Dynamic constant-pressure precise feeding device for PP packing belt production

Abstract

The invention discloses a dynamic constant-pressure precise feeding device for PP packing belt production, and relates to forming material conveying, the dynamic constant-pressure precise feeding device comprises a machine body and further comprises an extrusion assembly arranged on the upper portion of the machine body, the extrusion assembly comprises an extrusion barrel arranged above the machine body and used for achieving feeding, and a screw is rotationally connected into the extrusion barrel; a scale scraping assembly used for removing scale generated during circulating cooling is arranged in the screw. The scale scraping assembly comprises a two-way lead screw arranged at the circle center in the screw rod, the two ends of the two-way lead screw are rotationally connected with positioning frames, the outer sides of the positioning frames are fixedly connected with the inner wall of the screw rod, a scraping ring is arranged outside the two-way lead screw, a scraper is fixedly connected to the outer circle face of the scraping ring, and turbine blades are fixedly connected to one end in the two-way lead screw. A limiting rod is fixedly connected between the positioning frames and movably penetrates through the scraping ring; and by removing scale generated by cooling water on the inner wall of the screw, the heat conduction efficiency during cooling is guaranteed, the screw is cooled stably, and the feeding uniformity is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of molding material conveying, and in particular to a dynamic constant pressure precision feeding device for producing PP strapping tapes. Background Art

[0002] The automatic precision feeding system for PP strapping tape production refers to the stage where the raw materials for strapping tape production are introduced into the extruder and then melted and extruded by the extruder. The most important link in the production process of PP strapping tape is feeding, because uneven feeding will lead to large errors in important parameters such as width, toughness and gram weight of the final product, resulting in a significant decrease in the yield rate; The discharge of the extruder is affected by the screw speed, feed amount, material properties, temperature, filter blockage, etc. The screw speed and feed amount can be controlled by adjusting the motor speed, and the material properties can be adjusted accordingly. When the filter is blocked, it can be replaced by an automatic screen changer, and the temperature can be controlled by the cooling system. Generally, the heating cylinder is often cooled by air cooling cycle, while the screw is usually cooled by water cooling cycle. When using water cooling cycle, the cooling water is easy to scale, which leads to an increase in the thickness of the inner wall of the screw, affecting the heat transfer efficiency and the cooling of the screw. If the screw temperature is too high, the melt will not flow smoothly, affecting the feeding efficiency and quality. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the heat transfer efficiency of the traditional screw is reduced due to scaling during the cooling process, thereby affecting the cooling effect and further affecting the forward movement of material conveying, and to propose a dynamic constant pressure precision feeding device for PP strapping tape production.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a dynamic constant pressure precision feeding device for PP strapping production, comprising a machine body, and also comprising an extrusion assembly arranged on the upper part of the machine body, the extrusion assembly comprising an extrusion barrel arranged above the machine body for feeding, a screw is rotatably connected inside the extrusion barrel, and a scraping assembly for removing scale generated during circulating cooling is arranged inside the screw; The scraper assembly includes a bidirectional screw rod arranged at the inner center of the screw rod, both ends of the bidirectional screw rod are rotatably connected with positioning frames, and the outer side of the positioning frame is fixedly connected to the inner wall of the screw rod, a scraper ring is arranged on the outside of the bidirectional screw rod, and a scraper is fixedly connected to the outer circular surface of the scraper ring, a turbine blade is fixedly connected to one end of the inner side of the bidirectional screw rod, a limiting rod is fixedly connected between the positioning frames, and the limiting rod movably passes through the scraper ring.

[0005] As a further description of the above technical solution: The bidirectional screw rod is in the shape of a column with two ends open and an interior hollow, and a gap is left between one end of the bidirectional screw rod away from the turbine blade and the inner wall of the screw rod.

[0006] As a further description of the above technical solution: Both sides of the scraper ring are provided with grinding components, and the grinding components include movable grooves arranged on both sides of the scraper ring, and the interior of the movable groove is rotatably connected with a grinding ring.

[0007] As a further description of the above technical solution: The sides of the frosted rings that are away from each other extend to the outside of the movable groove, and the inner surface of the frosted rings located in the area outside the movable groove and the outer wall of the limiting rod are both provided with spiral patterns, and the limiting rod and the frosted rings are connected by spiral transmission through the spiral patterns.

