Arc-modified bamboo chip processing method and arc-shaped original-state bamboo laminated timber

Abstract

The invention relates to an arc-modified bamboo chip processing method and an arc-shaped original-state bamboo laminated timber. The arc-modified bamboo chip processing method comprises the following steps that round bamboo tubes are cut off, grading is conducted according to the radian and the bamboo wall thickness, and graded round bamboo tubes are obtained; the graded round bamboo tube is subdivided in an equal arc length mode, and arc-shaped bamboo chips are obtained; the arc-shaped bamboo chips are subjected to steam and softening treatment; the softened bamboo chips are subjected to green and yellow removing and arc changing treatment, the initial radian of the bamboo chips is changed through a gradually-reduced arc-shaped pressing roller, the arc radius of the bamboo chips is decreased, and the arc-changed bamboo chips are obtained; and the arc-modified bamboo chips with the different radius grades are placed under different arc-shaped molds and are locked through a locking assembly for cooling and shaping, and the equal-arc bamboo chips with the different radius grades are obtained. By means of the method, the arc-shaped original-state bamboo laminated timber is obtained through processing. According to the arc-shaped original-state bamboo laminated timber manufactured through the method, the size stability of a final product is improved, and the cracking rate of the bamboo chips is reduced.

Description

Technical Field

[0001] The invention belongs to the field of material processing, and in particular relates to a method for processing arc-modified bamboo pieces and arc-shaped original bamboo laminated materials. Background Art

[0002] Bamboo has a short growth cycle, strong carbon fixation ability, and excellent mechanical properties. It is a sustainable crop resource and is often used in the production of bamboo engineering materials. However, due to the natural circular structure of bamboo, it cannot be directly processed into board materials for use. It needs to be processed into various bamboo units, such as standard bamboo strips, bamboo strips, bamboo silk, bamboo shavings, etc., and then glued and assembled into materials. This causes great damage to the original material, low material utilization, and high glue application. In order to reduce damage to bamboo, improve material utilization and reduce glue application, bamboo flattening technology has been developed and applied.

[0003] However, bamboo flattening technology requires high-precision equipment and professional operating skills, and it is difficult to achieve that the bamboo does not break or deform during the flattening process. In addition, there are many types of bamboo flattening equipment on the market, with different performances, and the operation is complicated, and the requirements for skilled workers are high. Therefore, the cost of bamboo flattening technology is relatively high. At the same time, although bamboo flattening technology can improve the utilization rate of bamboo, in practical applications, the utilization rate of bamboo is still subject to certain restrictions. On the one hand, due to the growth characteristics and structural characteristics of bamboo itself, it is easy to break and deform during the flattening process, which affects the yield and utilization rate of bamboo. On the other hand, different types of bamboo perform differently during the flattening process, and some bamboos are difficult to achieve the ideal flattening effect, which also limits the utilization rate of bamboo. Bamboo flattening technology consumes high energy during the processing process and also has a certain negative impact on the environment. Moreover, the flattening process changes the shape of bamboo pieces too much, and the residual stress inside the bamboo pieces is large, resulting in poor dimensional stability of the flattened bamboo pieces, easy warping, and cracking during the drying process.

[0004] In order to improve the utilization rate of bamboo without destroying its original state, CN 1970254A proposed a method for reorganizing the original arc of bamboo. The arc-shaped bamboo pieces are milled to make the inner and outer arc radii of the arc-shaped bamboo pieces equal or similar, and the arc-shaped original gluing of the bamboo pieces is achieved by pasting the green surface of the bamboo to the yellow surface of the bamboo. This method retains the natural gradient structure, arc characteristics and biomechanical strength of the bamboo. However, there are still some problems: after the original bamboo pieces are milled into equal-arc bamboo pieces, the yield rate is limited, and the width of the bamboo pieces is small (2-3 cm). The width specification of the laminated wood formed by the assembly and gluing is small, and its use is therefore limited. On the other hand, the arc-shaped original gluing of bamboo pieces is more complicated than the traditional straight bamboo piece processing technology. This is mainly reflected in the arc milling and gluing process, which requires precise control of parameters such as milling arc and gluing pressure to ensure product quality. This increases the technical difficulty and quality control requirements in the production process. Since the curved bamboo gluing technology requires the use of special equipment and processes, such as curved milling machines and precision gluing equipment, the purchase and maintenance costs of these equipment are relatively high. At the same time, due to the complexity of the process, the labor cost and time cost in the production process will also increase accordingly, resulting in a high overall production cost. Summary of the invention

