A plastic crushing device for BOPP film production

Abstract

The present invention relates to the technical field of plastic recycling and processing, and specifically to a plastic crushing device for BOPP film production, comprising a bracket, a shell and two crushing rollers. The shell is mounted on the bracket, and the two crushing rollers are arranged side by side in the shell. A plurality of air holes are evenly distributed on the crushing roller, and the crushing roller comprises a plurality of crushing sections and a plurality of cutting sections. The crushing section is provided with a crushing knife, and a plurality of cutting knives are arranged in the cutting section. A plastic crushing device for BOPP film production of the present invention is provided with a crushing roller. When a film is wound around the crushing roller, after the cutting knife extends out to cut the film, the film with a small volume that is not enough to be adsorbed by air pressure can fall off, while the film with a large volume that can still be adsorbed by air pressure will continue to rotate synchronously with the crushing roller, waiting for secondary cutting and crushing, thereby improving the crushing effect on the film and ensuring normal crushing.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic recycling and treatment, and particularly to a plastic crushing device for BOPP film production. Background Art

[0002] In the field of modern packaging materials, BOPP film is widely used in many industries due to its excellent optical properties, barrier properties, mechanical properties, printing adaptability and other characteristics.

[0003] The production of BOPP film originates from the melt processing of high molecular polypropylene. First, the melt is formed into sheets or thick films through an extruder, and then in a specific stretching machine, under precisely controlled temperature and speed conditions, it is stretched in two perpendicular directions, namely longitudinally and transversely, and combined with appropriate cooling, heat treatment or special processing techniques such as corona treatment and coating, and finally a film product that meets the requirements is formed. BOPP film belongs to thermoplastic plastics and can be reshaped after heating, so it has the characteristics of being recyclable and reusable. The waste generated during the production process can be crushed by a crushing device to make it have a more suitable shape for subsequent processing operations, such as better plasticizing and melting in an extruder.

[0004] However, due to the soft texture and strong stretching characteristics of BOPP film itself, during the crushing process, the film is extremely easy to wind around the crushing shaft. Once winding occurs, the rotational resistance of the crushing shaft will increase sharply, and its rotational speed will slow down accordingly. In severe cases, it may even cause the crushing shaft to jam, stopping the entire crushing device. This situation not only interrupts the production process, reduces production efficiency, but also may damage the mechanical structure of the crushing equipment, increasing the equipment maintenance cost and downtime. Summary of the Invention

[0005] The present invention provides a plastic crushing device for BOPP film production to solve the problem that in the existing crushing device, the plastic film is extremely easy to wind around the crushing shaft during the crushing process, affecting the normal progress of the crushing process.

[0006] A plastic crushing device for BOPP film production according to the present invention adopts the following technical solutions: A plastic crushing device for BOPP film production includes a bracket, a housing, and two crushing rollers; the housing is installed on the bracket, and a feed port and a discharge port are arranged on the housing in sequence in a first direction, the first direction is the vertical direction, and the feed port is located above the discharge port; the two crushing rollers are arranged side by side in the housing along a second direction, the crushing rollers are arranged along a third direction and can rotate around their own axes, the second direction and the third direction are both horizontal directions and are perpendicular to each other; a gas guide pipe is coaxially arranged in each crushing roller, and the gas guide pipe is fixedly connected to the bracket; a plurality of air holes are evenly distributed around the third direction on the crushing roller, an air passage is arranged around the third direction on the gas guide pipe, and the air passage is communicated with the outside through the air holes; in the first direction, the air passage is divided into an upper air passage and a lower air passage, the upper air passage is located above the lower air passage, the upper air passage and the lower air passage are not communicated with each other, the upper air passage can provide positive pressure to the air holes communicated with it, and the lower air passage can provide negative pressure to the air holes communicated with it; the crushing roller includes a plurality of crushing sections and a plurality of cutting sections arranged in sequence along the third direction, and the crushing sections and the cutting sections are alternately distributed in the third direction; the two crushing rollers are arranged in a staggered manner in the third direction, the crushing section of one crushing roller is arranged corresponding to the cutting section of the other crushing roller and meshes with each other; the crushing section is provided with crushing knives, and a plurality of cutting knives are arranged in the cutting section; the plurality of cutting knives can rotate with the cutting section and can extend and retract in a fourth direction, the fourth direction is the radial direction of the cutting section.

