Anti-corrosion rotational molding process steel lining pipeline and manufacturing method thereof

Abstract

The invention relates to the field of rotational molding pipelines, and particularly discloses an anti-corrosion rotational molding process steel lining pipeline and a manufacturing method thereof. The steel pipe base body, the transition bonding layer and the lining anti-corrosion layer are arranged in the steel pipe, the bonding force between the lining anti-corrosion layer and the steel pipe base body can be effectively improved through the transition bonding layer, the lining anti-corrosion layer is prevented from falling off from the steel pipe base body in the long-term use process, meanwhile, components of the lining anti-corrosion layer are improved, and the service life of the lining anti-corrosion layer is prolonged. The use strength of the lining anti-corrosion layer is effectively improved, the situation that the overall anti-corrosion capacity of the pipeline is reduced due to the fact that the lining anti-corrosion layer is abraded too much in the long-term use process is avoided, and compared with a common rotational molding pipeline, the high-strength rotational molding pipeline has more excellent use strength and anti-corrosion capacity.

Description

Technical Field

[0001] The present invention belongs to the technical field of rotationally molded pipes, and in particular relates to an anti-corrosion rotationally molded steel-lined pipe and a manufacturing method thereof. Background Art

[0002] In industrial production and many other fields, pipelines are key components for transporting various media, and their performance directly impacts production stability and safety. This is especially true when transporting media such as acids, alkalis, salts, and corrosive gases, placing extremely high demands on pipeline corrosion resistance. While traditional metal pipelines offer excellent mechanical strength, they are susceptible to corrosion when exposed to highly corrosive media, shortening their service life and causing leaks. This not only increases maintenance costs but can also lead to safety incidents.

[0003] To address these issues, roto-molded pipes were developed. Composed of an inner plastic layer and an outer steel pipe layer, roto-molded pipes combine the mechanical properties of steel pipe with the corrosion resistance of engineering plastics. However, existing plastic-lined pipe manufacturing processes still have some shortcomings. During the roto-molded pipe formation process, the plastic components are relatively simple, resulting in insufficient bond strength between the molten plastic and the steel pipe, which can easily cause the lining layer to loosen. Furthermore, the plastic's insufficient strength can cause wear on the surface of the plastic lining after prolonged use, further reducing the pipe's corrosion resistance. Consequently, the internal roto-molding of existing roto-molded pipes presents significant operational drawbacks. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a corrosion-resistant roto-molded steel-lined pipe and a manufacturing method thereof, so as to solve the problem of usage defects in the internal roto-molded pipe of the existing roto-molded pipe.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An anti-corrosion rotational molding steel-lined pipeline, comprising:

[0007] Steel pipe matrix;

[0008] A transition bonding layer is formed on the inner wall of the steel pipe substrate by a spraying process;

[0009] The lining anti-corrosion layer is formed on the inner wall of the transition adhesive layer through a rotational molding process.

[0010] Preferably, the thickness of the transition bonding layer is 0.2 mm, and the thickness of the lining anti-corrosion layer is 2-10 mm.

[0011] A method for manufacturing a corrosion-resistant roto-molding steel-lined pipe, which is applied to an corrosion-resistant roto-molding steel-lined pipe, comprises:

[0012] S1, cleaning, derusting and sandblasting the steel pipe substrate to obtain a pretreated steel pipe substrate;

[0013] S2, heating the pretreated steel pipe substrate to 150-250°C;

[0014] S3, spraying the transition adhesive material evenly on the inner wall of the steel pipe substrate through a spraying device to form a transition adhesive layer;

[0015] S4, evenly coating the anti-corrosion material on the inner wall of the pretreated steel pipe substrate through a rotational molding process to form an inner lining anti-corrosion layer;

[0016] S5, cooling the steel pipe substrate with the inner lining anti-corrosion layer to 20-50° C. to obtain an anti-corrosion rotationally molded steel lined pipe;

[0017] S6, perform thickness testing, adhesion testing and corrosion resistance testing on steel lined pipes.

[0018] Preferably, in S1, the abrasives used in the sandblasting process include steel sand and quartz sand, the abrasive particle size is 0.5-1.5 mm, the sandblasting pressure is 0.5-0.8 MPa, and the inner wall roughness of the steel pipe substrate is Ra20-50 μm.

