Mpp cable protection pipe and adhesive

Abstract

The application relates to the technical field of the manufacturing of MPP cable protection pipes, and relates to an MPP cable protection pipe which comprises an inner pipe and an outer pipe made of MPP; the inner pipe has coiled steel wires in the inside; the steel wires are winding steel wires; the outer pipe comprises a plurality of pipe pieces with arc-shaped cross sections; the plurality of pipe pieces are arranged around the outside of the inner pipe to form the outer pipe; a plurality of steel wires parallel to the length direction of the pipe pieces are arranged in the inside of the pipe pieces; the steel wires are straight steel wires; the inside of the plurality of pipe pieces and the outside of the inner pipe are bonded together by bonding glue; and the bonding glue is first bonding glue. The MPP cable protection pipe has the advantages of higher strength and longer service life; and the application further provides a manufacturing method of the MPP cable protection pipe.

Description

Technical Field

[0001] This invention relates to the field of manufacturing technology of MPP cable protection pipes, and more specifically to MPP cable protection pipes and adhesives. Background Technology

[0002] Patent document CN111363286A, entitled "A Modified MPP Cable Protection Pipe," discloses a modified MPP cable protection pipe comprising the following raw materials by weight: modified acrylic resin, graphene A, carbon black, coupling agent, toughening agent, compatibilizer (3-5 parts), lubricant, antioxidant, nano-calcium carbonate, titanium dioxide, and flame retardant. The resulting MPP cable protection pipe exhibits strong corrosion resistance, low coefficient of friction, heat resistance, and cold resistance. However, its mechanical strength and service life have not yet reached ideal requirements, and it cannot meet some installation requirements.

[0003] For example, in the patent document with publication number "CN114133672A" and title "A High-Strength and High-Pressure-Resistant MPP Cable Protection Pipe", a high-strength and high-pressure-resistant MPP cable protection pipe is disclosed, which includes the following raw materials by weight: 100-150 parts MPP, 25-40 parts pressure-resistant modifier, nano calcium carbonate, plasticizer, stabilizer, compatibilizer, toughening agent, etc.; however, its mechanical strength and service life have not yet reached the ideal requirements and cannot meet some installation requirements. Summary of the Invention

[0004] The purpose of this invention is to address the above-mentioned shortcomings by providing an MPP cable protection pipe with higher strength, less susceptibility to cracking, and longer service life, as well as an adhesive.

[0005] The technical solution of the MPP cable protection pipe of the present invention is implemented as follows: An MPP cable protection pipe includes an inner tube and an outer tube made of MPP. The inner tube has coiled steel wire inside, which is a wound steel wire. The outer tube includes multiple tube segments with an arc-shaped cross-section. The multiple tube segments surround the outer tube to form an outer tube. Inside the tube segments are multiple steel wires parallel to the length direction of the tube segments. These steel wires are straight steel wires. The inner sides of the multiple tube segments and the outer side of the inner tube are bonded together with adhesive. This adhesive is a first adhesive.

[0006] Furthermore, the tube segment has an arc-shaped outer surface, an arc-shaped inner surface, and a radial surface. An adhesive is also applied between the radial surfaces of adjacent tube segments; this adhesive is a second adhesive.

[0007] Furthermore, the radial sides of adjacent segments also have grooves for accommodating reinforcing ribs, and the reinforcing ribs are in these grooves. The reinforcing ribs are bonded to the grooves with adhesive, which is a second adhesive.

[0008] To elaborate further, the reinforcing ribs are steel wires.

[0009] Furthermore, the steel wire also has a roughened layer on the outside.

[0010] Furthermore, there are at least two reinforcing ribs on the sides of adjacent segments. One side of these two reinforcing ribs is connected to the radial side of the two adjacent segments by injection molding. The other side of these two reinforcing ribs is bonded to the radial side of another segment with a second adhesive.

[0011] Furthermore, there are stainless steel retaining rings with openings on the outside of the outer tube, which keep multiple tube segments in a clamped state.

[0012] Furthermore, there is a protective coating on the outside of the outer tube.