[0005] The present invention aims at the problems of low bamboo utilization rate, poor dimensional stability, serious damage to the original state and high amount of glue in the processing of existing bamboo engineering materials, and proposes a method of preparing large-width equal-arc bamboo slices by high-temperature steam softening-removing green and yellow-changing, and at the same time, adopting two methods of wet gluing and dry gluing to prepare arc-shaped original bamboo laminates, so as to achieve efficient and original utilization of bamboo. The method can greatly improve the material utilization rate, improve the dimensional stability of the product, reduce the amount of glue, and realize multi-layer gluing of arc-shaped bamboo slices, which greatly broadens the application range of bamboo and provides a new way for the preparation of bamboo engineering materials.

[0006] According to one aspect of the present invention, a method for processing a bamboo strip with a modified arc is provided, which may include the following steps: - Cut the round bamboo tubes and grade them according to the curvature and bamboo wall thickness to obtain graded round bamboo tubes; - Split the graded round bamboo tube into equal arc lengths to obtain arc-shaped bamboo pieces; - Steam and soften the curved bamboo strips; - De-greening and de-yellowing the softened bamboo pieces and re-curving them, using gradually shrinking arc-shaped pressing rollers to change the initial curvature of the bamboo pieces, so that the arc radius of the bamboo pieces becomes smaller, thereby obtaining re-curved bamboo pieces; and - Place the curved bamboo pieces with different radius levels under different curved molds, and lock them through locking components to cool and shape them, so as to obtain equal-arc bamboo pieces with different radius levels.

[0007] According to an embodiment of the present invention, the round bamboo tube can be selected from 3-6 year old fresh bamboo tube with a moisture content of about 60%. After the round bamboo tube is cut, it can be divided into three grades according to the different radii of the round bamboo tube: 4-5cm, 5-6cm, and 6-7cm.

[0008] According to an embodiment of the present invention, when equal arc length splitting is performed, the arc length range may be 50-100 mm, and the length of the arc-shaped bamboo piece may be 60-240 cm.

[0009] According to an embodiment of the present invention, when the bamboo chips are softened, the steam pressure may be 1.0-1.1 MPa, and the saturated steam treatment time may be 320-440 seconds.

[0010] According to an embodiment of the present invention, the green and yellow removal and arc modification of the bamboo strips can be performed in sequence. The arc-shaped bamboo strips after the green and yellow removal can have their initial arc radius changed by a gradually shrinking arc pressure roller, so that the initial arc radius of the bamboo strips becomes smaller.

[0011] According to an embodiment of the present invention, the arc-shaped bamboo pieces with arc radii of 4-5cm, 5-6cm, and 6-7cm can be changed to arc radii of 3.8cm, 4.7cm, and 5.6cm, respectively.

[0012] According to the embodiment of the present invention, the curved bamboo pieces can be cooled and shaped, and the moisture content of the bamboo pieces can be reduced to about 30%.

[0013] According to an embodiment of the present invention, the curved bamboo piece can be placed under a curved mold to be cooled and shaped for 2 hours.

[0014] According to one aspect of the present invention, there is provided an arc-shaped original bamboo laminated material, which can be obtained by gluing equal-arc bamboo pieces obtained by the arc-modified bamboo piece processing method according to the present invention.

[0015] According to the embodiment of the present invention, the equal-arc bamboo pieces obtained by the arc-modified bamboo piece processing method of the present invention can be wet-glued when the bamboo pieces have a high moisture content, or can be dry-glued after the bamboo pieces are dried. Both gluing methods can prepare arc-shaped original bamboo laminated materials.

[0016] Furthermore, the wet gluing includes: gluing and assembling the curved bamboo pieces with a moisture content around the fiber saturation point in the form of bamboo green and bamboo yellow, and putting the assembled pieces into a press with a curved mold for cold pressing and gluing.

[0017] Furthermore, dry gluing includes: placing the curved bamboo pieces after shaping for 2 hours into a drying kiln for drying, reducing the moisture content of the bamboo pieces to about 10% and applying glue to assemble them in the form of bamboo green-bamboo yellow, and placing the assembled pieces into a press with a curved mold for gluing.

