Combined screw for plastic extrusion

Abstract

The utility model relates to the technical field of plastic extrusion, in particular to a combined screw for plastic extrusion, which comprises a driving end, a main rod body integrally formed with the driving end and a shearing and mixing component, and the main rod body is sequentially provided with a feeding section close to the driving end, a compression section, a metering section and a mounting section far away from the driving end along the axial direction. The shearing and mixing assembly comprises a shearing block, a mixing block and a screw head which are sequentially arranged in the axial direction, and the shearing block, the mixing block and the screw head are detachably mounted on the mounting section; wherein the shearing block and the mixing block are both replaceable elements. According to the combined screw rod provided by the technical scheme, the plasticizing capacity of the combined screw rod can be adjusted by replacing different types of shearing blocks and mixing blocks, so that the requirements of different materials on plasticizing are met, and the use cost of the screw rod is reduced.

Description

Technical Field

[0001] This utility model relates to the field of plastic extrusion technology, and in particular to a screw for plastic extrusion. Background Technology

[0002] Plastic extrusion is an important plastic molding method. Its principle involves heating and melting plastic granules or powder using an extruder, and then extruding it through a specific die (such as a die) to form the desired continuous profile (such as pipes, rods, sheets, films, etc.). The extrusion molding process typically includes three stages: plasticizing, forming, and shaping. In the forming stage, the molten material is pushed through a die of a specific shape by the rotating screw of the extruder, transforming it into a continuous profile.

[0003] Currently, most screws used in plastic extrusion adopt a one-piece structure, which is directly machined from round steel bars. Once manufactured, the structural design of this type of screw cannot be changed. Therefore, the screw's plasticizing capacity is not adjustable, making it unable to adapt to diverse materials and formulations, resulting in high operating costs and failing to meet the demands of fierce market competition. Utility Model Content

[0004] In view of the technical problems existing in the traditional screws used for plastic extrusion, the purpose of this utility model is to provide a combined screw that can adapt to a variety of materials.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a combined screw for plastic extrusion, comprising a drive end, a main rod integrally formed with the drive end, and a shearing and mixing assembly. The main rod is provided axially with a feeding section, a compression section, a metering section near the drive end, and an mounting section away from the drive end. The shearing and mixing assembly includes a shearing block, a mixing block, and a screw head arranged axially. The shearing block, the mixing block, and the screw head are all detachably mounted on the mounting section. The shearing block and the mixing block are replaceable components.

[0006] In the above technical solution, preferably, the screw head is located away from the metering section, and the maximum outer diameter of the screw head is greater than the minimum inner diameter of the mixing block and the shearing block, so as to prevent the mixing block or the shearing block from detaching from the mounting section axially.

[0007] In the above preferred embodiment, more preferably, the mounting section is configured with a reverse-rotating external thread, and the screw head is formed with a reverse-rotating internal thread adapted to the reverse-rotating external thread.

[0008] In the preferred embodiment described above, it is further preferred that the mounting section is provided with a plurality of axially extending torque blocks, and the shear block and / or the mixing block are provided with a plurality of keyways adapted to the plurality of torque blocks.

[0009] In the above technical solution, preferably, the installation section is adjacent to the metering section, and the bottom diameter of the metering section is larger than the bottom diameter of the feeding section and the compression section.

[0010] In the above technical solution, preferably, the shearing block has a plurality of shearing teeth arranged at intervals and interlacing with each other.

[0011] In the above technical solution, preferably, the combined screw further includes a first screw ridge and a second screw ridge formed on the main shaft body, the first screw ridge extending from the end of the feeding section near the driving end to the end of the compression section away from the driving end, and the second screw ridge located on the metering section.

[0012] Compared to existing technologies, the combined screw provided by this utility model can adjust its plasticizing capacity by replacing different types of shear blocks and mixing blocks to meet the plasticizing requirements of different materials, thereby reducing the cost of using the screw. Attached Figure Description

[0013] Figure 1 This is a front view of the combined screw provided by this utility model;

[0014] Figure 2 for Figure 1 Partial half-planed view of the combined screw shown;

[0015] Figure 3 for Figure 1 The diagram shows the disassembly of the assembled screw.