[0013] Furthermore, the adhesive is a mixture of materials containing the following parts by weight; 50-60 parts of viscous epoxy resin, 20-25 parts of emulsified polyvinyl acetate, 18-20 parts of viscous dihydroxy polydimethylsiloxane, 15-20 parts of xylene, 12-15 parts of nano carbon powder, 8-10 parts of ethyl α-cyanoacrylate, 8-10 parts of boron nitride powder, 10-15 parts of thermoplastic elastomer, 3-5 parts of flame retardant, and 10-12 parts of coupling agent; Furthermore, the second adhesive is a mixture of materials containing the following parts by weight; 15-20 parts of 2-methyl-4-ethylimidazole, 10-12 parts of xylene, 5-7 parts of epoxy resin, 7-10 parts of dibutyl phthalate, 8-10 parts of vinyl resin, 8-10 parts of methylcellulose, 5-10 parts of stone powder, 5-7 parts of xylene, 5-7 parts of acetone, and 5-7 parts of dibutyl phthalate.

[0014] Furthermore, the protective coating is formed by spraying a mixture of the above-mentioned adhesive and 100-mesh butadiene rubber powder at a mass ratio of 1:1-2.

[0015] Furthermore, the protective coating is formed by spraying a mixture of the aforementioned second adhesive and 100-mesh butadiene rubber powder at a mass ratio of 1:1-2.

[0016] Furthermore, the protective coating is formed by spraying and solidifying the following protective paint: It is a mixture of 10-15 parts polyvinyl alcohol powder, 20-25 parts n-butyl acrylate, 20-22 parts acrylic acid, 10-12 parts methylcellulose, 3-5 parts hydroxyl-terminated polydimethylsiloxane, 7-10 parts sodium sulfate powder, 5-7 parts methylhydroquinone powder, 3-5 parts hydroquinone, 6-8 parts 100-mesh cis-butadiene rubber powder, and 8-10 parts 100-mesh ceramic powder.

[0017] The technical solution of the manufacturing method of the MPP cable protection pipe of the present invention is as follows: A manufacturing method of an MPP cable protection pipe includes an inner tube and an outer tube made of MPP. The inner tube has coiled steel wire inside, which is a wound steel wire. The outer tube includes multiple tube segments with an arc-shaped cross-section. Each tube segment has steel wire parallel to its length direction. These steel wires are straight steel wires. The multiple tube segments are bonded to the outside of the inner tube with an adhesive, which is a first adhesive. The adhesive is a mixture containing the following parts by weight... The mixture comprises: 50-60 parts of viscous epoxy resin, 20-25 parts of emulsified polyvinyl acetate, 18-20 parts of viscous dihydroxypolydimethylsiloxane, 15-20 parts of xylene, 12-15 parts of 200-mesh nano carbon powder, 8-10 parts of ethyl α-cyanoacrylate, 8-10 parts of boron nitride powder, 10-15 parts of thermoplastic elastomer, 3-5 parts of flame retardant, and 10-12 parts of coupling agent mixture; when the adhesive is applied between the inner and outer tubes, the temperature of the inner and outer tubes is 65-75°C, and the temperature of the adhesive is 25-30°C.

[0018] On the outside of the outer tube, an adhesive is applied to the gaps between adjacent tube segments; this adhesive is a second adhesive. The tube segments have an arc-shaped outer surface, an arc-shaped inner surface, and a radial surface. The radial surfaces of adjacent tube segments also have grooves for accommodating reinforcing ribs, and the reinforcing ribs are embedded in these grooves. These reinforcing ribs are bonded to the grooves with adhesive, which is also a second adhesive. The reinforcing ribs are steel wires; the steel wires also have a roughened layer on the outside. The second adhesive contains the following mass... The mixture comprises the following components: 15-20 parts 2-methyl-4-ethylimidazolium, 10-12 parts xylene, 5-7 parts epoxy resin, 7-10 parts dibutyl phthalate, 8-10 parts vinyl resin, 8-10 parts methylcellulose, 5-10 parts stone powder, 5-7 parts xylene, 5-7 parts acetone, and 5-7 parts dibutyl phthalate; when applying the second adhesive to the gap between adjacent segments or to the surface of the reinforcing rib; the temperature of the second adhesive is equal to the temperature of the outer tube.

[0019] Furthermore, there is a protective coating on the outside of the outer tube; the protective coating is formed by spraying and solidifying the following protective paint: 10-15 parts polyvinyl alcohol powder, 20-25 parts n-butyl acrylate, 20-22 parts acrylic acid, 10-12 parts methylcellulose, 3-5 parts hydroxyl-terminated polydimethylsiloxane, 7-10 parts sodium sulfate powder, 5-7 parts methylhydroquinone powder, 3-5 parts hydroquinone, 6-8 parts 100-mesh cis-butadiene rubber powder, and 8-10 parts 100-mesh ceramic powder. When the protective paint is sprayed on the outside of the outer tube, the temperature of the outer tube is 65-75°C, and the temperature of the protective paint is 25-30°C. The ambient temperature is maintained at 55-60°C for 12 hours after spraying, slowly cooling down to 25-30°C.

