Carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipeline and production process

Abstract

The invention discloses a carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipeline and a production process, and belongs to the technical field of flexible composite pipelines. In order to solve the problems that a traditional flexible pipeline is large in mass and high in transportation and installation cost, the flexible pipeline comprises a lining layer, a fiber metal composite reinforcing layer and an outer protection layer from inside to outside. Wherein the lining layer is made of a polyolefin material; the outer protection layer is made of a polyethylene material; a fiber metal composite reinforcing layer is arranged between the lining layer and the outer protective layer, and is prepared by winding a fiber metal composite belt formed by alternately compounding thermoplastic carbon fiber woven cloth and stainless steel ultra-thin belts on the lining layer in a spiral winding mode and an annular winding mode. The flexible pipeline has high toughness and ductility at the same time, most importantly, light weight of materials is achieved to a great extent, the transportation and installation cost is reduced, and the flexible pipeline has very wide application prospects in the fields of petroleum and natural gas transportation, aerospace, buildings and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible composite pipes, and in particular relates to a carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe and a production process. Background Art

[0002] In the past hundred years, traditional metal pipes have been the most commonly used materials for oil and gas transportation pipelines due to their low cost and high compressive strength. However, the defects of traditional metal pipes in weight, corrosion resistance and fatigue resistance have greatly limited their service life and greatly increased their transportation and installation costs. How to reduce the weight of the pipeline while ensuring good compressive strength and corrosion resistance has become a research hotspot. Flexible composite pipes have been increasingly used in domestic and foreign oil fields in recent years due to their advantages such as plastic flexibility, corrosion resistance, wear resistance, and easy laying. They have also been widely promoted and applied in aerospace and construction fields as corrosion-resistant and high-pressure resistant transmission pipelines.

[0003] The flexible composite pipe body is generally composed of a three-layer structure. The inner layer is mostly wear-resistant and corrosion-resistant polyolefin; the outer layer is generally made of polyethylene material, which mainly serves as a functional protective layer for anti-scratch and anti-static properties; and the most important of the three-layer structure is the middle reinforcement layer, the structure and material of which will determine the compressive performance of the flexible pipe. There are many types of reinforcement layers, commonly used ones are: steel wire, steel belt, glass fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, and composite belts formed by glass fiber, aramid fiber and resin, etc. The reinforcement belt is symmetrically and spirally wound on the inner layer at a certain angle to obtain a reinforcement layer. With the development of scientific research, more and more new materials are used in the reinforcement layer of flexible pipes in order to provide better compressive strength and reduce weight. In recent years, with the successful development and production of stainless steel ultra-thin strips by Taigang Group, the production of a carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe has become possible.

[0004] The carbon fiber / stainless steel ultra-thin strip composite material is used as the reinforcement layer of the flexible pipe, so that the flexible pipe has the high strength performance of carbon fiber and the high toughness and high ductility of stainless steel ultra-thin strip. And the flexible pipe has high specific strength, specific stiffness, specific modulus, excellent fatigue performance and damage tolerance. The most important thing is that it has achieved the lightweight of the material to a great extent, reduced the cost of transportation and installation, and has a very broad application prospect in the fields of oil and gas transportation, aerospace, construction, etc. Summary of the invention

[0005] In view of the problem that traditional flexible pipes have large weight and high transportation and installation costs, the present invention provides a carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe and a production process.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe, the flexible pipe is composed of an inner lining layer, a fiber metal composite reinforcement layer, and an outer protective layer from inside to outside;

[0008] The inner lining layer is made of polyolefin material with good wear resistance and corrosion resistance and low density;

[0009] The fiber metal composite reinforcement layer is prepared by winding a fiber metal composite tape formed by alternately compounding thermoplastic carbon fiber woven cloth and stainless steel ultra-thin tape on the inner layer by spiral winding and hoop winding;

[0010] The outer protective layer is made of polyethylene material with relatively high strength and heat resistance.

[0011] Furthermore, the inner diameter of the flexible pipe is 50-400 mm, and the thickness is 6-18 mm; wherein the thickness of the inner lining layer is 2-6 mm, the thickness of the fiber metal composite reinforcement layer is 2-6 mm, and the thickness of the outer protective layer is 2-6 mm.

[0012] Furthermore, the thermoplastic carbon fiber woven cloth adopts thermoplastic epoxy resin matrix carbon fiber woven cloth prepreg, with a width of 20 to 100 mm and a thickness of 150 μm; the stainless steel ultra-thin strip has a width of 20 to 100 mm and a thickness of 150 μm; the fiber metal composite strip has a width of 20 to 100 mm.

