Single screw extruder for PE pipe production

Abstract

The invention relates to a single-screw extruder for producing PE pipes, and relates to the technical field of plastic molding. The extrusion die comprises an extrusion die adjustment system, a pressurized bonding system, a vacuum cooling system and a traction system. The extrusion die has an annular outlet, the traction system is installed in the vacuum cooling system, the pressurized bonding system is installed at the end of the extrusion die, the pressurized bonding system is installed in the annular outlet, the pressurized bonding system can be expanded toward the vacuum cooling system, and the expansion direction of the pressurized bonding system points to the annular outlet. A traction tube is preset in the traction system, the traction system is transmission-connected with the traction tube, the annular outlet is used to extrude molten material, and the pressurized bonding system approaches the periphery of the annular outlet when expanded, and then presses against the inner side wall of the traction tube, and then squeezes the molten material toward the inner side wall of the traction tube, and the production efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of plastic molding, in particular to a single-screw extruder for producing PE pipes. Background Art

[0002] The production process of PE pipes mainly includes the following steps: raw material selection, extrusion molding, cooling and sizing, cutting and stacking, quality inspection, and packaging and warehousing.

[0003] The main raw material of PE pipes is polyethylene (PE). Different types and grades of polyethylene are selected according to the purpose and requirements of the pipes, such as high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and cross-linked polyethylene (PEX). The selection of raw materials should take into account factors such as the use environment, pressure resistance and corrosion resistance of the pipes.

[0004] Extrusion molding is the main production process of PE pipes. Pre-mixed polyethylene granules are placed in the hopper of the extruder, and the polyethylene is melted by heating and pressure. The molten polyethylene is extruded into a pipe with a circular cross-section through the screw and die of the extruder. Parameters such as the temperature, pressure and extrusion speed of the extruder need to be adjusted according to different polyethylene types and pipe specifications.

[0005] The extruded PE pipe needs to be cooled using a vacuum cooling system, usually water cooling, which is sprayed on the pipe through a cooling water tank to quickly reduce the surface temperature. The temperature and flow of the cooling water need to be adjusted according to the specifications and production speed of the pipe to ensure the quality and performance of the pipe. The cooled pipe also needs to be sized to control its outer diameter to ensure the accuracy and consistency of the product.

[0006] When the existing pipe is melt extruded, it is necessary to place a traction tube in the vacuum cooling system first, and then adhere the just extruded molten pipe to the traction tube, so that the traction tube can pull the molten pipe into the vacuum cooling system for cooling and continuous molding. Summary of the invention

[0007] In order to overcome the technical defects of the prior art, the present invention provides a single-screw extruder for PE pipe production, which has high production efficiency.

[0008] The technical solution adopted by the present invention is:

[0009] A single-screw extruder for PE pipe production includes an extrusion die, a die adjustment system, a pressurized bonding system, a vacuum cooling system and a traction system, wherein the extrusion die has an annular outlet, the traction system is installed in the vacuum cooling system, the pressurized bonding system is installed at the end of the extrusion die, the pressurized bonding system is installed in the annular outlet, the pressurized bonding system can be expanded toward the vacuum cooling system, and the expansion direction of the pressurized bonding system points to the annular outlet. A traction tube is preset in the traction system, and the traction system is transmission-connected to the traction tube. The annular outlet is used to extrude molten material. When the pressurized bonding system is expanded, it approaches the periphery of the annular outlet and then presses against the inner wall of the traction tube, thereby squeezing the molten material toward the inner wall of the traction tube.

[0010] Preferably, the extrusion die is externally connected to a melt extrusion system.

[0011] Preferably, the mold adjustment system includes a mold support frame, a mold support shaft and a mold swing cylinder, the mold support shaft is installed on the side of the extrusion mold, the mold support shaft is rotatably installed on the mold support frame, and the mold swing cylinder is transmission-connected to the mold support shaft.

[0012] Preferably, the pressurized bonding system includes two traction and pressurizing devices and two pressurizing power devices, each of the traction and pressurizing devices is rotatably mounted on the extrusion die, the traction and pressurizing device is mounted on the inner side of the annular outlet, the pressurizing power device is rotatably mounted on the extrusion die, the pressurizing power device is mounted on the inner side of the annular outlet, and each of the pressurizing power devices is transmission-connected to the corresponding traction and pressurizing device.

