Bamboo-fiber-wound composite pipe and manufacturing method therefor

Abstract

The present invention relates to the technical field of bamboo-fiber-wound composite pipes. Disclosed are a bamboo-fiber-wound composite pipe and a manufacturing method therefor. The composite pipe comprises a rigid inner sleeve, a bamboo-fiber winding layer and a rigid outer sleeve in sequence from inside to outside, wherein a plurality of bumps are arranged in an annular array on the outer side wall of the rigid inner sleeve, the lengthwise directions of the bumps are consistent with the axial direction of the rigid inner sleeve, the bumps protrude outwards in the radial direction of the rigid inner sleeve, and the bumps are spaced apart from each other; resin is filled between every two adjacent bumps; the bamboo-fiber winding layer is wound around the bumps; and a plurality of V-shaped grooves are arranged in an annular array on the inner side wall of the rigid outer sleeve, and the lengthwise directions of the V-shaped grooves are consistent with the axial direction of the rigid outer sleeve. The composite pipe combines the natural corrosion resistance of bamboo fibers and the chemical stability of the resin, and has an excellent mechanical strength and environmental aging resistance, thereby being suitable for long-term use in various severe environments.

Description

Bamboo fiber wound composite pipe and manufacturing method thereof Technical Field

[0001] The present invention relates to the technical field of bamboo fiber wound composite pipes, specifically a bamboo fiber wound composite pipe and a manufacturing method thereof. The composite pipe combines the natural corrosion resistance of bamboo fiber and the chemical stability of resin, has excellent mechanical strength and resistance to environmental aging, and is suitable for long-term use in various harsh environments. Background Art

[0002] With the acceleration of urbanization and the continuous advancement of infrastructure construction, pipelines, as a vital transportation medium, play an irreplaceable role in various fields, including construction, agriculture, and industry. However, traditional pipe materials such as steel pipes, plastic pipes, and cement pipes have gradually exposed numerous drawbacks during use. Although steel pipes have high mechanical strength, they have poor corrosion resistance, are prone to rust, and their production consumes a lot of energy, causing certain environmental pollution. While plastic pipes are corrosion-resistant, they have relatively low mechanical strength, are prone to aging, and have a limited service life. Cement pipes are heavy, difficult to install, and have poor environmental adaptability.

[0003] To address these issues, researchers are exploring the use of new composite materials for pipe manufacturing. Composite materials, with their exceptional properties such as light weight, high strength, and corrosion resistance, have become a research hotspot in the pipe industry. Bamboo fiber, a naturally high-strength, corrosion-resistant material, boasts renewable resources, a short growth cycle, and low cost, making it a highly sought-after reinforcement material in composite materials.

[0004] However, effectively combining bamboo fiber with resin to create a composite pipe with high strength and stability is not easy. First, the smooth surface of bamboo fiber makes it weakly bonded to the resin, which can easily lead to delamination between the layers. Second, bamboo fiber has a high water absorption rate, which can easily lead to performance degradation in humid environments. Finally, the composite pipe production process requires resolving a series of technical challenges, including winding technology, curing molding, and quality control.

[0005] Although some research has attempted to use bamboo fiber to make composite pipes, most have suffered from unstable performance, complex production processes, and high costs, making large-scale industrial production difficult. Therefore, developing a bamboo fiber-wound composite pipe with excellent performance, simple production processes, and reasonable costs, and its production method, has important practical significance and broad application prospects. Summary of the Invention

[0006] This invention provides a bamboo fiber-wound composite pipe and its manufacturing method. By providing an annular array of bumps on the outside of the inner tube, filling the spaces between the bumps with resin, and then wrapping the bamboo fiber layer, the overall mechanical strength of the pipe is significantly enhanced. Furthermore, the V-grooved design on the inside of the rigid outer tube not only increases the pipe's compressive strength but also effectively prevents slippage of the bamboo fiber layer, improving structural stability.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: a bamboo fiber wound composite tube, which comprises, from the inside to the outside, a hard inner tube, a bamboo fiber wound layer and a hard outer tube;

[0008] A plurality of protrusions are arranged in an annular array on the outer wall of the hard inner tube, wherein the length direction of the protrusions is consistent with the axial direction of the hard inner tube, and the protrusions protrude outward along the radial direction of the hard inner tube. The protrusions are arranged at intervals, and resin is filled between adjacent protrusions. The bamboo fiber winding layer is wound around each of the protrusions.