[0020] The beneficial effects of this invention are that the manufacturing method of such MPP cable protection pipe has the advantages of producing MPP cable protection pipe with higher strength and longer service life. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the MPP cable protection pipe of the present invention.

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure of the MPP cable protection pipe of the present invention.

[0023] Figure 3 This is a schematic diagram of the pipe segments used in the MPP cable protection pipe of the present invention.

[0024] Figure 4 This is a schematic diagram showing the positional relationship between two adjacent tunnel segments.

[0025] Figure 5 yes Figure 4 Enlarged view of part A in the image.

[0026] Among them: 1. Inner tube 11. Winding steel wire 2. Outer tube 21. Tube segment 211. Straight steel wire 212. Outer side 213. Inner side 214. Radial side 2141. Groove 215. Reinforcing rib 3. Adhesive 31. First adhesive 32. Second adhesive 4. Clamping ring 41. Opening 5. Protective coating. Detailed Implementation

[0027] The present invention will be further described below with reference to the embodiments.

[0028] As shown in the figure, an MPP cable protection pipe includes an inner tube 1 and an outer tube 2 made of MPP. The inner tube has coiled steel wires inside, which are wound steel wires 11. The outer tube includes multiple tube segments 21 with arc-shaped cross-sections. The multiple tube segments surround the outer tube to form the outer tube. Inside the tube segments are multiple steel wires parallel to the length direction of the tube segments. These steel wires are straight steel wires 211. The inner sides of the multiple tube segments and the outer side of the inner tube are bonded together with adhesive 3. This adhesive is the first adhesive 31.

[0029] Generally, adhesives have higher strength. The arrangement in this invention, compared to having both ring-shaped and straight steel wires inside an MPP tube, provides significantly higher strength. The ring-shaped and straight steel wires form a mesh structure; the ring-shaped wires are equivalent to the wound steel wires in this invention, and the straight steel wires are equivalent to the straight steel wires. This arrangement also offers advantages such as easier molding, reduced production costs, and suitability for mass production.

[0030] Furthermore, the tube segment has an arc-shaped outer surface 212, an arc-shaped inner surface 213, and a radial surface 214. An adhesive is also applied between the radial surfaces of adjacent tube segments. This adhesive is a second adhesive 32.

[0031] This invention also has the advantage of creating an outer tube with higher strength, which makes the MPP cable protection tube have higher strength because the adhesive material has better strength.

[0032] Furthermore, the radial side of the adjacent segments also has a groove 2141 for accommodating reinforcing ribs, and a reinforcing rib 215 in this groove. The reinforcing rib is bonded to the groove with adhesive 3, which is a second adhesive 32.

[0033] This design also has the advantage of creating an outer tube with higher strength. On the one hand, the presence of reinforcing ribs makes the outer tube stronger. On the other hand, the presence of reinforcing ribs and the unevenness they cause make the adhesive bond more firmly in this area.

[0034] To elaborate further, the reinforcing ribs are steel wires.

[0035] This invention is designed such that, on the one hand, the steel wire has higher load-bearing strength, and on the other hand, the adhesion between the steel wire and the adhesive is stronger, thus increasing the load-bearing strength of this MPP cable protection pipe.

[0036] Furthermore, the steel wire also has a roughened layer on the outside.

[0037] This design also makes the adhesion between the steel wire and the adhesive stronger, thus increasing the strength and service life of the MPP cable protection pipe.

[0038] Furthermore, there are at least two reinforcing ribs on the sides of adjacent segments. One side of these two reinforcing ribs is connected to the radial side of the two adjacent segments by injection molding. The other side of these two reinforcing ribs is bonded to the radial side of another segment with a second adhesive.

[0039] To better understand the above technical solutions, such as Figure 4 , 5 As shown, for example, adjacent segments are a first segment 21A and a second segment 21B. The radial side of the first segment is a first radial side 214A, and the radial side of the second segment is a second radial side 214B. When forming the outer tube, the first and second segments are arranged adjacent to each other, and the first and second radial sides are adjacent parts. The first radial side has a first reinforcing rib 215A, which is injection molded and connected to the first segment. The connection part is as follows. Figure 5 In the h-section, the second radial side has a groove 2141B that mates with the other side of the first reinforcing rib, and the other side of the first reinforcing rib 215A is connected to the second radial side via adhesive through the groove 2141B on the second radial side; simultaneously, the second radial side has a second reinforcing rib 215B, which is injection molded and connected to the second tube sheet. The first radial side has a groove 2141A that mates with the other side of the second reinforcing rib, and the other side of the second reinforcing rib is connected to the first radial side via adhesive through the groove 2141A on the first radial side. The bonded portion is as follows: Figure 5 The k-part in the middle.

