Blown film extrusion screw configuration

Abstract

The utility model provides a kind of extrusion screw structure of film blowing machine, including base, the top of base is fixedly installed with conveying cylinder, the top of conveying cylinder is equipped with the feeding hopper being communicated therewith, the discharge port of conveying cylinder is fixedly installed with filter box, the discharge port of filter box is fixedly installed with discharge nozzle, the inside of filter box is provided with filter assembly, the top of base is fixedly installed with motor located conveying cylinder one end, the bottom of filter box is detachably installed with pollution collection box. The filter assembly of being set, make reciprocating rod when being driven to rotate by conveying screw, reciprocating block drives reciprocating rod and its one end scraping strip to reciprocate sliding simultaneously, so that scraping strip removes impurity on the surface of filter plate, effectively reduce the blockage of filter plate due to impurity accumulation, ensure the smooth flow of plastic melt, maintain the stable working pressure of film blowing machine, to improve the quality and stability of blown film.

Description

Technical Field

[0001] This utility model relates to the field of plastic product manufacturing technology, and more specifically, to an extrusion screw structure for a blown film machine. Background Technology

[0002] A blown film machine is a mechanical device that heats and melts plastic particles and then blows them into a film. It mainly involves adding dry polyethylene particles into a hopper, where the particles enter the screw by their own weight. When the particles come into contact with the screw, the rotating inclined plane will generate a thrust on the plastic perpendicular to the inclined plane. This thrust causes the plastic particles to move forward.

[0003] Impurities are inevitably mixed in with plastic raw materials during the transportation process, so a filter screen needs to be installed at its outlet. Existing filter screens are generally fixed and will continuously trap impurities in the plastic melt during long-term filtration. Over time, the impurities accumulate more and more, and the filter screen is prone to clogging. Once the filter screen is clogged, the flow of the plastic melt is obstructed, the pressure distribution is unbalanced, and ultimately the quality of blown film is affected.

[0004] Therefore, we have made improvements to this and proposed an extrusion screw structure for a blown film machine. Utility Model Content

[0005] The purpose of this invention is that existing filter screens are generally fixed in place. During long-term filtration, they will continuously trap impurities in the plastic melt. Over time, the impurities accumulate more and more, and the filter screen is prone to clogging. Once the filter screen is clogged, the flow of the plastic melt is obstructed, the pressure distribution is unbalanced, and ultimately the quality of blown film is affected.

[0006] To achieve the above-mentioned objectives, this utility model provides the following technical solution:

[0007] An extrusion screw structure for a blown film machine includes a base, a conveying cylinder fixedly mounted on top of the base, a feed hopper connected to the conveying cylinder, a filter box fixedly mounted at the discharge port of the conveying cylinder, a discharge nozzle fixedly mounted at the discharge port of the filter box, a filter assembly disposed inside the filter box, a motor fixedly mounted on top of the base at one end of the conveying cylinder, a conveying screw rotatably fitted inside the conveying cylinder on the output shaft of the motor, a heating element mounted on the inner circumference of the conveying cylinder, and a sludge collection box detachably mounted at the bottom of the filter box.

[0008] Furthermore, the filter assembly includes a filter plate with multiple filter holes installed inside the filter box, the middle of both side plates of the filter box are through slots, and the inner wall of the filter box is equipped with a connecting cylinder located around the middle through slot.

[0009] Furthermore, a reciprocating rod is slidably fitted at the end of the conveying screw, a scraper is installed at the end of the reciprocating rod near the filter plate, a square strip is installed in the groove at the end of the conveying screw, and a square groove is opened at the end of the reciprocating rod to slidably fit with the square strip.

[0010] Furthermore, the end of the conveying screw is equipped with a first helical bevel gear, the central shaft of the first helical bevel gear is in a hollow state, the inner wall of the side of the filter box is provided with a rotating groove, the inner wall of the rotating groove is rotatably fitted with a rotating rod, and the circumference of the rotating rod is equipped with a second helical bevel gear that meshes with the first helical bevel gear.

[0011] Furthermore, a rotating disk is installed at the end of the rotating rod, and a reciprocating block is rotatably fitted around the periphery of the reciprocating rod. An arc-shaped reciprocating groove is opened on the side of the reciprocating block near the rotating disk, and a connecting shaft that mates with the arc-shaped reciprocating groove is installed on the side of the rotating disk near the reciprocating block.

