Reversible thermochromic fiber reinforced pp-r composite pipe

Abstract

The utility model relates to a kind of reversible thermochromic fiber reinforced PP-R composite pipe material.It solves the technical problems that existing users cannot directly observe temperature state etc.It includes the pipe body being hollow, pipe body is three-layer structure and is sequentially provided with inner layer, intermediate layer and outer layer from inside to outside, inner layer is anti-permeation color-changing layer, intermediate layer is transition layer, outer layer is fiber-reinforced color-changing layer, the thickness of inner layer, intermediate layer and outer layer are equal.The advantage is that: realize pipeline state visual monitoring, outer layer uses reversible thermochromic material, inner layer uses irreversible thermochromic material, so that pipe material can change color with temperature change, user does not need instrument, can be directly judged in-situ fluid temperature state by naked eye, realize low-temperature icing or high-temperature overheating early warning, significantly improve safety.

Description

Technical Field

[0001] This utility model belongs to the field of composite pipe technology, specifically relating to a reversible thermochromic fiber-reinforced PP-R composite pipe. Background Technology

[0002] PP-R plastic pipes have become the mainstream product for building water supply, drainage, and heating systems due to their advantages such as corrosion resistance, lightweight, and high strength. However, in hot water transportation or heating applications, the pipe wall temperature may rise to a level sufficient to cause burns, such as above 50°C. Traditional pipes have a fixed color, making it impossible for users to visually determine their current temperature, posing a potential safety hazard. Furthermore, when abnormally high temperatures occur, such as exceeding 95°C, traditional pipes cannot record the overheating event, making subsequent accident diagnosis and maintenance difficult. Summary of the Invention

[0003] The purpose of this invention is to address the above-mentioned problems by providing a reversible thermochromic fiber-reinforced PP-R composite pipe.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a reversible thermochromic fiber-reinforced PP-R composite pipe, comprising a hollow pipe body, wherein the pipe body has a three-layer structure and is provided with an inner layer, a middle layer and an outer layer from the inside out, wherein the inner layer is a seepage-proof color-changing layer, the middle layer is a transition layer, and the outer layer is a fiber-reinforced color-changing layer, and the thickness of the inner layer, the middle layer and the outer layer are all equal.

[0005] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, the outer layer comprises a reversible thermochromic PP-R layer and a basalt fiber PP-R layer. The outer layer's color undergoes secondary reversible thermochromic changes within temperature ranges of 50-55℃ and 70-80℃, visually alerting users to the risk of burns and improving safety. These two temperature ranges also serve as a graded warning function, allowing users or maintenance personnel to quickly determine the status of the piping system and avoid misjudgments. The reversible thermochromic outer layer uses PP-R as a base material, adding 3%-5% by mass of composite microcapsule reversible color-changing dye, 0.1%-0.5% of heat stabilizer polyphosphine compound, and 2%-4% of anti-aging masterbatch. The addition of the heat stabilizer polyphosphine compound... Inhibiting thermal degradation reactions during processing ensures the stability of the material during high-temperature molding. Meanwhile, the anti-aging masterbatch mainly provides resistance to thermo-oxidative aging and light stability under long-term use conditions. The two work together to ensure the long-term stability of the performance and color of the pipe throughout its entire life cycle from processing to use. At the same time, the addition of the basalt fiber PP-R layer greatly improves the strength, stiffness and creep resistance of ordinary PP-R, enabling the pipe to withstand higher internal pressure and external impact, solving the problem of insufficient pressure resistance of pure PP-R pipes. Moreover, the basalt fiber PP-R layer has a lower thermal conductivity than the glass fiber PP-R layer.

[0006] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, the inner layer comprises an irreversible thermochromic PP-R layer and a leak-proof PP-R layer. The irreversible thermochromic PP-R layer can change color at approximately 95°C, and exceeding the maximum limit will leave a record.

[0007] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, the intermediate layer is a PP-R layer. This ensures the pipe's good processability and chemical stability.

[0008] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, the outer circumferentially outer surface is provided with an anti-scratch section. This anti-scratch section has several raised strips axially arranged along the length of the pipe, forming grooves between the raised strips. The raised strips constitute the first line of defense, effectively protecting the relatively fragile thermochromic outer layer from direct scratches during handling, construction, or external friction. The grooves and raised strips increase the friction on the pipe surface, making it easier to grip and install.

[0009] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, the raised strip has arc-shaped transition surfaces on both sides, and the raised strip is integrally connected to the outer layer. It is co-extruded and integrally formed with the pipe body, eliminating the risk of detachment, resulting in high structural strength. Furthermore, the arc-shaped transition surfaces avoid sharp stress concentration points, making it less prone to breakage.