[0040] This design also has the advantage that the joints between multiple pipe segments are less prone to cracking, increasing the strength and service life of the MPP cable protection pipe.

[0041] Furthermore, there is a stainless steel retaining ring 4 with an opening 41 on the outside of the outer tube, which keeps the multiple tube segments in a clamped state.

[0042] The retaining ring keeps multiple pipe segments in a clamped state. That is, when not installed, the diameter of the retaining ring is smaller than the diameter of the outer pipe. After installation, the retaining ring keeps multiple pipe segments in a clamped state and also makes the outer pipe more secure.

[0043] Furthermore, there is a protective coating on the outside of the outer tube.

[0044] Examples 1A-6A Prepare the adhesive according to the following proportions (unit: kilograms, the same below). The adhesive described above was used to bond the inner and outer tubes of the MPP cable protection pipe. The performance statistics of the resulting MPP cable protection pipe are shown in the table below: Compared to other adhesives, it has better bonding performance, longer service life, and higher strength.

[0045] Examples 1B-6B Prepare the adhesive (second adhesive) according to the following ratio: (In this case, the adhesive in Examples 1A-6A is the first adhesive) Raw material name Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 2-Methyl-4-ethylimidazole 15 20 17 0 17 17 xylene 10 12 11 11 0 11 Epoxy resin 5 7 6 6 6 0 Dibutyl phthalate 7 10 8.5 0 8.5 8.5 Vinyl resin 8 10 9 9 0 0 Methylcellulose 8 10 9 9 9 9 stone powder 5 10 7.5 7.5 7.5 7.5 xylene 5 7 6 6 6 6 acetone 5 7 6 6 6 6 Dibutyl ester 5 7 6 6 6 6 Example Name Example 1B Example 2B Example 3B Example 4B Example 5B Example 6B The name of the second adhesive Second A adhesive Second B adhesive Second C adhesive Second D adhesive Second E adhesive Second F adhesive The adhesive described above is used for bonding the radial sides of adjacent segments of an MPP cable protection pipe, or for bonding the reinforcing ribs on the sides of adjacent segments.

[0046] The performance statistics of the obtained MPP cable protection pipe are as follows: Use the name of the adhesive Second A adhesive Second B adhesive Second C adhesive Second D adhesive Second E adhesive Second F adhesive Coefficient of resistance to cracking 1 1 1 0.95 0.95 0.91 Example Name Example 1C Example 2C Example 3C Example 4C Example 5C Example 6C Compared to other adhesives, it has better bonding performance, longer service life, and higher strength.

[0047] Example 1C The first A adhesive, the first B adhesive, and the first C adhesive prepared in Examples 1A-3A above; the second adhesive and 100-mesh butadiene rubber powder are mixed to form a surface spraying agent, wherein the surface spraying agent is prepared by mixing the adhesive and 100-mesh butadiene rubber powder at a mass ratio of 1:0.5-0.8 and spraying it onto the MPP cable protection pipe to form a protective coating, thereby obtaining the MPP cable protection pipe.

[0048] This MPP cable protection pipe has the advantages of higher strength, longer creepage distance, and less aging.

[0049] Example 2C The second adhesive A, the second adhesive B, and the second adhesive C prepared in Examples 1B-3B above are used; the second adhesive is mixed with 100-mesh butadiene rubber powder to form a surface spraying agent, wherein the surface spraying agent is prepared by mixing the second adhesive and 100-mesh butadiene rubber powder at a mass ratio of 1:0.5-0.8 and spraying it onto the MPP cable protection pipe to form a protective coating, thereby obtaining the MPP cable protection pipe.

[0050] This MPP cable protection pipe has the advantages of higher strength, longer creepage distance, and less aging.

[0051] Example 1D A surface coating agent is prepared by mixing 10-15 parts of polyvinyl alcohol powder, 20-25 parts of n-butyl acrylate, 20-22 parts of acrylic acid, 10-12 parts of methylcellulose, 3-5 parts of hydroxyl-terminated polydimethylsiloxane, 7-10 parts of sodium sulfate powder, 5-7 parts of methylhydroquinone powder, 3-5 parts of hydroquinone, 6-8 parts of 100-mesh cis-butadiene rubber powder, and 8-10 parts of 100-mesh ceramic powder. This mixture is then sprayed onto the MPP cable protection pipe to form a protective coating, thus obtaining the MPP cable protection pipe.

