Six-layer composite antibacterial oxygen barrier PPR pipe

Abstract

This utility model relates to a six-layer composite antibacterial and oxygen-barrier PPR pipe. It solves the technical problem that existing metal layers lose their pressure-bearing capacity when through-holes are made in the metal layer. The pipe includes a hollow pipe body with a six-layer structure, consisting of an antibacterial layer, an inner plastic layer, an inner adhesive layer, an aluminum strip layer, an outer adhesive layer, and an outer plastic layer, arranged sequentially from the inside out. The surface of the aluminum strip layer has several inwardly recessed pits that do not penetrate the aluminum strip layer, formed by laser etching. These pits are micron- or nanometer-sized, and the pit density is greater than 100 pores / cm². 2 The advantages are as follows: This device achieves surface etching treatment on the aluminum strip layer by applying laser etching technology, creating micropores on the surface of the aluminum strip layer. Compared with existing technologies, this not only improves the adhesive strength of the aluminum strip layer but also ensures its pressure-bearing capacity, significantly increasing the bonding strength between the aluminum strip layer and the inner and outer adhesive layers, thereby enhancing the overall reliability and service life of the six-layer composite pipe.

Description

Technical Field

[0001] This utility model belongs to the field of six-layer pipe technology, specifically relating to a six-layer composite antibacterial oxygen barrier PPR pipe. Background Technology

[0002] Existing pipes typically employ single-layer or simple multi-layer structures, such as single-layer PPR pipes or composite pipes with inner and outer aluminum cladding. Single-layer pipes generally lack sufficient strength and oxygen barrier properties, while conventional multi-layer pipes still have room for improvement in adhesion, high-temperature resistance, high-pressure performance, and hygienic properties. In multi-layer composite pipes, to enhance the bond between the metal and polymer layers, an adhesive layer with both bonding and media resistance properties needs to be coated at the interface. However, the direct bonding between the inner plastic layer and the metal layer, as well as between the outer plastic layer and the metal layer, via adhesive bonding can easily lead to delamination during actual production and use. While creating through-holes in the metal layer to allow the inner and outer plastics to fuse together can improve adhesion, these through-holes can also cause the metal layer to lose its pressure-bearing capacity.

[0003] To address the shortcomings of existing technologies, people have conducted long-term explorations and proposed various solutions. For example, Chinese patent literature discloses a mesh aluminum strip reinforced PP-R plastic-aluminum composite pipe [201120086776.1], which includes an inner plastic layer, an aluminum strip layer, and an outer plastic layer. The inner plastic layer and the aluminum strip layer, as well as the outer plastic layer and the aluminum strip layer, are bonded together by a hot melt adhesive layer. The aluminum strip layer has through holes.

[0004] The above solution has solved the problem of delamination that easily occurs when directly bonding with adhesive layers to some extent. However, the solution still has many shortcomings, such as the loss of pressure-bearing capacity of the metal layer due to the opening of through holes in the metal layer. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a six-layer composite antibacterial and oxygen-barrier PPR pipe.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a six-layer composite antibacterial and oxygen-barrier PPR pipe, comprising a hollow pipe body, wherein the pipe body has a six-layer structure and is provided sequentially from the inside out with an antibacterial layer, an inner plastic layer, an inner adhesive layer, an aluminum strip layer, an outer adhesive layer, and an outer plastic layer; the surface of the aluminum strip layer is provided with a plurality of inwardly recessed pits that do not penetrate the aluminum strip layer by laser etching, wherein the pits are at the micron or nanometer level and the pit density is greater than 100 pores / cm². 2The pits created by laser etching are far from penetrating the aluminum strip layer, thus ensuring the pressure-bearing capacity of the aluminum strip layer. At the same time, laser etching increases the surface roughness of the aluminum strip layer, achieving higher adhesive bonding strength and improving the adhesion between the aluminum strip layer and the inner and outer adhesive layers. In addition, an antibacterial layer is added to the innermost layer, further enhancing the hygiene and safety of the pipe in applications such as drinking water.

[0007] In the aforementioned six-layer composite antibacterial and oxygen-barrier PPR pipe, the pits form a uniformly distributed array of micropores on the surface of the aluminum strip layer. This uniformly distributed array of micropores is formed on the surface of the aluminum strip layer via a programmable path.

