Single-screw pulsating extrusion device with self-cleaning function and self-meshing extrusion equipment

Abstract

The invention provides a single-screw pulse extrusion device with a self-cleaning function and self-meshing extrusion equipment. The extrusion device comprises a screw and a machine barrel, the screw rod is arranged in the machine barrel in a penetrating mode, the screw rod is meshed with the machine barrel, the cross section of the screw rod is in a reuleaux triangle shape, the molded line of the end face of the machine barrel is a fillet square hole formed by rotation of the reuleaux triangle, and the square hole reversely sweeps in the machine barrel in the axial direction to form a screw groove; in the machine barrel, the materials generate periodic volume change along with rotation of the screw rod, and the materials are pushed to move; in the operation process of the screw rod, compression and expansion circulation of materials is achieved, through the pulsation extrusion effect, the melting, mixing and exhausting efficiency is improved, and the melting, plasticizing and mixing effects of the materials are improved; meanwhile, efficient meshing of the inner surface of the screw and the inner wall of the runner is ensured, and the self-cleaning effect is achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of screws, and in particular to a single-screw pulsating extruder device and a self-meshing extruder device with a self-cleaning function. Background Art

[0002] The single screw mechanism is a commonly used extrusion mechanism with the advantages of simple structure, easy operation and maintenance, and the ability to establish a stable extrusion pressure. Therefore, it has been widely used. The application scope of the single screw mechanism has been extended to the fields of filling, blending and reactive extrusion of various materials. Based on the high requirements for melt mixing efficiency, the commonly used ones are pin screws, corrugated screws, cavitation transfer mixers, separation screws, etc., but the current types of screws have different degrees of poor adaptability to different material systems and screw speeds, lack of adaptive mechanism of the melting process, and even cause materials to block the screw groove. On the other hand, the current single screw extruder relies on the friction conveying mechanism, the inner surface of the screw cannot achieve the self-cleaning function, lacks positive displacement conveying capacity, the extruder output is greatly affected by the die resistance, and the screw extrusion characteristics are relatively soft. Summary of the invention

[0003] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0004] The purpose of the present application is to solve at least one of the technical problems existing in the related art to a certain extent. The embodiments of the present application provide a single-screw pulsating extruder and a self-meshing extruder with a self-cleaning function, which can improve mixing, improve melting, mixing and exhaust efficiency, and improve the melting, plasticizing and mixing effects of materials.

[0005] An embodiment of the first aspect of the present application is a single-screw pulsating extruder with a self-cleaning function, comprising a screw and a barrel; the screw is inserted into the barrel, the screw is meshed with the barrel, the cross-section of the screw is a Reuleaux triangle, the profile of the end face of the barrel is a square hole with rounded corners formed by rotating the Reuleaux triangle, and the square hole is axially swept in the reverse direction to form a screw groove inside the barrel.

[0006] According to an embodiment of the first aspect of the present application, the center of mass of the screw revolves around the origin of the rectangular coordinate system on an arc of an ellipse.

[0007] According to an embodiment of the first aspect of the present application, the side length of the square hole is defined as a, and the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle is α; the coordinates of the vertex of the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle are (L, a / 2), where L=cosα-a / 2; the parametric equation of the arc of the centroid in the first quadrant of the rectangular coordinate system is:

[0008] According to an embodiment of the first aspect of the present application, the parametric equation of the arc of the centroid point in the second quadrant of the rectangular coordinate system is:

[0009] According to an embodiment of the first aspect of the present application, the parametric equation of the arc of the centroid point in the third quadrant of the rectangular coordinate system is:

[0010] According to an embodiment of the first aspect of the present application, the parametric equation of the arc of the centroid in the fourth quadrant of the rectangular coordinate system is:

[0011] According to an embodiment of the first aspect of the present application, the range of the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle is: 30°≤α≤60°.

[0012] According to an embodiment of the first aspect of the present application, the barrel is square.

[0013] An embodiment of the second aspect of the present application is a self-meshing extrusion device, which is provided with a single-screw pulsating extruder device with a self-cleaning function as described in the embodiment of the first aspect of the present application.