[0018] According to the embodiments of the present invention, the arc-shaped original bamboo laminated material prepared by the arc-changing bamboo chip processing method of the present invention retains the original gradient structure and mechanical strength of the bamboo material; the arc-changing bamboo chip processing method of the present invention reduces the arc radius rather than expands the arc during the arc-changing process, thereby offsetting the trend of the arc radius becoming larger due to the radial difference of the bamboo wall during the drying process, thereby improving the dimensional stability of the final product and reducing the cracking rate of the bamboo chip; the arc-changing bamboo chip is prepared by the equal arc length method, thereby reducing the material waste caused by different widths during the lamination process; the arc-changing bamboo chip is wider in width and has a low degree of damage to the bamboo material, thereby reducing the generation of waste and dust during the processing; the unit size of the arc-changing bamboo chip is large, which effectively improves the utilization rate of the bamboo material and reduces the amount of glue applied; the process is simple, and multi-layer gluing of the arc-changing bamboo chips can be achieved; the processing methods are diverse, and the laminated material can be processed into rectangular materials for use, or the laminated material can be sliced ​​longitudinally for use in the fields of furniture, construction, and engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Detailed description is a flow chart showing a method for processing a bamboo piece with an arc modified according to an embodiment of the present invention.

[0020] Figure 2 Schematic diagram showing a method for processing a curved bamboo piece according to an embodiment of the present invention.

[0021] Figure 3 The schematic diagram shows the arc-shaped original bamboo laminated material obtained by the arc-modified bamboo slice processing method of the present invention.

[0022] Figure 4 2 is a schematic diagram showing the preparation of curved original bamboo laminated timber by wet gluing according to an embodiment of the present invention.

[0023] Figure 5 2 is a schematic diagram showing the preparation of curved original bamboo laminated timber by dry gluing according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] Embodiments according to the present invention will be described below with reference to the accompanying drawings. In the following description of the embodiments disclosed in this specification, when the detailed description of the known functions and configurations incorporated herein may make the subject matter of the embodiments disclosed in this specification quite unclear, these descriptions will be omitted. In addition, the accompanying drawings are provided only for a better understanding of the embodiments disclosed in this specification and are not intended to limit the technical ideas disclosed in this specification. Therefore, it should be understood that the accompanying drawings include all modifications, equivalents and alternatives within the scope and spirit of the present invention.

[0025] Unless otherwise defined, all terms including technical or scientific terms have the same meaning as those generally understood by ordinary technicians in the technical field to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as consistent with the contextual meaning of the relevant technology. Unless clearly defined in the present invention, these terms should not be interpreted as ideal or overly formal meanings.

[0026] As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0027] It will be further understood that the terms “including,” “comprising,” and / or “having” used herein specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0028] In addition, the size and thickness of each configuration shown in the drawings are arbitrarily shown for understanding and ease of description, but the present invention is not limited thereto, and the thickness of layers, films, panels, regions, etc. are exaggerated for clarity.

[0029] Figure 1 Detailed description is a flow chart showing a method for processing a bamboo piece with an arc modified according to an embodiment of the present invention.

[0030] Reference Figure 1 According to an embodiment of the present invention, the arc-modified bamboo chip processing method may include the following steps: cutting a round bamboo tube and grading it according to the arc and bamboo wall thickness to obtain a graded round bamboo tube; splitting the graded round bamboo tube in a manner of equal arc length to obtain arc-shaped bamboo chips; steaming and softening the arc-shaped bamboo chips; removing the green and yellow and modifying the arc of the softened bamboo chips, using a gradually shrinking arc-shaped pressing roller to change the initial arc of the bamboo chips, so that the arc radius of the bamboo chips becomes smaller, and obtaining arc-modified bamboo chips; and placing arc-modified bamboo chips of different radius grades under different arc-shaped molds, and locking them through a locking component to cool and shape them, so as to obtain equal-arc bamboo chips of different radius grades.

[0031] Figure 2 Schematic diagram showing a method for processing a curved bamboo piece according to an embodiment of the present invention.

