A porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe and a preparation method thereof

Abstract

The application discloses a kind of porous aluminum strip butt welding reinforced chlorinated polyvinyl chloride composite pipe and its preparation method, steps include aluminum strip uncoiling, punching, cleaning, trimming, PVC-C core pipe preparation and coating solid-state reaction type polyurethane hot melt adhesive, aluminum strip cladding core pipe, laser butt welding, high-frequency heating, aluminum strip reinforced pipe coating PUR hot melt adhesive, PVC-C outer pipe co-extrusion forming, cooling, corona treatment and post-processing of finished product.The method forms hot melt adhesive penetration hole by punching aluminum strip, cooperates with trimming to ensure welding quality, strengthens hot melt adhesive penetration anchoring effect by high-frequency heating, improves the bonding strength of aluminum strip reinforced pipe and PVC-C layer, avoids interlayer separation, balances internal and external stress of pipe to reduce thermal expansion and contraction deformation.

Description

Technical Field

[0001] This invention relates to the field of chlorinated polyvinyl chloride composite pipes, specifically to a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe and its preparation method. Background Technology

[0002] Chlorinated polyvinyl chloride (PVC) pipes are widely used in domestic hot and cold water supply, fire sprinkler systems, and industrial water supply due to their high rigidity, excellent internal pressure resistance, good heat resistance, and corrosion resistance. To further enhance their pressure resistance and structural stability, the industry often uses aluminum strip reinforcement technology, which combines aluminum strip with PVC-C substrate to form a composite pipe that combines the strength of metal with the corrosion resistance of plastic, namely aluminum strip reinforced PVC-C pipes.

[0003] However, existing aluminum strip reinforced PVC-C pipes have significant technical shortcomings. Firstly, the bonding strength between the aluminum strip and the PVC-C core is insufficient. Traditional processes often use non-porous aluminum strips, relying solely on hot melt adhesive for surface bonding, which easily leads to delamination between layers. This is especially problematic under long-term thermal cycling or high-pressure conditions, significantly reducing the pipe's sealing and pressure-bearing capacity, making it difficult to meet the demands of demanding applications. Secondly, defects exist in the aluminum strip processing. Unprecisely trimmed aluminum strip edges are prone to retaining burrs and impurities, resulting in loose adhesion at the aluminum strip joints during subsequent laser butt welding, leading to a high welding defect rate and directly affecting the integrity of the reinforcing layer structure. Furthermore, poor uniformity of hot melt adhesive coating in some production processes further exacerbates the unstable interlayer bonding, hindering the performance improvement and application expansion of aluminum strip reinforced PVC-C pipes. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the background art and provide a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe and its preparation method.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A method for preparing a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe includes the following steps:

[0007] S1, Drilling: The aluminum strip is uncoiled in sequence and punched through the punching device of the composite tube production equipment to form hot melt adhesive penetration holes. Then, the surface of the aluminum strip is cleaned by the cleaning device of the composite tube production equipment to remove impurities.

[0008] S2, Trimming: The perforated aluminum strip is trimmed by the trimming device of the composite pipe production equipment.

[0009] S3, PVC-C core tube preparation: PVC-C raw materials are extruded into PVC-C core tubes using a twin-screw extruder;

[0010] S4, Core tube coated with hot melt adhesive: The PVC-C core tube is coated with solid reactive polyurethane hot melt adhesive. The hot melt adhesive is melted by the first PUR gluing device of the composite tube production equipment and injected into the co-extrusion mold through the nozzle, and evenly coated on the surface of the core tube.

[0011] S5, Aluminum strip-coated core tube: After trimming, the aluminum strip is passed through the forming device of the composite tube production equipment, and a PVC-C core tube coated with hot melt adhesive is placed above the aluminum strip. This allows the aluminum strip to wrap the plastic tube as it gradually bends and curls into a tube shape. Then, the tubular aluminum strip is laser butt welded to form an aluminum strip-reinforced tube on the surface of the core tube.

[0012] S6, High-frequency heating: The PVC-C core tube covered with aluminum strip reinforced tube is heated by the high-frequency heating device of the composite pipe production equipment, and then PUR hot melt adhesive is applied to the surface of the aluminum strip again by the second PUR adhesive device according to the adhesive application principle of step 4.

[0013] S7, Outer layer preparation: The PVC-C outer tube is co-extruded and then extruded through the outer layer extrusion device of the composite pipe production equipment to form a composite pipe by covering the coated aluminum strip reinforcement layer.

[0014] This invention creates continuous hot melt adhesive penetration holes on the surface of the aluminum strip through a drilling process. Afterwards, burrs and impurities are removed from the edges of the aluminum strip. This ensures a tight fit at the joint of the aluminum strip during subsequent laser butt welding, reducing welding defects. The core tube is then coated with hot melt adhesive, and the aluminum strip wraps around the core tube. High-frequency heating completes the outer layer preparation. The pores allow for the penetration and anchoring of the hot melt adhesive. High-frequency heating melts the hot melt adhesive, strengthening the bond and improving the bonding strength between the aluminum strip reinforced tube and the PVC-C core tube. This avoids the interlayer delamination problem that often occurs with traditional non-porous aluminum strips. It boasts strong pressure resistance, convenient connection, and can be widely used in household hot and cold water supply pipes, fire sprinkler pipes, and industrial water pipelines. Furthermore, the pores balance internal and external stresses during pipe forming and use, reducing structural deformation caused by thermal expansion and contraction and extending the service life of the pipe.

