Polypropylene spiral wound structured wall pipes and their manufacturing process

Abstract

This invention discloses a polypropylene spiral wound structured wall pipe and its manufacturing process, relating to the technical field of polypropylene spiral wound structured wall pipes. The technical solution includes a polypropylene spiral wound pipe comprising a pipe body with end pipes fixedly connected to its left and right ends. The pipe body comprises a rectangular tube blank, formed by thermoplastic winding. Adjacent end pipes are connected by a butt joint tube after thermoplastic bonding. The butt joint tube comprises a steel strip ring, and a second polypropylene outer sheath is fixedly installed on the outer wall of the steel strip ring. This invention involves stamping a steel plate into a thin steel sheet, welding a cross-shaped steel sheet to the inner wall of the thin steel sheet to form a grid-like structure, and then thermoplastically casting polypropylene material onto the thin steel sheet and the inner wall of the cross-shaped steel sheet to form a polypropylene inner sheath. Subsequently, polypropylene is thermoplastically cast onto the outer wall of the thin steel sheet to form a first polypropylene outer sheath.

Description

Technical Field

[0001] This invention relates to the field of polypropylene spiral wound structured wall pipe technology, specifically to polypropylene spiral wound structured wall pipe and its manufacturing process. Background Technology

[0002] Polypropylene spiral wound structured wall pipes are made of polypropylene, a highly crystalline, non-polar thermoplastic resin. In its natural state, polypropylene is milky white and, in thin sections, exhibits a degree of translucency. PE has excellent resistance to most household and industrial chemicals.

[0003] The existing technology has the following shortcomings: Existing polypropylene spiral wound structured wall pipes are generally used as sewer drainage pipes, which need to be buried deep underground. They usually need to bear a large load, which requires high mechanical properties of polypropylene spiral wound structured wall pipes. In use, thermoplastic bonding is usually used to fix two polypropylene spiral wound structured wall pipes to be connected. However, because the rigid material structure of existing polypropylene spiral wound structured wall pipes is relatively simple, it is not conducive to improving the compressive strength and crack resistance of polypropylene spiral wound structured wall pipes. At the same time, the butt joint structure used when butt jointing polypropylene spiral wound structured wall pipes is difficult to construct and is not convenient for quick and firm connection.

[0004] Therefore, it is necessary to invent polypropylene spiral wound structured wall pipes and their production process. Summary of the Invention

[0005] To address this issue, the present invention provides a polypropylene spiral wound structured wall pipe, which is formed by stamping steel plates into thin steel sheets, welding and fixing cross-shaped steel sheets onto the inner wall of the thin steel sheets to form a grid-like structure, and then thermoplastically casting polypropylene material onto the inner wall of the thin steel sheets and cross-shaped steel sheets to form a polypropylene inner sheath, and subsequently thermoplastically casting polypropylene onto the outer wall of the thin steel sheets to form a polypropylene outer sheath, thereby solving the problems in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a polypropylene spiral wound structured wall pipe, comprising a polypropylene spiral wound pipe, wherein the polypropylene spiral wound pipe comprises a pipe body, and end pipes are respectively fixedly connected to the left and right ends of the pipe body. The pipe body comprises a rectangular tube blank, which is formed by thermoplastic winding and fixing. Adjacent end pipes are fixedly connected by thermoplastic joining through a connecting sleeve. The connecting sleeve comprises a steel strip ring, a second polypropylene outer sheath is fixedly installed on the outer wall of the steel strip ring, a second polypropylene inner sheath is fixedly installed on the inner wall of the steel strip ring, a retaining ring is fixedly installed at the center of the second polypropylene inner sheath, a slot 1 is opened on the inner wall of the front end of the second polypropylene inner sheath, and a slot 2 is opened on the inner wall of the rear end of the second polypropylene inner sheath. The slot 1 and slot 2 are respectively fitted to insert two end pipes to be connected. The thermoplastic packs are uniformly fixedly installed on the inner walls of the slot 1 and slot 2. The thermoplastic packs are used to be fixedly connected to the outer wall of the end pipe by thermoplastic joining after ignition.

