Method and apparatus for manufacturing collapse resistant hbpe pipe

Abstract

The application discloses a manufacturing method and device of an anti-collapse HBPE pipe, relates to the technical field of pipe preparation, and realizes synchronous composite molding of a five-layer structure of an inner layer, a first bonding layer, a barrier layer, a second bonding layer and an outer layer by adopting a continuous extrusion-gluing-extrusion-gluing-extrusion process through the arrangement of a first extrusion molding mechanism, a first gluing mechanism, a second extrusion molding mechanism, a second gluing mechanism and a third extrusion molding mechanism. The interface bonding between layers is completed by corresponding bonding layers in a high-temperature molten state, instead of secondary composite or bonding after the layers are cooled and solidified, so that the interlayer bonding strength is improved. Even if the pipe is subjected to external pressure, temperature change or long-term internal pressure, the layers will not have obvious peeling or separation tendency, the risk of layering collapse is effectively reduced, and the long-term safe operation reliability of the HBPE high-barrier inner lining pipe in oil field, gas pipeline repair and other scenes is ensured.

Description

Technical Field

[0001] This invention relates to the field of pipe manufacturing technology, and in particular to a method and apparatus for manufacturing anti-collapse HBPE pipe. Background Technology

[0002] HBPE high-barrier lining pipe is a multi-layer composite olefin pipe designed specifically for pipeline repair and protection. Its core advantage lies in solving the problem of high gas permeability of traditional pipes. It is commonly used in pipeline lining repair in oil fields, gas fields and other fields.

[0003] HBPE high-barrier liner pipes are mostly multi-layered pipes, extruded by a co-extrusion machine. In existing technology, HBPE high-barrier liner pipes are typically manufactured using a multi-layer co-extrusion method. While this method can produce HBPE pipes, the fact that each layer is formed separately during the actual manufacturing process means that the entire HBPE pipe is at risk of delamination collapse during subsequent use. This leads to pipe blockage due to delamination collapse, affecting the safe operation of the HBPE pipe. Summary of the Invention

[0004] The main objective of this invention is to propose a method and apparatus for manufacturing anti-collapse HBPE pipes, aiming to solve the technical problem that in the actual manufacturing process of existing technology, since each pipe layer is formed in layers, the entire HBPE pipe is at risk of layer collapse during subsequent use. This leads to the risk of pipe blockage due to layer collapse during subsequent use, affecting the safe operation of HBPE pipes.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a manufacturing apparatus for anti-collapse HBPE pipes, the manufacturing apparatus comprising: sequentially and coaxially arranged along a first direction:

[0006] The first extrusion molding mechanism has a first extrusion molding channel for extruding to form an inner layer, and the first extrusion molding mechanism is connected to the first hopper;

[0007] A first adhesive coating mechanism is used to coat the outer wall of the inner layer with a first adhesive layer. The first adhesive coating mechanism includes a second mounting base, a first rotary drive assembly, and a first adhesive coating component. The second mounting base is mounted on the side of the first extrusion molding mechanism away from the first hopper. A first adhesive coating space is formed in the second mounting base and is coaxially arranged with the first extrusion molding channel. The first rotary drive assembly is mounted on the second mounting base, and the first adhesive coating component is mounted on the first rotary drive assembly. The first adhesive coating component is disposed facing the first adhesive coating space. The first rotary drive assembly can drive the first adhesive coating component to rotate around the first adhesive coating space so that the first adhesive coating component coats the outer wall of the inner layer that passes through the first extrusion molding channel and the first adhesive coating space with the first adhesive layer.

[0008] The second extrusion molding mechanism has a second extrusion molding channel, the second extrusion molding mechanism is connected to the second hopper, and the diameter of the second extrusion molding channel is larger than that of the first extrusion molding channel.

[0009] A second adhesive application mechanism is used to apply a second adhesive layer to the outer wall of the barrier layer; and

[0010] The third extrusion molding mechanism has a third extrusion molding channel. The third extrusion molding mechanism is connected to the first hopper through a pipe. The diameter of the third extrusion molding channel is larger than that of the second extrusion molding channel.

[0011] The technical solution of this invention, by setting up a first extrusion molding mechanism, a first adhesive coating mechanism, a second extrusion molding mechanism, a second adhesive coating mechanism, and a third extrusion molding mechanism, achieves simultaneous composite molding of a five-layer structure consisting of an inner layer, a first adhesive layer, a barrier layer, a second adhesive layer, and an outer layer through a sequential and continuous extrusion-adhesion-extrusion-adhesion-extrusion process. Each layer is bonded at the interface through its corresponding adhesive layer in a high-temperature molten state, rather than undergoing secondary composite molding or bonding after each layer has cooled and solidified, thus significantly improving the interlayer bonding strength. During subsequent use, even if the pipe is subjected to external pressure, temperature changes, or long-term internal pressure, there will be no significant tendency for peeling or separation between the layers, effectively reducing the risk of delamination and collapse, and avoiding problems such as pipe blockage or reduced flow capacity caused by interlayer separation. This ensures the long-term safe and reliable operation of HBPE high-barrier liner pipes in scenarios such as oil fields and gas pipeline repair. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0013] Figure 1 A schematic diagram of the manufacturing apparatus for anti-collapse HBPE pipe provided by the present invention;

[0014] Figure 2 This is a schematic diagram of the internal structure of the manufacturing apparatus as an example of the present invention;

[0015] Figure 3 for Figure 2 A schematic diagram of the first extrusion molding mechanism in the example;

[0016] Figure 4 for Figure 3 A schematic diagram of the structure of the first extrusion molding mechanism and the first coating mechanism in the example;

[0017] Figure 5 for Figure 3 Another structural schematic diagram of the first extrusion molding mechanism and the first coating mechanism in the example;

[0018] Figure 6 for Figure 2 A schematic diagram of the first adhesive application mechanism in the example;

[0019] Figure 7 for Figure 2 A schematic diagram of the second adhesive application mechanism in the example;

[0020] Figure 8 for Figure 2 Another structural schematic diagram of the first extrusion molding mechanism in the example;

[0021] Figure 9 This is a flowchart illustrating a method for manufacturing an anti-collapse HBPE pipe, as exemplified by the present invention.

[0022] Explanation of icon numbers:

[0023] 100. First extrusion molding mechanism; 110. First extrusion molding channel; 200. First adhesive coating mechanism; 210. Second mounting base; 220. First adhesive coating space; 230. First rotary drive assembly; 240. First adhesive coating component; 300. Second extrusion molding mechanism; 400. Second adhesive coating mechanism; 500. Third extrusion molding mechanism; 231. First rotary bearing; 232. First gear ring; 233. First drive motor; 234. First transmission gear; 250. First connecting bracket; 260. Second connecting bracket; 270. First telescopic component; 310. Second extrusion molding channel; 120. First extruded component; 130. First feeding channel; 140. Pipe extrusion 160. Molding end; 170. Feeding end; 180. Guide shaft; 190. First mounting base; 320. First rotary drive component; 330. Second extruded part; 410. Fourth mounting base; 420. Second adhesive application space; 430. Second rotary drive assembly; 440. Second adhesive application component; 431. Second rotary bearing; 432. Second gear ring; 433. Second drive motor; 434. Second transmission gear; 450. Third connecting bracket; 460. Fourth connecting bracket; 470. Second telescopic component; 510. Third extrusion molding channel; 520. Fifth mounting base; 530. Third extruded part; 540. Screw; 550. Third feeding channel.

[0024] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0027] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] During the manufacturing process of HBPE high-barrier liner pipes, the inner layer, barrier layer and outer layer are formed by a layered extrusion process. The interfacial bonding strength between the layers is insufficient, which leads to interlayer separation and structural collapse in the pipe during subsequent use, affecting the structural integrity of the pipeline and the continuity of fluid transportation.

[0029] For example, in the lining repair of oilfield pipelines, HBPE high-barrier linings are installed inside existing pipelines to provide gas barrier functionality. Under high-pressure oil and gas transportation conditions, poor interfacial bonding between the inner layer and the barrier layer can lead to localized separation, forming tiny gaps. These gaps gradually enlarge, causing partial blockage of the fluid passage and reducing the stability of system operation.

[0030] This invention proposes a method and apparatus for manufacturing anti-collapse HBPE pipes.

[0031] Please see Figures 1 to 9 For ease of understanding, this is a manufacturing apparatus for an anti-collapse HBPE pipe. The manufacturing apparatus includes components coaxially arranged sequentially along a first direction:

[0032] The first extrusion molding mechanism 100 has a first extrusion molding channel 110 for extruding and forming an inner layer, and the first extrusion molding mechanism 100 is connected to the first hopper;

[0033] A first adhesive coating mechanism 200 is used to coat a first adhesive layer onto the outer wall of an inner layer. The first adhesive coating mechanism 200 includes a second mounting base 210, a first rotary drive assembly 230, and a first adhesive coating component 240. The second mounting base 210 is mounted on the side of the first extrusion molding mechanism 100 away from the first hopper. A first adhesive coating space 220 is formed in the second mounting base 210 and is coaxially arranged with the first extrusion molding channel 110. The first rotary drive assembly 230 is mounted on the second mounting base 210, and the first adhesive coating component 240 is mounted on the first rotary drive assembly 230. The first adhesive coating component 240 is disposed facing the first adhesive coating space 220. The first rotary drive assembly 230 can drive the first adhesive coating component 240 to rotate around the first adhesive coating space 220 so that the first adhesive coating component 240 coats the outer wall of the inner layer that passes through the first extrusion molding channel and the first adhesive coating space 220 with the first adhesive layer.

