Double-screw extrusion device for sheet production line

Abstract

The utility model discloses a double-screw extrusion device for a sheet production line. The double-screw extrusion device comprises a rack, a double-screw machine barrel, a pair of extrusion screws, a driving assembly and a confluence core, each extrusion screw comprises a core shaft, a plurality of thread elements and a plurality of shearing blocks, the core shafts are coaxially sleeved with the thread elements, and the thread elements and the shearing blocks synchronously rotate with the core shafts; the extrusion screw sequentially comprises a feeding section, a conveying section, a plasticizing section, an exhaust section and a pressure building section from front to back, and the length of the plasticizing section is larger than that of other sections; the plasticizing section is divided into a first plasticizing section, an exhaust section and a second plasticizing section from front to back, in the plasticizing section, the shearing blocks connected front and back form shearing parts in the circumferential direction of the core shaft, the threaded elements connected front and back form threaded parts in the circumferential direction of the core shaft, and the shearing parts and the threaded parts are alternately distributed from front to back; the total length of the shearing part of the first plasticizing section is greater than that of the shearing part of the second plasticizing section; materials are fully plasticized, the detachable screw rod structure facilitates replacement of local abrasion parts, and the production cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of sheet material production equipment, and in particular to a twin-screw extruder for a sheet material production line. Background Art

[0002] In sheet production, some sheets need to add a large amount of glass fiber, ceramics, resin, nylon and other additives to improve performance according to production requirements. In the past, extrusion screws were easily worn when processing such additives, and the plasticization of additives and materials was insufficient. Extrusion screws that were often worn needed to be replaced frequently, which was difficult to disassemble and assemble, and the cost of screw replacement was high. Materials with poor plasticization effects resulted in poor quality of the melt extruded by the extruder, and the final product did not meet production requirements. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present application is to provide a twin-screw extruder for a sheet production line.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: a twin-screw extruder device for a sheet production line, comprising a frame, a twin-screw barrel installed on the frame, a pair of extrusion screws rotatably arranged in the twin-screw barrel, a driving assembly for driving the pair of extrusion screws to rotate, and a confluence core installed at the extrusion port of the twin-screw barrel, the pair of extrusion screws are symmetrically arranged and meshed with each other, each of the extrusion screws comprises a core shaft and a plurality of threaded elements and a plurality of shearing blocks coaxially sleeved on the core shaft and rotating synchronously with the core shaft; each of the shearing blocks comprises a plurality of shearing pieces arranged in sequence from front to back, each of the shearing pieces has at least two convex portions protruding radially outward, and the convex portions on each of the shearing blocks are arranged in a spiral direction from front to back; the extrusion screws are sequentially joined from front to back. The material section, conveying section, plasticizing section, exhaust section and pressure building section, the length of the plasticizing section is greater than the lengths of other sections; the plasticizing section is divided into a first plasticizing section, an exhaust section and a second plasticizing section from front to back, the exhaust section is composed of a plurality of the threaded elements and at least a part of the mandrel connected in sequence from front to back, the first plasticizing section and the second plasticizing section are respectively composed of a plurality of the threaded elements, a plurality of the shearing blocks and at least a part of the mandrel; in the plasticizing section, the shearing blocks connected front and back form a shearing portion in the circumferential direction of the mandrel, the threaded elements connected front and back form a threaded portion in the circumferential direction of the mandrel, the shearing portions and the threaded portions are alternately distributed from front to back, and the total length of the shearing portion of the first plasticizing section is greater than the total length of the shearing portion of the second plasticizing section.

[0005] In the above technical solution, it is further preferred that each of the threaded elements and each of the shear blocks are connected to the core shaft key.

[0006] In the above technical solution, it is further preferred that the feeding section, conveying section, exhaust section and pressure building section are respectively composed of a plurality of the threaded elements and at least part of the core shaft.

[0007] In the above technical solution, it is further preferred that the several threaded elements all have double threads, the double threads of the connected threaded elements respectively form a continuous main thread and auxiliary thread, and the main thread and the auxiliary thread are arranged alternately from front to back.