[0009] A plurality of V-shaped grooves are arranged in a circular array on the inner side wall of the hard outer cylinder, and the length direction of the V-shaped grooves is consistent with the axial direction of the hard outer cylinder.

[0010] A method for manufacturing a bamboo fiber wound composite pipe comprises the following steps:

[0011] a. Prepare a hard inner cylinder and arrange multiple protrusions on its outer wall in a circular array to ensure that the length direction of the protrusions is consistent with the axial direction of the hard inner cylinder, and the protrusions are radially outward along the hard inner cylinder, and the protrusions are spaced apart;

[0012] b. Uncured resin is injected between adjacent bumps. With the help of the surface tension of the resin, the uncured resin protrudes above the two bumps but does not overflow, so that the liquid surface of the resin is arched and maintains this shape until the resin solidifies;

[0013] c. After the resin solidifies, polish the arched surface of the resin block to ensure that the protruding portion of the resin matches the V-groove shape on the inner wall of the hard outer cylinder to be installed later, to ensure good structural stability and corrosion resistance;

[0014] d. Tightly wrap the bamboo fiber layer around the polished resin block and bumps, utilizing the high strength and corrosion resistance of bamboo to enhance the mechanical properties and environmental aging resistance of the composite pipe;

[0015] e. Prepare a hard outer cylinder and open multiple V-shaped grooves on its inner wall in a circular array, ensuring that the length direction of the V-shaped grooves is consistent with the axial direction of the hard outer cylinder;

[0016] f. The inner tube structure wrapped with a bamboo fiber layer is inserted into the hard outer tube, so that the outer surface of the bamboo fiber layer is in close contact with the V-groove inside the hard outer tube to form a stable composite structure;

[0017] g. Carry out necessary sorting and inspection on the composite pipe to ensure that it meets the predetermined quality and performance requirements.

[0018] In some embodiments, in step c, when processing the resin block with an arched surface, a rough cut is first performed to remove excess resin, followed by a fine grinding process.

[0019] In some embodiments, in step d, when winding the bamboo fiber layer, a device for remotely detecting tension and angle is used to monitor in real time and ensure that the bamboo fiber layer is tightly and evenly wound with appropriate tension and angle.

[0020] In some embodiments, in step b, when injecting uncured resin between adjacent bumps, first ensure that the gaps between the bumps are uniform and clean without impurities, and then use precise metering equipment to slowly and evenly inject the uncured resin into the gaps.

[0021] In some embodiments, in step f, when inserting the inner cylinder structure wrapped with the bamboo fiber layer into the hard outer cylinder, a laser positioning device is used to ensure precise alignment between the inner cylinder structure and the hard outer cylinder.

[0022] In some embodiments, in step g, when the composite pipe is subjected to necessary sorting and inspection, non-destructive testing technology is used to conduct a comprehensive inspection of the overall structure and internal quality of the composite pipe.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention employs a unique structural design that significantly enhances the pipe's overall mechanical strength by placing an annular array of bumps on the outside of the inner tube, filling the spaces between the bumps with resin, and then wrapping the bamboo fiber layers around them. The natural high strength of the bamboo fiber combined with the chemical stability of the resin results in a composite pipe that exhibits superior compressive and flexural resistance when subjected to external forces.

[0025] Bamboo fiber itself has natural corrosion resistance. By combining bamboo fiber with resin, the present invention forms a dense anti-corrosion layer on both the inner and outer surfaces of the composite pipe. This anti-corrosion layer effectively resists erosion by various corrosive media, allowing the composite pipe to remain corrosion-free for long periods of use even in harsh environments.

[0026] The V-grooves on the inner side of the rigid outer tube not only increase the pipe's compressive strength but also effectively prevent the bamboo fiber wrapping from slipping. This design allows the bamboo fiber layer to fit tightly between the rigid inner and outer tubes when subjected to external forces, improving overall structural stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic cross-sectional view of a composite tube of the present invention;

[0028] FIG2 is an enlarged view of point A in FIG1 ;

[0029] FIG3 is a flow chart of the manufacturing method of the present invention.