[0015] Preferably, the composite pipe production equipment includes a frame and a punching device, a cleaning device, a trimming device, a forming device, a high-frequency heating device, a second PUR coating device, an outer layer extrusion device, a twin-screw extrusion mechanism, and a first PUR coating device mounted on the frame. The punching device, cleaning device, trimming device, forming device, high-frequency heating device, and second PUR coating device are arranged sequentially. The twin-screw extrusion mechanism and the first PUR coating device are arranged sequentially and located to the right of the punching device. The entire equipment is also equipped with a traction machine.

[0016] This invention forms a continuous aluminum strip processing flow through the sequential arrangement of a punching device, a cleaning device, and a trimming device. Punching, impurity removal, and trimming can be completed without additional transport, reducing process intervals, improving aluminum strip processing accuracy, and laying the foundation for subsequent forming and welding. The forming device can bend the aluminum strip into an aluminum tube. A screw extrusion mechanism and a first PUR gluing device are arranged sequentially to the right of the punching device, simultaneously completing the preparation and gluing of the PVC-C core tube. This efficiently connects with the aluminum strip processing flow, achieving precise matching and coating of the core tube and the aluminum strip reinforcing tube. A second PUR gluing device and an outer extrusion device can then coat the PVC-C coated tube onto the aluminum strip reinforcing tube, finally producing a composite tube. The entire process involves coordinated equipment work, ensuring reliable bonding and pressure resistance of each layer of the tube while reducing production energy consumption and operational complexity, meeting the needs of large-scale production.

[0017] Preferably, both the first and second PUR coating devices include a screw extrusion mechanism. The extrusion port of the screw extrusion mechanism is provided with a detachable uniform co-extrusion die. The detachable uniform co-extrusion die includes a connecting pipe, an annular extrusion tube, a heating ring, an upper half-insulating ring, and a lower half-insulating ring. The heating ring is located on the outside of the annular extrusion tube, and the connecting pipe is located on both sides of the annular extrusion tube. The upper and lower half-insulating rings are located on the outside of the connecting pipe. Semi-through grooves are provided on the left and right sides of the heating ring. Limiting posts are provided on the left and right sides of the annular extrusion tube, one of which is a glue inlet pipe. Fixing posts are provided on the inner sides of the upper and lower half-insulating rings. Limiting holes that cooperate with the fixing posts are provided on the connecting pipe. The upper and lower half-insulating rings are connected by bolts.

[0018] The annular extrusion tube includes an annular tube body, the inner sidewall of which has a plurality of glue outlet holes along the circumferential direction, and the outer sidewall of which is fixed with the glue inlet tube.

[0019] This invention uses a screw extrusion mechanism to extrude hot melt adhesive, which is then extruded through a detachable, uniform co-extrusion die via an annular extrusion tube. Under the action of a heating ring and a heat-insulating ring, the hot melt adhesive does not solidify. When the tube enters through the annular extrusion tube from the connecting tube, the hot melt adhesive can be extruded from the outlet hole and uniformly coated onto the tube, thus completing the continuous coating process during tube production. Simultaneously, the upper and lower heat-insulating rings are connected by bolts, and a limiting post is placed in a semi-through groove. The connecting tube abuts against the semi-through groove, and the fixing post is inserted into the limiting hole, making the entire assembly easy to disassemble and facilitate subsequent cleaning.

[0020] Preferably, the punching device includes a worktable, a first guide wheel, a second guide wheel, and a laser. The first guide wheel is disposed on the side of the worktable, the second guide wheel is disposed on the upper surface of the worktable, the laser is disposed above the worktable, and a waste trough is provided on the worktable at a position relative to the laser.

[0021] The present invention uses a first guide wheel and a second guide wheel to allow the aluminum strip to pass through the laser. When the laser works, it punches holes in the aluminum strip. Afterwards, the waste material falls into the waste trough, so that the aluminum strip can complete the punching work as it moves forward.

[0022] Preferably, the trimming device includes two relatively rotating rollers, a left waste collection roller, a left guide roller group, a right waste collection roller, and a right guide roller group. One of the rotating rollers has a groove on its roller surface along the circumferential direction, and the other rotating roller has a protrusion on its roller surface. The groove and the protrusion are positioned and matched in shape. A material feeding gap is formed between the two rotating rollers. The left waste collection roller and the left guide roller group are located on the left side of the rotating roller, and the right waste collection roller and the right guide roller group are located on the right side of the rotating roller.

[0023] This invention uses the grooves and recesses on the rotating rollers to form a cutting area, so that when the aluminum strip passes through the feed gap, both sides of the aluminum strip are cut out. The waste on the left side is collected by winding it onto the left waste collection roller through the left guide roller group, and the waste on the right side is collected by winding it onto the right waste collection roller through the right guide roller group. This allows the aluminum strip to move forward while being trimmed and burrs and impurities on the edges of the aluminum strip are removed. In the subsequent laser butt welding process, this ensures that the aluminum strip joints fit tightly and reduces welding defects.

[0024] Preferably, the forming device includes a transition roller group, a pre-bending mechanism, a first shrink tube, a second shrink tube, a laser welding mechanism, and a weld position detection mechanism, which are sequentially arranged on the frame. The transition roller group includes a left support plate, a right support plate, a left transition roller, and a right transition roller. The left support plate and the right support plate are fixed on the frame. A plurality of the left transition rollers are rotatably arranged in a linear array on the left support plate, and a plurality of the right transition rollers are rotatably arranged in a linear array on the right support plate. The laser welding mechanism includes a slide rail and a laser welding head that slides left and right on the slide rail.

