CN115264185A

CN115264185A - Conductive flame-retardant sealing ring, composite metal framework pipe and processing technology thereof

Info

Publication number: CN115264185A
Application number: CN202210857846.1A
Authority: CN
Inventors: 徐冶锋
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-07-20
Filing date: 2022-07-20
Publication date: 2022-11-01

Abstract

The invention discloses a conductive flame-retardant sealing ring, a composite metal framework pipe and a processing technology thereof, and relates to the technical field of metal framework composite pipes. The composite metal framework pipe comprises a conductive sealing ring, and an inner layer pipe, an intermediate layer pipe and an outer layer pipe which are sequentially arranged from inside to outside, wherein a metal framework is arranged inside the inner layer pipe, and the end walls of the inner layer pipe, the intermediate layer pipe and the outer layer pipe are fixedly connected with the end wall of the conductive sealing ring. This application both can strengthen compound metal skeleton pipe and put into electrically conductive, antistatic and fire behaviour, can reduction in production cost again.

Description

Conductive flame-retardant sealing ring, composite metal framework pipe and processing technology thereof

Technical Field

The application relates to the technical field of metal framework composite pipes, in particular to a conductive flame-retardant sealing ring, a composite metal framework pipe and a processing technology thereof.

Background

The metal framework composite pipe is a novel pipe with a metal framework arranged inside a polymer core pipe, and has the characteristics of high rigidity and difficult deformation.

In the related art, a metal framework composite pipe is disclosed, which comprises a polymer layer, wherein a metal framework formed by winding steel wires in a crossed manner is arranged in the polymer layer. The polymer layer is formed by extruding high-elastic modulus plastic, and cross-linked polyethylene or non-cross-linked polyethylene special material is generally selected as the high-elastic modulus plastic. When the metal framework composite pipe is used for medium transportation, the electric conduction, antistatic and flame retardant properties of the metal framework composite pipe need to be enhanced. Therefore, in the production process, a master batch compounded by a high elastic modulus plastic and a functional additive is required to prepare the polymer layer.

In view of the above-mentioned related technologies, the inventor thinks that when producing the metal framework composite pipe, the master batch has the problems of difficult molding and high rejection rate due to the large viscosity, poor fluidity and large investment pressure.

Disclosure of Invention

In order to solve the problems that a composite metal framework pipe is difficult to form and has a high rejection rate, the application provides a conductive flame-retardant sealing ring, a composite metal framework pipe and a processing technology thereof.

In a first aspect, the present application provides a composite metal skeleton tube, which adopts the following technical scheme:

the utility model provides a composite metal skeleton pipe, includes that the electrically conductive ring that seals and from inside to outside sets gradually inlayer pipe, intermediate layer pipe and outer pipe, the inside of inlayer pipe is equipped with metal skeleton, the end wall of inlayer pipe, intermediate layer pipe and outer pipe all with the electrically conductive end wall fixed connection who seals the ring.

By adopting the technical scheme, the composite metal framework pipe adopts a multilayer structure, the inner layer pipe, the middle layer pipe, the outer layer pipe and the conductive sealing ring can be respectively prepared and then compounded into the integrated composite metal framework pipe, and the problems that the composite metal framework pipe is difficult to form and high in rejection rate are favorably solved. The metal framework is preferably a hollow tubular metal framework formed by winding and welding at least one steel wire on a plurality of uniformly distributed axial steel wires and arranging a gap between the wound steel wire and the axial steel wire after continuous winding and welding. The metal framework can also be a porous tubular metal framework which is formed by coiling and firmly welding butt seams and is provided with a plurality of geometric holes distributed on a steel plate.

In a specific possible embodiment, the conductive sealing ring, the inner tube, the middle tube and the outer tube all comprise high-elastic-modulus plastics, and the high-elastic-modulus plastics are polyethylene or polypropylene.

By adopting the technical scheme, the pipeline made of polyethylene or polypropylene has the characteristics of no odor and no toxicity, and also has the advantages of excellent low temperature resistance, good chemical stability, acid and alkali corrosion resistance, high temperature resistance and excellent electrical insulation.

In a specific embodiment, at least one of the conductive sealing ring, the inner tube, the middle tube and the outer tube further comprises fibers.

By adopting the technical scheme, the fiber is beneficial to enhancing the mechanical property of the pipeline and improving the tensile property and toughness of the pipeline.

