Thermal shrinkage belt type quick connection method for high-strength steel belt double-wall corrugated pipe

Abstract

The invention relates to the technical field of pipeline connection, and discloses a thermal shrinkage belt type quick connection method of a high-strength steel belt double-wall corrugated pipe, which comprises the following steps: pretreatment, connecting liquid preparation, connecting liquid coating, thermal shrinkage belt wrapping, thermal shrinkage treatment and curing cooling. Through systematic degreasing, coarsening and drying pretreatment on the pipeline connecting end part, surface pollutants are removed, proper roughness is formed, a clean substrate with a good anchoring effect is provided for subsequent bonding, the problem of weak bonding caused by interface pollution and microdefects is solved, and the service life of the pipeline connecting end part is prolonged. The base firmness and consistency of a connection interface are improved, the reliability of connection quality is guaranteed, the specially-made connection liquid is fully fused and combined with hot melt adhesive on the inner layer of the heat-shrinkable tape in the heat-shrinkable process, physical sealing can be achieved, tough chemical bonding and mechanical interlocking can be formed on the interface, and the service life of the heat-shrinkable tape is prolonged. Therefore, the long-term durability and stability of the sealing interface under complex working conditions are ensured.

Description

Technical Field

[0001] This invention relates to the field of pipe connection technology, specifically to a heat-shrinkable tape-based quick connection method for high-strength steel strip double-wall corrugated pipes. Background Technology

[0002] With the acceleration of urbanization, the scale of municipal infrastructure construction continues to expand. As a crucial component of urban construction, drainage pipeline engineering has garnered significant attention for its construction quality and efficiency. Steel-reinforced double-wall corrugated pipes, with their advantages of high strength, corrosion resistance, and large drainage capacity, have been widely used in drainage pipeline projects. Heat-shrink tape quick-connect technology, as a novel pipe connection process, demonstrates unique advantages in addressing construction challenges in areas with large temperature differences. Its core principle utilizes the thermal shrinkage properties of heat-shrink tape to maintain stable shrinkage stress under varying temperature conditions.

[0003] Currently, in the heat shrinkable tape connection process of high-strength steel strip double-wall corrugated pipes, the interfacial bonding between the heat shrinkable tape and the plastic surface of the pipe and the steel strip reinforcement mainly relies on the hot melt physical adhesion of hot melt adhesive. This bonding mechanism is prone to creep or stress relaxation under the long-term action of complex stress and media, which will lead to the gradual failure of the sealing interface and cause media leakage. At the same time, the existing process is highly dependent on the degree of pretreatment and cleanliness of the pipe connection end face. When there are invisible grease, moisture or micro-defects on the surface, it will directly weaken the bonding foundation. However, the lack of online monitoring and real-time compensation methods for such hidden defects during construction results in a large dispersion of connection quality, making it difficult to ensure long-term reliable sealing of the joint.

[0004] Therefore, a heat-shrinkable tape quick-connect method for high-strength steel strip double-wall corrugated pipes is proposed to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a heat-shrinkable tape-based quick connection method for high-strength steel strip double-wall corrugated pipes, which solves the problems mentioned in the background technology, such as the gradual failure of the sealing interface leading to media leakage and the large dispersion of connection quality, making it difficult to ensure long-term reliable sealing of the joint.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a heat-shrinkable tape quick-connect method for high-strength steel strip double-wall corrugated pipes, comprising the following steps: Step 1: Pretreatment, surface treatment of the connecting ends of the steel strip double-wall corrugated pipe, including degreasing, roughening and drying; Step 2: Preparation of the bonding fluid, which consists of adhesive resin, reinforcing agent and functional filler; Step 3: Applying the connecting fluid, uniformly applying the connecting fluid to the pretreated pipe end surface; Step 4: Wrap with heat shrink tape. Spiral-wrap or loop the heat shrink tape around the end of the pipe coated with the bonding fluid, ensuring that the bonding area is covered. Step 5: Heat shrinking treatment. A heating device is used to heat and shrink the heat shrink tape, so that the bonding liquid melts and adheres to the heat shrink tape. Step Six: Curing and Cooling. Natural cooling or forced air cooling will allow the joint to cure and form a high-strength sealed connection.

[0007] The steel-reinforced double-wall corrugated pipe is made of high-density polyethylene and steel strip composite structure, with a pipe diameter range of 200-1000mm and a wall thickness of 2-5mm. The heat shrinkable tape is made of radiation cross-linked polyethylene substrate with an internal hot melt adhesive layer, a thickness of 1.0-2.0mm and a width of 100-300mm. The heating device is an infrared heater, a hot air gun or a flame torch, with a heating temperature of 120-200℃.

[0008] Preferably, the pretreatment in step one includes the following steps: immersing the pipe connection end in a stainless steel tank of degreasing solution at room temperature for 0.5-1.5 hours, stirring with a mechanical stirrer at 50-150 r / min during the immersion process to remove surface oil and oxides; rinsing with a high-pressure water gun at 5-15 MPa pressure for 5-15 minutes to remove residual degreasing solution; then drying in an oven at 60-80℃ for 0.5-1 hour, or air-drying naturally for 2-4 hours, so that the surface moisture content is less than 5%; the roughening treatment uses a sandblasting machine or sandpaper to polish the surface roughness Ra to 3.2-6.3 μm.

