CN116293103A - Composite pipe and preparation method thereof - Google Patents

Abstract

The invention discloses a composite pipe, which sequentially includes an inner core pipe, a copper-plated steel wire, a pre-impregnated fiber tape and an outer protective pipe from the inside to the outside; Fully pre-impregnated with high-performance bonding resin. The invention also discloses a preparation method of a composite pipe, which includes: (1) extruding the raw material of the inner core pipe, vacuum cooling and sizing; (2) coating the copper-plated steel wire with high-performance adhesive resin at high speed, and winding it; ( 3) The pre-impregnated fiber tape is fully pre-impregnated with high-performance adhesive resin, and wound; (4) The outer protective tube extruded through the connecting layer composite die and the outer protective tube composite die forms the final composite structure, vacuum cooling and sizing , cutting, sealing, trimming, that is. The present invention adopts the double-reinforcement material multi-layer composite combining steel mesh skeleton reinforcement and pre-impregnated fiber tape stiffening reinforcement, which improves the blasting test pressure and ring stiffness of the composite pipe, and avoids the pipeline bearing caused by the single reinforcement manufacturing. pressure defect.

Description

A kind of composite pipe material and preparation method thereof

technical field

The invention relates to the technical field of composite pipes, in particular to a composite pipe and a preparation method thereof.

Background technique

Composite pipes are pipes based on metal and thermoplastic composite structures, lined with non-metallic materials such as plastic polypropylene (PP), polyethylene (PE) or externally welded cross-linked polyethylene, and have the characteristics of metal pipes and non-metal pipes. Double advantage.

At present, most of the existing composite pipes on the market are steel-plastic reinforced polyethylene composite pipes and fiber-reinforced composite pipes. These two products are different in terms of composite methods and product performance.

Chinese invention patent CN 112096973 A discloses a steel mesh skeleton reinforced polypropylene composite pipe and its preparation method and application. From the inside to the outside, there are polypropylene core pipe, steel wire reinforcement layer, first adhesive resin layer, and second adhesive resin layer. The resin layer and the outer layer of polyethylene solve the problems of high low-temperature brittleness of the pipe material using polypropylene alone as the matrix and poor heat resistance when using polyethylene alone as the matrix. However, this kind of steel-plastic reinforced composite pipe has the following disadvantages: 1. In the application and production of large diameter and higher pressure (3.0-3.5MPa), there are common problems such as unreasonable structural design and difficult production control technology. 4-layer steel wire is used for multiple molding in the industrial press, and the quality uniformity of the pipe is poor; 2. The multi-layer composite steel wire design is adopted, with high meter weight and large consumables; 3. The mesh spacing of the steel wire mesh is unevenly distributed, and the structure is unstable. Where the steel wire spacing is large, the local strength of the pipe is low; 4. The ring stiffness of the pipe is low, and it is easy to produce axial deformation; 5. There are joints in the winding of each layer of steel wire, which directly contact the outer wall of PE. The metal wire is easy to corrode when exposed to water.

Chinese invention patent CN 115431575 A discloses a continuously produced narrow-band structural fiber-reinforced plastic composite pipe and its manufacturing method. According to the overall production process route, it is divided into core tube extrusion-core tube cooling forming-reinforced fiber winding-outer layer The main process route of extrusion compounding-cooling-cutting-sealing enables the continuity of fiber pressure bearing to be maintained during the process of replacing the used fiber reinforced layer of the pipeline, and the pressure bearing effect of the pipeline is guaranteed. However, this type of fiber-reinforced composite pipe has the following disadvantages: 1. The product has insufficient rigidity and is easily deformed; 2. The interlayer shear strength is low.

Therefore, how to develop a new type of stiffened and reinforced composite pipe is an urgent problem to be solved by those skilled in the art.

Contents of the invention

In view of this, the object of the present invention is to provide a composite pipe and its preparation method to solve the deficiencies in the prior art.

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

A composite pipe, which includes an inner core pipe, copper-plated steel wire, pre-impregnated fiber tape and outer protective pipe from the inside to the outside; and the copper-plated steel wire is coated with high-performance adhesive resin at high speed, and the pre-impregnated fiber tape is coated with high-performance adhesive Fully pre-impregnated with resin.

Further, the above-mentioned inner core tube and outer protective tube are made of bimodal high-density polyethylene resin of PE100 grade or above.

