Twisted wrap-pultrusion bonding lap device and lap method for thermoplastic composite rods

Abstract

This invention proposes a torsion winding-extrusion bonding lap splicing device and method for thermoplastic composite reinforcement, belonging to the field of fiber-reinforced thermoplastic resin composite reinforcement connection technology. The device includes a reinforcement waveform forming device, a bidirectional torsion device, a lap diameter adjuster, a lap length adjuster, an upper mold, a lower mold, and a thermoplastic resin sleeve. The method includes: processing the reinforcement to be lapped into a continuous waveform using the reinforcement waveform forming device; using the bidirectional torsion device to perform reverse spiral winding of two waveform reinforcements to form a self-locking lap structure; and placing the thermoplastic resin sleeve into a molding cavity composed of upper and lower molds. This invention achieves dual enhancement of mechanical interlocking and resin interface bonding through the synergistic effect of waveform pre-shaping, bidirectional torsion self-locking, and hot-pressing consolidation. The entire process is free from damaging operations such as cutting and stranding, significantly improving the load-bearing capacity, stability, and construction efficiency of the lap joint, making it suitable for large-scale engineering applications of thermoplastic composite reinforcement.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fiber-reinforced thermoplastic resin (FRTP) composite bar connection in civil engineering, and particularly relates to a thermoplastic composite bar lapping device and lapping process with no damage, high strength and rapid forming achieved by adopting a waveform preforming-bidirectional torsional winding. BACKGROUND

[0002] In civil engineering structures in coastal, cross-sea, salt spray erosion and industrial corrosion environments, traditional steel bars have caused structure cracking, spalling and bearing capacity attenuation due to corrosion, which has become a core pain point restricting the service life of infrastructure. In order to fundamentally solve the safety hazards and high maintenance costs caused by steel bar corrosion, fiber-reinforced resin-based composite bars have gradually become an important direction to replace traditional steel bars due to their outstanding advantages of lightweight, high strength, excellent mechanical properties, fatigue resistance, corrosion resistance and the like, and have shown broad application prospects in marine engineering, bridge components and special concrete structures.

[0003] According to the type of resin matrix, fiber-reinforced resin composite materials can be divided into two types of thermosetting resin matrix and thermoplastic resin matrix. The current mainstream reinforced bars are mostly prepared by using thermosetting matrix resin, and after forming, a stable cross-linked structure is formed, which has high strength and stiffness. However, due to the limitation of the material itself, the fracture elongation rate of this type of bar is low, the impact resistance is weak, and brittle fracture and internal damage easily occur under impact load and repeated load; at the same time, the thermosetting material cannot be heated and softened for reshaping, the on-site processing adaptability is poor, the recycling difficulty is high, and it is difficult to meet the requirements of modern engineering for green building materials and recyclable construction. In addition, this type of bar is prone to interfacial debonding and stress transfer efficiency reduction under the action of complex stress and temperature and humidity coupling, which limits its use in key stress nodes and high toughness demand parts. In comparison, thermoplastic matrix composite bars have linear molecular chain structure, can realize reversible forming of heating softening and cooling solidification, and have the advantages of high toughness, impact resistance, corrosion resistance, repeatable processing and environmental protection and recycling, which can effectively make up for the performance short board of thermosetting bars, and are more suitable for the needs of on-site rapid connection, flexible construction and long-term safe service. As a new generation of high-performance structural reinforcing bar, the lapping quality directly affects the overall stress performance, load transfer efficiency and structure safety, and is a key technology to determine whether this type of material can be applied on a large scale.

[0004] At present, the lapping method of composite bars is mainly used in the scene of connecting the concrete members of fabricated structure and cast-in-place structure due to the length limitation of the bars. The mainstream technology is mainly designed around thermosetting bars, which is mainly divided into mechanical connection and adhesive bonding. Mechanical connection relies on metal sleeves, clamps and other anchoring methods, which can easily cause stress concentration, electrochemical corrosion, bar surface damage and other problems, and the long-term service reliability is insufficient. Adhesive bonding mainly uses thermosetting resin system, which has long curing time, low construction efficiency, and the interfacial bonding strength is significantly affected by the environment. It is easy to age and fail under high temperature and humidity conditions, and it cannot realize the molecular level fusion of the bar and the bonding medium.

