Arc-shaped raw bamboo laminated wood and arc-shaped bamboo sheet processing method

Abstract

The present application relates to a kind of arc bamboo sheet processing method and arc original state bamboo laminated wood.The arc bamboo sheet processing method includes the following steps: cutting off round bamboo cylinder, grading according to arc and bamboo wall thickness, obtain graded round bamboo cylinder;Arc-shaped bamboo sheet is obtained by splitting graded round bamboo cylinder in equal arc length;Arc-shaped bamboo sheet is treated by steam and softening;After softening, the arc of bamboo sheet is changed by using gradually reduced arc-shaped pressure roller, so that the arc radius of bamboo sheet is smaller, and arc bamboo sheet is obtained;And different radius levels of arc bamboo sheet are placed under different arc-shaped mould, and cooling is fixed by locking assembly locking, and different radius levels of equal arc bamboo sheet are obtained.By the above method, an arc-shaped original state bamboo laminated wood is obtained.The arc-shaped original state bamboo laminated wood processed by the method of the present application improves the dimensional stability of the final product and reduces the cracking rate of bamboo sheet.

Description

Technical Field

[0001] This invention belongs to the field of materials processing, specifically relating to a method for processing curved bamboo strips and curved original bamboo laminated timber. Background Technology

[0002] Bamboo has a short growth cycle, strong carbon sequestration capacity, and excellent mechanical properties, making it a sustainable agricultural resource often used in the production of bamboo-based engineering materials. However, due to bamboo's natural ring structure, it cannot be directly processed into boards or squares. It needs to be processed into various bamboo units, such as standard bamboo strips, bamboo filaments, bamboo shavings, etc., which are then glued together after gluing and assembly. This process causes significant damage to the raw material, results in low material utilization, and leads to high glue usage. To reduce damage to bamboo, improve material utilization, and lower glue usage, bamboo flattening technology has been developed and applied.

[0003] However, bamboo flattening technology requires high-precision equipment and specialized operating skills, and it is difficult to ensure that the bamboo does not crack or deform during the flattening process. Furthermore, the bamboo flattening equipment currently on the market is diverse in type and performance, and its operation is complex, requiring highly skilled workers. 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, its practical application is still limited. On the one hand, due to the inherent growth characteristics and structural features of bamboo, cracking and deformation are prone to occur during the flattening process, thus affecting the yield and utilization rate of the bamboo. On the other hand, different types of bamboo perform differently during the flattening process; some bamboos are difficult to flatten to the ideal effect, which also limits the utilization rate. Bamboo flattening technology has high energy consumption during processing, which also has a certain negative impact on the environment. Moreover, the flattening process significantly alters the shape of the bamboo strips, resulting in high residual stress within the bamboo strips, leading to poor dimensional stability, warping, and frequent cracking during the drying process.

[0004] To improve the utilization rate of bamboo without damaging its original state, CN 1970254A proposes a method for the original arc-shaped reassembly of bamboo. This method involves milling split, arc-shaped bamboo strips to make the inner and outer arc radii equal or similar, and then gluing the bamboo strips together with the green side facing the yellow side. This method preserves the natural gradient structure, arc-shaped characteristics, and biomechanical strength of bamboo. However, some problems remain: after milling the original bamboo strips into equal-arc strips, the yield increase is limited, and the strip width is relatively small (2-3 cm). The resulting laminated timber has a small width, thus limiting its applications. Furthermore, the original arc-shaped gluing of bamboo strips is more complex than traditional straight bamboo strip processing techniques. This is mainly reflected in the need for precise control of parameters such as milling arc and gluing pressure during the arc milling and gluing processes to ensure product quality. This increases the technical difficulty and quality control requirements of the production process. Because the curved bamboo strip gluing technique requires specialized equipment and processes, such as curved milling machines and precision gluing equipment, the purchase and maintenance costs of this equipment are relatively high. At the same time, due to the complexity of the process, labor and time costs during production also increase accordingly, resulting in a higher overall production cost. Summary of the Invention