The beneficial effect of adopting the above further technical solution is that the molecular weight distribution of ordinary polyethylene has only one peak, while the molecular weight distribution curve of bimodal polyethylene presents two peaks. Because the processability and mechanical properties of polyethylene resin are contradictory, increasing the molecular weight can make the product have better mechanical properties, but at the same time it becomes difficult to process, and bimodal polyethylene can solve this problem well. The bimodal polyethylene product selected in the present invention is composed of high molecular weight polyethylene and low molecular weight polyethylene, wherein the high molecular weight polyethylene is used to ensure physical and mechanical strength, and the low molecular weight polyethylene is used to improve processing performance.

Furthermore, the material of the above-mentioned copper-coated steel wire is high-carbon copper-coated steel wire, the carbon content is 0.6%-0.8%, preferably 0.7%, the coating material is brass or tin bronze, and the diameter is 0.6-1.4mm.

The beneficial effect of adopting the above-mentioned further technical solution is that by coating the steel wire with a carbon content of 0.6%-0.8% copper plating, the bonding performance between the steel wire and the high-performance adhesive resin can be enhanced, and it has a certain anti-corrosion effect.

Furthermore, the above-mentioned prepreg fiber tape is made of at least one of glass fiber, aramid fiber and polyester fiber; preferably glass fiber.

The beneficial effect of adopting the above further technical solution is that the prepreg fiber tape is a structural composite tape composed of thermoplastic resin matrix, glass fiber and some auxiliary agents. The glass fiber selected in the present invention is rich in raw materials, low in cost and high in strength, and is a good reinforcing material. Glass fiber is resistant to high temperature (680°C), non-combustible, anti-corrosion, good heat insulation, sound insulation, high tensile strength, good electrical insulation, and the cold and hot cycle test shows that the material has good low temperature resistance and can meet low temperature conditions Under the construction and operation needs.

Further, the winding directions of the copper-coated steel wire and the prepreg fiber tape are both left-handed and right-handed, and the winding angles are both 54.7°-60°.

The beneficial effect of adopting the above further technical solution is that the winding direction is left-handed and right-handed, so that the composite structure can be formed between the copper-plated steel wire and the prepreg fiber tape without welding, thereby greatly improving the production efficiency. In addition, the composite pipe is designed according to the horizontal force state, and the winding angle of the reinforcement layer is 54.7°-60°, which can make the axial and circumferential force of the composite pipe uniform, maintain the balance of the bearing capacity, and thus maximize the bearing capacity .

Furthermore, the above-mentioned high-performance adhesive resin is a high-density polyethylene resin grafted with maleic anhydride.

The beneficial effect of adopting the above-mentioned further technical scheme is that the high-density polyethylene resin selected by the maleic anhydride graft modification of the present invention can make the inner core pipe, the copper-plated steel wire, the prepreg fiber tape and the outer protective pipe tightly bonded Together, so as to be able to carry collaboratively.

A preparation method of the above-mentioned composite pipe, specifically comprising the following steps:

(1) Extrude the inner core tube raw material, vacuum cooling and sizing, to obtain the inner core tube;

(2) Copper-plated steel wire is coated with high-performance adhesive resin at high speed, and then double-layer cross-wound on the inner core tube;

(3) The pre-impregnated fiber tape is fully pre-impregnated with high-performance adhesive resin, and then wound on the copper-plated steel wire;

(4) The final composite structure is formed by extruding the outer protective tube through the connecting layer composite die head and the outer protective tube composite die head, vacuum cooling and sizing, cutting, sealing, and repairing to obtain a composite pipe.

Further, the above step (2) also includes: heating the inner core tube wound with the copper-coated steel wire through a far-infrared heating box.

The beneficial effect of adopting the above further technical solution is that, by heating, the high-performance adhesive resin on the copper-plated steel wire can be partially melted, so that it can be closely bonded to the inner core tube.

Further, the above step (3) also includes: heating the inner core tube wound with the copper-plated steel wire and the prepreg fiber tape through a far-infrared heating box, and then air-cooling through an air-cooling ring.

The beneficial effect of adopting the above further technical solution is that, by heating, the high-performance adhesive resin on the prepreg fiber tape can be partially melted, so as to be closely bonded to the copper-plated steel wire; by air cooling, a double-reinforced rigid composite layer can be formed .

Further, in the above step (4), the sealing material is consistent with that of the inner core tube and the outer protective tube, and is sealed by a special hot-melt butt joint sealing machine.

The beneficial effect of adopting the above-mentioned further technical solution is that due to the reinforcing characteristics of the copper-plated steel wire and the prepreg fiber tape in the composite pipe, the end face of the composite pipe has reinforced external leakage after production and cutting. Synergy that guarantees long-term service life.

