Antistatic fluoroplastic compound pipeline lining designed by novel winding method

Abstract

The invention belongs to the field of fluoroplastic pipe preparation, and particularly relates to an antistatic fluoroplastic compound pipeline lining designed by a novel winding method, which comprises a polytetrafluoroethylene electrostatic dredging inner layer, a polytetrafluoroethylene interlayer and a polytetrafluoroethylene electrostatic dredging outer layer from inside to outside in sequence, wherein the polytetrafluoroethylene electrostatic dredging inner layer and the polytetrafluoroethylene electrostatic dredging outer layer can be conductively connected through a conductive bond formed by a conductive polytetrafluoroethylene film strip which is continuously wound at the two ends of the pipeline lining. The invention has the following beneficial effects: electrostatic charges generated in the pipeline can be conducted to the polytetrafluoroethylene electrostatic dredging outer layer through the polytetrafluoroethylene electrostatic dredging inner layer and the conductive bond in conductive connection with the two ends of the pipeline lining; and then the electrostatic charges are conducted to a metal pipeline matched with the antistatic fluoroplastic compound pipeline lining for use, so that the electrostatic charges in the pipeline are released, and a new idea is provided for the antistatic technology of the fluoroplastic pipeline lining.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of fluoroplastic pipes, and particularly relates to an antistatic fluoroplastic composite pipe lining designed by a novel winding method. Background Art

[0002] Fluoroplastic products have excellent mechanical properties and outstanding insulation properties, and are often used as insulation materials. In particular, they have been widely used as linings for pipelines and components in petrochemical industry, natural gas transportation, etc. However, their high resistivity will bring many problems. For example, the static charges generated inside are difficult to dissipate, resulting in a large accumulation of static charges, causing electrostatic discharge and unpredictable consequences, and it is also easy to cause problems such as production safety and product quality. In order to reduce the safety accidents caused by static electricity, it is necessary to improve the antistatic performance of fluoroplastic pipe linings. Currently, a common antistatic method for fluoroplastic pipe linings is segmented conduction. For example, a patent (CN202322776085.X) of Hebei Hongxin Plastic Industry Co., Ltd. proposes to use multiple metal rings to conduct out the static charges in the plastic pipe at equal intervals. However, the static charge conduction efficiency of this method is low, the loss of the pipe is large, and due to the presence of metal conductive substances, its corrosion resistance will also decrease; another method is to replace all traditional fluoroplastic pipe linings with antistatic fluoroplastic pipe linings. For example, in a patent (CN202410459233.1) for preparing antistatic plastics proposed by Jiangxi Suxin New Materials Co., Ltd., modified graphene is used as a conductive agent and mixed into the plastic. Although this method is simple to operate and can effectively conduct out the static charges inside the pipe, due to the excessive amount of graphene used, the cost will increase significantly, resulting in a decline in economic benefits. Obviously, the current antistatic technologies for fluoroplastic pipe linings are not satisfactory, and there is an urgent need to research and invent an efficient and low-cost antistatic technology for fluoroplastic pipe linings. The present invention proposes an antistatic fluoroplastic composite pipe lining designed by a novel winding method, which can not only effectively conduct out the internal static charges of the pipe lining, but also greatly reduce the preparation cost. Summary of the Invention

[0003] The purpose of the present invention is to provide an antistatic fluoroplastic composite pipe lining designed by a novel winding method to overcome the shortcomings and deficiencies of the existing antistatic technologies for fluoroplastic pipe linings.

[0004] The present invention provides an antistatic fluoroplastic composite pipe lining designed by a novel winding method. The antistatic fluoroplastic composite pipe lining includes, from the inside to the outside, a polytetrafluoroethylene static electricity conduction inner layer, a polytetrafluoroethylene interlayer, and a polytetrafluoroethylene static electricity conduction outer layer. The polytetrafluoroethylene static electricity conduction inner layer and the polytetrafluoroethylene static electricity conduction outer layer are both made by respectively winding conductive polytetrafluoroethylene (conductive PTFE) thin film tapes, and the polytetrafluoroethylene interlayer is made by winding polytetrafluoroethylene (PTFE) thin film tapes; the polytetrafluoroethylene static electricity conduction inner layer and the polytetrafluoroethylene static electricity conduction outer layer can be conductively connected through a conductive bond formed by continuously winding conductive polytetrafluoroethylene thin film tapes at both ends of the pipe lining.