[0008] In the aforementioned six-layer composite antibacterial and oxygen-barrier PPR pipe, the surface roughness Ra value of the pits is 2.0 μm, the pore size of the pits is 50-100 μm, and the density of the pits is 100-200 pores / cm³. 2 When performing laser etching, pulsed lasers, fiber lasers, solid-state lasers, or CO2 lasers can be selected according to the application requirements. By utilizing energy density, repetition frequency, and scanning path, micron- or nano-scale pit distributions can be formed on the surface of the aluminum strip layer, thereby providing a larger bonding area for subsequent adhesive layers, forming a mechanical interlocking structure and improving adhesion.

[0009] In the aforementioned six-layer composite antibacterial and oxygen-barrier PPR pipe, both the inner and outer adhesive layers are in contact with the pits on the surface of the aluminum strip layer through coating or co-extrusion. A portion of the inner adhesive layer and a portion of the outer adhesive layer extend into the pits. The inner and outer adhesive layers, along with the laser-etched aluminum strip layer, are then melt-infiltrated into the surface pits through extrusion or thermal bonding, resulting in a tight bond and significantly improved adhesion strength.

[0010] In the aforementioned six-layer composite antibacterial oxygen barrier PPR pipe, both the outer and inner plastic layers are polypropylene raw material layers.

[0011] In the aforementioned six-layer composite antibacterial oxygen barrier PPR pipe, both the inner and outer adhesive layers are PP-based maleic anhydride adhesive layers.

[0012] In the aforementioned six-layer composite antibacterial and oxygen-barrier PPR pipe, the antibacterial layer comprises an inorganic silver ion layer and a porous silica layer. The antibacterial layer can be formed through co-extrusion, coating, or encapsulation. Nano-silver ions are selected as the antibacterial agent, and porous silica is used to prevent silver ion aggregation. A two-layer concentration gradient is employed to rapidly kill flowing microorganisms while maintaining sustained antibacterial activity. Furthermore, the type or concentration of the antibacterial agent and the ratio of the two-layer concentration gradient can be changed to adapt to specific drinking water or industrial liquid transportation needs.

[0013] In the aforementioned six-layer composite antibacterial and oxygen-barrier PPR pipe, the thickness of the antibacterial layer is 0.05-0.5 mm.

[0014] In the aforementioned six-layer composite antibacterial oxygen barrier PPR pipe, the thickness of the aluminum strip layer is 0.2-0.5 mm.

[0015] In the aforementioned six-layer composite antibacterial and oxygen-barrier PPR pipe, the outer plastic layer thickness is greater than the inner plastic layer thickness, the antibacterial layer thickness is less than the inner plastic layer thickness, the outer adhesive layer thickness is equal to the inner adhesive layer thickness, and the aluminum strip layer thickness is equal to or less than the inner adhesive layer thickness.

[0016] Compared with existing technologies, the advantages of this utility model are: This device uses laser etching technology to etch micropores into the aluminum strip layer, which, compared with existing technologies, improves the adhesive strength of the aluminum strip layer and ensures its pressure resistance. It also significantly enhances the bonding strength between the aluminum strip layer and the inner and outer adhesive layers, thereby increasing the overall reliability and service life of the six-layer composite pipe. Furthermore, the antibacterial layer with a double concentration gradient on the innermost side can effectively inhibit bacterial growth and improve the hygiene and safety of the transported medium in the long term. Attached Figure Description

[0017] Figure 1 This is a structural cross-sectional view of the present invention.

[0018] Figure 2 This is a schematic diagram of the surface of the aluminum strip layer in this utility model.