[0007] Preferably, the outer wall of the polypropylene outer sheath is provided with a pressing groove, the pressing groove is configured as an annular shape, and there are two pressing grooves.

[0008] Preferably, the two pressing grooves are located at the front and rear ends of the polypropylene outer sheath II, respectively. The pressing grooves are used to compress and promote adhesion when thermoplastic connection is made between the thermoplastic package and the end tube.

[0009] Preferably, the rectangular tube blank includes a thin steel sheet, which is configured as a hollow rectangular tube, and a cross-shaped steel sheet is welded to the inner wall of the thin steel sheet.

[0010] Preferably, a hollow grid-like structure is formed between the thin steel sheet and the cross-shaped steel sheet, and the thin steel sheet and the cross-shaped steel sheet work together to improve the strength of the rectangular tube blank structure.

[0011] Preferably, a polypropylene inner sheath is fixedly installed on the inner wall of the thin steel sheet and the cross-shaped steel sheet, and a polypropylene outer sheath is fixedly installed on the outer wall of the cross-shaped steel sheet.

[0012] Preferably, a hollow arc tube is fixedly installed on the outer wall of the polypropylene outer sheath. Two hollow arc tubes are provided, and the two hollow arc tubes are respectively fixedly installed on the top and bottom of the polypropylene outer sheath.

[0013] Preferably, the two hollow circular arc tubes are arranged symmetrically, with one overlapping edge fixedly installed on the left outer wall of the first polypropylene outer sheath and another overlapping edge fixedly installed on the right outer wall of the first polypropylene outer sheath.

[0014] Preferably, the top outer wall of the first overlapping edge is flush with the bottom outer wall of the second overlapping edge, and the adjacent first overlapping edge and second overlapping edge are fixedly connected by thermoplastic bonding.

[0015] Equipment for manufacturing polypropylene spiral wound structured wall pipes includes a feeding hopper, with support legs fixedly installed at the four corners of the bottom of the feeding hopper. Four injection-molded pipes are symmetrically arranged vertically, each rectangular in shape. These four pipes are used to weld together thin steel sheets and cross-shaped steel sheets to form a grid-like structure. Diffuser holes are formed around the outer walls of each injection-molded pipe. A conveying pipe is fixedly installed on the inner wall of the injection-molded pipe, with its right end fixedly connected to the inner wall of the feeding hopper. Support frames are fixedly installed on the inner walls of both sides of the feeding hopper, with circular hollow structures on their inner walls. An auger is rotatably connected between two support frames via bearings. The auger is symmetrically positioned front and rear. The device has two augers, each with a synchronous pulley fixedly installed on the outer wall of its right end. The two synchronous pulleys are connected by a synchronous belt drive. The auger is driven by a servo motor. A rear end cover is fixedly installed on the outer wall of the right end of the feeding hopper. An injection hopper is fixedly installed on the top of the feeding hopper. An insulation tank is fixedly installed on the inner wall of the injection hopper. An electric heating element is fixedly installed on the inner wall of the insulation tank. A top cover is fixedly installed on the top of the injection hopper. A servo motor is fixedly installed at the center of the top of the top cover. A feeding roller is fixedly installed on the outer wall of the output shaft of the servo motor. The feeding roller is used to guide the flowing injection molding material inside the injection hopper into the feeding hopper. A feeding hopper is fixedly installed on the top of the top cover. The feeding hopper is used to add injection molding raw materials into the feeding hopper.

[0016] The manufacturing process of polypropylene spiral wound structured wall pipes, including the specific operating steps, is as follows:

[0017] S1: The steel plate is stamped to form a thin steel sheet. The cross-shaped steel sheet is welded and fixed to the inner wall of the thin steel sheet to form a grid structure. Polypropylene material is thermoplastically cast onto the inner wall of the thin steel sheet and the cross-shaped steel sheet to form a polypropylene inner sheath. Then, polypropylene is thermoplastically cast onto the outer wall of the thin steel sheet to form a polypropylene outer sheath.