[0005] As a further improvement of the present invention, the conductive polytetrafluoroethylene thin film tape is prepared by adding a certain proportion (5wt% - 40wt%) of conductive agents (such as graphene, carbon nanotubes, conductive carbon black, etc.) to the raw material polytetrafluoroethylene powder, uniformly mixing and modifying, and then through processes such as pressing, high-temperature sintering, and turning into sheets. Compared with the unmodified polytetrafluoroethylene thin film tape, it shows excellent conductive performance and can quickly and effectively conduct the static charges generated inside the pipe.

[0006] As a further improvement of the present invention, the polytetrafluoroethylene static electricity conduction inner layer is made by winding the conductive polytetrafluoroethylene thin film tape counterclockwise in sequence and without gaps from the leftmost side to the rightmost side of the mold pipe of the selected specification and model, forming the first layer of conductive polytetrafluoroethylene thin film tightly attached to the mold pipe; according to actual needs, the conductive polytetrafluoroethylene thin film tape can be continued to wind from the rightmost side of the mold pipe back to the leftmost side in sequence and without gaps to form the second layer of conductive polytetrafluoroethylene thin film, and so on to form the required n (n≥1) layers of conductive polytetrafluoroethylene thin films, and finally obtain the wound and formed polytetrafluoroethylene static electricity conduction inner layer; at the same time, the conductive polytetrafluoroethylene thin film tape of the last winding layer is retained on the rightmost side (n is an odd number layer) or the leftmost side (n is an even number layer) of the mold pipe for the subsequent winding preparation of the polytetrafluoroethylene static electricity conduction outer layer and the construction of the conductive bond between the polytetrafluoroethylene static electricity conduction inner layer and the polytetrafluoroethylene static electricity conduction outer layer.

[0007] As a further improvement of the present invention, the polytetrafluoroethylene sandwich layer is formed by winding a polytetrafluoroethylene film tape on the above-mentioned wound polytetrafluoroethylene static electricity conducting inner layer in a counterclockwise direction from the leftmost side of the polytetrafluoroethylene static electricity conducting inner layer in an orderly and gapless manner until the rightmost side, forming the first layer of polytetrafluoroethylene film closely attached to the polytetrafluoroethylene static electricity conducting inner layer; according to actual needs, the polytetrafluoroethylene film tape can be wound from the rightmost side of the polytetrafluoroethylene static electricity conducting inner layer in the reverse direction and then in an orderly and gapless manner until the leftmost side to form the second layer of polytetrafluoroethylene film, and so on in cycles to form the required m (m≥1) layers of polytetrafluoroethylene film, and finally the wound polytetrafluoroethylene sandwich layer is prepared.

[0008] As a further improvement of the present invention, the polytetrafluoroethylene static electricity conducting outer layer is formed by winding the conductive polytetrafluoroethylene film tape remaining on the rightmost side (n is an odd number of layers) or the leftmost side (n is an even number of layers) of the last layer of the polytetrafluoroethylene static electricity conducting inner layer on the mold tube in a reverse direction from the rightmost side (n is an odd number of layers) or the leftmost side (n is an even number of layers) in an orderly and gapless manner to the other side, forming the first layer of conductive polytetrafluoroethylene film closely attached to the polytetrafluoroethylene sandwich layer; according to actual needs, the conductive polytetrafluoroethylene film tape is wound from the polytetrafluoroethylene sandwich layer in the reverse direction and then in an orderly and gapless manner to the other side to form the second layer of conductive polytetrafluoroethylene film, and so on in cycles to form the required N (N≥1) layers of conductive polytetrafluoroethylene film, and finally the wound polytetrafluoroethylene static electricity conducting outer layer is prepared.