[0005] For the melting lapping characteristics of thermoplastic composite bars, the existing equipment and technology have obvious deficiencies: manual lapping is difficult to stably control the key parameters such as temperature and pressure, and the lapping quality has large dispersion; special forming device is lacking, and batch preparation of test pieces with different diameters, different lapping lengths and different reinforcement forms cannot be realized; the lapping interface is mainly mechanical engagement, which is difficult to form a molecular chain interpenetrating structure, resulting in that the lapping strength and stability cannot meet the requirements of test and engineering. Therefore, it is of great significance to develop a special lapping device and forming method for thermoplastic composite bars, which integrates waveform preprocessing, bidirectional twisting and precise hot pressing forming functions, realizes reliable lapping with no damage, high strength and high efficiency, and adapts to multiple specifications, to improve the mechanical properties of lapping joints, meet the batch preparation requirements of test and engineering, and promote the large-scale application of thermoplastic composite bars in civil engineering field. SUMMARY

[0006] Therefore, in order to solve the problems of large quality dispersion, insufficient interfacial bonding strength and poor adaptability of the existing thermoplastic composite bar lapping process, the present application provides a twisting and wrapping-extrusion bonding lapping device and lapping method for thermoplastic composite bars. The forming method forms a spiral interlocking lapping structure for two bars to be connected through waveform pre-shaping and bidirectional twisting process, and then the lapping section is covered with a thermoplastic resin sleeve and placed in a forming mold. The whole hot pressing and curing forming is completed by means of a flat vulcanizing machine. The present application combines mechanical interlocking structure and high temperature melting crosslinking effect, relies on structural engagement constraint and resin interface fusion to realize double mechanical enhancement, significantly improves the bearing capacity and long-term service stability of the lapping joint, and the whole processing flow does not need to cut and split the fiber of the bar, which maximizes the original mechanical integrity of the substrate.

[0007] To achieve the above-mentioned purpose, the following technical scheme is adopted: a twisting and wrapping-extrusion bonding lapping device and lapping method for thermoplastic composites bars, comprising a thermoplastic resin sleeve, an upper mold, a lower mold, a bar waveform former, a bidirectional twister, a lapping diameter adjuster and a lapping length adjuster, The rib material wave former makes the corrugated fiber-reinforced thermoplastic resin composite rib into a continuous wave shape, and the rib surface forms a regular concave-convex occlusion structure, The bidirectional twister implements reverse spiral winding on the two corrugated fiber-reinforced thermoplastic resin composite ribs, so that a tightly self-locking lap joint structure is formed between the ribs. The upper die and the lower die are used in cooperation, the two corrugated fiber-reinforced thermoplastic resin composite ribs processed by the rib material wave former and the bidirectional twister are sleeved with a thermoplastic resin sleeve, and then the ribs and the thermoplastic resin sleeve are integrally placed in the molding cavity of the upper die and the lower die. The lap diameter adjuster and the lap length adjuster are detachably installed in the molding cavity, the lap diameter adjuster is used to adjust the cavity diameter to adapt to ribs of different diameters, and the lap length adjuster 10 is used to adjust the cavity length to adapt to different lap lengths.

[0008] Preferably, a limiting cylinder is arranged on the lower die, and a positioning hole is arranged on the upper die, and the positioning hole is used in cooperation with the limiting cylinder to complete die positioning.

[0009] Preferably, the thermoplastic resin sleeve sleeved outside the lap section is molten and mutually soluble with the rib matrix in a high-temperature hot-pressing environment, sufficiently fills the wave gap and the twisted gap, and forms an integrated fusion interface.

[0010] Preferably, the wave shape of the corrugated fiber-reinforced thermoplastic resin composite rib is a sine wave or a cosine wave, the wave amplitude is 4-6 mm, and the wavelength is 18-25 mm.

[0011] Preferably, the twisting density of the bidirectional twister is 2.5-4 turns per 100 mm.

[0012] Preferably, the cross-sectional shape of the molding cavity of the upper die and the lower die matches the outer shape of the lap joint to be formed, the lap diameter adjuster is an annular gasket or an arc-shaped lining plate of different thicknesses, and the lap length adjuster is a stop block of different lengths.

