberboard respectively. The amount of glue applied is 125g/m ² ;

Blank assembly: use double-sided glued recombined bamboo as the core layer, and two layers of single-sided glued medium density fiberboard as the blank to obtain four different slabs. The thickness of the slabs is controlled to be 18mm, and the thickness deviation is ± 0.5mm;

Pressure application: The slab is pressed under the pressure condition of 1.2MPa, and the holding time is 2 hours. After the pressing is completed, the pressure is released directly, and the health is maintained for 24 hours.

After aging, surface treatment, grading, and testing of the cured slabs, a composite structural panel of recombined bamboo and medium density fiberboard is obtained, and its physical and mechanical properties are as follows:

Moisture content: 5%～13%

MOR _// : ≥90MPa

MOR _⊥ : ≥40MPa

MOE _// : ≥7000MPa

MOE _⊥ : ≥3000MPa

Horizontal shear strength: ≥3MPa

Formaldehyde release limit: ≤1.5mg/L

Concentrated static load: ≥1.8kN

Impact load: ≥120N·m

Minimum ultimate load under uniform load: ≥13kPa

Maximum deflection under uniform load: ≤2.4mm

The above parameters can be tested in accordance with "Bamboo-Wood Composite Panels for Structures" (GB/T21128-2007), "Code for Construction Quality Acceptance of Wooden Structure Engineering" (GB50206-2002) and "Methods in Standards for Wooden Structure Test Methods" (GB/T21128-2007). T50329-2002), and all parameters can meet the requirements of the above-mentioned standards.

The recombined bamboo and medium-density fiberboard composite structural board provided in this embodiment is suitable for preparing parts such as wood structure building cladding panels and stair treads. Effectively enhance the impact toughness of wall panels and stairs; on the other hand, using MDF as a panel reduces the surface hardness of the board. Compared with pure bamboo boards, it is not only easier to nail, but also reduces the hardness of the board to a certain extent. Weight and cost of raw materials.

Claims (10)

1. A composite structure board of recombined bamboo and medium density fiberboard, which is composed of at least one layer of recombined bamboo and at least one layer of medium density fiberboard, and its thickness is 7-90mm. 2. The composite structure board according to claim 1, wherein, the composite structure board consists of one layer of medium density fiberboard as the core layer and two layers of recombined bamboo as the surface layer, wherein the two layers of recombined bamboo are respectively located in the Both sides of MDF. 3. The composite structure board according to claim 1, wherein, the composite structure board is made up of one layer of recombined bamboo as the core layer and two layers of medium density fiberboard as the surface layer, wherein the two layers of medium density fiberboard are respectively located in the Both surfaces of reconstituted bamboo. 4. The composite structural panel according to claim 1, wherein the composite structural panel is composed of a layer of reconstituted bamboo and a layer of medium density fiberboard, or a combination thereof is used as a structural unit, and the structural material is formed by multi-layer gluing. 5. The composite structural panel according to claims 2-4, which is manufactured by the following steps: Coating weather-resistant glue on both sides or one side of the contact surface between recombined bamboo and medium density fiberboard; Assembling the recombined bamboo material coated with weather-resistant glue and medium density fiberboard to obtain a slab; Carry out cold pressing to the slab, and release the pressure after the pressing is completed; After the pressure is relieved, health preservation is carried out to obtain the composite structural board of the recombined bamboo and medium density fiberboard. 6. the manufacture method of the recombined bamboo and medium-density fiberboard composite structure board described in any one of claims 1 to 5, it may further comprise the steps: Coating weather-resistant glue on the restructured bamboo and medium-density fiberboard, wherein the contact surface between the restructured bamboo and the medium-density fiberboard is coated with weather-resistant glue or coated with weather-resistant glue on one side of the contact surface; Assembling the recombined bamboo and medium density fiberboard coated with weather-resistant glue to obtain a slab; The slab is cold pressed, and after the pressing is completed, the pressure is relieved in stages; After the pressure is relieved, health preservation is carried out to obtain the composite structural board of the recombined bamboo and medium density fiberboard. 7. The manufacturing method according to claim 6, wherein the weather-resistant glue is one or a combination of isocyanate glue, phenolic resin glue and resorcinol resin glue. 8 . The manufacturing method according to claim 6 , wherein the amount of the weather-resistant glue applied is 75˜130 g/m ² . 9. The manufacturing method according to claim 6, wherein the curing time is 24 hours. 10. The manufacturing method according to claim 6, wherein the pressing is carried out under a pressure of 1-2 MPa, and the holding time is 2 hours.

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