[0007] Further, whenever any cutting knife is arranged vertically downward, the distance that the cutting knife extends out of the cutting section in the fourth direction is greater than the distance that other cutting knives extend out of the cutting section in the fourth direction.

[0008] Further, a plurality of connecting components are fixedly arranged on the gas guide pipe, the plurality of connecting components are arranged in sequence along the third direction on the gas guide pipe, and the plurality of connecting components are arranged in one-to-one correspondence with the plurality of cutting sections; the plurality of cutting knives in each cutting section are evenly distributed around the third direction on the corresponding connecting component; the connecting component includes two connecting plates, the two connecting plates have the same structure and are arranged face to face in the third direction; both of the two connecting plates are provided with limiting grooves, a limiting plate is arranged in the limiting groove, and the plurality of cutting knives are all installed in the limiting groove and can slide around the third direction along the limiting plate; the limiting plate includes a first limiting section and a second limiting section; the first limiting section and the second limiting section are arranged in sequence and connected to each other around the third direction; both the first limiting section and the second limiting section are arc-shaped sections, the first limiting section is a minor arc, and the second limiting section is a major arc; the first limiting section is located below the second limiting section, and when the cutting knife slides along the first limiting section, the distance that the cutting knife extends out of the cutting section in the fourth direction is greater than the distance that the cutting knife extends out of the cutting section in the fourth direction when the cutting knife slides along the second limiting section.

[0009] Further, magnets are provided at one end of each cutting knife in contact with the limiting plate, and magnetic strips are wound around the outer peripheral wall surface of the limiting plate, and the magnetic strips can be attracted to the magnets.

[0010] Further, four cutting knives are provided in each cutting section, and the four cutting knives are evenly distributed around the third direction in the corresponding cutting section.

[0011] Further, the multiple air holes are divided into two groups. One group of air holes is opened on the crushing section, and there are multiple air holes on each crushing section. The other group of air holes is opened on the cutting section, and there are multiple air holes on each cutting section. There are multiple air channels, and the multiple air channels are sequentially arranged on the air guide pipe along the third direction. The multiple air channels are divided into two groups. One group of air channels is arranged in one-to-one correspondence with the multiple crushing sections, and the other group of air channels is arranged in one-to-one correspondence with the multiple cutting sections.

[0012] Further, a plurality of partition plates are provided on the end surface of the connecting plate, and the plurality of partition plates are evenly distributed around the third direction on the connecting plate. A flow limiting channel is defined between every two adjacent partition plates arranged around the third direction. The air holes opened on the cutting section are called first air holes, and the multiple flow limiting channels are arranged in one-to-one correspondence with the multiple first air holes and are communicated with each other.

[0013] Further, the connecting assembly further includes a connecting pipe. The connecting pipe and the two connecting plates are sequentially arranged in the third direction. The connecting pipe is fixedly connected to the two connecting plates. A plurality of through holes are opened on the connecting pipe around the third direction. The air holes opened on the crushing section are called second air holes, and the multiple through holes are arranged in one-to-one correspondence with the multiple second air holes and are communicated with each other.

[0014] Further, a plurality of telescopic grooves are opened on each cutting section, and the multiple cutting knives are arranged in one-to-one correspondence with the multiple telescopic grooves. Each cutting knife is installed in the corresponding telescopic groove and can move in the corresponding telescopic groove.

[0015] Further, an air pump is provided on the bracket. The air pump has two connectors. One is a negative pressure suction port, and the other is a positive pressure inflation port. A first air pipe is connected to the positive pressure inflation port through a first adapter, and the first air pipe is communicated with the upper air channel. A second air pipe is connected to the negative pressure suction port through a second adapter, and the second air pipe is communicated with the lower air channel.