In a specific possible embodiment, the inner tube and the conductive sealing ring are both layers made of conductive flame-retardant master batch, and the conductive flame-retardant master batch comprises the following raw materials in percentage by weight: 5-30% of conductive filler, 2-5% of antistatic agent, 3-6% of flame retardant and 59-90% of high-elasticity modulus plastic, wherein the surface resistance of the conductive flame-retardant master batch is less than 106 omega, the bending modulus is 700-1400MPa, and the conductive filler is at least one of conductive carbon black, carboxylated carbon nanotubes, multi-walled carbon nanotubes and carbon fibers.

By adopting the technical scheme, the conductive and flame-retardant master batch prepared from the raw materials is beneficial to improving the conductivity, antistatic performance and flame retardant performance of the composite metal framework pipe, and the conductive sealing ring is beneficial to connecting the inner layer pipe and the outer layer pipe, so that the inner layer pipe is electrically communicated with the outer layer pipe, and static electricity is conveniently conducted. Therefore, the composite metal framework pipe can enhance the performance of conductivity, static resistance and flame retardance of the composite metal framework pipe, and can reduce the production cost. Moreover, by adopting the raw material proportion, the surface resistance and the flexural modulus of the conductive flame-retardant master batch can be controlled within the range, the conductive flame-retardant master batch can have excellent conductive and antistatic properties and excellent mechanical properties, and the pipe made of the conductive flame-retardant master batch has higher ring stiffness and is beneficial to reducing the deformation of the composite metal framework pipe. The high elastic modulus plastic refers to polyethylene and/or polypropylene. The filler has good conductive performance, and is beneficial to improving the conductive performance and the antistatic performance of the conductive flame-retardant master batch. The conductive flame-retardant master batch adopting the conductive carbon black or the carboxylated carbon nanotube has more excellent conductive performance and antistatic performance.

In a specific possible embodiment, the antistatic agent is at least one of an organic antistatic agent and zinc oxide whiskers.

By adopting the technical scheme, both the organic antistatic agent and the zinc oxide whisker can improve the antistatic property of the conductive flame-retardant master batch, wherein the organic antistatic agent has better compatibility with high-elasticity modulus plastics and is beneficial to improving the uniformity of the conductive flame-retardant master batch; the zinc oxide whisker can also improve the rigidity of the conductive flame-retardant master batch.

In a specific possible embodiment, the outer layer pipe is made of an outer layer masterbatch, and the outer layer masterbatch comprises the following raw materials in parts by weight: 0.1-10% of carbon nano tube and 90.0-99.9% of high-elastic modulus plastic, wherein the outer layer master batch is prepared by the following steps: dispersing carbon nano tubes in water to obtain a dispersion liquid, crushing high-elasticity modulus plastic into powder, adding the powder into the dispersion liquid, uniformly dispersing, evaporating to remove water, and drying to obtain outer-layer tube powder; and melting the powder of the outer layer pipe, extruding and granulating to obtain an outer layer master batch.

By adopting the technical scheme, the carbon nano tube can enhance the conductivity and rigidity of the plastic with high elastic modulus, thereby being beneficial to improving the conductivity of the outer layer tube and reducing the deformation of the outer layer tube. By adopting the preparation steps, the carbon nano tube and the high-elasticity-modulus plastic can be mixed more uniformly, the ring stiffness of the outer-layer tube is further improved, and the deformation of the outer-layer tube is reduced.

In a specific possible embodiment, the interlayer tube is made of an interlayer masterbatch comprising the following raw materials in weight percent: 62 to 91 percent of high elastic modulus plastic, 5 to 30 percent of reinforced short fiber and 4 to 8 percent of surface treating agent; the intermediate layer master batch is prepared by the following steps: uniformly mixing the reinforced short fiber and the surface treating agent to obtain modified short fiber; and (3) melting and blending the modified short fibers and the conductive flame-retardant master batch, and then extruding and granulating to obtain the intermediate layer master batch, wherein the yield strength of the intermediate layer pipe is 22-35MPa.

By adopting the technical scheme, the reinforced short fiber can be inorganic fiber such as glass fiber and the like, and can also be organic fiber such as nylon fiber and the like, the surface treatment agent is firstly used for treating the reinforced short fiber, so that the reinforced short fiber is favorably connected with high-elasticity-modulus plastic, the ring stiffness of the middle-layer pipe is favorably improved, and the deformation of the middle-layer pipe is reduced; by adopting the raw material proportion and the preparation steps, the intermediate layer pipe within the yield strength range can be prepared, so that the intermediate layer pipe is not easy to deform.