[0034] The second extrusion molding mechanism 300 has a second extrusion molding channel 310. The second extrusion molding mechanism 300 is connected to the second hopper. The diameter of the second extrusion molding channel 310 is larger than that of the first extrusion molding channel 110.

[0035] The second adhesive application unit 400 is used to apply a second adhesive layer to the outer wall of the barrier layer; and,

[0036] The third extrusion molding mechanism 500 has a third extrusion molding channel 510. The third extrusion molding mechanism 500 is connected to the first hopper through a pipe. The diameter of the third extrusion molding channel 510 is larger than that of the second extrusion molding channel 310.

[0037] Specifically, the manufacturing apparatus for anti-collapse HBPE pipe provided in this application is provided with a first extrusion molding mechanism 100, a first adhesive coating mechanism 200, a second extrusion molding mechanism 300, a second adhesive coating mechanism 400 and a third extrusion molding mechanism 500 arranged coaxially along a first direction. The mechanisms are continuously coaxially connected through corresponding guide, support or transition structures so that the pipe blank maintains a stable axial movement trajectory during the extrusion process.

[0038] The first extrusion molding mechanism 100 is connected to the first hopper and has a first extrusion molding channel 110 inside. The HBPE matrix raw material from the first hopper is heated, plasticized, and metered, and then extruded through the first extrusion molding channel 110 to form a continuous inner layer preform. The outer diameter of the inner layer preform is limited by the outlet size of the first extrusion molding channel 110, and it immediately enters the subsequent first coating mechanism 200 after leaving the first extrusion molding mechanism 100.

[0039] The first adhesive application mechanism 200 is located on the side of the first extrusion molding mechanism 100 away from the first hopper. A first adhesive application space 220 is formed within its second mounting base 210. This first adhesive application space 220 is strictly coaxial with the first extrusion molding channel 110 to ensure that the inner layer preform can pass through the space without eccentricity or obstruction. A first rotary drive assembly 230 is mounted on the second mounting base 210. A first adhesive application component 240 is fixedly connected to the output end of the first rotary drive assembly 230 and is positioned towards the central axis of the first adhesive application space 220. During the continuous passage of the inner layer preform through the first adhesive application space 220, the first rotary drive assembly 230 drives the first adhesive application component 240 to rotate uniformly around the central axis of the first adhesive application space 220. The first adhesive application component 240 maintains stable contact or a small gap contact with the outer wall of the inner layer preform, thereby uniformly and continuously coating the first adhesive layer onto the outer wall surface of the inner layer. The coating thickness of the first adhesive layer can be precisely controlled by adjusting the relative position, rotation speed, and adhesive supply rate of the first adhesive application component 240.

[0040] Subsequently, the inner tube preform with the first adhesive layer directly enters the second extrusion molding mechanism 300. The second extrusion molding mechanism 300 is connected to the second hopper, and the diameter of its second extrusion molding channel 310 is larger than the diameter of the first extrusion molding channel 110. The barrier layer material supplied by the second hopper is plasticized and then extruded in the second extrusion molding channel 310 to coat the outside of the inner tube preform, forming a continuous barrier layer. Because the diameter of the second extrusion molding channel 310 is larger, the barrier layer tightly coats the outside of the first adhesive layer with a certain radial thickness. The first adhesive layer plays a role in bonding the inner layer and the barrier layer during this coating process.

[0041] After the barrier layer is formed, the tube blank continues to move forward into the second adhesive application mechanism 400. The structure of the second adhesive application mechanism 400 is basically the same as that of the first adhesive application mechanism 200, including a corresponding mounting base, a rotary drive assembly, and a second adhesive application component 440. Under the rotary drive, the second adhesive application component 440 rotates around the axis of the tube blank, uniformly applying the second adhesive layer to the outer surface of the barrier layer. The application of the second adhesive layer also adopts a rotary contact method to ensure uniform coating thickness, no bubbles, and no missed coating, thereby providing a reliable interface for the subsequent bonding of the outer layer.

[0042] Finally, the tube blank with the second adhesive layer enters the third extrusion molding unit 500. The third extrusion molding unit 500 is connected to the first hopper via a pipe, meaning its raw material also originates from the HBPE matrix material in the first hopper. The diameter of the third extrusion molding channel 510 is larger than that of the second extrusion molding channel 310, so the third extrusion molding unit 500 extrudes the HBPE material and coats it onto the outside of the barrier layer, forming a continuous outer layer. This outer layer and the barrier layer are firmly bonded together by the second adhesive layer.

[0043] In this embodiment, a five-layer composite structure consisting of an inner layer, a first adhesive layer, a barrier layer, a second adhesive layer, and an outer layer is simultaneously formed through a sequential extrusion-coating-extrusion-coating-extrusion process. Each layer is bonded at the interface through its corresponding adhesive layer while in a high-temperature molten state, rather than undergoing secondary bonding or fusion after cooling and solidification. This significantly improves the interlayer bonding strength. During subsequent use, even when the pipe is subjected to external pressure, temperature changes, or long-term internal pressure, there is no significant tendency for peeling or separation between the layers. This effectively reduces the risk of delamination and collapse, avoiding pipe blockage or reduced flow capacity due to interlayer separation, and ensuring the long-term safe and reliable operation of HBPE high-barrier liner pipes in scenarios such as oil fields and gas pipeline repair.

[0044] In one embodiment, the second mounting base 210 extends in a direction away from the first extrusion molding mechanism 100 and forms a first mounting position, and the first adhesive application space 220 passes through the first mounting position along a first direction and extends out of the second mounting base 210;

[0045] The first rotary drive assembly 230 includes:

[0046] The first rotary bearing 231 is sleeved on the outer periphery of the first mounting position along the first direction, and the first rotary bearing 231 can rotate around the first adhesive space 220 outside the first direction.

[0047] The first gear ring 232 is mounted on the outer periphery of the first rotary bearing 231. The first gear ring 232 can rotate around the first rotary bearing 231 in a first direction outside the first adhesive application space 220. The first adhesive application part 240 is mounted on the side of the first gear ring 232 away from the second mounting seat 210.

[0048] A first drive motor 233 is mounted on a second mounting base 210, and the output end of the first drive motor 233 extends in a first direction away from the second mounting base 210; and...

[0049] The first transmission gear 234 is installed at the output end of the first drive motor 233. The first transmission gear 234 meshes with the first gear ring 232. The first drive motor 233 can drive the first transmission gear 234 to drive the first gear ring 232 to rotate around the first direction through the first rotary bearing 231, so that the first adhesive applicator 240 can rotate around the first adhesive application space 220 and apply adhesive.

[0050] Specifically, the second mounting base 210 extends away from the first extrusion molding mechanism 100 and forms a first mounting position. The first adhesive application space 220 passes through the first mounting position along the first direction and extends out of the outer end face of the second mounting base 210, so that the outlet of the first extrusion molding channel 110 with the inner tube blank can smoothly pass through the first adhesive application space 220 and maintain the axis alignment and stability during the continuous advance of the tube blank.

[0051] A first rotary bearing 231 is sleeved on the outer peripheral surface of the first mounting position along a first direction. The inner ring of the first rotary bearing 231 is precisely fitted and interference-fitted with the outer cylindrical surface of the first mounting position, while the outer ring can rotate stably around the first direction, i.e., the tube blank axis. A first gear ring 232 is mounted and fixed on the outer periphery of the first rotary bearing 231, with its teeth facing radially outward. The first gear ring 232 rotates synchronously with the first rotary bearing 231 around the outer side of the first adhesive application space 220. A first adhesive application component 240 is fixedly mounted on the side of the first gear ring 232 away from the second mounting seat 210, i.e., at the axial outer end face of the first gear ring 232, so that the position of the first adhesive application component 240 is near the extension of the first adhesive application space 220 and facing the central axis.

[0052] The first drive motor 233 is mounted and fixed at a suitable position on the second mounting base 210, and its output shaft extends away from the second mounting base 210 along the first direction. The first transmission gear 234 is mounted on the output shaft of the first drive motor 233, and the teeth of the first transmission gear 234 form a stable meshing relationship with the teeth of the first gear ring 232. When the first drive motor 233 is powered on, its output end drives the first transmission gear 234 to rotate. The first transmission gear 234 drives the first gear ring 232 to rotate through tooth surface meshing. The first gear ring 232 then drives the outer ring of the first rotary bearing 231 to rotate synchronously around the first direction, thereby causing the first adhesive application part 240 fixed on the first gear ring 232 to rotate continuously around the central axis of the first adhesive application space 220.

[0053] In the actual manufacturing process of HBPE pipes, the inner layer preform immediately enters and passes through the first adhesive coating space 220 after being extruded from the first extrusion molding channel 110. The first drive motor 233 operates at a set speed, and the first adhesive coating component 240 rotates synchronously around the preform axis with the first gear ring 232 and the first rotary bearing 231, maintaining a stable contact or micro-gap contact state between its working end and the outer wall of the inner layer preform. During this rotation, the first adhesive coating component 240 continuously and uniformly transfers and coats the supplied first adhesive layer material onto the outer wall surface of the inner layer preform. Because the first adhesive coating component 240 adopts a rotational coating method around the preform axis, rather than static brushing or spraying, it can achieve 360° full coverage and no dead angle coating distribution while the preform moves forward at a uniform speed, avoiding axial stripes or local missed coating phenomena that may occur in traditional linear adhesive coating methods, thereby ensuring the uniformity of the first adhesive layer thickness and the consistency of interface wetting.