[0019] In the diagram: 1. Pipe body; 2. Antibacterial layer; 3. Inner plastic layer; 4. Inner rubber layer; 5. Aluminum strip layer; 51. Dent; 6. Outer rubber layer; 7. Outer plastic layer. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1-2 As shown, a six-layer composite antibacterial and oxygen-barrier PPR pipe includes a hollow pipe body 1. The pipe body 1 has a six-layer structure, consisting of an antibacterial layer 2, an inner plastic layer 3, an inner adhesive layer 4, an aluminum strip layer 5, an outer adhesive layer 6, and an outer plastic layer 7, arranged sequentially from the inside out. The surface of the aluminum strip layer 5 has several inwardly recessed pits 51 that do not penetrate the aluminum strip layer 5, formed by laser etching. The pits 51 are at the micrometer or nanometer scale, and the density of the pits 51 is greater than 100 pores / cm². 2The pits 51 created by laser etching are far from penetrating the aluminum strip layer 5, thus ensuring the pressure-bearing capacity of the aluminum strip layer 5. At the same time, laser etching increases the surface roughness of the aluminum strip layer 5, achieving higher adhesive bonding strength and improving the adhesion between the aluminum strip layer 5 and the inner adhesive layer 4 and the outer adhesive layer 6. In addition, the addition of an antibacterial layer 2 to the innermost layer further enhances the hygiene and safety of the pipe in applications such as drinking water.

[0022] The recesses 51 form a uniformly distributed array of micropores on the surface of the aluminum strip layer 5. A programmable path is used to form this uniformly distributed array of micropores on the surface of the aluminum strip layer 5.

[0023] Specifically, the surface roughness Ra of the pit 51 is 2.0 μm, the pore size of the pit 51 is 50-100 μm, and the density of the pit 51 is 100-200 pores / cm³. 2 When performing laser etching, pulsed laser, fiber laser, solid-state laser or CO2 laser can be selected according to the application requirements. By utilizing energy density, repetition frequency and scanning path, micron- or nano-scale pits 51 are distributed on the surface of aluminum strip layer 5, thereby providing a larger bonding area for subsequent adhesive layers, forming a mechanical interlocking structure to improve adhesion, and at the same time removing residual oxide particles or dust from the surface processing, and minimizing secondary surface contamination.

[0024] Furthermore, both the inner adhesive layer 4 and the outer adhesive layer 6 are in contact with the pits 51 on the surface of the aluminum strip layer 5 through coating or co-extrusion, with local portions of the inner adhesive layer 4 and the outer adhesive layer 6 extending into the pits 51. The inner adhesive layer 4 and the outer adhesive layer 6, together with the laser-etched aluminum strip layer 5, are melt-infiltrated into the surface pits 51 through extrusion or thermal bonding, forming a tight bond and significantly improving the adhesion strength.

[0025] Furthermore, both the outer plastic layer 7 and the inner plastic layer 3 are polypropylene raw material layers.

[0026] Meanwhile, both the inner adhesive layer 4 and the outer adhesive layer 6 are PP-based maleic anhydride adhesive layers.

[0027] Clearly, antibacterial layer 2 comprises an inorganic silver ion layer and a porous silica layer. Antibacterial layer 2 can be formed through co-extrusion, coating, or encapsulation. The antibacterial agent is selected as nano-silver ions, and porous silica is used to prevent silver ion aggregation. A two-layer concentration gradient is employed to rapidly kill flowing microorganisms while maintaining sustained antibacterial activity. Furthermore, the type or concentration of the antibacterial agent and the ratio of the two-layer concentration gradient can be changed in antibacterial layer 2 to adapt to specific drinking water or industrial liquid transportation needs.

[0028] Specifically, the thickness of antimicrobial layer 2 is 0.05-0.5 mm. Antimicrobial layer 2 contains a blend of antimicrobial agents to inhibit microbial growth. By employing a two-layer concentration gradient, it can quickly kill mobile microorganisms while maintaining sustained antimicrobial activity through slow release.

[0029] Specifically, the thickness of aluminum strip layer 5 is 0.2-0.5 mm.

[0030] In addition, the outer plastic layer 7 is thicker than the inner plastic layer 3, the antibacterial layer 2 is thinner than the inner plastic layer 3, the outer adhesive layer 6 is equal to the inner adhesive layer 4, and the aluminum strip layer 5 is equal to or less than the inner adhesive layer 4.