[0016] The image is labeled as follows:

[0017] 100. Combined screw; Y. Axis centerline;

[0018] 1. Driver end;

[0019] 2. Main rod body; 21. Feeding section; 22. Compression section; 23. Metering section; 24. Installation section; 25. Torque block; 26. Reverse external thread;

[0020] 3. First spiral edge;

[0021] 4. Second spiral ridge;

[0022] 5. Shear block; 51. Shear tooth;

[0023] 6. Mixed blocks;

[0024] 7. Screw head. Detailed Implementation

[0025] To explain in detail the technical content, structural features, achieved objectives and effects of this application, the technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings.

[0026] In this application, spatial relative terms such as “below,” “under,” “below,” “down,” “above,” “above,” “higher,” and “side” (e.g., as in a “sidewall”) are used to describe the relationship between one element and another element as shown in the accompanying drawings. Spatial relative terms are intended to include different orientations of the device in use, operation, and / or manufacture other than those depicted in the drawings. For example, if the device in the drawings is flipped, an element described as “below” or “under” another element or feature would then be positioned “above” said other element or feature. Thus, the exemplary term “below” can include both above and below orientations. Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or in other orientations), thus interpreting the spatial relative descriptive terms used herein accordingly.

[0027] This invention provides a combined screw 100 for plastic extrusion, designed to adjust the screw's plasticizing capacity through replaceable shear-mixing components, making it adaptable to various materials. It should be noted that the following embodiments illustrate the technical solution provided by this invention using a single screw; however, it is understood that by providing replaceable and interoperable shear-mixing element pairs, the technical solution of this invention can undoubtedly be applied to twin-screw or multi-screw extrusions. Therefore, the specific type of screw does not limit the scope of protection of this invention.

[0028] like Figure 1 As shown, the combined screw 100 provided by this utility model defines an axis Y and has a drive end 1, a main rod body 2 integrally formed with the drive end 1, a first screw rib 3 and a second screw rib 4 formed on the main rod body 2, and a replaceable shearing and mixing assembly. The drive end 1 has a spline 11 formed for connection to a transmission structure to facilitate access to external power.

[0029] The main rod 2 extends along the axis Y and sequentially forms a feeding section 21 near the drive end 1, a compression section 22 and a metering section 23 away from the drive end 1. The first screw rib 3 extends from the end of the feeding section 21 near the drive end 1 to the end of the compression section 22 away from the drive end 1, and the second screw rib 4 is formed on the metering section 23.

[0030] The feeding section 21 receives the material and transports it to the compression section 22. The compression section 22 compacts, melts, and establishes extrusion pressure. In this compression section 22, the material gradually changes from a solid to a liquid state, and the screw channel volume decreases accordingly to accommodate the decrease in the material's geometric volume. The metering section 23 extrudes the molten material from the compression section 22 at a controlled temperature and quantity to the front end of the combined screw 100 to supply the die head for production needs. The bottom diameter of the metering section 23 is larger than that of the compression section 22 and the feeding section 21.

[0031] Combination Figure 2 and Figure 3 The shearing and mixing assembly includes a shearing block 5, a mixing block 6, and a screw head 7, which are detachably mounted sequentially along the axial direction on the main rod body 2. The shearing block 5 and the screw head 7 are respectively positioned close to and away from the metering section 23. The main rod body 2 has a mounting section 24 for detachable installation of the shearing block 5, the mixing block 6, and the screw head 7. The screw head 7 can lock the shearing block 5 and the mixing block 6 onto the main rod body 2, preventing them from detaching axially from the mounting section.

[0032] Furthermore, the installation section 24 is positioned close to the metering section 23. The metering section 23 has the largest bottom diameter on the main rod 2, which meets the strength requirements of the split structure, and the main rod 2 breaks at the connection point of the installation section 24.