[0012] Furthermore, a drain port is installed at the bottom of the connecting cylinder near the filter plate. The drain port is connected to the connecting cylinder and its opening faces downward. After the scraper removes the impurities attached to the surface of the filter plate, they fall into the sludge collection box at the bottom of the filter box through the drain port.

[0013] Furthermore, an opening and closing block is slidably fitted on the inner wall of the bottom opening of the sewage outlet. The opening and closing block is a triangular block with its vertex facing upward, and an L-shaped connecting rod is installed at the bottom of the opening and closing block.

[0014] Furthermore, the longitudinal rod of the L-shaped connecting rod passes through the outer wall of the connecting cylinder and is fitted with a beveled block at one end inside it. The beveled side of the beveled block faces one side of the reciprocating block. The lower side of the reciprocating block is arc-shaped and matches the beveled side of the beveled block. A spring is installed between the L-shaped connecting rod and the outer wall of the connecting cylinder.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] 1. This utility model, through the setting of the filter component, enables the reciprocating rod to rotate when driven by the conveying screw, while the reciprocating block drives the reciprocating rod and the scraper at one end to slide back and forth. This allows the scraper to scrape away impurities on the surface of the filter plate, effectively reducing the filter plate from clogging due to impurity accumulation, ensuring the smooth flow of plastic melt, maintaining the stable working pressure of the blown film machine, and thus improving the quality and stability of the blown film.

[0017] 2. When the scraper of this utility model moves towards the drain outlet to scrape off impurities on the surface of the filter plate, the L-shaped connecting rod drives the opening and closing block to move downward, opening the drain outlet. The scraped impurities fall into the collection box at the bottom of the filter box through the drain outlet. This eliminates the need for frequent manual disassembly of the filter plate for cleaning, reducing the labor intensity of operators and minimizing equipment downtime for maintenance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the extrusion screw structure of a blown film machine according to the present invention;

[0019] Figure 2 This is a side sectional view of the conveyor cylinder of this utility model.

[0020] Figure 3 This utility model Figure 2 -Enlarged structural diagram at point A;

[0021] Figure 4 This is a schematic diagram of the structure of the discharge nozzle connection of this utility model;

[0022] Figure 5 This utility model Figure 4 Enlarged structural diagram at point B;

[0023] Figure 6 This is a schematic diagram of the internal structure of the filter box of this utility model;

[0024] Figure 7 This is a schematic diagram of the structure of the filter assembly of this utility model.

[0025] The image shows:

[0026] 1. Base; 2. Conveying cylinder; 3. Feed hopper; 4. Filter box; 5. Filter assembly; 501. Filter plate; 502. Connecting cylinder; 503. Reciprocating rod; 504. Scraper; 505. Square bar; 506. Square groove; 507. First helical bevel gear; 508. Rotating groove; 509. Rotating rod; 510. Second helical bevel gear; 511. Rotating disk; 512. Drain outlet; 513. Opening and closing block; 514. L-shaped connecting rod; 515. Reciprocating block; 516. Spring; 517. Inclined block; 518. Arc-shaped reciprocating groove; 519. Connecting shaft; 6. Discharge nozzle; 7. Motor; 8. Conveying screw; 9. Heating element; 10. Sludge collection box. Detailed Implementation

[0027] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0028] Please refer to Figure 1-7An extrusion screw structure for a blown film machine includes a base 1, a conveying cylinder 2 fixedly mounted on the top of the base 1, a feed hopper 3 connected to the conveying cylinder 2, a filter box 4 fixedly mounted at the outlet of the conveying cylinder 2, a discharge nozzle 6 fixedly mounted at the outlet of the filter box 4, a filter assembly 5 disposed inside the filter box 4, a motor 7 fixedly mounted on one end of the conveying cylinder 2 on the top of the base 1, a conveying screw 8 rotatably fitted inside the conveying cylinder 2 on the output shaft of the motor 7, a heating element 9 mounted on the inner circumference of the conveying cylinder 2, and a sludge collection box 10 detachably mounted on the bottom of the filter box 4.