[0013] Preferably, the traction and pressurizing device includes a traction rod and a heating ring, a plurality of electric heating blocks are provided on the outer circumference of the heating ring, the traction rod is rotatably mounted on the extrusion die, the traction and pressurizing device is mounted in the annular outlet, and the heating ring is mounted on the traction rod.

[0014] Preferably, the pressurizing power device includes a pressurizing power motor and a pressurizing shaft, the pressurizing power motor is transmission-connected to the corresponding pressurizing shaft, and each pressurizing shaft is mounted on a corresponding traction rod.

[0015] Preferably, the traction and pressurizing devices are installed in a stacked manner, and the traction and pressurizing device that is further away from the vacuum cooling system is provided with an opening for the passage of another traction and pressurizing device.

[0016] Preferably, the traction system has several traction rollers.

[0017] The beneficial effects of the present invention are:

[0018] The extrusion die has an annular outlet, which is used to extrude the molten pipe. The traction system is installed in the vacuum cooling system. The vacuum cooling system belongs to a conventional water cooling system in the field and will not be described in detail here. The vacuum cooling system has a traction system, which is also a conventional design in the field and will not be described in detail here. The pressurized bonding system is installed at the end of the extrusion die, and the pressurized bonding system is installed in the annular outlet. The pressurized bonding system can be expanded in the direction of the vacuum cooling system, and the expansion direction of the pressurized bonding system points to the annular outlet. A traction tube is preset in the traction system, and the traction system and the traction tube are transmitted. The pressurized bonding system is dynamically connected, thereby driving the traction tube to be transported into the vacuum cooling system. The annular outlet is used to extrude the molten material. When the pressurized bonding system is expanded, it approaches the periphery of the annular outlet, thereby pressing against the inner wall of the traction tube, thereby squeezing the molten material toward the inner wall of the traction tube. When the pressurized bonding system is expanded toward the vacuum cooling system, the pressurized bonding system squeezes and adheres the molten material to the inner wall of the traction tube, so that the molten material and the traction tube are bonded to each other, which is convenient for the traction tube to continuously pull out the molten material, thereby realizing continuous molding. There is no need to manually bond the molten material and the traction tube, and the production efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention.

[0020] Figure 2 This is a schematic diagram of the mold adjustment system structure.

[0021] Figure 3 Schematic diagram of the pressurized bonding system structure.

[0022] Figure 4 Schematic diagram of the bonding principle of the pressurized bonding system.

[0023] Description of reference numerals:

[0024] 1. Extrusion die; 11. Annular outlet;

[0025] 2. Mold adjustment system; 21. Mold support frame; 22. Mold support shaft; 23. Mold swing cylinder;

[0026] 3. Pressurized bonding system; 31. Traction pressurized device; 311. Traction rod; 312. Heating ring; 3121. Opening; 32. Pressurized power device; 321. Pressurized power motor; 322. Pressurized shaft;

[0027] 4. Vacuum cooling system;

[0028] 5. Traction tube. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings:

[0030] like Figure 1 — Figure 4 As shown, this embodiment provides a single-screw extruder for PE pipe production, including an extrusion die 1, a die adjustment system 2, a pressurized bonding system 3, a vacuum cooling system 4 and a traction system. The extrusion die 1 has an annular outlet 11, and the annular outlet 11 is used to extrude the molten pipe. The traction system is installed in the vacuum cooling system 4. The vacuum cooling system 4 belongs to a conventional water cooling system in the field and will not be repeated here. The vacuum cooling system 4 has a traction system, which is also a conventional design in the field and will not be repeated here. The pressurized bonding system 3 is installed at the end of the extrusion die 1, and the pressurized bonding system 3 is installed in the annular outlet 11. The pressurized bonding system 3 can be expanded toward the vacuum cooling system 4. The expansion direction of the pressurized bonding system 3 is The annular outlet 11 is pointed to, and a traction tube 5 is preset in the traction system. The traction system is transmission-connected to the traction tube 5, thereby driving the traction tube 5 to be transported into the vacuum cooling system 4. The annular outlet 11 is used to extrude the molten material. When the pressurized bonding system 3 is unfolded, it approaches the periphery of the annular outlet 11, thereby pressing against the inner wall of the traction tube 5, thereby squeezing the molten material toward the inner wall of the traction tube 5. When the pressurized bonding system 3 is unfolded toward the vacuum cooling system 4, the pressurized bonding system 3 extrude and adhere the molten material to the inner wall of the traction tube 5, so that the molten material and the traction tube 5 are bonded to each other, which facilitates the traction tube 5 to continuously pull out the molten material, thereby realizing continuous molding, and there is no need to manually bond the molten material and the traction tube 5, thereby achieving high production efficiency.

