Plunger type screw for plasticizing ultra-high molecular weight polyethylene

Abstract

The utility model belongs to the technical field of screws, and particularly relates to a plunger type screw for plasticizing ultra-high molecular weight polyethylene, which comprises a charging barrel, a hopper and a material spraying assembly, the charging barrel is of a hollow structure, a material injection cavity is arranged on the charging barrel, a screw is arranged in the material injection cavity, the charging barrel is connected with a flange, the material spraying assembly comprises a nozzle and a nozzle, and the nozzle is connected with the hopper. The nozzle and the nozzle are both arranged in a manner of being matched with the flange, the nozzle and the nozzle are both arranged in a manner of being matched with the material injection cavity, the screw rod is provided with a screw rod head, the screw rod head is provided with a non-return ring, the inner wall of the material injection cavity is provided with two groups of mesons which are symmetrically arranged, and the two groups of mesons are both arranged in a manner of being matched with the screw rod. Through the design of stirring self-adaption, efficient plasticizing and pressure stabilization, a complete process chain is formed with a temperature control system, an exhaust system and a mold filling system of a mold, and the forming efficiency and the product quality of ultra-high molecular weight polyethylene are remarkably improved.

Description

Technical Field

[0001] This utility model belongs to the field of screw technology, specifically relating to a plug-type screw for plasticizing ultra-high molecular weight polyethylene. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMW-PE) typically refers to linear polyethylene with a relative molecular mass of over 1.5 million. It is a class of high-performance thermoplastic engineering plastics, possessing advantages such as impact resistance, corrosion resistance, wear resistance, self-lubrication, non-toxicity, and excellent low-temperature resistance. Furthermore, the wear resistance of UHMW-PE significantly improves with increasing molecular weight. The extremely long molecular chains of UHMW-PE cause them to become entangled, making it difficult for them to arrange themselves in a regular pattern. This leads to changes in the aggregation state, while the random entanglement between macromolecular chains also slows down the thermal response of UHMW-PE. When heated above its melting point, the melt exhibits a rubbery, highly viscoelastic state with a melt viscosity as high as 10⁸ Pa·s and a melt flow rate almost zero. This results in a very low critical shear rate for UHMW-PE, making it prone to defects such as melt fracture. Therefore, a screw is required during the processing of UHMW-PE.

[0003] Existing split-type screw extruders suffer from uneven material mixing, poor mixing effect when bulk density changes, easy backflow of molten material during screw plasticizing, unstable injection pressure, insufficient shear force during material plasticizing, low melting efficiency, large vibration of mixing components, poor equipment operation stability, and lack of parameter linkage control, making it difficult to meet the sensitive plasticizing requirements of ultra-high molecular weight polyethylene. To address these issues, we propose a plug-type screw extruder for ultra-high molecular weight polyethylene plasticizing. Utility Model Content

[0004] The purpose of this invention is to provide a plug-type screw for plasticizing ultra-high molecular weight polyethylene (UHMWPE). Through its design of adaptive stirring, high-efficiency plasticizing, and stable pressure, it forms a complete process chain with the temperature control, venting, and filling systems of the mold, significantly improving the molding efficiency and product quality of UHMWPE.

[0005] The specific technical solution adopted by this utility model is as follows:

[0006] A plug-type screw for plasticizing ultra-high molecular weight polyethylene includes a barrel, a hopper, and a spraying assembly. The barrel has a hollow structure and an injection chamber. The screw is installed inside the injection chamber. A flange is connected to the barrel. The spraying assembly includes a nozzle and an injection tip. Both the nozzle and the injection tip are matched with the flange and the injection chamber.

[0007] In a preferred embodiment, the screw is provided with a screw head, the screw head is provided with a check ring, and the inner wall of the injection cavity is provided with two sets of symmetrically arranged media, and both sets of media are matched with the screw.

[0008] In a preferred embodiment, the hopper is equipped with a PLC system motor, the output end of which is connected to a stirring shaft. A set of combined fan blades is snapped onto both sides of the stirring shaft. Each set of combined fan blades includes multiple inclined fan blade bodies, and the two sets of fan blade bodies are spaced apart.

[0009] In a preferred embodiment, the fan blade body includes a first fan blade, the first fan blade is provided with a sliding groove, a sliding block is provided in the sliding groove, the sliding block is slidably connected to the inner walls on both sides of the sliding groove, one end of the sliding block is connected to a second fan blade, and the other end of the sliding block is connected to the bottom wall of the sliding groove through a first return spring.