[0009] Preferably, the degreasing solution is composed of the following components in the following mass ratio: 60-70 parts ethanol, 10-20 parts acetone, 5-10 parts organosilicon coupling agent, 2-5 parts surfactant, and 10-20 parts deionized water, wherein the ethanol concentration is 95%-99%, the acetone purity is ≥99%, the organosilicon coupling agent is one of γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane, and the surfactant is sodium dodecylbenzenesulfonate or polyoxyethylene ether. The degreasing solution is prepared by adding ethanol, acetone, and deionized water to a stirring device and stirring at 200-500 r / min for 10-20 min at 20-30℃, then adding the organosilicon coupling agent and surfactant, and stirring at 500-1000 r / min for 20-40 min to form a homogeneous solution.

[0010] Preferably, the connecting liquid in step two is made from the following raw materials in parts by weight: 50-60 parts isocyanate resin, 20-30 parts epoxy resin, 10-15 parts silane-modified polymer, 5-10 parts functional additives, 2-5 parts antioxidants, and 10-20 parts solvent, wherein the isocyanate resin is diphenylmethane diisocyanate or toluene diisocyanate, the epoxy resin is bisphenol A type epoxy resin, the silane-modified polymer is silane-modified polyether or silane-modified polyurethane, the functional additives are plasma-treated ceramic micropowder or carbon nanotubes, the antioxidants are hindered phenols or phosphites, and the solvent is xylene or ethyl acetate; the solid content of the connecting liquid is 40%-60%, and the viscosity range is [missing information]. .

[0011] Preferably, the preparation method of the connecting liquid includes: adding isocyanate resin and epoxy resin into a temperature-controlled reactor, controlling the temperature at 25-35°C, stirring at 300-600 r / min for 15-25 min to prepolymerize the resin, adding silane-modified polymer, continuing to stir for 10-20 min, then adding solvent and antioxidant, stirring at 500-800 r / min for 15-30 min, finally adding functional additives, increasing the speed to 800-1200 r / min and stirring for 30-50 min until uniformly mixed, filtering and storing in a sealed container, with a shelf life of no more than 7 days.

[0012] Preferably, the functional additive is prepared by the following method: industrial waste ceramics or glass fibers are collected, sorted, and then soaked in a pickling tank with a 5%-10% hydrochloric acid solution for 1-2 hours. The mixture is then rinsed with deionized water until neutral, dried in an oven at 80-100℃ for 2-3 hours, crushed and ground using a ball mill, and sieved to obtain ceramic microparticles with a particle size of 50-100 μm. The ceramic microparticles are then spread evenly in a plasma treatment chamber, and a vacuum is drawn to a pressure... to At Pa, nitrogen or argon gas is introduced at a flow rate of 20-60 sccm, followed by treatment with a plasma generator at a power of 400-800W for 10-20 minutes.

[0013] Preferably, the bonding fluid coating in step three includes: uniformly spraying the bonding fluid onto the end surface of the pipe using a spraying device or an airless spray gun, with a spraying pressure of 0.3-0.6 MPa, a spraying speed of 10-20 cm / s, and a coating thickness of 0.1-0.3 mm. After coating, the area is left to stand at room temperature for 5-15 minutes, and then the coated area is placed in an environment of 60-80℃ for 2-5 minutes. The ambient temperature of the coating operation is controlled at 15-30℃, and the ambient humidity is below 70%.

[0014] Preferably, in step four, the heat shrinkable tape wrapping process involves an overlap rate of 50%-60% to ensure no air bubbles or wrinkles. The hot melt adhesive embedded in the heat shrinkable tape is an ethylene-vinyl acetate copolymer or a polyamide hot melt adhesive with a melt index of 10-30 g / 10 min. Before wrapping, the heat shrinkable tape needs to be preheated at 40-60°C for 1-2 min. After wrapping, the tape is rolled with a pressure roller to remove air at a pressure of 0.1-0.3 MPa.

[0015] Preferably, in step five, the heat shrinking process, the heating device moves uniformly along the circumference of the heat shrinkable tape, the heating time is 3-10 minutes, and the temperature gradient is controlled as follows: initial preheating at 100-120℃ for 1-2 minutes, then raising to 150-180℃ for main shrinking for 2-5 minutes, and finally holding at 120-140℃ for 1-3 minutes to allow the hot melt adhesive to flow fully. The heating distance is 10-20 cm. After heat shrinking, the volume resistivity at the joint is not lower than [value missing]. The sealing pressure shall not be less than 0.5 MPa.

[0016] Preferably, in step six, during the curing and cooling process, the joint can be left to stand in a natural environment for 2-4 hours to allow it to cool and solidify naturally, or a forced air cooling device can be used to accelerate the cooling at a wind speed of 5-10 m / s for 0.5-1 hours to reduce the temperature of the joint to below 40°C. After curing, the joint is visually inspected to confirm that the surface of the heat shrink tape is flat, the hot melt adhesive is evenly overflowing, and there are no visible defects before the subsequent trench backfilling construction can proceed.

[0017] Compared with the prior art, the present invention provides a heat-shrinkable tape-based quick connection method for high-strength steel strip double-wall corrugated pipes, which has the following beneficial effects: 1. In this invention, by systematically degreasing, roughening and drying the pipe connection ends, surface contaminants are removed and a suitable roughness is formed, providing a clean substrate with good anchoring effect for subsequent bonding. This solves the problem of weak bonding caused by interface contamination and micro-defects, improves the basic firmness and consistency of the connection interface, and ensures the reliability of the connection quality.