In a second aspect, the present application provides a conductive sealing ring, which adopts the following technical scheme:

a conductive sealing ring is prepared by the following steps:

extruding or injection molding the conductive flame-retardant master batch to form an annular material, wherein the temperature of the extrusion or injection molding is 200-220 ℃, and the wall thickness of the annular material is greater than or equal to the sum of the wall thicknesses of the inner layer pipe, the middle layer pipe and the outer layer pipe;

when the conductive flame-retardant master batch is continuously extruded, the annular material is cut in sections to obtain the conductive sealing ring;

when the conductive flame-retardant master batch is injected into an annular material, the conductive sealing ring is directly obtained.

By adopting the technical scheme, the conductive sealing ring is made of the conductive flame-retardant master batch, so that the conductive sealing ring has excellent conductive, antistatic and flame-retardant properties, and can be well welded with the inner-layer pipe and the outer-layer pipe.

In a third aspect, the application provides a processing technology of a composite metal framework pipe, which adopts the following technical scheme: a processing technology of a composite metal framework pipe comprises the following steps:

s1, melting the conductive flame-retardant master batch, extruding the molten conductive flame-retardant master batch onto the outer surface and the inner surface of a metal framework, and co-extruding the molten conductive flame-retardant master batch into a pipe to obtain an inner layer pipe;

s2, heating the inner layer pipe, extruding the melted intermediate layer master batch onto the outer surface of the inner layer pipe, and co-extruding the master batch into a pipe to form the intermediate layer pipe;

s3, heating the middle layer pipe, extruding the outer layer master batch to the outer peripheral wall of the middle layer pipe after melting, and co-extruding to form a pipe material to form an outer layer pipe;

and S4, welding the conductive sealing ring on the end wall of the outer layer pipe, and simultaneously welding the end walls of the inner layer pipe and the middle layer pipe with the conductive sealing ring to obtain the composite metal framework pipe.

By adopting the technical scheme, the inner layer pipe, the middle layer pipe, the outer layer pipe and the conductive sealing ring are prepared in steps and then are compounded into a whole by means of co-extrusion or fusion welding and the like to obtain the composite metal framework pipe, so that the production difficulty of the composite metal framework pipe can be reduced, the rejection rate of the composite metal framework pipe is reduced, and the production cost is greatly reduced. The composite metal framework pipe prepared by the steps has high ring rigidity, is not easy to deform, and has strong conductive performance, antistatic performance and flame retardant performance.

In a specific possible embodiment, the extrusion temperatures in S1, S2, S3 and S4 are as follows: a first stage, 190-210 ℃; a second stage, 200-210 ℃; a third stage, 210-220 ℃; the fourth stage, 200-210 ℃; fifth stage, 200-210 deg.C.

By adopting the technical scheme and the extrusion temperature, the rejection rate of the composite metal framework pipe is reduced, and the production efficiency is improved.

In summary, the present application includes at least one of the following beneficial technical effects:

1. according to the composite metal framework pipe, the inner layer pipe, the middle layer pipe, the outer layer pipe and the conductive sealing ring are respectively prepared and then are compounded into the integral composite metal framework pipe, so that the problems that the composite metal framework pipe is difficult to form and high in rejection rate are solved;

2. the composite metal framework pipe has high ring stiffness, is not easy to deform, and has high conductive performance, antistatic performance and flame retardant performance;

3. the utility model provides a conductive seal ring, both had excellent electrically conductive, antistatic and flame retardant property, can be in the same place with the fine fuse of inlayer pipe and outer layer pipe again.

Drawings

Fig. 1 is a schematic view of the overall structure of a composite metal skeleton tube in example 1 of the present application.

Fig. 2 is a schematic diagram of the exploded structure of the composite metal skeleton tube in example 1 of the present application.

Description of reference numerals: 1. a conductive seal ring; 2. an inner layer tube; 3. a middle layer pipe; 4. an outer tube; 5. a metal skeleton.

Detailed Description

The present application is described in further detail below with reference to figures 1-2 and examples.