[0054] In this embodiment, the specific structure of the first rotary drive assembly 230 enables the first adhesive applicator 240 to obtain stable low-speed, high-torque rotary power. Furthermore, the entire rotating component is located on the outer periphery of the first adhesive applicator space 220, avoiding the risk of contamination or scratches that might result from the drive component directly intruding into the tube blank channel. Simultaneously, the first rotary bearing 231 effectively isolates the friction between the rotational motion and the fixed mounting base, ensuring that the second mounting base 210 and the first adhesive applicator space 220 remain stationary and coaxial. This allows the inner tube blank to maintain a stable, linear forward trajectory without interference from additional radial forces as it passes through the first adhesive applicator space 220.

[0055] In one embodiment, the meshing of the first transmission gear 234 and the first gear ring 232 adopts a helical gear structure. The helical gear meshing has a high degree of overlap and smoothness, which can significantly reduce vibration and noise during operation and is beneficial to maintaining the stability and repeatability of the coating thickness in long-term continuous production.

[0056] The first rotary bearing 231 is selected from deep groove ball bearings or angular contact ball bearings, and is equipped with axial and radial preload measures to further improve the rotational accuracy and rigidity of the first rotary bearing 231 under high speed or load conditions, and ensure that the contact pressure fluctuation between the first adhesive coating part 240 and the outer wall of the tube blank is controlled within a minimum range during rotary coating, thereby obtaining a higher quality first adhesive layer coating effect.

[0057] In one embodiment, the first gear ring 232 has a first hinge position on the side opposite to the second mounting base 210;

[0058] The first adhesive application unit 200 also includes:

[0059] The first connecting bracket 250 is hinged to the first hinge position, and the first connecting bracket 250 extends out of the first mounting position along the first direction in a direction away from the second mounting base 210.

[0060] A second connecting bracket 260, one end of which is hinged to the end of the first connecting bracket 250 away from the second mounting base 210, and the other end extending toward the first adhesive application space 220; a first adhesive application member 240 is hinged to the end of the second connecting bracket 260 away from the first connecting bracket 250, and the first adhesive application member 240 is rotatable relative to the second connecting bracket 260; and,

[0061] The first telescopic member 270 has two ends hinged to the first connecting bracket 250 and the second connecting bracket 260 respectively. The first telescopic member 270 can drive the second connecting bracket 260 to rotate around the first connecting bracket 250 so that the first adhesive applicator 240 can move closer to or further away from the first adhesive applicator space 220.

[0062] Specifically, the first gear ring 232 has a first hinge position on the side opposite to the second mounting base 210. This first hinge position typically adopts a structure of multiple hinge lugs distributed circumferentially or a single annular hinge boss to form a reliable rotational fit with the subsequent connecting bracket.

[0063] The first connecting bracket 250 is hinged to the first hinge position via a pin or hinge pin. The main body of the first connecting bracket 250 extends away from the second mounting base 210 along the first direction, i.e., the tube blank's forward direction, and exceeds the axial outer end of the first mounting position by a certain length, thereby reserving sufficient radial adjustment space for the arrangement of subsequent components. One end of the second connecting bracket 260 is rotatably connected to the end of the first connecting bracket 250 away from the second mounting base 210 via another set of hinge pins, while the other end of the second connecting bracket 260 extends towards the central axis of the first adhesive application space 220. The first adhesive application component 240 is hinged to this extended end of the second connecting bracket 260 via a bearing or rotating shaft. The first adhesive application component 240 can swing or rotate adaptively relative to the second connecting bracket 260 around its own mounting axis at a limited angle to better fit the outer wall of inner tube blanks of different diameters.

[0064] The two ends of the first telescopic member 270 are connected to the middle positions of the first connecting bracket 250 and the second connecting bracket 260 via ball joints or fork-type hinge structures, respectively. The first telescopic member 270 typically employs controllable linear drive elements such as electro-hydraulic actuators, electric actuators, or servo cylinders. In actual operation, the first telescopic member 270 extends or shortens according to process requirements. Its linear displacement drives the second connecting bracket 260 to swing around the hinge axis of the first connecting bracket 250 through the hinge points at both ends, thereby causing the first adhesive applicator 240 to move radially closer to or away from the central axis of the first adhesive application space 220.

[0065] During the manufacturing process, when the inner tube blank is extruded from the first extrusion molding channel 110 and enters the first adhesive coating space 220, the first telescopic component 270 precisely adjusts its extension and retraction according to the preset outer diameter specification of the tube blank or the real-time detected tube diameter data. For example, when the outer diameter of the tube blank fluctuates slightly or the coating thickness of the first adhesive layer needs to be changed, the first telescopic component 270 shortens, causing the second connecting bracket 260 to drive the first adhesive coating component 240 to move closer to the center, thereby increasing the contact pressure between the working end of the first adhesive coating component 240 and the outer wall of the tube blank, ensuring uniform coating thickness and sufficient adhesion. Conversely, when it is necessary to reduce the coating pressure or adapt to a larger diameter tube blank, the first telescopic component 270 extends, causing the first adhesive coating component 240 to move radially outward, reducing the contact pressure and avoiding excessive extrusion that could lead to adhesive accumulation or scratches on the surface of the tube blank. At the same time, the rotational freedom of the first adhesive coating component 240 relative to the second connecting bracket 260 allows it to adaptively follow the slight eccentricity or ellipticity changes of the outer wall of the tube blank during its forward movement, always maintaining a stable circumferential contact state.

[0066] In this embodiment, through the multi-link adjustment structure formed by the first connecting bracket 250, the second connecting bracket 260, and the first telescopic member 270, the first adhesive applicator 240 obtains controllable radial displacement capability, and this adjustment action occurs entirely on the outer periphery of the first adhesive application space 220, without interfering with the axial movement trajectory of the tube blank. The first rotary drive assembly 230 continuously drives the first gear ring 232 and the first adhesive applicator 240 to rotate around the tube blank axis, while the radial position adjustment is independent of and uncoupled from the rotational motion, thereby simultaneously achieving circumferential uniform coating and dynamic and precise control of radial pressure / thickness in high-speed continuous production.

[0067] In one embodiment, the first telescopic member 270 is a servo electric push rod with position feedback, and is linked with the online detection device for the outer diameter of the tube blank. A closed-loop control system adjusts the radial position of the first adhesive applicator 240 in real time, controlling the coating thickness fluctuation of the first adhesive layer within ±5μm, further improving the uniformity and bonding strength of the interlayer bonding interface. A limit stop or elastic buffer pad is provided at the hinge point between the first connecting bracket 250 and the second connecting bracket 260 to limit the maximum swing angle of the second connecting bracket 260, preventing excessive interference or disengagement of the first adhesive applicator 240 with the tube blank at extreme positions, ensuring the safety and stability of the adjustment process.

[0068] In one embodiment, the first extrusion molding mechanism 100 includes:

[0069] A first extruded part 120 has a first extrusion molding channel 110 formed therein. The two ends of the first extruded part 120 are a feeding end 160 and a pipe extrusion molding end 140, respectively. The end of the first extrusion molding channel 110 located at the feeding end 160 is a blind end. The feeding end 160 has a first feeding channel 130 that communicates with the first extrusion molding channel 110. The first feeding channel 130 is rotatably connected to the first hopper through a pipe. A guide shaft 170 extending in a first direction is formed inside the first extrusion molding channel 110.

[0070] A first mounting base 180 is mounted on the discharge end of the first hopper, and the first mounting base 180 is rotatably engaged with the first extruded part 120; and,

[0071] The first rotary drive 190 is disposed close to the feed end 160. The first rotary drive 190 is coaxially disposed with the first extrusion molding part 120. The first rotary drive 190 can drive the first extrusion molding part 120 to rotate relative to the first mounting base 180 so that the first extrusion molding channel 110 extrudes to form the inner layer of the HBPE pipe.

[0072] Specifically, a first extrusion molding channel 110 is formed axially through the interior of the first extrusion molding part 120. The first extrusion molding channel 110 is used to extrude the plasticized HBPE melt into a continuous inner tube preform. The two ends of the first extrusion molding part 120 along the first direction are a feeding end 160 and a pipe extrusion molding end 140, respectively. The first extrusion molding channel 110 at the end of the feeding end 160 is in a closed state, i.e., a blind end, so that the melt can only flow unidirectionally towards the pipe extrusion molding end 140 axially. A first feeding channel 130 is formed on the side wall of the feeding end 160, which communicates with the first extrusion molding channel 110. The first feeding channel 130 is rotatably connected to the outlet of the first hopper through a dedicated rotary joint pipe, thereby allowing the first extrusion molding part 120 to continuously receive HBPE raw material from the first hopper while rotating, without twisting or leakage. A guide shaft 170 is coaxially arranged inside the first extrusion molding channel 110, extending along the entire length of the first direction. The front end of the guide shaft 170 is fixed at the blind end position, and the rear end extends close to the outlet of the pipe extrusion molding end 140. It is used to provide central support during the melt flow process and guide the inner tube blank to maintain a stable hollow circular cross-sectional shape, avoiding wall thickness eccentricity or ellipticization caused by uneven melt flow or gravity.