[0025] The weld location detection mechanism includes an image acquisition module, which is used to take pictures of the workpiece containing the weld and obtain image data of the weld area;

[0026] An image processing module, connected to the image acquisition module, is used to preprocess the image data and extract the feature information of the weld, including the geometric contour, position coordinates and size parameters of the weld.

[0027] A standard database stores preset standard weld position parameters;

[0028] The comparison and judgment module is connected to the image processing module and the standard database respectively, and is used to compare the weld position coordinates extracted by the image processing module with the standard position parameters in the standard database and calculate the position deviation value.

[0029] The result output module is connected to the comparison and judgment module and is used to output a judgment result on whether the weld position is accurate based on the position deviation value.

[0030] This invention uses a transition roller group to allow the trimmed aluminum strip to be laid flat into a pre-bending mechanism, where it is then bent upwards. After passing through a first shrink tube and a second shrink tube, it forms a circular tube. A laser welding mechanism then performs laser welding on the gap. A weld position detection mechanism checks the accuracy of the welding position. When a deviation is detected, the laser welding head moves along a slide rail to ensure the accuracy of the welding position and the precision of the welding.

[0031] Preferably, the cleaning device includes a housing, a cleaning brush roller, a vacuum suction roller, a dust collection pipe, a waste collection trough, and a support roller. The housing has through holes on both sides to facilitate the passage of aluminum strips. The cleaning brush roller is positioned above the support roller and is rotatably mounted on the side wall of the housing. The vacuum suction roller is positioned behind the support roller and rotatably connected to the side wall of the housing. The waste collection trough is located below the vacuum suction roller. The dust collection pipe extends from the side of the cleaning brush roller to the outside of the housing. The roller includes a hollow outer roller and a hollow inner roller, with a cavity between the outer and inner rollers. The outer and inner rollers are coaxial. The inner roller has a suction hole on its side wall, and the outer roller has an adsorption hole. The waste collection trough includes a trough body with a top opening. A partition is provided in the middle of the trough body, and a waste inlet is formed between the partition and the side wall of the trough body. An upwardly inclined scraper is provided on one side of the partition. An air intake is provided at the bottom left side of the trough body, and a filter screen is provided on the air intake.

[0032] This invention pre-treats the aluminum strip using a cleaning brush roller, which removes larger particles, surface dust, and other loose impurities. After pre-treatment, impurities adhering to the cleaning brush roller are sucked away through a suction pipe. The aluminum strip then passes through a vacuum adsorption roller, which features a hollow inner and outer double-roller design. The adsorption holes of the outer roller and the suction holes of the inner roller work together to form a negative pressure adsorption structure, precisely adsorbing impurities such as punching debris and dust from the aluminum strip surface. This efficient cleaning prevents impurities from affecting subsequent trimming, welding, and hot melt adhesive bonding quality, ensuring the stability of the bond between the aluminum strip reinforcement layer and the PVC-C layer.

[0033] The waste collection trough features a partition and scraper design. The scraper guides the waste transferred by the adsorption roller to the waste inlet, achieving orderly waste collection. The bottom air intake on the left side helps to adsorb residual waste, preventing waste accumulation from polluting the production environment or causing secondary adhesion of aluminum strips, thus reducing rework in the cleaning process.

[0034] A porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe includes a PVC-C core pipe, a PVC-C coated pipe, and an aluminum strip reinforcing pipe. The aluminum strip reinforcing pipe is disposed between the PVC-C core pipe and the PVC-C coated pipe. The PVC-C core pipe, the PVC-C coated pipe, and the aluminum strip reinforcing pipe are bonded together by solid reactive polyurethane hot melt adhesive.

[0035] This invention employs a solid reactive polyurethane hot melt adhesive to bond a three-layer structure, effectively solving the technical challenge of ordinary hot melt adhesives failing to stably bond PVC-C to metal. Combined with the porous structure of the aluminum strip-reinforced pipe, the hot melt adhesive can penetrate and create an anchoring effect, achieving a strong bond between the three layers and ensuring the pipe does not delaminate during long-term use. Simultaneously, the inner and outer PVC-C layers allow for rapid connection of the pipe to PVC-C fittings using specialized adhesives, reducing construction costs. This invention combines high performance with practicality. Furthermore, using PVC-C as the inner and outer layers ensures safety and hygiene. PVC-C is a high-end material for drinking water and fire-fighting water pipes, exhibiting excellent weather resistance and flame retardancy.

[0036] In summary, the beneficial effects of this invention are as follows:

[0037] 1. This invention creates continuous hot melt adhesive penetration holes on the surface of the aluminum strip through a drilling process. Afterwards, burrs and impurities on the edges of the aluminum strip are removed through trimming. This ensures a tight fit at the joint of the aluminum strip during subsequent laser butt welding, reducing welding defects. The core tube is then coated with hot melt adhesive, and the aluminum strip wraps around the core tube. High-frequency heating completes the outer layer preparation. The pores allow for the penetration and anchoring of the hot melt adhesive. High-frequency heating melts the hot melt adhesive, strengthening the bond and improving the bonding strength between the aluminum strip reinforced tube and the PVC-C core tube. This avoids the interlayer delamination problem that often occurs with traditional non-porous aluminum strips. It has strong pressure resistance, is easy to connect, and can be widely used in household hot and cold water supply pipes, fire sprinkler pipes, and industrial water pipelines. Furthermore, the pores balance internal and external stresses during pipe forming and use, reducing structural deformation caused by thermal expansion and contraction and extending the service life of the pipe.