[0013] A lap joint method of a twisted winding-extrusion bonding lap joint device for thermoplastic composite ribs, comprising the following steps: S1: wave preprocessing: processing two thermoplastic composite ribs to be lap jointed into a continuous wave shape by a rib material wave former to obtain corrugated fiber-reinforced thermoplastic resin composite ribs; S2: bidirectional twisting lap joint: placing the two corrugated fiber-reinforced thermoplastic resin composite ribs in a bidirectional twister to implement reverse spiral winding and form a spiral interlaced lap joint structure; S3: sleeve sleeving: sleeving a thermoplastic resin sleeve outside the spiral interlaced lap joint structure; S4: mold assembly: according to the diameter of the reinforcing material and the preset lap length, select the appropriate lap diameter adjuster 9 and lap length adjuster installed in the forming cavity of the lower mold, put the lap structure with the thermoplastic resin sleeve into the cavity, cover the upper mold, and complete the mold assembly; S5: hot pressing and curing: place the assembled mold on the workbench of the flat vulcanizing machine, heat to the melting temperature of the thermoplastic resin, apply a preset pressure and keep warm, and then cool and keep pressure until the resin is cured; S6: demolding and taking out: after unpressurizing, open the mold and take out the formed lap specimen.

[0014] Preferably, in step S5, the heating temperature is the melting softening temperature of the thermoplastic resin matrix, the applied pressure is 12-18 MPa, and the warm-keeping and pressure-keeping time is 4-6 min.

[0015] Preferably, the material of the thermoplastic resin sleeve is the same as or compatible with the material of the matrix resin of the thermoplastic composite rod.

[0016] Preferably, the thermoplastic composite rod is a carbon fiber reinforced nylon composite rod, a glass fiber reinforced polypropylene composite rod, or a basalt fiber reinforced polyacrylate composite rod.

[0017] Compared with the prior art, the device and method for hot-pressing and curing of the thermoplastic composite rod have the following advantages: 1. The device and method of the present application realize the dual enhancement of mechanical embedding and resin interface bonding of the composite rod lap joint node through the synergistic effect of wave-shaped pre-shaping, bidirectional torsion self-locking and hot-pressing and curing, and have the advantages of non-damage processing, high strength bearing, high universality and high stability, effectively solving the problems of large quality dispersion, insufficient interface bonding strength and poor adaptability of the existing thermoplastic composite rod lap joint process, and meeting the reliable connection requirements of civil engineering test preparation and engineering application.

[0018] 2. The lap joint process of the present application does not perform damage operations such as cutting, stock splitting and splitting on the reinforcing material throughout the process, maximally retains the continuity of the fibers and the integrity of the matrix, fundamentally avoids the weakening of the mechanical properties of the reinforcing material by the traditional lap joint method, and realizes truly damage-free connection.

[0019] 3. The present application can be adapted to different specifications and surface configurations of composite rods to carry out lap joint operations, and has a wide range of applications. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of the present application, are used to provide a further understanding of the present application, and the illustrative embodiments thereof and their descriptions serve to explain the present application, and do not constitute an improper limitation thereof. In the drawings: Figure 1The schematic diagram of the overall structure of the torsion winding-extrusion bonding lap forming device for the fiber reinforced thermoplastic resin composite rod of the present application; Figure 2 The schematic diagram of the front structure of the torsion winding-extrusion bonding lap forming device for the fiber reinforced thermoplastic resin composite rod of the present application; Figure 3 The schematic diagram of the side structure of the torsion winding-extrusion bonding lap forming device for the fiber reinforced thermoplastic resin composite rod of the present application; Figure 4 The schematic diagram of the three-dimensional structure of the upper die before the die is closed of the present application; Figure 5 The schematic diagram of the top view structure of the upper die before the die is closed of the present application; Figure 6 The schematic diagram of the three-dimensional structure of the upper die after the die is closed of the present application; Figure 7 The schematic diagram of the three-dimensional structure of the lap diameter adjuster of the present application; Figure 8 The schematic diagram of the three-dimensional structure of the lap length adjuster of the present application; Figure 9 The schematic diagram of the three-dimensional structure of the bidirectional twister of the present application; Figure 10 The schematic diagram of the standard sine wave lap process provided by the present application; The reference signs are explained as follows: 1 - corrugated fiber reinforced thermoplastic resin composite rod; 2 - thermoplastic resin sleeve; 3 - upper die; 4 - lower die; 5 - flat vulcanizing machine; 6 - limiting cylinder; 7 - rod material wave former; 8 - bidirectional twister; 9 - lap diameter adjuster; 10 - lap length adjuster DETAILED DESCRIPTION The present application will be further described in conjunction with the drawings and specific embodiments. It can be understood that the specific embodiments described herein are only for the purpose of explaining the present application, but not for limiting the present application. In addition, it should be noted that only the parts related to the present application are shown in the drawings for the purpose of description, and all the technical and scientific terms used herein have the same meanings as understood by the persons skilled in the art of the present application, unless otherwise defined. The terms used herein are only for the purpose of describing the specific embodiments, and are not intended to limit the present application.