[0031] Specifically, the extrusion die 1 is externally connected to a melt extrusion system for melt extruding PE material. The melt extrusion system is a conventional single-screw extrusion system in the art. The molten material is extruded from the annular outlet 11 of the extrusion die 1 to achieve pipe forming.

[0032] Specifically, the mold adjustment system 2 includes a mold support frame 21, a mold support shaft 22 and a mold swing cylinder 23. The mold support shaft 22 is installed on the side of the extrusion mold 1. The mold support shaft 22 is rotatably installed on the mold support frame 21 through a bearing. The mold swing cylinder 23 is connected to the mold support shaft 22 through a connecting rod transmission. The mold swing cylinder 23 is used to drive the mold support shaft 22 to rotate, thereby rotating the extrusion mold 1, and then adjusting the annular outlet 11 to the same height as the vacuum cooling system 4, to ensure that the extrusion mold 1 and the vacuum cooling system 4 are smoothly connected.

[0033] Specifically, a track is provided at the bottom of the vacuum cooling system 4, which allows the vacuum cooling system 4 to be close to or away from the extrusion die 1. Specifically, when the molten material and the traction tube 5 are adhered to each other, the vacuum cooling system 4 is away from the extrusion die 1, thereby providing space for the pressurized bonding system 3 to unfold. After the molten material and the traction tube 5 are adhered and the traction tube 5 is pulled into the vacuum cooling system 4 by the traction system, the vacuum cooling system 4 is close to the extrusion die 1 to prevent the molten material just extruded from the extrusion die 1 from collapsing and deforming under the action of gravity.

[0034] Specifically, the pressurized bonding system 3 includes two traction and pressurizing devices 31 and two pressurizing power devices 32. Each traction and pressurizing device 31 is rotatably installed on the extrusion die 1. The traction and pressurizing device 31 is installed on the inner side of the annular outlet 11. The pressurizing power device 32 is rotatably installed on the extrusion die 1. The pressurizing power device 32 is installed on the inner side of the annular outlet 11. Each pressurizing power device 32 is transmission-connected with the corresponding traction and pressurizing device 31. The pressurizing power device 32 drives the corresponding traction and pressurizing device 31 to extrude the molten material onto the traction tube 5, so that the traction tube 5 can pull out the molten material.

[0035] Specifically, the traction and pressure device 31 includes a traction rod 311 and a heating ring 312. A plurality of electric heating blocks are arranged on the outer periphery of the heating ring 312. In order to make the molten material fit with the traction tube 5, each heating ring 312 is made of elastic spring steel sheets. The traction rod 311 is rotatably installed on the extrusion die 1. The traction and pressure device 31 is installed in the annular outlet 11. The heating ring 312 is installed on the traction rod 311. The heating ring 312 ensures and maintains the temperature of the molten material, thereby making the molten material and the traction tube 5 fit more tightly.

[0036] Specifically, the pressurizing power device 32 includes a pressurizing power motor 321 and a pressurizing shaft 322. The pressurizing power motor 321 is transmission-connected to the corresponding pressurizing shaft 322. Each pressurizing shaft 322 is installed on the corresponding traction rod 311. It is worth noting that the pressurizing power motor 321 is an H-class motor, which is convenient for withstanding the temperature of the molten material. The pressurizing power motor 321 drives the pressurizing shaft 322 to rotate, thereby controlling the corresponding traction rod 311 to rotate.