Examples

Example 1

The present embodiment provides a composite metal skeleton tube. Referring to fig. 1 and 2, including electrically conductive sealing ring 1, inlayer pipe 2, intermediate layer pipe 3 and outer pipe 4 set gradually from inside to outside, the periphery wall of inlayer pipe 2 bonds with the internal perisporium of intermediate layer pipe 3, the periphery wall of intermediate layer pipe 3 bonds with the internal perisporium of outer pipe 4, inlayer pipe 2 inside is equipped with metal framework 5, the metal framework 5 of this embodiment is by a steel wire winding welding on many evenly distributed's axial steel wire, after through continuous winding welding forming, it is gapped between winding steel wire and the axial steel wire, be hollow pipy metal framework 5. The conductive sealing ring 1 is welded on the end wall of the inner layer pipe 2, the end walls of the middle layer pipe 3 and the outer layer pipe 4 are both welded on the end wall of the conductive sealing ring 1, and the conductive sealing ring 1 is coaxial with the inner layer pipe 2.

The conductive sealing ring 1 and the inner tube 2 of the present embodiment are both made of conductive flame-retardant master batch, the intermediate tube 3 is made of intermediate master batch, and the outer tube 4 is made of outer master batch.

The embodiment provides a conductive flame-retardant master batch, which comprises the following raw materials by weight: 15kg of conductive carbon black, 3kg of bis (trifluoromethane) sulfimide, 4kg of magnesium hydroxide and 78kg of DJ200A type cross-linked polyethylene.

The preparation steps of the conductive flame-retardant master batch are as follows: adding conductive carbon black, bis (trifluoromethanesulfonyl) imide, magnesium hydroxide and DJ200A type cross-linked polyethylene into an extruder, carrying out melt blending, wherein the length-diameter ratio L/D of the extruder is 33, and adjusting the extruder to the following extrusion temperature: a first stage, 200 ℃; a second stage, 205 ℃; a third stage, 215 ℃; a fourth stage, 205 ℃; fifth stage, 205 ℃. And extruding and granulating to obtain the conductive flame-retardant master batch, wherein the surface resistance of the conductive master batch is less than 106 omega, and the flexural modulus is 1030MPa.

The embodiment provides an intermediate layer master batch, which comprises the following raw materials by weight: 79kg of DJ200A type crosslinked polyethylene, 15kg of glass short fiber and 6kg of kh550 type silane coupling agent.

The preparation steps of the intermediate layer master batch are as follows: adding the glass short fibers and the surface treatment agent into a mixer, and uniformly stirring to obtain the modified short fibers. And then adding the modified short fibers and the conductive flame-retardant master batch into an extruder at the same time, carrying out melt blending, wherein the length-diameter ratio L/D of the extruder is 33, and adjusting the extruder to the following extrusion temperature: a first stage, 200 ℃; a second stage, 205 ℃; a third stage, 215 ℃; a fourth stage, 205 ℃; fifth stage, 205 ℃. And extruding and granulating to obtain the intermediate layer master batch.

The embodiment provides an outer layer masterbatch which comprises the following raw materials in parts by weight: 3kg of carbon nano tubes and 97kg of DJ200A type cross-linked polyethylene.

The preparation steps of the outer layer master batch are as follows: adding the carbon nano tube into 150kg of water, performing ultrasonic dispersion, and uniformly dispersing to obtain a dispersion liquid. Then adding DJ200A type cross-linked polyethylene into a grinder, grinding into powder of 800-2000 meshes, adding the powder into the dispersion liquid, continuing to perform ultrasonic dispersion, evaporating to remove water after uniform dispersion, and drying to obtain powder of the outer layer tube 4.

Adding the powder of the outer layer pipe 4 into an extruder for melting, wherein the length-diameter ratio L/D of the extruder is 33, and adjusting the extruder to the following extrusion temperature: a first stage, 200 ℃; a second stage, 205 ℃; a third stage, 215 ℃; a fourth stage, 205 ℃; fifth stage, 205 ℃. And extruding and granulating to obtain the outer layer master batch.

The embodiment provides a preparation method of a conductive sealing ring 1, which comprises the following steps: adding the conductive flame-retardant master batch into an extruder, carrying out melting, wherein the length-diameter ratio L/D of the extruder is 33, and adjusting the extruder to the following extrusion temperature: a first stage, 200 ℃; a second stage, 205 ℃; a third stage, 215 ℃; a fourth stage, 205 ℃; fifth stage, 205 ℃. Extruding the melted materials into a mould, and adjusting the mould core of the mould to the following temperature: a connecting section 205 ℃; a first stage, 205 ℃; a second stage, 200 ℃; a third stage, 200 ℃; and in the fourth stage, extruding the mixture into a pipe at 200 ℃.

