A method and system for preparing a PE composite pipe

Abstract

The application provides a PE composite pipe preparation method and preparation system, relates to the technical field of PE composite pipe production, and comprises the following steps: S1, mixing raw materials of high-density polyethylene and medium-density polyethylene according to a specific ratio to obtain outer layer mixed material and inner layer mixed material; S2, screening the outer layer mixed material and the inner layer mixed material after grinding them into granular shapes to obtain outer layer extrusion raw material and inner layer extrusion raw material; S3, adding the outer layer extrusion raw material and the inner layer extrusion raw material into an extruder to perform extrusion to obtain an outer layer PE film and an inner layer PE film; S4, using barrier glue to composite the outer layer PE film and the inner layer PE film to form a composite PE film; and S5, trimming the composite PE film, then overlapping and cooling and shaping the composite PE film to obtain the PE composite pipe. The extrusion raw material is screened and then extruded, so that the texture of the outer layer PE film and the inner layer PE film is uniform and flat, the flatness of the composite PE film is improved, and the quality of the PE composite pipe is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PE composite pipe production, and in particular to a PE composite pipe preparation method and preparation system. Background Art

[0002] PE refers to polyethylene material, which is the simplest macromolecular organic compound. PE plastic composite pipe refers to a composite of multiple layers of materials, in which PE material is the main component. It is widely used and has excellent resistance to most domestic and industrial chemicals.

[0003] In the existing PE composite pipe production process, although all raw materials are ground before being added to the extruder, they are not screened after grinding. A small amount of unground raw materials will be added to the extruder. The oversized raw materials will not melt completely in the extruder, resulting in uneven surface texture and defects in the produced PE composite pipe. Summary of the Invention

[0004] The present invention provides a PE composite pipe preparation method and preparation system, which are used to solve the technical problem in the prior art that the raw materials have large size differences, resulting in incomplete melting of a small amount of raw materials, resulting in uneven surface texture and defects in the produced PE composite pipe.

[0005] In one aspect, the present invention provides a method for preparing a PE composite pipe, comprising:

[0006] Step S1, mixing high-density polyethylene and medium-density polyethylene in a specific ratio to obtain an outer layer mixture and an inner layer mixture respectively;

[0007] Step S2, grinding the outer layer mixture and the inner layer mixture into granules respectively and then sieving them to obtain the outer layer extrusion raw material and the inner layer extrusion raw material;

[0008] Step S3, adding the outer layer extrusion raw material and the inner layer extrusion raw material into the extruder respectively for extrusion to obtain the outer layer PE film and the inner layer PE film;

[0009] Step S4, using barrier glue to compound the outer PE film and the inner PE film to form a composite PE film;

[0010] Step S5: trimming the composite PE film, overlapping it, cooling it and shaping it to obtain a PE composite pipe.

[0011] Preferably, the raw materials of the inner layer mixture include, by weight: 80 parts of medium-density polyethylene, 6 parts of ceramic particles, 3 parts of lubricant, 2 parts of rare earth porcelain sand and 9 parts of polyolefin fiber fabric; the raw materials of the outer layer mixture include, by weight: 85 parts of high-density polyethylene, 5 parts of anti-ultraviolet agent, 8 parts of antioxidant and 2 parts of masterbatch.

[0012] A PE composite pipe preparation system is used to prepare PE composite pipes using the above-mentioned PE composite pipe preparation method. It is characterized by comprising two sets of base film manufacturing devices, a dry-type composite machine, a processing and detection device, and a pipe forming device. The two sets of base film manufacturing devices are respectively used to manufacture an outer PE film and an inner PE film. The dry-type composite machine is used to composite the outer PE film and the inner PE film. The processing and detection device is used to trim and detect the composite PE film. The pipe forming device is used to overlap, cool and shape the composite PE film.

[0013] Preferably, the processing and detection device includes a workbench, a waste box is provided inside the workbench, a material trough is provided on the upper surface of the workbench, waste openings are provided on the front and rear sides of the material trough and are connected to the waste box, a mounting frame 1 and a mounting frame 2 are fixedly connected to the upper surface of the workbench, a camera is installed on the inner top surface of the mounting frame 2, the camera is used to take real-time images of the composite PE film, an electric telescopic rod 2 is fixedly connected to the inner top surface of the mounting frame 1, the telescopic end of the electric telescopic rod 2 is fixedly connected to the mounting plate, two groups of cutting components are symmetrically provided on the left and right surface of the lower surface of the mounting plate, the cutting component includes a sliding groove, the sliding groove is provided on the lower surface of the mounting plate, a center rod is fixedly connected in the sliding groove, a sliding block is slidably connected to the left and right direction on the center rod, and a cutting knife is fixedly connected to the lower surface of the sliding block.

