Creep resistant aluminum plastic composite pipe

Abstract

The utility model provides a kind of anti-cravelling aluminium plastic composite pipe, it is related to aluminium plastic composite technical field, including inner plastic layer and outer plastic layer, the aluminium pipe layer being provided between inner plastic layer and outer plastic layer, the inner and outer two sides wall shot peening treatment of aluminium pipe layer divides aluminium pipe layer into integrally formed intermediate aluminium layer and the extension strengthening layer of the two sides of intermediate aluminium layer, the outside of the extension strengthening layer is provided with several micro-pits, several micro-pits are staggered distribution to make the outside of extension strengthening layer be orange peel, several micro-pits are staggered distribution to make the outside of extension strengthening layer be orange peel, inner plastic layer and outer plastic layer concave-convex cooperation are bonded in the inner and outer two sides of aluminium pipe layer.In the utility model, by setting micro-pit on the inner and outer wall of aluminium pipe layer, the bonding area between inner plastic layer and outer plastic layer and aluminium pipe layer can be greatly increased, the rigid constraint of aluminium pipe layer to inner plastic layer and outer plastic layer is increased, and the anti-cravelling performance of aluminium plastic composite pipe is improved.

Description

Technical Field

[0001] This utility model relates to the field of aluminum-plastic composite technology, specifically to an anti-creep aluminum-plastic composite pipe. Background Technology

[0002] Aluminum-plastic composite pipes have good thermal insulation properties, are not easily corroded on their inner and outer walls, have a smooth inner wall that provides very little resistance to fluid flow, and are easy to install because they can be bent at will. As water supply pipes, aluminum-plastic composite pipes can also be buried underground, such as the pipes used in underfloor heating systems. They can block gas penetration, and their core strength lies in the rigid constraint of the aluminum layer and the stress transmission mechanism of the composite structure, which makes their creep resistance significantly better than that of pure plastic pipes.

[0003] Existing aluminum-plastic composite pipes typically involve directly bonding a PPR layer onto an aluminum layer, resulting in low bonding strength and an inability to guarantee the anti-creep and anti-delamination properties of the aluminum-plastic pipe. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this utility model provides an anti-creep aluminum-plastic composite pipe, which solves the problems mentioned in the background section.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] An anti-creep aluminum-plastic composite pipe includes an inner plastic layer and an outer plastic layer, characterized in that: an aluminum tube layer is disposed between the inner plastic layer and the outer plastic layer, and the inner and outer sidewalls of the aluminum tube layer are shot-blasted to divide the aluminum tube layer into an integrally formed intermediate aluminum layer and extended reinforcing layers on both sides of the intermediate aluminum layer. The outer side of the extended reinforcing layer is provided with a plurality of micro-pits, and the inner plastic layer and the outer plastic layer are bonded to the inner and outer sides of the aluminum tube layer in a concave-convex fit.

[0009] Preferably, the strength of the extended reinforcing layer is greater than the strength of the intermediate aluminum layer.

[0010] Preferably, the micro-pits are distributed in an alternating pattern, giving the outer side of the extended reinforcing layer an orange peel-like appearance.

[0011] Preferably, a raised edge is formed between several of the micro-pits, and a thermal oxidation passivation layer is provided at the end of the raised edge.

[0012] (III) Beneficial Effects

[0013] This utility model provides a creep-resistant aluminum-plastic composite pipe. It has the following beneficial effects:

[0014] 1. In this utility model, shot peening creates several staggered orange peel-like micro-pits on the inner and outer surfaces of the aluminum tube layer. This increases the contact area between the inner and outer plastic layers and the aluminum tube layer. The increased contact area increases the bonding strength. In addition, the micro-pits in the aluminum tube layer can provide axial support for the inner and outer plastic layers that fit together, and disperse stress. This prevents the inner and outer plastic layers from over-creeping and delaminating under thermal alternating conditions, thus preventing the original rigid constraint of the aluminum tube layer on the inner and outer plastic layers from failing.

[0015] 2. Increasing the contact area can also increase the heat exchange efficiency between the aluminum tube layer and the inner and outer plastic layers, avoiding local creep caused by local thermal stress imbalance under alternating heat environment.

[0016] 3. In this utility model, the aluminum tube layer undergoes plastic deformation under the impact of shot peening. The sharp increase in dislocation density and the complexity of the dislocation structure inside the extended reinforcing layer make the strength of the extended reinforcing layer greater than that of the middle aluminum layer, which hinders further plastic deformation. This improves the yield strength of the aluminum tube layer, resists circumferential tensile deformation, and reduces the creep driving force of the inner and outer plastic layers. At the same time, the high-strength aluminum tube layer can be made thinner under the same pressure requirements, reducing processing costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an anti-creep aluminum-plastic composite pipe according to this utility model;

[0018] Figure 2 This is a cross-sectional view of the aluminum-plastic composite pipe in this utility model;

[0019] Figure 3 for Figure 2 Enlarged view of a portion of point A in the middle.