[0010] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, a steel strip is provided between the intermediate layer and the inner layer by a spiral winding method.

[0011] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, the inner side of the steel strip has several sequentially distributed through holes, and these through holes have a regular hexagonal structure. The hexagonal through holes provide the maximum interlocking area and mechanical interlocking force. Molten PP-R material flows into the holes during co-extrusion, and after cooling, it firmly bonds the steel strip to the inner and outer plastic layers, completely eliminating the risk of delamination. Furthermore, the regular hexagonal shape is a structure that achieves the maximum area and most uniform stress distribution with the least amount of material, exhibiting excellent performance under multi-directional stress and being less prone to corner cracking.

[0012] In the aforementioned reversible thermochromic fiber-reinforced PP-R composite pipe, portions of the intermediate layer and the inner layer extend into the through-hole, respectively.

[0013] In the above-mentioned reversible thermochromic fiber-reinforced PP-R composite pipe, the pipe body is formed by three-layer co-extrusion.

[0014] Compared with existing technologies, the advantages of this utility model are as follows.

[0015] 1. This device enables visual monitoring of pipeline status. The outer layer uses a reversible thermochromic material, while the inner layer uses an irreversible thermochromic material, allowing the pipe to change color with temperature. Users can intuitively judge the temperature of the fluid inside the pipe with the naked eye without the need for instruments, thus achieving early warning of low-temperature freezing or high-temperature overheating and significantly improving safety.

[0016] 2. This device significantly enhances mechanical properties and durability. The outer layer also uses a basalt fiber PP-R layer, which greatly improves the rigidity, strength, creep resistance and dimensional stability of the pipe, enabling it to withstand higher internal pressure and external loads, and extending its service life. It is especially suitable for high-pressure scenarios such as high-rise water supply and high-temperature heating. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a structural cross-sectional view of the present invention.

[0019] Figure 3 This is a schematic diagram of the steel strip section in this utility model.

[0020] In the diagram: tube body 1, inner layer 11, middle layer 12, outer layer 13, scratch-resistant part 2, raised strip 21, groove 22, arc-shaped transition surface 23, steel strip part 3, through hole 31. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1-3 As shown, a reversible thermochromic fiber-reinforced PP-R composite pipe includes a hollow pipe body 1. The pipe body 1 has a three-layer structure and is provided with an inner layer 11, a middle layer 12 and an outer layer 13 from the inside out. The inner layer 11 is a seepage-proof and color-changing layer, the middle layer 12 is a transition layer, and the outer layer 13 is a fiber-reinforced and color-changing layer. The thicknesses of the inner layer 11, the middle layer 12 and the outer layer 13 are all equal.

[0023] Combination Figure 1 and Figure 2 As shown, the outer layer 13 has a reversible thermochromic PP-R layer and a basalt fiber PP-R layer. The color of the outer layer 13 can undergo secondary reversible thermochromic changes within temperature ranges of 50-55℃ and 70-80℃, visually alerting users to the risk of burns and improving safety. These two temperature ranges also serve as a graded warning function, allowing users or maintenance personnel to quickly determine the status of the piping system and avoid misjudgments. The reversible thermochromic outer layer uses PP-R as a base material, adding 3%-5% by mass of composite microcapsule reversible color-changing dye, 0.1%-0.5% of heat stabilizer polyphosphine compound, and 2%-4% anti-aging masterbatch. The addition of the heat stabilizer polyphosphine compound inhibits thermal degradation reactions during processing, preserving... The basalt fiber PP-R layer enhances the stability of the material during the high-temperature molding stage, while the anti-aging masterbatch mainly provides resistance to thermo-oxidative aging and light stability under long-term use conditions. The two work together to ensure the long-term stability of the performance and color of the pipe 1 throughout its entire life cycle from processing to use. At the same time, the addition of the basalt fiber PP-R layer greatly improves the strength, stiffness and creep resistance of ordinary PP-R, enabling the pipe 1 to withstand higher internal pressure and external impact, solving the problem of insufficient pressure resistance of pure PP-R pipes. The basalt fiber PP-R layer has a lower thermal conductivity than the glass fiber PP-R layer, and the basalt fiber PP-R layer can also be replaced by the aramid fiber PP-R layer.

[0024] The inner layer 11 has an irreversible thermochromic PP-R layer and a waterproof PP-R layer. The irreversible thermochromic PP-R layer can change color at around 95°C, and exceeding the maximum limit will leave a record.

[0025] Specifically, the intermediate layer 12 is a PP-R layer, which ensures good processability and chemical stability of the pipe 1.