[0010] In a preferred embodiment, the sliding block has mounting grooves on both side walls, and the openings of the two mounting grooves face the inner walls of the two side walls of the sliding groove respectively. Mounting blocks are slidably connected in both mounting grooves, mounting rods are fixedly connected to both mounting blocks, and buffer rollers are rotatably connected to both mounting rods.

[0011] In a preferred embodiment, two symmetrically arranged second reset springs are snapped onto the mounting block, and the second reset springs are snapped onto the bottom wall of the mounting groove. Both the first reset spring and the second reset spring are damping springs.

[0012] The technical effects achieved by this utility model are as follows:

[0013] Ultra-high molecular weight polyethylene granules are added through the hopper. The PLC system motor drives the stirring shaft to rotate, which in turn drives the first and second blades to mix the material. The second blade is connected to the sliding groove of the first blade through a sliding block. When subjected to material resistance, the first return spring can be compressed to automatically adjust the spacing to adapt to materials with different bulk densities. The buffer roller is pressed against the inner wall of the hopper through the second return spring to reduce the impact vibration during stirring and ensure that the material is evenly delivered to the injection chamber of the barrel. The screw rotates and pushes the material towards the spraying assembly. The spacers on the inner wall of the injection chamber cooperate with the screw to form a shear force field, which promotes the melting and plasticization of the material. The check ring on the screw head seals the molten material channel when the screw advances to prevent high-pressure molten material backflow and ensure stable pressure during the injection molding stage. The plasticized molten material is extruded through the nozzle and injection nozzle, and then connected to the mold nozzle through the flange to complete the filling of the mold cavity. The axial thrust of the screw is transmitted to the mold through the molten material. Combined with the short and thick inlet design of the mold, high-speed mold filling is achieved. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a plug-type screw for plasticizing ultra-high molecular weight polyethylene proposed in this utility model;

[0015] Figure 2This is a schematic diagram of the connection state between the screw and the nozzle of a plug-type screw for plasticizing ultra-high molecular weight polyethylene proposed in this utility model.

[0016] Figure 3 This is a schematic diagram of the hopper of a plug-type screw for plasticizing ultra-high molecular weight polyethylene proposed in this utility model;

[0017] Figure 4 This is a schematic diagram of the fan blade body of a plug-type screw for plasticizing ultra-high molecular weight polyethylene proposed in this utility model;

[0018] Figure 5 for Figure 4 A schematic diagram of point A in the middle.

[0019] In the diagram: 1. Material cylinder, 2. Hopper, 3. Injection chamber, 4. Screw, 5. Flange, 6. Nozzle, 7. Injection nozzle, 8. Screw head, 9. Check ring, 10. Mesh, 11. PLC system motor, 12. Stirring shaft, 13. First fan blade, 14. Sliding groove, 15. Sliding block, 16. First return spring, 17. Mounting groove, 18. Mounting block, 19. Mounting rod, 20. Buffer roller, 21. Second return spring, 22. Second fan blade. Detailed Implementation

[0020] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0023] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.

[0024] Please see Figure 1-5As shown, this utility model provides a plug-type screw for plasticizing ultra-high molecular weight polyethylene, including a barrel 1, a hopper 2, and a spraying assembly. The barrel 1 has a hollow structure and is provided with a filling chamber 3. A screw 4 is provided inside the filling chamber 3. A flange 5 is connected to the barrel 1. The spraying assembly includes a nozzle 6 and a nozzle 7. Both the nozzle 6 and the nozzle 7 are matched with the flange 5 and the filling chamber 3.

[0025] The screw 4 is provided with a screw head 8, and the screw head 8 is provided with a check ring 9. The inner wall of the injection chamber 3 is provided with two sets of symmetrically arranged media 10, and both sets of media 10 are matched with the screw 4.

[0026] The hopper 2 is equipped with a PLC system motor 11. The output end of the PLC system motor 11 is connected to a stirring shaft 12. A set of combined fan blades is snapped onto both sides of the stirring shaft 12. Both sets of combined fan blades include multiple inclined fan blade bodies, and the two sets of fan blade bodies are spaced apart.

[0027] The fan blade body includes a first fan blade 13, a sliding groove 14 is provided on the first fan blade 13, a sliding block 15 is provided in the sliding groove 14, the sliding block 15 is slidably connected to the inner walls on both sides of the sliding groove 14, one end of the sliding block 15 is connected to a second fan blade 22, and the other end of the sliding block 15 is connected to the bottom wall of the sliding groove 14 through a first reset spring 16.