[0014] Preferably, the tube forming device includes a chassis, a third motor is installed in the chassis, the output end of the third motor is fixedly connected to gear one, gear one is meshed with a gear two and three gear threes, gear two is located above gear one, gear two is fixedly connected to rotating shaft one, the three gear threes are respectively located on the left, right and bottom sides of gear one, each gear three is fixedly connected to a rotating shaft two, the three rotating shafts two are respectively provided with limit blocks at different positions, the rotating shaft one and the rotating shaft two rotate through the outer wall of the chassis, an extrusion wheel is provided above the rotating shaft one, the extrusion wheel is fixedly connected to gear four by a connecting rod, gear four is meshed with gear two, a support platform is fixedly connected to the chassis, and a flame spray gun is installed on the support platform.

[0015] Preferably, the base film manufacturing device includes a raw material processing device, a screw extruder and a vertical traction machine. The raw material processing device is used to crush the raw materials. The discharge port of the raw material processing device is connected to the feed port of the screw extruder through a feed pipe. The vertical traction machine is arranged on the discharge port side of the screw extruder. The screw extruder is used to pull the material strip extruded by the screw extruder.

[0016] Preferably, the raw material processing device includes a shell, a working chamber and an installation chamber are provided inside the shell, the working chamber is divided into an upper chamber and a lower chamber by a partition, a drop-out port is provided on the partition, a crushing assembly is provided in the upper chamber, a sieve plate is rotatably connected to the left side wall of the lower chamber, a mounting platform is fixedly connected to the right side wall of the lower chamber, an electric telescopic rod 1 is installed on the upper surface of the mounting platform, the telescopic end of the electric telescopic rod 1 is hinged to the lower surface of the sieve plate, a screw conveyor is installed in the installation chamber, the feed end of the screw conveyor is connected to the lower chamber, and the discharge end of the screw conveyor is connected to the upper chamber, a mixing trough is fixedly connected to the outer wall of the shell, the discharge port of the mixing trough is connected to the upper chamber through a connecting pipe 1, and a mixing assembly is provided in the mixing trough.

[0017] Preferably, the raw material processing device also includes a first motor, which is fixedly connected to the upper surface of the shell, and the output end of the first motor is fixedly connected to a turntable, a convex block is provided on the lower surface of the turntable, and the upper wall of the shell is slidably connected to a control plate along the up and down directions, the control plate passes through a connecting pipe, and a material passing hole is provided on the control plate, and the upper end of the control plate is fixedly connected to a top plate, and a spring is fixedly connected between a lower surface of the top plate and the upper surface of the shell.

[0018] Preferably, the crushing assembly includes a lifting rod, the upper end of the lifting rod is fixedly connected to a top plate 2, a spring 2 is fixedly connected between the lower surface of the top plate 2 and the upper surface of the outer shell, the lower end of the lifting rod is fixedly connected to a blocking block, the upper end of the blocking block is provided with a conical surface, the lifting rod is fixedly connected to a drive box, the outer side of the lifting rod is rotatably sleeved with a crushing roller, the crushing roller is driven to rotate by a rotating drive device, and the rotating drive device is provided in the drive box.

[0019] Preferably, a temperature monitoring module is provided in the screw extruder, and the temperature monitoring module includes:

[0020] Several thermocouples are installed inside the screw extruder to detect the melt temperature at various locations of the screw extruder;

[0021] Temperature calculation unit, used to calculate theoretical extrusion temperature;

[0022]

[0023] Among them, T j is the theoretical extrusion temperature; T w is the melting temperature of the melt; σ1 and σ2 are the influence coefficients of mold length and mold cross-sectional area respectively; L0 is the preset reference mold length; L is the actual mold length; H is the actual mold height; D is the actual mold width; H0 is the preset reference mold height; D0 is the preset reference mold width; q is the heat flux density per unit area between the melt and the inner surface of the mold; t n is the preset maximum allowable solidification time; C is the specific heat capacity of the melt; V pis the preset reference extrusion speed; t0 is the unit time length; ρ w is the density of the melt; V S is the actual extrusion speed of the melt; μ s is the dynamic viscosity of the melt; ρ p is the reference value of the preset melt density; μ p It is the reference value of the preset melt dynamic viscosity;

[0024] The temperature judgment unit calculates the difference between the actual extrusion temperature measured by the thermocouple and the theoretical extrusion temperature. When the difference is greater than the preset danger threshold, an alarm is issued;

[0025] The temperature control unit is used to adjust the temperature of the last heating section of the screw extruder to the target adjustment temperature when the temperature judgment unit alarms;

[0026] A regulating temperature calculation unit, used to calculate the target regulating temperature of the last heating section;

[0027]