[0005] This invention addresses the problems of low bamboo utilization, poor dimensional stability, severe damage to the original state, and high glue application rates in existing bamboo engineering material processing. It proposes a method to prepare wide, uniformly curved bamboo strips through high-temperature steam softening, de-greening and de-yellowing, and arc modification. Simultaneously, it employs both wet and dry gluing methods to prepare curved, original-state bamboo laminated lumber, thereby achieving efficient and original-state bamboo utilization. This method significantly improves material utilization, enhances product dimensional stability, reduces glue application, and enables multi-layer gluing of curved bamboo strips, greatly expanding the application range of bamboo and providing a new approach for the preparation of bamboo engineering materials.

[0006] According to one aspect of the present invention, a method for processing modified bamboo strips is provided, which may include the following steps:

[0007] - Cut the round bamboo tubes and grade them according to their curvature and bamboo wall thickness to obtain graded round bamboo tubes;

[0008] - The graded round bamboo tubes are split into arc-shaped bamboo strips by using equal arc lengths;

[0009] - The curved bamboo strips are steamed and softened.

[0010] - The softened bamboo strips undergo a process of removing the green and yellow pigments and reshaping the arc. Gradually decreasing arc-shaped pressure rollers are used to alter the initial curvature of the bamboo strips, reducing the radius of the arc and resulting in reshaped bamboo strips; and

[0011] - Bamboo strips of different radius grades are placed under different arc molds and locked by locking components for cooling and shaping to obtain equal arc bamboo strips of different radius grades.

[0012] According to an embodiment of the present invention, the round bamboo tube can be selected from fresh bamboo tubes that are 3-6 years old, 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.

[0013] According to an embodiment of the present invention, when performing equal arc length segmentation, the arc length range can be 50-100mm, and the length of the arc-shaped bamboo strip is 60-240cm.

[0014] According to an embodiment of the present invention, when performing bamboo softening treatment, the steam pressure can be 1.0~1.1 MPa, and the saturated steam treatment time can be 320~440 s.

[0015] According to an embodiment of the present invention, the removal of green and yellow from bamboo strips and the modification of the arc shape can be carried out sequentially. After the removal of green and yellow, the initial arc radius of the bamboo strip can be changed by gradually shrinking arc-shaped pressure rollers, so that the initial arc radius of the bamboo strip becomes smaller.

[0016] According to an embodiment of the present invention, the curved bamboo strips with arc radii of 4-5cm, 5-6cm, and 6-7cm can be modified to have arc radii of 3.8cm, 4.7cm, and 5.6cm, respectively.

[0017] According to an embodiment of the present invention, the modified bamboo strips can be cooled and shaped, and the moisture content of the bamboo strips can be reduced to about 30%.

[0018] According to an embodiment of the present invention, the modified bamboo strip can be placed under an arc-shaped mold for cooling and shaping for 2 hours.

[0019] According to one aspect of the present invention, an arc-shaped original bamboo laminated material is provided, which can be obtained by gluing together equal-arc bamboo strips obtained by the modified arc bamboo strip processing method according to the present invention.

[0020] According to embodiments of the present invention, the uniformly curved bamboo strips obtained by the modified bamboo strip processing method described herein can be wet-glued when the bamboo strips have a high moisture content, or they can be dry-glued after drying. Both gluing methods can produce curved original bamboo laminated lumber.

[0021] Furthermore, wet bonding includes: applying adhesive to modified bamboo strips with a moisture content around the fiber saturation point in the form of bamboo green and bamboo yellow, and then placing the assembled strips into a press with an arc-shaped mold for cold pressing and bonding.

[0022] Furthermore, the dry bonding process includes: placing the modified bamboo strips, after being shaped for 2 hours, into a drying kiln for drying, reducing the moisture content of the bamboo strips to about 10%, and then applying adhesive to form a blank in the form of bamboo green and bamboo yellow. After the blank is formed, it is placed into a press with an arc-shaped mold for bonding.