[0013] Furthermore, the spiral winding angle of the composite tape is ±53°, and the number of winding layers is 2 to 6 layers; the circumferential winding angle is 80° to 90°, and the number of winding layers is 2 to 6 layers; the thermoplastic carbon fiber woven cloth and stainless steel ultra-thin tape have 4 to 12 layers.

[0014] Furthermore, the inner lining layer is made of polyolefin materials including polypropylene (PP), high-density polyethylene (HDPE), low-density polyethylene (LDPE), ultra-high molecular weight polyethylene (UHMW-PE), etc.; the inner lining layer can select different polyolefin materials according to different transportation materials, and can also add appropriate additives according to needs, such as antioxidants (0.1% to 0.5%), anti-seepage agents (1% to 5%), plasticizers (1% to 5%), heat stabilizers (0.05% to 0.3%), antistatic agents (0.1% to 0.5%), flame retardants (10% to 12%), foaming agents (1% to 5%), fillers (10% to 50%), etc.;

[0015] Furthermore, the polyethylene materials used in the outer protective layer include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), etc.; different polyethylene materials can be selected for the outer protective layer according to the use environment of the pipeline; and appropriate additives can be added according to needs, such as antioxidants (0.1% to 0.5%), toughening agents (5% to 20%), stearic acid (0.1% to 0.5%), heat stabilizers (0.05% to 0.3%), antistatic agents (0.1% to 0.5%), flame retardants (10% to 12%), ultraviolet absorbers (0.1% to 1%), foaming agents (1% to 5%), fillers (10% to 50%), etc.

[0016] The production process of carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe includes the following steps:

[0017] Step 1, preparing an inner lining layer; determining the thickness of the inner lining layer according to application requirements, extruding it onto a mold pipe through an inner layer extruder, and then passing through a vacuum sizing box to fit the inner layer material to the mold to obtain the inner lining layer;

[0018] Step 2, preparing a carbon fiber / stainless steel ultra-thin tape composite tape; determining the width, number of layers and ply order of the thermoplastic carbon fiber woven cloth and the stainless steel ultra-thin tape according to the product strength requirements, spraying the silane coupling agent evenly on the surface of the stainless steel ultra-thin tape using a sprayer, and then rolling the multiple layers of carbon fiber woven cloth and the stainless steel ultra-thin tape together through a two-roll mill in an infrared high-temperature environment box to form a carbon fiber / stainless steel ultra-thin tape composite tape;

[0019] Step 3, winding the carbon fiber / stainless steel ultra-thin tape composite tape; winding the carbon fiber / stainless steel ultra-thin tape composite tape onto the inner lining layer in two winding modes, namely, spiral winding and hoop winding, by an automatic winding machine in an infrared high-temperature environment box; and then rolling the fiber metal composite tape and the inner lining layer tightly by two rollers;

[0020] Step 4, preparing an outer protective layer; extruding the outer protective layer material onto the reinforcing layer through an outer layer extruder, and then vacuum shaping it through a vacuum sizing box to make the three-layer structure fit tightly;

[0021] Step 5, cooling the pipeline; cooling the vacuum-formed flexible pipe through a cooling spray box to quickly cool and solidify the pipe;

[0022] Step 6, cutting to length and collecting; the cooled flexible pipe is pulled to the fixed-length cutting machine through a traction machine, and cut into specified lengths according to product requirements to obtain a finished fiber metal composite reinforced flexible pipe.

[0023] Furthermore, the extrusion temperature of the inner lining layer is 160° C. to 230° C.; the extrusion temperature of the outer protective layer is 160° C. to 230° C. The mold mandrels of different diameters can be replaced according to the product size requirements.

[0024] Furthermore, the volume ratio of the silane coupling agent is anhydrous ethanol: distilled water: silane coupling agent (KH-550) = 90:9:1.

[0025] Furthermore, the temperature of the infrared environment box in step 2 and step 3 is set at 120° C., which can quickly soften the thermoplastic carbon fiber prepreg.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The present invention provides a flexible fiber metal composite reinforced pipe and its production process, which solves the problem of high transportation and installation costs of traditional flexible pipes. Compared with traditional metal pipes and metal reinforced flexible pipes, the flexible composite pipe has achieved greater lightness while ensuring good structural strength. It can reduce weight by 60% to 80% compared with traditional metal pipes of the same specifications, and can reduce weight by 20% to 40% compared with metal reinforced flexible pipes of the same specifications.