[0028] Among them, T a Target temperature adjustment for the last heating section of the screw extruder; L j is the length of the last heating section of the screw extruder; π is the circumference of the circle; d is the inner diameter of the heating section; N is the screw speed; p is the screw pitch; t0 is the unit time length; h is the convective heat transfer coefficient of the melt; C is the specific heat capacity of the melt; ρ w is the density of the melt; V S is the actual extrusion speed of the melt; T j is the theoretical extrusion temperature; T r It is the temperature of the melt when it enters the last heating section.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] By grinding the outer layer mixture and the inner layer mixture into granules before extrusion, the size of the raw materials is reduced and the melting time of the raw materials is shortened. By screening the ground raw materials, it is prevented that oversized raw materials enter the extruder and are not completely melted, which affects the quality of the PE composite pipe. The PE pipe is prepared by compounding the outer PE film and the inner PE film, which can make the inner and outer layers of the PE pipe have different characteristics, thereby improving the quality of the PE pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 Schematic diagram of the structure of a PE composite pipe preparation system provided by an embodiment of the present invention;

[0033] Figure 2 It is a left-side structural schematic diagram of the processing and detection device of the present invention;

[0034] Figure 3 2. It is a schematic diagram of the structure of the tube forming device of the present invention from the left side;

[0035] Figure 4 It is a schematic diagram of the main structure of the raw material processing device of the present invention;

[0036] Figure 5 yes Figure 4 Enlarged view of point A in the middle.

[0037] Reference numerals:

[0038] 1. Dry laminating machine; 2. Processing and detection device; 3. Tube forming device; 4. Raw material processing device; 5. Screw extruder; 6. Vertical haul-off machine; 7. Feed pipe; 8. Housing; 9. Working chamber; 10. Mounting chamber; 11. Partition; 12. Upper chamber; 13. Lower chamber; 14. Crushing roller; 15. First motor; 16. Screen plate; 17. Mounting table; 18. Electric telescopic rod 1; 19. Screw feeder; 20. Mixing trough; 21. Connecting pipe 1; 22. Second motor; 23. Mixing roller; 24. Stirring blade; 25. Workbench; 26. Waste box; 27. Material trough; 28. Waste outlet; 29. ​​Mounting frame 1; 30. Mounting frame 2; 31. Electric telescopic rod 2; 32. Mounting Plate; 33. Sliding groove; 34. Center rod; 35. Sliding block; 36. Cutting knife; 37. Chassis; 38. Third motor; 39. Gear one; 40. Gear two; 41. Gear three; 42. Rotating axis one; 43. Rotating axis two; 44. Extrusion wheel; 45. Support platform; 46. Flame spray gun; 47. Limit block; 48. Gear four; 49. Connecting rod; 50. Dropping port; 51. Turntable; 52. Convex block; 53. Control board; 54. Feed hole; 55. Top plate one; 56. Spring one; 57. Lifting rod; 58. Top plate two; 59. Spring two; 60. Blocking block; 61. Conical surface; 62. Drive box; 63. Fourth motor; 64. Gear five; 65. Gear six. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0040] In addition, in the present invention, descriptions such as "first" and "second" are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] Example 1

[0042] An embodiment of the present invention provides a method for preparing a PE composite pipe, comprising:

[0043] Step S1, mixing high-density polyethylene and medium-density polyethylene in a specific ratio to obtain an outer layer mixture and an inner layer mixture respectively;

[0044] Step S2, grinding the outer layer mixture and the inner layer mixture into granules respectively and then sieving them to obtain the outer layer extrusion raw material and the inner layer extrusion raw material;

[0045] Step S3, adding the outer layer extrusion raw material and the inner layer extrusion raw material into the extruder respectively for extrusion to obtain the outer layer PE film and the inner layer PE film;

[0046] Step S4, using barrier glue to compound the outer PE film and the inner PE film to form a composite PE film;

[0047] Step S5: trimming the composite PE film, overlapping it, cooling it and shaping it to obtain a PE composite pipe.

[0048] Preferably, the raw materials of the inner layer mixture include, by weight: 80 parts of medium-density polyethylene, 6 parts of ceramic particles, 3 parts of lubricant, 2 parts of rare earth porcelain sand and 9 parts of polyolefin fiber fabric; the raw materials of the outer layer mixture include, by weight: 85 parts of high-density polyethylene, 5 parts of anti-ultraviolet agent, 8 parts of antioxidant and 2 parts of masterbatch.

[0049] The beneficial effects of the above technical solution are:

[0050] By grinding the outer layer mixture and the inner layer mixture into granules before extrusion, the size of the raw materials is reduced and the melting time of the raw materials is shortened. By screening the ground raw materials, it is prevented that oversized raw materials enter the extruder and are not completely melted, which affects the quality of the PE composite pipe. The PE pipe is prepared by compounding the outer PE film and the inner PE film, which can make the inner and outer layers of the PE pipe have different characteristics, thereby improving the quality of the PE pipe.

[0051] Example 2

[0052] An embodiment of the present invention also provides a PE composite pipe preparation system, which is used to prepare PE composite pipes using a PE composite pipe preparation method as described in Example 1, including two groups of base film manufacturing devices, a dry composite machine 1, a processing and detection device 2 and a tube forming device 3. The two groups of base film manufacturing devices are used to manufacture the outer PE film and the inner PE film, respectively. The dry composite machine 1 is used to composite the outer PE film and the inner PE film, the processing and detection device 2 is used to trim and detect the composite PE film, and the tube forming device 3 is used to overlap, cool and shape the composite PE film.

