Extrusion device for PVC sheet production line

Abstract

The utility model discloses an extrusion device for a PVC sheet production line, the extrusion device comprises a rack, an extruder, a hanging bracket and an extrusion die, the extruder comprises a machine barrel, an extrusion screw rotationally arranged in the machine barrel, a driving assembly in transmission connection with the extrusion screw, and a temperature control system; the extrusion screw comprises a rod body extending from front to back and a main thread spirally extending along the rod body, the compression ratio of the extrusion screw is 1.5-4.0, the rod body sequentially comprises a feeding section, a compression section, a plasticizing section, a homogenizing section and a mixing section from front to back, a first material groove spirally extending is formed in the main thread of the plasticizing section, and the volume of the first material groove is gradually increased from front to back; the temperature control system is communicated with the machine barrel, the extrusion screw and the driving assembly so as to respectively adjust the temperature of the machine barrel, the temperature of the extrusion screw and the temperature of the driving assembly; the extrusion screw is high in plasticizing capacity, the temperature of extruded materials is proper, and the appearance and performance of a final PVC product can be improved easily.

Description

Technical Field

[0001] The present application relates to the technical field of sheet production equipment, and in particular to an extrusion device for a PVC sheet production line. Background Art

[0002] PVC materials have poor thermal stability. If the temperature is low, PVC will not plasticize, but if the temperature is too high, PVC will easily decompose. The extrusion equipment currently used in the production of PVC infusion bags has a poor plasticizing effect on PVC materials and cannot guarantee the temperature during plasticization, resulting in a matte surface on the PVC products, affecting product quality. Summary of the invention

[0003] In order to solve the above-mentioned technical problems, the purpose of this application is to provide an extrusion device for a PVC sheet production line with good plasticizing effect.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: an extrusion device for a PVC sheet production line, comprising a frame, an extruder mounted on the frame, a hanger arranged on the frame and an extrusion die arranged on the hanger, the extruder comprising a barrel, an extrusion screw rotatably arranged in the barrel, a drive assembly and a temperature control system connected to the extrusion screw, the extrusion die is fluidly connected to the barrel, the extrusion screw comprises a rod body extending from front to back and a main thread extending helically along the rod body, the compression ratio of the extrusion screw is 1.5 to 4.0, the rod body is sequentially divided into a feeding section, a compression section, a plasticizing section, a homogenizing section and a mixing section from front to back, and the main threads are distributed in the feeding section, the compression section, the plasticizing section and the homogenizing section. The feeding section is provided with secondary threads arranged alternately with the main threads from front to back, the bottom diameter of the compression section gradually increases from front to back, the main threads of the plasticizing section are provided with a first material trough extending spirally, the volume of the first material trough gradually increases from front to back, the mixing section is provided with a plurality of mixing groups distributed sequentially from front to back, each mixing group includes a plurality of diamond pins arranged sequentially along the circumference of the rod body, the length of the plasticizing section is greater than the length of other sections, the outer diameters of the main threads and the secondary threads remain unchanged from front to back, and the outer diameters of the main threads and the secondary threads are equal; the temperature control system is connected with the barrel, the extrusion screw and the drive assembly to respectively adjust the temperatures of the barrel, the extrusion screw and the drive assembly.

[0005] In the above technical solution, it is further preferred that the lead of the main thread of the feed section is consistent with the lead of the main thread of the homogenizing section, and the lead of the secondary thread is consistent with the lead of the main thread of the feed section.

[0006] In the above technical solution, it is further preferred that the first material trough separates the main thread of the plasticizing section into a main edge and a secondary edge extending spirally along the rod body, and the main edge and the secondary edge are alternately arranged along the axial direction of the rod body.

[0007] In the above technical solution, it is further preferred that the rear end face of the main edge, the outer surface of the plasticizing section and the front end face of the secondary edge define the first material trough, the rear end face of the secondary edge, the outer surface of the plasticizing section and the front end face of the main edge define a second material trough, and the volume of the second material trough gradually decreases from front to back.

[0008] In the above technical solution, it is further preferred that the diamond pins of two adjacent mixing groups are alternately arranged in the circumferential direction of the rod body.