[0021] Reference is made to Figures 1-10 In the present embodiment, a torsion winding-extrusion bonding lap device for a thermoplastic composite rod is provided, which takes wave preforming and bidirectional twister self-locking as the core, and the whole includes a thermoplastic resin sleeve 2, an upper die 3, a lower die 4, a limiting cylinder 6, a rod material wave former 7, a bidirectional twister 8, a lap diameter adjuster 9, and a lap length adjuster 10. The corrugated fiber-reinforced thermoplastic resin composite material rib 1 is formed into a continuous corrugated shape by the rib corrugator 7, so that the surface of the rib forms a regular concave-convex interlocking structure, providing a reliable mechanical interlocking foundation for subsequent lap splicing, and effectively improving the anti-slip and anti-pull-out ability of the lap splice. Two corrugated fiber-reinforced thermoplastic resin composite ribs 1 are wound in reverse spirals using a bidirectional torsion bar 8, forming a tight, self-locking lap joint structure between the ribs. This structure maintains a stable shape without the need for additional fasteners, significantly improving the overall stiffness and stress uniformity of the joint. The lap joint relies on the mechanical interlocking and friction between the ribs combined with the adhesive effect of the resin interface to synergistically transmit force, resulting in excellent comprehensive mechanical properties. The upper mold 3 and the lower mold 4 are used together. Two corrugated fiber-reinforced thermoplastic resin composite material ribs 1, which have been processed by the rib corrugation forming device 7 and the bidirectional torsion device 8, are covered with thermoplastic resin sleeves 2. Then the ribs and thermoplastic resin sleeves 2 are placed as a whole in the molding cavity of the upper mold 3 and the lower mold 4. The overlap diameter adjuster 9 and the overlap length adjuster 10 are detachably installed in the molding cavity. The overlap diameter adjuster 9 is used to adjust the cavity diameter to accommodate ribs of different diameters, and the overlap length adjuster 10 is used to adjust the cavity length to accommodate different overlap lengths.

[0022] The lap splicing process avoids any damaging operations such as cutting, stranding, or splitting the reinforcing bars, preserving the fiber continuity and matrix integrity to the greatest extent possible. This fundamentally avoids the weakening of the mechanical properties of the reinforcing bars caused by traditional lap splicing methods, achieving a truly non-destructive connection.

[0023] The thermoplastic resin sleeve 2, which is fitted on the outer side of the lap section, melts and dissolves with the reinforcing material matrix under high temperature and hot pressing environment, fully filling the corrugated gaps and torsional gaps to form an integrated fusion interface, which significantly improves the joint strength, density and long-term durability.

[0024] The device is equipped with an overlap diameter adjuster 9 and an overlap length adjuster 10, which can be quickly replaced and combined to change the size of the molding cavity. One set of molds can be adapted to the preparation of specimens with various rib diameters and overlap lengths, greatly improving the testing efficiency and equipment versatility.

[0025] Selection and usage of the diameter adjuster 9: Based on the nominal diameter of the reinforcing material used in the experiment, select the corresponding lap diameter adjuster 9; the internal opening of the adjuster is precisely matched with the outer diameter of the reinforcing material to limit the radial space inside the mold cavity, ensuring that the sleeve 2 and the reinforcing material 1 fit together, and avoiding problems such as interface debonding and insufficient density caused by excessively large / small molding gap.