[0053] Preferably, the processing and detection device 2 includes a workbench 25, a waste box 26 is provided inside the workbench 25, a material trough 27 is provided on the upper surface of the workbench 25, and waste ports 28 are provided on the front and rear sides of the material trough 27 to communicate with the waste box 26, and the upper surface of the workbench 25 is fixedly connected with a mounting frame 1 29 and a mounting frame 2 30, and a camera is installed on the top surface of the mounting frame 20, and the camera is used to take real-time images of the composite PE film, and an electric telescopic rod 2 31 is fixedly connected to the top surface of the mounting frame 1 29, and the telescopic end of the electric telescopic rod 2 31 is fixedly connected to a mounting plate 32, and two groups of cutting components are symmetrically provided on the lower surface of the mounting plate 32, and the cutting component includes a sliding groove 33, and the sliding groove 33 is provided on the lower surface of the mounting plate 32, and a center rod 34 is fixedly connected in the sliding groove 33, and a sliding block 35 is slidably connected to the center rod 34 in the left and right directions, and a cutting knife 36 is fixedly connected to the lower surface of the sliding block 35.

[0054] Preferably, the tube forming device 3 includes a chassis 37, in which a third motor 38 is installed, and the output end of the third motor 38 is fixedly connected to a gear 1 39, on which a gear 2 40 and three gear 3s 41 are meshed, and the gear 2 40 is located above the gear 1 39, and the gear 2 40 is fixedly connected to the rotating shaft 1 42, and the three gear 3s 41 are respectively located on the left, right and bottom sides of the gear 1 39, and each gear 3 41 is fixedly connected to a rotating shaft 2 43, and the three rotating shafts 2 43 are respectively provided with limit blocks 47 at different positions, and the rotating shaft 1 42 and the rotating shaft 2 43 rotate through the outer wall of the chassis 37, and an extrusion wheel 44 is provided above the rotating shaft 1 42, and the extrusion wheel 44 is fixedly connected to the gear 4 48 by a connecting rod 49, and the gear 4 48 is meshed with the gear 2 40, and a support platform 45 is fixedly connected to the chassis 37, and a flame spray gun 46 is installed on the support platform 45.

[0055] Preferably, the base film manufacturing device includes a raw material processing device 4, a screw extruder 5 and a vertical traction machine 6. The raw material processing device 4 is used to crush the raw materials. The discharge port of the raw material processing device 4 is connected to the feed port of the screw extruder 5 through a feed pipe 7. The vertical traction machine 6 is arranged on the discharge port side of the screw extruder 5. The screw extruder 5 is used to pull the material strip extruded by the screw extruder 5.

[0056] In this embodiment, a locking assembly is provided inside the sliding block 35 , and the locking assembly is used to lock the position of the sliding block 35 on the center rod 34 .

[0057] The beneficial effects of the above technical solution are:

[0058] When preparing PE composite pipes, first, raw materials in a specific proportion are put into the raw material processing device for processing, and the processed raw materials are added to the screw extruder 5 for extrusion. The extruded material strip is pulled by the vertical traction machine 6 to obtain an outer PE film and an inner PE film. The outer PE film and the inner PE film are aligned and put into the dry compounding machine 1 for compounding to obtain a composite PE film. The produced composite PE film is first cut into a suitable size when passing through the processing and detection device 2, and then the appearance of the composite PE film is inspected by visual inspection. The inspected composite PE film is overlapped by the tube forming device 3 to form a tube to obtain a PE composite pipe.

[0059] When cutting the composite PE film, the cutting width can be adjusted by adjusting the position of the sliding block 35 on the center rod 34, and the cutting depth can be adjusted by adjusting the extension length of the telescopic rod 2, thereby ensuring that PE films of different widths and thicknesses can be cut, thereby improving the scope of application. The composite PE film after cutting is inspected for appearance by a camera to ensure that the appearance of the composite PE film is qualified, avoiding the unqualified PE composite pipe due to a small amount of unqualified composite PE film size or surface defects (surface with protrusions or holes), thereby ensuring the qualified rate of PE composite pipes.