Via the above-mentioned technical scheme, it can be seen that compared with the prior art, the beneficial effects of the present invention are as follows:

1. The present invention discloses a new type of prepreg fiber tape double rigidity reinforced steel mesh skeleton polyethylene composite pipe that can be continuously produced, including a base pipe (inner core pipe and outer protective pipe) extruded with high-density polyethylene resin ), high-strength copper-plated steel wire cross-helical winding formed steel mesh skeleton reinforcement and pre-impregnated fiber tape winding forming rigid reinforcement, and high-performance bonding hot-melt adhesive is selected to combine steel mesh skeleton reinforcement, pre-impregnated fiber The reinforced body with rigidity is tightly welded with the inner and outer layers (inner core tube and outer protective tube) of the polyethylene composite pipe to form a four-in-one new type of reinforced composite pipe with rigidity.

2. The present invention achieves multi-layer compounding through copper-plated steel wire, new prepreg fiber tape and polyethylene material, aiming to solve the bottleneck breakthrough of production and application technology, realize the disruptive innovation breakthrough of this new pipeline product, and improve product quality and economic benefits The improvement and breakthrough of the polyethylene composite pipe can achieve the goal of improving the pressure resistance, improving the ring stiffness and reducing the material cost.

3. The material of the composite pipe of the present invention can be adjusted according to the operating conditions and functional requirements, so as to expand the application conditions and fields of the product.

4. The present invention adopts the double-reinforcement material multi-layer composite of steel mesh skeleton reinforcement and prepreg fiber tape stiffening reinforcement, which improves the burst test pressure and ring stiffness of the composite pipe, and avoids the failure caused by the manufacture of a single reinforcement. Piping pressure defects.

5. The present invention adopts the continuous production of pre-impregnated fiber-reinforced composite pipes with excellent performance, one-step molding, and improves production efficiency.

Detailed ways

The following clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

Composite pipes, including inner core pipe, copper-plated steel wire, pre-impregnated fiber tape and outer protective pipe from the inside to the outside; and the copper-plated steel wire is coated with high-performance adhesive resin at high speed, and the pre-impregnated fiber tape is coated with high-performance adhesive resin Fully presoaked;

Among them, the inner core tube and the outer protective tube are made of PE100 bimodal high-density polyethylene resin;

The material of the copper-plated steel wire is high-carbon copper-plated steel wire, the carbon content is 0.6%, the coating material is brass, and the diameter is 0.6mm;

The material of the prepreg fiber tape is aramid fiber;

The winding direction of the prepreg fiber tape is left-handed and right-handed, and the winding angle is 54.7°;

The high-performance adhesive resin is a high-density polyethylene resin grafted with maleic anhydride;

The preparation method of the above-mentioned composite pipe specifically comprises the following steps:

(1) Extrude the inner core tube raw material, vacuum cooling and sizing, to obtain the inner core tube;

(2) Copper-plated steel wire is coated with high-performance adhesive resin at high speed, and wound on the steel wire ingot for production; when the formed inner core tube passes through the wire winding machine, the two turntables of the winding machine rotate left and right respectively. Rotate, and adjust the winding angle of the steel wire to 54.7° by adjusting the restraint device on the winding machine, so that the copper-coated steel wire is evenly double-layered and cross-wound on the inner core tube, and finally heated by the far-infrared heating box;

(3) The pre-impregnated fiber tape is fully pre-impregnated with high-performance adhesive resin, the winding direction is adjusted to be left-handed and right-handed, and the winding angle is 54.7°, so that the pre-impregnated fiber tape is evenly wound on the copper-plated steel wire, and the far-infrared The heating box is used for heating, and then the air-cooled ring is used for air-cooling to form a double-reinforced and stiffened composite layer;

(4) The outer protective tube extruded through the connecting layer composite die and the outer protective tube composite die forms the final composite structure, vacuum cooling, sizing, cutting, PE100 bimodal high-density polyethylene resin and special hot-melt butt joint The sealing machine is used for sealing and repairing, and the composite pipe is obtained.