[0052] The MPP cable protection pipe has the advantages of higher strength, longer creepage distance, and less aging, and its performance is superior to the MPP cable protection pipe obtained in Example 1C above.

[0053] Example 1E Based on Examples 1A, 2A, and 3A, when the adhesive is applied between the inner and outer tubes, the temperature of the inner and outer tubes is 65-75°C, and the temperature of the adhesive is 25-30°C. This yields an MPP cable protection pipe, which is a 1EMPP cable protection pipe.

[0054] Example 2E Based on Examples 1A, 2A, and 3A, when the adhesive is applied between the inner and outer tubes, the temperature of both the inner and outer tubes is 30-35°C, and the temperature of the adhesive is also 30-35°C. This yields an MPP cable protection pipe, specifically a 2EMPP cable protection pipe.

[0055] Example 3E Based on Examples 1A, 2A, and 3A, when the adhesive is applied between the inner and outer tubes, the temperature of both the inner and outer tubes is 45-50°C, and the temperature of the adhesive is also 45-50°C. This yields an MPP cable protection pipe, specifically a 3EMPP cable protection pipe.

[0056] Compared to 2EMPP and 3EMPP cable protection pipes, 1EMPP cable protection pipes have the advantages of higher adhesive strength and stronger bonding between the inner and outer pipes.

[0057] Example 1F Based on Example 1D, an additional protective coating 5 is applied to the outside of the outer tube; when the protective coating is sprayed onto the outside of the outer tube, the temperature of the outer tube is 65-75°C, the temperature of the protective coating is 25-30°C, and the ambient temperature is maintained at 25-30°C for 12 hours after spraying is completed, while the ambient temperature slowly decreases from 55-60°C to 25-30°C.

[0058] We obtained an MPP cable protection pipe, which is a 1FMPP cable protection pipe.

[0059] Example 2F Based on Example 1D, there is an additional protective coating on the outside of the outer tube; when the protective coating is sprayed on the outside of the outer tube, the temperature of the outer tube is 60°C, the temperature of the protective coating is 60°C, and the ambient temperature is kept slowly decreasing to 35°C within 24 hours after the spraying is completed.

[0060] We obtained an MPP cable protection pipe, which is a 2FMPP cable protection pipe.

[0061] Example 3F Based on Example 1D, there is an additional protective coating on the outside of the outer tube; when the protective coating is sprayed on the outside of the outer tube, the temperature of the outer tube is 40°C, the temperature of the protective coating is 40°C, and the ambient temperature is kept slowly decreasing from 35°C within 24 hours after the spraying is completed.

[0062] We obtained an MPP cable protection pipe, which is a 3FMPP cable protection pipe.

[0063] Compared to 2FMPP and 3FMPP cable protection pipes, 1FMPP cable protection pipes have the advantages of higher protective layer strength and greater durability.

[0064] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. An MPP cable protection conduit, comprising an inner tube and an outer tube made of MPP, characterized in that: The inner tube contains coiled steel wires, which are wound steel wires. The outer tube includes multiple segments with arc-shaped cross-sections. These segments surround the outer tube to form the outer tube. Inside each segment are multiple straight steel wires parallel to the length of the segment. The inner sides of the multiple segments and the outer side of the inner tube are bonded together with adhesive, which is the first adhesive.

2. The MPP cable protection pipe according to claim 1, characterized in that: The tube segment has an arc-shaped outer surface, an arc-shaped inner surface, and a radial surface. An adhesive is applied between the radial surfaces of adjacent tube segments. This adhesive is a second adhesive. The radial surfaces of adjacent tube segments also have grooves for accommodating reinforcing ribs. The reinforcing ribs are also in these grooves and are bonded to the grooves with adhesive, which is a second adhesive.

3. The MPP cable protection pipe according to claim 2, characterized in that: There are at least two reinforcing ribs on the sides of adjacent segments. One side of each of the two reinforcing ribs is connected to the radial side of the two adjacent segments by injection molding. The other side of each of the two reinforcing ribs is bonded to the radial side of another segment with a second adhesive.

4. The MPP cable protection pipe according to claim 3, characterized in that: Outside the outer tube, there are stainless steel retaining rings with openings, which keep multiple tube segments in a clamped state.

