High temperature resistant tetrafluoroethylene pipe

Abstract

This invention discloses a high-temperature resistant PTFE pipe, comprising a pure PTFE inner layer, an intermediate reinforcing layer, and a modified PTFE outer layer, arranged sequentially from the inside to the outside. The high-temperature resistant fiber woven mesh, sintered and embedded into the PTFE matrix of the intermediate reinforcing layer, provides radial compressive strength while maintaining axial flexibility, significantly suppressing axial or radial deformation at high temperatures. The long-term operating temperature can be increased to 300°C. Furthermore, a hot-pressed composite flame-retardant layer on the modified PTFE outer layer acts as a thermal barrier, reducing the conduction of external heat to the PTFE matrix. Stainless steel annular reinforcing ribs are provided at both ends of the inner surface of the PTFE pipe to reinforce stress concentration areas, such as flange connections, without affecting overall flexibility. Metal wires and plates are embedded within the annular reinforcing ribs to disperse thermal stress.

Description

Technical Field

[0001] This utility model relates to the field of polymer materials technology, specifically to a high-temperature resistant tetrafluoroethylene tube. Background Technology

[0002] PTFE tubing is a high-performance industrial plastic tubing made from tetrafluoroethylene monomers. It has excellent corrosion resistance and temperature resistance, making it suitable for conveying highly corrosive gaseous and liquid media, such as nitric acid, sulfuric acid, and hydrofluoric acid. It is known as the "King of Plastics". However, traditional PTFE tubing is prone to creep, deformation, or thermal decomposition under long-term high temperatures (such as above 260°C), which leads to a decrease in sealing performance.

[0003] The prior art, disclosed in patent document CN222316341U, presents the following technical solution: a high-temperature and negative-pressure resistant polytetrafluoroethylene pipe, comprising a pipe body, a concave locking block fixedly connected to the right side of the pipe body, a convex locking block fixedly connected to the left side of the pipe body, a negative-pressure resistant layer fixedly sleeved on the outer surface of the pipe body, a high-temperature resistant layer fixedly sleeved on the outer surface of the negative-pressure resistant layer, and a wear-resistant layer fixedly sleeved on the outer surface of the high-temperature resistant layer. The high-temperature resistant layer comprises a polyimide layer, and the inner surface of the polyimide layer is fixedly connected to the negative-pressure resistant layer.

[0004] The above technical solution achieves high temperature resistance through a multi-layer composite structure of polyimide layer, polyetherketone layer and polyphenylene sulfide layer. However, the polyimide layer, polyetherketone layer and polyphenylene sulfide layer are all rigid materials. After the multiple layers are stacked, the pipe has poor bending performance and is prone to brittle cracking, and it is impossible to balance pressure resistance and flexibility. Utility Model Content

[0005] The purpose of this invention is to provide a high-temperature resistant PTFE tube to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a high-temperature resistant PTFE pipe, comprising a pure PTFE inner layer, an intermediate reinforcing layer, and a modified PTFE outer layer, wherein the pure PTFE inner layer, the intermediate reinforcing layer, and the modified PTFE outer layer are arranged sequentially from the inside to the outside.

[0007] The intermediate reinforcing layer is embedded with a high-temperature resistant fiber woven mesh. Both ends of the inner surface of the pure PTFE inner layer are provided with annular embedding grooves. Annular reinforcing ribs are embedded in the annular embedding grooves. The annular reinforcing ribs are arranged in a circumferential direction with through holes. Metal wires are embedded in the through holes. An arc-shaped cavity is provided between two adjacent through holes. A metal plate is embedded in the arc-shaped cavity.

[0008] In the above technical solution, stainless steel annular reinforcing ribs are set at both ends of the inner surface of the PTFE pipe, which can enhance stress concentration areas, such as flange connections, without affecting the overall flexibility. Furthermore, metal wires and metal plates are embedded in the annular reinforcing ribs to disperse thermal stress.

[0009] As a further preferred embodiment of this technical solution, the high-temperature resistant fiber woven mesh is made of polyimide fiber or ceramic fiber material.

[0010] As a further preferred embodiment of this technical solution, the high-temperature resistant fiber woven mesh includes transverse fibers and longitudinal fibers, which are interwoven to form a mesh.