[0038] 2. This invention uses a screw extrusion mechanism to extrude hot melt adhesive, which is then extruded from an annular extrusion tube through the glue inlet tube of a detachable uniform co-extrusion die. Under the action of the heating ring and the heat preservation ring, the hot melt adhesive will not solidify. When the tube enters from the connecting tube and passes through the annular extrusion tube, the hot melt adhesive can be extruded from the glue outlet and uniformly coated on the tube, thereby completing the function of continuous glue coating of the tube during the production process. At the same time, the upper half heat preservation ring and the lower heat preservation ring are connected by bolts, the limiting post is placed in the semi-through groove, the connecting tube abuts against the semi-through groove, and the fixing post is inserted into the limiting hole, making the whole assembly easy to disassemble and easy to clean later.

[0039] 3. This invention uses a transition roller group to allow the trimmed aluminum strip to be laid flat into the pre-bending mechanism, then bent upwards by the pre-bending mechanism, and then formed into a circular tube by the first shrink tube and the second shrink tube. Then, the gap is laser welded by the laser welding mechanism. After that, the weld position detection mechanism detects whether the welding position is accurate. When a deviation is detected, the laser welding head moves through the slide rail, thereby ensuring the accuracy of the welding position and ensuring the precision of the welding.

[0040] 4. This invention employs a solid reactive polyurethane hot melt adhesive to bond a three-layer structure, effectively solving the technical problem that ordinary hot melt adhesives cannot stably bond PVC-C to metal. Combined with the porous structure of the aluminum strip-reinforced pipe, the hot melt adhesive can penetrate and form an anchoring effect, achieving a strong bond between the three layers and ensuring the pipe does not delaminate during long-term use. Simultaneously, the inner and outer PVC-C layers allow the pipe to be quickly connected to PVC-C fittings using specialized adhesives, reducing construction costs. It combines high performance and practicality. Furthermore, using PVC-C as the inner and outer layers ensures safety and hygiene. PVC-C is a high-end material for drinking water and fire-fighting water pipes, offering excellent weather resistance and flame retardancy. Attached Figure Description

[0041] Figure 1 This is an overall schematic diagram of the composite pipe production equipment of the present invention;

[0042] Figure 2 This is a side view of the composite pipe production equipment of the present invention;

[0043] Figure 3 This is a schematic diagram of the detachable uniform co-extrusion mold of the present invention;

[0044] Figure 4 This is a schematic diagram showing the disassembly of the detachable uniform co-extrusion mold of the present invention;

[0045] Figure 5 This is a schematic diagram of the annular extrusion tube of the present invention;

[0046] Figure 6 This is a schematic diagram of the punching device of the present invention;

[0047] Figure 7 This is a schematic diagram of the trimming device and the forming device of the present invention;

[0048] Figure 8 This is a cross-sectional schematic diagram of the cleaning device of the present invention;

[0049] Figure 9 This is a schematic diagram of the high-frequency heating device of the present invention;

[0050] Figure 10 This is a schematic diagram of the pipe material of the present invention;

[0051] Figure 11 This is a cross-sectional schematic diagram of the pipe material of the present invention;

[0052] 105. Composite pipe production equipment; 10. Frame; 1. Punching device; 6. Cleaning device; 2. Trimming device; 4. Forming device; 5. High-frequency heating device; 8. Second PUR coating device; 7. Outer layer extrusion device; 9. Twin-screw extrusion mechanism; 3. First PUR coating device; 81. Screw extrusion mechanism; 82. Detachable uniform co-extrusion die; 821. Connecting pipe; 822. Annular extrusion tube; 823. Heating ring; 824. Upper half insulation ring; 825. Lower half insulation ring; 826. Semi-through groove; 827. Limiting post; 828. Fixing post; 829. Limiting hole; 820. Annular tube; 830. Glue outlet; 11. Worktable; 12. First guide wheel; 13. Second guide wheel; 14. Laser; 15. Waste trough; 21. Rotating roller; 22. Left waste collection roller; 23. Left guide roller group; 24. Right waste 25. Collecting roller; 211. Right guide roller assembly; 212. Groove; 26. Material feed gap; 41. Transition roller assembly; 42. Pre-bending mechanism; 43. First shrink tube; 44. Second shrink tube; 45. Laser welding mechanism; 46. Weld position detection mechanism; 411. Left support plate; 412. Right support plate; 413. Left transition roller; 414. Right transition roller; 451. Slide rail; 452. Laser welding 61. Head; 62. Box body; 63. Cleaning brush roller; 64. Vacuum adsorption roller; 65. Dust suction pipe; 66. Waste collection trough; 67. Support roller; 68. Through hole; 69. Outer roller; 60. Inner roller; 61. Cavity; 62. Suction hole; 63. Adsorption hole; 64. Tank body; 65. Partition plate; 655. Waste inlet; 66. Scraper; 67. Air inlet; 100. PVC-C core tube; 101. PVC-C coated tube; 102. Aluminum strip reinforced tube; 104. Solid reactive polyurethane hot melt adhesive; 103. Hot melt adhesive penetration hole. Detailed Implementation

[0053] The following specific embodiments are merely illustrative of the present invention and are not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of the present invention.