[0009] After the above-mentioned winding and forming of the polytetrafluoroethylene static electricity conducting inner layer, the polytetrafluoroethylene sandwich layer and the polytetrafluoroethylene static electricity conducting outer layer are successively completed on the mold tube, a prefabricated part of the antistatic fluoroplastic composite pipe lining with a certain thickness can be prepared; then the prefabricated part is placed at a certain calcination temperature (350 - 450 °C) in an air atmosphere for a period of time (5 - 12 hours) according to different lining thicknesses, and after cooling, it can be formed into an antistatic fluoroplastic composite pipe lining with a certain specification model and thickness through mechanical demolding treatment.

[0010] Finally, the above-prepared antistatic fluoroplastic composite pipe lining is embedded in a metal pipe (such as: stainless steel pipe, carbon steel pipe, alloy pipe, etc.) that matches the specification model of the antistatic fluoroplastic composite pipe lining, and through inlaid roller mechanical rolling, seamless fitting of the antistatic fluoroplastic composite pipe lining and the metal pipe is achieved; finally, both ends of the lining are flanged to fit the interface of the metal pipe port, and then it can be put into actual production for use.

[0011] The beneficial effects of the present invention are as follows: The antistatic fluoroplastic composite pipe liner of the present invention is made by winding a conductive polytetrafluoroethylene film tape and a polytetrafluoroethylene film tape. The static charges generated inside the pipe can be conducted through the polytetrafluoroethylene static charge conduction inner layer and the conductive bond that maintains conductive connection at both ends of the pipe liner to the polytetrafluoroethylene static charge conduction outer layer, and then the static charges are conducted to the metal pipe (such as: stainless steel pipe, carbon steel pipe, alloy pipe, etc.) that is used in matching with the antistatic fluoroplastic composite pipe liner, so as to realize the release of the static charges inside the pipe. It can be seen that the antistatic fluoroplastic composite pipe liner designed by a novel winding method provided by the present invention has obvious antistatic effect, simple preparation process and low cost compared with other antistatic technologies of fluoroplastic pipe liners. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, obtaining other drawings without creative efforts still belongs to the scope of the present invention.

[0013] Figure 1 It is a schematic structural diagram of an antistatic fluoroplastic composite pipe liner designed by a novel winding method: (a) is a schematic structural diagram of the antistatic fluoroplastic composite pipe liner; (b) is a partial enlarged schematic diagram of the cross-section of the antistatic fluoroplastic composite pipe liner.

[0014] Figure 2 It is a schematic diagram of the preparation process of an antistatic fluoroplastic composite pipe liner designed by a novel winding method of the present invention: (a) is a schematic diagram of the preparation process of the polytetrafluoroethylene static charge conduction inner layer; (b) is a schematic diagram of the preparation process of the polytetrafluoroethylene interlayer; (c) and (d) are schematic diagrams of the preparation process of the polytetrafluoroethylene static charge conduction outer layer.

[0015] In the figure, 1 - antistatic fluoroplastic composite pipe liner; 2 - polytetrafluoroethylene static charge conduction inner layer; 3 - polytetrafluoroethylene interlayer; 4 - polytetrafluoroethylene static charge conduction outer layer; 5 - conductive polytetrafluoroethylene film tape; 6 - polytetrafluoroethylene film tape; 7 - conductive bond; 8 - die pipe; 9 - metal pipe DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] To make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings. The directional and positional terms mentioned in the present invention, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "top", "bottom", "side", etc., are only the directions or positions with reference to the accompanying drawings. Therefore, the directional and positional terms used are for explaining and understanding the present invention, rather than limiting the protection scope of the present invention.

[0017] As Figure 1 , an antistatic fluoroplastic composite pipe liner 1 designed by a new winding method, includes a polytetrafluoroethylene electrostatic conduction inner layer 2, a polytetrafluoroethylene interlayer 3, and a polytetrafluoroethylene electrostatic conduction outer layer 4 from inside to outside in sequence. Among them, both the polytetrafluoroethylene electrostatic conduction inner layer 2 and the polytetrafluoroethylene electrostatic conduction outer layer 4 are made by respectively winding conductive polytetrafluoroethylene (conductive PTFE) film tapes 5, and the polytetrafluoroethylene interlayer 3 is made by winding polytetrafluoroethylene (PTFE) film tapes 6. The polytetrafluoroethylene electrostatic conduction inner layer 2 and the polytetrafluoroethylene electrostatic conduction outer layer 4 can be conductively connected through a conductive bond 7 formed by the conductive polytetrafluoroethylene film tapes 5 that are continuously wound at both ends of the pipe liner.