[0008] In the above technical scheme, it is further preferred that the lead of the secondary thread of each of the threaded elements is equal to the lead of the main thread, the lead of the main thread of the feeding section is greater than or equal to the lead of the main thread of the conveying section, the lead of the main thread of the exhaust section is smaller than the lead of the main thread of the feeding section and greater than the lead of the main thread of the pressure building section, the lead of the main thread of the exhaust section is equal to the lead of the main thread of the exhaust section, and the lead of the main thread of the first plasticizing section and the lead of the main thread of the second plasticizing section are both smaller than the lead of the main thread of the exhaust section.

[0009] In the above technical solution, it is further preferred that the lead of the main thread of the first half of the conveying section is greater than the lead of the main thread of the second half of the conveying section, and is equal to the lead of the main thread of the feeding section; the lead of the main thread of the first half of the pressure building section is greater than the lead of the main thread of the second half of the pressure building section.

[0010] In the above technical solution, it is further preferred that the aspect ratio of the extrusion screw is 40-48.

[0011] In the above technical solution, it is further preferred that the twin-screw barrel is provided with a first exhaust port and a second exhaust port, the position of the first exhaust port corresponds to the position of the exhaust section, the position of the second exhaust port corresponds to the position of the exhaust section, and the second exhaust port is connected to a vacuum system.

[0012] In the above technical solution, it is further preferred that the twin-screw barrel is divided into several areas from front to back, each of the areas is equipped with a temperature control module, and each of the temperature control modules is used to adjust the temperature of each of the areas.

[0013] In the above technical solution, it is further preferred that the driving assembly includes a DC motor and a gear box, the gear box is connected to the DC motor through a safety coupling, the safety coupling is equipped with a sensor, and the sensor is connected to the DC motor signal.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The extrusion screw of the present application can fully plasticize materials with high wear resistance and high rigidity, thereby improving the plasticization effect and the quality of the final product; the detachable screw structure facilitates the replacement of locally worn parts and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a twin-screw extruder provided in an embodiment of the present application;

[0017] Figure 2 for Figure 1 A top view of a twin-screw extruder in FIG.

[0018] Figure 3 for Figure 1 A schematic diagram of the structure of an extrusion screw of a twin-screw extruder in FIG.

[0019] Figure 4 for Figure 3 A schematic diagram of the structure of the feeding section in FIG.

[0020] Figure 5 for Figure 3 A schematic diagram of the structure of the conveying section in FIG.

[0021] Figure 6 for Figure 3 The structural schematic diagram of the plasticizing section in FIG.

[0022] Figure 7 For along Figure 6 The cross-sectional view cut along the AA line in the figure;

[0023] Figure 8 for Figure 3 A schematic diagram of the structure of the exhaust section;

[0024] Fig. 9 for Figure 3 Schematic diagram of the structure of the pressure building section.

[0025] Wherein: 100, twin-screw extruder; 10, frame; 20, twin-screw barrel; 51, feed port; 52, discharge port; 53, first exhaust port; 54, second exhaust port; 6, temperature control module; 61, heater; 62, cooling jacket; 63, cooling oil tank; 30, extrusion screw; 1, mandrel; 2, thread element; 21, main thread; 22, secondary thread; 3, shear block; 31, shear piece; 311, convex part; 41, feeding section; 42, conveying section; 43, plasticizing section; 431, first plasticizing subsection; 432, exhaust subsection; 433, second plasticizing subsection; 44, exhaust section; 45, pressure building section; 40, drive assembly; 7, DC motor; 8, gear box; 9, safety coupling; 50, confluence core; 60, feeder. DETAILED DESCRIPTION

[0026] To describe the technical content, structural features, achieved purpose and effect of the application in detail, the technical solutions in the embodiments of the application will be described below in conjunction with the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all of the embodiments. In the following description, for the purpose of explanation, many specific details are set forth to provide a detailed description of various exemplary embodiments or implementations of the invention. However, various exemplary embodiments may also be implemented without these specific details or in the case of one or more equivalent arrangements. In addition, various exemplary embodiments may be different, but not necessarily exclusive. For example, without departing from the inventive concept, the specific shape, structure and characteristics of the exemplary embodiment may be used or implemented in another exemplary embodiment.