Example 2

Composite pipes, including inner core pipe, copper-plated steel wire, pre-impregnated fiber tape and outer protective pipe from the inside to the outside; and the copper-plated steel wire is coated with high-performance adhesive resin at high speed, and the pre-impregnated fiber tape is coated with high-performance adhesive resin Fully presoaked;

Among them, the inner core tube and the outer protective tube are made of PE100 bimodal high-density polyethylene resin;

The material of the copper-plated steel wire is high-carbon copper-plated steel wire, the carbon content is 0.7%, the coating material is brass, and the diameter is 1.0mm;

The material of the prepreg fiber tape is glass fiber;

The winding direction of the prepreg fiber tape is left-handed and right-handed, and the winding angle is 58°;

The high-performance adhesive resin is a high-density polyethylene resin grafted with maleic anhydride;

The preparation method of the above-mentioned composite pipe specifically comprises the following steps:

(1) Extrude the inner core tube raw material, vacuum cooling and sizing, to obtain the inner core tube;

(2) Copper-plated steel wire is coated with high-performance adhesive resin at high speed, and wound on the steel wire ingot for production; when the formed inner core tube passes through the wire winding machine, the two turntables of the winding machine rotate left and right respectively. Rotate, and adjust the winding angle of the steel wire to 58° by adjusting the restraint device on the winding machine, so that the copper-coated steel wire is evenly double-layered and cross-wound on the inner core tube, and finally heated by a far-infrared heating box;

(3) Fully impregnate the pre-impregnated fiber tape with high-performance adhesive resin, adjust the winding direction to be left-handed and right-handed, and the winding angle is 58°, so that the pre-impregnated fiber tape is evenly wound on the copper-plated steel wire, and the far-infrared The heating box is used for heating, and then the air-cooled ring is used for air-cooling to form a double-reinforced and stiffened composite layer;

(4) The outer protective tube extruded through the connecting layer composite die and the outer protective tube composite die forms the final composite structure, vacuum cooling, sizing, cutting, PE100 bimodal high-density polyethylene resin and special hot-melt butt joint The sealing machine is used for sealing and repairing, and the composite pipe is obtained.

Example 3

Composite pipes, including inner core pipe, copper-plated steel wire, pre-impregnated fiber tape and outer protective pipe from the inside to the outside; and the copper-plated steel wire is coated with high-performance adhesive resin at high speed, and the pre-impregnated fiber tape is coated with high-performance adhesive resin Fully presoaked;

Among them, the inner core tube and the outer protective tube are made of PE100 bimodal high-density polyethylene resin;

The material of the copper-plated steel wire is high-carbon copper-plated steel wire, the carbon content is 0.8%, the coating material is tin bronze, and the diameter is 1.4mm;

The material of the prepreg fiber tape is polyester fiber;

The winding direction of the prepreg fiber tape is left-handed and right-handed, and the winding angle is 60°;

The high-performance adhesive resin is a high-density polyethylene resin grafted with maleic anhydride;

The preparation method of the above-mentioned composite pipe specifically comprises the following steps:

(1) Extrude the inner core tube raw material, vacuum cooling and sizing, to obtain the inner core tube;

(2) Copper-plated steel wire is coated with high-performance adhesive resin at high speed, and wound on the steel wire ingot for production; when the formed inner core tube passes through the wire winding machine, the two turntables of the winding machine rotate left and right respectively. Rotate, and adjust the winding angle of the steel wire to 60° by adjusting the restraint device on the winding machine, so that the copper-coated steel wire is evenly double-layered and cross-wound on the inner core tube, and finally heated by the far-infrared heating box;

(3) Fully impregnate the pre-impregnated fiber tape with high-performance adhesive resin, adjust the winding direction to be left-handed and right-handed, and the winding angle is 60°, so that the pre-impregnated fiber tape is evenly wound on the copper-plated steel wire, and the far-infrared The heating box is used for heating, and then the air-cooled ring is used for air-cooling to form a double-reinforced and stiffened composite layer;

(4) The outer protective tube extruded through the connecting layer composite die and the outer protective tube composite die forms the final composite structure, vacuum cooling, sizing, cutting, PE100 bimodal high-density polyethylene resin and special hot-melt butt joint The sealing machine is used for sealing and repairing, and the composite pipe is obtained.

Comparative example 1

Only use PE100 grade bimodal high-density polyethylene resin as raw material to make PE100 grade solid wall pipe.

Comparative example 2

The only difference from Example 2 is that no pre-impregnated fiber tape is selected, and step (3) is not included to obtain a steel wire mesh polyethylene composite pipe.

Comparative example 3

The only difference from Example 2 is that the copper-coated steel wire is not selected, and the step (2) is not included to obtain a continuous glass fiber tape reinforced polyethylene composite pipe.