[0030] In the figure: 1. Hard inner tube; 2. Bump; 3. Resin; 4. Bamboo fiber winding layer; 5. Hard outer tube. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0032] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0034] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] As shown in FIG1-2 , this embodiment provides a bamboo fiber wound composite tube, which comprises, from the inside to the outside, a hard inner tube 1 , a bamboo fiber wound layer 4 , and a hard outer tube 5 ;

[0036] A plurality of protrusions 2 are arranged in an annular array on the outer wall of the hard inner tube 1. The length direction of the protrusions 2 is consistent with the axial direction of the hard inner tube 1. The protrusions 2 protrude outward along the radial direction of the hard inner tube 1. The protrusions 2 are arranged at intervals. Resin 3 is filled between adjacent protrusions 2. A bamboo fiber winding layer 4 is wound around each protrusion 2. By providing a circular array of protrusions 2 on the outer side of the inner tube, filling the spaces between the protrusions 2 with resin 3, and then winding the bamboo fiber layer, the overall mechanical strength of the pipe is significantly enhanced. The natural corrosion resistance of the bamboo fiber and the chemical stability of the resin 3 work together to ensure that the composite pipe can be used for a long time without corrosion even in harsh environments.

[0037] The inner wall of the hard outer tube 5 is provided with a plurality of V-shaped grooves arranged in a circular array. The length direction of the V-shaped grooves is consistent with the axial direction of the hard outer tube 5. The V-shaped groove design on the inner side of the hard outer tube 5 not only increases the compressive resistance of the pipe, but also effectively prevents the slippage of the bamboo fiber winding layer 4, thereby improving the structural stability.

[0038] This bamboo fiber-wound composite pipe has a hard inner tube 1 as the basic support structure. The protrusions 2 on it increase the contact area with the bamboo fiber winding layer 4, thereby improving the bonding force and mechanical bite effect. The resin 3 between the protrusions 2 not only fixes the bamboo fiber layer, but also forms an additional anti-corrosion layer. The bamboo fiber layer is tightly wound on the protrusions 2, and the high strength and corrosion resistance of the bamboo material itself are utilized to provide the composite pipe with the main mechanical properties and resistance to environmental aging. At the same time, the natural texture of the bamboo fiber helps the penetration and curing of the resin 3, forming a solid overall structure. The hard outer tube 5 serves as the outermost layer of protection to resist external physical impact and chemical erosion. The V-groove design on its inner side, on the one hand, increases the radial compressive strength of the pipe. On the other hand, the groove structure can effectively lock the bamboo fiber layer, preventing it from slipping or delamination during long-term use, thereby ensuring the long-term stability of the pipe.

[0039] As shown in FIG3 , this embodiment further provides a method for manufacturing a bamboo fiber wound composite tube, which is used to manufacture the above-mentioned bamboo fiber wound composite tube, comprising the following steps:

[0040] a. Prepare a hard inner cylinder 1 and arrange multiple protrusions 2 in a circular array on its outer wall, ensuring that the length direction of the protrusions 2 is consistent with the axial direction of the hard inner cylinder 1, and the protrusions 2 are radially outwardly convex along the hard inner cylinder 1, and the protrusions 2 are spaced apart;

[0041] b. Inject uncured resin 3 between adjacent bumps 2. With the surface tension of the resin 3, the uncured resin 3 protrudes above the two bumps 2 but does not overflow, so that the liquid surface of the resin 3 is arched and maintains this shape until the resin 3 is cured;

[0042] c. After the resin 3 is cured, the arched surface of the resin block 3 is polished so that the protruding portion of the resin 3 matches the V-groove shape on the inner wall of the hard outer cylinder 5 to be installed later, to ensure good structural stability and corrosion resistance;

[0043] d. Tightly wrap the bamboo fiber layer around the polished resin block 3 and the protrusion 2, utilizing the high strength and corrosion resistance of bamboo to enhance the mechanical properties and environmental aging resistance of the composite pipe;

[0044] e. Prepare a hard outer cylinder 5 and open a plurality of V-shaped grooves on its inner wall in accordance with a circular array arrangement, ensuring that the length direction of the V-shaped groove is consistent with the axial direction of the hard outer cylinder 5;

[0045] f. The inner tube structure wrapped with a bamboo fiber layer is inserted into the hard outer tube 5, so that the outer surface of the bamboo fiber layer is in close contact with the V-groove inside the hard outer tube 5 to form a stable composite structure;

[0046] g. Carry out necessary sorting and inspection on the composite pipe to ensure that it meets the predetermined quality and performance requirements.