[0014] The above scheme has at least the following beneficial effects: in the barrel, the material undergoes periodic volume changes as the screw rotates, driving the material to move; during the operation of the screw, a compression and expansion cycle of the material is achieved, and through the pulsating extrusion effect, the melting, mixing and exhaust efficiency are improved, thereby improving the melting, plasticizing and mixing effects of the material; at the same time, efficient meshing between the inner surface of the screw and the inner wall of the flow channel is ensured to achieve a self-cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0016] Figure 1 is a structural diagram of a single-screw pulsating extruder provided in an embodiment of the present application;

[0017] Figure 2 Schematic diagram of the meshing state of the single-screw pulsation extruder provided in the embodiment of the present application;

[0018] Figure 3 is a front view of a single-screw pulsating extruder provided in an embodiment of the present application;

[0019] Figure 4 is a structural diagram of a screw of a single-screw pulsating extruder provided in an embodiment of the present application;

[0020] Figure 5 It is a front view of the screw of the single-screw pulsation extruder provided in an embodiment of the present application;

[0021] Figure 6 is a right side view of the screw of the single-screw pulsation extruder provided in an embodiment of the present application;

[0022] Figure 7 It is a front view of the barrel of the single-screw pulsation extruder provided in the embodiment of the present application;

[0023] Figure 8 1 is a schematic diagram of the barrel axis side of a single-screw pulsating extruder provided in an embodiment of the present application;

[0024] Fig. 9 is a locus diagram of the center motion of the Leroy triangle of the single-screw pulsating extruder provided in the embodiment of the present application;

[0025] Fig.10 It is a front cross-sectional view of a single screw pulsating extruder at different times when the center of the screw's Leroy triangle orbits for one cycle;

[0026] Fig.11 It is a cross-sectional diagram of the midpoint of the length of the screw element at different times when the center of the screw's Reault triangle orbits for one cycle;

[0027] Fig.12 It is a right-side cross-sectional view of the melting section of a single-screw pulsating extruder at different times when the center of the screw's Lelo triangle revolves for one cycle. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] It should be noted that, although the functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first", "second", etc. in the specification, claims or the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0030] At present, all types of screws have different degrees of poor adaptability to different material systems and screw speeds, lack of adaptive mechanism in the melting process, and even cause materials to block the screw groove. On the other hand, the current single-screw extruder relies on the friction conveying mechanism, the inner surface of the screw cannot achieve self-cleaning function, lacks positive displacement conveying capacity, the output of the extruder is greatly affected by the die resistance, and the screw extrusion characteristics are relatively soft.

[0031] In order to solve the above problems, an embodiment of the present application provides a single-screw pulsating extruder with a self-cleaning function.

[0032] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0033] Reference Figures 1 to 8 The single screw pulsating extruder comprises a screw 200 and a barrel 100. The screw 200 is inserted into the barrel 100, the screw 200 is meshed with the barrel 100, the cross section of the screw 200 is a Reuleaux triangle, the profile of the end face of the barrel 100 is a square hole with rounded corners formed by rotating the Reuleaux triangle, and the square hole is reversely swept in the axial direction to form a screw groove inside the barrel 100.

[0034] In the barrel 100, the material undergoes periodic volume changes as the screw 200 rotates, driving the material to move. During the operation of the screw 200, a compression and expansion cycle of the material is achieved, and through the pulsating extrusion effect, the melting, mixing and exhaust efficiency are improved, thereby improving the melting, plasticizing and mixing effects of the material. At the same time, efficient meshing between the inner surface of the screw 200 and the inner wall of the flow channel 300 is ensured to achieve a self-cleaning effect.

[0035] The center of mass of the screw 200 revolves around the origin of the rectangular coordinate system on the arc of an ellipse. It is understandable that the arc can also be approximately elliptical.

[0036] A plane rectangular coordinate system is established for the single screw pulsating extruder, and a plane rectangular coordinate system is established in the cross section of the single screw pulsating extruder. In the plane rectangular coordinate system, the origin is set as O, the horizontal axis is the X axis, and the vertical axis is the Y axis.

[0037] Define the side length of the square hole as a, the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle as α; the vertex of the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle is vertex 1, and the coordinates of vertex 1 are (L, a / 2), where L = 1R-a / 2, 1R = cosα. R is one end of the side of the square hole where vertex 1 is located.