[0028] At the same time, the process can also change the materials or additives of the inner lining layer and the outer protective layer so that the flexible pipe can be applied to different use environments, and can also meet product requirements of different specifications by changing the material thickness and changing the mold size. The production process of the flexible composite pipe of the present invention is simple and can achieve continuous processing, greatly improving production efficiency. The production process provided by the present invention enables the flexible fiber metal composite reinforced pipe to be widely used in the fields of oil and gas transportation, aerospace, construction, etc., realizes the lightweight of structural materials, reduces the operation and installation costs of the pipeline, and is of great significance to energy conservation and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is an axial cross-sectional view of a fiber metal composite reinforced flexible pipe;

[0030] Figure 2 Schematic diagram of the process for preparing carbon fiber and stainless steel ultra-thin strip composite tape;

[0031] Figure 3 This is a simplified diagram of the process route for preparing fiber metal composite reinforced flexible pipes.

[0032] Among them, 1. inner lining layer; 2. carbon fiber / stainless steel ultra-thin belt composite reinforcement layer; 3. outer protective layer; 4. stainless steel ultra-thin belt; 5. carbon fiber woven cloth; 6. silane coupling agent sprayer; 7. two-roll mill; 8. carbon fiber / stainless steel ultra-thin belt composite belt; 9. mold mandrel; 10. inner layer extruder; 11. vacuum sizing box; 12. automatic winding machine; 13. roller press; 14. infrared high temperature environment box; 15. outer layer extruder; 16. cooling spray box; 17. fixed-length cutting machine; 18. fiber metal composite reinforced flexible pipe finished product. DETAILED DESCRIPTION

[0033] In order to gain a deeper understanding of the present invention, we will provide a comprehensive and detailed description of the present invention. However, the present invention has multiple implementations and is not limited to the specific examples listed herein. The presentation of these examples is intended to deepen the comprehensive understanding of the disclosure of the present invention.

[0034] Example 1

[0035] A production process of a high-performance small-diameter carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe that is resistant to chemical corrosion and high temperature, the specific steps are as follows:

[0036] Step 1: Prepare the inner lining. According to the application requirements, the thickness of the inner lining is determined to be 2mm, and the inner lining material is selected from polypropylene (PP) that is resistant to chemical corrosion, has good heat resistance and has a low density. In order to improve the strength of the inner lining and extend the service life of the inner lining, the following additives are added to the inner lining: antioxidant (0.1% to 0.5%), impermeability agent (1% to 5%), heat stabilizer (0.05% to 0.3%), antistatic agent (0.1% to 0.5%), flame retardant (10% to 12%), foaming agent (1% to 5%). The proportion of additives can be determined according to the use requirements. After mixing PP and the above-mentioned additives, the inner lining material is extruded onto the mold pipe through the inner layer extruder, and the extrusion temperature is 160℃ to 230℃. Then the inner layer material is fitted and shaped with the mold through a vacuum sizing box to obtain the inner lining.

[0037] Step 2: Prepare carbon fiber / stainless steel ultra-thin tape composite tape. According to the product strength requirements, the carbon fiber woven cloth is determined to be a thermoplastic epoxy resin matrix carbon fiber woven cloth prepreg with a width of 20mm and a thickness of 150μm. The ultra-thin stainless steel tape has a width of 20mm and a thickness of 150μm. Use a sprayer to evenly spray the silane coupling agent (anhydrous ethanol: distilled water: silane coupling agent (KH-550) = 90:9:1) on the surface of the stainless steel ultra-thin tape. Then, use a two-roll mill to press the multi-layer carbon fiber woven cloth and the stainless steel ultra-thin tape in a 120°C infrared high temperature environment box. Figure 2 The ply structure shown is rolled together to form a carbon fiber / stainless steel ultra-thin tape composite tape.

[0038] Step 3: Winding the carbon fiber / stainless steel ultra-thin tape composite tape. In an infrared high-temperature environment box, the carbon fiber / stainless steel ultra-thin tape composite tape is wound onto the inner lining layer by an automatic winding machine in two winding methods: ±53° spiral winding (2 layers) and 80°~90° hoop winding (2 layers). Then, the fiber metal composite tape and the inner lining layer are rolled and compacted by two rollers.