[0019] Preferably, in S2, the pretreated steel pipe substrate is uniformly heated by electric heating or gas heating, and the heating time is 10-30 minutes.

[0020] Preferably, in S3, after the transition adhesive material is evenly sprayed on the inner wall of the steel pipe substrate by a spraying device, the steel pipe substrate with the transition adhesive material is placed in a curing furnace and cured at a temperature of 150-180°C for 30 minutes to form a transition adhesive layer on the inner wall of the steel pipe substrate. The raw materials of the transition adhesive material are epoxy resin and silane coupling agent, and the epoxy resin and silane coupling agent are melt-mixed in a weight ratio of 85% to 95%: 3% to 6%, and then extruded to form transition adhesive material particles, which are then ground into powder to obtain the transition adhesive material.

[0021] Preferably, in S4, the components of the anti-corrosion material include a base resin, an adhesive and an additive. The base resin, the adhesive and the additive are melt-mixed in a weight ratio of 93% to 96%: 4.5% to 5%: 2% to 3%, and then extruded to form anti-corrosion material particles, which are then ground into powder to obtain the anti-corrosion material. The base resin includes polyethylene, polypropylene, polyoxymethylene, polyolefin elastomer, nylon, polylactic acid and polycarbonate materials. The adhesive includes polyethylene wax, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, EVA wax, oxidized polyethylene wax, POE, EVA, EAA, polyethylene grafts and polypropylene grafts. The additives are calcium stearate, antioxidants and ultra-high molecular weight polyethylene. The powder flowability of the anti-corrosion material is 20-40q / s.

[0022] Preferably, in S5, the cooling rate of the steel tube substrate is 1-5°C / min.

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

[0024] The present invention arranges a steel pipe substrate, a transition bonding layer and an inner lining anti-corrosion layer inside the steel pipe. The transition bonding layer can effectively improve the bonding force between the inner lining anti-corrosion layer and the steel pipe substrate, thereby preventing the inner lining anti-corrosion layer from falling off from the steel pipe substrate during long-term use. At the same time, the components of the inner lining anti-corrosion layer are improved to effectively improve the use strength of the inner lining anti-corrosion layer, thereby preventing the inner lining anti-corrosion layer from being excessively worn during long-term use and reducing the overall anti-corrosion ability of the pipeline. Compared with general rotationally molded pipes, the present invention has better use strength and anti-corrosion ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the overall structure of a steel-lined pipeline using an anti-corrosion rotational molding process disclosed in the present invention;

[0026] Figure 2 This is a flowchart of a method for manufacturing a steel-lined pipe using an anti-corrosion rotational molding process disclosed in the present invention;

[0027] In the figure: 1. Steel pipe substrate; 2. Transition bonding layer; 3. Lining anti-corrosion layer. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] Example 1:

[0030] See also Figure 1 - Figure 2 As shown, an anti-corrosion rotational molding steel-lined pipeline includes:

[0031] Steel pipe substrate 1;

[0032] The transition adhesive layer 2 is formed on the inner wall of the steel pipe substrate 1 by a spraying process;

[0033] The lining anti-corrosion layer 3 is formed on the inner wall of the transition adhesive layer 2 by a rotational molding process.

[0034] As can be seen from the above, a transition bonding layer 2 is first sprayed inside the steel pipe substrate 1 to improve the adhesion of the inner wall of the steel pipe substrate 1, and then an inner lining anti-corrosion layer 3 is formed on the transition bonding layer 2 through a rotational molding process. The inner lining anti-corrosion layer effectively improves the corrosion resistance of the steel pipe substrate 1.

[0035] The thickness of the transition bonding layer 2 is 0.2 mm, and the thickness of the lining anti-corrosion layer 3 is 2-10 mm.