[0029] Specifically, after starting the motor 7, its output shaft drives the conveying screw 8 to rotate inside the conveying cylinder 2. Plastic particles enter the conveying cylinder 2 from the feed hopper 3 and move towards the discharge port along the conveying cylinder 2 under the push of the conveying screw 8. At the same time, the heating element 9 on the inner wall of the conveying cylinder 2 heats the plastic particles, causing them to gradually melt into plastic melt. The sludge collection box 10 is provided for easy collection of impurities, and the sludge collection box 10 is detachable, making it convenient to clean impurities and preventing impurities from scattering and affecting the working environment and equipment operation.

[0030] Please refer to Figure 3 and Figure 5 The filter assembly 5 includes a filter plate 501 with multiple filter holes installed inside the filter box 4. The middle sections of both side plates of the filter box 4 are through-grooves. A connecting cylinder 502 located around the middle through-groove is installed on the inner wall of the filter box 4. A reciprocating rod 503 is slidably fitted to the end of the conveying screw 8. A scraper 504 is installed at the end of the reciprocating rod 503 near the filter plate 501. A square strip 505 is installed in the groove at the end of the conveying screw 8. A square groove 506 is opened at the end of the reciprocating rod 503 to slidably fit with the square strip 505. A first helical bevel gear 507 is installed at the end of the conveying screw 8. The central shaft of the helical bevel gear 507 is hollow. The inner wall of the filter box 4 is provided with a rotating groove 508. The inner wall of the rotating groove 508 is rotatably fitted with a rotating rod 509. The circumference of the rotating rod 509 is provided with a second helical bevel gear 510 that meshes with the first helical bevel gear 507. The end of the rotating rod 509 is provided with a rotating disk 511. The circumference of the reciprocating rod 503 is rotatably fitted with a reciprocating block 515. The side of the reciprocating block 515 near the rotating disk 511 is provided with an arc-shaped reciprocating groove 518. The side of the rotating disk 511 near the reciprocating block 515 is provided with a connecting shaft 519 that mates with the arc-shaped reciprocating groove 518.

[0031] Specifically, the molten plastic enters the filter box 4 through the outlet of the conveying cylinder 2, and is filtered by the filter plate 501 in the filter assembly 5. Impurities are intercepted on the surface of the filter plate 501, and the filtered molten plastic is extruded from the outlet 6 and enters the subsequent blown film process. During the rotation of the conveying screw 8, the first helical bevel gear 507 at its end rotates synchronously. Since the first helical bevel gear 507 meshes with the second helical bevel gear 510, it drives the rotating rod 509 to rotate in the rotating groove 508. The rotating disk 511 at the end of the rotating rod 509... As the disc rotates, the connecting shaft 519 on the rotating disk 511 slides within the arc-shaped reciprocating groove 518, causing the reciprocating block 515 to reciprocate. Because the reciprocating rod 503 rotates with the reciprocating block 515, and the square strip 505 at the end of the conveying screw 8 slides with the square groove 506 of the reciprocating rod 503, when the reciprocating rod 503 is rotated by the conveying screw 8, the reciprocating block 515 simultaneously drives the reciprocating rod 503 and the scraper 504 at one end of it to reciprocate, causing the scraper 504 to scrape away impurities from the surface of the filter plate 501.

[0032] Please refer to Figure 2 and Figure 6 The bottom of the connecting cylinder 502 near the filter plate 501 is equipped with a drain port 512. The drain port 512 is connected to the connecting cylinder 502 and is set with its opening facing downward. After the scraper 504 scrapes off the impurities attached to the surface of the filter plate 501, they fall into the dirt collection box 10 at the bottom of the filter box 4 through the drain port 512. The inner wall of the bottom opening of the drain port 512 is slidably fitted with an opening and closing block 513. The opening and closing block 513 is set as a triangle with its apex facing upward. The bottom of the opening and closing block 513 is equipped with an L-shaped connecting rod 514. The longitudinal rod of the L-shaped connecting rod 514 passes through the outer wall of the connecting cylinder 502 and a beveled block 517 is installed at one end inside it. The beveled side of the beveled block 517 faces one side of the reciprocating block 515. The lower side of the reciprocating block 515 is arc-shaped and cooperates with the beveled side of the beveled block 517. A spring 516 is installed between the L-shaped connecting rod 514 and the outer wall of the connecting cylinder 502.