[0038] The angle α changes from 60° to 30° with the rotation. At this time, draw a vertical line A′B′ through the center point, and let the intersection of the vertical line and the side of the square hole be N, then we have ∠31R=α,∠31P=30°. It can be further concluded that ∠R1P=30°+α,1R=cosα.

[0039] Rounding radius

[0040] The parametric equation of the arc whose centroid is in the first quadrant of the rectangular coordinate system is:

[0041] According to an embodiment of the first aspect of the present application, the parametric equation of the arc of the centroid in the second quadrant of the rectangular coordinate system is:

[0042]

[0043] According to an embodiment of the first aspect of the present application, the parametric equation of the arc whose centroid is in the third quadrant of the rectangular coordinate system is: According to an embodiment of the first aspect of the present application, the parametric equation of the arc whose centroid is in the fourth quadrant of the rectangular coordinate system is:

[0044]

[0045] Reference Figure 2 Along the axial direction of the screw 200, the barrel 100 is sequentially provided with a sealing section 110, a conveying section 120, a melting section 130, and a mixing and extruding section 140, so that the material can enter the conveying section 120, and then the single screw 200 drives the material to be conveyed, so that the material can enter the melting section 130, so that the material can be melted, and the materials can be mixed together, and the materials can enter the mixing and extruding section 140, so that the materials can be discharged from the discharge port, thereby enhancing the melting, mixing and exhaust efficiency.

[0046] Reference Figures 4 to 6 The screw 200 of the single-screw pulsating extruder is characterized in that the end face and each cross section of the screw 200 are all Reuleaux triangles, and the compression ratios of the screw 200 of the sealing section 110, the melting section 130, the conveying section 120, and the mixing and extrusion section 140 are different to form different lengths.

[0047] Reference Figure 7 and Figure 8 The barrel 100 of the single screw pulsating extruder is characterized in that the inner wall of the barrel 100 is composed of screw grooves of different proportions, and the screw grooves are a combination of rounded square holes at different positions of the rotation trajectory of the single screw 200.

[0048] The trajectory of the centroid of the single screw 200 around the origin of the coordinates is approximately an arc segment of an ellipse. As the screw 200 rotates, the volume enclosed by the screw 200 and the barrel 100 changes periodically, so that the material is continuously squeezed and stretched in the screw groove, the stretching effect of the side gap area of ​​the meshing part of the screw 200 and the barrel 100 is enhanced, and the shearing effect at the gap between the head of the screw 200 and the inner wall of the barrel 100 is enhanced, accelerating the melting, plasticizing and mixing of the material, thereby shortening the production cycle and saving energy. In addition, by setting the screw 200 as a single root, the single screw pulsating extruder has the advantage of high output, and can improve the efficiency of plasticization and mixing ability, maintain the self-cleaning function, and improve the processing efficiency of the material. The shape of the screw 200 and the barrel 100 is simple, the processing and manufacturing cost is reduced, and the production efficiency of the single screw 200 extruder can be improved, and the processing quality of the material can be improved.

[0049] Reference Fig. 9 When the center of mass of the screw 200 revolves around the axis of the barrel 100 along a trajectory, the center of mass and the top of the screw 200 rotate at different speeds, forming a geometric relationship between the screw 200 and the square hole.

[0050] Reference Figures 10 to 12 , when the screw 200 revolves around the trajectory at the center of mass, the center of mass and the top of the screw 200 rotate at different speeds. The Lelo triangle screw 200 and the square groove with rounded corners in the mating meshing cross section form an extrusion cavity, and the material flow space changes periodically. As the screw 200 rotates, the volume enclosed by the screw 200 and the barrel 100 changes periodically. When the material enters the screw 200, the material changes in volume periodically under the interaction between the single screw 200 and the barrel 100, increasing and decreasing. During the conveying process, the material is conveyed from one screw groove to the next adjacent screw groove, and the material frequently rolls, folds and reorganizes between the screws 200, which significantly enhances the mutual penetration and contact area between the materials. This periodic interface renovation and enhancement effect fundamentally breaks the stable laminar flow or local stagnation phenomenon caused by the material in the traditional single screw 200 extruder, accelerates the melting, plasticization and mixing of the material, thereby shortening the production cycle and saving energy.