[0047] In this manufacturing method, allowing the resin 3 to protrude above the two protrusions 2 strengthens the bond between the inner and outer layers of the composite tube, preventing the bamboo fiber wrapping layer 4 from slipping or delaminating during long-term use, further improving the long-term stability and corrosion resistance of the tube. Furthermore, polishing ensures that the protruding portion of the resin 3 closely matches the shape of the V-groove, increasing the contact area between the resin 3 and the hard outer tube 5 and thus enhancing their bond. This tight bond helps prevent structural damage caused by stress concentration during use. The V-groove itself is designed to increase the tube's compressive strength and prevent slippage of the inner layer. Polishing the resin 3 to fit the V-groove further ensures that the bamboo fiber wrapping layer 4 is effectively locked between the inner and outer tubes, preventing slippage or delamination during long-term use. Furthermore, the well-matched resin 3 and the V-groove work together to more evenly distribute stress when subjected to external forces, thereby improving the tube's overall strength and fatigue resistance. The V-groove design helps to enhance the radial compressive strength of the pipe, and the three polished resin blocks can better cooperate with the V-groove to jointly withstand external pressure and improve the compressive strength of the pipe.

[0048] In some embodiments, in step c, when processing the resin block 3 with an arched surface, rough cutting is first performed to remove excess resin 3, followed by a fine grinding process to ensure that the surface of the resin block 3 is smooth and perfectly fits the shape of the V-groove without gaps or protrusions. By using a process of rough cutting followed by fine grinding, excess resin 3 can be efficiently removed while ensuring a tight fit between the resin block 3 and the V-groove. This perfect fit without gaps or protrusions not only enhances the structural stability of the pipe, but also effectively prevents external corrosive media from penetrating into the interior of the pipe, thereby improving the corrosion resistance and overall service life of the composite pipe. In addition, this process also helps to improve production efficiency and reduce manufacturing costs.

[0049] In some embodiments, during step d, a device for remotely detecting tension and angle is used to monitor the bamboo fiber layer during winding, ensuring that it is tightly and evenly wound around the resin block 3 and the bumps 2 at the appropriate tension and angle, without any loosening or excessive tension. By using a device for remotely detecting tension and angle, the winding process of the bamboo fiber layer can be monitored in real time to ensure that it is tightly and evenly wound around the resin block 3 and the bumps 2 at the appropriate tension and angle. This precise winding method not only strengthens the bonding between the bamboo fiber layer, the resin block 3, and the bumps 2, but also improves the overall strength and stability of the composite pipe. Furthermore, real-time monitoring and precise control help reduce stress concentration, preventing structural damage caused by excessive localized stress during use, thereby further extending the service life of the composite pipe. Furthermore, the use of remote detection equipment helps improve production efficiency and reduce errors and waste caused by human factors.

[0050] In some embodiments, in step b, when injecting uncured resin 3 between adjacent bumps 2, first ensure that the gap between the bumps 2 is uniform and clean without impurities, and then use precise metering equipment to slowly and evenly inject the uncured resin 3 into the gap until the surface of the resin 3 forms an arch slightly protruding above the bump 2, and maintain this shape until the resin 3 is completely cured. By ensuring that the gap between the bumps 2 is uniform and clean without impurities, and using precise metering equipment to slowly and evenly inject the uncured resin 3 into the gap, it is possible to ensure that the resin 3 can form a uniform and strong bonding layer after curing. This uniform layer of resin 3 not only enhances the overall structural strength of the composite pipe, but also effectively prevents stress concentration and structural damage caused by uneven distribution of resin 3.

[0051] In some embodiments, in step f, when inserting the inner cylinder structure wrapped with the bamboo fiber layer into the hard outer cylinder 5, a laser positioning device is used to ensure precise alignment between the inner cylinder structure and the hard outer cylinder 5, so that the outer surface of the bamboo fiber layer and the V-shaped groove inside the hard outer cylinder 5 are accurately aligned and closely contacted without offset or misalignment. This ensures precise alignment between the inner cylinder structure and the hard outer cylinder 5.

[0052] In some embodiments, during the necessary finishing and inspection of the composite pipe in step g, non-destructive testing techniques, such as ultrasonic testing or X-ray testing, are employed to comprehensively inspect the overall structure and internal quality of the composite pipe to ensure that it is free of defects such as cracks, delamination, or bubbles, and that all performance indicators meet predetermined quality and performance requirements. By employing non-destructive testing techniques, such as ultrasonic testing or X-ray testing, to comprehensively inspect the composite pipe in step g, it is possible to ensure that the overall structure and internal quality of the composite pipe meet predetermined standards. This comprehensive testing approach not only detects potential defects such as cracks, delamination, and bubbles, but also ensures that all performance indicators of the composite pipe meet predetermined quality and performance requirements. This rigorous testing procedure helps improve the production quality of the composite pipe, reduce scrap rates, and ensure the reliability and durability of the final product. Furthermore, the use of non-destructive testing techniques helps improve production efficiency and reduces the additional costs and time associated with repeated inspections or repairs.