[0023] According to embodiments of the present invention, the arc-shaped original state bamboo laminated lumber prepared by the arc-modified bamboo strip processing method of the present invention retains the original gradient structure and mechanical strength of the bamboo. The arc-modified bamboo strip processing method of the present invention, by reducing the arc radius during the arc-modification process rather than expanding it, offsets the tendency for the arc radius to increase due to radial differences in the bamboo wall during drying, thereby improving the dimensional stability of the final product and reducing the cracking rate of the bamboo strips. Using a method of equal arc length to prepare the arc-modified bamboo strips reduces material waste caused by inconsistent widths during lamination. The wider arc-modified bamboo strips cause less damage to the bamboo, thus reducing waste and dust generation during processing. The large unit size of the arc-modified bamboo strips effectively improves the utilization rate of the bamboo and reduces the amount of adhesive applied. The process is simple and allows for multi-layer gluing of the arc-modified bamboo strips. The processing methods are diverse; the laminated lumber can be processed into rectangular pieces for use, or longitudinally sliced ​​for applications in furniture, construction, and engineering. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating a modified bamboo strip processing method according to an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram illustrating a modified bamboo strip processing method according to an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram showing the arc-shaped original bamboo laminated timber obtained by the modified bamboo strip processing method of the present invention.

[0027] Figure 4 This is a schematic diagram illustrating the wet bonding preparation of arc-shaped original bamboo laminated lumber according to an embodiment of the present invention.

[0028] Figure 5 This is a schematic diagram illustrating the preparation of arc-shaped original bamboo laminated lumber by dry gluing according to an embodiment of the present invention. Detailed Implementation

[0029] The embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description of the embodiments disclosed herein, detailed descriptions of known functions and configurations incorporated herein may render the subject matter of the disclosed embodiments quite unclear, such descriptions will be omitted. Furthermore, the accompanying drawings are provided only for a better understanding of the embodiments disclosed herein and are not intended to limit the technical ideas disclosed herein. Therefore, it should be understood that the drawings include all modifications, equivalents, and alternatives within the scope and spirit of the invention.

[0030] Unless otherwise defined, all terms, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms such as those defined in commonly used dictionaries shall be interpreted as consistent with their meaning in the context of the relevant art. Unless expressly defined in this invention, these terms shall not be construed as having an ideal or overly formal meaning.

[0031] As used in this article, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0032] It will be further understood that the terms “comprising,” “including,” and / or “having” as used herein specify the presence of the stated features, integers, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0033] In addition, for the sake of understanding and ease of description, the dimensions and thicknesses of the various structures shown in the accompanying drawings are arbitrarily shown, but the invention is not limited thereto, and for clarity, the thicknesses of layers, films, plates, regions, etc., are exaggerated.

[0034] Figure 1 This is a flowchart illustrating a modified bamboo strip processing method according to an embodiment of the present invention.

[0035] Reference Figure 1 The method for processing curved bamboo strips according to an embodiment of the present invention may include the following steps: cutting a round bamboo tube and grading it according to its curvature and bamboo wall thickness to obtain graded round bamboo tubes; splitting the graded round bamboo tubes into equal arc lengths to obtain curved bamboo strips; subjecting the curved bamboo strips to steam and softening treatment; subjecting the softened bamboo strips to de-greening, de-yellowing, and curvature-modifying treatment, using progressively smaller curved pressure rollers to change the initial curvature of the bamboo strips, thereby reducing the arc radius of the bamboo strips to obtain curved bamboo strips; and placing curved bamboo strips of different radius grades under different curved molds and locking them with locking components for cooling and shaping to obtain equal arc bamboo strips of different radius grades.

[0036] Figure 2 This is a schematic diagram illustrating a modified bamboo strip processing method according to an embodiment of the present invention.