[0009] In the above technical solution, it is further preferred that the extrusion mold includes a front mold body and a rear mold body which are relatively arranged front and back, the rear mold body is detachably connected to the front mold body, and the front mold body and the rear mold body can be movably arranged on the hanger along the front and back directions respectively.

[0010] In the above technical solution, it is further preferred that the extrusion device also includes a pair of lifting hoists, and the front mold body and the rear mold body are respectively connected to one of the lifting hoists, and each of the lifting hoists is used to drive one of the front mold body and the rear mold body to move closer to or away from the other of the front mold body and the rear mold body.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The extrusion screw of the present application has high plasticizing capacity and suitable extrusion material temperature, which is beneficial to improving the appearance and performance of the final PVC product. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the structure of an extrusion device provided in an embodiment of the present application;

[0014] Figure 2 for Figure 1 A schematic diagram of the structure of an extrusion screw of an extrusion device;

[0015] Figure 3 for Figure 2 A schematic diagram of the structure of the plasticizing section of the extrusion screw;

[0016] Figure 4 for Figure 2 A schematic diagram of the structure of the mixing section of the extrusion screw;

[0017] Wherein: 100, extrusion device; 10, frame; 20, extruder; 1, barrel; 2, extrusion screw; 21, rod body; 211, feeding section; 212, compression section; 213, plasticizing section; 214, homogenizing section; 215, mixing section; 22, main thread; 221, main edge; 222, secondary edge; 23, secondary thread; 24, first trough; 25, second trough; 26, mixing group; 261, diamond pin; 3, drive assembly; 4, vacuum unloading assembly; 41, vacuum loader; 42, hopper; 30, hanger; 40, extrusion mold; 51, front mold body; 52, rear mold body; 6, lifting hoist. DETAILED DESCRIPTION

[0018] 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.

[0019] In the description of the present application, unless otherwise specified, “plurality” means two or more.

[0020] The “front” and “back” mentioned in this application are as follows: Figure 2 Before and after shown.

[0021] 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.

[0022] The present application provides an extrusion device for a PVC sheet production line, Figure 1 As shown, the extrusion device 100 includes a frame 10, an extruder 20 mounted on the frame 10, a hanger 30 disposed on the frame 10, and an extrusion die 40 disposed on the hanger 30. The extruder 20 includes a barrel 1, an extrusion screw 2 rotatably disposed in the barrel 1, a drive assembly 3 and a temperature control system connected to the extrusion screw 2, and the extrusion die 40 is fluidly connected to the barrel 1 to receive the plasticized material extruded from the extruder 20 and extrude the material into shape.

[0023] like Figure 2 As shown, the extrusion screw 2 includes a rod body 21 extending from front to back and a main thread 22 spirally extending along the rod body 21. The rod body 21 is composed of a feeding section 211, a compression section 212, a plasticizing section 213, a homogenizing section 214 and a mixing section 215 from front to back. The main thread 22 is distributed in the feeding section 211, the compression section 212, the plasticizing section 213 and the homogenizing section 214. The outer diameter of the main thread 22 on the rod body 21 is uniform and unchanged from front to back. The compression ratio of the extrusion screw 2 is 1.5 to 4.0. The appropriate compression ratio improves the plasticizing effect of the extrusion screw 2 on the PVC material.

[0024] The feed section 211 is provided with secondary threads 23 which are arranged alternately with the main threads 22 from front to back. The double threads of the feed section 211 help to increase the material intake of the extrusion screw 2 and further increase the output of the extruder 20. The outer diameter and lead of the secondary threads 23 are consistent with the outer diameter and lead of the main threads 22 of the feed section 211.

[0025] The bottom diameter of the compression section 212 gradually increases from front to back, and the material is compressed and conveyed backward in the compression section 212 , and a stable conveying pressure is established before the material plasticizing section 213 .

