Plastic granulator

Abstract

The utility model discloses a plastic granulator, which comprises a granulating die, the granulating die is provided with a main flow channel and a plurality of branch flow channels, all the branch flow channels are communicated with the main flow channel, the branch flow channels are connected with a discharge pipe, the discharge pipe is provided with a piston port in the axis direction of the discharge pipe, and the discharge pipe is provided with a notch in the orthogonal direction of the axis of the discharge pipe. Any two notches have mutually staggered orientations; the water tank cover is close to the discharging pipe and connected to the pelletizing mold, and the water tank cover is provided with a water inlet end and a water outlet end; the piston mechanism comprises a driving device, a movable part and a plurality of piston heads, the piston heads are connected to the movable part, the driving device drives the movable part to do linear reciprocating motion, all the piston heads and all the piston openings are arranged in a one-to-one correspondence mode, the piston heads are connected to the discharging pipe in a sealed mode, and the moving paths of the piston heads cover the corresponding notches. The water ring granulator disclosed by the utility model can be improved on the basis of the existing water ring granulator, and is specially used for granulating high-flowability plastic, so as to overcome the existing technical obstacles.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic processing, and particularly relates to a plastic granulator. Background Art

[0002] The water ring granulator is a relatively widely used granulating device on an extruder and is applicable to most plastic processing, such as materials like PVC, PE, and PPR. The existing water ring granulator consists of a centrifugal dehydrator, a cooling water tank, a granulating cart, a water ring cover, a conveying pipeline, a cutting knife assembly, and a granulating motor. The whole set of system is installed at the end of the extruder and is connected to the die head of the extruder, and the axis of the granulator coincides with the axis of the extruder. The water ring cover, the cutting knife, the granulating motor, the circulating water pump, the heat exchanger, and the operation box are all installed on the granulating cart, and the granulating cart can move on the guide rail. During operation, the granulating cart is pushed forward to make the water ring cover closely abut against the die head of the extruder. The material is extruded through the discharge hole of the die head, and then the cutting knife is driven by the granulating motor to rotate to cut the material into particles. The particles are cooled in the cooling water tank and fall into the conveying pipeline at the bottom of the water ring cover, and are conveyed to the downstream equipment by the external centrifugal water pump through water pressure.

[0003] However, for PP plastics, due to the good fluidity of the PP melt, when the granulating motor drives the cutting knife to perform high-speed granulation, the insufficiently cooled PP melt is likely to adhere to the cutting knife and bond with the PP melt at the next working station, thus fusing into large-sized particles, which does not meet the shipping requirements of plastic particles.

[0004] Therefore, the existing PP plastics are generally processed by a conventional slitting machine and shipped in the form of long strips. However, the long-strip particles will significantly reduce the volume-weight ratio during plastic packaging, so the loading capacity of PP plastic particles is less than that of other plastic particles, resulting in a consistently high transportation cost for PP plastic particles. Summary of the Utility Model

[0005] The utility model aims to provide a plastic granulator that can granulate plastics with high fluidity.

[0006] The plastic granulator according to the first aspect embodiment of the utility model includes:

[0007] A granulating die, which is provided with a main runner and a plurality of sub-runners. All the sub-runners communicate with the main runner. Each sub-runner is connected with an outwardly extending discharge pipe. Each discharge pipe is provided with a piston port in its own axial direction, and each discharge pipe is provided with a cut in the direction orthogonal to its own axis. The orientations of any two cuts are offset from each other;

[0008] A water tank cover, which is close to the discharge pipe and connected to the granulating die. The water tank cover is provided with a water inlet end and a water outlet end;

[0009] A piston mechanism, which includes a driving device, a movable part, and a plurality of piston heads. All the piston heads are connected to the movable part. The driving device drives the movable part to perform a linear reciprocating motion. All the piston heads and all the piston ports are arranged in one-to-one correspondence respectively. The piston head is sealingly connected to the corresponding discharge pipe, and the moving path of the piston head covers the corresponding notch.