[0008] As a further description of the above technical solution: A scale inhibition component is provided between the scraper ring and the bidirectional screw rod. The scale inhibition component comprises a permanent magnet ring movably sleeved on the outside of the bidirectional screw rod. A connecting column is fixedly connected between the permanent magnet ring and the scraper ring. The scraper ring is made of a permanent magnet.

[0009] As a further description of the above technical solution: The inner circular surface of the permanent magnet ring is provided with a sliding block which slides inside the sliding groove on the surface of the bidirectional screw rod.

[0010] As a further description of the above technical solution: The number of the limiting rods is four, and the four limiting rods are distributed in a circular array on the circular track of the inner circular surface of the frosted ring.

[0011] As a further description of the above technical solution: The extrusion assembly also includes a driving unit arranged at the upper end of the body for driving the screw to rotate, a heating cylinder is movably sleeved on the outside of the extrusion barrel, a feed hopper is fixedly connected to the upper end of the extrusion barrel, a screen changer is movably connected to one end of the extrusion barrel away from the driving unit, and a die head is movably connected to the other end of the screen changer, and an inspection window is provided at the front end of the body.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The turbine blades are driven to rotate by the impact of cooling water, so the rotation of the turbine blades drives the bidirectional screw to rotate synchronously. When the bidirectional screw rotates, it can drive the scraper ring on its surface to move back and forth left and right. During displacement, the restriction of the limiting rod can prevent the scraper ring from rotating, so that it can only move left and right. During the displacement process, the scraper on the surface of the scraper ring can scrape off the scale attached to the inner wall of the screw, and the scraped scale is discharged with the cooling water, thereby reducing the probability of a decrease in heat conduction efficiency during the water cooling process due to scale coverage, ensuring the stability of the screw cooling, making it stable for material transportation, and ensuring the uniformity of the feed when the material is extruded. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 An overall schematic diagram provided according to an embodiment of the present invention is shown; Figure 2 It shows a view of the combination of an extrusion cylinder and a heating cylinder provided in an embodiment of the present invention; Figure 3 A schematic diagram of the internal structure of an extrusion barrel provided according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of the internal structure of a screw provided in an embodiment of the present invention is shown; Figure 5 The embodiment of the present invention provides Figure 4 Enlarged view of point A in the middle; Figure 6 A schematic diagram of the internal structure of a bidirectional screw rod provided in an embodiment of the present invention is shown; Figure 7 A schematic diagram of the combination of a scale grinding component and a scale suppression component provided according to an embodiment of the present invention is shown.

[0014] Legend: 10. Body; 20. Extrusion assembly; 21. Driving unit; 22. Extrusion barrel; 23. Heating barrel; 24. Feed hopper; 25. Screen changer; 26. Die head; 27. Inspection window; 28. Screw; 30. Scraping assembly; 31. Bidirectional screw rod; 32. Positioning frame; 33. Scraping ring; 34. Limiting rod; 35. Turbine blade; 36. Scraper; 40. grinding component; 41. movable groove; 42. grinding ring; 43. spiral pattern; 50. Anti-scaling component; 51. Permanent magnetic ring; 52. Connecting column. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] like Figure 1-Figure 7 As shown, the present invention provides a dynamic constant pressure precision feeding device for PP strapping production: The machine body 10 includes an extrusion assembly 20 disposed on the upper part of the machine body 10, the extrusion assembly 20 includes an extrusion barrel 22 disposed above the machine body 10 for feeding, the interior of the extrusion barrel 22 is rotatably connected to a screw 28, the extrusion assembly 20 also includes a driving unit 21 disposed at the upper end of the machine body 10 for driving the screw 28 to rotate, the exterior of the extrusion barrel 22 is movably sleeved with a heating barrel 23, the upper end of the extrusion barrel 22 is fixedly connected to a feed hopper 24, one end of the extrusion barrel 22 away from the driving unit 21 is movably connected to a screen changer 25, and the other end of the screen changer 25 is movably connected to a die head 26, and an inspection window 27 is provided at the front end of the machine body 10.

