Bamboo Expanded Multilayer Board

Abstract

The utility model belongs to the technical field of bamboo materials, and specifically relates to a bamboo unfolded multilayer board. The bamboo unfolded multilayer board comprises at least two stacked bamboo sheet layers prepared from bamboo unfolded boards, wherein the bamboo sheet layer comprises at least two mutually spliced ​​bamboo sheets, the bamboo fiber directions of the bamboo sheets of two adjacent bamboo sheet layers intersect, and the density difference between the bamboo sheets in the same layer is ≤200kg / m 3 The bamboo unfolded multilayer board has stable physical properties and is not prone to deformation even if its width increases. It also has high production efficiency and is more environmentally friendly.

Description

Technical Field

[0001] The utility model belongs to the technical field of bamboo materials, and in particular relates to an unfolded bamboo multilayer board. Background Art

[0002] Traditional bamboo flat-pressed composite boards are prone to deformation when the size increases due to the unique characteristics of bamboo such as fiber direction and uneven density distribution. The larger the size, the more serious the deformation. When the traditional same-direction plywood is affected by a dry or humid environment, it will also cause inconsistent shrinkage or expansion rates, resulting in cracking, making it impossible to produce large-sized boards, which restricts the application of bamboo. Although there are some large-sized bamboo composite boards on the market, these bamboo composite boards (bamboo multilayer boards) are mostly spliced ​​with small-sized raw materials or arranged vertically in the longitudinal direction. For example, a bamboo laminate disclosed in the Chinese patent with announcement number CN2361726Y uses a longitudinal vertical arrangement. If this type of splicing structure is to achieve the production of large-sized boards, a large amount of glue must be used in the splicing process, which does not meet the characteristics of bamboo being sustainable, renewable and truly environmentally friendly. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a bamboo unfolded multilayer board which can use wide raw materials and uses less glue.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is as follows: the bamboo unfolded multilayer board comprises at least two stacked bamboo layers, the bamboo layer comprises at least two bamboo pieces spliced ​​to each other, the bamboo fiber directions of the bamboo pieces of the two adjacent bamboo layers intersect, and the density difference between the bamboo pieces in the same layer is ≤200kg / m 3 .

[0005] Among them, the density difference between different bamboo pieces between layers is ≤200kg / m 3 .

[0006] The thickness of the bamboo strips is 0.5 to 4 mm, preferably 0.5 to 3 mm.

[0007] The width of the bamboo strips is ≥50 mm, preferably 50-200 mm.

[0008] The length of the bamboo strips is 1 to 4 m, preferably 1.5 to 2.5 m.

[0009] Among them, the directions of bamboo fibers in the bamboo pieces on the same layer are parallel to each other.

[0010] The directions of bamboo fibers of two adjacent bamboo slice layers are perpendicular to each other.

[0011] Wherein, bonding layers are arranged between the bamboo sheet layers.

[0012] Among them, the number of bamboo sheet layers is an odd number.

[0013] The thickness of the bamboo sheet layers located at the uppermost layer and the lowermost layer is smaller than the thickness of the bamboo sheet layers located between the uppermost layer and the lowermost layer.

[0014] The utility model has the beneficial effect that the bamboo unfolded multilayer board provided by the utility model controls the density between the interlayer bamboo pieces and selects bamboo pieces with similar density to make the multilayer board, thereby overcoming the problem of poor structural stability caused by the strength difference and uneven density distribution of bamboo itself, that is, the multilayer board is easy to deform, and the bamboo fiber directions of the bamboo pieces of the two adjacent bamboo pieces intersect, so that the horizontal grain direction of one layer of bamboo pieces in the two adjacent layers will not crack due to shrinkage or expansion under the protection of the high tensile strength of the bamboo fiber of the other layer, thereby obtaining a composite bamboo material with better physical properties and more uniformity. At the same time, the width of the splicing can be increased to prepare a bamboo multilayer board with a larger width and less deformation, which can greatly reduce the use of glue and obtain a more environmentally friendly composite bamboo material. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the dissected structure of a bamboo unfolded multilayer board according to a specific embodiment of the utility model;

[0016] Figure 2 It is a schematic diagram of the partial dissection structure of the bamboo unfolded multilayer board according to the specific implementation mode of the utility model. DETAILED DESCRIPTION

[0017] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0018] Please refer to Figure 1 as well as Figure 2 The bamboo unfolded multilayer board comprises at least two stacked bamboo layers, wherein the bamboo layer comprises at least two bamboo pieces spliced ​​to each other, the bamboo fibers of the bamboo pieces of two adjacent bamboo layers intersect, and the density difference between the bamboo pieces in the same layer is ≤200kg / m 3 .

[0019] The splicing method may be finger-joining or other splicing methods commonly used in the field of other bamboo materials.

[0020] From the above description, it can be seen that the beneficial effect of the utility model is that bamboo chips are made from bamboo unfolded boards, and planing, rotary cutting and other methods can be used. The density difference of the obtained bamboo chips is smaller than that of the bamboo unfolded boards. By screening bamboo chips with similar density and then compounding them into multi-layer boards, the problem of multi-layer boards being easy to deform as the size increases can be avoided, and then bamboo multi-layer boards with larger width and less deformation can be prepared, thereby expanding the application field of bamboo multi-layer boards.