[0010] The plastic granulator according to the embodiment of the present invention has at least the following beneficial effects: The main runner of the granulation die is docked with the die head of the extruder, so that the extruder can convey the plastic molten fluid to the granulation die. During granulation, the driving device drives the piston head to move towards the direction close to the sub-runner. At this time, the runner of the granulation die is under positive pressure, and the plastic molten fluid is extruded to flow out from the notch. After the piston head passes through the notch, it will cut off the plastic molten fluid. At this time, the plastic molten fluid enters the cooling water body in the water tank cover in a granular form. Since any two notches have misaligned orientations, it is possible to avoid adhesion between any two plastic particles in the short time after leaving the discharge pipe, thus achieving the effect of distinct particles. The cooled plastic particles are gathered towards the water outlet end under the drive of the water flow; when the driving device drives the piston head to reset, since the runner was under positive pressure before, the plastic molten fluid will quickly fill the entire discharge pipe under the action of the positive pressure, waiting for the next granulation action; The present invention can be modified on the basis of the existing water-ring granulator and is specifically used for granulating high-fluidity plastics to overcome the existing technical obstacles.

[0011] According to some embodiments of the present invention, in order to facilitate processing the plastic molten fluid into granular form, the size of the notch on the outer wall of the discharge pipe is larger than the size of the notch on the inner wall of the discharge pipe.

[0012] According to some embodiments of the present invention, the vertical wall of the notch is an incomplete spherical surface, so that the processed plastic particles have an arc surface, in order to improve the volume-weight ratio of the plastic particles during packaging.

[0013] According to some embodiments of the present invention, in order to facilitate cleaning, the granulation die is detachably connected to the water tank cover.

[0014] According to some embodiments of the present invention, since the granulation die and the water tank cover are detachable, when assembling the two, in order to facilitate the one-to-one docking of all the piston heads and all the piston ports, a slide rail is further included. Both the water tank cover and the granulation die are slidably connected to the slide rail.

[0015] According to some embodiments of the present utility model, specifically, the pelletizing die includes a first template and a second template connected to each other. The main runner is provided on the first template, the sub-runners are provided on the second template, the second template is connected to the water tank cover, and the first template is connected to an external extruder die head.

[0016] According to some embodiments of the present utility model, the second template is connected with a diversion cone extending to the main runner, and the size of the diversion cone gradually increases from the direction of the first template to the second template. The setting of the diversion cone is to facilitate the diversion of the plastic molten fluid to each sub-runner.

[0017] According to some embodiments of the present utility model, in order to achieve standardized production, all the sub-runners are circumferentially evenly distributed around the axis of the diversion cone, so that all the sub-runners maintain the same working conditions.

[0018] According to some embodiments of the present utility model, specifically, the driving device is installed on the water tank cover, and the driving device includes a cylinder, a crank-slider device, an electric push rod or a gear-rack device.

[0019] According to some embodiments of the present utility model, the plastic pelletizing machine further includes a circulating water pump, and the circulating water pump is respectively connected to the water inlet end and the water outlet end to realize the recycling of the water in the water tank cover.

[0020] The additional aspects and advantages of the present utility model will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0022] Figure 1 is a three-dimensional structural schematic diagram of the plastic pelletizing machine provided by the embodiment of the present utility model;

[0023] Figure 2 is Figure 1 the top view of the plastic pelletizing machine shown;

[0024] Figure 3 is Figure 2 the sectional view of the plastic pelletizing machine shown along the A-A section line;

[0025] Figure 4 is a three-dimensional structural schematic diagram of the discharge pipe provided by the embodiment of the present utility model.

[0026] In the accompanying drawings: 100 - pelletizing die, 200 - water tank cover, 300 - piston mechanism, 110 - first template, 120 - second template, 111 - main runner, 121 - sub - runner, 130 - flow - guiding cone, 122 - groove, 400 - discharge pipe, 410 - piston port, 420 - notch, 201 - water storage cavity, 210 - water inlet end, 220 - water outlet end, 310 - driving device, 320 - movable part, 330 - piston head, 510 - positioning recess, 520 - positioning protrusion. Detailed implementation manners

[0027] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0028] In the description of the present utility model, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0029] In the description of the present utility model, the meaning of several is one or more, the meaning of a plurality is more than two, understand greater than, less than, exceeding, etc. as not including the present number, and understand above, below, within, etc. as including the present number. If the first and the second are described only for the purpose of distinguishing technical features, they should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0030] In the description of the present utility model, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solution.