[0018] 2. In this invention, by applying a specially formulated connecting liquid, it is fully melted and combined with the hot melt adhesive inside the heat-shrinkable tape during the heat shrinking process. This not only achieves physical sealing but also forms a strong chemical bond and mechanical interlock at the interface, enhancing the connection joint's ability to resist creep and stress relaxation under long-term loads. This ensures the long-term durability and stability of the sealed interface under complex working conditions.

[0019] 3. In this invention, by optimizing the wrapping process of the heat shrink tape and controlling the temperature curve of the heat shrink treatment, the heat shrink tape is uniformly heated and shrunk, and the hot melt adhesive is fully flowed and wetted. Combined with the controlled curing and cooling process, the joints are made into a dense and stable structure to resist external mechanical stress and temperature difference changes, ensuring the uniform and reliable performance of the joint and broadening the construction adaptability. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: A method for quick connection of high-strength steel strip double-wall corrugated pipe using heat-shrinkable tape, comprising the following steps: Step 1: Pretreatment, surface treatment of the connecting ends of the steel strip double-wall corrugated pipe, including degreasing, roughening and drying; Step 2: Preparation of the bonding fluid, which consists of adhesive resin, reinforcing agent and functional filler; Step 3: Applying the connecting fluid, uniformly applying the connecting fluid to the pretreated pipe end surface; Step 4: Wrap with heat shrink tape. Spiral-wrap or loop the heat shrink tape around the end of the pipe coated with the bonding fluid, ensuring that the bonding area is covered. Step 5: Heat shrinking treatment. A heating device is used to heat and shrink the heat shrink tape, so that the bonding liquid melts and adheres to the heat shrink tape. Step Six: Curing and Cooling. Natural cooling or forced air cooling will allow the joint to cure and form a high-strength sealed connection.

[0022] The steel-reinforced double-wall corrugated pipe is made of high-density polyethylene and steel strip composite structure. The pipe diameter range is 200mm, the wall thickness is 2mm, the heat shrink tape is radiation cross-linked polyethylene substrate, with built-in hot melt adhesive layer, thickness is 1.0mm, width is 100mm, and the heating device is infrared heater, hot air gun or flame torch, with a heating temperature of 120℃.

[0023] The pretreatment in step one includes the following steps: immerse the pipe connection end in a stainless steel tank of degreasing solution at room temperature for 0.5 hours. During the immersion process, use a mechanical stirrer at 50 r / min to stir and remove surface oil and oxides. After removal, rinse with a high-pressure water gun at 5 MPa pressure for 5 minutes to remove residual degreasing solution. Then place it in an oven at 60℃ for 0.5 hours or air dry for 2 hours to reduce the surface moisture content to below 5%. The roughening treatment uses a sandblasting machine or sandpaper to polish the surface to a roughness Ra of 3.2 μm.

[0024] The degreasing solution is composed of the following components in the following mass ratio: 60 parts ethanol, 10 parts acetone, 5 parts organosilicon coupling agent, 2 parts surfactant, and 10 parts deionized water. The ethanol concentration is 95%, the acetone purity is ≥99%, the organosilicon coupling agent is γ-aminopropyltriethoxysilane, and the surfactant is sodium dodecylbenzenesulfonate or polyoxyethylene ether. The degreasing solution is prepared by adding ethanol, acetone, and deionized water to a stirring device and stirring at 200 r / min for 10 min at 20℃. Then, the organosilicon coupling agent and surfactant are added, and the stirring speed is increased to 500 r / min for 20 min to form a homogeneous solution.

[0025] The connecting liquid in step two is made from the following raw materials in parts by weight: 50 parts isocyanate resin, 20 parts epoxy resin, 10 parts silane-modified polymer, 5 parts functional additives, 2 parts antioxidant, and 10 parts solvent. The isocyanate resin is diphenylmethane diisocyanate or toluene diisocyanate; the epoxy resin is bisphenol A type epoxy resin; the silane-modified polymer is silane-modified polyether or silane-modified polyurethane; the functional additive is plasma-treated ceramic micropowder or carbon nanotubes; the antioxidant is hindered phenols or phosphites; and the solvent is xylene or ethyl acetate. The solid content of the connecting liquid is 40%, and the viscosity is [missing information]. .

[0026] The preparation method of the bonding fluid includes: adding isocyanate resin and epoxy resin into a temperature-controlled reactor, controlling the temperature at 25°C, stirring at 300 r / min for 15 min to prepolymerize the resin, adding silane-modified polymer, continuing to stir for 10 min, then adding solvent and antioxidant, stirring at 500 r / min for 15 min, finally adding functional additives, increasing the speed to 800 r / min and stirring for 30 min until uniformly mixed, filtering and storing in a sealed container, with a shelf life of no more than 7 days.

[0027] The functional additives are prepared by the following method: industrial waste ceramics or glass fibers are collected, sorted, and then soaked in a pickling tank with 5% hydrochloric acid solution for 1 hour. They are then rinsed with deionized water until neutral, dried in an oven at 80°C for 2 hours, and then crushed and ground using a ball mill. The resulting ceramic particles, with a particle size of 50 μm, are sieved and spread evenly in a plasma treatment chamber, where a vacuum is drawn to a pressure of [pressure value missing]. Pa, nitrogen or argon gas is introduced at a flow rate of 20 sccm, and then a plasma generator is used to process it for 10 minutes at a power of 400W.