[0018] S2: The polypropylene raw material is processed into a hollow arc tube by an extruder. Two hollow arc tubes are fixedly connected to the top and bottom outer walls of the polypropylene outer sheath one by thermoplastic process. Overlap edge one and overlap edge two are processed by an extruder. Overlap edge one and overlap edge two are respectively thermoplastic fixedly connected to the left and right outer walls of the polypropylene outer sheath two to form a rectangular tube blank.

[0019] S3: The outer wall of the steel coil is heated by a flame. The rectangular tube blank prepared in S is wound onto the outer wall of the steel coil. The steel coil is driven to rotate to wind the rectangular tube blank onto the outer wall of the steel coil. Then, the rectangular tube blank is tightly wound so that the adjacent overlapping edge one and overlapping edge two are connected by heat fusion to form the tube body.

[0020] S4: Process the end tubes using an extruder, and then thermoplastically connect the two end tubes to the left and right ends of the tube body respectively;

[0021] S5: A steel strip ring is formed by stamping a steel strip. A polypropylene inner sheath II is formed by thermoplastic casting of polypropylene on the inner wall of the steel strip ring. A polypropylene outer sheath II is formed by thermoplastic casting of polypropylene on the outer wall of the steel strip ring. A slot I is opened at both the front and rear ends of the polypropylene inner sheath II.

[0022] S6: Press grooves are opened at both ends of the polypropylene outer sheath II, and a retaining ring is fixedly installed at the center of the inner wall of the polypropylene inner sheath II. The thermoplastic package is fixedly connected to the inner walls of slot I and slot II by thermoplastic fixation.

[0023] The beneficial effects of this invention are:

[0024] 1. By setting up a docking cylinder, when docking two polypropylene spiral tubes that need to be connected, the thermoplastic bag is heated and melted, and the two end tubes are inserted into slot one and slot two respectively. This makes it easier to fill the gap between the polypropylene spiral tube and the docking cylinder, thus improving the sealing performance when the docking cylinder connects the end tubes.

[0025] 2. By setting a rectangular tube blank and using thin steel sheets and cross-shaped steel sheets inside the rectangular tube blank, the mechanical strength of the rectangular tube blank is effectively improved, and its compressive strength and crack resistance are enhanced.

[0026] 3. By setting overlapping edge one and overlapping edge two to connect in a coordinated manner, and by making overlapping edge one and overlapping edge two staggered at the connection points, the structural strength and smoothness of the connection when the equipment winds and connects the rectangular tube blank are improved. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the main view structure provided by the present invention;

[0028] Figure 2 This is a schematic diagram of the internal structure of the polypropylene spiral wound tube provided by the present invention;

[0029] Figure 3 This is a schematic diagram of the docking cylinder installation structure provided by the present invention;

[0030] Figure 4 This is an exploded structural diagram provided by the present invention;

[0031] Figure 5 This is a schematic diagram of the docking cylinder structure provided by the present invention;

[0032] Figure 6 This is a schematic diagram of the rectangular tube blank structure provided by the present invention;

[0033] Figure 7 A schematic diagram of the rectangular tube blank port structure provided by the present invention;

[0034] Figure 8 This is a schematic diagram of the connection structure of overlapping edge one and overlapping edge two provided by the present invention;

[0035] Figure 9 This is a schematic diagram of the main structure of the device provided by the present invention;

[0036] Figure 10 This is a schematic diagram of the injection molding tube structure provided by the present invention;

[0037] Figure 11 This is a schematic diagram of the rear view structure provided by the present invention;

[0038] Figure 12 This is a schematic diagram of the internal structure of the feeding hopper provided by the present invention;

[0039] Figure 13 This is a schematic diagram of the injection chamber structure provided by the present invention;

[0040] Figure 14 This is a schematic diagram of the extrusion roller structure provided by the present invention.