[0060] When overlapping the composite PE film, the third motor 38 drives gear 1 39 to rotate, and through the engagement of gear 1 39 with gear 2 40 and gear 3 41, drives the rotating shaft 1 42 and the rotating shaft 2 43 to rotate. Before the composite PE film contacts the PE composite tube, it will first pass through the area of ​​the flame spray gun. Under the action of the flame spray gun 46, the composite PE film and the PE composite tube are softened, and then the composite PE film and the PE composite tube are fitted together. Under the extrusion action of the extrusion wheel 44 and the rotating shaft 1, as the contact surface moves away from the flame spray gun, the surface temperature of the composite PE film and the PE composite tube will decrease accordingly, thereby making the bonding between the composite PE film and the PE composite tube stable, and completing the preparation of the PE composite tube. During the rotation of the PE composite pipe, the edge of the PE composite pipe contacts the limit blocks 47 at different positions on different rotating shafts 43, so that the PE composite pipe continuously moves parallel to the direction away from the chassis 37, completing the adjustment of the position of the PE composite pipe and ensuring the continuity of the preparation of the PE composite pipe. The PE composite pipe is driven to rotate by the friction between the rotating shaft 1 42, the rotating shaft 2 43 and the PE composite pipe, reducing the contact area between the rotating shaft 1 42, the rotating shaft 2 43 and the PE composite pipe and the contact time of the same area, thereby avoiding the same area of ​​the PE composite pipe from being in contact with the rotating shaft 1 42, the rotating shaft 2 43 for a long time and causing adhesion, thereby causing damage to the PE composite pipe.

[0061] Example 3

[0062] On the basis of Example 2, the raw material processing device 4 includes a shell 8, a working chamber 9 and an installation chamber 10 are provided inside the shell 8, the working chamber 9 is divided into an upper chamber 12 and a lower chamber 13 by a partition 11, and a drop port 50 is provided on the partition 11, a crushing assembly is provided in the upper chamber 12, a sieve plate 16 is rotatably connected to the left side wall of the lower chamber 13, and a mounting platform 17 is fixedly connected to the right side wall of the lower chamber 13, an electric telescopic rod 18 is installed on the upper surface of the mounting platform 17, and the telescopic end of the electric telescopic rod 18 is hinged to the lower surface of the sieve plate 16, a screw conveyor 19 is installed in the installation chamber 10, the feed end of the screw conveyor 19 is connected to the lower chamber 13, and the discharge end of the screw conveyor 19 is connected to the upper chamber 12, a mixing trough 20 is fixedly connected to the outer wall of the shell 8, the discharge port of the mixing trough 20 is connected to the upper chamber 12 through a connecting pipe 21, and a mixing assembly is provided in the mixing trough 20.

[0063] Preferably, the raw material processing device 4 also includes a first motor 15, which is fixedly connected to the upper surface of the outer shell 8. The output end of the first motor 15 is fixedly connected to a turntable 51, and a convex block 52 is provided on the lower surface of the turntable 51. The upper wall of the outer shell 8 is slidably connected to a control board 53 along the up and down directions. The control board 53 passes through the connecting pipe 21, and a material passing hole 54 is provided on the control board 53. The upper end of the control board 53 is fixedly connected to a top plate 55, and a spring 56 is fixedly connected between the lower surface of the top plate 55 and the upper surface of the outer shell 8.

[0064] Preferably, the crushing assembly includes a lifting rod 57, the upper end of the lifting rod 57 is fixedly connected to a top plate 2 58, a spring 2 59 is fixedly connected between the lower surface of the top plate 2 58 and the upper surface of the outer shell 8, the lower end of the lifting rod 57 is fixedly connected to a blocking block 60, the upper end of the blocking block 60 is provided with a conical surface 61, the lifting rod 57 is fixedly connected to a drive box 62, the outer end of the lifting rod 57 is rotatably sleeved with a crushing roller 14, the crushing roller 14 is driven to rotate by a rotary drive device, and the rotary drive device is provided in the drive box 62.

[0065] In this embodiment, the rotation drive device includes a fourth motor 63, which is installed in the drive box 62. The output end of the fourth motor 63 is fixedly connected to the gear five 64. One end of the crushing roller 14 located in the drive box 62 is fixedly connected to the gear six 65. The gear five 64 and the gear six 65 are engaged for transmission.

[0066] In this embodiment, the mixing assembly includes a second motor 22, which is fixedly connected to the upper surface of the mixing tank 20. The output end of the second motor 22 is fixedly connected to a mixing roller 23, which rotates through the top surface of the mixing tank 20, and a number of stirring blades 24 are fixedly connected to the side wall of the mixing roller 23.

[0067] The beneficial effects of the above technical solution are:

[0068] When processing the raw materials, the unprocessed raw materials are first put into the mixing tank 20 and evenly mixed by the mixing components in the mixing tank 20. When crushing, the rotation drive device and the first motor 15 start working at the same time, and the rotation drive device drives the crushing roller 14 to rotate to complete the crushing of the raw materials in the upper cavity 12.