[0037] Reference Figure 2 Specifically, the modified bamboo strip processing method provided by the present invention may include the following steps: (1) Selecting round bamboo tubes: Selecting fresh bamboo of 3-6 years old 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: 4-5cm, 5-6cm, and 6-7cm; (3) Splitting: Splitting the round bamboo tubes in a manner with equal arc lengths, so that the arc length of the bamboo strips obtained from the splitting is 60-100mm; (4) Bamboo strips Softening: The split 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 curve modification planing machine to remove the bamboo green and yellow on the bamboo strips. At the same time, the initial curvature of the bamboo strips is changed by using gradually shrinking arc pressure rollers to make the arc radius of the bamboo strips slightly smaller; (6) Cooling and shaping: The curved bamboo strips of different radius grades are placed under different arc molds and locked by locking components for cooling and shaping to obtain equal-arc bamboo strips of different radius grades.

[0038] In the embodiment, when performing equal arc length subdivision, an arc length of 80mm is selected.

[0039] In the embodiment, when softening bamboo strips as described above, 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 s.

[0040] In the embodiment, during the modification process, the curved bamboo strips with arc radii of 4-5cm, 5-6cm, and 6-7cm were modified to have arc radii of 3.8cm, 4.7cm, and 5.6cm, respectively.

[0041] In this embodiment, the modified bamboo strips are cooled and shaped, and the moisture content of the bamboo strips is reduced to about 30%, because the drying of the modified bamboo strips will not cause deformation when the fiber saturation point is above the saturation point.

[0042] In this embodiment, the modified bamboo strips were placed under an arc-shaped mold for cooling and shaping for 2 hours.

[0043] According to the present invention, the removal of green and yellow and the modification of the arc are achieved by immediately placing the softened bamboo strips into an integrated arc modification and planing machine. The integrated arc modification and planing machine realizes the modification of the bamboo strips by gradually reducing the radius of the rollers, and at the same time realizes the removal of green and yellow from the bamboo strips by using the upper and lower arc-shaped planing blades, and controls the amount of bamboo green and yellow removed.

[0044] According to the present invention, the removal of green and yellow hues and the modification of the arc shape are carried out by reducing the radius of the arc-shaped bamboo strips because the inherent difference in the distribution of vascular bundles on the green and yellow sides of the bamboo strips leads to a larger shrinkage rate on the green side during drying, resulting in a larger radius of the modified arc bamboo strips after drying. In order to reduce the change in the initial shape of the bamboo strips, the radius of the arc-shaped bamboo strips is reduced first during the modification of the arc shape.

[0045] According to the present invention, the above-described method for processing curved bamboo strips reduces the radius of curvature during the curvature process, rather than expanding it, thereby offsetting the tendency for the radius of curvature to increase due to radial differences in the bamboo wall during the drying process. This improves the dimensional stability of the final product and reduces the cracking rate of the bamboo strips.

[0046] Figure 3 This is a schematic diagram showing the arc-shaped original bamboo laminated timber obtained by the modified bamboo strip processing method of the present invention.

[0047] Reference Figure 3 The arc-shaped original bamboo laminated material is obtained by gluing the equal arc bamboo strips prepared by the modified arc bamboo strip processing method provided by the present invention, which may include the following steps: (1) Selecting round bamboo tubes: Selecting fresh moso bamboo aged 3-6 years 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: 4-5cm, 5-6cm, and 6-7cm; (3) Splitting: Splitting the round bamboo tubes in the manner of equal arc length, so that the arc length of the bamboo strips obtained by splitting is 60-100mm; (4) Softening the bamboo strips: softening the bamboo strips by splitting the bamboo strips. (5) Curving: The softened bamboo strips are immediately placed in a curved planer to remove the green and yellow bamboo on the bamboo strips. At the same time, the initial curvature of the bamboo strips is changed by using gradually shrinking curved pressure rollers to make the curvature radius of the bamboo strips slightly smaller. (6) Cooling and shaping: Curved bamboo strips of different radius grades are placed under different curved molds and locked by locking components to cool and shape them, so as to obtain equal-curvature bamboo strips of different radius grades. (7) Gluing: Equal-curvature bamboo strips of different radius grades are glued together to obtain curved original state bamboo laminated material.