[0028] Step 3, the coating of the connecting fluid, includes: using a spraying device or an airless spray gun to uniformly spray the connecting fluid onto the surface of the pipe end, with a spraying pressure of 0.3 MPa, a spraying speed of 10 cm / s, and a coating thickness of 0.1 mm. After coating, let it stand at room temperature for 5 minutes, and then place the coated area in a 60°C environment for 2 minutes. The ambient temperature of the coating operation is controlled at 15°C and the ambient humidity is below 70%.

[0029] In step four, the heat shrink tape is wrapped with a 50% overlap to ensure no air bubbles or wrinkles. The hot melt adhesive inside the heat shrink tape is ethylene-vinyl acetate copolymer or polyamide hot melt adhesive with a melt index of 10g / 10min. Before wrapping, the heat shrink tape needs to be preheated at 40℃ for 1min. After wrapping, use a pressure roller to roll out the air at a pressure of 0.1MPa.

[0030] In step five, during the heat shrinking process, the heating device moves uniformly along the circumference of the heat shrink tape. The heating time is 3 minutes, and the temperature gradient is controlled as follows: initial preheating at 100℃ for 1 minute, then increasing to 150℃ for main shrinking for 2 minutes, and finally holding at 120℃ for 1 minute to allow the hot melt adhesive to flow fully. The heating distance is 10 cm. After heat shrinking, the volume resistivity of the joint is not less than [value missing]. The sealing pressure shall not be less than 0.5 MPa.

[0031] In step six, during the curing and cooling process, the joint can be left to cool and cure naturally in a natural environment for 2 hours, or a forced air cooling device can be used to accelerate the cooling at a wind speed of 5 m / s for 0.5 hours to reduce the temperature of the joint to below 40℃. After curing, the joint should be visually inspected to ensure that the surface of the heat shrink tape is flat, the hot melt adhesive is evenly overflowing and there are no visible defects before proceeding with the subsequent trench backfilling construction.

[0032] Example 2: A method for quick connection of high-strength steel strip double-wall corrugated pipe using heat-shrinkable tape, comprising the following steps: Step 1: Pretreatment, surface treatment of the connecting ends of the steel strip double-wall corrugated pipe, including degreasing, roughening and drying; Step 2: Preparation of the bonding fluid, which consists of adhesive resin, reinforcing agent and functional filler; Step 3: Applying the connecting fluid, uniformly applying the connecting fluid to the pretreated pipe end surface; Step 4: Wrap with heat shrink tape. Spiral-wrap or loop the heat shrink tape around the end of the pipe coated with the bonding fluid, ensuring that the bonding area is covered. Step 5: Heat shrinking treatment. A heating device is used to heat and shrink the heat shrink tape, so that the bonding liquid melts and adheres to the heat shrink tape. Step Six: Curing and Cooling. Natural cooling or forced air cooling will allow the joint to cure and form a high-strength sealed connection.

[0033] The steel-reinforced double-wall corrugated pipe is made of high-density polyethylene and steel strip composite structure. The pipe diameter range is 600mm, the wall thickness is 3mm, the heat shrink tape is radiation cross-linked polyethylene substrate, with built-in hot melt adhesive layer, thickness is 1.5mm, width is 200mm, and the heating device is infrared heater, hot air gun or flame torch, with a heating temperature of 160℃.

[0034] The pretreatment in step one includes the following steps: immerse the pipe connection end in a stainless steel tank of degreasing solution at room temperature for 1 hour. During the immersion process, use a mechanical stirrer at 100 r / min to stir and remove surface oil and oxides. After removal, rinse with a high-pressure water gun at 10 MPa pressure for 10 minutes to remove residual degreasing solution. Then place it in an oven at 70℃ for 0.7 hours or air dry for 3 hours to ensure the surface moisture content is below 5%. The roughening treatment uses a sandblasting machine or sandpaper to polish the surface to a roughness Ra of 4.5 μm.

[0035] The degreasing solution is composed of the following components in the following mass ratio: 65 parts ethanol, 15 parts acetone, 7 parts organosilicon coupling agent, 3 parts surfactant, and 15 parts deionized water. The ethanol concentration is 97%, the acetone purity is ≥99%, the organosilicon coupling agent is γ-aminopropyltriethoxysilane, and the surfactant is sodium dodecylbenzenesulfonate or polyoxyethylene ether. The degreasing solution is prepared by adding ethanol, acetone, and deionized water to a stirring device and stirring at 350 r / min for 15 min at 25°C. Then, the organosilicon coupling agent and surfactant are added, and the stirring speed is increased to 700 r / min for 30 min to form a homogeneous solution.

[0036] The connecting liquid in step two is made from the following raw materials in parts by weight: 55 parts isocyanate resin, 25 parts epoxy resin, 12 parts silane-modified polymer, 7 parts functional additives, 3 parts antioxidant, and 15 parts solvent. The isocyanate resin is diphenylmethane diisocyanate or toluene diisocyanate; the epoxy resin is bisphenol A type epoxy resin; the silane-modified polymer is silane-modified polyether or silane-modified polyurethane; the functional additive is plasma-treated ceramic micropowder or carbon nanotubes; the antioxidant is hindered phenols or phosphites; and the solvent is xylene or ethyl acetate. The solid content of the connecting liquid is 50%, and the viscosity is [missing information]. .