[0069] As the first motor 15 works, the turntable 51 starts to rotate. As the turntable 51 rotates, the convex block 52 intermittently squeezes the top plate 1 55 and the top plate 2 58. When the convex block 52 is located above the top plate 1 55, the convex block 52 squeezes the top plate 1 55, driving the control plate 53 to move downward, so that the through hole 54 is connected to the connecting pipe 1 21, so that the raw materials in the mixing tank 20 enter the upper cavity 12 through the connecting pipe 1 21. When the convex block 52 leaves the top plate 1 55, under the action of the spring 1 56, the control plate 53 moves upward, so that the through hole 54 is separated from the connecting pipe 1 21. At this time, the raw materials in the mixing tank 20 cannot enter the upper cavity 12. When the convex block 52 is located above the top plate 2 58, the convex block 52 squeezes the top plate 55. The second 58 drives the lifting rod 57 to move downward, so that the blocking block 60 leaves the blanking port 50, and the raw materials in the upper cavity 12 fall from the blanking port 50 onto the screen plate 16. The raw materials with qualified size pass through the screen plate 16 and fall below the screen plate 16, while the raw materials with unqualified size remain above the screen plate 16, enter the screw conveyor 19 along the screen plate 16, and are transported by the screw conveyor 19 to re-enter the upper cavity 12. When the protruding block leaves the top plate 58, the lifting rod 57 moves upward under the action of the spring 59, so that the blocking block 60 blocks the blanking port 50, ensuring that the raw materials in the upper cavity 12 will not fall from the blanking port 50. As the lifting rod 57 moves up and down, the crushing roller 14 also moves up and down, thereby improving the crushing effect.

[0070] By extending and retracting the electric telescopic rod 18, the screen plate 16 is driven to vibrate up and down, thereby ensuring the screening efficiency. By transporting the raw materials that do not meet the size requirements back to the upper cavity 12 for re-crushing, the utilization rate of the material is guaranteed and the waste of material is avoided. The turntable 51 simultaneously controls the movement of the lifting plate and the control plate 53, thereby reducing the energy loss and improving the convenience of control. At the same time, the synchronization of the movement of the lifting plate and the control plate 53 is guaranteed, and the idle operation of the device is avoided. By alternately lifting and lowering the lifting plate and the control plate 53, the automatic loading and unloading of the crushed raw materials are completed, which reduces the work intensity of the staff. At the same time, by driving the crushing roller 14 to move up and down, the crushing effect is improved. By loading and unloading materials at multiple frequencies, the continuity of the crushing is guaranteed while the number of crushed raw materials in each crushing cycle is reduced, further improving the crushing effect.

[0071] Example 4

[0072] On the basis of Example 2 or 3, a temperature monitoring module is provided in the screw extruder 5, and the temperature monitoring module includes:

[0073] Several thermocouples are provided inside the screw extruder 5 to detect the melt temperature at various locations of the screw extruder 5;

[0074] Temperature calculation unit, used to calculate theoretical extrusion temperature;

[0075]

[0076] Among them, T j is the theoretical extrusion temperature; T w is the melting temperature of the melt; σ1 and σ2 are the influence coefficients of mold length and mold cross-sectional area respectively; L0 is the preset reference mold length; L is the actual mold length; H is the actual mold height; D is the actual mold width; H0 is the preset reference mold height; D0 is the preset reference mold width; q is the heat flux density per unit area between the melt and the inner surface of the mold; t n is the preset maximum allowable solidification time; C is the specific heat capacity of the melt; V p is the preset reference extrusion speed; t0 is the unit time length; ρ w is the density of the melt; V S is the actual extrusion speed of the melt; μ s is the dynamic viscosity of the melt; ρ p is the reference value of the preset melt density; μ p It is the reference value of the preset melt dynamic viscosity;

[0077] The temperature judgment unit calculates the difference between the actual extrusion temperature measured by the thermocouple and the theoretical extrusion temperature. When the difference is greater than the preset danger threshold, an alarm is issued;

[0078] The temperature control unit is used to adjust the temperature of the last heating section of the screw extruder 5 to the target adjustment temperature when the temperature judgment unit alarms;

[0079] A regulating temperature calculation unit, used to calculate the target regulating temperature of the last heating section;

[0080]

[0081] Among them, T a The target temperature of the last heating section of the screw extruder 5 is adjusted; L j is the length of the last heating section of the screw extruder 5; π is the circumference of the circle; d is the inner diameter of the heating section; N is the screw speed; p is the screw pitch; t0 is the unit time length; h is the convective heat transfer coefficient of the melt; C is the specific heat capacity of the melt; ρ w is the density of the melt; V S is the actual extrusion speed of the melt; T j is the theoretical extrusion temperature; Tr It is the temperature of the melt when it enters the last heating section.

[0082] The beneficial effects of the above technical solution are:

[0083] By calculating the theoretical extrusion temperature, a reliable basis is provided for controlling the extrusion temperature of the screw extruder 5, ensuring that the melt can form the expected shape in the mold after being extruded, and that after the melt is formed and extruded out of the mold, it can solidify and form within a preset time, avoiding the occurrence of the "melt sag" phenomenon that causes deformation of the PE film and affects the quality of the PE composite pipe finally produced. By real-time monitoring of the difference between the actual extrusion temperature and the theoretical extrusion temperature, real-time monitoring of the extrusion temperature is completed, ensuring the stability of the extrusion temperature, guaranteeing the molding effect of the PE film, and thus maintaining the stable quality of the PE composite pipe.