[0039] Step 4: Prepare the outer protective layer. The thickness of the outer protective layer is 2mm. It uses high-density polyethylene (HDPE) with high heat resistance, wear resistance and high strength. According to the product's requirements for chemical corrosion resistance and high temperature resistance, the following additives are added: antioxidant (0.1% to 0.5%), heat stabilizer (0.05% to 0.3%), antistatic agent (0.1% to 0.5%), flame retardant (10% to 12%), foaming agent (1% to 5%), filler (10% to 50%). The proportion of additives can be determined according to usage requirements. After mixing HDPE and the above additives, extrude them onto the reinforcement layer through an outer layer extruder at an extrusion temperature of 160°C to 230°C, and then vacuum sizing is performed in a vacuum sizing box to make the three-layer structure fit tightly.

[0040] Step 5: Cooling the pipe. The vacuum-formed flexible pipe is cooled by a cooling spray box to quickly cool down and solidify the pipe.

[0041] Step 6: Cut to length and collect. The cooled flexible pipe is pulled to the fixed-length cutting machine by a traction machine, and cut into specified lengths according to product requirements to obtain a small-diameter carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe product.

[0042] Example 2

[0043] A production process of a high-performance large-diameter carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe that is resistant to ultraviolet high temperature, low temperature, wear and aging, and the specific steps are as follows:

[0044] Step 1: Prepare the inner lining. According to the application requirements, the thickness of the inner lining is determined to be 6mm, and the inner lining material is selected from high-density polyethylene (HDPE) with high strength, good wear resistance, good heat resistance and low density. In order to improve the processability and service life of the inner lining, the following additives are added to the inner lining: antioxidant (0.1%~0.5%), plasticizer (1%~5%), heat stabilizer (0.05%~0.3%), foaming agent (1%~5%), filler (10%~50%), and the proportion of additives can be determined according to the use requirements. After mixing HDPE and the above additives, the inner lining material is extruded onto the mold pipe through the inner layer extruder, and the extrusion temperature is 160℃~230℃. Then the inner layer material is fitted and shaped with the mold through a vacuum sizing box to obtain the inner lining.

[0045] Step 2: Prepare carbon fiber / stainless steel ultra-thin tape composite tape. According to the product strength requirements, the carbon fiber woven cloth is determined to be a thermoplastic epoxy resin matrix carbon fiber woven cloth prepreg with a width of 100mm and a thickness of 150μm. The ultra-thin stainless steel tape has a width of 100mm and a thickness of 150μm. Use a sprayer to evenly spray the silane coupling agent (anhydrous ethanol: distilled water: silane coupling agent (KH-550) = 90:9:1) on the surface of the stainless steel ultra-thin tape. Then, use a two-roll mill to press the multi-layer carbon fiber woven cloth and the stainless steel ultra-thin tape in an infrared high-temperature environment box at 120°C. Figure 2 The ply structure shown is rolled together to form a carbon fiber / stainless steel ultra-thin tape composite tape.

[0046] Step 3: Winding the carbon fiber / stainless steel ultra-thin tape composite tape. In an infrared high-temperature environment box, the carbon fiber / stainless steel ultra-thin tape composite tape is wound onto the inner lining layer by an automatic winding machine in two winding methods: ±53° spiral winding (6 layers) and 80°~90° hoop winding (6 layers). Then, the fiber metal composite tape and the inner lining layer are rolled and compacted by two rollers.

[0047] Step 4: Prepare the outer protective layer. The thickness of the outer protective layer is 6mm. It uses linear low-density polyethylene (LLDPE) with high strength, high heat resistance and cold resistance, and light weight. According to the product's requirements for ultraviolet high temperature resistance, low temperature resistance, wear resistance, and aging resistance, the following additives are added: antioxidant (0.1% to 0.5%), toughening agent (5% to 20%), heat stabilizer (0.05% to 0.3%), antistatic agent (0.1% to 0.5%), ultraviolet absorber (0.1% to 1%), foaming agent (1% to 5%), filler (10% to 50%). The proportion of additives can be determined according to usage requirements. After mixing LLDPE and the above additives, extrude them onto the reinforcement layer through the outer layer extruder. The extrusion temperature is 160℃ to 230℃, and then vacuum shaped by a vacuum sizing box to make the three-layer structure fit tightly.

[0048] Step 5: Cooling the pipe. The vacuum-formed flexible pipe is cooled by a cooling spray box to quickly cool down and solidify the pipe.