[0048] In the embodiments, the uniformly curved bamboo strips obtained by the present invention can be subjected to either wet gluing or dry gluing. Wet gluing is performed when the bamboo strips have a high moisture content.

[0049] In the embodiment, when performing equal arc length subdivision, an arc length of 80mm is selected.

[0050] In the embodiment, when softening bamboo strips as described above, 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 s.

[0051] In the embodiment, during the modification process, the curved bamboo strips with arc radii of 4-5cm, 5-6cm, and 6-7cm were modified to have arc radii of 3.8cm, 4.7cm, and 5.6cm, respectively.

[0052] In this embodiment, the modified bamboo strips are cooled and shaped, and the moisture content of the bamboo strips is reduced to about 30%, because the drying of the modified bamboo strips will not cause deformation when the fiber saturation point is above the saturation point.

[0053] In this embodiment, the modified bamboo strips were placed under an arc-shaped mold for cooling and shaping for 2 hours.

[0054] In the embodiment, before the bamboo strips are wet-bonded, the modified bamboo strips are cooled and shaped to a moisture content of about 30%, because the drying of the modified bamboo strips will not cause deformation when the fiber saturation point is above the saturation point.

[0055] In the embodiments, during the dry bonding process described above, the curved bamboo strips are dried using an arc-shaped plate as a partition.

[0056] In the embodiments, when performing the above-mentioned dry bonding, the bamboo strips are vacuum dried, which is faster and more efficient.

[0057] In the embodiment, the vacuum drying process was carried out at a temperature of 55°C-60°C, a pressure of 90.5 kPa, and a time of 24 hours.

[0058] In the embodiments, during the above-mentioned dry bonding process, hot-press bonding or cold-press bonding can be selected according to the number of bamboo strip layers in the assembly. Hot-press bonding results in rapid curing of the adhesive layer and high efficiency, making it suitable for bonding assemblies with a small number of layers; cold-press bonding takes longer but can bond more layers.

[0059] Figure 4 This is a schematic diagram illustrating the wet bonding preparation of arc-shaped original bamboo laminated lumber according to an embodiment of the present invention. Figure 5 This is a schematic diagram illustrating the preparation of arc-shaped original bamboo laminated lumber by dry gluing according to an embodiment of the present invention.

[0060] According to the embodiments, the preparation of arc-shaped original bamboo laminated material by wet gluing according to the embodiments of the present invention may include the following steps: (1) Selecting round bamboo tubes: Selecting fresh moso bamboo aged 3-6 years 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: 4-5cm, 5-6cm, and 6-7cm; (3) Splitting: Splitting the round bamboo tubes in a manner with equal arc lengths, so that the arc length of the bamboo strips obtained from the splitting is 60-100mm; (4) Softening the bamboo strips: Putting the split bamboo strips into a high pressure. (5) Curving: The softened bamboo strips are immediately placed into the curved planer to remove the bamboo green and yellow on the bamboo strips. At the same time, the initial curvature of the bamboo strips is changed by using gradually shrinking arc-shaped pressure rollers to make the arc radius of the bamboo strips slightly smaller. (6) Cooling and shaping: The curved bamboo strips of different radius grades are placed under different arc molds and locked by locking components to cool and shape them, so as to obtain equal-arc bamboo strips of different radius grades. (7) Wet gluing: The equal-arc bamboo strips of different radius grades are wet-glued to obtain arc-shaped original bamboo laminated wood.