[0020] In the diagram: 1. Inner plastic layer; 2. Outer plastic layer; 3. Aluminum tube layer; 31. Intermediate aluminum layer; 32. Extension and reinforcement layer; 4. Micro-pits; 5. Thermal oxidation passivation layer. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0022] This utility model embodiment provides a creep-resistant aluminum-plastic composite pipe, such as Figure 1-3As shown, the structure includes an inner plastic layer 1 and an outer plastic layer 2. An aluminum tube layer 3 is disposed between the inner plastic layer 1 and the outer plastic layer 2. The inner and outer sidewalls of the aluminum tube layer 3 are shot-blasted, dividing the aluminum tube layer 3 into an integrally formed intermediate aluminum layer 31 and extended reinforcing layers 32 on both sides of the intermediate aluminum layer 31. The inner and outer sides of the aluminum tube layer 3 are shot-blasted, and under impact, the extended reinforcing layers 32 of the aluminum tube layer 3 undergo plastic deformation. The outer side of the extended reinforcing layers 32 is provided with a plurality of micro-pits 4, which are interlaced. The distribution gives the outer side of the extended reinforcing layer 32 an orange peel-like appearance. By impacting several micro-pits 4 into the inner and outer surfaces of the aluminum tube layer 3, the surface area of ​​the aluminum tube layer 3 is greatly increased compared to an unprocessed flat surface. This increases the contact area between the aluminum tube layer 3 and the inner plastic layer 1 and outer plastic layer 2. Increasing the contact area increases the bonding surface between the inner plastic layer 1 and outer plastic layer 2 and the aluminum tube layer 3, thereby increasing the overall rigid constraint of the aluminum tube layer 3 on the inner plastic layer 1 and outer plastic layer 2. This helps to prevent excessive creep under thermal alternation. The resulting delamination, along with the different orientations of the inner walls of the micro-pits 4, disperses thermal stress, resists circumferential tensile deformation, reduces the creep driving force of the inner plastic layer 1 and the outer plastic layer 2, and further avoids delamination caused by excessive thermal stress. In addition, the increased contact area can accelerate the heat exchange efficiency between the aluminum tube layer 3 and the inner and outer plastic layers 1 and 2. The aluminum tube layer 3 can conduct heat, quickly and evenly dispersing the heat of the inner and outer plastic layers 1 and 2, avoiding local creep caused by local overheating of the inner and outer plastic layers 1 and 2. A raised edge is formed between several of the micro-pits 4, and a thermally oxidized passivation layer 5 is provided at the end of the raised edge. The inner and outer plastic layers 1 and 2 are bonded to the inner and outer sides of the aluminum tube layer 3 with a concave-convex fit. Through high-temperature oxygen-controlled heat treatment, the sharp edges formed between two adjacent micro-pits 4 are treated to form an aluminum oxide layer. Increasing its curvature boundary can eliminate the stress concentrated at the sharp edge, and at the same time can block the corrosion of the external environment, so that the aluminum-plastic composite pipe can maintain a longer service life in high-temperature and high-humidity environments.

[0023] Under impact, the extended reinforcing layer 32, treated by shot peening, experiences a sharp increase in dislocation density and a more complex dislocation structure. This results in the strength of the extended reinforcing layer 32 exceeding that of the intermediate aluminum layer 31. The plastic deformation of the extended reinforcing layer 32 tends to extend, but it is constrained by the undeformed intermediate aluminum layer 31 below. This leads to residual compressive stress on the surface and corresponding tensile stress in the intermediate aluminum layer 31, achieving a balance. This increases the hardness and strength of the extended reinforcing layer 32, making it stronger than the intermediate aluminum layer 31. This also improves the yield strength of the aluminum tube layer 3, enhancing the creep resistance of the aluminum-plastic composite pipe. Furthermore, under the same pressure requirements, the high-strength aluminum tube layer 3 can be made thinner, reducing processing costs.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A creep resistant aluminum plastic composite pipe comprising an inner plastic layer and an outer plastic layer, characterized in that: An aluminum tube layer is provided between the inner plastic layer and the outer plastic layer. The inner and outer sidewalls of the aluminum tube layer are shot-blasted to divide the aluminum tube layer into an integrally formed intermediate aluminum layer and extended reinforcing layers on both sides of the intermediate aluminum layer. Several micro-pits are provided on the outer side of the extended reinforcing layer. The inner plastic layer and the outer plastic layer are bonded to the inner and outer sides of the aluminum tube layer with a concave-convex fit.

2. The creep resistant aluminum composite pipe of claim 1, wherein: The strength of the extended reinforcing layer is greater than that of the intermediate aluminum layer.

3. The creep resistant aluminum composite pipe of claim 2, wherein: The interlacing distribution of several of the aforementioned micro-pits gives the outer side of the extended reinforcing layer an orange peel-like appearance.

4. The creep resistant aluminum composite pipe of claim 3, wherein: A raised edge is formed between several of the micro-pits, and a thermal oxidation passivation layer is provided at the end of the raised edge.

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