[0054] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0055] Example 1

[0056] A method for preparing a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe includes the following steps:

[0057] S1, Drilling: The aluminum strip is uncoiled in sequence, punched by the punching device 1 of the composite tube production equipment 105, and then the surface of the aluminum strip is cleaned by the cleaning device 6 of the composite tube production equipment 105 to remove impurities.

[0058] S2, trimming: The perforated aluminum strip is trimmed by the trimming device 2 of the composite pipe production equipment 105.

[0059] S3, PVC-C core tube preparation: Chlorinated polyvinyl chloride resin is mixed with 5-8 parts MBS toughening agent, 2.5-3.0 parts organotin stabilizer, 2.0-3.5 parts titanium dioxide, 0.3-0.8 parts ester lubricant, 1.5-2.5 parts external lubricant, 0.4-0.8 parts OPE wax, and 1.0-2.0 parts processing ACR, and then extruded via twin-screw extrusion to produce PVC-C core tubes;

[0060] S4, Core tube coated with hot melt adhesive: The PVC-C core tube is coated with solid reactive polyurethane hot melt adhesive. The hot melt adhesive is melted by the first PUR gluing device 3 of the composite tube production equipment 105 and injected into the co-extrusion mold through the nozzle, and evenly coated on the surface of the core tube.

[0061] S5, Aluminum strip-wrapped core tube: After trimming, the aluminum strip is rolled by multiple concave and convex rollers of the forming device 4 of the composite tube production equipment 105, causing both sides to gradually bend upwards into a tube shape. At the same time, a PVC-C core tube coated with hot melt adhesive is passed through the forming device 4 of the composite tube production equipment 105 above the aluminum strip, so that the aluminum strip can wrap the plastic tube when it bends upwards. Then, the tubular aluminum strip is laser butt welded to form an aluminum strip reinforced tube on the surface of the core tube.

[0062] S6, High-frequency heating: The PVC-C core tube covered with aluminum strip reinforced tube is heated by high-frequency heating device 5 of composite pipe production equipment 105, and then PUR hot melt adhesive is applied to the surface of aluminum strip again by second PUR adhesive device 8 according to the adhesive application principle of step 4.

[0063] S7, Outer layer preparation: The PVC-C outer pipe is co-extruded and extruded. The outer layer is covered with an aluminum strip reinforcement layer after being coated with glue through the outer layer extrusion device 7 of the composite pipe production equipment 105. Then it is cooled and shaped, and then the surface of the pipe is subjected to corona treatment.

[0064] S8, Post-processing of finished products: After that, inkjet printing is performed to obtain composite pipes.

[0065] like Figures 1-2 As shown, the composite pipe production equipment 105 includes a frame 10 and a punching device 1, a cleaning device 6, a trimming device 2, a forming device 4, a high-frequency heating device 5, a second PUR coating device 8, an outer layer extrusion device 7, a twin-screw extrusion mechanism 9, and a first PUR coating device 3, all mounted on the frame 10. The punching device 1, cleaning device 6, trimming device 2, forming device 4, high-frequency heating device 5, and second PUR coating device 8 are arranged sequentially. The twin-screw extrusion mechanism 9 and the first PUR coating device 3 are arranged sequentially and located to the right of the punching device 1. The outer layer extrusion device uses a twin-screw extrusion mechanism and a detachable uniform co-extrusion mold.

[0066] like Figures 3-5 As shown, both the first PUR coating device 3 and the second PUR coating device 8 include a screw extrusion mechanism 81. The extrusion port of the screw extrusion mechanism 81 is provided with a detachable uniform co-extrusion die 82. The detachable uniform co-extrusion die 82 includes a connecting pipe 821, an annular extrusion tube 822, a heating ring 823, an upper half heat-insulating ring 824, and a lower half heat-insulating ring 825. The heating ring 823 is located outside the annular extrusion tube 822, the connecting pipe 821 is located on both sides of the annular extrusion tube 822, and the upper half heat-insulating ring 824 and the lower half heat-insulating ring 825 are located outside the connecting pipe 821. The heating ring 823 has openings on both the left and right sides. The annular extrusion tube 822 is provided with a semi-through groove 826. Limiting posts 827 are provided on the left and right sides of the annular extrusion tube 822. One of the limiting posts 827 is an inlet tube. The inner side of the upper half insulation ring 824 and the lower half insulation ring 825 is provided with fixing posts 828. The connecting tube 821 is provided with limiting holes 829 that cooperate with the fixing posts 828. The upper half insulation ring 824 and the lower half insulation ring 825 are connected by bolts. The annular extrusion tube 822 includes an annular tube body 820. The inner side wall of the annular tube body 820 is provided with a plurality of glue outlet holes 830 along the circumferential direction. The inlet tube is fixed to the outer side wall of the annular tube body 820.

[0067] like Figure 6As shown, the punching device 1 includes a worktable 11, a first guide wheel 12, a second guide wheel 13, and a laser 14. The first guide wheel 12 is disposed on the side of the worktable 11, the second guide wheel 13 is disposed on the upper surface of the worktable 11, and the laser 14 is disposed above the worktable 11. A waste trough 15 is provided on the worktable 11 at a position relative to the laser 14.