[0041] In the diagram: 100 polypropylene spiral wound tube, 110 tube body, 120 end tube, 200 rectangular tube blank, 210 thin steel sheet, 220 cross-shaped steel sheet, 230 polypropylene inner sheath, 240 polypropylene outer sheath one, 250 hollow circular arc tube, 260 overlapping edge one, 270 overlapping edge two, 300 butt joint cylinder, 310 steel strip ring, 320 polypropylene outer sheath two, 330 slot one, 340 slot two, pressing. 350, retaining ring 360, thermoplastic bag 370, feeding hopper 400, support leg 410, support frame 420, auger 430, synchronous pulley 440, synchronous belt 450, injection pipe 460, diffuser hole 461, conveying pipe 470, rear end cover 480, injection hopper 500, heat preservation tank 510, heating element 520, top cover 530, servo motor 540, feeding roller 550, feeding hopper 560. Detailed Implementation

[0042] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0043] See attached document Figure 1-8The present invention provides a polypropylene spiral wound structural wall pipe. To achieve the above-mentioned objectives, the present invention provides the following technical solution: a polypropylene spiral wound structural wall pipe, comprising a polypropylene spiral wound pipe 100, the polypropylene spiral wound pipe 100 comprising a pipe body 110, end pipes 120 respectively fixedly connected to the left and right ends of the pipe body 110, the pipe body 110 comprising a rectangular tube blank 200, the pipe body 110 being formed by thermoplastic winding and fixed connection of the rectangular tube blank 200, and two adjacent end pipes 120 being fixedly connected by thermoplastic joining through a joining cylinder 300, the joining cylinder 300 comprising a steel strip ring 310. A polypropylene outer sheath 320 is fixedly installed on the outer wall of the 310. A polypropylene inner sheath 320 is fixedly installed on the inner wall of the steel belt ring 310. A retaining ring 360 is fixedly installed at the center of the polypropylene inner sheath 320. A slot 330 is opened on the inner wall of the front end of the polypropylene inner sheath 320, and a slot 340 is opened on the inner wall of the rear end of the polypropylene inner sheath 320. The slots 330 and 340 are respectively inserted into the two end tubes 120 to be connected. A thermoplastic pack 370 is evenly fixedly installed on the inner wall of the slots 330 and 340. The thermoplastic pack 370 is used to connect with the outer wall of the end tube 120 through thermoplastic bonding after ignition. The fixed connection, specifically, involves setting a rectangular tube blank 200, which is wound around the outer wall of a steel pipe. The overlapping edges 260 and 270 at the connection points of the wound rectangular tube blank 200 are thermoplastically connected using polypropylene material after heating. This allows the wound polypropylene spiral pipe 100 to form a polypropylene spiral wound structure pipe. The connecting sleeve 300 facilitates a sealing connection between two polypropylene spiral pipes 100, forming an integrated structure. The steel strip ring 310 is made of steel. The structure facilitates the improvement of the mechanical properties and structural strength of the docking cylinder 300. The end tube 120 facilitates the connection of the docking cylinder 300. The thermoplastic package 370 is made of polypropylene. By setting the thermoplastic package 370, it is convenient to heat the thermoplastic package 370 so that it forms a fluid and fills the gap when the end tube 120 is connected to the slot 1 330 and slot 2 340. This improves the structural strength of the docking cylinder 300 when connected to the end tube 120 and reduces the leakage between the end tube 120 and the docking cylinder 300.

[0044] The outer wall of the polypropylene outer sheath 320 has a pressing groove 350, which is annular. There are two pressing grooves 350, located at the front and rear ends of the polypropylene outer sheath 320 respectively. The pressing grooves 350 are used to compress and promote adhesion when thermoplastically connecting the thermoplastic package 370 and the end tube 120. The rectangular tube blank 200 includes a thin steel sheet 210, which is a hollow rectangular tube. A cross-shaped steel sheet 220 is welded to the inner wall of the thin steel sheet 210. The thin steel sheet 210 and the cross-shaped steel sheet 220 form a hollow grid structure. The thin steel sheet 210 and the cross-shaped steel sheet 220 work together to improve the rectangular tube shape. The tube blank 200 has structural strength. A polypropylene inner sheath 230 is fixedly installed on the inner wall of the thin steel sheet 210 and the cross-shaped steel sheet 220, and a polypropylene outer sheath 240 is fixedly installed on the outer wall of the cross-shaped steel sheet 220. Specifically, by setting a pressing groove 350, pressure is applied to the outer wall of the pressing groove 350 by an extrusion device when thermoplastic connecting the connecting cylinder 300 and the end tube 120, thereby improving the tightness of the connection at the joint of the slot 1 330, slot 2 340 and the outer wall of the end tube 120. The use of the thin steel sheet 210 and the cross-shaped steel sheet 220 in combination can conveniently improve the internal mechanical strength of the rectangular tube blank 200.