[0018] As a further improvement of the present invention, the conductive polytetrafluoroethylene film tape 5 is prepared by adding a certain proportion (5wt% - 40wt%) of conductive agents (such as graphene, carbon nanotubes, conductive carbon black, etc.) to the raw material polytetrafluoroethylene powder, uniformly mixing and modifying, and then through processes such as pressing, high-temperature sintering, and turning into sheets. Compared with the unmodified polytetrafluoroethylene film tape 6, it shows excellent conductive performance and can quickly and effectively conduct the static charges generated inside the pipe.

[0019] As Figure 2 (a), the polytetrafluoroethylene electrostatic conduction inner layer 2 is made by winding the conductive polytetrafluoroethylene film tape 5 counterclockwise from the leftmost side of the mold tube 8 of the selected specification and model to the rightmost side in an orderly and gapless manner on the mold tube 8, forming the first layer of conductive polytetrafluoroethylene film that closely adheres to the mold tube 8. According to actual needs, the conductive polytetrafluoroethylene film tape 5 can be continued to be wound from the rightmost side of the mold tube 8 back to the leftmost side in an orderly and gapless manner to form the second layer of conductive polytetrafluoroethylene film. In this way, the required n (n≥1) layers of conductive polytetrafluoroethylene film can be formed, and finally the wound polytetrafluoroethylene electrostatic conduction inner layer 2 is prepared. At the same time, the conductive polytetrafluoroethylene film tape 5 of the last winding layer is retained on the rightmost side (n is an odd number layer) or the leftmost side (n is an even number layer) of the mold tube 8 for the subsequent winding preparation of the polytetrafluoroethylene electrostatic conduction outer layer 4 and the construction of the conductive bond between the polytetrafluoroethylene electrostatic conduction inner layer and the polytetrafluoroethylene electrostatic conduction outer layer.

[0020] As Figure 2 (b), the polytetrafluoroethylene sandwich layer 3 is formed by winding a polytetrafluoroethylene film strip 6 on the above-mentioned wound polytetrafluoroethylene static electricity conducting inner layer 2 in a counterclockwise direction from the leftmost side to the rightmost side of the polytetrafluoroethylene static electricity conducting inner layer 2 in an orderly and gapless manner, forming the first layer of polytetrafluoroethylene film that adheres tightly to the polytetrafluoroethylene static electricity conducting inner layer 2; according to actual requirements, the polytetrafluoroethylene film strip 6 can be wound from the rightmost side of the polytetrafluoroethylene static electricity conducting inner layer 2 in the reverse direction and then in an orderly and gapless manner to the leftmost side to form the second layer of polytetrafluoroethylene film. In this way, m (m≥1) layers of polytetrafluoroethylene film can be formed by cycling, and finally the wound polytetrafluoroethylene sandwich layer 3 is obtained by preparation.

[0021] The polytetrafluoroethylene static electricity conducting outer layer 4 is formed by the conductive polytetrafluoroethylene film strip 5 (as shown in Figure 2 (c)) remaining on the rightmost side (n is an odd number layer) or the leftmost side (n is an even number layer) of the last layer of the polytetrafluoroethylene static electricity conducting inner layer 2 of the mold tube 8 and winding it in an orderly and gapless manner in the reverse direction from the rightmost side (n is an odd number layer) or the leftmost side (n is an even number layer) on the polytetrafluoroethylene sandwich layer 3 to the other side, forming the first layer of conductive polytetrafluoroethylene film that adheres tightly to the polytetrafluoroethylene sandwich layer 3, as shown in Figure 2 (d); according to actual requirements, the conductive polytetrafluoroethylene film strip 5 is wound from the polytetrafluoroethylene sandwich layer 3 in the reverse direction and then in an orderly and gapless manner to the other side to form the second layer of conductive polytetrafluoroethylene film. In this way, N (N≥1) layers of conductive polytetrafluoroethylene film can be formed by cycling, and finally the wound polytetrafluoroethylene static electricity conducting outer layer 4 is obtained by preparation.