[0036] A method for manufacturing a corrosion-resistant roto-molding steel-lined pipe, which is applied to an corrosion-resistant roto-molding steel-lined pipe, comprises:

[0037] S1, cleaning, derusting and sandblasting the steel pipe substrate 1 to obtain a pretreated steel pipe substrate 1, wherein the abrasives used in the sandblasting include steel sand and quartz sand, the abrasive particle size is 0.5-1.5 mm, the sandblasting pressure is 0.5-0.8 MPa, and the inner wall roughness of the steel pipe substrate 1 is Ra20-50 μm. Sandblasting improves the inner wall roughness of the steel pipe substrate 1, which helps the transition adhesive layer 2 adhere to the inner wall of the steel pipe substrate 1 and enhances the bonding strength between the two;

[0038] S2, heating the pretreated steel tube substrate 1 to 150-250° C., and evenly heating the pretreated steel tube substrate 1 by electric heating or gas heating, and the heating time is 10-30 minutes;

[0039] S3, uniformly spraying a transition adhesive material onto the inner wall of the steel pipe substrate 1 using a spraying device, placing the steel pipe substrate 1 with the transition adhesive material in a curing furnace, and curing it at a temperature of 150-180° C. for 30 minutes to form a transition adhesive layer 2 on the inner wall of the steel pipe substrate 1, wherein the raw materials of the transition adhesive material are epoxy resin and silane coupling agent, which are melt-mixed by extruding the epoxy resin and silane coupling agent in a weight ratio of 85% to 95%:3% to 6% to form transition adhesive material particles, which are then ground into powder to obtain the transition adhesive material;

[0040] S4, the anti-corrosion material is evenly coated on the inner wall of the pretreated steel pipe substrate 1 by a rotational molding process to form an inner lining anti-corrosion layer 3, the components of the anti-corrosion material include a base resin, an adhesive and an additive, the base resin, the adhesive and the additive are melt-mixed in a weight ratio of 93% to 96%: 4.5% to 5%: 2% to 3% and then extruded to form anti-corrosion material particles, and the anti-corrosion material is obtained after grinding, the base resin includes polyethylene, polypropylene, polyoxymethylene, polyolefin elastomer, nylon, polylactic acid and polycarbonate materials, the adhesive includes polyethylene wax, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, EVA wax, oxidized polyethylene wax, POE, EVA, EAA, polyethylene graft and polypropylene graft, the additives are calcium stearate, antioxidant and ultra-high molecular weight polyethylene, the blending mass fraction of calcium stearate is 0.2%, which can improve the strength, rigidity and toughness of the lining anti-corrosion layer, making its mechanical properties better, the antioxidant can improve the antioxidant ability and UV protection ability of the lining anti-corrosion layer, and prevent the pipeline from being excessively oxidized during the construction period, and the ultra-high molecular weight polyethylene and calcium stearate work together to further improve the strength of the lining anti-corrosion layer 1, thereby improving the wear resistance of the lining anti-corrosion layer, and the powder flowability of the anti-corrosion material is 20-40q / s;

[0041] S5, cooling the steel pipe substrate 1 with the inner lining anti-corrosion layer 3 to 20-50°C to obtain an anti-corrosion rotationally molded steel lined pipe. The cooling rate of the steel pipe substrate 1 is 1-5°C / min. The cooling method can be natural cooling or forced cooling, or both can be used to control the cooling rate of the steel pipe substrate 1. Try to avoid the steel pipe substrate 1 cooling too fast, which may cause internal stress in the inner lining anti-corrosion layer 3 and affect the quality of the pipe.

[0042] S6: Steel-lined pipelines undergo thickness, adhesion, and corrosion resistance tests. The lining surface must be smooth, free of bubbles, leaks, obvious scratches, wrinkles, and other defects. A combination of visual and tactile inspections ensures that every lining surface is carefully examined. The plastic lining is tested using a spark detector to detect defects such as cracks. During testing, the detector probe is slowly moved along the lining surface, and an appropriate test voltage is set. If defects are detected, the detector will sound an alarm. The steel-lined pipeline is then subjected to a hydrostatic test to verify its pressure resistance and leak-tightness. Seal both ends of the pipeline, inject water, and gradually increase the pressure to the specified test pressure, generally 1.5 to 2 times the operating pressure. Maintain the test pressure for a specified period of time, and observe the pipeline for leaks, deformation, and other signs. If no abnormalities are found during the test, the pipeline's pressure resistance and leak-tightness meet the requirements.

[0043] All standard parts used in the present invention can be purchased commercially, and special-shaped parts can be customized according to the description in the specification and drawings. The specific connection methods of each part adopt conventional means such as bolts, rivets, welding, etc. that are mature in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art. In addition, the circuit connections adopt conventional connection methods in the prior art and will not be described in detail here. Any matters not described in detail in this specification belong to the prior art known to professionals in this field.