[0011] In the above technical solution, the high-temperature resistant fiber woven mesh is embedded in the PTFE matrix of the intermediate reinforcing layer by sintering, which can provide radial compressive strength while maintaining axial flexibility, and can significantly suppress axial or radial deformation at high temperatures.

[0012] As a further preferred embodiment of this technical solution, a flame-retardant layer is arranged in the circumferential direction of the modified PTFE outer layer, and the flame-retardant layer is embedded in the modified PTFE outer layer using ceramicized silicone tape.

[0013] In the above technical solution, the modified PTFE outer layer, through hot-pressed composite flame-retardant layer, can act as a thermal barrier to reduce the conduction of external heat to the PTFE matrix.

[0014] As a further preferred embodiment of this technical solution, nano-silica or graphene is added to the outer layer of the modified PTFE to enhance its resistance to ultraviolet radiation and aging.

[0015] As a further preferred embodiment of this technical solution, the modified PTFE outer layer is provided with a wear-resistant layer, which is made by blending PTFE with wear-resistant ceramic particles and firing them.

[0016] In the above technical solution, the wear-resistant layer improves the wear resistance of the PTFE pipe.

[0017] As a further preferred embodiment of this technical solution, the annular reinforcing rib is an annular stainless steel strip, which is molded and embedded in the annular embedding groove.

[0018] This utility model provides a high-temperature resistant PTFE tube, which has the following beneficial effects:

[0019] (1) The high-temperature resistant fiber woven mesh set in this utility model can provide radial compressive strength while maintaining axial flexibility by sintering and embedding it into the PTFE matrix of the intermediate reinforcing layer. It can significantly suppress axial or radial deformation at high temperature and can increase the long-term service temperature to 300°. In addition, the modified PTFE outer layer is filled with a hot-pressed composite flame retardant layer, which can act as a thermal barrier to reduce the conduction of external heat to the PTFE matrix.

[0020] (2) By setting stainless steel annular reinforcing ribs at both ends of the inner surface of the PTFE pipe, the present invention can enhance the stress concentration area, such as the flange connection, without affecting the overall flexibility. Furthermore, metal wires and metal plates are embedded in the annular reinforcing ribs to disperse thermal stress. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0022] Figure 2 This is a partial cross-sectional view of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the high-temperature resistant fiber woven mesh of this utility model;

[0024] Figure 4 This is a partial cross-sectional view of the reinforcing rib of this utility model;

[0025] Figure 5 This is an enlarged view of Figure A of this utility model;

[0026] In the diagram: 1. Pure PTFE inner layer; 11. Annular embedded groove; 12. Annular reinforcing rib; 13. Through hole; 14. Arc-shaped cavity; 15. Metal wire; 16. Metal plate; 2. Intermediate reinforcing layer; 3. High-temperature resistant fiber woven mesh; 31. Transverse fiber; 32. Longitudinal fiber; 4. Modified PTFE outer layer; 5. Flame retardant layer; 6. Wear-resistant layer. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0028] This utility model provides a technical solution: such as Figure 1 As shown in this embodiment, a high-temperature resistant PTFE pipe includes a pure PTFE inner layer 1, an intermediate reinforcing layer 2, and a modified PTFE outer layer 4. The pure PTFE inner layer 1, the intermediate reinforcing layer 2, and the modified PTFE outer layer 4 are arranged sequentially from the inside to the outside. The purity of the pure PTFE inner layer 1 is ≥99.6%, ensuring chemical inertness and lubricity.

[0029] like Figure 2 and Figure 3As shown, a high-temperature resistant fiber woven mesh 3 is embedded inside the intermediate reinforcing layer 2. The high-temperature resistant fiber woven mesh 3 is made of polyimide fiber or ceramic fiber material. The high-temperature resistant fiber woven mesh 3 includes transverse fibers 31 and longitudinal fibers 32. The transverse fibers 31 and longitudinal fibers 32 are interwoven to form a mesh. The high-temperature resistant fiber woven mesh 3 is embedded in the PTFE matrix of the intermediate reinforcing layer 2 by sintering. It can provide radial compressive strength while maintaining axial flexibility. It can significantly suppress axial or radial deformation at high temperatures and can increase the long-term service temperature to 300°.