And cutting the pipe into rings to obtain the conductive sealing ring 1.

The embodiment provides a preparation method of a composite metal framework pipe, which comprises the following steps:

adding the conductive flame-retardant master batch into an extruder for melting, wherein the length-diameter ratio L/D of the extruder is 33, and adjusting the extruder to the following extrusion temperature: a first stage, 200 ℃; a second stage, 205 ℃; a third stage, 215 ℃; a fourth stage, 205 ℃; fifth stage, 205 ℃. Inserting the metal framework 5 into a mould, extruding the molten material into the mould, and adjusting the mould core of the mould to the following temperature: a connecting section 205 ℃; a first stage, 205 ℃; a second stage, 200 ℃; a third stage, 200 ℃; and in the fourth stage, co-extruding the materials into a pipe material at 200 ℃ to form the inner layer pipe 2.

Then, the inner layer tube 2 was heated, the intermediate layer master batch was fed into an extruder, and melted, the length-to-diameter ratio L/D of the extruder was 33, and the extruder was adjusted to the following extrusion temperatures: a first stage, 200 ℃; a second stage, 205 ℃; a third stage, 215 ℃; a fourth stage, 205 ℃; fifth stage, 205 ℃. The molten material was extruded onto the outer peripheral wall of the inner tube 2, and then co-extruded, that is, the intermediate tube 3 was formed on the outer peripheral wall of the inner tube 2, and the yield strength of the intermediate tube 3 was 28MPa.

Heating the middle layer pipe 3, adding the outer layer master batch into an extruder, melting, wherein the length-diameter ratio L/D of the extruder is 33, and adjusting the extruder to the following extrusion temperature: a first stage, 200 ℃; a second stage, 205 ℃; a third stage, 215 ℃; a fourth stage, 205 ℃; fifth stage, 205 ℃. The molten material is extruded onto the outer peripheral wall of the intermediate layer tube 3, and then co-extrusion is performed, that is, the outer layer tube 4 is formed on the outer peripheral wall of the intermediate layer tube 3.

Then the conductive sealing ring 1 and the inner layer tube 2 are coaxially arranged, and the sum of the wall thickness of the inner layer tube 2, the wall thickness of the middle layer tube 3 and the wall thickness of the outer layer tube 4 is equal to the wall thickness of the conductive sealing ring 1. And then the end wall of the conductive sealing ring 1 is welded with the end walls of the inner layer pipe 2, the middle layer pipe 3 and the outer layer pipe 4 to obtain the composite metal framework pipe.

Example 2

The embodiment provides a composite metal framework pipe, and the difference between the embodiment and the embodiment 1 is that the raw material ratio of the conductive flame-retardant master batch is as follows: 5kg of conductive carbon black, 2kg of bis (trifluoromethanesulfonyl) imide, 3kg of magnesium hydroxide and 90kg of DJ200A type cross-linked polyethylene, wherein the flexural modulus of the conductive flame-retardant master batch is 700MPa.

Example 3

The embodiment provides a composite metal framework pipe, and the difference between the embodiment and the embodiment 1 is that the raw material ratio of the conductive flame-retardant master batch is as follows: 30kg of conductive carbon black, 5kg of bis (trifluoromethane) sulfimide, 6kg of magnesium hydroxide and 59kg of DJ200A type cross-linked polyethylene, and the flexural modulus of the conductive flame-retardant master batch is 1400MPa.

Example 4

The present embodiment provides a composite metal skeleton tube, and the difference between the present embodiment and embodiment 1 is that the raw material ratio of the intermediate layer master batch is as follows: 62kg of DJ200A type cross-linked polyethylene, 30kg of glass short fiber, 8kg of kh550 type silane coupling agent and 35MPa of yield strength of the intermediate layer pipe 3.

Example 5

The present embodiment provides a composite metal skeleton tube, and the difference between the present embodiment and embodiment 1 is that the raw material ratio of the intermediate layer master batch is as follows: 91kg of DJ200A type cross-linked polyethylene, 5kg of glass short fibers, 4kg of kh550 type silane coupling agent and 22MPa of yield strength of the intermediate layer pipe 3.