[0026] Selection and usage of the length adjuster 10: Based on the designed overlap length, an overlap length adjuster 10 of the corresponding specification was selected. The adjuster is a segmented stop structure used to limit the length of the axial overlap area inside the mold, precisely controlling the effective overlap section size of the molten interface. Both adjusters serve to limit the movement of the reinforcing material. The lower mold 4 is provided with a limiting cylinder 6, and the upper mold 3 is provided with a positioning hole. The positioning hole and the limiting cylinder 6 are used together to complete the mold positioning. The mold achieves precise coaxial alignment of the upper and lower molds through the limiting cylinder 6. Combined with the segmented temperature control and segmented pressure control molding process of the flat vulcanizing machine 5, it ensures that the reinforcing bar does not shift, twist, or become eccentric during the heating and pressurization process, thus ensuring stable joint performance and high test repeatability.

[0027] Specific assembly steps for the torsion winding-extrusion bonding lap splice device for thermoplastic composite reinforcement: Step 1: First, fix the limiting cylinder 6 in the positioning hole of the lower mold 4 and weld it in place; Step 2: Calibrate the rib waveform forming device 7, the bidirectional torsion device 8, and the various size adjustment components according to the preset process parameters; Step 3: The upper mold 3 is precisely aligned with the limiting cylinder 6 through the circular hole groove to achieve closed assembly of the upper and lower molds; Step 4: Place the assembled tooling in the center on the worktable of the flat vulcanizing machine 5 to complete the assembly of the entire overlapping device.

[0028] The overlapping process using the overlapping device of the present invention is as follows: Step 1: First, preheat the flat vulcanizing machine 5 to the specified process temperature. Then, process the straight ribs into a continuous sine or cosine corrugated shape using the rib corrugator 7. Next, use the bidirectional torsion mechanism 8 to rotate the two corrugated ribs relative to each other to construct a spiral interlocking structure. Finally, install the thermoplastic resin sleeve 2 on the outside of the interlocking section. Step 2: Select and match the appropriate diameter adjustment component 9 and length adjuster 10 according to the requirements of specimen production. After installing them in the corresponding cavity position of the lower mold 4, insert the pre-treated corrugated composite material rib 1 component; align the positioning groove of the upper mold 3 with the positioning and limiting cylinder 6 of the lower mold 4 and close it smoothly to ensure that the limiting structure is fully fitted and aligned; place the assembled mold tool in the center of the flat vulcanizing machine 5, fit the mold surface and continue to heat it. Step 3: After the overall temperature of the mold reaches the set threshold, apply constant mold closing pressure and maintain it under constant temperature and pressure conditions for a preset time. Then, switch to the cooling and pressure stabilization stage until the sleeve resin is completely solidified and formed. Step 4: After depressurizing the equipment and waiting for the mold to cool to room temperature, disassemble the mold components and take out the molded specimen; open the upper mold 3, take out the processed rib lap joint component, and complete all lap joint operations, thus achieving high-strength, damage-free self-locking lap joint.

[0029] The core of the technical solution of this invention lies in: This device integrates a single-unit operating structure encompassing waveform pre-compression molding, bidirectional torsion interlocking, and high-temperature molding consolidation. Combined with an adaptive adjustable mold assembly, it enables standardized, integrated molding of multi-specification composite material lap joint specimens. This lap joint process employs a novel, non-destructive method combining waveform modification and bidirectional torsion self-locking. By constructing a twisted, interlocking structure for the reinforcing bars, it enhances mechanical force transmission efficiency. Simultaneously, by leveraging the diffusion and fusion characteristics of resin molecular chains under hot pressing, it forms a dual-stress system of mechanical interlocking and interfacial adhesion, fundamentally improving the overall mechanical stability of the lap joint. This mold structure abandons the traditional reinforcing bar stranding process, relying on a dedicated torsion-locking molding structure to achieve non-destructive lap jointing of the reinforcing bars. Equipped with a detachable size adjustment component, it can precisely adapt to various molding process parameters, meeting the diverse application needs of industrial production and experimental preparation.