[0016] The beneficial effects of the present invention are as follows: A plastic crushing device for BOPP film production according to the present invention is provided with crushing rollers. During the crushing process, when a film is wound around the crushing roller, multiple cutting blades rotating with the cutting section will cut the wound film along the fourth direction. Since the air duct remains stationary, as the crushing roller rotates self - sufficiently, the upper air duct will always provide positive pressure for the crushing roller rotating to this position. This setting can provide an upward acting force on the film through the airflow to assist the film in detaching from the crushing roller. And the lower air duct will always provide negative pressure for the crushing roller rotating to this position. This setting can provide an attractive force on the film through the airflow. Thus, after the cutting blade extends to cut the film, the film with a relatively small volume that is not sufficient to be adsorbed by the air pressure will fall off, while the film with a relatively large volume that can still be adsorbed by the air pressure will continue to rotate synchronously with the crushing roller and be driven by the crushing roller to rotate to the upper part again, waiting for secondary cutting and crushing, improving the crushing effect of the film. Moreover, the continuously flowing airflow will improve the air circulation inside the housing, assist in the heat dissipation of the crushing roller, prevent the film to be crushed from melting at high temperatures and sticking to the crushing roller, and ensure the normal progress of crushing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following - described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of the overall structure of an embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0019] Figure 2 It is a front view of the overall structure of an embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0020] Figure 3 It is Figure 2 a cross - sectional view along A - A in

[0021] Figure 4 It is Figure 3 a cross - sectional view along B - B in

[0022] Figure 5 It is Figure 4 an enlarged view of X in

[0023] Figure 6 It is a split view of a part of the mechanism of an embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0024] Figure 7Schematic diagram of the air duct of the embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0025] Figure 8 Schematic diagram of the connection assembly and cutting knife of the embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0026] Figure 9 Exploded view of the connection assembly and cutting knife of the embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0027] Figure 10 Front view of the connection assembly and cutting knife of the embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0028] Figure 11 is Figure 10 Cross-sectional view along C-C in

[0029] Figure 12 Side view of the connecting plate of the embodiment of a plastic crushing device for BOPP film production according to the present invention;

[0030] Figure 13 is Figure 12 Cross-sectional view along D-D in

[0031] In the figure: 100, bracket; 110, motor; 120, air pump; 200, housing; 210, feed inlet; 220, discharge outlet; 230, gear; 300, crushing roller; 301, air hole; 310, crushing section; 320, cutting section; 321, telescopic groove; 330, cutting knife; 400, air duct; 401, air guide plate; 410, air passage; 500, connection assembly; 510, connecting plate; 511, plate body; 512, connecting ring; 513, partition plate; 520, limiting groove; 530, limiting plate; 531, first limiting section; 532, second limiting section; 540, connecting pipe; 541, through hole. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] An embodiment of a plastic crushing device for BOPP film production according to the present invention is as shown in Figures 1 to 13 shown.

[0034] A plastic crushing device for BOPP film production, comprising a bracket 100, a housing 200 and two crushing rollers 300. The housing 200 is installed on the bracket 100. An inlet 210 and an outlet 220 are arranged on the housing 200 in sequence in a first direction. The first direction is the vertical direction, and the inlet 210 is located above the outlet 220. The two crushing rollers 300 are arranged in parallel in the housing 200 along a second direction. The crushing rollers 300 are arranged along a third direction and can rotate around their own axes. The second direction and the third direction are both horizontal directions and are perpendicular to each other. A gas guide pipe 400 is coaxially arranged in each crushing roller 300, and the gas guide pipe 400 is fixedly connected to the bracket 100. A plurality of air holes 301 are evenly distributed around the third direction on the crushing roller 300. An air passage 410 is arranged around the third direction on the gas guide pipe 400. The air passage 410 communicates with the outside through the air holes 301. In the first direction, the air passage 410 on the gas guide pipe 400 is divided into an upper air passage and a lower air passage. The upper air passage is located above the lower air passage, and the upper air passage and the lower air passage are not connected to each other. The upper air passage can provide positive pressure to the air holes 301 communicating with it, and the lower air passage can provide negative pressure to the air holes 301 communicating with it.

[0035] The crushing roller 300 includes a plurality of crushing sections 310 and a plurality of cutting sections 320 arranged in sequence along the third direction, and the crushing sections 310 and the cutting sections 320 are alternately distributed in the third direction. The two crushing rollers 300 are arranged in a staggered manner in the third direction. The crushing section 310 of one crushing roller 300 is correspondingly arranged with the cutting section 320 of the other crushing roller 300 and meshes with each other. The crushing section 310 is provided with crushing knives, and a plurality of cutting knives 330 are arranged in the cutting section 320. The plurality of cutting knives 330 can rotate with the cutting section 320 and can expand and contract in a fourth direction. The fourth direction is the radial direction of the cutting section 320.