[0073] The first mounting base 180 is fixedly installed near the discharge end of the first hopper. Its inner hole is rotatably engaged with the outer cylindrical surface of the feed end 160 of the first extruded molding part 120 through a precision bearing, enabling the first extruded molding part 120 to rotate stably relative to the first mounting base 180 around its own axis, i.e., in the first direction. The first rotary drive 190 is located near the feed end 160 and is typically a servo motor or a variable frequency speed control motor. Its output shaft is coaxially arranged with the first extruded molding part 120 and reliably transmitted through a key connection or a shrink sleeve. When the first rotary drive 190 is energized, its output torque is directly transmitted to the first extruded molding part 120, causing the entire first extruded molding part 120 to rotate uniformly around the first direction.

[0074] In the actual manufacturing process, HBPE granules from the first hopper are plasticized by a screw 540 extruder or a melt pump, and then continuously enter the first feeding channel 130 through a rotary joint pipe. The first rotary drive 190 drives the first extruded molding part 120 to rotate at a set speed. The melt in the first extrusion molding channel 110 is uniformly pushed and flows axially toward the pipe extrusion molding end 140 under the combined action of rotational centrifugal force, the strong shaping of the guide shaft 170, and the shearing action of the channel wall. Finally, it is continuously extruded from the pipe extrusion molding end 140 in a stable circular tube shape to form the inner tube blank. Since the first extruded molding part 120 is rotating, the melt is subjected to continuous circumferential shearing and mixing in the channel, which significantly improves the uniformity of melt flow and reduces the axial velocity gradient difference or local stagnation area that may be caused by static extrusion. As a result, the wall thickness distribution of the inner tube blank is more uniform and the surface finish of the inner and outer surfaces is higher.

[0075] The guide shaft 170 further enhances the support and shaping effect on the hollow cross section of the inner tube blank. Especially in the semi-molten stage when the tube blank has just left the extrusion end and has not yet fully cooled and shaped, it can effectively resist the collapse or deformation of the cross section caused by its own weight or uneven melt shrinkage, ensuring that the inner tube blank maintains accurate roundness and coaxiality when it enters the subsequent first adhesive coating space 220, creating a stable geometric basis for the uniform coating of the first adhesive layer.

[0076] In one embodiment, a detachable sizing sleeve assembly is provided on the outer periphery of the pipe extrusion end 140 of the first extruded part 120. The inner diameter of the sizing sleeve matches the outer diameter of the target inner layer and is equipped with vacuum sizing or internal pressure support to further improve the dimensional accuracy and surface quality of the inner layer tube blank and reduce the radial adjustment range in the subsequent adhesive coating process. The guide shaft 170 adopts a hollow structure and a cooling medium is introduced into the inner cavity. A spiral guide groove or a multi-section diameter-changing section is provided on the outer surface of the shaft to simultaneously achieve forced cooling and surface finishing of the inner wall of the inner layer during the melt flow process. This allows the inner layer tube blank to quickly form a stable internal and external temperature gradient after extrusion, which is beneficial for subsequent high-temperature interface bonding with the barrier layer.

[0077] In one embodiment, the second extrusion molding mechanism 300 includes:

[0078] A third mounting base 320 is connected to a first mounting base 180 via a screw 540; a first extrusion molding channel 110 extends through the third mounting base 320 along a first direction; and...

[0079] The second extruded part 330 is installed on the end of the third mounting base 320 away from the first adhesive coating mechanism 200. A second extruded molding channel 310 is formed inside the second extruded part 330. A second feeding channel is formed inside the second extruded part 330. The second feeding channel is connected to the second hopper through a pipe.

[0080] The second extruded part 330 can be extruded to form a barrier layer on the outer wall of the first adhesive layer that enters the second extrusion molding channel 310.

[0081] Specifically, the third mounting base 320 is axially fixed to the first mounting base 180 via multiple high-strength screws 540, forming a stable overall frame structure. The first extrusion molding channel 110 runs through the central through-hole of the third mounting base 320 along the first direction, i.e., the direction of tube blank advance. This through-hole is strictly coaxial with the first extrusion molding channel 110, and the inner wall of the through-hole is precision machined and equipped with a wear-resistant bushing or guide ring to ensure that the inner tube blank with the first adhesive layer remains axially aligned and without radial offset when passing through the third mounting base 320, and to reduce the risk of surface scratches. The axial length of the third mounting base 320 is typically designed to accommodate the mounting and positioning reference surface of the subsequent second extruded part 330, while reserving radial space for the reasonable arrangement of the second feeding channel.

[0082] The second extruded part 330 is fixedly installed at the end of the third mounting base 320 away from the first adhesive coating mechanism 200, i.e., at the axial rear end face of the third mounting base 320. A second extrusion molding channel 310 is formed axially through the interior of the second extruded part 330. The diameter of this channel is significantly larger than that of the first extrusion molding channel 110, thus creating a sufficient annular gap to accommodate and extrude the barrier layer melt when the billet passes through. A second feeding channel is also formed inside the second extruded part 330. This second feeding channel is typically arranged radially or obliquely, and its outer end is connected to the outlet of the second hopper via a dedicated feeding pipe. A heating and insulation layer is installed inside the pipe to maintain the melt flowability of the barrier layer material. Inside the second extruded part 330, the second feeding channel and the second extrusion molding channel 310 converge near the extrusion end of the pipe, forming a typical annular flow distribution structure, allowing the barrier layer melt from the second hopper to be evenly distributed circumferentially in the annular channel and converge towards the center.

[0083] In the actual manufacturing process, the inner tube blank with the first adhesive layer is continuously fed out from the first adhesive coating mechanism 200 and directly passes through the central through hole of the third mounting base 320 along the axial direction, entering the second extrusion molding channel 310. Since the third mounting base 320 is connected to the rigid screw 540 of the first mounting base 180, the second extrusion molding channel 310 and the first extrusion molding channel 110 maintain a high degree of coaxiality. The inner tube blank does not need additional centering adjustment when entering the second extrusion molding channel 310 and can pass through stably in the center. The barrier layer raw material supplied by the second hopper is extruded by the screw 540 or plasticized by the melt pump, and then continuously enters the annular diversion area inside the second extruded part 330 through the second feeding channel. The barrier layer melt is subjected to shear and pressure in the annular channel, uniformly coating the outer wall surface of the first adhesive layer, and undergoes interfacial diffusion and molecular chain entanglement with the first adhesive layer in a high-temperature molten state, thereby forming a strong metallurgical bonding interface. Finally, the composite tube blank consisting of the inner layer, the first adhesive layer, and the barrier layer is continuously extruded from the outlet of the second extrusion molding channel 310 and enters the subsequent second coating process.

[0084] Because the diameter of the second extrusion channel 310 is larger than that of the first extrusion channel 110, and the second extruded part 330 is directly mounted on the axial rear end of the third mounting base 320, the barrier layer melt can complete the coating action with a smaller radial flow distance and a lower shear heat history during the extrusion coating process, avoiding interface disturbance or thermal degradation caused by the long-distance parallel flow of multiple layers of melt in traditional co-extrusion die heads. At the same time, the first adhesive layer, as a high-temperature active interface layer, plays an adhesive role at the moment of barrier layer coating, enabling a high-strength bond to be established between the two layers before cooling and solidification.

[0085] In one embodiment, the second adhesive application mechanism 400 includes:

[0086] The fourth mounting base 410 is mounted on the side of the third mounting base 320 away from the first adhesive application mechanism 200. The fourth mounting base 410 has a second adhesive application space 420 coaxially arranged with the second extrusion molding channel 310. The fourth mounting base 410 extends in a direction away from the second extrusion molding mechanism 300 and forms a second mounting position. The second adhesive application space 420 passes through the second mounting position along a first direction and extends out of the fourth mounting base 410.

[0087] A second rotary drive assembly 430 is mounted on a fourth mounting base 410; and...

[0088] The second adhesive applicator 440 is mounted on the second rotary drive assembly 430 and is disposed facing the second adhesive application space 420. The second rotary drive assembly 430 can drive the second adhesive applicator 440 to rotate around the second adhesive application space 420 so that the second adhesive applicator 440 coats the second adhesive layer on the outer wall of the barrier layer that passes through the second extrusion molding channel 310 into the second adhesive application space 420.

[0089] Specifically, the fourth mounting base 410 is fixedly installed on the side of the third mounting base 320 away from the first adhesive application mechanism 200, that is, at the axial rear end face of the third mounting base 320. A high-precision locating pin and bolt combination is typically used to achieve a reliable centering connection with the third mounting base 320. The interior of the fourth mounting base 410 forms a second adhesive application space 420 extending axially. This second adhesive application space 420 is strictly coaxial with the second extrusion molding channel 310, and its inner diameter is slightly larger than the outer diameter of the composite tube blank to ensure that the composite tube blank with the barrier layer can pass smoothly without significant friction. The fourth mounting base 410 extends a cylindrical structure rearward in the direction away from the second extrusion molding mechanism 300, that is, along the first direction, forming a second mounting position. The second adhesive application space 420 extends through the second mounting position along the first direction and extends a fourth mounting base 410 for a certain length at its axial outer end face, thereby providing sufficient external operating space for the radial arrangement and rotation of the second adhesive application part 440, while allowing the composite tube blank to enter and stably pass through the second adhesive application space 420 immediately after leaving the second extrusion molding channel 310.