[0026] Furthermore, the outer layer 13 is provided with an anti-scratch section 2 around its perimeter. The anti-scratch section 2 has several raised strips 21 arranged axially along the length of the pipe body 1, and grooves 22 are formed between the raised strips 21. The raised strips 21 constitute the first line of defense, which can effectively protect the relatively fragile thermochromic outer layer from direct scratches during handling, construction, or when subjected to external friction. The grooves 22 and the raised strips 21 increase the friction on the surface of the pipe 1, making it easier to grip and install.

[0027] Furthermore, the raised strip 21 has arc-shaped transition surfaces 23 on both sides, and the raised strip 21 is integrated with the outer layer 13. It is co-extruded and integrally formed with the tube body 1, eliminating the risk of detachment, resulting in high structural strength. The arc-shaped transition surfaces 23 also avoid sharp stress concentration points, making it less prone to damage.

[0028] like Figure 3 As shown, a steel strip 3 is provided between the intermediate layer 12 and the inner layer 11 by spiral winding.

[0029] The inner side of the steel strip section 3 has several sequentially arranged through holes 31, and the through holes 31 have a regular hexagonal structure. The regular hexagonal through holes 31 provide the maximum interlocking area and mechanical interlocking force. The molten PP-R material flows into the holes during co-extrusion, and after cooling, it firmly bonds the steel strip to the inner and outer plastic layers, completely eliminating the risk of delamination. At the same time, the regular hexagon is a structure that can obtain the maximum area and the most uniform stress distribution with the least amount of material. It performs well when subjected to multi-directional stress and is not prone to cracking at the corners.

[0030] Meanwhile, a portion of the intermediate layer 12 and a portion of the inner layer 11 extend into the through hole 31.

[0031] like Figure 2 As shown, tube 1 is formed by three-layer co-extrusion.

[0032] The principle of this embodiment is as follows: The outer layer 13 can undergo reversible thermochromic changes in the temperature range of 50-55℃ and 70-80℃. Meanwhile, the inner layer 11 can change color at around 95℃, and a record will be left if the maximum limit is exceeded. As the temperature rises, the color gradually lightens to colorless, and the process is reversible. Users or maintenance personnel can judge the temperature state of the medium inside the pipe with the naked eye without touching the pipe 1 or using tools, and can quickly locate it. When subjected to external friction, the raised strips 21 of the scratch-resistant part 2 can effectively protect the outer layer 13 from direct scratches, and the high impact resistance of the outer layer 13 can prevent the pipe from breaking.

[0033] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0034] Although this document uses terms such as tube body 1, inner layer 11, intermediate layer 12, outer layer 13, scratch-resistant part 2, raised strip 21, groove 22, arc-shaped transition surface 23, steel strip part 3, and through hole 31 frequently, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any kind of additional limitation would contradict the spirit of this utility model.

Claims

1. A reversible thermochromic fiber-reinforced PP-R composite pipe, comprising a hollow pipe body (1), characterized in that, The pipe body (1) has a three-layer structure and is provided with an inner layer (11), a middle layer (12) and an outer layer (13) from the inside to the outside. The inner layer (11) is a seepage-proof and color-changing layer, the middle layer (12) is a transition layer, and the outer layer (13) is a fiber-reinforced color-changing layer. The thicknesses of the inner layer (11), the middle layer (12) and the outer layer (13) are all equal.

2. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 1, characterized in that, The outer layer (13) has a reversible thermochromic PP-R layer and a basalt fiber PP-R layer.

3. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 1, characterized in that, The inner layer (11) has an irreversible thermochromic PP-R layer and an impermeable PP-R layer.

4. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 1, characterized in that, The intermediate layer (12) is a PP-R layer.

5. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 1, characterized in that, The outer layer (13) is provided with an anti-scratch part (2) on the outer periphery. The anti-scratch part (2) has a number of raised strips (21) arranged axially along the length direction of the tube body (1). The raised strips (21) form a groove (22) between them.

6. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 5, characterized in that, The raised strip (21) has arc-shaped transition surfaces (23) on both sides, and the raised strip (21) is integrated with the outer layer (13).

7. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 1, characterized in that, The intermediate layer (12) and the inner layer (11) are provided with a steel strip (3) by spiral winding.

8. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 7, characterized in that, The inner side of the steel strip (3) has a number of through holes (31) arranged in sequence, and the through holes (31) are in the form of regular hexagonal structure.

9. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 8, characterized in that, Parts of the intermediate layer (12) and parts of the inner layer (11) extend into the through hole (31).

10. The reversible thermochromic fiber-reinforced PP-R composite pipe according to claim 1, characterized in that, The tube body (1) is formed by three-layer co-extrusion.

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