[0027] In the description of the present application, unless otherwise specified, “plurality” means two or more.

[0028] The “front” and “back” mentioned in this application are as follows: Figure 3 Before and after shown.

[0029] In the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0030] The present application embodiment provides a twin-screw extruder for a sheet production line, such as Figure 1 , 2 As shown, the twin-screw extruder 100 includes a frame 10, a twin-screw barrel 20 installed on the frame 10, a pair of extrusion screws (not shown in the figure) rotatably arranged in the twin-screw barrel 20, a driving assembly 40 for driving the pair of extrusion screws to rotate, and a confluence core 50 installed on the twin-screw barrel 20.

[0031] A pair of extrusion screws are symmetrically arranged and meshed with each other. The aspect ratio of the extrusion screws is 40-48. The longer screws allow the material to be fully plasticized and can improve the material conveying efficiency, thereby effectively increasing the extrusion output.

[0032] like Figure 3 As shown, each extrusion screw 30 includes a core shaft 1, a plurality of threaded elements 2 and a plurality of shear blocks 3, wherein the plurality of threaded elements 2 and the plurality of shear blocks 3 are sleeved on the core shaft 1, and each threaded element 2 and each shear block 3 are provided with an inner hole for the core shaft 1 to pass through, and an involute internal spline is provided in the inner hole along the axial direction of the core shaft 1, and a spline matching the involute internal spline is provided on the surface of the core shaft 1, so that the threaded element 2 and the shear block 3 arranged around the core shaft 1 can rotate around the axis of the core shaft 1 along with the core shaft 1. The threaded element 2 and the shear block 3 are detachably arranged on the core shaft 1, and when any threaded element 2 or the shear block 3 is worn, only a single element needs to be replaced, which is convenient for maintenance and reduces production costs.

[0033] like Figure 3 , 4 As shown, the threaded elements 2 are all double-threaded elements, and the surface has double threads extending spirally. The double threads of the threaded elements 2 connected front and back form a continuous main thread 21 and secondary thread 22, and the main thread 21 and the secondary thread 22 are arranged alternately from front to back; and the lead of the secondary thread 22 on each threaded element 2 is equal to the lead of the main thread 21.

[0034] like Figure 6 , 7 As shown, each shear block 3 includes a plurality of shearing pieces 31 arranged in sequence from front to back, each shearing piece 31 has at least two convex parts 311 protruding radially outward, and the convex parts 311 on each shearing block 3 are arranged in a spiral direction from front to back; the uneven surface of the shearing block 3 violently shears the material in the twin-screw barrel 20, effectively improving the plasticizing effect. The shearing block 3 cooperates with the threaded element 2 to stir the material evenly and improve the plasticizing effect and efficiency of the material.

[0035] like Figure 3 As shown, the extrusion screw 30 is composed of a feeding section 41, a conveying section 42, a plasticizing section 43, an exhaust section 44 and a pressure building section 45 from front to back. The length of the plasticizing section 43 is greater than the lengths of other sections, so that the extrusion screw 30 can fully plasticize the material, improve the plasticizing effect and the quality of the material extruded by the twin-screw extruder 100, and effectively improve the quality of the final product.

[0036] The feeding section 41 , the conveying section 42 , the exhaust section 44 and the pressure building section 45 are respectively composed of a plurality of threaded elements 2 and at least a portion of the core shaft 1 , and the plasticizing section 43 is composed of a plurality of threaded elements 2 , a plurality of shear blocks 3 and at least a portion of the core shaft 1 .

[0037] like Figure 4 As shown, the multiple threaded elements 2 connected in the front-to-back direction of the feeding section 41 form a continuous main thread 21 and a secondary thread 22 for forward conveying and stirring the material entering the twin-screw barrel 20 .