[0031] As Figures 1 to 3As shown in the figure, the plastic pelletizing machine according to the first aspect embodiment of the present utility model includes a pelletizing die 100, a water tank cover 200, a piston mechanism 300, and a circulating water pump (not shown in the attached drawings). The pelletizing die 100 includes a first template 110 and a second template 120. The first template 110 and the second template 120 are connected by a threaded connector. The first template 110 is provided with a main runner 111, and the second template 120 is provided with a plurality of sub-runners 121 communicating with the main runner 111. The pelletizing die 100 is connected to an external extruder die head through the first template 110, and the pelletizing die 100 is connected to the water tank cover 200 through the second template 120. The plastic molten fluid in the extruder die head is unidirectionally pushed to the main runner 111 of the first template under the conveyance of a feeding screw. Subsequently, the plastic molten fluid in the main runner 111 is diverted to each sub-runner 121 and finally enters the cooling water body in the water tank cover 200 for cooling and hardening.

[0032] In order to facilitate guiding the plastic molten fluid in the main runner 111 to each sub-runner 121, the second template 120 is connected with a guiding cone 130 extending into the main runner 111. The guiding cone 130 can be selected as a cone. The size of the guiding cone 130 gradually increases from the direction of the first template 110 to the second template 120. And the second template 120 is provided with a trough 122 beside the guiding cone 130. All the sub-runners 121 are arranged at the lower position of the trough 122. During operation, the plastic molten fluid in the main runner 111 is guided along the inclined surface of the guiding cone 130 after contacting the guiding cone 130. The plastic molten fluid is then diverted to each sub-runner 121 after entering the trough 122. Since each sub-runner 121 communicates with the trough 122, the flow rate of each sub-runner 121 remains consistent.

[0033] Furthermore, in order to achieve standardized production, all the sub-runners 121 are circumferentially evenly distributed around the axis of the guiding cone 130, so that all the sub-runners 121 maintain the same working conditions. The above setting also facilitates the machining of the second template 120 using machining equipment. The machining process of the second template 120 by the machining equipment is as follows: First, the second template 120 is fixed on the rotating chuck of the machining equipment. After the rotating chuck positions and fixes the second template 120, a drill bit processes the first sub-runner 121 on the second template 120. Subsequently, the drill bit returns to its original position, and the rotating chuck drives the second template 120 to rotate at a specific angle. The drill bit is used again to process the second sub-runner 121, and so on, until all the sub-runners 121 are finally processed.

[0034] In addition, the second template 120 is connected with an outwardly extending discharge pipe 400 at the end of each sub-runner 121. The discharge pipe 400 can be selected as a round pipe. The structure of the discharge pipe 400 is as Figure 4As shown, one end thereof is connected to the runner 121, and the other end thereof is provided with a piston port 410 in the direction of its own axis. The discharge pipe 400 is provided with a notch 420 in the orthogonal direction of its own axis, and the notch 420 is located in the middle of the discharge pipe 400. It should be noted that the notches 420 of any two discharge pipes 400 have misaligned orientations to ensure that the extension lines of any two notches 420 do not intersect. In this embodiment, all the discharge pipes 400 together form an annular region, and each notch 420 faces outward along the diameter direction of the annular region.

[0035] Furthermore, the notch 420 has a special shape. The size of the notch 420 on the outer wall of the discharge pipe 400 is larger than the size of the notch 420 on the inner wall of the discharge pipe 400. That is to say, the size of the notch 420 gradually increases from the inside of the discharge pipe 400 to the outside of the discharge pipe 400, so that when the molten plastic fluid flows out from the notch 420, it can form granular rather than strip-shaped.