[0051] The material processing method uses a single-screw pulsating extruder.

[0052] The processing method includes but is not limited to the following steps:

[0053] Step S100, adding materials;

[0054] Step S200, the single screw 200 rotates in the screw groove of the barrel 100 and changes periodically with time. The screw 200 cooperates with the barrel 100 to transport the material.

[0055] In step S300, the material is melted by external heating and the heat generated by the rotation of the screw 200 relative to the barrel 100, so that the material forms a melt.

[0056] Step S400: The barrel 100 and the single screw 200 cooperate to extrude and stretch the material, and drive the material to be extruded and formed from the material outlet.

[0057] In the single-screw pulsating extruder, the material is introduced into the barrel 100, and the screw 200 begins to rotate in the direction of the thread. The rotation of the screw 200 causes periodic volume changes in the screw groove in the barrel 100, thereby effectively pushing the material along the flow channel 300. The sealing section 110 of the screw 200 is designed as a small lead thread structure to prevent material leakage, while the conveying section 120 has a large volume to achieve positive displacement pushing of the material during the extrusion process. The external heating element and the extrusion friction heat generated during the rotation of the screw 200 work together to accelerate melting under the periodic extrusion formed by the screw 200 and the inner surface of the barrel 100, so that the material is heated to a molten state in the barrel 100, forming a melt that can be extruded and stretched in the flow channel 300. This process significantly enhances the dispersion and mixing effect of the material. The flow channel 300 is designed as a spiral groove formed by a square hole with rounded corners sweeping in the opposite direction along the axial direction, and keeps meshing with the running screw 200, thereby forming a periodically changing conveying space, introducing extrusion and pulsation disturbance effects, which further improves the mixing efficiency of the materials. This structure ensures efficient meshing between the screw 200 and the flow channel 300, and promotes the realization of the self-cleaning effect through the superposition of periodic pulsations.

[0058] It should be noted that the external heating element can be a heating mechanism such as an electric heating wire or an electric heating coil, which is convenient for heating the material to melt the material.

[0059] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the embodiments. Technical personnel familiar with the field can make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A single screw pulsating extruder with self-cleaning function, characterized in that: It includes a screw and a barrel; the screw is inserted into the barrel, the screw is meshed with the barrel, the cross section of the screw is a Reuleaux triangle, the profile of the end face of the barrel is a square hole with rounded corners formed by rotating the Reuleaux triangle, and the square hole is axially reversely swept inside the barrel to form a screw groove.

2. The single-screw pulsating extruder with self-cleaning function according to claim 1, characterized in that: The center of mass of the screw revolves around the origin of the rectangular coordinate system on the arc of the ellipse.

3. The single-screw pulsating extruder with self-cleaning function according to claim 2, characterized in that: The side length of the square hole is defined as a, and the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle is defined as α; the vertex of the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle is defined as (L, a / 2), where L=cosα-a / 2; the parametric equation of the arc of the centroid in the first quadrant of the rectangular coordinate system is:

4. The single-screw pulsating extruder with self-cleaning function according to claim 2, characterized in that: The parametric equation of the arc of the centroid point in the second quadrant of the rectangular coordinate system is:

5. The single-screw pulsating extruder with self-cleaning function according to claim 2, characterized in that: The centroid The parametric equation of the arc whose point is in the third quadrant of the rectangular coordinate system is:

6. The single-screw pulsating extruder with self-cleaning function according to claim 2, characterized in that: The centroid The parametric equation of the arc whose point is in the fourth quadrant of the rectangular coordinate system is:

7. The single-screw pulsating extruder with self-cleaning function according to claim 2, characterized in that: The range of the angle between the side of the square hole and the side of the equilateral triangle in the Reuleaux triangle is: 30°≤α≤60°.

8. The single-screw pulsating extruder with self-cleaning function according to claim 1, characterized in that: The barrel is square.

9. A self-engaging extrusion device, characterized in that: A single-screw pulsating extruder with a self-cleaning function as described in any one of claims 1 to 8 is provided.

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