[0036] Specifically, a motor 110 is arranged on the bracket 100, and two gears 230 are arranged on the housing 200. The two gears 230 are arranged in one-to-one correspondence with the two crushing rollers 300. Each gear 230 is coaxial with the corresponding crushing roller 300, and the crushing roller 300 extends out of the housing 200 along the third direction and is fixedly connected to the corresponding gear 230. The output end of the motor 110 is fixedly connected to one of the gears 230.

[0037] During use, when the motor 110 is started, it will drive the gear 230 fixedly connected to it to rotate. The rotation of the gear 230 will drive the other gear 230 meshing with it to rotate, so that the two crushing rollers 300 can rotate around their own axes respectively. As shown in the attached Figure 4 figure, the left crushing roller 300 rotates clockwise, and the right crushing roller 300 rotates counterclockwise.

[0038] In this embodiment, by setting up the crushing rollers 300, during use, the BOPP film (hereinafter simply referred to as the film) is fed into the housing 200 from one side of the feed port 210. When the film passes through the two crushing rollers 300, the film will be crushed under the action of the crushing knives on the crushing section 310, and the crushed film will be discharged from the discharge port 220.

[0039] During the crushing process, when the film winds around the crushing rollers 300, multiple cutting knives 330 rotating with the cutting section 320 will cut the wound film along the fourth direction. Since the air duct 400 does not move, as the crushing rollers 300 rotate self - sufficiently, the upper air duct will always provide positive pressure for the crushing roller 300 rotating to this position. This setting can provide an upward acting force on the film through the air flow to assist the film to break away from the crushing roller 300. And the lower air duct will always provide negative pressure for the crushing roller 300 rotating to this position. This setting can provide an attractive force on the film through the air flow. Thus, after the cutting knife 330 extends to cut the film, the film with a smaller volume that is not sufficient to be adsorbed by the air pressure can fall off, while the film with a larger volume that can still be adsorbed by the air pressure will continue to rotate synchronously with the crushing roller 300 and be driven by the crushing roller 300 to rotate to the upper part again, waiting for secondary cutting and crushing, improving the crushing effect of the film. And the continuously flowing air flow will improve the air circulation in the housing 200, assist the crushing roller 300 in heat dissipation, prevent the film to be crushed from melting at high temperature and sticking to the crushing roller 300, and ensure the normal progress of crushing.

[0040] In this embodiment, whenever any cutting knife 330 is set vertically downward, the distance that this cutting knife 330 extends out of the cutting section 320 in the fourth direction is greater than the distance that other cutting knives 330 extend out of the cutting section 320 in the fourth direction.

[0041] When the cutting section 320 drives the cutting knife 330 to rotate, since the film on the cutting section 320 and the cutting knife 330 are both in a relatively static state, by setting any cutting knife 330 vertically downward with the largest distance extending out of the cutting section 320, when the film and the cutting knife 330 rotate to this position, the cutting knife 330 can cut the most film. Thus, if there is film that can fall at this time, it can directly fall and be discharged.

[0042] In this embodiment, a plurality of connecting components 500 are fixedly arranged on the air duct 400. The plurality of connecting components 500 are arranged in sequence along the third direction on the air duct 400, and the plurality of connecting components 500 are arranged in one-to-one correspondence with the plurality of cutting sections 320. A plurality of cutting knives 330 in each cutting section 320 are evenly distributed around the third direction on the corresponding connecting component 500. The connecting component 500 includes two connecting plates 510. The two connecting plates 510 are arranged in sequence and fixedly connected in the third direction. The two connecting plates 510 have the same structure and are arranged face to face in the third direction. Limiting grooves 520 are formed on both of the two connecting plates 510. A limiting plate 530 is arranged in the limiting groove 520. A plurality of cutting knives 330 are all installed in the limiting groove 520 and can slide around the third direction along the limiting plate 530. The limiting plate 530 includes a first limiting section 531 and a second limiting section 532. The first limiting section 531 and the second limiting section 532 are arranged in sequence and connected to each other around the third direction. Both the first limiting section 531 and the second limiting section 532 are arc-shaped sections. The first limiting section 531 is a minor arc, and the second limiting section 532 is a major arc. The first limiting section 531 is located below the second limiting section 532. When the cutting knife 330 slides along the first limiting section 531, the distance that the cutting knife 330 extends out of the cutting section 320 in the fourth direction is greater than the distance that the cutting knife 330 extends out of the cutting section 320 in the fourth direction when the cutting knife 330 slides along the second limiting section 532.