5. The MPP cable protection pipe according to claim 4, characterized in that: There is also a protective coating on the outside of the outer tube.

6. The MPP cable protection pipe according to claim 5, characterized in that: The adhesive is a mixture of materials containing the following parts by weight; The composition includes 50-60 parts of viscous epoxy resin, 20-25 parts of emulsified polyvinyl acetate, 18-20 parts of viscous dihydroxy polydimethylsiloxane, 15-20 parts of xylene, 12-15 parts of nano-carbon powder, 8-10 parts of ethyl α-cyanoacrylate, 8-10 parts of boron nitride powder, 10-15 parts of thermoplastic elastomer, 3-5 parts of flame retardant, and 10-12 parts of coupling agent.

7. A method for manufacturing an MPP cable protection pipe, comprising an inner tube and an outer tube made of MPP, wherein the inner tube has coiled steel wire inside, the steel wire being wound steel wire, and the outer tube comprises multiple segments with an arc-shaped cross-section, each segment containing straight steel wire parallel to its length direction; the multiple segments are bonded to the outside of the inner tube with an adhesive, the adhesive being a first adhesive; the first adhesive is a mixture containing the following materials in parts by weight: 50- The mixture comprises 60 parts of emulsified polyvinyl acetate, 20-25 parts of viscous dihydroxypolydimethylsiloxane, 18-20 parts of xylene, 12-15 parts of 200-mesh nano carbon powder, 8-10 parts of ethyl α-cyanoacrylate, 8-10 parts of boron nitride powder, 10-15 parts of thermoplastic elastomer, 3-5 parts of flame retardant, and 10-12 parts of coupling agent mixture; when the adhesive is applied between the inner and outer tubes, the temperature of the inner and outer tubes is 65-75°C, and the temperature of the adhesive is 25-30°C.

8. The method for manufacturing an MPP cable protection pipe according to claim 1, wherein an adhesive is further applied to the outer surface of the outer pipe, in the gap between adjacent pipe segments, and this adhesive is a second adhesive; the pipe segments have an arc-shaped outer surface, an arc-shaped inner surface, and a radial surface, and the radial surface of adjacent pipe segments also has a groove for accommodating reinforcing ribs, and reinforcing ribs are further disposed in this groove, wherein the reinforcing ribs are bonded to the grooves with adhesive, and this adhesive is a second adhesive; the reinforcing ribs are steel wires; the outer surface of the steel wires also has a roughened layer; the... The second adhesive is a mixture of the following materials in parts by weight: 15-20 parts 2-methyl-4-ethylimidazolium, 10-12 parts xylene, 5-7 parts epoxy resin, 7-10 parts dibutyl phthalate, 8-10 parts vinyl resin, 8-10 parts methylcellulose, 5-10 parts stone powder, 5-7 parts xylene, 5-7 parts acetone, and 5-7 parts dibutyl phthalate; when the second adhesive is applied to the gap between adjacent segments or to the surface of the reinforcing rib, the temperature of the second adhesive is equal to the temperature of the outer tube.

9. An adhesive, wherein the adhesive is a mixture of the following materials in parts by weight: 50-60 parts of viscous epoxy resin, 20-25 parts of emulsion polyvinyl acetate, 18-20 parts of viscous dihydroxypolydimethylsiloxane, 15-20 parts of xylene, 12-15 parts of 200-mesh nano carbon powder, 8-10 parts of ethyl α-cyanoacrylate, 8-10 parts of boron nitride powder, 10-15 parts of thermoplastic elastomer, 3-5 parts of flame retardant, and 10-12 parts of coupling agent mixture.

10. A method for spraying a protective coating, wherein the protective coating is composed of the following materials in parts by weight: 10-15 parts polyvinyl alcohol powder, 20-25 parts n-butyl acrylate, 20-22 parts acrylic acid, 10-12 parts methylcellulose, 3-5 parts hydroxyl-terminated polydimethylsiloxane, 7-10 parts sodium sulfate powder, 5-7 parts methylhydroquinone powder, 3-5 parts hydroquinone, 6-8 parts 100-mesh cis-butadiene rubber powder, and 8-10 parts 100-mesh ceramic powder. When the protective coating is sprayed onto the outside of the MPP cable protection pipe, the temperature of the MPP cable protection pipe is 65-75°C, the temperature of the protective coating is 25-30°C, and the ambient temperature is maintained at 25-30°C for 12 hours after spraying, slowly cooling from 55-60°C to 25-30°C.

Images