[0045] Hollow arc tubes 250 are fixedly installed on the outer wall of the polypropylene outer sheath 240. Two hollow arc tubes 250 are provided, fixedly installed at the top and bottom of the polypropylene outer sheath 240 respectively, symmetrically arranged vertically. Overlap edge 260 is fixedly installed on the left outer wall of the polypropylene outer sheath 240, and overlap edge 270 is fixedly installed on the right outer wall. The top outer wall of overlap edge 260 overlaps with overlap edge 270. The bottom outer wall is flush with the surface, and adjacent overlapping edges 260 and 270 are fixedly connected by thermoplastic bonding. Specifically, by setting hollow arc tubes 250, the compressive strength and crack resistance of the outer wall of the polypropylene spiral wound pipe 100 are improved, thereby increasing the service life of the polypropylene spiral wound pipe 100. At the same time, the hollow arc tubes 250 also provide heat insulation and heat preservation properties. By setting two hollow arc tubes 250 symmetrically, one above the other, it is convenient to control the internal structure of the polypropylene spiral wound pipe 100. Both the inner and outer walls provide protection, improving the practicality, usability, and lifespan of the equipment. By using overlapping edges 260 and 270 together, during the processing of rectangular tube blanks 200 to form the polypropylene spiral wound tube 100, adjacent overlapping edges 260 and 270 can be stably joined. The connection between overlapping edges 260 and 270 is fixed using thermoplastic bonding, thus improving the equipment's practicality and resistance to pressure, cracking, and aging. By ensuring the top outer wall of overlapping edge 260 is flush with the bottom outer wall of overlapping edge 270, the interface remains flush when overlapping edges 260 and 270 are joined after winding, improving the smoothness of the winding connection of the rectangular tube blank 200 and enhancing the structural stability of the connection between overlapping edges 260 and 270, preventing interference between them.