[0026] like Figure 2 , 3 As shown, a first material groove 24 extending in a spiral is provided on the main thread 22 of the plasticizing section 213. The first material groove 24 divides the main thread 22 of the plasticizing section 213 into a main edge 221 and a secondary edge 222 extending in a spiral along the rod body 21. The main edge 221 and the secondary edge 222 are alternately arranged along the axial direction of the rod body 21. The rear end face of the main edge 221, the outer surface of the plasticizing section 213 and the front end face of the secondary edge 222 define the first material groove 24, and the volume of the first material groove 24 gradually increases from front to back; the rear end face of the secondary edge 222, the outer surface of the plasticizing section 213 and the front end face of the main edge 221 define a second material groove 25, and the volume of the second material groove 25 gradually decreases from front to back. The material enters the plasticizing section 213 and is sheared by the main edge 221 and the secondary edge 222 to be fully plasticized and melted. More and more solid phase material is plasticized and melted into a melt, so the volume of the first material trough 24 increases and the volume of the second material trough 25 decreases, which is in line with the solid-liquid phase transformation process of the material.

[0027] The lead of the main thread 22 of the homogenizing section 214 is consistent with the lead of the main thread 22 of the feeding section 211. The material is stirred evenly in the homogenizing section 214 and the conveying pressure is stabilized to prevent the material from being over-plasticized.

[0028] like Figure 2 , 4As shown, the mixing section 215 is provided with a plurality of mixing groups 26 sequentially distributed from front to back, each mixing group 26 includes a plurality of rhombus pins 261 sequentially arranged along the circumference of the rod body 21, each rhombus pin 261 protrudes radially outward from the surface of the rod body 21, and the rhombus pins 261 of two adjacent mixing groups 26 are alternately arranged in the circumference of the rod body 21. The plurality of rhombus pins 261 of the mixing section 215 mix the material evenly, reduce the extrusion temperature, and establish a stable extrusion pressure.

[0029] In the present application, the length of the plasticizing section 213 is greater than that of other sections so as to fully plasticize the material. The shear force of other sections on the material is relatively small, so as to avoid the material being sheared for a long time and being over-plasticized, thereby improving the plasticizing effect of the material in the extruder 20.

[0030] The temperature control system is connected to the barrel 1, the extrusion screw 2 and the drive assembly 3 to adjust the temperature of the barrel 1, the extrusion screw 2 and the drive assembly 3. The temperature control system performs zoning control on the barrel 1. The temperature control of the barrel 1 discharge port effectively avoids the material from bridging at the discharge port, improves the discharge efficiency, and divides the barrel 1 from front to back into multiple areas for separate temperature control to avoid the barrel 1 temperature exceeding the set range and affecting the plasticization effect of the material in the barrel 1. The temperature control system controls the extrusion screw 2 to avoid the material from being burned due to overheating and improves the plasticization effect of the material. The temperature control system performs temperature control on the drive assembly 3 to avoid the drive assembly 3 from overheating after working for a long time and affecting the performance, thereby extending the service life of the drive assembly 3.

[0031] The thermal stability of PVC material is poor. If the temperature in the barrel 1 is low, the PVC will not be plasticized. If the temperature of the barrel 1 and the extrusion screw 2 is too high, the PVC will be easily decomposed. Therefore, the extruder 20 of the present application controls the temperature of the barrel 1 and the extrusion screw 2, and applies appropriate shear force to the PVC material in the plasticizing section 213 of the extrusion screw 2, so that the PVC material is fully plasticized in the extruder 20, thereby improving the quality of the final product.

[0032] like Figure 1 As shown, the discharge port of the barrel 1 is also provided with a vacuum discharge component 4, which includes a vacuum loader 41 and a hopper 42. The vacuum loader 41 sucks the raw materials into the hopper 42, and the hopper 42 guides the raw materials into the discharge port in the barrel 1. No manual handling is required, which saves time and effort and improves the discharge efficiency.

[0033] A metering pump (not shown in the figure) is also provided between the barrel 1 of the extruder 20 and the extrusion die 40. The metering pump is used to adjust the flow rate of the material delivered from the extruder 20 to the extrusion die 40, effectively improving the extrusion efficiency of the extrusion die 40 and the quality of the extruded product. A temperature control system is separately provided for the metering pump to keep the material delivered from the extruder 20 to the extrusion die 40 warm.