[0084] When the extrusion temperature deviates too much, the extrusion temperature of the screw extruder 5 is adjusted by adjusting the temperature of the last heating section of the screw extruder 5, thereby ensuring the stability of the extrusion temperature of the screw extruder 5. The automatic adjustment of the extrusion temperature of the screw extruder 5 is completed by automatically adjusting the temperature of the last heating section of the screw extruder 5, thereby ensuring the stability of the extrusion temperature of the screw extruder 5. There is no need for manual adjustment by the staff, which improves the safety of the staff's work process, avoids the shutdown of the screw extruder 5, and ensures the production continuity of the PE composite pipe preparation system.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a PE composite pipe, characterized in that: include: Step S1, mixing high-density polyethylene and medium-density polyethylene in a specific ratio to obtain an outer layer mixture and an inner layer mixture respectively; Step S2: Grinding the outer layer mixture and the inner layer mixture into granules and then sieving them to obtain an outer layer extrusion raw material and an inner layer extrusion raw material; wherein the raw materials of the inner layer mixture include, by weight, 80 parts of medium-density polyethylene, 6 parts of ceramic particles, 3 parts of lubricant, 2 parts of rare earth porcelain sand, and 9 parts of polyolefin fiber fabric; and the raw materials of the outer layer mixture include, by weight, 85 parts of high-density polyethylene, 5 parts of anti-ultraviolet agent, 8 parts of antioxidant, and 2 parts of masterbatch; Step S3, adding the outer layer extrusion raw material and the inner layer extrusion raw material into the extruder respectively for extrusion to obtain the outer layer PE film and the inner layer PE film; Step S4, using barrier glue to compound the outer PE film and the inner PE film to form a composite PE film; Step S5, trimming the composite PE film, overlapping it, cooling it and shaping it, to obtain a PE composite pipe; Among them, the preparation of PE composite pipe is realized based on the base film manufacturing device; The base film manufacturing device comprises a screw extruder (5), and a temperature monitoring module is provided in the screw extruder (5), and the temperature monitoring module comprises: A plurality of thermocouples are arranged inside the screw extruder (5) and are used to detect the melt temperature at various locations of the screw extruder (5); Temperature calculation unit, used to calculate theoretical extrusion temperature; Among them, T j is the theoretical extrusion temperature; T w is the melting temperature of the melt; σ1 and σ2 are the influence coefficients of mold length and mold cross-sectional area respectively; L0 is the preset reference mold length; L is the actual mold length; H is the actual mold height; D is the actual mold width; H0 is the preset reference mold height; D0 is the preset reference mold width; q is the heat flux density per unit area between the melt and the inner surface of the mold; t n is the preset maximum allowable solidification time; C is the specific heat capacity of the melt; V p is the preset reference extrusion speed; t0 is the unit time length; ρ w is the density of the melt; V S is the actual extrusion speed of the melt; μ s is the dynamic viscosity of the melt; ρ p is the reference value of the preset melt density; μ p It is the reference value of the preset melt dynamic viscosity; The temperature judgment unit calculates the difference between the actual extrusion temperature measured by the thermocouple and the theoretical extrusion temperature. When the difference is greater than the preset danger threshold, an alarm is issued; A temperature control unit is used to adjust the temperature of the last heating section of the screw extruder (5) to a target adjustment temperature when the temperature judgment unit alarms; A regulating temperature calculation unit, used to calculate the target regulating temperature of the last heating section; Among them, T a The target temperature of the last heating section of the screw extruder (5) is adjusted; L j is the length of the last heating section of the screw extruder (5); π is the circumference of the circle; d is the inner diameter of the heating section; N is the screw speed; p is the screw pitch; t0 is the unit time length; h is the convective heat transfer coefficient of the melt; C is the specific heat capacity of the melt; ρ w is the density of the melt; V S is the actual extrusion speed of the melt; T j is the theoretical extrusion temperature; T r It is the temperature of the melt when it enters the last heating section.

2. A PE composite pipe preparation system, used for preparing a PE composite pipe using a PE composite pipe preparation method according to claim 1, characterized in that: The invention comprises two groups of base film manufacturing devices, a dry laminating machine (1), a processing and detecting device (2) and a tube forming device (3). The two groups of base film manufacturing devices are used to manufacture an outer PE film and an inner PE film respectively. The dry laminating machine (1) is used to laminate the outer PE film and the inner PE film. The processing and detecting device (2) is used to trim and detect the composite PE film. The tube forming device (3) is used to overlap, cool and shape the composite PE film.