[0032] Reference Figure 2Specifically, the arc-modified bamboo chip processing method provided by the present invention may include the following steps: (1) selecting a round bamboo tube: selecting 3-6 year old fresh bamboo with a moisture content of about 60%; (2) cutting and grading: after cutting the round bamboo tube, the round bamboo tube is divided into three grades according to the different radii of the bamboo tube: 4-5 cm, 5-6 cm, and 6-7 cm; (3) splitting: splitting the round bamboo tube into equal arc lengths, so that the arc length of the split bamboo chips is 60-100 mm; (4) Softening: Place the split bamboo pieces into a high-pressure steam softening tank for softening; (5) Curve modification: Immediately place the softened bamboo pieces into a curve modification and planing machine to remove the green and yellow bamboo on the bamboo pieces. At the same time, use a gradually shrinking arc pressure roller to change the initial curvature of the bamboo pieces, so that the arc radius of the bamboo pieces becomes slightly smaller; (6) Cooling and shaping: Place the curved bamboo pieces of different radius grades under different arc molds, and lock them through a locking assembly for cooling and shaping, so as to obtain equal-arc bamboo pieces of different radius grades.

[0033] In the embodiment, when performing equal arc length splitting as described above, the arc length is selected to be 80 mm.

[0034] In the embodiment, when the bamboo chips are softened, the saturated steam pressure of the high-temperature steam softening tank is 1.0-1.1 MPa, and the steam treatment time is 320-440 seconds.

[0035] In the embodiment, during the arc modification process, the arc-shaped bamboo pieces with arc radii of 4-5cm, 5-6cm, and 6-7cm are modified to arc radii of 3.8cm, 4.7cm, and 5.6cm, respectively.

[0036] In the embodiment, the curved bamboo pieces are cooled and shaped, and the moisture content of the bamboo pieces is reduced to about 30%, because above the fiber saturation point, the curved bamboo pieces will not be deformed when dried.

[0037] In the embodiment, the curved bamboo piece is placed under a curved mold to be cooled and shaped for 2 hours.

[0038] According to the present invention, the removal of green and yellow and arc change are achieved by immediately placing the softened bamboo strips into an arc change and planing machine, which gradually reduces the radius of the roller to change the arc of the bamboo strips, and simultaneously removes green and yellow from the bamboo strips through arc-shaped upper and lower planers, and controls the amount of green and yellow removed from the bamboo.

[0039] According to the present invention, in the process of removing green and yellowing and changing the arc, the radius of the arc-shaped bamboo piece is reduced because the difference in the distribution of vascular bundles between the green side and the yellow side of the bamboo piece will cause the green side to have a larger shrinkage rate during drying, resulting in a larger radius of the arc-shaped bamboo piece after drying. In order to reduce the change in the initial shape of the bamboo piece, the radius of the arc-shaped bamboo piece is first reduced during the arc-changing.

[0040] According to the present invention, the arc radius is reduced rather than expanded during the arc modification process by the arc modification method, thereby offsetting the tendency of the arc radius to increase due to the radial difference of the bamboo wall during the drying process, thereby improving the dimensional stability of the final product and reducing the cracking rate of the bamboo chips.

[0041] Figure 3 The schematic diagram shows the arc-shaped original bamboo laminated material obtained by the arc-modified bamboo slice processing method of the present invention.

[0042] Reference Figure 3 The arc-shaped original bamboo laminated material is obtained by gluing the equal-arc bamboo pieces obtained by the arc-modified bamboo piece processing method provided by the present invention, and can include the following steps: (1) selecting a round bamboo tube: selecting 3-6 year-old fresh bamboo with a moisture content of about 60%; (2) cutting and grading: after cutting the round bamboo tube, the round bamboo tube is divided into three grades according to the different radii of the bamboo tube: 4-5cm, 5-6cm, and 6-7cm; (3) splitting: splitting the round bamboo tube in a manner of equal arc length, so that the arc length of the bamboo pieces obtained by splitting is 60-100mm; (4) softening the bamboo pieces: The bamboo strips are placed in a high-pressure steam softening tank for softening; (5) Curve modification: The softened bamboo strips are immediately placed in a curved planing machine to remove the green and yellow bamboo on the strips. At the same time, a gradually shrinking curved pressure roller is used to change the initial curvature of the bamboo strips, so that the arc radius of the bamboo strips becomes slightly smaller; (6) Cooling and shaping: Curved bamboo strips of different radius grades are placed under different arc molds, and locked by a locking assembly for cooling and shaping to obtain equal-arc bamboo strips of different radius grades; (7) Gluing: The equal-arc bamboo strips of different radius grades are glued to obtain curved original bamboo laminated materials.