[0044] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. "Multiple" means two or more, unless otherwise specifically defined.

[0045] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0046] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0047] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0048] In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

Claims

1. An anti-corrosion rotational molding steel lined pipe, characterized in that: include: Steel pipe base (1); A transition adhesive layer (2) is formed on the inner wall of the steel pipe substrate (1) by a spraying process; The lining anti-corrosion layer (3) is formed on the inner wall of the transition adhesive layer (2) through a rotational molding process.

2. The anti-corrosion rotational molding steel-lined pipe according to claim 1, characterized in that: The thickness of the transition adhesive layer (2) is 0.2 mm, and the thickness of the inner lining anti-corrosion layer (3) is 2-10 mm.

3. A method for manufacturing a corrosion-resistant roto-molding steel-lined pipe, characterized in that: An anti-corrosion rotationally molded steel-lined pipe according to any one of claims 1-2, comprising: S1, cleaning, derusting and sandblasting the steel pipe substrate (1) to obtain a pretreated steel pipe substrate (1); S2, heating the pretreated steel pipe substrate (1) to 150-250°C; S3, spraying the transition adhesive material evenly on the inner wall of the steel pipe substrate (1) through a spraying device to form a transition adhesive layer (2); S4, uniformly coating the anti-corrosion material on the inner wall of the pre-treated steel pipe substrate (1) through a rotational molding process to form an inner lining anti-corrosion layer (3); S5, cooling the steel pipe substrate (1) with the inner lining anti-corrosion layer (3) to 20-50° C. to obtain an anti-corrosion rotationally molded steel lined pipe; S6, perform thickness testing, adhesion testing and corrosion resistance testing on steel lined pipes.

4. The method for manufacturing a corrosion-resistant rotationally molded steel-lined pipe according to claim 3, characterized in that: In said S1, the abrasives used in the sandblasting process include steel sand and quartz sand, the abrasive particle size is 0.5-1.5 mm, the sandblasting pressure is 0.5-0.8 MPa, and the inner wall roughness of the steel pipe substrate (1) is Ra20-50 μm.

5. The method for manufacturing a corrosion-resistant rotationally molded steel-lined pipe according to claim 3, characterized in that: In S2, the pretreated steel pipe substrate (1) is uniformly heated by electric heating or gas heating, and the heating time is 10-30 minutes.

6. The method for manufacturing a corrosion-resistant roto-molding steel-lined pipe according to claim 3, characterized in that: In said S3, after the transition adhesive material is evenly sprayed on the inner wall of the steel pipe substrate (1) by a spraying device, the steel pipe substrate (1) with the transition adhesive material is placed in a curing furnace and cured at a temperature of 150-180° C. for 30 minutes to form a transition adhesive layer (2) on the inner wall of the steel pipe substrate (1). The raw materials of the transition adhesive material are epoxy resin and silane coupling agent. The epoxy resin and silane coupling agent are melt-mixed in a weight ratio of 85% to 95%: 3% to 6%, and then extruded to form transition adhesive material particles, which are then ground into powder to obtain the transition adhesive material.

7. The method for manufacturing a corrosion-resistant rotationally molded steel-lined pipe according to claim 3, characterized in that: In S4, the components of the anti-corrosion material include a base resin, an adhesive and an additive. The base resin, the adhesive and the additive are melt-mixed in a weight ratio of 93% to 96%: 4.5% to 5%: 2% to 3%, and then extruded to form anti-corrosion material particles, which are then ground into powder to obtain the anti-corrosion material. The base resin includes polyethylene, polypropylene, polyoxymethylene, polyolefin elastomer, nylon, polylactic acid and polycarbonate materials. The adhesive includes polyethylene wax, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, EVA wax, oxidized polyethylene wax, POE, EVA, EAA, polyethylene grafts and polypropylene grafts. The additives are calcium stearate, antioxidants and ultra-high molecular weight polyethylene. The powder flowability of the anti-corrosion material is 20-40q / s.

8. The method for manufacturing a corrosion-resistant roto-molding steel-lined pipe according to claim 3, characterized in that: In said S5, the cooling rate of said steel tube substrate (1) is 1-5°C / min.

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