[0038] like Figure 5 As shown, the plurality of threaded elements 2 connected in the front-to-back direction of the conveying section 42 form a continuous main thread 21 and a secondary thread 22, and the lead S of the main thread 21 in the front half of the conveying section 42 is 21 The lead S1 of the main thread 21 of the feeding section 41 is equal to the lead S2 of the main thread 21 of the second half of the conveying section 42. 22 The lead S1 of the main thread 21 is smaller than that of the feeding section 41 , so that the material is forwardly conveyed to the plasticizing section 43 after being compressed and compacted in the conveying section 42 , thereby increasing the material intake of the extrusion screw 30 and the material conveying efficiency.

[0039] like Figure 6 As shown, in the plasticizing section 43, the front-to-back connected shear blocks 3 form a shearing portion in the circumferential direction of the core shaft 1, and the front-to-back connected threaded elements 2 form a threaded portion in the circumferential direction of the core shaft 1. The shearing portion and the threaded portion are alternately distributed from front to back. The material is sheared in the shearing portion, and is heated and plasticized under the severe shear force. It is evenly stirred in the threaded portion and transported to the downstream. The alternating distribution of the shearing portion and the threaded portion allows the material to be evenly stirred and fully plasticized, and avoids excessive plasticization caused by excessive shearing.

[0040] The plasticizing section 43 is divided into a first plasticizing section 431, an exhaust section 432 and a second plasticizing section 433 from front to back. The first plasticizing section 431 is composed of a plurality of threaded elements 2, a plurality of shear blocks 3 and a partial core shaft 1. The exhaust section 432 is composed of a plurality of threaded elements 2 and a partial core shaft 1 which are connected in sequence from front to back. The second plasticizing section 433 is composed of a plurality of threaded elements 2, a plurality of shear blocks 3 and a partial core shaft 1. The material passes through the alternately arranged shearing parts and threaded parts in the first plasticizing section 431 for preliminary plasticization, is forwardly transported under the continuous threads of the exhaust section 432, and releases part of the air carried by the feeding section 41. Finally, the material passes through the alternately arranged shearing parts and threaded parts in the second plasticizing section 433, and is fully plasticized before being transported to the downstream exhaust section 44. Among them, the total length of the shearing portion of the first plasticizing segment 431 is greater than the total length of the shearing portion of the second plasticizing segment 433, and the shearing portion of the second plasticizing segment 433 for shearing the material is shorter than the first plasticizing segment 431. On the one hand, the material that is not completely plasticized is sheared again to fully plasticize and melt the material, and on the other hand, the shearing force on the material is reduced to avoid the material from being overheated and over-plasticized in the second plasticizing segment 433. The exhaust segment 432 stirs the incompletely plasticized material between the first plasticizing segment 431 and the second plasticizing segment 433 to facilitate the second plasticizing segment 433 to fully plasticize the material. The lead S3 of the main thread of the exhaust segment 432 is greater than the lead of the main thread of the first plasticizing segment 431 and the second plasticizing segment 433, thereby releasing the air carried by the material from the feed port of the twin-screw barrel 20 during the rotation process.

[0041] like Figure 8 As shown, the multiple threaded elements 2 connected along the front-to-back direction of the exhaust section 44 form a continuous main thread 21 and a secondary thread 22, and the lead S4 of the main thread of the exhaust section 44 is smaller than the lead S1 of the main thread of the feeding section 41, and is equal to the lead S3 of the main thread of the exhaust section 432; the fully plasticized material will release a large amount of air and dust impurities, if not eliminated, bubbles and white spots will be generated in the molded film product, affecting the transparency and quality of the film product; the exhaust section 44 stirs the fully plasticized material so that the air and dust impurities in the material are released from the material.