[0061] Specifically, refer to Figure 4 The curved, unrefined bamboo laminated timber is prepared by wet gluing and can be processed as follows:

[0062] (1) Material selection: Four-year-old fresh bamboo tubes, with a diameter of 120-130mm, a wall thickness of 11-12mm, a length of 120cm, and a moisture content of about 60%.

[0063] (2) Splitting: Split the round bamboo tube into sections with an arc length of 90mm.

[0064] (3) Softening: The bamboo strips are placed in a high-pressure steam softening tank for softening. The softening temperature is 180℃, the pressure is 1.0Mpa, and the time is 440s.

[0065] (4) Remove green and yellow and modify the arc: Immediately put the softened bamboo strips into the arc-modification planing machine. After removing the green and yellow from the bamboo strips, the wall thickness is 9.5mm. The green and yellow of the bamboo strips are completely removed, and the arc radius of the bamboo strips is reduced to 5.6cm.

[0066] (5) Cooling and shaping: Place the bamboo strips after the arc is modified under the arc mold for cooling and shaping, and reduce the moisture content of the bamboo strips to about 30%.

[0067] (6) Apply adhesive: Apply adhesive to both sides of the modified bamboo strip.

[0068] (7) Wet gluing: The modified bamboo strips are assembled in the form of bamboo green and bamboo yellow. After assembly, they are placed in a press with an arc-shaped mold for cold pressing and gluing. The prepared arc-shaped original bamboo laminated timber is as follows: Figure 4 As shown.

[0069] According to the embodiments, the preparation of arc-shaped original bamboo laminated material by dry gluing according to the embodiments of the present invention may include the following steps: (1) Selecting round bamboo tubes: Selecting fresh moso bamboo aged 3-6 years 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: 4-5cm, 5-6cm, and 6-7cm; (3) Splitting: Splitting the round bamboo tubes in a manner with equal arc lengths, so that the arc length of the bamboo strips obtained from the splitting is 60-100mm; (4) Softening the bamboo strips: Putting the split bamboo strips into a high pressure. (5) Curving: The softened bamboo strips are immediately placed into the curved planer to remove the green and yellow bamboo strips. At the same time, the initial curvature of the bamboo strips is changed by using gradually shrinking arc-shaped pressure rollers to make the arc radius of the bamboo strips slightly smaller. (6) Cooling and shaping: The curved bamboo strips of different radius grades are placed under different arc molds and locked by locking components to cool and shape them, so as to obtain equal-arc bamboo strips of different radius grades. (7) Dry gluing: The equal-arc bamboo strips of different radius grades are dry-glued to obtain arc-shaped original bamboo laminated wood.

[0070] Specifically, refer to Figure 5 The curved, unvarnished bamboo laminated timber is prepared by dry gluing and can be processed as follows:

[0071] (1) Material selection: Four-year-old fresh bamboo tubes, with a diameter of 100-110mm, a wall thickness of 10-11mm, a length of 120cm, and a moisture content of about 60%.

[0072] (2) Splitting: Split the round bamboo tube into sections with an arc length of 80mm.

[0073] (3) Softening: The bamboo strips are placed in a high-pressure steam softening tank for softening. The softening temperature is 180℃, the pressure is 1.0Mpa, and the time is 420s.

[0074] (4) Remove green and yellow and modify the arc: Immediately put the softened bamboo strips into the arc-modification and slicing machine. After removing the green and yellow from the bamboo strips, the wall thickness is 9.5mm. The green and yellow of the bamboo strips are completely removed, and the arc radius of the bamboo strips is reduced to 4.7cm.

[0075] (5) Cooling and shaping: Place the bamboo strips after the arc is modified under the arc mold for cooling and shaping for 2 hours.

[0076] (6) Drying: The obtained modified bamboo strips are placed in a vacuum drying kiln for drying at a temperature of 55℃, a pressure of 90.5KPa, and a time of 24h. The moisture content of the dried bamboo strips is about 9%.