[0043] Specifically, the second limiting section 532 is an arc-shaped structure that is convex in the middle and concave at both ends. The distance from the first limiting section 531 to the central axis of the connecting plate 510 along the third direction in the fourth direction is greater than the distance from the second limiting section 532 to the central axis of the connecting plate 510 along the third direction in the fourth direction. Thus, when the cutting knife 330 slides along the first limiting section 531, the distance that the cutting knife 330 extends out of the cutting section 320 in the fourth direction is greater than the distance that the cutting knife 330 extends out of the cutting section 320 in the fourth direction when the cutting knife 330 slides along the second limiting section 532.

[0044] The connecting plate 510 includes a plate body 511 and a connecting ring 512. The plate body 511 and the connecting ring 512 are arranged in sequence in the third direction. The limiting plate 530 is located between the plate body 511 and the connecting ring 512. The limiting groove 520 is defined by the plate body 511, the connecting ring 512, and the limiting plate 530. The cutting knife 330 has two knife arms. The two knife arms are arranged in one-to-one correspondence with the limiting grooves 520 of the two connecting plates 510. Each knife arm is installed in the corresponding limiting groove 520.

[0045] In this embodiment, a magnet is provided at one end of each cutter 330 in contact with the limiting plate 530. A magnetic strip is wound around the outer peripheral wall surface of the limiting plate 530, and the magnetic strip can be attracted to the magnet. Thus, when the cutting section 320 rotates and drives the corresponding cutter 330 to rotate, one end of the cutter 330 in contact with the limiting plate 530 can always slide along the limiting plate 530 and is limited by the limiting plate 530, realizing the expansion and contraction of the cutter 330 in the fourth direction.

[0046] In this embodiment, four cutters 330 are provided in each cutting section 320, and the four cutters 330 are evenly distributed around the third direction in the corresponding cutting section 320. That is, the four cutters 330 are perpendicular to each other.

[0047] Specifically, a plurality of expansion slots 321 are formed in each cutting section 320, and the plurality of expansion slots 321 are all through slots arranged in the fourth direction. The plurality of cutters 330 are arranged in one-to-one correspondence with the plurality of expansion slots 321, and each cutter 330 is installed in a corresponding expansion slot 321 and can move in the corresponding expansion slot 321.

[0048] In this embodiment, by providing the connection assembly 500, during use, as the crushing roller 300 rotates, the cutting section 320 on the crushing roller 300 will drive the cutter 330 thereon to rotate. Since the connection assembly 500 is fixedly arranged, when the cutter 330 slides along the limiting plate 530, the length of the cutter 330 extending out will continuously change with the arcs of the first limiting section 531 and the second limiting section 532. Refer to the attached Figure 13 As shown, when the cutter 330 slides along the first limiting section 531, the distance that the cutter 330 extends out of the cutting section 320 in the fourth direction is greater than the distance that the cutter 330 extends out of the cutting section 320 in the fourth direction when the cutter 330 slides along the second limiting section 532.

[0049] Since four cutters 330 are provided in each cutting section 320, when one cutter 330 is arranged vertically downward, the other three cutters 330 are all on the second limiting section 532. That is, whenever any cutter 330 is arranged vertically downward, the distance that the cutter 330 extends out of the cutting section 320 in the fourth direction is greater than the distance that the other cutters 330 extend out of the cutting section 320 in the fourth direction. That is, by making the distance that the cutter 330 extends out of the cutting section 320 the largest when any cutter 330 is arranged vertically downward, when the film rotates to this position, the cutter 330 can cut the most film, and thus if there is film that can fall at this time, it can directly fall and be discharged.

[0050] In this embodiment, a plurality of air holes 301 are divided into two groups. One group of air holes 301 is formed on the crushing section 310, and there are multiple air holes 301 on each crushing section 310. The other group of air holes 301 is formed on the cutting section 320, and there are multiple air holes 301 on each cutting section 320.