Example 6

The embodiment provides a composite metal framework pipe, and the difference between the embodiment and the embodiment 1 is that the raw material ratio of the outer layer master batch is as follows: 0.1kg of carbon nano-tube and 99.9kg of DJ200A type cross-linked polyethylene.

Example 7

The present embodiment provides a composite metal framework tube, and the difference between the present embodiment and embodiment 1 is that the raw material ratio of the outer layer masterbatch is as follows: 10kg of carbon nano-tubes and 90kg of DJ200A type cross-linked polyethylene.

Example 8

This example provides a composite metal skeleton tube, and differs from example 1 in that the conductive carbon black is replaced with the same amount of carboxylated carbon nanotubes.

Example 9

This example provides a composite metal skeleton tube, which differs from example 1 in that the conductive carbon black is replaced with an equal amount of multi-walled carbon nanotubes.

Example 10

This example provides a composite metal skeleton tube, which differs from example 1 in that the conductive carbon black is replaced with an equal amount of carbon fiber.

Example 11

This example provides a composite metal skeleton tube, and differs from example 1 in that the bistrifluoromethanesulfonimide is replaced with an equal amount of zinc oxide whiskers.

Example 12

This comparative example, which is different from example 1 in that the intermediate layer master batch was replaced with the same amount of the conductive flame retardant master batch in the production step of the composite metal skeleton tube, provides a composite metal skeleton tube.

Example 13

This comparative example, which differs from example 1 in that the outer layer masterbatch was replaced with the same amount of conductive flame retardant masterbatch in the production step of the composite metal skeleton tube, provides a composite metal skeleton tube.

Comparative example

Comparative example 1

This comparative example, which differs from example 1 in that the composite metal skeleton tube does not contain the conductive seal ring 1, provides a composite metal skeleton tube.

Comparative example 2

This comparative example, which differs from example 1 in that the composite metal skeleton tube does not contain the intermediate layer tube 3, provides a composite metal skeleton tube.

Comparative example 3

This comparative example provides a composite metal skeleton tube which differs from example 1 in that the composite metal skeleton tube does not contain the outer tube 4.

Comparative example 4

The present comparative example, which is different from example 1 in that,

when the composite metal framework pipe is prepared, the conductive flame-retardant master batch is replaced by the same amount of DJ200A type cross-linked polyethylene.

Performance test

The following performance tests were performed on the composite metal skeleton pipes provided in examples 1 to 13 and comparative examples 1 to 4.

The ring stiffness of the sample is detected according to the provisions in GB/T9647, and the flame retardant and antistatic properties of the sample are measured according to the provisions of AQ1071-2009 safety technical requirements for nonmetal gas conveying pipes for coal mines.

The results are shown in Table 1.

TABLE 1

As can be seen by combining example 1 and comparative examples 1 to 3 with Table 1, the ring stiffness was significantly reduced in comparative example 2, comparative example 3 and comparative example 4, and the surface resistance was greater than 10 in comparative examples 1 to 4, compared to example 1⁶Ω, flame retardancy of comparative example 4, etc. were poor. This shows that, under the raw material ratio and the process conditions of example 1 of the present application, it is helpful to simultaneously improve the ring stiffness of the pipe, reduce the surface resistance of the pipe, and improve the flame retardant property of the pipe.

As can be seen by combining examples 1-13 with Table 1, examples 1-13 all have a surface resistance of less than 10⁶Omega, and the ring stiffness is relatively large, and the flame retardant property is relatively good, which shows that under the process conditions of the embodiments 1-13, the method is favorable for preparing the pipe with relatively high ring stiffness, easy molding, and relatively good conductive performance, antistatic performance and flame retardant property.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. A composite metal skeleton tube, characterized in that: including electrically conductive seal ring (1) and from the inside and inlayer pipe (2), intermediate layer pipe (3) and outer pipe (4) that set gradually outward, the inside of inlayer pipe (2) is equipped with metal framework (5), the end wall of inlayer pipe (2), intermediate layer pipe (3) and outer pipe (4) all with electrically conductive end wall fixed connection who seals ring (1).

2. A composite metal skeleton tube according to claim 1, wherein: the conductive sealing ring (1), the inner layer pipe (2), the middle layer pipe (3) and the outer layer pipe (4) all comprise high-elasticity-modulus plastics, and the high-elasticity-modulus plastics are polyethylene or polypropylene.