[0046] The equipment used for preparing polypropylene spiral wound structured wall pipes includes a feeding hopper 400, with support legs 410 fixedly installed at the four corners of the bottom of the feeding hopper 400. An injection molding pipe 460 is fixedly installed at the output end of the feeding hopper 400. Four injection molding pipes 460 are symmetrically arranged vertically. The four injection molding pipes 460 are rectangular and are used to form a grid-like structure by welding thin steel sheets 210 and cross-shaped steel sheets 220 together. Diffuser holes 461 are formed around the outer wall of each injection molding pipe 460. A conveying pipe 470 is fixedly installed on the inner wall of the injection molding pipe 460. The right end of the conveying pipe 470 is fixedly connected to the inner wall of the feeding hopper 400. The inner walls of the left and right sides of the feeding hopper 400 are also connected. Each support frame 420 is fixedly installed. The inner wall of the support frame 420 is designed with a circular hollow structure. The two support frames 420 are rotatably connected to the auger 430 via bearings. There are two augers 430 symmetrically arranged front and rear. The outer wall of the right end of each auger 430 is fixedly installed with a synchronous pulley 440. The two synchronous pulleys 440 are connected by a synchronous belt 450. The auger 430 is driven by a servo motor. The outer wall of the right end of the feeding bin 400 is fixedly installed with a rear end cover 480. The top of the feeding bin 400 is fixedly installed with an injection molding bin 500. The inner wall of the injection molding bin 500 is fixedly installed with an insulation tank 510. The inner wall of the insulation tank 510 is fixedly installed with an electric heating element 520. The injection molding bin 500... A top cover 530 is fixedly installed at the top. A servo motor 540 is fixedly installed at the center of the top of the top of the top cover 530. A feeding roller 550 is fixedly installed on the outer wall of the output shaft of the servo motor 540. The feeding roller 550 is used to guide the flowing injection molding material inside the injection hopper 500 into the feeding hopper 400. A feeding hopper 560 is fixedly installed on the top of the top cover 530. The feeding hopper 560 is used to add injection molding raw materials into the feeding hopper 400. Specifically, the feeding hopper 400 is configured to guide the injection molding raw materials into the injection tubes 460. A grid-shaped structure formed by welding thin steel sheets 210 and cross-shaped steel sheets 220 is fitted onto the outer wall of the four injection tubes 460. The injection molding material is introduced into the injection chamber 500 through the feeding hopper 560 and heated to a fluid state by the heating element 520. Then, the servo motor 540 drives the feeding roller 550 to rotate, so that the injection molding material is introduced into the feeding chamber 400 through the feeding roller 550. Then, the two screw conveyors 430 are driven to rotate synchronously to squeeze the injection molding material into the conveying pipe 470. The material inside the conveying pipe 470 is evenly diffused through the diffusion hole 461 onto the outer wall of the grid-shaped structure formed by welding the thin steel sheet 210 and the cross-shaped steel sheet 220 to form the ethylene outer sheath 240.

[0047] The manufacturing process of polypropylene spiral wound structured wall pipes, including the specific operating steps, is as follows:

[0048] S1: A steel plate is stamped to form a thin steel sheet 210. A cross-shaped steel sheet 220 is welded and fixed to the inner wall of the thin steel sheet 210 to form a grid structure. Polypropylene material is thermoplastically cast onto the inner wall of the thin steel sheet 210 and the cross-shaped steel sheet 220 to form a polypropylene inner sheath 230. Subsequently, polypropylene is thermoplastically cast onto the outer wall of the thin steel sheet 210 to form a polypropylene outer sheath 240.

[0049] S2: The polypropylene raw material is processed into a hollow circular arc tube 250 by an extruder. Two hollow circular arc tubes 250 are fixedly connected to the top and bottom outer walls of the polypropylene outer sheath 240 by thermoplastic forming. The overlapping edge 260 and overlapping edge 270 are processed by an extruder. The overlapping edge 260 and overlapping edge 270 are respectively thermoplastic fixedly connected to the left and right outer walls of the polypropylene outer sheath 320 to form a rectangular tube blank 200.

[0050] S3: The outer wall of the steel coil is heated by a flame. The rectangular tube blank 200 prepared in S2 is wound onto the outer wall of the steel coil. The steel coil is driven to rotate to wind the rectangular tube blank 200 onto the outer wall of the steel coil. Then, the rectangular tube blank 200 is tightly wound so that the adjacent overlapping edge 1 260 and overlapping edge 270 are connected by heat fusion to form the tube body 110.

[0051] S4: Process the end tubes 120 using an extruder, and then thermoplastically connect the two end tubes 120 to the left and right ends of the tube body 110 respectively.

[0052] S5: A steel strip ring 310 is formed by stamping a steel strip. A polypropylene inner sheath II is formed by thermoplastic casting of polypropylene on the inner wall of the steel strip ring 310. A polypropylene outer sheath II 320 is formed by thermoplastic casting of polypropylene on the outer wall of the steel strip ring 310. A slot I 330 is opened at both the front and rear ends of the polypropylene inner sheath II.

[0053] S6: Pressing grooves 350 are opened at both ends of the polypropylene outer sheath 320. A retaining ring 360 is fixedly installed at the center of the inner wall of the polypropylene inner sheath 320. A thermoplastic package 370 is fixedly connected to the inner wall of slot 1 330 and slot 2 340 by thermoplastic fixation.