[0030] like Figure 4 and Figure 5 As shown, both ends of the inner surface of the pure PTFE inner layer 1 are provided with annular embedded grooves 11, and annular reinforcing ribs 12 are embedded in the annular embedded grooves 11. The annular reinforcing ribs 12 are annular stainless steel strips, which are embedded in the annular embedded grooves 11 by molding. The annular reinforcing ribs 12 are provided with through holes 13 arranged in the circumferential direction. Metal wires 15 are embedded in the through holes 13. An arc-shaped cavity 14 is provided between two adjacent through holes 13. Metal plates 16 are embedded in the arc-shaped cavity 14. By setting stainless steel annular reinforcing ribs 12 at both ends of the inner surface of the PTFE pipe, stress concentration areas, such as flange connections, can be enhanced without affecting the overall flexibility. In addition, the metal wires 15 and metal plates 16 embedded in the annular reinforcing ribs 12 can disperse thermal stress.

[0031] like Figure 1 and Figure 5 As shown, flame retardant layers 5 are arranged in a circular direction on the modified PTFE outer layer 4. The flame retardant layers 5 are embedded in the modified PTFE outer layer 4 using ceramicized silicone tape. Nano-silica or graphene is added to the modified PTFE outer layer 4 to improve its UV resistance and anti-aging properties. The modified PTFE outer layer 4 can act as a thermal barrier by hot-pressing the flame retardant layers 5 to reduce the conduction of external heat to the PTFE matrix.

[0032] like Figure 1 As shown, the modified PTFE outer layer 4 is provided with a wear-resistant layer 6. The wear-resistant layer 6 is made by blending and firing PTFE and wear-resistant ceramic particles. The wear-resistant layer 6 improves the wear resistance of the PTFE pipe.

[0033] This utility model provides a high-temperature resistant PTFE pipe. The specific working principle is as follows: the high-temperature resistant fiber braided mesh 3 is sintered and embedded in the PTFE matrix of the intermediate reinforcing layer 2, which can provide radial compressive strength while maintaining axial flexibility. It can significantly suppress axial or radial deformation at high temperatures and can increase the long-term operating temperature to 300°. Annular reinforcing ribs 12 are molded at both ends of the inner surface of the PTFE pipe to enhance stress concentration areas, such as flange connections, without affecting the overall flexibility. Metal wires 15 and metal plates 16 are embedded in the annular reinforcing ribs 12 to disperse thermal stress.

[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-temperature resistant PTFE pipe, comprising a pure PTFE inner layer (1), an intermediate reinforcing layer (2), and a modified PTFE outer layer (4), characterized in that: The pure PTFE inner layer (1), the intermediate reinforcing layer (2), and the modified PTFE outer layer (4) are arranged sequentially from the inside to the outside; The intermediate reinforcing layer (2) is embedded with a high-temperature resistant fiber woven mesh (3). Both ends of the inner surface of the pure PTFE inner layer (1) are provided with annular embedding grooves (11). Annular reinforcing ribs (12) are embedded in the annular embedding grooves (11). Through holes (13) are arranged in the circumferential direction of the annular reinforcing ribs (12). Metal wires (15) are embedded in the through holes (13). An arc-shaped cavity (14) is provided between two adjacent through holes (13). A metal plate (16) is embedded in the arc-shaped cavity (14).

2. The high-temperature resistant PTFE pipe according to claim 1, characterized in that: The high-temperature resistant fiber woven mesh (3) is made of polyimide fiber or ceramic fiber material.

3. The high-temperature resistant PTFE pipe according to claim 1, characterized in that: The high-temperature resistant fiber woven mesh (3) includes transverse fibers (31) and longitudinal fibers (32), which are interwoven to form a mesh.

4. The high-temperature resistant PTFE pipe according to claim 1, characterized in that: The modified PTFE outer layer (4) has a flame-retardant layer (5) arranged in the circumferential direction. The flame-retardant layer (5) is embedded in the modified PTFE outer layer (4) using ceramicized silicone tape.

5. The high-temperature resistant PTFE pipe according to claim 1, characterized in that: The modified PTFE outer layer (4) is supplemented with nano-silica or graphene to enhance its UV resistance and anti-aging properties.

6. The high-temperature resistant PTFE pipe according to claim 1, characterized in that: The modified PTFE outer layer (4) is provided with a wear-resistant layer (6), which is made by blending PTFE and wear-resistant ceramic particles and firing them.

7. The high-temperature resistant PTFE pipe according to claim 1, characterized in that: The annular reinforcing rib (12) is an annular stainless steel strip, which is embedded in the annular embedding groove (11) by molding.

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