3. A composite metal skeleton tube according to claim 2, wherein: at least one of the conductive sealing ring (1), the inner layer tube (2), the middle layer tube (3) and the outer layer tube (4) further comprises fibers.

4. A composite metal skeleton tube according to claim 1, wherein: the inner layer pipe (2) and the conductive sealing ring (1) are both layers made of conductive flame-retardant master batch, and the conductive flame-retardant master batch comprises the following raw materials in percentage by weight: 5-30% of conductive filler, 2-5% of antistatic agent, 3-6% of flame retardant and 59-90% of high-elasticity modulus plastic, wherein the surface resistance of the conductive flame-retardant master batch is less than 106 omega, the bending modulus is 700-1400MPa, and the conductive filler is at least one of conductive carbon black, carboxylated carbon nanotubes, multi-walled carbon nanotubes and carbon fibers.

5. The composite metal skeleton tube of claim 4, wherein: the antistatic agent is at least one of an organic antistatic agent and zinc oxide whiskers.

6. The composite metal skeleton tube according to claim 1, wherein the outer layer tube (4) is made of an outer layer master batch, and the outer layer master batch comprises the following raw materials in parts by weight: 0.1-10% of carbon nano tube and 90.0-99.9% of high elastic modulus plastic, wherein the outer layer master batch is prepared by the following steps: dispersing carbon nano tubes in water to obtain a dispersion liquid, crushing high-elasticity modulus plastic into powder, adding the powder into the dispersion liquid, uniformly dispersing, evaporating to remove water, and drying to obtain powder of an outer tube (4); and melting the powder of the outer layer pipe (4), and then extruding and granulating to obtain an outer layer master batch.

7. A composite metal skeleton tube according to claim 1, wherein: the middle layer pipe (3) is made of a middle layer master batch, and the middle layer master batch comprises the following raw materials in percentage by weight: 62 to 91 percent of high elastic modulus plastic, 5 to 30 percent of reinforced short fiber and 4 to 8 percent of surface treating agent; the intermediate layer master batch is prepared by the following steps: uniformly mixing the reinforced short fiber and the surface treating agent to obtain modified short fiber; and (3) melting and blending the modified short fibers and the conductive flame-retardant master batch, and then extruding and granulating to obtain the intermediate layer master batch, wherein the yield strength of the intermediate layer pipe (3) is 22-35MPa.

8. An electrically conductive sealing ring as claimed in any one of claims 1 to 7, wherein: the preparation method comprises the following steps:

extruding or injection molding the conductive flame-retardant master batch to form an annular material, wherein the temperature of the extrusion or injection molding is 200-220 ℃, and the wall thickness of the annular material is greater than or equal to the sum of the wall thicknesses of the inner layer pipe (2), the middle layer pipe (3) and the outer layer pipe (4);

when the conductive flame-retardant master batch is continuously extruded, the annular material is cut in sections to obtain the conductive sealing ring (1);

when the conductive flame-retardant master batch is injected into an annular material, the conductive sealing ring (1) is directly obtained.

9. A process for forming a composite metal skeleton tube according to any one of claims 1 to 7, comprising the steps of:

s1, melting the conductive flame-retardant master batch, extruding the melted conductive flame-retardant master batch onto the outer surface and the inner surface of a metal framework (5), and co-extruding the melted conductive flame-retardant master batch into a pipe to obtain an inner layer pipe (2);

s2, heating the inner layer pipe (2), melting the intermediate layer master batch, extruding the molten intermediate layer master batch onto the outer surface of the inner layer pipe (2), and co-extruding the molten intermediate layer master batch into a pipe material to form an intermediate layer pipe (3);

s3, heating the intermediate layer pipe (3), melting the outer layer master batch, extruding the outer layer master batch onto the outer peripheral wall of the intermediate layer pipe (3), and co-extruding the outer layer master batch into a pipe material to form an outer layer pipe (4);

and S4, welding the conductive sealing ring (1) on the end wall of the outer layer pipe (4), and simultaneously welding the end walls of the inner layer pipe (2) and the middle layer pipe (3) with the conductive sealing ring (1) to obtain the composite metal framework pipe.

10. A process of manufacturing a composite metal skeleton tube according to claim 9, wherein: the extrusion temperatures in S1, S2, S3 and S4 are as follows: a first stage at 190-210 ℃; a second stage, 200-210 ℃; a third stage, 210-220 ℃; the fourth stage, 200-210 ℃; fifth stage, 200-210 deg.C.