[0030] Example 1 The standard sinusoidal waveform lap splice (16mm diameter, 200mm lap length) for carbon fiber reinforced nylon composite reinforcement is implemented as follows: First, preheat the flat vulcanizing machine to the temperature required for melting and softening thermoplastic resin. Using a rib waveform forming device, press two carbon fiber reinforced nylon (CF / PA6) composite ribs to be overlapped into a continuous sinusoidal waveform with an amplitude of 5mm and a wavelength of 20mm. Place the two waveform ribs into a bidirectional torsion device and twist them relative to each other at a torsion density of 3 turns / 100mm to form a stable twisted overlapping structure. A thermoplastic resin sleeve of equal length is then fitted over the overlapping section. In this embodiment, a standard mold cavity is used: an overlap length of 200mm and a diameter of 23mm, eliminating the need for overlap diameter and overlap length adjusters. The pre-treated ribs are smoothly placed into the corresponding slot in the lower mold. The upper mold is closed, ensuring precise alignment and engagement between the upper mold limiting hole and the lower mold limiting cylinder. The assembled mold is placed at the center of the working surface of the flat vulcanizing machine. The mold is closed until it lightly touches the upper mold surface on the upper platen, and continuous heating is maintained until the mold reaches the set temperature. Then, a molding pressure of 15 MPa is applied, and the mixture is held at this temperature and pressure for 5 minutes to allow the resin to fully melt and penetrate, forming an interpenetrating molecular chain structure. After completion, the mixture enters a cooling and pressure holding stage until the resin cures. The pressure is then released, the mold is opened, and the overlapped composite reinforcement is removed, thus completing the standard sinusoidal waveform overlap without adjuster.

[0031] Example 2 The specific implementation method for short lap splices (12mm diameter, 100mm lap length) of glass fiber reinforced polypropylene composite reinforcement bars with a cosine waveform is as follows: Preheat the flat vulcanizing machine to the set temperature for the overlapping process. Use a rib waveform forming device to process two glass fiber reinforced polypropylene (GF / PP) composite ribs into a continuous cosine waveform with an amplitude of 4 mm and a wavelength of 25 mm. Insert the waveform ribs into a bidirectional torsion device and twist them relative to each other at a torsion parameter of 2.5 turns / 100 mm to form a twisted structure. The overlapping section is then fitted with a thermoplastic resin sleeve. A 100 mm long overlap length adjuster is pre-installed in the lower mold slot to meet the requirements for preparing short overlap length specimens. The pre-treated ribs are then placed into the slot. The mold is closed and the limiting cylinders are aligned. The mold is placed in the central area of ​​the vulcanizing machine for preheating. Once the mold temperature reaches the set value uniformly, a pressure of 12 MPa is applied and held for 6 minutes. The temperature is then lowered and the pressure is maintained until the resin is completely cured. The pressure is released and the mold is opened to obtain a short-length cosine waveform overlap specimen.

[0032] Example 3 The specific implementation method for high torsional density reinforced lap splices (diameter 20mm, lap length 200mm) of basalt fiber reinforced polyacrylate composite reinforcement is as follows: Preheat the flat vulcanizing machine to the upper limit of the process temperature. Use a rib corrugated forming device to process the basalt fiber reinforced polyacrylate (BF / PA) composite ribs into a large-amplitude sinusoidal waveform with an amplitude of 6 mm and a wavelength of 18 mm. Place the corrugated ribs into a bidirectional torsion device and torsion them relative to each other at a high torsion density of 4 turns / 100 mm to form a tight twisted interlocking structure. Cover the torsion lap section with a thermoplastic resin sleeve, and then wrap continuous fiber cloth circumferentially around the outer layer of the sleeve to achieve further mechanical reinforcement. In this embodiment, a standard 200 mm lap length slot is used, and the lap length adjuster is not used. The lap diameter adjuster corresponding to the thickness is selected according to the actual diameter of the ribs. After the ribs are placed and the mold is closed and aligned, place the mold into the vulcanizing machine for preheating. After the temperature reaches the preset value, apply a high pressure of 18 MPa and hold for 4 minutes to allow the resin to melt rapidly and form a stable bond with the ribs and fiber cloth. Then, cool down and hold the pressure until fully cured, release the pressure and open the mold to obtain a high-mechanical-performance reinforced lap joint specimen.