[0068] like Figure 7 As shown, the trimming device 2 includes two relatively rotating rollers 21, a left waste collection roller 22, a left guide roller group 23, a right waste collection roller 24, and a right guide roller group 25. One of the rotating rollers 21 has a groove 211 along its circumferential direction on its roller surface, and the other rotating roller 21 has a protrusion 212 on its roller surface. The groove 211 and the protrusion 212 are positioned correspondingly and matched in shape. A material feeding gap 26 is formed between the two rotating rollers 21. The left waste collection roller 22 and the left guide roller group 23 are located to the left of the rotating roller 21. The right waste collection roller 24 and the right guide roller group 25 are located on the right side of the rotating roller 21. The forming device 4 includes a transition roller group 41, a pre-bending mechanism 42, a first shrink tube 43, a second shrink tube 44, a laser welding mechanism 45, and a weld position detection mechanism 46, which are sequentially arranged on the frame 10. The transition roller group 41 includes a left support plate 411, a right support plate 412, a left transition roller 413, and a right transition roller 414. The left support plate 411 and the right support plate 412 are fixed on the frame 10. Several left transition rollers 413 can... A rotating linear array is mounted on the left support plate 411, and several right transition rollers 414 are rotatably linearly mounted on the right support plate 412. The laser welding mechanism 45 includes a slide rail 451 and a laser welding head 452 that slides left and right on the slide rail 451. The pre-bending mechanism 42 includes multiple sets of counter-pressing outer convex rollers 421 and inner concave rollers 422. Through continuous rolling pressure by multiple sets of outer convex rollers 421 and inner concave rollers 422, the aluminum plate is continuously bent and curled upwards on both sides. The pre-bending mechanism 42 also includes a vertical plate 423 fixedly mounted on the top of the frame, and outer convex rollers 421 and inner concave rollers 422. The inner concave roller 422 is symmetrically rotated in the vertical plate 423. The outer convex roller 421 has a first clearance groove 424 in the middle and a deformation groove 425 on the outer wall of the outer convex roller 421. The inner wall of the inner concave roller 422 has deformation grooves 426 on both sides. The inclination angle of the multiple sets of deformation grooves 425 and deformation grooves 426 gradually increases. The plastic tube passes through the first clearance groove in sequence, and then the aluminum strip passes through the gaps between the multiple inner concave rollers and the outer convex rollers in sequence, so that the two sides of the aluminum strip gradually curl upward. Then the aluminum strip is continuously shrunk and shaped through multiple shrink tubes.

[0069] like Figure 8As shown, the cleaning device 6 includes a housing 61, a cleaning brush roller 62, a vacuum suction roller 63, a dust collection pipe 64, a waste collection trough 65, and a support roller 66. The housing 61 has through holes 611 on both sides to facilitate the passage of aluminum strip. The cleaning brush roller 62 is positioned above the support roller 66 and is rotatably mounted on the side wall of the housing 61. The vacuum suction roller 63 is positioned behind the support roller 66 and is rotatably connected to the side wall of the housing 61. The waste collection trough 65 is positioned below the vacuum suction roller 63. The dust collection pipe 64 extends from the side of the cleaning brush roller 62 to the outside of the housing 61. The vacuum suction roller 63 includes an internal... The outer roller 631 is hollow and the inner roller 632 is hollow inside. There is a cavity 633 between the outer roller 631 and the inner roller 632. The outer roller 631 and the inner roller 632 are coaxial. The inner roller 632 has a suction hole 634 on its side wall and the outer roller 631 has an adsorption hole 635. The waste collection tank 65 includes a tank body 651 with a top opening. A partition 652 is provided in the middle of the tank body 651. A waste inlet 654 is formed between the partition 652 and the side wall of the tank body 651. An upwardly inclined scraper 653 is provided on one side of the partition 652. An air suction port 655 is provided at the bottom left side of the tank body 651.

[0070] like Figure 9 As shown, the high-frequency heating device 5 includes an insulation box 51 and a high-frequency heating coil 52. The high-frequency heating coil 52 is disposed inside the insulation box 51, and the tube passes through the high-frequency heating coil 52 for heating.

[0071] like Figures 10-11 As shown, a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe includes a PVC-C core pipe 100, a PVC-C coated pipe 101, and an aluminum strip reinforcing pipe 102. The aluminum strip reinforcing pipe 102 is disposed between the PVC-C core pipe 100 and the PVC-C coated pipe 101. The PVC-C core pipe 100, the PVC-C coated pipe 101, and the aluminum strip reinforcing pipe 102 are bonded together with a solid reactive polyurethane hot melt adhesive 104. The aluminum strip reinforcing pipe 102 has a plurality of hot melt adhesive penetration holes 103.