[0031] Each layer is extruded or coated separately using a multi-extruder or stacking process: The first extruder melts polypropylene raw material and extrudes it to form the inner plastic layer 3; the second extruder heats and melts PP-based maleic anhydride adhesive and co-extrudes it onto the outer surface of the inner plastic layer 3 to form the inner adhesive layer 4; the third extruder coats antibacterial material onto the inner surface of the inner plastic layer 3 to form the antibacterial layer 2; then the aluminum strip layer 5, which is laser-etched, is bonded, shaped, and welded to the inner adhesive layer 4; at the same time, the third extruder melts PP-based maleic anhydride adhesive and coats it onto the outer surface of the aluminum strip layer 5 to form the outer adhesive layer 6; finally, the fourth extruder melts polypropylene raw material and extrudes it onto the outer surface of the outer adhesive layer 6 to form the outer plastic layer 7.

[0032] The principle of this embodiment is as follows: Recesses 51 are machined on the surface of aluminum strip layer 5 by laser etching. Parts of inner adhesive layer 4 and outer adhesive layer 6 extend into the recesses 51. The design of recesses 51 does not affect the pressure bearing capacity of aluminum strip layer 5 itself, but also improves the adhesive strength between aluminum strip layer 5 and adhesive layer, thereby improving the overall stability of pipe body 1. Inner plastic layer 3 and outer plastic layer 7 are both polypropylene material layers. Outer plastic layer 7 is in direct contact with the external environment, which can resist external damage, delay aging, and protect the intermediate functional layer. Inner plastic layer 3 serves as the base of antibacterial layer 2. The rigidity and toughness of polypropylene can support the ultra-thin antibacterial layer 2, preventing the antibacterial layer 2 from being damaged by water pressure or installation friction, while providing basic pressure bearing capacity for the inner layer of the pipe. Antibacterial layer 2 is used to inhibit bacterial growth, protect the cleanliness of the medium, and provide basic structural support.

[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 frequently uses terms such as pipe body 1, antibacterial layer 2, inner plastic layer 3, inner rubber layer 4, aluminum strip layer 5, pit 51, outer rubber layer 6, and outer plastic layer 7, 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 additional limitation would contradict the spirit of this utility model.

Claims

1. A six-layer composite antibacterial and oxygen-barrier PPR pipe, comprising a hollow pipe body (1), characterized in that, The pipe body (1) has a six-layer structure, consisting of an antibacterial layer (2), an inner plastic layer (3), an inner adhesive layer (4), an aluminum strip layer (5), an outer adhesive layer (6), and an outer plastic layer (7) arranged sequentially from the inside out. The surface of the aluminum strip layer (5) is provided with several inwardly recessed pits (51) that do not penetrate the aluminum strip layer (5) by laser etching. The pits (51) are at the micron or nanometer level and the density of the pits (51) is greater than 100 pores / cm. 2 .

2. The six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, The pits (51) form a uniformly distributed array of micropores on the surface of the aluminum strip layer (5).

3. The six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, The surface roughness Ra value of the pit (51) is 2.0 μm, the pore size of the pit (51) is 50-100 μm, and the density of the pit (51) is 100-200 pores / cm³. 2 .

4. The six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, The inner adhesive layer (4) and the outer adhesive layer (6) are in contact with the pits (51) on the surface of the aluminum strip layer (5) by coating or co-extrusion. A portion of the inner adhesive layer (4) and a portion of the outer adhesive layer (6) extend into the pits (51).

5. The six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, Both the outer plastic layer (7) and the inner plastic layer (3) are polypropylene raw material layers.

6. The six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, Both the inner adhesive layer (4) and the outer adhesive layer (6) are PP-based maleic anhydride adhesive layers.

7. The six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, The antibacterial layer (2) has an inorganic silver ion layer and a porous silica layer.

8. The six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, The thickness of the antibacterial layer (2) is 0.05-0.5 mm.

9. A six-layer composite antibacterial and oxygen-barrier PPR pipe according to claim 1, characterized in that, The thickness of the aluminum strip layer (5) is 0.2-0.5 mm.

10. A six-layer composite antibacterial oxygen-barrier PPR pipe according to claim 1, characterized in that, The outer plastic layer (7) is thicker than the inner plastic layer (3), the antibacterial layer (2) is thinner than the inner plastic layer (3), the outer adhesive layer (6) is thicker than the inner adhesive layer (4), and the aluminum strip layer (5) is thicker than or less than the inner adhesive layer (4).

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