[0037] The preparation method of the bonding fluid includes: adding isocyanate resin and epoxy resin into a temperature-controlled reactor, controlling the temperature at 30°C, stirring at 450 r / min for 20 min to prepolymerize the resin, adding silane-modified polymer, continuing to stir for 15 min, then adding solvent and antioxidant, stirring at 650 r / min for 20 min, finally adding functional additives, increasing the speed to 1000 r / min and stirring for 45 min until uniformly mixed, filtering and storing in a sealed container, with a shelf life of no more than 7 days.

[0038] The functional additives are prepared by the following method: industrial waste ceramics or glass fibers are collected, sorted, and then soaked in a pickling tank with 7% hydrochloric acid solution for 1.5 hours. They are then rinsed with deionized water until neutral, dried in a 90°C oven for 2.5 hours, crushed and ground using a ball mill, and sieved to obtain ceramic microparticles with a particle size of 70 μm. These ceramic microparticles are then spread evenly in a plasma treatment chamber, and a vacuum is drawn to a pressure... Pa, nitrogen or argon gas is introduced at a flow rate of 40 sccm, and then a plasma generator is used to process it for 15 minutes at a power of 600W.

[0039] Step 3, the coating of the connecting fluid, includes: using a spraying device or an airless spray gun to uniformly spray the connecting fluid onto the surface of the pipe end, with a spraying pressure of 0.4 MPa, a spraying speed of 15 cm / s, and a coating thickness of 0.2 mm. After coating, let it stand at room temperature for 10 minutes, and then place the coated area in a 70°C environment for 3 minutes. The ambient temperature of the coating operation is controlled at 25°C and the ambient humidity is below 70%.

[0040] In step four, the heat shrink tape is wrapped with an overlap rate of 55% to ensure no air bubbles or wrinkles. The hot melt adhesive inside the heat shrink tape is ethylene-vinyl acetate copolymer or polyamide hot melt adhesive with a melt index of 20g / 10min. Before wrapping, the heat shrink tape needs to be preheated at 50℃ for 1.5min. After wrapping, use a pressure roller to roll out the air at a pressure of 0.2MPa.

[0041] In step five, during the heat shrinking process, the heating device moves uniformly along the circumference of the heat shrink tape. The heating time is 5 minutes, and the temperature gradient is controlled as follows: initial preheating at 110℃ for 1.5 minutes, then increasing to 160℃ for main shrinking for 3 minutes, and finally holding at 130℃ for 2 minutes to allow the hot melt adhesive to flow fully. The heating distance is 15 cm. After heat shrinking, the volume resistivity at the joint is not less than [value missing]. The sealing pressure shall not be less than 0.5 MPa.

[0042] In step six, during the curing and cooling process, the joint can be left to stand in a natural environment for 3 hours to allow it to cool and cure naturally, or a forced air cooling device can be used to accelerate the cooling at a wind speed of 7 m / s for 0.7 hours to reduce the temperature of the joint to below 40°C. After curing, the joint should be visually inspected to ensure that the surface of the heat shrink tape is flat, the hot melt adhesive is evenly overflowing and there are no visible defects before proceeding with the subsequent trench backfilling construction.

[0043] Example 3: A heat-shrinkable tape quick-connect method for high-strength steel strip double-wall corrugated pipes, comprising the following steps: Step 1: Pretreatment, surface treatment of the connecting ends of the steel strip double-wall corrugated pipe, including degreasing, roughening and drying; Step 2: Preparation of the bonding fluid, which consists of adhesive resin, reinforcing agent and functional filler; Step 3: Applying the connecting fluid, uniformly applying the connecting fluid to the pretreated pipe end surface; Step 4: Wrap with heat shrink tape. Spiral-wrap or loop the heat shrink tape around the end of the pipe coated with the bonding fluid, ensuring that the bonding area is covered. Step 5: Heat shrinking treatment. A heating device is used to heat and shrink the heat shrink tape, so that the bonding liquid melts and adheres to the heat shrink tape. Step Six: Curing and Cooling. Natural cooling or forced air cooling will allow the joint to cure and form a high-strength sealed connection.

[0044] The steel-reinforced double-wall corrugated pipe is made of high-density polyethylene and steel strip composite structure. The pipe diameter range is 1000mm, the wall thickness is 5mm, the heat shrink tape is radiation cross-linked polyethylene substrate, with an internal hot melt adhesive layer, the thickness is 2.0mm, the width is 300mm, and the heating device is an infrared heater, hot air gun or flame torch, with a heating temperature of 200℃.

[0045] The pretreatment in step one includes the following steps: immerse the pipe connection end in a stainless steel tank of degreasing solution at room temperature for 1.5 hours. During the immersion process, use a mechanical stirrer at 150 r / min to stir and remove surface oil and oxides. After removal, rinse with a high-pressure water gun at 15 MPa pressure for 15 minutes to remove residual degreasing solution. Then place it in an oven at 80℃ for 1 hour or air dry naturally for 4 hours to reduce the surface moisture content to below 5%. The roughening treatment uses a sandblasting machine or sandpaper to polish the surface to a surface roughness Ra of 6.3 μm.