[0017] A scraper assembly 30 for removing scale generated during circulating cooling is provided inside the screw 28; the scraper assembly 30 includes a bidirectional screw 31 provided at the inner center of the screw 28, two ends of the bidirectional screw 31 are rotatably connected with positioning frames 32, and the outer side of the positioning frame 32 is fixedly connected to the inner wall of the screw 28, a scraper ring 33 is provided outside the bidirectional screw 31, and a scraper 36 is fixedly connected to the outer circumferential surface of the scraper ring 33, one end of the inside of the bidirectional screw 31 is fixedly connected with a turbine blade 35, a limiting rod 34 is fixedly connected between the positioning frames 32, and the limiting rod 34 movably passes through the scraper ring 33; the bidirectional screw 31 is a columnar body with openings at both ends and a hollow interior, and a gap is left between the end of the bidirectional screw 31 away from the turbine blade 35 and the inner wall of the screw 28.

[0018] Specifically, the raw material polypropylene resin particles for producing the PP strapping tape are first transported to the inside of the feed hopper 24 through the feed pump, and then the material enters the extrusion barrel 22 through the feed hopper 24, and the screw 28 is controlled to rotate by the driving unit 21 to realize the transportation of the material. During the transportation process, the material is heated and melted by the heating barrel 23. The molten material is first filtered through the screen inside the screen changer 25 under the continuous transportation of the screw 28, and then discharged after being shaped by the die head 26, so as to realize the feeding operation for the next level of production of the PP strapping tape; It should be noted that the structure of the driving unit 21 and how the driving unit 21 drives the screw 28 to rotate are both prior arts and common knowledge in the art, so the structure and principle thereof will not be described in detail herein. During the material extrusion process, the screw 28 continuously rubs against the material, thereby increasing the temperature of the screw 28. The increased temperature of the screw 28 will cause the plasticization temperature of the material to be too high and decompose, and will also affect the forward movement of the material, resulting in unstable discharge. Therefore, the screw 28 needs to be circulated and cooled. The water cooling system of the screw 28 is common knowledge in the art, so how to introduce cooling water into the interior of the screw 28 will not be described in detail here. During cooling, cooling water enters the inside of the bidirectional screw 31 inside the screw 28, and then the cooling water enters the inside of the screw 28 from the other end of the bidirectional screw 31, and refluxes from the inside of the screw 28 to form circulating cooling. During the circulating cooling process, since the inside of the bidirectional screw 31 is fixedly connected with the turbine blade 35, the cooling water impacts the turbine blade 35 to drive it to rotate. Since the two ends of the bidirectional screw 31 are movably connected to the inside of the positioning frame 32, the turbine blade 35 drives the bidirectional screw 31 to rotate synchronously when it rotates. When the bidirectional screw 31 rotates, it can drive the scraper ring 33 on its surface to move back and forth left and right. When it moves, it passes through the limiting rod 34 The restriction can prevent the scraper ring 33 from rotating, so that it can only move left and right. During the displacement process, the scraper 36 on the surface of the scraper ring 33 can scrape off the scale attached to the inner wall of the screw 28, and the scraped scale is discharged with the cooling water, thereby reducing the probability of a decrease in heat conduction efficiency during the water cooling process caused by scale coverage, ensuring the stability of the cooling of the screw 28, making it stable for material transportation, and ensuring the uniformity of feeding when the material is extruded. At the same time, during the cooling process, the scraper ring 33 always continuously drives the scraper 36 to scrape the inner wall of the screw 28, while removing the scale, it also reduces the formation and accumulation of scale, making it more convenient and easy to clean the scale; It should be noted that in order to prevent the cooling water from overheating, the cooling water needs to circulate quickly inside the screw 28. Therefore, a booster pump is needed to increase the pressure when injecting the cooling water, so as to ensure that the cooling water has a strong enough water pressure when entering the bidirectional screw 31. Under the action of such high water pressure, the turbine blades 35 will inevitably be driven to rotate and the bidirectional screw 31 will be driven to rotate synchronously.

[0019] like Figure 5 and Figure 7 As shown, both sides of the scraper ring 33 are provided with a grinding assembly 40, and the grinding assembly 40 includes a movable groove 41 opened on both sides of the scraper ring 33, and the inner part of the movable groove 41 is rotatably connected with a frosting ring 42; the side of the frosting ring 42 away from each other extends to the outside of the movable groove 41, and the inner circular surface of the frosting ring 42 is located in the area outside the movable groove 41 and the outer wall of the limiting rod 34 are provided with a spiral pattern 43, and the limiting rod 34 is spirally connected to the frosting ring 42 through the spiral pattern 43. The number of the limiting rods 34 is four, and the four limiting rods 34 are distributed in a circular array on the circular track of the inner circular surface of the frosting ring 42.