[0072] Working principle: such as Figures 1-11As shown, the aluminum strip is first passed through the first guide wheel 12 and the second guide wheel 13, allowing it to pass flatly through the bottom of the laser 14. The laser operates, punching holes in the aluminum strip. The waste then falls into the waste trough. After punching, the aluminum strip passes through the cleaning device 6. The cleaning brush roller 62 rotates to pre-treat the aluminum strip, removing larger particles, surface dust, and other loose impurities. Impurities adhering to the cleaning brush roller 62 after pre-treatment are sucked away through the suction pipe 64. The aluminum strip then passes through the vacuum adsorption roller 63, which features a hollow inner and outer double roller design. The adsorption holes 635 of roller 631 and the suction holes 634 of inner roller 632, together with the cavity 633, form a negative pressure adsorption structure that can accurately adsorb impurities on the surface of aluminum strip, such as punching debris and dust, thus efficiently completing the cleaning. The design of the partition 652 and scraper 653 in the waste collection trough 65 allows the scraper 653 to guide the waste transferred by the adsorption roller to the waste inlet 654, achieving orderly waste collection. The bottom suction port 655 on the left side can assist in adsorbing residual waste, preventing waste accumulation from polluting the production environment or causing secondary adhesion to the aluminum strip, reducing rework in the cleaning process. Afterwards, the perforated aluminum strip is processed through a composite... The trimming device 2 of the pipe production equipment 105 performs trimming. During the above steps, the screw extrusion mechanism extrudes the hot melt adhesive, which is then extruded from the annular extrusion tube through the glue inlet tube of the detachable uniform co-extrusion die. Under the action of the heating ring and the heat preservation ring, the hot melt adhesive does not solidify. When the PVC-C core tube passes through, the hot melt adhesive can be extruded from the glue outlet and evenly coated on the tube. The trimmed aluminum strip is rolled by multiple concave rollers and convex rollers of the forming device 4 of the composite pipe production equipment 105, causing both sides to gradually bend upwards and bend into a tube shape. At the same time, the PVC-C core tube coated with hot melt adhesive is passed through the composite pipe production equipment 105. The forming device 4 of the tube production equipment 105 is located above the aluminum strip, so that the aluminum strip can wrap the plastic tube when it is bent upward. Then, the tubular aluminum strip is laser butt welded to form an aluminum strip reinforced tube on the surface of the core tube. The PVC-C core tube covered with the aluminum strip reinforced tube is heated by a high-frequency heating device 5. Then, a second PUR hot melt adhesive is applied to the surface of the aluminum strip through a second PUR gluing device. Then, the outer layer extrusion device 7 is used to apply the aluminum strip reinforced layer covered with adhesive. After cooling and shaping, the surface of the tube is corona treated and then marked to obtain the composite tube.

[0073] We produce DN20 x 2.0 mm pipes with a nominal pressure of PN1.6 MPa.

[0074] The core tube has an outer diameter of 17.4 mm, a thickness of 1.0 mm, a coating thickness of 0.2 mm, an aluminum strip thickness of 0.2 mm, a width of 59.95 mm, a punch size of 3 mm, 5 punches per row (width direction), a hole center distance of 9.07 mm from the outer layer thickness, a coating thickness of 0.2 mm, and an outer layer thickness of 0.8 mm.

[0075] Example 2

[0076] Unlike Example 1,

[0077] We produce DN50 x 4.5 mm pipes with a nominal pressure of PN1.0 MPa.

[0078] The core tube has an outer diameter of 45.4 mm, a core tube thickness of 2.5 mm, a first layer of adhesive coating thickness of 0.3 mm, an aluminum strip thickness of 0.3 mm, an aluminum strip width of 142.26 mm, an aluminum strip punch size of 4 mm, 10 punches per row (width direction), a hole center distance of 12.93 mm, an aluminum strip adhesive coating thickness of 0.3 mm, and an outer layer thickness of 1.5 mm.

[0079] Example 3

[0080] Unlike Example 1,

[0081] We produce pipes with a diameter of DN160x18.5mm and a nominal pressure of PN2.5MPa.

[0082] The core tube has an outer diameter of 145.0 mm, a thickness of 12.0 mm, a coating thickness of 0.5 mm, an aluminum strip thickness of 0.5 mm, a width of 151.05 mm, a punch size of 4 mm, 14 punches per row (width direction), a hole center distance of 30.32 mm, a coating thickness of 0.5 mm, and an outer layer thickness of 6.0 mm.