[0077] (7) Apply adhesive: Apply a two-component polyisocyanate emulsion adhesive to both sides of the modified bamboo strip.

[0078] (8) Cold-pressed laminated timber: Modified bamboo strips are assembled in the form of bamboo green and bamboo yellow, and after assembly, they are placed in a press with an arc-shaped mold for cold pressing and gluing. The resulting laminated timber is as follows: Figure 5 As shown.

[0079] Through the above processing method, an arc-shaped original bamboo laminated timber is obtained (see...). Figure 4 and Figure 5 It prepares wide, uniformly curved bamboo strips through a high-temperature steam softening-removal of green and yellowing and arc modification method. At the same time, it uses two methods, wet gluing and dry gluing, to achieve efficient and original utilization of bamboo materials.

[0080] In summary, addressing the problems of low bamboo utilization, poor dimensional stability, severe damage to the original state, and high glue application rates in existing bamboo engineering material processing, this invention proposes a method for processing curved bamboo strips. This method uses high-temperature steam softening and de-yellowing to prepare wide, uniformly curved bamboo strips. Furthermore, it proposes a method for preparing curved, original-state bamboo laminated lumber using this method, employing both wet and dry gluing techniques. This achieves efficient and original-state bamboo utilization. The curved bamboo strip processing method of this invention significantly improves material utilization, enhances product dimensional stability, reduces glue application, and enables multi-layer gluing of curved bamboo strips, greatly expanding the application range of bamboo and providing a new approach for the preparation of bamboo engineering materials.

[0081] While this teaching has been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made to this disclosure without departing from the spirit and scope of the disclosure as defined by the appended claims. Furthermore, embodiments may be combined to form other embodiments.

Claims

1. A method for processing modified bamboo strips, characterized in that, Includes the following steps: The round bamboo tubes are cut and graded according to their curvature and wall thickness to obtain graded round bamboo tubes. Based on the different radii of the round bamboo tubes, they are divided into three grades: 4-5cm, 5-6cm, and 6-7cm. Graded round bamboo tubes are split into arc-shaped bamboo strips by using equal arc lengths. The curved bamboo strips are steamed and softened. The softened bamboo strips are then treated to remove the green and yellow hues and to modify their curvature. An arc-shaped pressure roller with a gradually decreasing arc radius is used to change the initial curvature of the bamboo strips, thereby reducing the arc radius. Bamboo strips 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, to obtain modified curvature bamboo strips. Different radius grades of modified bamboo strips are placed under different curved molds and locked by locking components for cooling and shaping to obtain equal-arc bamboo strips of different radius grades.

2. The method for processing modified bamboo strips according to claim 1, characterized in that, The round bamboo tubes are made from fresh bamboo tubes that are 3-6 years old.

3. The method for processing modified bamboo strips according to claim 1, characterized in that, When performing equal arc length segmentation, the arc length range is 50-100mm, and the length of the arc-shaped bamboo strip is 60-240cm.

4. The method for processing modified bamboo strips according to claim 1, characterized in that, When softening bamboo strips, the steam pressure is 1.0~1.1 MPa and the saturated steam treatment time is 320~440 s.

5. The method for processing modified bamboo strips according to claim 2, characterized in that, The process of removing the green and yellow parts of the bamboo strips and reshaping the arc is carried out sequentially. After removing the green and yellow parts, the initial arc radius of the bamboo strips is changed by the arc-shaped pressure rollers that gradually reduce the arc radius, thus making the initial arc radius of the bamboo strips smaller.

6. The method for processing modified bamboo strips according to claim 1, characterized in that, The modified bamboo strips were placed under an arc-shaped mold and cooled and shaped for 2 hours.

7. An arc-shaped, original state bamboo laminated timber, characterized in that, The arc-shaped original bamboo laminated material is obtained by gluing together the modified bamboo strips obtained by the modified bamboo strip processing method according to any one of claims 1 to 6.

Images