[0042] like Fig. 9 As shown, the plurality of threaded elements 2 connected in the front-to-back direction of the pressure-building section 45 form a continuous main thread 21 and a secondary thread 22, and the lead S of the main thread of the front half of the pressure-building section 45 is 51 Greater than the lead S of the main thread of the second half of the pressure building section 45 52 , and are both smaller than the lead S4 of the main thread of the exhaust section 44. The material is compressed from front to back in the pressure building section 45 to establish a stable extrusion pressure, thereby improving the extrusion efficiency and extrusion stability.

[0043] like Figure 1, 2 As shown, the twin-screw barrel 20 has a feed port 51 for material entry, a discharge port 52 for material extrusion, and a first exhaust port 53 and a second exhaust port 54 arranged between the feed port 51 and the discharge port 52. The position of the feed port 51 corresponds to the position of the feeding section 41. A feeder 60 is provided at the feed port 51. The feeder 60 controls the flow rate of the material entering the feed port 51 to achieve continuous and uniform feeding and improve the feeding efficiency. After the material enters the feeding section 41 from the feed port 51, it is forwardly transported. The discharge port 52 is located at the end of the extrusion screw 30, and the confluence core 50 is installed at the discharge port 52. The discharge port 52 is for the material that has been completely plasticized by a pair of extrusion screws 30 to be output to the confluence core 50, and then the confluence through the confluence core 50 is transported to the downstream extrusion die. The position of the first exhaust port 53 corresponds to the position of the exhaust section 432, and the first exhaust port 53 is used for the gas released by the material in the exhaust section 432 to be discharged from the twin-screw extruder 100; the second exhaust port 54 is connected to a vacuum system (not shown in the figure), and the vacuum system loads negative pressure at the second exhaust port 54 to extract a large amount of air and dust impurities released by the material in the exhaust section 44 out of the twin-screw barrel 20.

[0044] The twin-screw barrel 20 is divided into several areas from front to back, and each area is equipped with a temperature control module 6. The temperature control module 6 includes a temperature sensor (not shown in the figure) arranged in the corresponding area, a heater 61 and a cooling jacket 62 sleeved on the twin-screw barrel 20. The heater 61 is used to heat the corresponding area. The cooling jacket 62 has a cooling channel arranged in the circumference of the twin-screw barrel 20. The cooling channel of each cooling jacket 62 is connected with a cooling oil tank 63. The cooling oil tank 63 is used to provide heat transfer oil to the cooling channel of each cooling jacket 62. The heat transfer oil enters the cooling channel to cool the corresponding area. A control valve is provided at the inlet of the cooling channel. The heater 61, the control valve and the temperature sensor are all connected to a controller signal. The controller controls the operation of the corresponding heater 61 and the control valve based on the detection results of each temperature sensor, realizes zoned temperature control of the twin-screw barrel 20, and ensures that the temperature of each area is constant.

[0045] The driving assembly 40 includes a DC motor 7 and a gear box 8, and the gear box 8 is connected to the DC motor 7 through a safety coupling 9. The coordinated use of the DC motor 7 and the gear box 8 can effectively reduce energy consumption, accurately control the speed and torque during production, and thus improve the extrusion output and extrusion efficiency. The safety coupling 9 is equipped with a sensor, and the sensor is connected to the DC motor 7 signal. When the extrusion screw 30 is stuck, the sensor transmits a signal to the DC motor 7 to stop the DC motor 7, which can protect the DC motor 7 and the gear box 8 and prevent the DC motor 7 from being overloaded and damaged.

[0046] The extrusion screw of the present application can fully plasticize materials with high wear resistance and high rigidity, thereby improving the plasticization effect and the quality of the final product; the detachable screw structure facilitates the replacement of locally worn parts and reduces production costs.

[0047] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present application. Without departing from the spirit and scope of the present application, the present application may have various changes and improvements, and the scope of protection required by the present application is defined by the attached claims, description and their equivalents.