[0046] The degreasing solution is composed of the following components in the following mass ratio: 70 parts ethanol, 20 parts acetone, 10 parts organosilicon coupling agent, 5 parts surfactant, and 20 parts deionized water. The ethanol concentration is 99%, the acetone purity is ≥99%, the organosilicon coupling agent is γ-aminopropyltriethoxysilane, and the surfactant is sodium dodecylbenzenesulfonate or polyoxyethylene ether. The degreasing solution is prepared by adding ethanol, acetone, and deionized water to a stirring device and stirring at 500 r / min for 20 min at 30℃. Then, the organosilicon coupling agent and surfactant are added, and the stirring speed is increased to 1000 r / min for 40 min to form a homogeneous solution.

[0047] The connecting liquid in step two is made from the following raw materials in parts by weight: 60 parts isocyanate resin, 30 parts epoxy resin, 15 parts silane-modified polymer, 10 parts functional additives, 5 parts antioxidants, and 20 parts solvent. The isocyanate resin is diphenylmethane diisocyanate or toluene diisocyanate; the epoxy resin is bisphenol A type epoxy resin; the silane-modified polymer is silane-modified polyether or silane-modified polyurethane; the functional additives are plasma-treated ceramic micropowder or carbon nanotubes; the antioxidants are hindered phenols or phosphites; and the solvent is xylene or ethyl acetate. The solid content of the connecting liquid is 60%, and the viscosity is [missing information]. .

[0048] The preparation method of the bonding fluid includes: adding isocyanate resin and epoxy resin into a temperature-controlled reactor, controlling the temperature at 35°C, stirring at 600 r / min for 25 min to prepolymerize the resin, adding silane-modified polymer, continuing to stir for 20 min, then adding solvent and antioxidant, stirring at 800 r / min for 30 min, finally adding functional additives, increasing the speed to 1200 r / min and stirring for 50 min until uniformly mixed, filtering and storing in a sealed container, with a shelf life of no more than 7 days.

[0049] The functional additives are prepared by the following method: industrial waste ceramics or glass fibers are collected, sorted, and then soaked in a pickling tank with 10% hydrochloric acid solution for 2 hours. They are then rinsed with deionized water until neutral, dried in an oven at 100℃ for 3 hours, crushed and ground using a ball mill, and sieved to obtain ceramic microparticles with a particle size of 100 μm. These ceramic microparticles are then spread evenly in a plasma treatment chamber, and a vacuum is drawn to a pressure... The gas is introduced at a flow rate of 60 sccm using nitrogen or argon, and then treated for 20 minutes using a plasma generator at a power of 800W.

[0050] Step 3, the coating of the connecting fluid, includes: using a spraying device or an airless spray gun to uniformly spray the connecting fluid onto the surface of the pipe end, with a spraying pressure of 0.6 MPa, a spraying speed of 20 cm / s, and a coating thickness of 0.3 mm. After coating, let it stand at room temperature for 15 minutes, and then place the coated area in an 80°C environment for 5 minutes. The ambient temperature of the coating operation is controlled at 30°C and the ambient humidity is below 70%.

[0051] In step four, the heat shrink tape is wrapped with a 60% overlap to ensure no bubbles or wrinkles. The hot melt adhesive inside the heat shrink tape is ethylene-vinyl acetate copolymer or polyamide hot melt adhesive with a melt index of 30g / 10min. Before wrapping, the heat shrink tape needs to be preheated at 60℃ for 2 minutes. After wrapping, use a pressure roller to roll out the air at a pressure of 0.3MPa.

[0052] In step five, during the heat shrinking process, the heating device moves uniformly along the circumference of the heat shrink tape. The heating time is 10 minutes, and the temperature gradient is controlled as follows: initial preheating at 120℃ for 2 minutes, then increasing to 180℃ for main shrinking for 5 minutes, and finally holding at 140℃ for 3 minutes to allow the hot melt adhesive to flow fully. The heating distance is 20 cm. After heat shrinking, the volume resistivity of the joint is not less than [value missing]. The sealing pressure shall not be less than 0.5 MPa.

[0053] In step six, during the curing and cooling process, the joint can be left to cool and cure naturally in a natural environment for 4 hours, or a forced air cooling device can be used to accelerate the cooling for 1 hour at a wind speed of 10 m / s to reduce the temperature of the joint to below 40°C. After curing, the joint should be visually inspected to ensure that the surface of the heat shrink tape is flat, the hot melt adhesive is evenly overflowing and there are no visible defects before proceeding with the subsequent trench backfilling construction.