[0090] The second rotary drive assembly 430 is integrally mounted and fixed on the outer periphery of the fourth mounting base 410. Its specific transmission structure can refer to the arrangement of the first rotary drive assembly 230 described above, including components such as the second rotary bearing 431, the second gear ring 432, the second drive motor 433, and the second transmission gear 434. The second rotary bearing 431 is sleeved on the outer cylindrical surface of the second mounting position along the first direction, with its inner ring precisely fitted to the second mounting position, and its outer ring able to rotate stably around the first direction, i.e., the tube blank axis. The second gear ring 432 is fixed to the outer periphery of the second rotary bearing 431, and the second adhesive coating part 440 is mounted on the side of the second gear ring 432 opposite to the fourth mounting base 410, i.e., the axial outer end face. The second drive motor 433 is fixed at a suitable position on the fourth mounting base 410, with its output shaft extending outward along the first direction, and the second transmission gear 434 mounted on the end of the output shaft and forming a stable mesh with the second gear ring 432. When the second drive motor 433 is running, it drives the second gear ring 432 and the second rotary bearing 431 to rotate synchronously around the second adhesive application space 420 through the gear transmission link, thereby driving the second adhesive application part 440 to make continuous circumferential motion around the composite tube blank axis.

[0091] The working end of the second adhesive applicator 440 is positioned towards the center of the second adhesive application space 420. It typically employs an adhesive application wheel, brush, or scraper structure with elastic or self-adhesive bonding capabilities. Its installation position ensures stable contact or a small gap with the outer wall of the composite tube blank (i.e., the outer surface of the barrier layer) during rotation. In actual manufacturing, the composite tube blank (inner layer + first adhesive layer + barrier layer) is continuously extruded from the second extrusion molding channel 310 and immediately enters and passes through the second adhesive application space 420 axially. At this time, the second rotary drive assembly 430 operates at a speed matching the tube blank's forward speed. The second adhesive applicator 440 rotates synchronously around the tube blank axis with the second gear ring 432, and its working end continuously transfers and evenly coats the supplied second adhesive layer material onto the outer wall surface of the barrier layer. Because of the use of spin coating, the second coating part 440 can achieve 360° full circumference coating coverage without dead angles while the tube blank moves forward at a constant speed, avoiding axial streaks, local accumulation or missed coating defects that may be caused by static coating or spraying, thereby ensuring that the second adhesive layer has a uniform thickness and sufficient interface wetting.

[0092] Through the direct rigid connection between the fourth mounting base 410 and the third mounting base 320, the second adhesive application space 420 and the second extrusion molding channel 310 maintain a high degree of coaxiality. The composite tube blank directly enters the second adhesive application process in a high-temperature extrusion state, without the need for intermediate cooling or guiding adjustment, thus achieving in-situ continuous coating of the second adhesive layer. All rotating components of the second rotary drive assembly 430 are arranged on the outer periphery of the second adhesive application space 420, avoiding contamination, scratches, or heat interference that may be caused by the drive components intruding into the tube blank channel. At the same time, the effective isolation of the second rotary bearing 431 ensures that the fourth mounting base 410 and the second adhesive application space 420 remain stationary and geometrically accurate, so that the composite tube blank maintains a stable straight posture and cross-sectional shape when passing through.

[0093] In one embodiment, the second rotation drive assembly 430 includes:

[0094] The second rotary bearing 431 is sleeved on the outer periphery of the second mounting position along the first direction, and the second rotary bearing 431 can rotate around the first direction outside the second adhesive application space 420.

[0095] The second gear ring 432 is mounted on the outer periphery of the second rotary bearing 431. The second gear ring 432 can follow the second rotary bearing 431 to rotate around the first direction outside the second adhesive space 420.

[0096] A second drive motor 433 is mounted on a fourth mounting base 410, and the output end of the second drive motor 433 extends in a first direction away from the fourth mounting base 410; and...

[0097] The second transmission gear 434 is installed at the output end of the second drive motor 433. The second transmission gear 434 meshes with the second gear ring 432. The second drive motor 433 can drive the second coating part 440 to rotate around the second coating space 420 so that the second coating part 440 coats the second adhesive layer on the outer wall of the barrier layer that passes through the second extrusion molding channel 310 and the second coating space 420.

[0098] Specifically, the second rotary bearing 431 is coaxially sleeved on the outer periphery of the second mounting position formed by the fourth mounting seat 410 along the first direction, i.e., the direction of tube blank advance. Its inner ring is fixed to the outer cylindrical surface of the second mounting position with a high-precision interference fit or set screws to ensure that the inner ring of the bearing remains stationary with the fourth mounting seat 410; the outer ring can rotate stably and with low friction around the first direction outside the second adhesive application space 420. The second rotary bearing 431 is usually selected from a combination of large-size angular contact ball bearings or cylindrical roller bearings to simultaneously bear axial and radial loads and maintain coaxiality and rotational stability during long-term high-speed operation.

[0099] The second gear ring 432 is fixedly mounted on the outer ring end face of the second rotary bearing 431, and is typically positioned circumferentially and axially using bolts or keyways. The outer teeth of the second gear ring 432 are fully distributed circumferentially, and their tooth profile can adopt an involute spur tooth or helical tooth structure to ensure smooth transmission and low noise level when meshing with subsequent transmission gears. The second gear ring 432 can rotate synchronously with the outer ring of the second rotary bearing 431 around the first direction, thereby transmitting the rotational motion to the second adhesive-coated part 440 mounted on the side opposite to the fourth mounting base 410.

[0100] The second drive motor 433 is fixedly mounted on a suitable side wall or bracket of the fourth mounting base 410, and its output shaft extends along the first direction away from the fourth mounting base 410, i.e., towards the outside of the second adhesive application space 420. The second transmission gear 434 is mounted on the output shaft end of the second drive motor 433, and is usually fixed by a key connection or a shrink sleeve to ensure high torque transmission without slippage. The second transmission gear 434 and the second gear ring 432 form a stable meshing relationship. When the second drive motor 433 is energized and running, its output torque is transmitted to the second gear ring 432 through the second transmission gear 434, thereby driving the outer ring of the second rotary bearing 431 and the second gear ring 432 to rotate continuously around the central axis of the second adhesive application space 420, i.e., in the first direction.

[0101] In the actual manufacturing process, the composite tube blank with the barrier layer is continuously extruded from the second extrusion molding channel 310 and directly enters and passes through the second adhesive coating space 420 axially. The second drive motor 433 starts operating according to a preset speed curve or a synchronous ratio matching the tube blank's forward speed. Its output shaft drives the second transmission gear 434 to rotate, and the second transmission gear 434 reliably transmits the rotational motion to the second gear ring 432 through tooth surface meshing. The second gear ring 432 drives the outer ring of the second rotary bearing 431 and the second adhesive coating component 440 fixed thereon to rotate continuously circumferentially around the tube blank axis. During the rotation, the working end of the second adhesive coating component 440 maintains a stable contact or slight pressure fit with the outer wall of the composite tube blank, i.e., the surface of the barrier layer, uniformly transferring and coating the second adhesive layer material onto the outer surface of the barrier layer. Since the rotational action occurs entirely on the outer periphery of the second adhesive coating space 420, the drive component does not intrude into the tube blank channel, thus avoiding any mechanical interference or heat accumulation on the surface of the high-temperature composite tube blank.

[0102] The second rotary bearing 431 ensures complete mechanical isolation and motion decoupling between the rotating component and the stationary fourth mounting base 410, keeping the second coating space 420 and its internal composite tube blank channel absolutely stationary and geometrically accurate, preventing radial sway or axial offset of the composite tube blank during passage. The meshing transmission between the second gear ring 432 and the second transmission gear 434 provides high transmission rigidity and torque capacity, enabling the maintenance of stable rotational speed and coating pressure consistency during long-term continuous production, avoiding periodic fluctuations in coating thickness caused by transmission clearance or elastic deformation.

[0103] In one embodiment, a second hinge position is formed on the side of the second gear ring 432 away from the fourth mounting base 410;

[0104] The second adhesive application unit 400 also includes:

[0105] The third connecting bracket 450 is hinged to the second hinge position and extends from the second mounting position in the first direction away from the fourth mounting base 410.

[0106] A fourth connecting bracket 460, one end of which is hinged to the end of the third connecting bracket 450 away from the fourth mounting base 410, and the other end extending toward the second adhesive application space 420; a second adhesive application member 440 is hinged to the end of the fourth connecting bracket 460 away from the third connecting bracket 450, and the second adhesive application member 440 is rotatable relative to the fourth connecting bracket 460; and,

[0107] The second telescopic member 470 has its two ends hinged to the third connecting bracket 450 and the fourth connecting bracket 460, respectively. The second telescopic member 470 can drive the fourth connecting bracket 460 to rotate around the third connecting bracket 450 so that the second adhesive applicator 440 can move closer to or further away from the second adhesive applicator space 420.

[0108] Specifically, the second gear ring 432 has a second hinge position on its axially outer end face opposite to the fourth mounting base 410. This hinge position is typically a plurality of ear plates or bosses evenly distributed circumferentially, each ear plate having a precision hinge hole for hinged engagement with the subsequent connecting bracket. The second hinge position rotates together with the second gear ring 432 and the second rotary bearing 431 around the first direction, thereby transmitting the rotational motion to the entire adhesive application actuator.

[0109] The third connecting bracket 450 is hinged to the second hinge position via a pin or a high-precision hinge pair. The main body of the third connecting bracket 450 extends along the first direction, i.e., the direction of tube blank advance, away from the fourth mounting base 410, exceeding the axial outer end face of the second mounting position by a certain length. The extended section of the third connecting bracket 450 is typically made of lightweight, high-rigidity material, and its axial length is sufficient to provide enough swing space for the subsequent fourth connecting bracket 460 and the second adhesive-coated part 440 during rotation, while ensuring that the overall center of gravity does not generate excessive eccentric disturbance.