[0049] Step 6: Cut to length and collect. The cooled flexible pipe is pulled to the fixed-length cutting machine by a traction machine, and cut into specified lengths according to product requirements to obtain a large-diameter carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe finished product.

[0050] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. Although the illustrative specific embodiments of the present invention are described above to facilitate the understanding of the present invention by the technical personnel in the field, it should be clear that the present invention is not limited to the scope of the specific embodiments. For the ordinary technical personnel in the field, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe, characterized in that: The flexible pipe is composed of an inner lining layer, a fiber metal composite reinforcement layer, and an outer protective layer from inside to outside; The inner lining layer is made of polyolefin material; The fiber metal composite reinforcement layer is prepared by winding a fiber metal composite tape formed by alternately compounding thermoplastic carbon fiber woven cloth and stainless steel ultra-thin tape on the inner layer by spiral winding and hoop winding; The outer protective layer is made of polyethylene material.

2. The carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 1, characterized in that: The inner diameter of the flexible pipe is 50-400 mm, and the thickness is 6-18 mm; wherein the thickness of the inner lining layer is 2-6 mm, the thickness of the fiber metal composite reinforcement layer is 2-6 mm, and the thickness of the outer protective layer is 2-6 mm.

3. The carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 1, characterized in that: The thermoplastic carbon fiber woven cloth adopts thermoplastic epoxy resin matrix carbon fiber woven cloth prepreg, with a width of 20 to 100 mm and a thickness of 150 μm; the stainless steel ultra-thin strip has a width of 20 to 100 mm and a thickness of 150 μm; the fiber metal composite strip has a width of 20 to 100 mm.

4. The carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 1, characterized in that: The spiral winding method of the composite tape has a winding angle of ±53° and a winding number of 2 to 6 layers; the circumferential winding angle is 80° to 90° and a winding number of 2 to 6 layers; the thermoplastic carbon fiber woven cloth and the stainless steel ultra-thin tape have 4 to 12 layers.

5. The carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 1, characterized in that: The inner lining layer is made of polyolefin materials including polypropylene, high-density polyethylene, low-density polyethylene and ultra-high molecular weight polyethylene.

6. The carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 1, characterized in that: The polyethylene material includes high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene.

7. The production process of the carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1, preparing an inner lining layer; determining the thickness of the inner lining layer according to application requirements, extruding it onto a mold pipe through an inner layer extruder, and then passing through a vacuum sizing box to fit the inner layer material to the mold to obtain the inner lining layer; Step 2, preparing a carbon fiber / stainless steel ultra-thin tape composite tape; determining the width, number of layers and ply order of the thermoplastic carbon fiber woven cloth and the stainless steel ultra-thin tape according to the product strength requirements, spraying the silane coupling agent evenly on the surface of the stainless steel ultra-thin tape using a sprayer, and then rolling the multiple layers of carbon fiber woven cloth and the stainless steel ultra-thin tape together through a two-roll mill in an infrared high-temperature environment box to form a carbon fiber / stainless steel ultra-thin tape composite tape; Step 3, winding the carbon fiber / stainless steel ultra-thin tape composite tape; winding the carbon fiber / stainless steel ultra-thin tape composite tape onto the inner lining layer in two winding modes, namely, spiral winding and hoop winding, by an automatic winding machine in an infrared high-temperature environment box; and then rolling the fiber metal composite tape and the inner lining layer tightly by two rollers; Step 4, preparing an outer protective layer; extruding the outer protective layer material onto the reinforcing layer through an outer layer extruder, and then vacuum shaping it through a vacuum sizing box to make the three-layer structure fit tightly; Step 5, cooling the pipeline; cooling the vacuum-formed flexible pipe through a cooling spray box to quickly cool and solidify the pipe; Step 6, cutting to length and collecting; the cooled flexible pipe is pulled to the fixed-length cutting machine through a traction machine, and cut into specified lengths according to product requirements to obtain a finished fiber metal composite reinforced flexible pipe.

8. The production process of carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 7, characterized in that: The extrusion temperature of the inner lining layer is 160°C to 230°C; the extrusion temperature of the outer protective layer is 160°C to 230°C.

9. The production process of carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 7, characterized in that: The volume ratio of the silane coupling agent is anhydrous ethanol: distilled water: silane coupling agent = 90:9:

1.

10. The production process of carbon fiber / stainless steel ultra-thin strip composite reinforced flexible pipe according to claim 7, characterized in that: The temperature of the infrared environmental chamber described in step 2 and step 3 was set at 120°C.

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