[0034] The extrusion die 40 includes a front die 51 and a rear die 52 which are arranged relative to each other in the front and rear directions. The front die 51 and the rear die 52 are detachably connected, and both can be movably arranged on the hanger 30 in the front and rear directions. The front die 51 and the rear die 52 are both provided with temperature control components, which are used to adjust the temperature of the extrusion flow channel in the extrusion die 40 to ensure the temperature of the material in the extrusion flow channel and avoid the temperature affecting the extrusion effect of the material. After the extrusion device 100 is completed, the front die 51 and the rear die 52 can be opened and moved away from each other to facilitate online cleaning and maintenance, saving time and effort.

[0035] Since the mold is relatively large and heavy, a lifting hoist 6 is respectively installed on the front mold body 51 and the rear mold body 52. ​​Each lifting hoist 6 drives the corresponding mold body away from the other mold body, saving labor and further improving work efficiency.

[0036] The extrusion screw of the present application has high plasticizing capacity and suitable extrusion material temperature, which is beneficial to improving the appearance and performance of the final PVC product.

[0037] 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 to 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 claimed in the present application is defined by the attached claims, description and their equivalents.

Claims

1. An extrusion device for a PVC sheet production line, comprising a frame, an extruder mounted on the frame, a hanger arranged on the frame and an extrusion die arranged on the hanger, wherein the extruder comprises a barrel, an extrusion screw rotatably arranged in the barrel, a drive assembly and a temperature control system connected to the extrusion screw, the extrusion die is in fluid communication with the barrel, and is characterized in that: The extrusion screw comprises a rod body extending from front to back and a main thread extending spirally along the rod body. The compression ratio of the extrusion screw is 1.5 to 4.

0. The rod body is composed of a feeding section, a compression section, a plasticizing section, a homogenizing section and a mixing section from front to back. The main thread is distributed in the feeding section, the compression section, the plasticizing section and the homogenizing section. The feeding section is provided with a secondary thread arranged alternately with the main thread from front to back. The bottom diameter of the compression section gradually increases from front to back. The main thread of the plasticizing section is provided with a first material trough extending spirally. The first material trough The volume increases gradually from front to back, the mixing section is provided with a plurality of mixing groups distributed sequentially from front to back, each mixing group includes a plurality of rhombus pins arranged sequentially along the circumference of the rod body, the length of the plasticizing section is greater than the lengths of other sections, the outer diameters of the main thread and the secondary thread remain unchanged from front to back, and the outer diameters of the main thread and the secondary thread are equal; the temperature control system is connected with the barrel, the extrusion screw and the drive assembly to respectively adjust the temperatures of the barrel, the extrusion screw and the drive assembly.

2. The extrusion device according to claim 1, characterized in that The lead of the main thread of the feed section is consistent with the lead of the main thread of the homogenizing section, and the lead of the secondary thread is consistent with the lead of the main thread of the feed section.

3. The extrusion device according to claim 1, characterized in that: The first material trough divides the main thread of the plasticizing section into a main edge and a secondary edge that extend spirally along the rod body, and the main edge and the secondary edge are alternately arranged along the axial direction of the rod body.

4. The extrusion device according to claim 3, characterized in that: The rear end face of the main edge, the outer surface of the plasticizing section and the front end face of the secondary edge define the first material trough, the rear end face of the secondary edge, the outer surface of the plasticizing section and the front end face of the main edge define a second material trough, and the volume of the second material trough gradually decreases from front to back.

5. The extrusion device according to claim 1, characterized in that: The diamond pins of two adjacent mixing groups are alternately arranged in the circumferential direction of the rod body.

6. The extrusion device according to claim 1, characterized in that: The extrusion die comprises a front die body and a rear die body which are arranged relatively front and back, the rear die body is detachably connected to the front die body, and the front die body and the rear die body are respectively movably arranged on the hanger along the front and back directions.

7. The extrusion device according to claim 6, characterized in that The extrusion device also includes a pair of lifting hoists, and the front mold body and the rear mold body are respectively connected to one of the lifting hoists, and each of the lifting hoists is used to drive one of the front mold body and the rear mold body to move closer to or away from the other of the front mold body and the rear mold body.

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