Claims

1. A method for preparing a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe, characterized in that, Includes the following steps: S1, Drilling: The aluminum strip is uncoiled in sequence and punched through the punching device (1) of the composite tube production equipment (105) to form hot melt adhesive penetration holes (103). Then, the surface of the aluminum strip is cleaned by the cleaning device (6) of the composite tube production equipment (105) to remove impurities. S2, trimming: The perforated aluminum strip is trimmed by the trimming device (2) of the composite pipe production equipment (105); S3, PVC-C core tube preparation: PVC-C raw materials are extruded into PVC-C core tubes using a twin-screw extruder; S4, Core tube coated with hot melt adhesive: PVC-C core tube is coated with solid reactive polyurethane hot melt adhesive. The hot melt adhesive is melted by the first PUR gluing device (3) of the composite tube production equipment (105) and injected into the co-extrusion mold through the nozzle to be evenly coated on the surface of the core tube. S5, Aluminum strip wrapped core tube: After trimming, the aluminum strip is passed through the forming device (4) of the composite tube production equipment (105) and the PVC-C core tube coated with hot melt adhesive is placed above the aluminum strip, so that the aluminum strip can wrap the plastic tube during the process of gradually bending into a tube shape. Then, the tubular aluminum strip is laser butt welded to form an aluminum strip reinforced tube on the surface of the core tube. S6, high frequency heating: The PVC-C core tube covered with aluminum strip reinforced tube is heated by high frequency heating device (5) of composite pipe production equipment (105), and then PUR hot melt adhesive is applied to the surface of aluminum strip again by the second PUR adhesive device (8) according to the adhesive principle of step S4. S7, Outer layer preparation: The PVC-C outer pipe is co-extruded and then extruded through the outer layer extrusion device (7) of the composite pipe production equipment (105) to form a composite pipe by covering the outer layer with the coated aluminum strip reinforcement layer. The composite pipe production equipment (105) includes a frame (10) and a punching device (1), a cleaning device (6), a trimming device (2), a forming device (4), a high-frequency heating device (5), a second PUR gluing device (8), an outer layer extrusion device (7), a twin-screw extrusion mechanism (9), and a first PUR gluing device (3) arranged on the frame (10). The punching device (1), the cleaning device (6), the trimming device (2), the forming device (4), the high-frequency heating device (5), and the second PUR gluing device (8) are arranged in sequence. The twin-screw extrusion mechanism (9) and the first PUR gluing device (3) are arranged in sequence and located to the right of the punching device (1). Both the first PUR coating device (3) and the second PUR coating device (8) include a screw extrusion mechanism (81). The extrusion port of the screw extrusion mechanism (81) is provided with a detachable uniform co-extrusion die (82). The detachable uniform co-extrusion die (82) includes a connecting pipe (821), an annular extrusion tube (822), a heating ring (823), an upper half heat preservation ring (824), and a lower half heat preservation ring (825). The heating ring (823) is located on the outside of the annular extrusion tube (822), and the connecting pipe (821) is located on both sides of the annular extrusion tube (822). The upper half heat preservation ring (824) is located on the outside of the annular extrusion tube (825). 4) The lower half insulation ring (825) is located on the outside of the connecting pipe (821). The heating ring (823) has semi-through grooves (826) on both sides. The annular extrusion tube (822) has limit posts (827) on both sides. One of the limit posts (827) is an inlet tube. The upper half insulation ring (824) and the lower half insulation ring (825) have fixing posts (828) on their inner sides. The connecting pipe (821) has a limit hole (829) that cooperates with the fixing post (828). The upper half insulation ring (824) and the lower half insulation ring (825) are connected by bolts. The annular extrusion tube (822) includes an annular tube body (820), the inner sidewall of the annular tube body (820) is provided with a plurality of glue outlet holes (830) along the circumferential direction, and the glue inlet tube is fixed on the outer sidewall of the annular tube body (820). The cleaning device (6) includes a housing (61), a cleaning brush roller (62), a vacuum adsorption roller (63), a dust suction pipe (64), a waste collection trough (65), and a support roller (66). The housing (61) has through holes (611) on both sides to facilitate the passage of aluminum strips. The cleaning brush roller (62) is located above the support roller (66) and is rotatably mounted on the side wall of the housing (61). The vacuum adsorption roller (63) is located behind the support roller (66) and is rotatably connected to the side wall of the housing (61). The waste collection trough (65) is located below the vacuum adsorption roller (63). The dust suction pipe (64) is located on the side of the cleaning brush roller (62) and extends to the outside of the housing (61). The vacuum adsorption roller (63) includes an outer roller (631) with a hollow interior and an inner roller (632) with a hollow interior. There is a cavity (633) between the outer roller (631) and the inner roller (632). The outer roller (631) and the inner roller (632) are coaxial. A suction hole (634) is provided on the side wall of the inner roller (632), and an adsorption hole (635) is provided on the outer roller (631). The waste collection tank (65) includes a tank body (651) with a top opening. A partition (652) is provided in the middle of the tank body (651). A waste inlet (654) is formed between the partition (652) and the side wall of the tank body (651). An upwardly inclined scraper (653) is provided on one side of the partition (652), and an air suction port (655) is provided at the bottom left side of the tank body (651).

2. The method for preparing a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe according to claim 1, characterized in that, The punching device (1) includes a worktable (11), a first guide wheel (12), a second guide wheel (13), and a laser (14). The first guide wheel (12) is located on the side of the worktable (11), the second guide wheel (13) is located on the upper surface of the worktable (11), and the laser (14) is located above the worktable (11). A waste trough (15) is provided on the worktable (11) relative to the laser (14).

3. The method for preparing a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe according to claim 1, characterized in that, The trimming device (2) includes two rotating rollers (21) that rotate relative to each other, a left waste collection roller (22), a left guide roller group (23), a right waste collection roller (24), and a right guide roller group (25). One of the rotating rollers (21) has a groove (211) on its roller surface along the circumferential direction, and the other rotating roller (21) has a protrusion (212) on its roller surface. The groove (211) and the protrusion (212) are positioned and matched in shape. A material feeding gap (26) is formed between the two rotating rollers (21). The left waste collection roller (22) and the left guide roller group (23) are located on the left side of the rotating roller (21), and the right waste collection roller (24) and the right guide roller group (25) are located on the right side of the rotating roller (21).

4. The method for preparing a porous aluminum strip butt-welded reinforced chlorinated polyvinyl chloride composite pipe according to claim 1, characterized in that, The forming device (4) includes a transition roller group (41), a pre-bending mechanism (42), a first shrink tube (43), a second shrink tube (44), a laser welding mechanism (45), and a weld position detection mechanism (46) arranged sequentially on the frame (10). The transition roller group (41) includes a left support plate (411), a right support plate (412), a left transition roller (413), and a right transition roller (414). The left support plate (411) and the right support plate (412) are fixed on the frame (10). A plurality of left transition rollers (413) are arranged in a rotatable linear array on the left support plate (411), and a plurality of right transition rollers (414) are arranged in a rotatable linear array on the right support plate (412). The laser welding mechanism (45) includes a slide rail (451) and a laser welding head (452) that slides left and right on the slide rail (451).

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