[0054] The performance of the heat-shrinkable tape connectors of the high-strength steel strip double-wall corrugated pipes prepared in Examples 1-3 and Comparative Examples 1-4 was tested. The test items and test methods are as follows: Peel strength test: Under the standard environment of temperature 23±2℃ and humidity 50±5%, a universal testing machine was used to peel the overlap edge of the heat shrink tape along the axial direction of the pipe at a constant speed of 100mm / min. The force value during the peeling process was recorded and the average peel force per unit width was calculated. For the sealing test, place the connected pipe section flat, seal one end, inject clean water from the other end and remove air, then connect the pressurization system and uniformly raise the internal water pressure to 0.6MPa at room temperature, maintain the pressure for 30 minutes, and observe the change in the pressure gauge value and whether there is any leakage or cracking on the outer surface of the connection part. For the pressure resistance test, the two ends of the sample are sealed and completely immersed in the water tank. Dry compressed air is introduced into the tube, and the pressure is gradually increased to 0.02MPa and kept stable. The pressure holding time is 5 minutes. During this period, visual inspection is performed to check whether there are continuous bubbles escaping from the submerged part. For the thermal cycling test, the connection sample is placed in a high and low temperature alternating test chamber. The cycling conditions are set as follows: -20℃ for 2 hours to 60℃ for 2 hours as one cycle. Five cycles are performed continuously. After the test, the sample is allowed to recover at room temperature for 2 hours. Then, the sealing test is performed again according to the above method to check the performance changes.

[0055] The test data of the high-strength steel strip double-wall corrugated tube heat shrinkable tape joints prepared in Examples 1-3 and Comparative Examples 1-4 are recorded in the table below: By comparing and analyzing the data in the table, it can be seen that the high-strength steel strip double-wall corrugated pipe heat shrinkable tape joints prepared using the processes in Examples 1-3 have better peel strength and sealing pressure than comparative examples 1-4. This indicates that by systematically degreasing, roughening, and drying the pipe connection ends, removing surface contaminants and forming a suitable roughness, a clean and well-anchored substrate is provided for subsequent bonding. This solves the problem of weak bonding caused by interface contamination and microscopic defects, improves the basic firmness and consistency of the connection interface, and ensures the reliability of the connection quality. By applying a special bonding fluid, it fully melts and combines with the hot melt adhesive of the inner layer of the heat shrinkable tape during the heat shrinking process. This not only achieves physical sealing but also forms a strong chemical bond and mechanical interlock at the interface, enhancing the joint's resistance to creep and stress relaxation under long-term loads, thereby ensuring the long-term durability and stability of the sealing interface under complex working conditions. By optimizing the wrapping process of heat shrink tape and controlling the temperature curve of heat shrink treatment, the heat shrink tape is ensured to shrink evenly under heat and the hot melt adhesive is fully flowed and wetted. Combined with the controlled curing and cooling process, the joints are made into a dense and stable structure that resists external mechanical stress and temperature difference changes, ensuring the uniform and reliable performance of the joints and broadening the adaptability of construction.

[0056] By comparing and analyzing the relevant data in the table, it can be seen that the pipe joints prepared by the rapid connection method provided by this invention have excellent sealing reliability, mechanical strength, and long-term durability. This indicates that the connection method provided by this invention has a reasonable process and excellent overall performance.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for quick connection of high-strength steel strip double-wall corrugated pipe using heat-shrinkable tape, characterized in that: Includes the following steps: Step 1: Pretreatment, surface treatment of the connecting ends of the steel strip double-wall corrugated pipe, including degreasing, roughening and drying; Step 2: Preparation of the bonding fluid, which consists of adhesive resin, reinforcing agent and functional filler; Step 3: Applying the connecting fluid, uniformly applying the connecting fluid to the pretreated pipe end surface; Step 4: Wrap with heat shrink tape. Spiral-wrap or loop the heat shrink tape around the end of the pipe coated with the bonding fluid, ensuring that the bonding area is covered. Step 5: Heat shrinking treatment. A heating device is used to heat and shrink the heat shrink tape, so that the bonding liquid melts and adheres to the heat shrink tape. Step Six: Curing and Cooling. Allow the joint to cure and solidify naturally or through forced air cooling, forming a high-strength sealed connection. The steel-reinforced double-wall corrugated pipe is made of high-density polyethylene and steel strip composite structure, with a pipe diameter range of 200-1000mm and a wall thickness of 2-5mm. The heat shrinkable tape is made of radiation cross-linked polyethylene substrate with an internal hot melt adhesive layer, a thickness of 1.0-2.0mm and a width of 100-300mm. The heating device is an infrared heater, a hot air gun or a flame torch, with a heating temperature of 120-200℃.

2. The heat-shrinkable tape quick connection method for high-strength steel strip double-wall corrugated pipe according to claim 1, characterized in that: The pretreatment in step one includes the following steps: immersing the pipe connection end in a stainless steel tank of degreasing solution at room temperature for 0.5-1.5 hours, using a mechanical stirrer at 50-150 r / min during the immersion process to remove surface oil and oxides; after removal, rinsing with a high-pressure water gun at 5-15 MPa pressure for 5-15 minutes to remove residual degreasing solution; then placing it in an oven at 60-80℃ for 0.5-1 hour, or air-drying naturally for 2-4 hours, so that the surface moisture content is less than 5%; the roughening treatment uses a sandblasting machine or sandpaper to polish the surface roughness Ra to 3.2-6.3 μm.

3. The heat-shrinkable tape quick connection method for high-strength steel strip double-wall corrugated pipe according to claim 2, characterized in that: The degreasing solution is composed of the following components in the following mass ratio: 60-70 parts ethanol, 10-20 parts acetone, 5-10 parts organosilicon coupling agent, 2-5 parts surfactant, and 10-20 parts deionized water. The ethanol concentration is 95%-99%, the acetone purity is ≥99%, the organosilicon coupling agent is one of γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane, and the surfactant is sodium dodecylbenzenesulfonate or polyoxyethylene ether. The degreasing solution is prepared by adding ethanol, acetone, and deionized water to a stirring device and stirring at 200-500 r / min for 10-20 min at 20-30℃. Then, the organosilicon coupling agent and surfactant are added, and the stirring speed is increased to 500-1000 r / min for 20-40 min to form a homogeneous solution.