[0054] The above are merely preferred embodiments of the present invention. Any person skilled in the art may modify the present invention or modify it into an equivalent technical solution using the technical solutions described above. Therefore, any simple modifications or equivalent substitutions made based on the technical solutions of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A polypropylene spiral wound structure wall pipe, comprising a polypropylene spiral wound pipe (100), wherein the polypropylene spiral wound pipe (100) comprises a pipe body (110), and end pipes (120) are fixedly connected to the left and right ends of the pipe body (110), the pipe body (110) comprises a rectangular tube blank (200), the pipe body (110) is formed by thermoplastic winding and fixed connection of the rectangular tube blank (200), and two adjacent end pipes (120) are fixedly connected by thermoplastic welding through a butt joint cylinder (300), the butt joint cylinder (300) comprises a steel strip ring (310), and a polypropylene outer sheath two (320) is fixedly installed on the outer wall of the steel strip ring (310). A polypropylene inner sheath two is fixedly installed on the inner wall of the steel belt ring (310). A retaining ring (360) is fixedly installed at the center of the polypropylene inner sheath two. A slot one (330) is opened on the inner wall of the front end of the polypropylene inner sheath two, and a slot two (340) is opened on the inner wall of the rear end of the polypropylene inner sheath two. The slot one (330) and the slot two (340) are respectively fitted to two end tubes (120) to be connected. A thermoplastic bag (370) is evenly fixedly installed on the inner wall of the slot one (330) and the slot two (340). The thermoplastic bag (370) is used to fix the end tube (120) to the outer wall of the end tube (120) by thermoplastic form after ignition; the feature is: The rectangular tube blank (200) includes a thin steel sheet (210), which is configured as a hollow rectangular tube. A cross-shaped steel sheet (220) is welded to the inner wall of the thin steel sheet (210), forming a hollow grid structure between the thin steel sheet (210) and the cross-shaped steel sheet (220). The thin steel sheet (210) and the cross-shaped steel sheet (220) work together to improve the structural strength of the rectangular tube blank (200). A polypropylene inner sheath (230) is fixedly installed on the inner wall of the thin steel sheet (210) and the cross-shaped steel sheet (220), and a polypropylene outer sheath (240) is fixedly installed on the outer wall of the cross-shaped steel sheet (220). The polypropylene outer sheath (240) is externally... Hollow arc tubes (250) are fixedly installed on the wall. There are two hollow arc tubes (250). The two hollow arc tubes (250) are fixedly installed on the top and bottom of the polypropylene outer sheath (240) respectively. The two hollow arc tubes (250) are symmetrically arranged vertically. The first overlapping edge (260) is fixedly installed on the left outer wall of the first polypropylene outer sheath (240). The second overlapping edge (270) is fixedly installed on the right outer wall of the first polypropylene outer sheath (240). The top outer wall of the first overlapping edge (260) and the bottom outer wall of the second overlapping edge (270) are flush. The adjacent first overlapping edge (260) and second overlapping edge (270) are fixedly connected by thermoplastic fixation.

2. The polypropylene spiral wound structured wall pipe according to claim 1, characterized in that, The outer wall of the polypropylene outer sheath (320) is provided with a pressing groove (350), the pressing groove (350) is set in a ring shape, and there are two pressing grooves (350).

3. The polypropylene spiral wound structured wall pipe according to claim 2, characterized in that, The two compression grooves (350) are located at the front and rear ends of the polypropylene outer sheath (320), respectively. The compression grooves (350) are used to compress and promote adhesion when thermoplastic connection is made between thermoplastic package (370) and end tube (120).