[0037] Specifically, the traction and pressurizing devices 31 are installed in a stacked manner, and the traction and pressurizing device 31 farther away from the vacuum cooling system 4 is provided with an opening 3121 for the passage of another traction and pressurizing device 31. Specifically, the opening 3121 is for the traction rod 311 of the other traction and pressurizing device 31 to pass through, thereby preventing interference. In order to ensure the smooth stacking of the two traction and pressurizing devices 31, the traction and pressurizing device 31 with the opening 3121 is unfolded and bonded later, but is retracted earlier after bonding.

[0038] Specifically, the traction system is composed of a plurality of traction rollers pulled by motors, and each traction roller pulls out the traction tube 5, i.e., the cooled PE tube.

[0039] The working process of the present invention is:

[0040] First, the vacuum cooling system 4 is slid along the track away from the extrusion die 1, and the traction tube 5 is installed on the traction system. Then, the traction system pulls the traction tube 5 close to the extrusion die 1. The extrusion die 1 is aligned with the vacuum cooling system 4 under the traction of the die swing cylinder 23. The pressurizing power device 32 drives the traction and pressurizing device 31 to rotate so that the traction and pressurizing device 31 squeezes the molten material onto the traction tube 5, thereby achieving bonding between the molten material and the traction tube 5. The traction system then pulls the traction tube 5 in the direction close to the vacuum cooling system 4, so that the molten material moves continuously in the direction of the vacuum cooling system 4 to achieve cooling.

[0041] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. Single screw extruder for PE pipe production, characterized by: The invention comprises an extrusion die, a die adjustment system, a pressurized bonding system, a vacuum cooling system and a traction system, wherein the extrusion die has an annular outlet, the traction system is installed in the vacuum cooling system, the pressurized bonding system is installed at the end of the extrusion die, the pressurized bonding system is installed in the annular outlet, the pressurized bonding system can be expanded toward the vacuum cooling system, and the expansion direction of the pressurized bonding system points to the annular outlet, a traction tube is preset in the traction system, the traction system is connected to the traction tube in a transmission manner, the annular outlet is used to extrude molten material, the pressurized bonding system approaches the periphery of the annular outlet when expanded, and then presses against the inner wall of the traction tube, thereby squeezing the molten material toward the inner wall of the traction tube, and the pressurized bonding system comprises two traction and pressurized Device and two pressurizing power devices, each of the traction and pressurizing devices is rotatably mounted on the extrusion die, the traction and pressurizing device is mounted on the inner side of the annular outlet, the pressurizing power device is rotatably mounted on the extrusion die, the pressurizing power device is mounted on the inner side of the annular outlet, each of the pressurizing power devices is transmission-connected with the corresponding traction and pressurizing device, the traction and pressurizing device includes a traction rod and a heating ring, a plurality of electric heating blocks are provided on the outer periphery of the heating ring, the traction rod is rotatably mounted on the extrusion die, the traction and pressurizing device is mounted in the annular outlet, the heating ring is mounted on the traction rod, the pressurizing power device includes a pressurizing power motor and a pressurizing shaft, the pressurizing power motor is transmission-connected with the corresponding pressurizing shaft, and each pressurizing shaft is mounted on the corresponding traction rod.

2. The single screw extruder for PE pipe production according to claim 1, characterized in that: The extrusion die is externally connected with a melt extrusion system.

3. The single screw extruder for PE pipe production according to claim 1, characterized in that: The mold adjustment system includes a mold support frame, a mold support shaft and a mold swing cylinder. The mold support shaft is installed on the side of the extrusion mold. The mold support shaft is rotatably installed on the mold support frame. The mold swing cylinder is transmission-connected to the mold support shaft.

4. The single screw extruder for PE pipe production according to claim 1, characterized in that: The two traction and pressurizing devices are installed in a stacked manner, and the traction and pressurizing device farther away from the vacuum cooling system is provided with an opening for the other traction and pressurizing device to pass through.

5. The single screw extruder for PE pipe production according to claim 1, characterized in that: The traction system has several traction rollers.

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