[0110] One end of the fourth connecting bracket 460 is connected to the end of the third connecting bracket 450 away from the fourth mounting base 410 via a hinge joint, while the other end extends radially toward the center of the second adhesive application space 420. The second adhesive application component 440 is mounted on this radially extending end of the fourth connecting bracket 460, and achieves relative rotational freedom with the fourth connecting bracket 460 through bearings or pins, so that the working end of the second adhesive application component 440 can automatically adapt to slight angle changes when in contact with the outer wall of the composite tube blank, always maintaining the optimal fit posture.

[0111] The second telescopic member 470 is connected at both ends to the middle region of the third connecting bracket 450 and the appropriate position of the fourth connecting bracket 460 via hinge pairs. The second telescopic member 470 is typically an electric actuator, a pneumatic cylinder, or a servo linear actuator. Its telescopic movement can precisely control the radial swing of the fourth connecting bracket 460 around the hinge point of the third connecting bracket 450, thereby causing the working end of the second adhesive applicator 440 to move radially closer to or away from the central axis of the second adhesive application space 420.

[0112] In the actual manufacturing process, while the second rotary drive assembly 430 drives the second gear ring 432 to rotate continuously, the second telescopic component 470 dynamically expands and contracts according to a preset control strategy or the real-time feedback signal of the tube blank's outer diameter. When the outer diameter of the composite tube blank increases slightly, the second telescopic component 470 shortens, causing the fourth connecting bracket 460 to swing inward around the hinge point of the third connecting bracket 450, and the second adhesive applicator 440 moves radially inward accordingly, maintaining stable contact pressure with the outer wall of the barrier layer. Conversely, when the outer diameter of the tube blank decreases, the second telescopic component 470 extends, pushing the fourth connecting bracket 460 to swing outward, and the second adhesive applicator 440 moves outward accordingly, avoiding excessive compression or loss of contact. The entire adjustment process is completed simultaneously with the high-speed rotation of the second adhesive applicator 440 along the tube blank axis, achieving real-time adaptive matching between the adhesive application pressure and the tube blank's geometric dimensions.

[0113] Since both the third connecting bracket 450 and the fourth connecting bracket 460 rotate together with the second gear ring 432 around the first direction, the extension and retraction of the second telescopic member 470 only changes the radial position without interfering with the circumferential rotation. Under the combined motion of rotation and radial adjustment, the working end of the second adhesive applicator 440 can achieve continuous and uniform pressure coating on the outer surface of the tube blank, maintaining a high degree of consistency in the thickness of the second adhesive layer even if the tube blank has slight ellipticity, local bulges, or axial diameter fluctuations.

[0114] In one embodiment, the third extrusion molding mechanism 500 includes:

[0115] The fifth mounting base 520 is connected to the third mounting base 320 via a screw 540 and forms a clearance gap with the fourth mounting base 410. The first extrusion molding channel 110 passes through the fifth mounting base 520 along the first direction; and,

[0116] The third extrusion molding part 530 is installed on the end of the fifth mounting base 520 away from the second glue coating mechanism 400. A third extrusion molding channel 510 is formed inside the third extrusion molding part 530. A third feeding channel 550 is formed inside the third extrusion molding part 530. The third feeding channel 550 is connected to the first hopper through a pipe.

[0117] The third extruded part 530 can extrude an outer layer onto the outer wall of the second adhesive layer that enters the third extrusion molding channel 510.

[0118] Specifically, the fifth mounting base 520 is axially fixed to the third mounting base 320 via multiple high-strength screws 540, forming a continuous load-bearing structure for the overall frame. Simultaneously, sufficient clearance is maintained axially between the fifth mounting base 520 and the fourth mounting base 410. This clearance accommodates the radially extended portion of the rotating component in the second adhesive application mechanism 400 and provides space for the installation and operation of the second telescopic component 470, preventing interference during operation. The first extrusion molding channel 110 extends through the central through-hole of the fifth mounting base 520 along the first direction, i.e., the direction of tube blank advance. This through-hole is strictly coaxial with the aforementioned first extrusion molding channel 110, second extrusion molding channel 310, and second adhesive application space 420. The inner wall of the through-hole is precision-machined and typically inlaid with wear-resistant, high-temperature-resistant guide bushings or PTFE composite rings to ensure that the composite tube blank with the second adhesive layer maintains axial stability and exhibits no significant radial displacement or surface damage during high-speed passage.

[0119] The third extruded part 530 is fixedly installed at the end of the fifth mounting base 520 away from the second coating mechanism 400, that is, at the axial rear end face of the fifth mounting base 520. A third extrusion molding channel 510 is formed axially through the interior of the third extruded part 530. The diameter of this channel is significantly larger than the outlet diameter of the second coating space 420, thus creating a sufficient annular gap to accommodate and extrude the outer layer melt when the composite tube blank passes through. A third feeding channel 550 is also formed inside the third extruded part 530. This channel is typically arranged radially or obliquely, and its outer end is connected to the outlet of the first hopper via a dedicated feeding pipe. The pipe is equipped with a heating and insulation layer and a temperature sensor throughout to maintain the melt stability and flowability of the outer layer raw material (usually HDPE or modified HDPE). Inside the third extruded part 530, the third feeding channel 550 and the third extrusion molding channel 510 are connected in an annular confluence area near the outlet end, forming a typical annular flow distribution structure, allowing the outer layer melt from the first hopper to be evenly distributed circumferentially and converge towards the center.

[0120] In the actual manufacturing process, the composite tube blank consisting of the inner layer, the first adhesive layer, the barrier layer, and the second adhesive layer is continuously fed out from the second coating space 420 and directly passes through the central through hole of the fifth mounting base 520 along the axial direction, entering the third extrusion molding channel 510. Since the fifth mounting base 520 is rigidly connected to the third mounting base 320 via the screw 540 and maintains a high degree of coaxiality with the aforementioned channels, the composite tube blank can maintain a stable centered state without additional centering or guiding adjustments when entering the third extrusion molding channel 510. The outer layer raw material supplied by the first hopper is fully plasticized by the screw 540 extruder or melt pump and continuously enters the annular distribution zone inside the third extruded part 530 through the third feeding channel 550. The outer layer melt is subjected to shearing, compression, and pressure within the annular channel, uniformly coating the outer surface of the second adhesive layer. Under high-temperature molten conditions, it undergoes sufficient interfacial diffusion, molecular chain penetration, and entanglement with the second adhesive layer, thereby forming a high-strength metallurgical bonding interface. Finally, the complete five-layer anti-collapse HBPE pipe blank is continuously extruded from the outlet of the third extrusion molding channel 510 and enters the subsequent sizing, cooling, and traction processes.

[0121] Due to the rigid connection between the screw 540 of the fifth mounting base 520 and the third mounting base 320, and the clearance reserved between the fifth mounting base 520 and the fourth mounting base 410, the third extrusion molding channel 510 can achieve a tight connection with the aforementioned second adhesive coating space 420. After the second adhesive layer is coated, the composite pipe blank is in a high-temperature active state and enters the outer layer coating process, avoiding interface oxidation, contamination, or adhesion attenuation caused by intermediate cooling and reheating. At the same time, the larger diameter and shorter radial flow path of the third extrusion molding channel 510 allow the outer melt to complete the coating with a lower shear heat history, reducing the possibility of melt thermal degradation and interface disturbance. As a high-temperature active transition layer, the second adhesive layer plays an interfacial bonding role at the moment of outer melt coating, enabling a strong bond to be established between the outer layer and the inner layer-barrier layer composite before cooling and solidification. Based on the same technical concept, in a second aspect, the present invention also proposes a method for manufacturing an anti-collapse HBPE pipe, using the manufacturing apparatus described in the first aspect;

[0122] The manufacturing method includes the following steps:

[0123] S100: The inner layer is continuously formed by extrusion using the first extrusion molding mechanism;

[0124] S200: The first adhesive layer is formed by continuously applying adhesive to the outer wall of the inner layer using the first adhesive application mechanism;

[0125] S300, Continue to use the second extrusion molding mechanism to extrude and form the barrier layer on the outer wall of the first adhesive layer;

[0126] S400: Continue to apply adhesive to the outer wall of the barrier layer using the second adhesive application mechanism to form the second adhesive layer;

[0127] S500, Continue to use the third extrusion molding mechanism to continuously extrude the outer layer on the outer wall of the second adhesive layer to form the HBPE pipe.

[0128] Specifically, the inner layer raw material (usually high-density polyethylene, HDPE, or modified HDPE) is first added to the first hopper, fully plasticized and metered by the first extruder, and then continuously extruded through the first extrusion molding channel to form an inner layer tube blank with a specified wall thickness and outer diameter. When the inner layer tube blank leaves the outlet of the first extrusion molding channel, it is still in a high-temperature molten or semi-molten state, and its outer surface temperature is usually maintained between 180 and 220°C, exhibiting high surface activity.

[0129] Subsequently, the inner tube blank directly enters the first adhesive coating space. The first rotary drive assembly drives the first adhesive coating component to rotate continuously around the tube blank's axis. Its working end maintains stable contact or slight pressure against the outer wall of the inner layer, uniformly transferring and coating the first adhesive layer material (typically modified polyolefin hot melt adhesive or copolymer adhesive resin) onto the outer surface of the inner layer. Because the first adhesive coating component uses a rotary coating method and achieves precise synchronization with the tube blank's forward speed, the coating achieves 360° full coverage circumferentially without dead angles, while maintaining a consistent thickness along the axial direction, avoiding the axial streaks, localized accumulation, or thickness fluctuations that are easily generated by traditional spraying or dipping coating. The first adhesive layer rapidly wets, diffuses, and initially forms an interfacial bond on the high-temperature inner layer surface.