[0051] A plurality of air ducts 410 are provided. The plurality of air ducts 410 are sequentially arranged on the air guide pipe 400 along the third direction. The plurality of air ducts 410 are divided into two groups. One group of air ducts 410 is arranged in one-to-one correspondence with the plurality of crushing sections 310, and the other group of air ducts 410 is arranged in one-to-one correspondence with the plurality of cutting sections 320.

[0052] Specifically, there are a plurality of air guide plates 401 in the air guide pipe 400. The air guide plates 401 are evenly distributed in the air guide pipe 400 around the third direction. The air duct 410 is defined by every two adjacent air guide plates 401 arranged around the third direction.

[0053] By respectively forming air holes 301 on the cutting section 320 and the crushing section 310 and making them communicate with the correspondingly arranged air ducts 410, it can be ensured that there is gas on each cutting section 320 and each crushing section 310, realizing the uniform distribution of gas.

[0054] In this embodiment, a plurality of partition plates 513 are arranged on the end surface of the connecting plate 510. The plurality of partition plates 513 are evenly distributed on the connecting plate 510 around the third direction. A flow limiting channel is defined between every two adjacent partition plates 513 arranged around the third direction. The air holes 301 formed on the cutting section 320 are called first air holes. The plurality of flow limiting channels are arranged in one-to-one correspondence with the plurality of first air holes and are communicated with each other. The air duct 410 correspondingly arranged with the cutting section 320 is communicated with the first air holes through the flow limiting channels.

[0055] Furthermore, the connecting assembly 500 further includes a connecting pipe 540. The connecting pipe 540 and the two connecting plates 510 are sequentially arranged in the third direction. The connecting pipe 540 is fixedly connected to the two connecting plates 510. A plurality of through holes 541 are formed on the connecting pipe 540 around the third direction. The air holes 301 formed on the crushing section 310 are called second air holes. The plurality of through holes 541 are arranged in one-to-one correspondence with the plurality of second air holes and are communicated with each other. The air duct 410 correspondingly arranged with the crushing section 310 is communicated with the second air holes through the through holes 541.

[0056] In this embodiment, a first air hole is formed in the cutting section 320, and the air passage 410 on the air guide pipe 400 is communicated with the first air hole through a flow limiting passage. When in use, the gas flowing out from the air passage 410 of the air guide pipe 400 will first be shunted through the corresponding flow limiting passage, and then discharged from the first air hole corresponding to the flow limiting passage. Similarly, a second air hole is formed in the crushing section 310, and the air passage 410 on the air guide pipe 400 is communicated with the second air hole through a through hole 541. When in use, the gas flowing out from the air passage 410 of the air guide pipe 400 will first be shunted through the corresponding air hole 301, and then discharged from the second air hole corresponding to the through hole 541.

[0057] In this embodiment, eight air guide plates 401 are provided, and the eight air guide plates 401 define eight air passages 410, among which, four are upper air passages and four are lower air passages. Eight partition plates 513 are provided, and the eight partition plates 513 define eight flow limiting passages. Each cutting section 320 is provided with eight first air holes around the third direction, and the eight first air holes are arranged in one-to-one correspondence with the eight flow limiting passages. The connecting pipe 540 is provided with eight through holes 541 around the third direction, and each crushing section 310 is provided with eight second air holes, and the eight second air holes are arranged in one-to-one correspondence with the eight through holes 541.

[0058] In this embodiment, an air pump 120 is provided on the bracket 100. The air pump 120 adopts an R400-VC positive and negative pressure dual-purpose oil-free vacuum pump. The air pump 120 has two connectors, one of which is a negative pressure suction port and the other is a positive pressure air injection port. A first air pipe is connected to the positive pressure air injection port through a first adapter, and the first air pipe is communicated with the upper air passage. A second air pipe is connected to the negative pressure suction port through a second adapter, and the second air pipe is communicated with the lower air passage.

[0059] Alternatively, an air extraction pump and an air inflation pump are provided on the bracket 100. A first air pipe is connected to the air inflation pump through a first adapter, and the first air pipe is arranged corresponding to the upper air passage. A second air pipe is connected to the air extraction pump through a second adapter, and the second air pipe is arranged corresponding to the lower air passage.

[0060] Specifically, both the first air pipe and the second air pipe are provided with four. The four first air pipes are arranged in one-to-one correspondence with the four upper air passages, and the four second air pipes are arranged in one-to-one correspondence with the four second air passages 410.