[0022] After the above-mentioned winding and forming of the polytetrafluoroethylene static electricity conducting inner layer 2, the polytetrafluoroethylene sandwich layer 3, and the polytetrafluoroethylene static electricity conducting outer layer 4 are successively completed on the mold tube 8, a prefabricated part of the antistatic fluoroplastic composite pipe lining with a certain thickness can be obtained by preparation; then, the prefabricated part is placed at a certain calcination temperature (350 - 450 °C) in an air atmosphere for a certain period of time (5 - 12 hours) according to different lining thicknesses, and after cooling, it can form the antistatic fluoroplastic composite pipe lining 1 with a certain specification model and thickness through mechanical demolding treatment.

[0023] Finally, the above-prepared antistatic fluoroplastic composite pipe lining 1 is embedded into a metal pipe 9 (such as: stainless steel pipe, carbon steel pipe, alloy pipe, etc.) that matches the specification model of the antistatic fluoroplastic composite pipe lining 1, and through inlaid roller mechanical rolling, the seamless fitting of the antistatic fluoroplastic composite pipe lining 1 and the metal pipe 8 is realized; finally, both ends of the lining are flanged to fit the interface of the metal pipe 8 port, and then it can be put into actual production for use.

[0024] The antistatic fluoroplastic composite pipe liner 1 designed by a new winding method provided by the present invention, the static charges generated inside it can be conducted through the polytetrafluoroethylene static electricity conduction inner layer 2 and the conductive bond 7 that maintains conductive connection at both ends of the pipe liner to the polytetrafluoroethylene static electricity conduction outer layer 4, and then conduct the static charges to the metal pipe 9 (such as: stainless steel pipe, carbon steel pipe, alloy pipe, etc.) used in matching with the antistatic fluoroplastic composite pipe liner 1, so as to realize the release of the static charges inside the pipe.

[0025] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. An antistatic fluoroplastic composite pipe lining designed by a novel winding method, the antistatic fluoroplastic composite pipe lining comprises, from inside to outside, a polytetrafluoroethylene electrostatic drainage inner layer, a polytetrafluoroethylene interlayer, and a polytetrafluoroethylene electrostatic drainage outer layer, wherein the polytetrafluoroethylene electrostatic drainage inner layer and the polytetrafluoroethylene electrostatic drainage outer layer are both made by winding conductive polytetrafluoroethylene film tapes, respectively, and the polytetrafluoroethylene interlayer is made by winding polytetrafluoroethylene film tapes.

2. The antistatic fluoroplastic composite pipe lining designed by a novel winding method according to claim 1 is characterized in that: The polytetrafluoroethylene electrostatic drainage inner layer and the polytetrafluoroethylene electrostatic drainage outer layer can be electrically connected through a conductive bond consisting of a conductive polytetrafluoroethylene film tape that is continuously wound at both ends of the pipeline lining.

3. The antistatic fluoroplastic composite pipe lining designed by a novel winding method according to claim 1 is characterized in that: The conductive polytetrafluoroethylene film tape is prepared by adding a certain proportion of conductive agent to raw polytetrafluoroethylene powder, uniformly mixing and modifying the raw material, and then subjecting the raw material to pressing, high-temperature sintering, and lathe-cutting processes; the added conductive agent can be graphene, carbon nanotubes, conductive carbon black, etc.; the added amount of the conductive agent is 5wt% to 40wt%.