4. The heat-shrinkable tape quick connection method for high-strength steel strip double-wall corrugated pipe according to claim 1, characterized in that: The connecting liquid in step two is made from the following raw materials in parts by weight: 50-60 parts isocyanate resin, 20-30 parts epoxy resin, 10-15 parts silane-modified polymer, 5-10 parts functional additives, 2-5 parts antioxidants, and 10-20 parts solvent. The isocyanate resin is diphenylmethane diisocyanate or toluene diisocyanate, the epoxy resin is bisphenol A type epoxy resin, the silane-modified polymer is silane-modified polyether or silane-modified polyurethane, the functional additives are plasma-treated ceramic micropowder or carbon nanotubes, the antioxidants are hindered phenols or phosphites, and the solvent is xylene or ethyl acetate. The solid content of the connecting liquid is 40%-60%, and the viscosity range is [not specified in the original text]. .

5. The heat-shrinkable tape quick connection method for high-strength steel strip double-wall corrugated pipe according to claim 4, characterized in that: The preparation method of the connecting liquid includes: adding isocyanate resin and epoxy resin into a temperature-controlled reactor, controlling the temperature at 25-35℃, stirring at 300-600 r / min for 15-25 min to prepolymerize the resin, adding silane-modified polymer, continuing to stir for 10-20 min, then adding solvent and antioxidant, stirring at 500-800 r / min for 15-30 min, finally adding functional additives, increasing the speed to 800-1200 r / min and stirring for 30-50 min until uniformly mixed, filtering and storing in a sealed container, with a shelf life of no more than 7 days.

6. The heat-shrinkable tape quick connection method for high-strength steel strip double-wall corrugated pipe according to claim 4, characterized in that: The functional additive is prepared by the following method: industrial waste ceramics or glass fibers are collected, sorted, and then soaked in a pickling tank with a 5%-10% hydrochloric acid solution for 1-2 hours. The mixture is then rinsed with deionized water until neutral, dried in an oven at 80-100℃ for 2-3 hours, crushed and ground using a ball mill, and sieved to obtain ceramic microparticles with a particle size of 50-100 μm. The ceramic microparticles are then spread evenly in a plasma treatment chamber, and a vacuum is drawn to a pressure... to At Pa, nitrogen or argon gas is introduced at a flow rate of 20-60 sccm, followed by treatment with a plasma generator at a power of 400-800W for 10-20 minutes.

7. The method for quick connection of high-strength steel strip double-wall corrugated pipe by heat shrink tape according to claim 1, characterized in that: The bonding fluid coating in step three includes: uniformly spraying the bonding fluid onto the end surface of the pipe using a spraying device or an airless spray gun, with a spraying pressure of 0.3-0.6 MPa, a spraying speed of 10-20 cm / s, and a coating thickness of 0.1-0.3 mm. After coating, the area is left to stand at room temperature for 5-15 minutes, and then the coated area is placed in an environment of 60-80℃ for 2-5 minutes. The ambient temperature during the coating operation is controlled at 15-30℃, and the ambient humidity is below 70%.

8. The heat-shrinkable tape quick connection method for high-strength steel strip double-wall corrugated pipe according to claim 1, characterized in that: In step four, the heat shrink tape wrapping process involves an overlap rate of 50%-60% to ensure no air bubbles or wrinkles. The hot melt adhesive embedded in the heat shrink tape is an ethylene-vinyl acetate copolymer or a polyamide hot melt adhesive with a melt index of 10-30 g / 10 min. Before wrapping, the heat shrink tape needs to be preheated at 40-60℃ for 1-2 minutes. After wrapping, the tape is rolled with a pressure roller to remove air at a pressure of 0.1-0.3 MPa.

9. The heat-shrinkable tape quick connection method for high-strength steel strip double-wall corrugated pipe according to claim 1, characterized in that: In step five, the heat shrinking process, the heating device moves uniformly along the circumference of the heat shrinkable tape. The heating time is 3-10 minutes, and the temperature gradient is controlled as follows: initial preheating at 100-120℃ for 1-2 minutes, then increasing to 150-180℃ for main shrinking for 2-5 minutes, and finally holding at 120-140℃ for 1-3 minutes to allow the hot melt adhesive to flow fully. The heating distance is 10-20 cm. After heat shrinking, the volume resistivity of the joint is not less than [value missing]. The sealing pressure shall not be less than 0.5 MPa.

10. The method for quick connection of high-strength steel strip double-wall corrugated pipe by heat shrink tape according to claim 1, characterized in that: In step six, during the curing and cooling process, the joint can be left to stand in a natural environment for 2-4 hours to allow it to cool and solidify naturally, or a forced air cooling device can be used to accelerate the cooling at a wind speed of 5-10 m / s for 0.5-1 hours to reduce the temperature of the joint to below 40°C. After curing, the joint should be visually inspected to ensure that the surface of the heat shrink tape is flat, the hot melt adhesive is evenly overflowing, and there are no visible defects. Then, the subsequent trench backfilling construction can proceed.

Images