[0061] In this embodiment, by providing the air pump 120, the air pump 120 is used to provide positive pressure for the upper air passage and negative pressure for the lower air passage.

[0062] Combined with the above embodiments, the specific working process is as follows:

[0063] When in use, the motor 110 is started, and the motor 110 is used to drive the two crushing rollers 300 to rotate around their respective axes. Refer to the appendixFigure 4 As shown, the crushing roller 300 on the left rotates clockwise, and the crushing roller 300 on the right rotates counterclockwise.

[0064] Then, the BOPP film is fed into the housing 200 from one side of the feed port 210. The BOPP film is hereinafter simply referred to as the film. When the film passes through the two crushing rollers 300, the film will be crushed under the action of the crushing knives on the crushing section 310, and the crushed film will be discharged from the discharge port 220. At the same time, the air pump 120 is started to supply air to the air duct 400.

[0065] During the crushing process, when the film is wound around the crushing roller 300, with the rotation of the crushing roller 300, the cutting section 320 on the crushing roller 300 will drive the cutting knife 330 thereon to rotate. Since the connecting assembly 500 is fixedly arranged, when the cutting knife 330 slides along the limiting plate 530, the length of the cutting knife 330 extending out will continuously change with the arcs of the first limiting section 531 and the second limiting section 532. See the appendix Figure 13 As shown, when the cutting knife 330 slides along the first limiting section 531, the distance that the cutting knife 330 extends out of the cutting section 320 in the fourth direction is greater than the distance that the cutting knife 330 extends out of the cutting section 320 in the fourth direction when the cutting knife 330 slides along the second limiting section 532.

[0066] That is, the multiple cutting knives 330 rotating with the cutting section 320 will cut the wound film in the fourth direction, and when any cutting knife 330 is vertically downward, the distance extending out of the cutting section 320 is the largest. Thus, when the film rotates to this position, the cutting knife 330 can cut the most film, and thus if there is film that can fall at this time, it can directly fall and be discharged.

[0067] And since the air duct 400 does not move, with the rotation of the crushing roller 300, the upper air duct will always provide positive pressure for the crushing roller 300 rotating to this position. This setting can provide an upward acting force on the film through the air flow to assist the film in separating from the crushing roller 300. And the lower air duct will always provide negative pressure for the crushing roller 300 rotating to this position. This setting can provide an attractive force on the film through the air flow. Thus, after the cutting knife 330 extends out to cut the film, the film with a smaller volume that is not sufficient to be adsorbed by the air pressure can fall off, while the film with a larger volume that can still be adsorbed by the air pressure will continue to rotate synchronously with the crushing roller 300 and be driven by the crushing roller 300 to rotate to the upper part again, waiting for secondary cutting and crushing, improving the crushing effect of the film. And the continuously flowing air flow will improve the air circulation in the housing 200, assist the crushing roller 300 in heat dissipation, prevent the film to be crushed from melting at high temperature and sticking to the crushing roller 300, and ensure the normal progress of crushing.