Claims

1. A twin-screw extruder for a sheet production line, comprising a frame, a twin-screw barrel mounted on the frame, a pair of extrusion screws rotatably arranged in the twin-screw barrel, a driving assembly for driving the pair of extrusion screws to rotate, and a converging core mounted at the extrusion port of the twin-screw barrel, wherein the pair of extrusion screws are symmetrically arranged and meshed with each other, characterized in that: Each of the extrusion screws comprises a core shaft and a plurality of threaded elements and a plurality of shearing blocks which are coaxially sleeved on the core shaft and rotate synchronously with the core shaft; each of the shearing blocks comprises a plurality of shearing pieces arranged in sequence from front to back, each of the shearing pieces has at least two convex portions protruding radially outward, and the convex portions on each of the shearing blocks are arranged in a spiral direction from front to back; the extrusion screw comprises a feeding section, a conveying section, a plasticizing section, an exhaust section and a pressure building section in sequence from front to back, and the length of the plasticizing section is greater than the lengths of the other sections; the plasticizing section is divided into a first plasticizing section, an exhaust section and a second plasticizing section in sequence from front to back The exhaust section is composed of a plurality of the threaded elements connected in sequence from front to back and at least part of the core shaft, and the first plasticizing section and the second plasticizing section are respectively composed of a plurality of the threaded elements, a plurality of the shearing blocks and at least part of the core shaft; in the plasticizing section, the shearing blocks connected front to back form a shearing portion in the circumferential direction of the core shaft, and the threaded elements connected front to back form a threaded portion in the circumferential direction of the core shaft, and the shearing portions and the threaded portions are alternately distributed from front to back, and the total length of the shearing portion of the first plasticizing section is greater than the total length of the shearing portion of the second plasticizing section.

2. The twin-screw extruder according to claim 1, characterized in that: Each of the threaded elements and each of the shear blocks are keyed to the mandrel.

3. The twin-screw extruder according to claim 2, characterized in that: The feeding section, conveying section, exhaust section and pressure building section are respectively composed of a plurality of the threaded elements and at least part of the core shaft.

4. The twin-screw extruder according to claim 3, characterized in that: The plurality of threaded elements all have double threads, and the double threads of the connected threaded elements respectively form a continuous main thread and a secondary thread, and the main thread and the secondary thread are arranged alternately from front to back.

5. The twin-screw extruder according to claim 4, characterized in that: The lead of the secondary thread of each of the threaded elements is equal to the lead of the main thread, the lead of the main thread of the feeding section is greater than or equal to the lead of the main thread of the conveying section, the lead of the main thread of the exhaust section is smaller than the lead of the main thread of the feeding section and greater than the lead of the main thread of the pressure building section, the lead of the main thread of the exhaust section is equal to the lead of the main thread of the exhaust section, and the lead of the main thread of the first plasticizing section and the lead of the main thread of the second plasticizing section are both smaller than the lead of the main thread of the exhaust section.

6. The twin-screw extruder according to claim 5, characterized in that: The lead of the main thread of the first half of the conveying section is greater than the lead of the main thread of the second half of the conveying section, and is equal to the lead of the main thread of the feeding section; the lead of the main thread of the first half of the pressure building section is greater than the lead of the main thread of the second half of the pressure building section.

7. The twin-screw extruder according to claim 1, characterized in that: The aspect ratio of the extrusion screw is 40-48.

8. The twin-screw extruder according to claim 1, characterized in that: The twin-screw barrel is provided with a first exhaust port and a second exhaust port, the position of the first exhaust port corresponds to the position of the exhaust section, the position of the second exhaust port corresponds to the position of the exhaust section, and the second exhaust port is connected to a vacuum system.

9. The twin-screw extruder according to claim 1, characterized in that: The twin-screw barrel is divided into several areas from front to back, each of the areas is equipped with a temperature control module, and each of the temperature control modules is used to adjust the temperature of each of the areas.

10. The twin-screw extruder according to claim 1, characterized in that: The driving assembly includes a DC motor and a gear box. The gear box is connected to the DC motor through a safety coupling. The safety coupling is equipped with a sensor. The sensor is connected to the DC motor signal.

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