[0020] Specifically, since scale will stubbornly adhere to the inner wall of the screw 28 after long-term accumulation, if it is directly scraped off by the scraper 36, it is easy to cause wear to the scraper 36 and the inside of the screw 28, thereby affecting the subsequent scale scraping effect; Based on this, a scale grinding assembly 40 is set on both sides of the scraper 36. When the scraper ring 33 moves left and right, the grinding ring 42 first grinds the scale through sliding friction, and then uses the scraper 36 to scrape off the ground scale. On the one hand, the ground scale is easier to scrape off, and on the other hand, it also reduces the wear on the scraper 36 and the inner wall of the screw 28 when scraping the scale, thereby ensuring the effect of subsequent scale scraping and further improving the scale removal effect. In addition, since the grinding ring 42 is connected by a spiral transmission through the spiral pattern 43, and the four limiting rods 34 are distributed in a circular array on the circular track of the inner surface of the grinding ring 42, a spiral transmission combination of bolts and nuts is formed between the grinding ring 42 and the limiting rods 34. Therefore, when the grinding ring 42 is displaced left and right, it will be driven to rotate by the spiral pattern 43. Compared with translational grinding, the grinding ring 42 can grind the scale better by rotating while displacing, thereby further improving the scale removal effect and ensuring the stable and uniform feeding.

[0021] like Figure 5 and Figure 7 As shown, a scale inhibition component 50 is provided between the scraper ring 33 and the bidirectional screw rod 31. The scale inhibition component 50 includes a permanent magnet ring 51 movably sleeved on the outside of the bidirectional screw rod 31. A connecting column 52 is fixedly connected between the permanent magnet ring 51 and the scraper ring 33. The scraper ring 33 is made of a permanent magnet. The inner circular surface of the permanent magnet ring 51 is provided with a slider that slides inside the sliding groove on the surface of the bidirectional screw rod 31.

[0022] Specifically, after the cooling water enters the bidirectional screw 31, the cooling water will pass through the permanent magnet ring 51. At this time, the magnetic field generated by the permanent magnet ring 51 can change the structure of the particles in the water, making it less likely to adhere to the wall surface, thereby reducing the formation of scale. After that, the cooling water flows out from the other end of the bidirectional screw 31, and when it flows back from the inside of the screw 28, it passes through the scraper ring 33 again. The scraper ring 33 is also made of permanent magnets. Therefore, the magnetic field formed by the scraper ring 33 is used to change the structure of the particles in the water again, further reducing the probability of scale formation. In addition, the left and right reciprocating motion of the scraper ring 33 can also increase the coverage of the magnetic field on the cooling water, further inhibiting the formation of scale. By solving the influence of scale on the cooling of the screw 28 from the source, the stability and uniformity of the feed are again guaranteed.

[0023] Instructions for use: First, the raw material polypropylene resin particles for producing PP strapping tape are conveyed to the inside of the feed hopper 24 through the feeding pump, and then the material enters the extrusion barrel 22 through the feed hopper 24, and the screw 28 is controlled to rotate by the driving unit 21 to realize the conveying of the material. During the conveying process, the material is heated and melted by the heating barrel 23. During the extrusion process of the material, the screw 28 continuously rubs against the material, thereby increasing the temperature of the screw 28. At this time, cooling water is passed into the inside of the bidirectional screw 31 inside the screw 28, and then the cooling water enters the inside of the screw 28 from the other end of the bidirectional screw 31, and refluxes from the inside of the screw 28 to form a circulating cooling. During the circulating cooling process, since the inside of the bidirectional screw 31 is fixedly connected with the turbine blade 35, the cooling water impacts the turbine blade 35 to drive it to rotate, and the rotation of the turbine blade 35 drives the bidirectional screw 31 to rotate synchronously, and the bidirectional screw 31 rotates synchronously. When the screw 31 rotates, the scraper ring 33 on its surface can be driven to move back and forth left and right. During the displacement process, the scraper 36 on the surface of the scraper ring 33 can scrape off the scale attached to the inner wall of the screw 28, and the scraped scale is discharged with the cooling water. At the same time, during the cooling process, the scraper ring 33 always continuously drives the scraper 36 to scrape the inner wall of the screw 28. While removing the scale, it also reduces the formation and accumulation of scale, making it more convenient and easy to clean the scale. Finally, the molten material is continuously conveyed by the screw 28, first filtered by the screen inside the screen changer 25, and then discharged after being shaped by the die head 26, so as to realize the feeding operation for the next level of production of the PP strapping tape. By removing the scale, the probability of a decrease in heat conduction efficiency during the water cooling process caused by scale coverage is reduced, thereby ensuring the stability of the cooling of the screw 28, making it stable for material transportation, and ensuring the stability and uniformity of the feeding when the material is extruded.