[0068] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A plastic crushing device for BOPP film production, characterized in that: It comprises a bracket, a shell and two crushing rollers; the shell is mounted on the bracket, and a feed port and a discharge port are provided on the shell in sequence in a first direction, the first direction is a vertical direction, and the feed port is located above the discharge port; the two crushing rollers are arranged in parallel along a second direction in the shell, the crushing rollers are arranged along a third direction and can rotate around their own axes, and the second direction and the third direction are both horizontal directions and perpendicular to each other; an air guide tube is coaxially arranged in each crushing roller, and the air guide tube is fixedly connected to the bracket; a plurality of air holes are evenly distributed on the crushing roller around the third direction, and an airway is provided on the air guide tube around the third direction, and the airway is connected to the outside through the air holes; The airway is divided into an upper airway and a lower airway in a first direction, the upper airway is located above the lower airway, the upper airway and the lower airway are not connected to each other, the upper airway can provide positive pressure to the air holes connected to it, and the lower airway can provide negative pressure to the air holes connected to it; the crushing roller includes a plurality of crushing sections and a plurality of cutting sections arranged in sequence along the third direction, and the crushing sections and the cutting sections are alternately distributed in the third direction; the two crushing rollers are staggered in the third direction, the crushing section of one crushing roller is arranged correspondingly to the cutting section of the other crushing roller and meshes with each other; the crushing section is provided with a crushing knife, and the cutting section is provided with a plurality of cutting knives; The plurality of cutters can rotate with the cutting section and can be extended and retracted in a fourth direction, which is the radial direction of the cutting section; a plurality of connecting components are fixedly arranged on the air guide tube, and the plurality of connecting components are sequentially arranged on the air guide tube along a third direction, and the plurality of connecting components are arranged one by one in correspondence with the plurality of cutting sections; the plurality of cutters in each cutting section are evenly distributed around the third direction on the corresponding connecting components; the connecting component includes two connecting plates, which have the same structure and are arranged face to face in the third direction; both connecting plates have limit grooves, and the limit grooves are provided with limit plates, and the plurality of Each cutter is installed in a limit groove and can slide along the limit plate around a third direction; the limit plate includes a first limit section and a second limit section; the first limit section and the second limit section are arranged in sequence around the third direction and are connected to each other; the first limit section and the second limit section are both arc sections, the first limit section is an inferior arc, and the second limit section is a superior arc; the first limit section is located below the second limit section, and when the cutter slides along the first limit section, the distance that the cutter extends out of the cutting section in the fourth direction is greater than the distance that the cutter extends out of the cutting section in the fourth direction when the cutter slides along the second limit section.

2. The plastic crushing device for BOPP film production according to claim 1, characterized in that: Whenever any cutter is arranged vertically downward, the distance that the cutter extends out of the cutting section in the fourth direction is greater than the distance that the other cutters extend out of the cutting section in the fourth direction.

3. The plastic crushing device for BOPP film production according to claim 1, characterized in that: One end of each cutter in contact with the limiting plate is provided with a magnet, and a magnetic strip is wound around the outer peripheral wall surface of the limiting plate, and the magnetic strip can be attracted to the magnet.

4. The plastic crushing device for BOPP film production according to claim 3, characterized in that: Four cutters are arranged in each cutting section, and the four cutters are evenly distributed around the third direction in the corresponding cutting section.

5. The plastic crushing device for BOPP film production according to claim 1, characterized in that: The multiple air holes are divided into two groups, one group of air holes is opened on the crushing section, and each crushing section has multiple air holes, and the other group of air holes is opened on the cutting section, and each cutting section has multiple air holes; multiple air passages are provided, and the multiple air passages are sequentially arranged along the third direction on the air guide tube, and the multiple air passages are divided into two groups, one group of air passages is arranged corresponding to the multiple crushing sections one by one, and the other group of air passages is arranged corresponding to the multiple cutting sections one by one.

6. The plastic crushing device for BOPP film production according to claim 5, characterized in that: A plurality of partitions are arranged on the end surface of the connecting plate, and the plurality of partitions are evenly distributed on the connecting plate around a third direction, and a flow limiting channel is defined between every two adjacent partitions arranged around the third direction; the air hole opened on the cutting section is called a first air hole, and the plurality of flow limiting channels and the plurality of first air holes are arranged one by one and are interconnected.

7. The plastic crushing device for BOPP film production according to claim 6, characterized in that: The connecting assembly also includes a connecting pipe, which and two connecting plates are arranged in sequence in a third direction, the connecting pipe is fixedly connected to the two connecting plates, and a plurality of through holes are opened on the connecting pipe around the third direction; the air holes opened on the crushing section are called second air holes, and the plurality of through holes and the plurality of second air holes are arranged one by one and are interconnected.

8. The plastic crushing device for BOPP film production according to claim 1, characterized in that: Each cutting section is provided with a plurality of telescopic slots, and a plurality of cutters are arranged correspondingly to the plurality of telescopic slots. Each cutter is installed in the corresponding telescopic slot and can move in the corresponding telescopic slot.

9. The plastic crushing device for BOPP film production according to claim 1, characterized in that: An air pump is arranged on the bracket, and the air pump has two joints, one of which is a negative pressure suction port, and the other is a positive pressure inflation port. The positive pressure inflation port is connected to a first air pipe through a first adapter, and the first air pipe is connected to the upper airway. The negative pressure suction port is connected to a second air pipe through a second adapter, and the second air pipe is connected to the lower airway.

Images