[0043] In the embodiment, the equi-arc bamboo strips prepared by the present invention can be glued by wet method or by dry method. When the moisture content of the bamboo strips is high, wet gluing is performed.

[0044] In the embodiment, when performing equal arc length splitting as described above, the arc length is selected to be 80 mm.

[0045] In the embodiment, when the bamboo chips are softened, the saturated steam pressure of the high-temperature steam softening tank is 1.0-1.1 MPa, and the steam treatment time is 320-440 seconds.

[0046] In the embodiment, during the arc modification process, the arc-shaped bamboo pieces with arc radii of 4-5cm, 5-6cm, and 6-7cm are modified to arc radii of 3.8cm, 4.7cm, and 5.6cm, respectively.

[0047] In the embodiment, the curved bamboo pieces are cooled and shaped, and the moisture content of the bamboo pieces is reduced to about 30%, because above the fiber saturation point, the curved bamboo pieces will not be deformed when dried.

[0048] In the embodiment, the curved bamboo piece is placed under a curved mold to be cooled and shaped for 2 hours.

[0049] In the embodiment, before the wet gluing of the bamboo strips, the curved bamboo strips are cooled and shaped to a moisture content of about 30%, because above the fiber saturation point, the drying of the curved bamboo strips will not cause deformation.

[0050] In the embodiment, during the dry gluing, the equal-arc bamboo strips use arc-shaped boards as partitions during drying.

[0051] In the embodiment, during the dry gluing, the bamboo pieces are vacuum dried, which takes a short time and has high efficiency.

[0052] In the embodiment, during the above vacuum drying, the temperature is 55°C-60°C, the pressure is 90.5KPa, and the time is 24h.

[0053] In the embodiment, when the dry gluing is performed, hot pressing gluing or cold pressing gluing can be selected according to the number of bamboo sheets in the assembly. Hot pressing gluing has fast curing of the glue layer and high efficiency, and is suitable for gluing with a small number of bamboo sheets; cold pressing gluing takes a long time, but can glue more layers.

[0054] Figure 4 is a schematic diagram showing the preparation of curved original bamboo laminated timber by wet gluing according to an embodiment of the present invention, Figure 5 2 is a schematic diagram showing the preparation of curved original bamboo laminated timber by dry gluing according to an embodiment of the present invention.

[0055] According to an embodiment, the wet gluing method for preparing arc-shaped original bamboo laminated materials according to an embodiment of the present invention may include the following steps: (1) selecting round bamboo tubes: selecting 3-6 year old fresh bamboo with a moisture content of about 60%; (2) cutting and grading: after cutting the round bamboo tubes, the round bamboo tubes are divided into three grades according to the different radii of the bamboo tubes: 4-5 cm, 5-6 cm, and 6-7 cm; (3) splitting: splitting the round bamboo tubes into equal arc lengths, so that the arc length of the split bamboo pieces is 60-100 mm; (4) softening the bamboo pieces: placing the split bamboo pieces into a high pressure Soften in a steam softening tank; (5) Curve modification: immediately place the softened bamboo strips into a curved planing machine to remove the green and yellow bamboo on the bamboo strips. At the same time, use a gradually shrinking curved pressure roller to change the initial curvature of the bamboo strips, so that the arc radius of the bamboo strips becomes slightly smaller; (6) Cooling and shaping: place curved bamboo strips of different radius grades under different arc molds, and lock them through a locking assembly for cooling and shaping to obtain equal-arc bamboo strips of different radius grades; (7) Wet gluing: wet-gluing equal-arc bamboo strips of different radius grades to obtain curved original bamboo laminated materials.

[0056] Specifically, refer to Figure 4 The curved original bamboo laminated timber is prepared by wet gluing, which can be done as follows: (1) Material selection: Four-year-old fresh bamboo tube, diameter 120-130 mm, wall thickness 11-12 mm, length 120 cm, moisture content about 60%.

[0057] (2) Splitting: Split the round bamboo tube into arcs of 90 mm in length.