Comparative example 4

The only difference from Example 2 is that polypropylene is used as the material of the inner core tube instead of pre-impregnated fiber tape, and step (3) is not included to obtain a steel wire mesh polyethylene composite pipe.

Performance Testing

Each get the pipe material that embodiment 2 and comparative example 1-4 make, carry out following performance test respectively:

1. Test the peel strength of the pipe according to CJ/T189 and GB/T32439-2015;

2. According to CJ/T189 and GB/T32439-2015 test pipe burst pressure test;

3. According to CJ/T189 and GB/T32439-2015, test the 20℃, 2PN, 1h hydrostatic test of the pipe;

4. According to GB/T32439-2015, test the 60℃, 1.2PN, 165h hydrostatic test of the pipe;

5. According to GB/T32439-2015, test the 60℃, 1.1PN, 1000h hydrostatic test of the pipe;

6. According to CJ/T189 and GB/T32439-2015, test the pressure cracking stability test of pipes;

7. After placing the pipe at a constant temperature of -20°C for 24 hours, use a 3kg weight to perform a drop hammer impact test on the pipe;

8. Use two flat plates parallel to each other to flatten a section of horizontally placed pipe in the vertical direction at a constant rate to obtain the load-deformation relationship curve, and calculate the test ring with the load when the deformation in the diameter direction of the pipe is 3%. stiffness.

Taking 160*3.5MPa as an example, the comparison results of the main performance test data of the pipes of Example 2 and Comparative Examples 1-4 are shown in Table 1.

Table 1 embodiment 2 and comparative example 1-4 pipe main performance test data comparison result

It can be seen from Table 1 that, compared with Examples 1-4, the main properties of the composite pipe in Example 2 of the present invention are significantly improved.

The above test shows that the present invention adopts the double-reinforcement material multi-layer composite of the steel mesh skeleton reinforcement and the prepreg fiber tape stiffening reinforcement, which improves the burst test pressure and ring stiffness of the composite pipe, and avoids the need for a single reinforcement during manufacture. Caused by pipeline pressure defects.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. The composite pipe is characterized by sequentially comprising an inner core pipe, copper-plated steel wires, a prepreg fiber belt and an outer protective pipe from inside to outside;

and the copper-plated steel wire is coated with high-performance bonding resin at a high speed, and the prepreg fiber belt is fully prepreg with the high-performance bonding resin.

2. The composite pipe according to claim 1, wherein the inner core pipe and the outer protective pipe are made of bimodal high density polyethylene resin with PE100 grade or above.

3. The composite pipe according to claim 1, wherein the copper-plated steel wire is made of high-carbon copper-plated steel wire, the carbon content is 0.6% -0.8%, the plating material is brass or tin bronze, and the diameter is 0.6-1.4mm.

4. The composite tubing of claim 1, wherein the prepreg fiber tape is at least one of glass fiber, aramid fiber and polyester fiber.

5. The composite tubing of claim 1, wherein the copper plated steel wire and the prepreg fiber tape are wound in both left-handed and right-handed directions, and the winding angle is 54.7 ° -60 °.

6. The composite tubing of claim 1 wherein the high performance bonding resin is a maleic anhydride graft modified high density polyethylene resin.

7. A method for preparing the composite pipe according to claim 1, comprising the following steps:

(1) Extruding the raw material of the inner core pipe, and vacuum cooling and sizing to obtain the inner core pipe;

(2) Coating high-performance bonding resin on the copper-plated steel wire at a high speed, and then winding the copper-plated steel wire on the inner core pipe in a double-layer crossing manner;

(3) The method comprises the steps of comprehensively pre-soaking a pre-soaked fiber band with high-performance bonding resin, and then winding the pre-soaked fiber band on a copper-plated steel wire;

(4) And forming a final composite structure by the outer protective tube extruded by the connecting layer composite die head and the outer protective tube composite die head, vacuum cooling and sizing, cutting, sealing and repairing the mouth to obtain the composite pipe.

8. The method of producing a composite pipe according to claim 7, wherein step (2) further comprises: and heating the inner core pipe wound with the copper-plated steel wire through a far infrared heating box.

9. The method of producing a composite pipe according to claim 7, wherein step (3) further comprises: and heating the inner core pipe wound with the copper-plated steel wire and the prepreg fiber belt by a far infrared heating box, and then carrying out air cooling by an air cooling ring.

10. The method according to claim 7, wherein in the step (4), the material of the seal is the same as the material of the inner core tube and the outer protection tube, and the seal is performed by a special hot-melt butt-joint sealing machine.