[0021] Furthermore, the density difference between different bamboo pieces between layers is ≤200kg / m3 .

[0022] From the above description, it can be seen that by further controlling the density of the bamboo strips between the layers, the density difference of the bamboo strips used in the same multilayer board is within 200kg / m 3 Within (such as density difference of 200kg / m 3 , 150kg / m 3 , 100kg / m 3 , 50kg / m 3 、30kg / m 3 Etc.), which can effectively avoid the different shrinkage and expansion rates caused by different densities, which can easily cause tile-like deformation.

[0023] Furthermore, the thickness of the bamboo piece is 0.5-4 mm, preferably 0.5-3 mm, and more preferably 2-3 mm.

[0024] From the above description, it can be seen that the bamboo pieces of the above thickness are different from the thicker bamboo boards conventionally used to make multi-layer bamboo boards. The density difference within a single layer is smaller, the density is more uniform, and it is not easy to deform after being made into multi-layer bamboo boards later.

[0025] Furthermore, the width of the bamboo strips is ≥50 mm, preferably 50-200 mm.

[0026] From the above description, it can be seen that the width of the single piece of raw material currently used in the market for preparing multi-layer bamboo boards is mostly less than 30 mm, and the width of the multi-layer boards produced is also small. The utility model reduces the single layer thickness of the bamboo unfolded board, reduces the density difference, and increases the width to ensure that a wide bamboo unfolded multi-layer board with stable performance that is not easy to deform is prepared. And using wide bamboo pieces for processing can significantly improve the processing efficiency.

[0027] Furthermore, the length of the bamboo strip is 1 to 4 m, preferably 1.5 to 2.5 m.

[0028] Furthermore, directions of bamboo fibers of bamboo pieces in the same layer are parallel to each other.

[0029] From the above description, it can be seen that the bamboo fibers of the bamboo pieces in the same layer are parallel to each other, which is conducive to widening.

[0030] Furthermore, directions of bamboo fibers of two adjacent layers of bamboo sheets are perpendicular to each other.

[0031] From the above description, it can be seen that when the layers are stacked, the directions of the bamboo fibers of the two adjacent layers are preferably not parallel to each other, but intersecting, that is, at a certain angle, preferably 90°, that is, the directions of the bamboo fibers of the two adjacent layers are perpendicular to each other, so that when they are in a dry or humid environment, it is beneficial to improve the physical properties and stability of the overall board after composite.

[0032] Furthermore, an adhesive layer is provided between the bamboo sheet layers. The adhesive layer is composed of glue and is used to bond (attach) the upper and lower bamboo sheet layers.

[0033] Furthermore, the number of the bamboo slice layers is an odd number. Furthermore, the bamboo fibers of the bamboo slices located in the uppermost layer and the lowermost layer have the same direction.

[0034] From the above description, it can be seen that the setting of an odd number of layers can make the directions of the bamboo fibers in the uppermost layer and the lowermost layer consistent, thereby making the specifications of the manufactured multi-layer board more uniform.

[0035] Please refer to Figure 1 and 2 , Embodiment 1 of the present utility model is:

[0036] The bamboo unfolded multilayer board comprises 6 stacked bamboo layers, each bamboo layer is formed by splicing 20 bamboo pieces with a width of 50 mm, a length of 1 m and a thickness of 2 mm (only part is shown in the figure), the splicing direction is perpendicular to the fiber direction of the bamboo pieces, the fiber directions of the bamboo pieces in the same bamboo layer are the same, the fiber directions of the bamboo pieces in two adjacent bamboo layers are perpendicular to each other (i.e. the intersection angle is 90°), and the density difference between the bamboo pieces is 50 kg / m 3 The bamboo sheet layers are bonded together by an adhesive layer composed of glue, and after cutting, a bamboo unfolded multilayer board with a thickness of 12 mm is obtained.

[0037] The bamboo strips are obtained by slicing, peeling, etc. of the bamboo unfolded board, and the splicing method is finger jointing.

[0038] Example 2: The only difference from Example 1 is that 5 bamboo sheet layers are included. A bamboo unfolded multilayer board with a thickness of 10 mm is obtained.

[0039] Example 3: The only difference from Example 1 is that 4 bamboo sheet layers are included. A bamboo unfolded multilayer board with a thickness of 8 mm is obtained.

[0040] Example 4: The only difference from Example 1 is that it includes 3 bamboo sheet layers. A bamboo unfolded multilayer board with a thickness of 6 mm is obtained.

[0041] The density and radial static bending strength (MOR) of the bamboo unfolded multilayer boards of Examples 1 to 4 were tested, and the results are shown in Table 1.