[0058] (3) Softening: Place the bamboo strips in a high-pressure steam softening tank for softening at a softening temperature of 180°C, a pressure of 1.0 MPa, and a time of 440 seconds.

[0059] (4) Remove green and yellow from the bamboo and change the arc: The softened bamboo strips are immediately placed in the arc-changing planing machine to remove the green and yellow from the bamboo strips until the wall thickness is 9.5 mm. The green and yellow from the bamboo strips are completely removed, and the arc radius of the bamboo strips is reduced to 5.6 cm.

[0060] (5) Cooling and shaping: Place the bamboo strips that have been curved under a curved mold for cooling and shaping, and reduce the moisture content of the bamboo strips to about 30%.

[0061] (6) Gluing: Apply adhesive on both sides of the curved bamboo strips.

[0062] (7) Wet gluing: The curved bamboo pieces are assembled in the form of bamboo green and bamboo yellow. After assembly, they are placed in a press with a curved mold for cold pressing and gluing. The prepared curved original bamboo laminated material is as follows: Figure 4 shown.

[0063] According to an embodiment, the preparation of arc-shaped original bamboo laminated materials by dry gluing according to an embodiment of the present invention may include the following steps: (1) selecting round bamboo tubes: selecting 3-6 year old fresh bamboo with a moisture content of about 60%; (2) cutting and grading: after cutting the round bamboo tubes, the round bamboo tubes are divided into three grades according to the different radii of the bamboo tubes: 4-5 cm, 5-6 cm, and 6-7 cm; (3) splitting: splitting the round bamboo tubes into equal arc lengths, so that the arc length of the split bamboo pieces is 60-100 mm; (4) softening the bamboo pieces: placing the split bamboo pieces into a high pressure Soften in a steam softening tank; (5) Curve modification: immediately place the softened bamboo strips into a curved planing machine to remove the green and yellow bamboo on the bamboo strips. At the same time, use a gradually shrinking curved pressure roller to change the initial curvature of the bamboo strips, so that the arc radius of the bamboo strips becomes slightly smaller; (6) Cooling and shaping: place curved bamboo strips of different radius grades under different arc molds, and lock them through a locking assembly for cooling and shaping to obtain equal-arc bamboo strips of different radius grades; (7) Dry gluing: dry-gluing equal-arc bamboo strips of different radius grades to obtain curved original bamboo laminated materials.

[0064] Specifically, refer to Figure 5 The curved original bamboo laminated timber is prepared by dry gluing, which can be done as follows: (1) Material selection: Four-year-old fresh bamboo tube, diameter 100-110mm, wall thickness 10-11mm, length 120cm, moisture content about 60%.

[0065] (2) Splitting: Split the round bamboo tube into arcs of 80 mm in length.

[0066] (3) Softening: Place the bamboo strips in a high-pressure steam softening tank for softening at a softening temperature of 180°C, a pressure of 1.0 MPa, and a time of 420 seconds.

[0067] (4) Remove green and yellow from the bamboo and change the arc: The softened bamboo strips are immediately placed in the arc-changing planing and cutting machine to remove the green and yellow from the bamboo strips until the wall thickness is 9.5 mm. The green and yellow from the bamboo strips are completely removed, and the arc radius of the bamboo strips is reduced to 4.7 cm.

[0068] (5) Cooling and shaping: Place the curved bamboo strips under the curved mold to cool and shape for 2 hours.

[0069] (6) Drying: The obtained modified bamboo chips are placed in a vacuum drying kiln for drying at a temperature of 55°C and a pressure of 90.5 KPa for 24 hours. The moisture content of the dried bamboo chips is about 9%.

[0070] (7) Gluing: Apply two-component polyisocyanate emulsion adhesive on both sides of the curved bamboo strips.

[0071] (8) Cold-pressed glued composite material: The curved bamboo pieces are assembled in the form of bamboo green and bamboo yellow. After the assembly, they are placed in a press with a curved mold for cold-pressing and gluing. The prepared laminated material is as follows: Figure 5 shown.

[0072] Through the above processing method, a curved original bamboo laminated material (see Figure 4 and Figure 5 ), which prepares large-width and uniform-arc bamboo strips through the method of high-temperature steam softening, removing green and yellow, and changing the arc. At the same time, it adopts two methods of wet gluing and dry gluing to achieve efficient and original utilization of bamboo.