[0028] The sliding block 15 has mounting grooves 17 on both sides of its sidewalls, and the openings of the two mounting grooves 17 face the inner walls of the two sides of the sliding groove 14 respectively. Mounting blocks 18 are slidably connected in both mounting grooves 17, and mounting rods 19 are fixedly connected to both mounting blocks 18. Buffer rollers 20 are rotatably connected to both mounting rods 19.

[0029] Two symmetrically arranged second return springs 21 are snapped onto the mounting block 18, and the second return springs 21 are snapped onto the bottom wall of the mounting groove 17. Both the first return spring 16 and the second return spring 21 are damping springs.

[0030] In this invention, ultra-high molecular weight polyethylene granules are added through hopper 2. The PLC system motor 11 drives the stirring shaft 12 to rotate, which in turn drives the first blade 13 and the second blade 22 to mix the materials. The second blade 22 is connected to the sliding groove 14 of the first blade 13 through a sliding block 15. When subjected to material resistance, the first return spring 16 can be compressed to automatically adjust the spacing to adapt to materials with different bulk densities. The buffer roller 20 is pressed tightly against the inner wall of the hopper through the second return spring 21 to reduce the impact vibration during stirring and ensure that the materials are evenly delivered to the feeding cylinder 1. In cavity 3, the screw 4 rotates and pushes the material towards the injection assembly. The spacer 10 on the inner wall of the injection cavity 3 cooperates with the screw 4 to form a shear force field, which promotes the melting and plasticization of the material. The check ring 9 of the screw head 8 seals the molten material channel when the screw advances to prevent the high-pressure molten material from flowing back and to ensure stable pressure during the injection stage. The plasticized molten material is extruded through the nozzle 6 and the injection nozzle 7, and then connected to the mold nozzle 6 through the flange 5 to complete the filling of the mold cavity. The axial thrust of the screw is transmitted to the mold through the molten material. Combined with the short and thick inlet design of the mold, high-speed mold filling is achieved.

[0031] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the field.

Claims

1. A plug-type screw for plasticizing ultra-high molecular weight polyethylene, characterized in that: The material includes a material cylinder (1), a hopper (2), and a spraying assembly. The material cylinder (1) has a hollow structure and a material injection chamber (3) is provided on the material cylinder (1). A screw (4) is provided inside the material injection chamber (3). A flange (5) is connected to the material cylinder (1). The spraying assembly includes a nozzle (6) and a nozzle (7). The nozzle (6) and the nozzle (7) are matched with the flange (5). The nozzle (6) and the nozzle (7) are matched with the material injection chamber (3).

2. The plug-type screw for plasticizing ultra-high molecular weight polyethylene according to claim 1, characterized in that: The screw (4) is provided with a screw head (8), the screw head (8) is provided with a check ring (9), and the inner wall of the injection cavity (3) is provided with two sets of symmetrically arranged mediators (10), and both sets of mediators (10) are matched with the screw (4).

3. The injection-type screw for plasticizing ultra-high molecular weight polyethylene according to claim 1, characterized in that: The hopper (2) is equipped with a PLC system motor (11), and the output end of the PLC system motor (11) is connected to a stirring shaft (12). A set of combined fan blades is snapped into both sides of the stirring shaft (12). Both sets of combined fan blades include multiple inclined fan blade bodies, and the two sets of fan blade bodies are spaced apart.

4. The plug-type screw for plasticizing ultra-high molecular weight polyethylene according to claim 3, characterized in that: The fan blade body includes a first fan blade (13), the first fan blade (13) is provided with a sliding groove (14), the sliding groove (14) is provided with a sliding block (15), the sliding block (15) is slidably connected to the inner walls on both sides of the sliding groove (14), one end of the sliding block (15) is connected to a second fan blade (22), and the other end of the sliding block (15) is connected to the bottom wall of the sliding groove (14) through a first reset spring (16).

5. A plug-type screw for plasticizing ultra-high molecular weight polyethylene according to claim 4, characterized in that: The sliding block (15) has mounting grooves (17) on both sides of its sidewalls, and the openings of the two mounting grooves (17) face the inner walls of the two sides of the sliding groove (14). Mounting blocks (18) are slidably connected in both mounting grooves (17), and mounting rods (19) are fixedly connected to both mounting blocks (18). Buffer rollers (20) are rotatably connected to both mounting rods (19).

6. The plug-type screw for plasticizing ultra-high molecular weight polyethylene according to claim 5, characterized in that: The mounting block (18) has two symmetrically arranged second reset springs (21) engaged, and the second reset springs (21) are engaged with the bottom wall of the mounting groove (17). Both the first reset spring (16) and the second reset springs (21) are damping springs.

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