[0053] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A bamboo fiber wound composite pipe, characterized by: From the inside to the outside, it includes a hard inner tube (1), a bamboo fiber winding layer (4), and a hard outer tube (5); A plurality of protrusions (2) are arranged in a ring array on the outer wall of the hard inner tube (1), the length direction of the protrusions (2) is consistent with the axial direction of the hard inner tube (1), the protrusions (2) protrude outward along the radial direction of the hard inner tube (1), the protrusions (2) are arranged at intervals, and resin (3) is filled between adjacent protrusions (2), and the bamboo fiber winding layer (4) is wound on each protrusion (2); A plurality of V-shaped grooves are arranged in a circular array on the inner side wall of the hard outer cylinder (5), and the length direction of the V-shaped grooves is consistent with the axial direction of the hard outer cylinder (5).

2. A method for manufacturing a bamboo fiber wound composite pipe, used to manufacture the bamboo fiber wound composite pipe according to claim 1, characterized in that: The following steps are involved: a. Prepare a hard inner cylinder (1), and arrange a plurality of protrusions (2) on its outer wall in a circular array, ensuring that the length direction of the protrusions (2) is consistent with the axial direction of the hard inner cylinder (1), and the protrusions (2) protrude outward along the radial direction of the hard inner cylinder (1), and the protrusions (2) are arranged at intervals; b. injecting uncured resin (3) between adjacent protrusions (2), and making the uncured resin (3) protrude above the two protrusions (2) without overflowing due to the surface tension of the resin (3), so that the liquid surface of the resin (3) is arched and maintains this shape until the resin (3) is cured; c. After the resin (3) is solidified, the arched surface of the resin (3) block is polished so that the protruding portion of the resin (3) matches the shape of the V-shaped groove on the inner wall of the hard outer cylinder (5) to be installed later, so as to ensure good structural stability and corrosion resistance; d. Tightly wrapping a bamboo fiber layer around the polished resin (3) block and the protrusion (2), utilizing the high strength and corrosion resistance of bamboo to enhance the mechanical properties and environmental aging resistance of the composite pipe; e. Prepare a hard outer cylinder (5), and open a plurality of V-shaped grooves on its inner wall in a circular array, ensuring that the length direction of the V-shaped groove is consistent with the axial direction of the hard outer cylinder (5); f. The inner tube structure wrapped with a bamboo fiber layer is inserted into the hard outer tube (5), so that the outer surface of the bamboo fiber layer is in close contact with the V-groove inside the hard outer tube (5), forming a stable composite structure; g. Carry out necessary sorting and inspection on the composite pipe to ensure that it meets the predetermined quality and performance requirements.

3. The method for manufacturing a bamboo fiber-wound composite pipe according to claim 2, characterized in that: In step c, when processing the resin (3) block with an arched surface, rough cutting is first performed to remove excess resin (3), followed by a fine grinding process.

4. The method for manufacturing a bamboo fiber-wound composite pipe according to claim 2, characterized in that: In step d, when winding the bamboo fiber layer, a device for remotely detecting tension and angle is used to monitor in real time and ensure that the bamboo fiber layer is tightly and evenly wound with appropriate tension and angle.

5. The method for manufacturing a bamboo fiber-wound composite pipe according to claim 2, characterized in that: In step b, when injecting uncured resin (3) between adjacent bumps (2), first ensure that the gap between the bumps (2) is uniform and clean without impurities, and then use precise metering equipment to slowly and evenly inject the uncured resin (3) into the gap.

6. The method for manufacturing a bamboo fiber-wound composite pipe according to claim 2, characterized in that: In step f, when the inner cylinder structure wrapped with the bamboo fiber layer is inserted into the hard outer cylinder (5), a laser positioning device is used to ensure accurate alignment between the inner cylinder structure and the hard outer cylinder (5).

7. The method for manufacturing a bamboo fiber-wound composite pipe according to claim 2, characterized in that: In step g, when the composite pipe is subjected to necessary sorting and inspection, a non-destructive testing technology is used to conduct a comprehensive inspection of the overall structure and internal quality of the composite pipe.

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