[0073] In summary, in view of the problems of low bamboo material utilization rate, poor dimensional stability, serious damage to the original state and high amount of glue applied in the processing of existing bamboo engineering materials, the present invention proposes a method for processing arc-changing bamboo pieces, which prepares large-width equal-arc bamboo pieces by high-temperature steam softening-removing green and yellowing and arc-changing. At the same time, a kind of arc-shaped original bamboo laminate prepared by the arc-changing bamboo piece processing method of the present invention is proposed, and the arc-shaped original bamboo laminate is prepared by two methods of wet gluing and dry gluing, so as to realize the efficient utilization and original state utilization of bamboo. The arc-changing bamboo piece processing method of the present invention can greatly improve the material utilization rate, improve the dimensional stability of the product, reduce the amount of glue applied, and can realize the multi-layer gluing of arc-shaped bamboo pieces, which greatly broadens the application range of bamboo materials and provides a new way for the preparation of bamboo engineering materials.

[0074] Although the present teaching has been described with respect to specific embodiments, it is obvious to those skilled in the art that, according to the present disclosure, various changes and modifications may be made without departing from the spirit and scope of the present disclosure as defined in the appended claims. In addition, the embodiments may be combined to form other embodiments.

Claims

1. A method for processing curved bamboo pieces, characterized in that: The following steps are involved: Cut the round bamboo tube and grade it according to the curvature and bamboo wall thickness to obtain graded round bamboo tubes; The graded round bamboo tube is split into equal arc lengths to obtain arc-shaped bamboo pieces; Steam and soften the curved bamboo pieces; The softened bamboo pieces are subjected to de-greening and de-yellowing and arc-changing treatments, and the initial arc of the bamboo pieces is changed by using gradually shrinking arc-shaped pressing rollers, so that the arc radius of the bamboo pieces becomes smaller, thereby obtaining arc-changed bamboo pieces; as well as The arc-modified bamboo pieces with different radius levels are placed under different arc-shaped molds, and are locked by a locking component to be cooled and shaped, so as to obtain equal-arc bamboo pieces with different radius levels.

2. The method for processing curved bamboo pieces according to claim 1, characterized in that: The round bamboo tubes are selected from 3-6 year old fresh bamboo tubes with a moisture content of about 60%. After the round bamboo tubes are cut, they are divided into three grades according to their different radii: 4-5cm, 5-6cm, and 6-7cm.

3. The method for processing curved bamboo pieces according to claim 1, characterized in that: When performing equal arc length splitting, the arc length ranges from 50 to 100 mm, and the length of the arc-shaped bamboo pieces is from 60 to 240 cm.

4. The method for processing curved bamboo pieces according to claim 1, characterized in that: When the bamboo chips are softened, the steam pressure is 1.0~1.1Mpa, and the saturated steam treatment time is 320~440s.

5. The arc-changing bamboo strip processing method according to claim 2, characterized in that: The green and yellow removal and arc modification of the bamboo strips are performed in sequence. The arc-shaped bamboo strips after the green and yellow removal are passed through gradually shrinking arc-shaped pressing rollers to change the initial arc radius of the bamboo strips, so that the initial arc radius of the bamboo strips becomes smaller.

6. The method for processing curved bamboo pieces according to claim 5, characterized in that: The arc-shaped bamboo pieces with arc radii of 4-5cm, 5-6cm, and 6-7cm are changed to arc radii of 3.8cm, 4.7cm, and 5.6cm respectively.

7. The method for processing curved bamboo pieces according to claim 1, characterized in that: The curved bamboo strips are cooled and shaped, and the moisture content of the bamboo strips is reduced to about 30%.

8. The method for processing curved bamboo pieces according to claim 1, characterized in that: Place the curved bamboo piece under the curved mold to cool and shape for 2 hours.

9. An arc-shaped original bamboo laminated timber, characterized in that: The arc-shaped original bamboo laminate is obtained by gluing the arc-modified bamboo pieces obtained by the arc-modified bamboo piece processing method according to any one of claims 1 to 8.

10. The curved original bamboo laminated timber according to claim 9, characterized in that: When the moisture content of the curved bamboo strips is high, wet gluing is performed, or dry gluing is performed after the curved bamboo strips are dried.

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