3. A PE composite pipe preparation system according to claim 2, characterized in that: The processing and detecting device (2) includes a workbench (25), a waste box (26) is provided inside the workbench (25), a material trough (27) is provided on the upper surface of the workbench (25), waste openings (28) are provided on the front and rear sides of the material trough (27) and are communicated with the waste box (26), a mounting frame 1 (29) and a mounting frame 2 (30) are fixedly connected to the upper surface of the workbench (25), a camera is installed on the inner top surface of the mounting frame 2 (30), and the camera is used to capture a real-time image of the composite PE film. The electric telescopic rod (31) is fixedly connected, and the telescopic end of the electric telescopic rod (31) is fixedly connected to the mounting plate (32). Two groups of cutting components are symmetrically arranged on the lower surface of the mounting plate (32). The cutting components include a sliding groove (33). The sliding groove (33) is arranged on the lower surface of the mounting plate (32). A center rod (34) is fixedly connected in the sliding groove (33). A sliding block (35) is slidably connected to the center rod (34) along the left and right directions. A cutting knife (36) is fixedly connected to the lower surface of the sliding block (35).

4. A PE composite pipe preparation system according to claim 2, characterized in that: The tube forming device (3) includes a chassis (37), a third motor (38) is installed in the chassis (37), the output end of the third motor (38) is fixedly connected to a gear 1 (39), a gear 2 (40) and three gear 3s (41) are meshed on the gear 1 (39), the gear 2 (40) is located above the gear 1 (39), the gear 2 (40) is fixedly connected to the rotating shaft 1 (42), the three gear 3s (41) are respectively located on the left side, the right side and the bottom side of the gear 1 (39), and each gear 3 (41) is fixedly connected to a gear 2 (40). A second rotating shaft (43) is provided, and the three second rotating shafts (43) are respectively provided with limit blocks (47) at different positions. The first rotating shaft (42) and the second rotating shaft (43) rotate and penetrate the outer wall of the chassis (37). An extrusion wheel (44) is provided above the first rotating shaft (42). The extrusion wheel (44) is fixedly connected to the fourth gear (48) through a connecting rod (49). The fourth gear (48) is meshed with the second gear (40). A support platform (45) is fixedly connected to the chassis (37), and a flame spray gun (46) is installed on the support platform (45).

5. A PE composite pipe preparation system according to claim 2, characterized in that: The base film manufacturing device includes a raw material processing device (4), a screw extruder (5) and a vertical traction machine (6). The raw material processing device (4) is used to crush the raw material. The discharge port of the raw material processing device (4) is connected to the feed port of the screw extruder (5) through a feed pipe (7). The vertical traction machine (6) is arranged on the discharge port side of the screw extruder (5). The screw extruder (5) is used to traction the material strip extruded by the screw extruder (5).

6. A PE composite pipe preparation system according to claim 5, characterized in that: The raw material processing device (4) includes a shell (8), a working chamber (9) and a mounting chamber (10) are provided inside the shell (8), the working chamber (9) is divided into an upper chamber (12) and a lower chamber (13) by a partition (11), a material drop opening (50) is provided on the partition (11), a crushing assembly is provided in the upper chamber (12), a sieve plate (16) is rotatably connected to the left side wall of the lower chamber (13), a mounting platform (17) is fixedly connected to the right side wall of the lower chamber (13), and an electric telescopic Rod one (18), the telescopic end of the electric telescopic rod one (18) is hinged to the lower surface of the screen plate (16), a screw conveyor (19) is installed in the installation cavity (10), the feed end of the screw conveyor (19) is communicated with the lower cavity (13), the discharge end of the screw conveyor (19) is communicated with the upper cavity (12), a mixing trough (20) is fixedly connected to the outer wall of the shell (8), the discharge port of the mixing trough (20) is communicated with the upper cavity (12) through a connecting pipe one (21), and a mixing component is provided in the mixing trough (20).

7. A PE composite pipe preparation system according to claim 6, characterized in that: The raw material processing device (4) also includes a first motor (15), which is fixedly connected to the upper surface of the housing (8), and the output end of the first motor (15) is fixedly connected to a turntable (51), and a convex block (52) is provided on the lower surface of the turntable (51). The upper wall of the housing (8) is slidably connected to a control plate (53) along the upper and lower directions, and the control plate (53) passes through the connecting pipe (21). A material through hole (54) is provided on the control plate (53), and the upper end of the control plate (53) is fixedly connected to a top plate (55), and a spring (56) is fixedly connected between the lower surface of the top plate (55) and the upper surface of the housing (8).

8. A PE composite pipe preparation system according to claim 7, characterized in that: The crushing assembly includes a lifting rod (57), the upper end of the lifting rod (57) is fixedly connected to a top plate (58), a spring (59) is fixedly connected between the lower surface of the top plate (58) and the upper surface of the shell (8), the lower end of the lifting rod (57) is fixedly connected to a blocking block (60), the upper end of the blocking block (60) is provided with a conical surface (61), the lifting rod (57) is fixedly connected to a driving box (62), the lifting rod (57) is rotatably sleeved with a crushing roller (14), and the crushing roller (14) is driven to rotate by a rotating driving device, and the rotating driving device is provided in the driving box (62).

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