4. The equipment used to prepare the polypropylene spiral wound structured wall pipe according to any one of claims 1-3, characterized in that, The system includes a feeding hopper (400), with support legs (410) fixedly installed at the four corners of the bottom of the feeding hopper (400). An injection molding tube (460) is fixedly installed at the output end of the feeding hopper (400). Four injection molding tubes (460) are symmetrically arranged vertically. The four injection molding tubes (460) are rectangular and are used to connect thin steel sheets (210) and cross-shaped steel sheets (220) to form a grid-like structure. Diffuser holes are provided around the outer walls of each injection molding tube (460). 461), a material conveying pipe (470) is fixedly installed on the inner wall of the injection molding pipe (460). The right end of the material conveying pipe (470) is fixedly connected to the inner wall of the feeding bin (400). Support frames (420) are fixedly installed on the inner walls of both the left and right sides of the feeding bin (400). The inner wall of the support frame (420) is set as a circular hollow structure. The two support frames (420) are rotatably connected to the auger (430) through bearings. There are two augers (430) arranged symmetrically in front and behind. The outer wall of the right end of the auger (430) All are fixedly installed with synchronous pulleys (440), and the two synchronous pulleys (440) are connected by a synchronous belt (450). The auger (430) is driven by a servo motor. The outer wall of the right end of the feeding bin (400) is fixedly installed with a rear end cover (480). The top of the feeding bin (400) is fixedly installed with an injection molding bin (500). The inner wall of the injection molding bin (500) is fixedly installed with an insulation tank (510). The inner wall of the insulation tank (510) is fixedly installed with an electric heating element (520). The injection molding bin (510) is fixedly installed with a synchronous belt (450). 00) A top cover (530) is fixedly installed on the top. A servo motor (540) is fixedly installed at the center of the top of the top cover (530). A feeding roller (550) is fixedly installed on the outer wall of the output shaft of the servo motor (540). The feeding roller (550) is used to guide the flowing injection molding material inside the injection chamber (500) into the feeding chamber (400). A feeding hopper (560) is fixedly installed on the top of the top cover (530). The feeding hopper (560) is used to add injection molding raw materials inside the feeding chamber (400).

5. The production process using the equipment for polypropylene spiral wound structured wall pipes as described in claim 4, characterized in that, The specific operating steps are as follows: S1: A steel plate is stamped to form a thin steel sheet (210). A cross-shaped steel sheet (220) is welded and fixed to the inner wall of the thin steel sheet (210) to form a grid structure. Polypropylene material is thermoplastically cast onto the inner wall of the thin steel sheet (210) and the cross-shaped steel sheet (220) to form a polypropylene inner sheath (230). Then, polypropylene is thermoplastically cast onto the outer wall of the thin steel sheet (210) to form a polypropylene outer sheath (240). S2: The polypropylene raw material is processed by an extruder to form a hollow circular arc tube (250). Two hollow circular arc tubes (250) are fixedly connected to the top and bottom outer walls of the polypropylene outer sheath one (240) by thermoplastic forming. The overlapping edge one (260) and overlapping edge two (270) are processed by an extruder. The overlapping edge one (260) and overlapping edge two (270) are respectively thermoplastic fixedly connected to the left and right outer walls of the polypropylene outer sheath two (320) to form a rectangular tube blank (200). S3: The outer wall of the steel coil is heated by a flame. The rectangular tube blank (200) prepared in S2 is wound onto the outer wall of the steel coil. The rectangular tube blank (200) is wound onto the outer wall of the steel coil by driving the steel coil to rotate. Then, the rectangular tube blank (200) is tightly wound so that the adjacent overlapping edge one (260) and overlapping edge two (270) are connected by heat fusion to form the tube body (110). S4: Process the end tubes (120) using an extruder, and then thermoplastically connect the two end tubes (120) to the left and right ends of the tube body (110) respectively; S5: A steel strip ring (310) is formed by stamping the steel strip. A polypropylene inner sheath II is formed by thermoplastic casting of polypropylene on the inner wall of the steel strip ring (310). A polypropylene outer sheath II (320) is formed by thermoplastic casting of polypropylene on the outer wall of the steel strip ring (310). A slot I (330) is opened at both ends of the polypropylene inner sheath II. S6: Press grooves (350) are opened at both ends of the polypropylene outer sheath (320), and a retaining ring (360) is fixedly installed at the center of the inner wall of the polypropylene inner sheath (320). A thermoplastic package (370) is fixedly connected to the inner wall of slot one (330) and slot two (340) by thermoplastic fixation.

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