[0042] Table 1

[0043]

[0044] Embodiment 5:

[0045] The bamboo unfolded multilayer board comprises 7 stacked bamboo layers, each bamboo layer is formed by splicing 6 bamboo pieces with a width of 200 mm, a length of 1.5 m and a thickness of 1.5 mm, the splicing direction is perpendicular to the fiber direction of the bamboo pieces, the fiber directions of the bamboo pieces in the same bamboo layer are the same, the fiber directions of the bamboo pieces in two adjacent bamboo layers are perpendicular to each other, and the density difference between the bamboo pieces is 50-100 kg / m 3 The bamboo sheet layers are bonded together by an adhesive layer composed of glue, and after cutting, a bamboo unfolded multilayer board with a thickness of 10.5 mm is obtained.

[0046] Embodiment 6:

[0047] The bamboo unfolded multilayer board comprises 5 stacked bamboo layers, each bamboo layer is formed by splicing 40 bamboo pieces with a width of 100 mm, a length of 4 m and a thickness of 4 mm, the splicing direction is perpendicular to the fiber direction of the bamboo pieces, the fiber directions of the bamboo pieces in the same bamboo layer are the same, the fiber directions of the bamboo pieces in two adjacent bamboo layers are perpendicular to each other, and the density difference between the bamboo pieces is 150-200 kg / m 3 The bamboo sheet layers are bonded together by an adhesive layer composed of glue, and after cutting, a bamboo unfolded multilayer board with a thickness of 20 mm is obtained.

[0048] Embodiment 7:

[0049] The bamboo unfolded multilayer board comprises 9 stacked bamboo layers, each bamboo layer is formed by splicing 30 bamboo pieces with a width of 70 mm, a length of 2.5 m and a thickness of 3 mm, the splicing direction is perpendicular to the fiber direction of the bamboo pieces, the fiber directions of the bamboo pieces in the same bamboo layer are the same, the fiber directions of the bamboo pieces in two adjacent bamboo layers are perpendicular to each other, and the density difference between the bamboo pieces is 80 kg / m 3 The bamboo sheet layers are bonded together by an adhesive layer composed of glue, and after cutting, a bamboo unfolded multilayer board with a thickness of 27 mm is obtained.

[0050] Embodiment 8:

[0051] The bamboo unfolded multilayer board comprises 15 stacked bamboo layers, each bamboo layer is formed by splicing 25 bamboo pieces with a width of 80 mm, a length of 2 m and a thickness of 0.5 mm, the splicing direction is perpendicular to the fiber direction of the bamboo pieces, the fiber directions of the bamboo pieces in the same bamboo layer are the same, the fiber directions of the bamboo pieces in two adjacent bamboo layers are perpendicular to each other, and the density difference between the bamboo pieces is ≤110 kg / m 3 The bamboo sheet layers are bonded together by an adhesive layer composed of glue, and after cutting, a bamboo unfolded multilayer board with a thickness of 7.5 mm is obtained.

[0052] Embodiment 9:

[0053] The only difference from Example 1 is that the 6 bamboo layers are grouped in pairs, the two bamboo layers in the group are opposite to each other on the sides close to the bamboo yellow, and the bamboo fibers of the two bamboo layers in the group have the same direction; the fiber directions of the bamboo sheets of two adjacent bamboo layers between the groups are perpendicular to each other.

[0054] In Example 9, since there are still density differences in the bamboo pieces themselves, the fibers of the bamboo pieces are stacked and bonded in pairs within the group with the same direction, and the fibers between the groups are staggered in direction. The bamboo pieces within the group are stacked against each other with the fibers in the same direction as the basic unit of invisible variable stress, and the flatness of the largest-format bamboo unfolded multilayer board can be ensured after the finished product is made.

[0055] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. Bamboo unfolded multilayer board, characterized in that, The bamboo sheet comprises at least two stacked bamboo sheets, wherein the bamboo sheet layer comprises at least two bamboo sheets spliced ​​to each other, the bamboo fiber directions of the bamboo sheets of two adjacent bamboo sheet layers intersect, and the density difference between the bamboo sheets in the same layer is ≤200kg / m 3 .

2. The bamboo unfolded multilayer board according to claim 1, characterized in that: The density difference between the bamboo pieces in different layers is ≤200kg / m 3 .

3. The bamboo unfolded multilayer board according to claim 1, characterized in that: The thickness of the bamboo piece is 0.5-4 mm.

4. The bamboo unfolded multilayer board according to claim 1, characterized in that: The width of the bamboo strips is ≥50 mm.

5. The bamboo unfolded multilayer board according to claim 1, characterized in that: The length of the bamboo strips is 1 to 4 meters.

6. The bamboo unfolded multilayer board according to claim 1, characterized in that: The bamboo fibers of the bamboo pieces in the same layer are parallel to each other.

7. The bamboo unfolded multilayer board according to claim 1, characterized in that: The directions of the bamboo fibers of the bamboo slices in two adjacent bamboo slice layers are perpendicular to each other.

8. The bamboo unfolded multilayer board according to claim 1, characterized in that: An adhesive layer is arranged between the bamboo sheet layers.

9. The bamboo unfolded multilayer board according to claim 1, characterized in that: The number of the bamboo sheet layers is an odd number.

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