[0130] Following this, the composite tube blank with the first adhesive layer continuously enters the second extrusion molding channel. The second extrusion molding process involves melting and plasticizing the barrier layer material (typically EVOH, PA, PVDC, or their blends) through the second hopper and the second extruder, then uniformly distributing it to the annular confluence area via the second feeding channel, where it moltenly coats the outer wall of the first adhesive layer. Because the first adhesive layer is still in a high-temperature active state, the barrier layer melt undergoes molecular chain penetration, entanglement, and interfacial diffusion with the first adhesive layer upon contact, forming a high-strength metallurgical bonding interface. After the barrier layer extrusion is completed, the outer surface temperature of the composite tube blank typically remains between 170 and 210°C, providing an ideal interfacial temperature window for the subsequent coating of the second adhesive layer.

[0131] The composite tube blank then enters the second adhesive coating space. The second rotary drive assembly drives the second adhesive coating component to rotate at high speed around the tube blank's axis. Simultaneously, the second telescopic component dynamically adjusts the radial position of the second adhesive coating component based on real-time feedback from the tube blank's outer diameter, ensuring that its working end maintains a constant contact pressure with the outer wall of the barrier layer. The second adhesive layer material (which can be the same as the first adhesive layer or an adhesive resin optimized for the barrier layer material) is uniformly and continuously transferred to the outer surface of the barrier layer under the action of rotary coating, forming a second adhesive layer with uniform thickness and sufficient interface activation. Rotary coating combined with radial adaptive adjustment effectively eliminates coating unevenness or localized missed coating defects caused by slight ellipticity or diameter fluctuations in the tube blank, ensuring the consistency of the second adhesive layer's thickness and the integrity of its interface coverage along its entire length and circumference.

[0132] Finally, the four-layer composite pipe blank with the second adhesive layer passes directly through the central through-hole of the fifth mounting base and enters the third extrusion molding channel. The third extrusion molding process melts the outer layer raw material (usually high-strength, environmentally stress-cracking-resistant HDPE or modified HDPE) in the first hopper, then evenly distributes it to the annular distribution zone through the third feeding channel, coating the outer wall of the second adhesive layer in a molten state. The second adhesive layer plays an interfacial bonding role at the instant of coating by the high-temperature outer molten layer, promoting a rapid and strong metallurgical bond between the outer layer and the barrier layer. The final five-layer structure pipe blank is continuously extruded from the outlet of the third extrusion molding channel, and then sequentially undergoes conventional post-processing steps such as vacuum sizing, spray cooling, traction, and cutting to obtain a dimensionally stable, reliably bonded, and collapse-resistant HBPE pipe.

[0133] In one embodiment, the first and second adhesive layers use the same modified polyolefin hot melt adhesive system. During the coating process, the surface temperature of the composite tube blank is monitored using an infrared thermometer to ensure that the interface temperature of each layer is controlled within the optimal activation range of the adhesive resin (e.g., 190±10℃). This further improves the molecular diffusion depth and bonding strength at each interface, and the peel strength can stably reach above 25 N / cm. The second coating component is a roller coated with high-temperature resistant fluororubber. Under the control of the second telescopic component, the contact pressure is precisely maintained within the range of 0.20–0.30 MPa. At the same time, the coating thickness of the second adhesive layer is controlled within 80–120 μm, so that it can fully wet the surface of the barrier layer while avoiding stress concentration or material waste caused by excessive thickness.

[0134] In this embodiment, through a continuous and integrated five-step extrusion-coating-extrusion composite process, this application achieves high-temperature in-situ interfacial metallurgical bonding between the inner layer, the first adhesive layer, the barrier layer, the second adhesive layer, and the outer layer. This avoids the problems of interfacial oxidation, contamination, residual stress accumulation, and bonding attenuation caused by multiple heating and cooling cycles in traditional step-extrusion, cooling, and then bonding or winding composite processes. Based on process continuity, full utilization of the interfacial temperature window, and synchronicity of bonding between layers, this significantly improves the overall interlayer peel strength, radial collapse resistance, and long-term dimensional stability of the multilayer structure. It effectively reduces the failure risk of HBPE high-barrier liner pipes during trenchless repair of oil and gas pipelines due to interlayer weakening, delamination, radial collapse, or lumen blockage, providing a more reliable lining solution for the long-term safe operation of high-pressure, highly corrosive media pipelines.

[0135] Of course, during extrusion molding, the extrusion speed should also be controlled to ensure that the material layers can bond fully under appropriate temperature and pressure conditions. In this embodiment, the extrusion speed is preferably 1-5 meters per minute.

[0136] It can be further clarified that, in this embodiment, the adhesive material is preferably maleic anhydride-grafted polyethylene (PE-g-MAH) or other adhesives with good bonding properties. The amount of adhesive material applied should be controlled within an appropriate range to ensure interlayer bonding strength while avoiding increased costs due to excessive adhesive material. In this embodiment, the preferred amount of adhesive material applied is 10-30 grams per square meter.

[0137] To further clarify, when manufacturing HBPE pipes, the inner and outer layers use 27-30 parts by weight of PN049 high-density polyethylene (HDPE) as the base material, combined with 7-8 parts by weight of linear low-density polyethylene SP988 to compensate for the insufficient environmental cracking resistance of HDPE; 1-2 parts by weight of silicon carbide whiskers are added as a reinforcing material to improve the pipe modulus by utilizing their high strength properties; barrier material is added, with the thickness of the barrier layer controlled at 5%-10%, and 1 part by weight of chlorinated polyethylene is added as a plasticizer to balance barrier properties and flexibility.

[0138] Then add 1-2 parts by weight of antioxidant (such as hindered phenols and thiodipropionate diester mixed in a 1:1 ratio) to prevent thermal oxidation of the raw materials; add 1 part by weight of anti-aging agent (UV absorber UV-531 and light stabilizer 744 mixed in a 1:1 ratio); and add 0.5-1 parts by weight of polyethylene wax as an internal lubricant to ensure uniform mixing of the raw materials.

[0139] Next, the HBPE barrier layer material is placed in a drying hopper for drying to prevent moisture absorption, which could lead to air bubbles and decreased barrier performance during processing. The HDPE substrate and binder need to be filtered to remove impurities and can also be uniformly mixed with additives in a high-speed mixer to ensure raw material purity. The special structure co-extrusion molding uses a multi-layer composite structure to enhance the thickness of the inner layer of the HBPE pipe to resist external pressure; this is a crucial process for preventing collapse.

[0140] A JWS35 / 25 extruder was selected to process the HBPE barrier layer. The output rate was precisely controlled, and the barrel containing the HBPE barrier layer was accurately fixed in the corresponding extrusion channel. The die, mandrel, and other components were modified, and the flow channel structure was optimized to ensure a smooth transition without dead angles, allowing the five layers of material to converge coaxially within the die and preventing barrier layer misalignment. Simultaneously, the alignment of the die and extrusion channel was checked to ensure the barrier layer was positioned precisely in the center of the pipe.

[0141] The molding materials are fed into the corresponding extruders in batches. The HDPE base material is heated to 190-230℃ and melted in the main extruder, while the barrier layer is heated to 220-240℃ and melted in the auxiliary extruder. The binder material is melted simultaneously and then conveyed to the composite die. The five-layer co-extrusion unit is started and test extrusion is performed at low speed. The plasticization state of the material is observed to check for incomplete plasticization or degradation. At the same time, the pipe profile is observed to determine whether the materials of each layer are uniformly fused and whether the approximate position of the barrier layer is significantly deviated.

[0142] Precise cooling and shaping are crucial, as the cooling effect directly impacts the structural stability of the pipe. Uneven cooling can lead to stress concentration and subsequent collapse. Immediately after extrusion, the pipe blank enters a vacuum cooling chamber. Negative pressure forces the blank to adhere tightly to the shaping sleeve, while circulating cooling water at 23-25°C is introduced for 7-10 minutes. A specially designed shaping sleeve ensures complete outer layer formation while preventing inner layer shrinkage and deformation. Traction and cutting utilize a variable frequency traction machine with a uniform traction speed controlled at 1-3 m / min, strictly matched to the extrusion speed. This prevents pipe stretching due to speed mismatch, which could cause barrier layer displacement or uneven thickness. This prevents uneven wall thickness caused by pipe stretching, weakening its anti-collapse capability. Subsequently, a chipless planetary saw is used for fixed-length cutting according to a preset length (e.g., 9 meters or 16 meters). After cutting, the ends are deburred and rounded to prevent stress concentration and breakage.

[0143] Of course, in order to make the inner liner tube made by the present invention have a longer service life, the thickness of the extruded inner layer can be at least twice the thickness of the outer layer during the manufacturing process. This setting not only increases the wear resistance and service life of the inner liner tube, but also makes the isolation layer closer to the outer layer (i.e., the outer wall of the inner liner tube). This avoids the isolation layer of the traditional inner liner tube being close to the inner layer, and the isolation performance of the isolation layer being affected when the inner layer is damaged. This ensures the isolation function of the isolation layer and improves the service life of the inner liner tube.