[0024] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A dynamic constant pressure precision feeding device for PP strapping production, comprising a body (10), characterized in that: It also includes an extrusion assembly (20) disposed on the upper part of the machine body (10), the extrusion assembly (20) including an extrusion barrel (22) disposed above the machine body (10) for feeding, a screw (28) rotatably connected to the interior of the extrusion barrel (22), and a scraping assembly (30) for removing scale generated during circulating cooling is provided inside the screw (28); The scraper assembly (30) comprises a bidirectional screw (31) disposed at the inner center of the screw (28), the two ends of the bidirectional screw (31) being rotatably connected to positioning frames (32), and the outer side of the positioning frame (32) being fixedly connected to the inner wall of the screw (28), a scraper ring (33) being disposed outside the bidirectional screw (31), and a scraper (36) being fixedly connected to the outer circumferential surface of the scraper ring (33), a turbine blade (35) being fixedly connected to one inner end of the bidirectional screw (31), and a limiting rod (34) being fixedly connected between the positioning frames (32), and the limiting rod (34) movably passes through the scraper ring (33).

2. A dynamic constant pressure precision feeding device for PP strapping production according to claim 1, characterized in that: The bidirectional screw rod (31) is in the form of a columnar body with both ends open and an interior hollow, and a gap is left between the end of the bidirectional screw rod (31) away from the turbine blade (35) and the inner wall of the screw rod (28).

3. A dynamic constant pressure precision feeding device for PP strapping production according to claim 2, characterized in that: A grinding assembly (40) is provided on both sides of the scraper ring (33), and the grinding assembly (40) comprises movable grooves (41) opened on both sides of the scraper ring (33), and a grinding ring (42) is rotatably connected inside the movable groove (41).

4. A dynamic constant pressure precision feeding device for PP strapping production according to claim 3, characterized in that: The side of the frosted ring (42) that is away from the frosted ring (42) extends to the outside of the movable groove (41), and the inner circular surface of the frosted ring (42) in the area outside the movable groove (41) and the outer wall of the limiting rod (34) are both provided with spiral patterns (43), and the limiting rod (34) and the frosted ring (42) are connected in a spiral transmission via the spiral patterns (43).

5. A dynamic constant pressure precision feeding device for PP strapping production according to claim 4, characterized in that: A scale suppression component (50) is provided between the scraper ring (33) and the bidirectional screw rod (31), the scale suppression component (50) comprising a permanent magnet ring (51) movably sleeved on the outside of the bidirectional screw rod (31), a connecting column (52) fixedly connected between the permanent magnet ring (51) and the scraper ring (33), and the scraper ring (33) is made of a permanent magnet.

6. A dynamic constant pressure precision feeding device for PP strapping production according to claim 5, characterized in that: The inner circular surface of the permanent magnet ring (51) is provided with a sliding block which slides inside a sliding groove on the surface of the bidirectional screw rod (31).

7. A dynamic constant pressure precision feeding device for PP strapping production according to claim 5, characterized in that: The number of the limiting rods (34) is four, and the four limiting rods (34) are distributed in a circular array on the circular track of the inner circular surface of the frosting ring (42).

8. A dynamic constant pressure precision feeding device for PP strapping production according to claim 5, characterized in that: The extrusion assembly (20) further comprises a driving unit (21) disposed at the upper end of the machine body (10) for driving the screw (28) to rotate; the outer portion of the extrusion barrel (22) is movably sleeved with a heating barrel (23); the upper end of the extrusion barrel (22) is fixedly connected to a feed hopper (24); one end of the extrusion barrel (22) away from the driving unit (21) is movably connected to a screen changer (25); and the other end of the screen changer (25) is movably connected to a die head (26); and a maintenance window (27) is provided at the front end of the machine body (10).

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