[0033] Specifically, when the scraper 504 moves toward the drain port 512 to scrape away impurities on the surface of the filter plate 501, the arc-shaped surface on the lower side of the reciprocating block 515 pushes the inclined block 517, causing the L-shaped connecting rod 514 to drive the opening and closing block 513 to move downward, opening the drain port 512. The scraped impurities fall into the collection box 10 at the bottom of the filter box 4 through the drain port 512. When the scraper 504 moves in the opposite direction, under the action of the spring 516, the opening and closing block 513 moves upward, closing the drain port 512 to prevent the plastic melt from flowing out of the drain port, so that the drain port 512 opens when the scraper 504 scrapes away impurities on the surface of the filter plate 501.

[0034] The above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, the present utility model is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present utility model, and all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present utility model.

Claims

1. A blown film extrusion screw structure, comprising a base (1), characterized in that: A conveying cylinder (2) is fixedly installed above the base (1). A feed hopper (3) connected to the conveying cylinder (2) is installed above the conveying cylinder (2). A filter box (4) is fixedly installed at the outlet of the conveying cylinder (2). A discharge nozzle (6) is fixedly installed at the outlet of the filter box (4). A filter assembly (5) is provided inside the filter box (4). A motor (7) located at one end of the conveying cylinder (2) is fixedly installed above the base (1). A conveying screw (8) rotatably engages with the inside of the conveying cylinder (2) is installed on the output shaft of the motor (7). A heating element (9) is installed on the inner wall of the conveying cylinder (2). A sludge collection box (10) is detachably installed at the bottom of the filter box (4). The filter assembly (5) includes a filter plate (501) with multiple filter holes installed inside the filter box (4). The middle of both side plates of the filter box (4) are in a through-slot state. The inner wall of the filter box (4) is equipped with a connecting cylinder (502) located on the periphery of the middle through-slot.

2. The extrusion screw structure for a blown film machine according to claim 1, characterized in that: The end of the conveying screw (8) is slidably fitted with a reciprocating rod (503). A scraper (504) is installed at one end of the reciprocating rod (503) near the filter plate (501). A square strip (505) is installed in the groove at the end of the conveying screw (8). A square groove (506) is opened at the end of the reciprocating rod (503) to slidably fit with the square strip (505).

3. The extrusion screw structure for a blown film machine according to claim 2, characterized in that: The end of the conveying screw (8) is equipped with a first helical bevel gear (507). The central shaft of the first helical bevel gear (507) is hollow. The inner wall of the filter box (4) is provided with a rotating groove (508). The inner wall of the rotating groove (508) is rotatably fitted with a rotating rod (509). The circumference of the rotating rod (509) is equipped with a second helical bevel gear (510) that meshes with the first helical bevel gear (507).

4. The extrusion screw structure for a blown film machine according to claim 3, characterized in that: The end of the rotating rod (509) is equipped with a rotating disk (511), and the reciprocating rod (503) is rotatably fitted with a reciprocating block (515). The reciprocating block (515) has an arc-shaped reciprocating groove (518) on the side near the rotating disk (511), and the rotating disk (511) is equipped with a connecting shaft (519) that cooperates with the arc-shaped reciprocating groove (518) on the side near the reciprocating block (515).

5. The extrusion screw structure for a blown film machine according to claim 4, characterized in that: The bottom of the connecting cylinder (502) near the filter plate (501) is equipped with a drain port (512), which is connected to the connecting cylinder (502) and has its opening facing downward.

6. The extrusion screw structure for a blown film machine according to claim 5, characterized in that: The inner wall of the bottom opening of the drain outlet (512) is slidably fitted with an opening and closing block (513). The opening and closing block (513) is a triangular block with its vertex facing upwards. An L-shaped connecting rod (514) is installed at the bottom of the opening and closing block (513).

7. The extrusion screw structure for a blown film machine according to claim 6, characterized in that: The longitudinal rod of the L-shaped connecting rod (514) passes through the outer wall of the connecting cylinder (502) and is fitted with a beveled block (517) at one end inside it. The beveled side of the beveled block (517) faces one side of the reciprocating block (515). The lower side of the reciprocating block (515) is arc-shaped and matches the beveled side of the beveled block (517). A spring (516) is installed between the L-shaped connecting rod (514) and the outer wall of the connecting cylinder (502).

Images