[0033] The outer surface of the shear block 5 has interlocking shear teeth 51 with clearance fit. As the combined screw 100 rotates, the material is squeezed between the outer wall of the shear block 5 and the inner wall of the corresponding extruder barrel. During this process, multiple cavities with regularly changing volumes are formed between the shear teeth 51 and the inner wall of the barrel. The material is repeatedly sheared, expanded, and squeezed within these cavities, thereby accelerating and improving the plasticizing process and enhancing the plasticizing quality.

[0034] Mixing block 6 promotes mixing by generating shear forces within the material. As the material passes through mixing block 6, it is stretched, folded, and redistributed, resulting in a homogeneous mixture of different components. This mixing method is particularly important for processing high-viscosity materials or applications requiring precise control of mixing ratios.

[0035] The mounting section 24 is provided with a plurality of axially extending torque blocks 25, and both the shear block 5 and the mixing block 6 are provided with a plurality of keyways adapted to the aforementioned torque blocks 25. Thus, the shear block 5 and the mixing block 6 can be inserted into and detached from the mounting section 24 axially. In other embodiments, the shear block and / or the mixing block can also be connected to the mounting section by various methods such as plug-in structures, snap-fit ​​structures, and threaded connections, as long as it is ensured that the shear block and the mixing block form a detachable connection with the mounting section and can rotate together with the main rod.

[0036] The maximum outer diameter of the screw head 7 is greater than the minimum inner diameter of the mixing block 6 and the shearing block 5 to prevent the mixing block 6 or the shearing block 5 from detaching from the mounting section 24 axially. In this embodiment, the mounting section 24 is provided with a reverse-rotation external thread 26, and the screw head 7 is formed with a reverse-rotation internal thread adapted to the reverse-rotation external thread 26 (i.e., having a rotation direction opposite to the first and second threads) to ensure the reliability of the direct mechanical connection between the screw head 7 and the mounting section 24.

[0037] Compared with the prior art, the combined screw 100 provided by this utility model can adjust its plasticizing capacity by replacing different types of shearing blocks 5 and mixing blocks 6 to meet the plasticizing requirements of different materials, thereby reducing the cost of using the screw.

[0038] The above embodiments are only for illustrating the technical concept and features of this application, and are intended to enable those skilled in the art to understand the content of this application and implement it accordingly. They should not be construed as limiting the scope of protection of this application. All equivalent changes or modifications made in accordance with the spirit of this application should be included within the scope of protection of this application.

Claims

1. A combined screw for plastic extrusion, characterized in that, The device includes a drive end, a main rod integrally formed with the drive end, and a shearing and mixing assembly. The main rod has a feeding section, a compression section, a metering section, and an installation section away from the drive end arranged sequentially along the axial direction. The shearing and mixing assembly includes a shearing block, a mixing block, and a screw head arranged sequentially along the axial direction. The shearing block, the mixing block, and the screw head are all detachably mounted on the installation section. The shearing block and the mixing block are replaceable components.

2. The combined screw according to claim 1, characterized in that, The screw head is positioned away from the metering section, and the maximum outer diameter of the screw head is greater than the minimum inner diameter of the mixing block and the shearing block, in order to prevent the mixing block or the shearing block from detaching from the mounting section axially.

3. The combined screw according to claim 2, characterized in that, The mounting section is configured with a reverse-rotating external thread, and the screw head is formed with a reverse-rotating internal thread adapted to the reverse-rotating external thread.

4. The combined screw according to claim 2, characterized in that, The mounting section is provided with a plurality of axially extending torque blocks, and the shear block and / or the mixing block are provided with a plurality of keyways adapted to the plurality of torque blocks.

5. The combined screw according to claim 1, characterized in that, The installation section is adjacent to the metering section, and the bottom diameter of the metering section is larger than the bottom diameter of the feeding section and the compression section.

6. The combined screw according to claim 1, characterized in that, The shearing block has a number of shearing teeth arranged at intervals and intersecting each other.

7. The combined screw according to claim 1, characterized in that, It also includes a first screw ridge and a second screw ridge formed on the main rod body, wherein the first screw ridge extends from the end of the feeding section near the drive end to the end of the compression section away from the drive end, and the second screw ridge is located on the metering section.

Images