4. The antistatic fluoroplastic composite pipe lining designed by a novel winding method according to claim 1 is characterized in that: The polytetrafluoroethylene electrostatic drainage inner layer is formed by winding a conductive polytetrafluoroethylene film tape on a mold tube of a selected specification and model from the leftmost side of the mold tube counterclockwise in an orderly and gapless manner to the rightmost side of the mold tube, so as to form a first layer of conductive polytetrafluoroethylene film close to the mold tube; according to actual needs, the conductive polytetrafluoroethylene film tape can be further wound from the rightmost side of the mold tube to the leftmost side in an orderly and gapless manner in the reverse direction to form a second layer of conductive polytetrafluoroethylene film, and such a cycle can form the required n (n≥1) layers of conductive polytetrafluoroethylene film, and finally prepare a wound polytetrafluoroethylene electrostatic drainage inner layer; at the same time, the conductive polytetrafluoroethylene film tape of the last wound layer is retained on the rightmost side (n is an odd number of layers) or the leftmost side (n is an even number of layers) of the mold tube for subsequent winding preparation of the polytetrafluoroethylene electrostatic drainage outer layer and construction of a conductive bond between the polytetrafluoroethylene electrostatic drainage inner layer and the polytetrafluoroethylene electrostatic drainage outer layer.

5. The antistatic fluoroplastic composite pipe lining designed by a novel winding method according to claim 1 is characterized in that: The polytetrafluoroethylene interlayer is formed by winding a polytetrafluoroethylene film tape on a polytetrafluoroethylene electrostatic drainage inner layer, and winding it counterclockwise from the leftmost side of the polytetrafluoroethylene electrostatic drainage inner layer to the rightmost side in an orderly and gapless manner to form a first layer of polytetrafluoroethylene film that is tightly attached to the polytetrafluoroethylene electrostatic drainage inner layer; according to actual needs, the polytetrafluoroethylene film tape can be reversely wound from the rightmost side of the polytetrafluoroethylene electrostatic drainage inner layer to the leftmost side in an orderly and gapless manner to form a second layer of polytetrafluoroethylene film, and such a cycle can form the required m (m≥1) layers of polytetrafluoroethylene film, and finally prepare a wound polytetrafluoroethylene interlayer.

6. The antistatic fluoroplastic composite pipe lining designed by a novel winding method according to claim 1 is characterized in that: The polytetrafluoroethylene electrostatic drainage outer layer is formed by the conductive polytetrafluoroethylene film tape of the last layer of the polytetrafluoroethylene electrostatic drainage inner layer retained on the rightmost (n is an odd-numbered layer) or the leftmost (n is an even-numbered layer) of the mold tube being reversely wound from the rightmost (n is an odd-numbered layer) or the leftmost (n is an even-numbered layer) to the other side in order and without gaps on the polytetrafluoroethylene interlayer to form a first layer of conductive polytetrafluoroethylene film close to the polytetrafluoroethylene interlayer; according to actual needs, the conductive polytetrafluoroethylene film tape is reversely wound from the polytetrafluoroethylene interlayer to the other side in order and without gaps to form a second layer of conductive polytetrafluoroethylene film, and the required N (N≥1) layers of conductive polytetrafluoroethylene film can be formed by such a cycle, and finally a wound polytetrafluoroethylene electrostatic drainage outer layer is prepared.

7. The antistatic fluoroplastic composite pipe lining designed by a novel winding method according to claim 1 is characterized in that: After the polytetrafluoroethylene electrostatic drainage inner layer, the polytetrafluoroethylene interlayer and the polytetrafluoroethylene electrostatic drainage outer layer are successively wound on the mold tube, an antistatic fluoroplastic composite pipe lining preform of a certain thickness can be prepared; the preform is placed at a certain calcination temperature in an air atmosphere for a period of time according to different lining thicknesses, and after cooling, it is subjected to mechanical demolding treatment to form an antistatic fluoroplastic composite pipe lining with a certain specification and thickness; the calcination temperature is 350-450°C, and the treatment time is 5-12 hours.

8. The antistatic fluoroplastic composite pipe lining designed by a novel winding method according to claim 7 is characterized in that: The antistatic fluoroplastic composite pipe lining is embedded in a metal pipe that matches the specifications and models of the antistatic fluoroplastic composite pipe lining, and is mechanically rolled by an embedded roller to achieve seamless fitting of the antistatic fluoroplastic composite pipe lining and the metal pipe. Finally, both ends of the antistatic fluoroplastic composite pipe lining are flanged to fit the metal pipe port interface. The metal pipe can be a stainless steel pipe, a carbon steel pipe, an alloy pipe, etc.

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