[0144] The above are merely exemplary embodiments of the present invention and do not limit the scope of the patent of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A method for manufacturing an anti-collapse HBPE pipe, characterized in that, The manufacturing method employs a manufacturing apparatus comprising components coaxially arranged sequentially along a first direction: The first extrusion molding mechanism has a first extrusion molding channel for extruding to form an inner layer, and the first extrusion molding mechanism is connected to the first hopper; A first adhesive coating mechanism is used to coat the outer wall of the inner layer with a first adhesive layer. The first adhesive coating mechanism includes a second mounting base, a first rotary drive assembly, and a first adhesive coating component. The second mounting base is mounted on the side of the first extrusion molding mechanism away from the first hopper. A first adhesive coating space is formed in the second mounting base and is coaxially arranged with the first extrusion molding channel. The first rotary drive assembly is mounted on the second mounting base, and the first adhesive coating component is mounted on the first rotary drive assembly. The first adhesive coating component is disposed facing the first adhesive coating space. The first rotary drive assembly can drive the first adhesive coating component to rotate around the first adhesive coating space so that the first adhesive coating component coats the outer wall of the inner layer that passes through the first extrusion molding channel and the first adhesive coating space with the first adhesive layer. The second extrusion molding mechanism has a second extrusion molding channel for forming a barrier layer, the second extrusion molding mechanism is connected to a second hopper, and the diameter of the second extrusion molding channel is larger than that of the first extrusion molding channel. A second adhesive application mechanism is used to apply a second adhesive layer to the outer wall of the barrier layer; and The third extrusion molding mechanism has a third extrusion molding channel for forming the outer layer. The third extrusion molding mechanism is connected to the first hopper through a pipe. The diameter of the third extrusion molding channel is larger than that of the second extrusion molding channel. The manufacturing method includes the following steps: The inner layer is continuously formed by extrusion using the first extrusion molding mechanism; wherein the inner layer tube blank is still in a high-temperature molten or semi-molten state when it leaves the outlet of the first extrusion molding channel. The first adhesive layer is formed by continuously applying adhesive to the outer wall of the inner layer using the first adhesive coating mechanism; wherein, since the first adhesive layer is still in a high-temperature active state, the barrier layer melt undergoes molecular chain penetration, entanglement and interface diffusion with the first adhesive layer at the moment of contact, forming a high-strength metallurgical bonding interface. The barrier layer is formed by extruding the second extrusion molding mechanism onto the outer wall of the first adhesive layer. Continue applying adhesive to the outer wall of the barrier layer using the second adhesive application mechanism to form the second adhesive layer; The outer layer is continuously extruded on the outer wall of the second adhesive layer using the third extrusion molding mechanism to form the HBPE pipe; wherein, the second adhesive layer plays an interfacial bonding role at the moment of the high-temperature outer layer melt coating, promoting the rapid formation of a strong metallurgical bond between the outer layer and the barrier layer.

2. The manufacturing method of the anti-collapse HBPE pipe as described in claim 1, characterized in that, The second mounting base extends away from the first extrusion molding mechanism and forms a first mounting position, and the first adhesive application space extends through the first mounting position along the first direction and extends out of the second mounting base; The first rotation drive component includes: A first rotary bearing is sleeved on the outer periphery of the first mounting position along the first direction, and the first rotary bearing can rotate around the first direction outside the first adhesive application space. The first gear ring is mounted on the outer periphery of the first rotary bearing. The first gear ring can rotate around the first direction outside the first adhesive application space, following the first rotary bearing. The first adhesive application component is mounted on the side of the first gear ring away from the second mounting base. A first drive motor, mounted on the second mounting base, wherein the output end of the first drive motor extends along the first direction in a direction away from the second mounting base; and... The first transmission gear is installed at the output end of the first drive motor. The first transmission gear meshes with the first gear ring. The first drive motor can drive the first transmission gear to drive the first gear ring to rotate around the first direction through the first rotary bearing, so that the first adhesive application part can rotate around the first adhesive application space and apply adhesive.

3. The manufacturing method of the anti-collapse HBPE pipe as described in claim 2, characterized in that, The first gear ring has a first hinge position on the side opposite to the second mounting base; The first adhesive application mechanism further includes: A first connecting bracket is hinged to the first hinge position, and the first connecting bracket extends out of the first mounting position along a first direction in a direction away from the second mounting base; A second connecting bracket, one end of which is hinged to the end of the first connecting bracket away from the second mounting base, and the other end extending toward the first adhesive application space; the first adhesive application member is hinged to the end of the second connecting bracket away from the first connecting bracket, and the first adhesive application member is rotatable relative to the second connecting bracket; and, The first telescopic member has two ends hinged to the first connecting bracket and the second connecting bracket, respectively. The first telescopic member can drive the second connecting bracket to rotate around the first connecting bracket so that the first adhesive applicator can move closer to or further away from the first adhesive applicator space.

4. The method for manufacturing the anti-collapse HBPE pipe as described in claim 3, characterized in that, The first extrusion molding mechanism includes: A first extruded part, wherein a first extruded channel is formed within the first extruded part, and the two ends of the first extruded part are a feeding end and a pipe extrusion end, respectively. The end of the first extruded channel located at the feeding end is a blind end. The feeding end forms a first feeding channel that communicates with the first extruded channel. The first feeding channel is rotatably connected to the first hopper through a pipe. A guide shaft extending in a first direction is formed within the first extruded channel. A first mounting base is installed at the discharge end of the first hopper, and the first mounting base is rotatably engaged with the first extruded part; and... A first rotary drive is disposed near the feeding end and coaxially with the first extrusion molding part. The first rotary drive can drive the first extrusion molding part to rotate relative to the first mounting base so that the first extrusion molding channel extrudes to form the inner layer of the HBPE pipe.

5. The method for manufacturing the anti-collapse HBPE pipe as described in claim 4, characterized in that, The second extrusion molding mechanism includes: A third mounting base, wherein the third mounting base is connected to the first mounting base via a screw, and the first extrusion molding channel extends through the third mounting base along a first direction; and... The second extruded part is mounted on the third mounting base at the end away from the first coating mechanism. The second extruded part has a second extrusion channel and a second feeding channel. The second feeding channel is connected to the second hopper through a pipe. The second extruded part can be extruded to form the barrier layer on the outer wall of the first adhesive layer that enters the second extrusion molding channel.

6. The method for manufacturing the anti-collapse HBPE pipe as described in claim 5, characterized in that, The second adhesive application mechanism includes: The fourth mounting base is mounted on the side of the third mounting base away from the first adhesive coating mechanism. The fourth mounting base has a second adhesive coating space coaxially arranged with the second extrusion molding channel. The fourth mounting base extends in a direction away from the second extrusion molding mechanism and forms a second mounting position. The second adhesive coating space passes through the second mounting position along the first direction and extends out of the fourth mounting base. A second rotary drive assembly, the second rotary drive assembly being mounted on the fourth mounting base; and... The second adhesive applicator is mounted on the second rotary drive assembly and is disposed facing the second adhesive application space. The second rotary drive assembly can drive the second adhesive applicator to rotate around the second adhesive application space so that the second adhesive applicator coats the second adhesive layer on the outer wall of the barrier layer that passes through the second extrusion molding channel into the second adhesive application space.

7. The method for manufacturing the anti-collapse HBPE pipe as described in claim 6, characterized in that, The second rotation drive assembly includes: The second rotary bearing is sleeved on the outer periphery of the second mounting position along the first direction. Furthermore, the second rotary bearing can rotate around the first direction outside the second adhesive application space; The second gear ring is mounted on the outer periphery of the second rotary bearing and can rotate around the first direction outside the second adhesive application space following the second rotary bearing. A second drive motor, mounted on the fourth mounting base, wherein the output end of the second drive motor extends along the first direction in a direction away from the fourth mounting base; and... The second transmission gear is mounted on the output end of the second drive motor and meshes with the second gear ring. The second drive motor can drive the second coating component to rotate around the second coating space so that the second coating component coats the second adhesive layer on the outer wall of the barrier layer that passes through the second extrusion molding channel into the second coating space.

8. The method for manufacturing the anti-collapse HBPE pipe as described in claim 7, characterized in that, The second gear ring has a second hinge position on the side away from the fourth mounting base; The second adhesive application mechanism also includes: The third connecting bracket is hinged to the second hinge position, and the third connecting bracket extends out of the second mounting position along the first direction in a direction away from the fourth mounting base; A fourth connecting bracket, one end of which is hinged to the end of the third connecting bracket away from the fourth mounting base, and the other end extending toward the second adhesive application space; the second adhesive application member is hinged to the end of the fourth connecting bracket away from the third connecting bracket, and the second adhesive application member is rotatable relative to the fourth connecting bracket; and, The second telescopic member has its two ends hinged to the third connecting bracket and the fourth connecting bracket, respectively. The second telescopic member can drive the fourth connecting bracket to rotate around the third connecting bracket so that the second adhesive applicator can move closer to or further away from the second adhesive application space.

9. The method for manufacturing the anti-collapse HBPE pipe as described in claim 8, characterized in that, The third extrusion molding mechanism includes: The fifth mounting base, which is connected to the third mounting base via a screw and forms a clearance gap with the fourth mounting base, wherein the first extrusion molding channel extends through the fifth mounting base along a first direction; and, The third extruded part is installed on the fifth mounting base at the end away from the second coating mechanism. The third extruded part has a third extrusion molding channel and a third feeding channel. The third feeding channel is connected to the first hopper through a pipe. The third extruded part can extrude the outer layer onto the outer wall of the second adhesive layer that enters the third extrusion molding channel.

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