[0033] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement, characterized in that: It includes a thermoplastic resin sleeve (2), an upper mold (3), a lower mold (4), a rib corrugated forming device (7), a bidirectional torsion device (8), an overlap diameter adjuster (9), and an overlap length adjuster (10). The corrugated fiber reinforced thermoplastic resin composite material reinforcement (1) is formed into a continuous corrugated shape, so that a regular interlocking structure is formed on the surface of the reinforcement. The bidirectional torsion device (8) performs reverse spiral winding on the two corrugated fiber-reinforced thermoplastic resin composite ribs (1), so that a tight self-locking lap structure is formed between the ribs. The upper mold (3) and lower mold (4) are used together. Two corrugated fiber-reinforced thermoplastic resin composite ribs (1) that have been processed by the rib corrugated forming device (7) and the bidirectional torsion device (8) are covered with thermoplastic resin sleeves (2). Then the ribs and thermoplastic resin sleeves (2) are placed together in the forming cavity of the upper mold (3) and lower mold (4). The overlap diameter adjuster (9) and overlap length adjuster (10) are detachably installed in the molding cavity. The overlap diameter adjuster (9) is used to adjust the cavity diameter to accommodate ribs of different diameters, and the overlap length adjuster (10) is used to adjust the cavity length to accommodate different overlap lengths.

2. The torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement according to claim 1, characterized in that: The lower mold (4) is provided with a limiting cylinder (6), and the upper mold (3) is provided with a positioning hole. The positioning hole and the limiting cylinder (6) are used together to complete the mold positioning.

3. The torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement according to claim 1, characterized in that: The thermoplastic resin sleeve (2) fitted on the outer side of the overlapping section melts and dissolves with the reinforcing material matrix under high temperature and hot pressing environment, fully filling the corrugated gap and torsion gap to form an integrated fusion interface.

4. The torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement according to claim 1, characterized in that: The waveform of the corrugated fiber-reinforced thermoplastic resin composite material rib (1) is a sine wave or a cosine wave, with an amplitude of 4-6 mm and a wavelength of 18-25 mm.

5. The torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement according to claim 1, characterized in that: The torsion density of the bidirectional torsion device (8) is 2.5-4 turns / 100mm.

6. The torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement according to claim 1, characterized in that: The cross-sectional shape of the forming cavity of the upper mold (3) and the lower mold (4) matches the shape of the lap joint to be formed. The lap diameter adjuster (9) is an annular gasket or arc-shaped liner of different thicknesses, and the lap length adjuster (10) is a stop block of different lengths.

7. A method for splicing a torsion winding-extrusion bonding splice device for thermoplastic composite reinforcement as described in any one of claims 1-6, characterized in that: Includes the following steps: S1: Waveform preprocessing: The two thermoplastic composite ribs to be overlapped are processed into a continuous corrugated shape by a rib waveform forming machine (7) to obtain a corrugated fiber-reinforced thermoplastic resin composite rib (1). S2: Bidirectional torsion lap: Two corrugated fiber reinforced thermoplastic resin composite ribs (1) are placed in a bidirectional torsion device (8) and reverse spiral winding is performed to form a spiral interlaced lap structure. S3: Sleeve assembly: A thermoplastic resin sleeve (2) is installed on the outside of the spiral interlocking lap structure; S4: Mold assembly: According to the diameter of the reinforcing bar and the preset overlap length, select the appropriate overlap diameter adjuster (9) and overlap length adjuster (10) and install them in the molding cavity of the lower mold (4). Place the overlap structure with the thermoplastic resin sleeve (2) in the cavity, cover it with the upper mold (3), and complete the mold assembly. S5: Hot pressing curing: Place the assembled mold on the worktable of the flat vulcanizing machine (5), heat it to the melting temperature of the thermoplastic resin, apply the preset pressure and keep it warm and pressurized, and then cool down and keep it pressurized until the resin is cured; S6: Demolding and Part Removal: After depressurization, open the mold and remove the formed overlapping test piece.

8. The torsion winding-extrusion bonding lap splice device for thermoplastic composite reinforcement according to claim 7, characterized in that: In step S5, the heating temperature is the melting and softening temperature of the thermoplastic resin matrix, the applied pressure is 12-18 MPa, and the holding time is 4-6 min.

9. The torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement according to claim 7, characterized in that: The thermoplastic resin sleeve (2) is made of the same or compatible material as the matrix resin of the thermoplastic composite material rib.

10. The torsion winding-extrusion bonding lap splicing device for thermoplastic composite reinforcement according to claim 7, characterized in that: The thermoplastic composite reinforcement is carbon fiber reinforced nylon composite reinforcement, glass fiber reinforced polypropylene composite reinforcement, or basalt fiber reinforced polyacrylate composite reinforcement.

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