[0036] Even further, since the discharge pipe 400 has a certain thickness, the notch 420 has a vertical wall corresponding to the thickness. At this time, the vertical wall of the notch 420 is a defective spherical surface, and this defective spherical surface is a three-dimensional figure obtained by cutting a spherical surface through two parallel lines, so that the processed plastic particles have an arc surface to improve the volume-weight ratio of the plastic particles during packaging and effectively reduce the transportation cost.

[0037] As Figures 1 to 3 shown, the water tank cover 200 has a water storage chamber 201, and all the discharge pipes 400 extend into the water storage chamber 201. The side wall of the water tank cover 200 is provided with an inlet end 210 and an outlet end 220 arranged oppositely. The inlet end 210 and the outlet end 220 are an inlet pipe and an outlet pipe respectively. The circulation pump is respectively connected to the inlet pipe and the outlet pipe through pipelines to realize the recycling of the water body in the water tank cover 200. Since the present utility model does not improve the water circuit of the plastic granulator, the water circuit structure of the plastic granulator can follow the prior art, so the detailed description of the water circuit structure is omitted herein.

[0038] As Figure 3As shown in the figure, the piston mechanism 300 includes a driving device 310, a movable part 320, and a plurality of piston heads 330. All the piston heads 330 are connected to the movable part 320. The driving device 310 is installed outside the water tank cover 200. The driving device 310 passes through the water tank cover 200 and drives the movable part 320 to perform a linear reciprocating motion, thereby driving all the piston heads 330 to perform a linear reciprocating motion. The number of the piston heads 330 is consistent with the number of the discharge pipes 400. All the piston heads 330 and all the piston ports 410 are arranged in one-to-one correspondence respectively. All the piston heads 330 are hermetically connected to the corresponding discharge pipes 400, that is, the outer diameter of the piston head 330 is equal to the inner diameter of the discharge pipe 400. The moving paths of all the piston heads 330 cover the corresponding cutouts 420. Since the piston head 330 blocks the piston port 410 of the discharge pipe 400, the plastic molten fluid in the discharge pipe 400 can only flow out from the cutout 420.

[0039] In this embodiment, the driving device 310 can be selected as a cylinder. However, in some other embodiments, the driving device 310 can also be a crank-slider device, an electric push rod, a gear-rack device, or other devices. As long as the driving device 310 can realize the linear reciprocating motion of the movable part 320, no matter what structure the driving device 310 is, it belongs to the protection scope of the present utility model.

[0040] With the above structure, during pelletizing, the driving device 310 drives the piston head 330 to move towards the direction close to the diversion channel 121. Under the combined action of the piston head 330 and the feeding screw, the flow channel of the pelletizing die 100 is under positive pressure. The plastic molten fluid is extruded to flow out from the cutout 420. After the piston head 330 passes through the cutout 420, it will cut off the plastic molten fluid. At this time, the plastic molten fluid enters the cooling water body in the water tank cover 200 in a granular state. Since the orientations of any two cutouts 420 are mutually staggered, it is possible to avoid the adhesion of any two plastic particles within a short time after leaving the discharge pipe 400, thereby achieving the effect of distinct particles. The cooled plastic particles are gathered towards the water outlet end 220 under the drive of the water flow. When the driving device 310 drives the piston head 330 to reset, since the flow channel was under positive pressure before, the plastic molten fluid will quickly fill the entire discharge pipe 400 under the action of the positive pressure, waiting for the next pelletizing action. The present utility model can be modified on the basis of the existing water ring pelletizing machine and is specifically used for pelletizing high-fluidity plastics to overcome the existing technical obstacles.

[0041] It should be noted that when the plastic particles leave the water tank cover under the drive of the water flow, a collection box is provided at the downstream position of the water flow. A filter screen is provided in the collection box to intercept the plastic particles. After shutdown, take out the collection box and spread the plastic particles in the collection box on a dryer for drying to obtain dry plastic particles.

[0042] In some embodiments of the present utility model, after shutdown or before changing the plastic material to be cut, it is necessary to clean the water tank cover 200 and the granulation die 100 to avoid cross-contamination between different plastic materials. For the convenience of cleaning, the granulation die 100 is detachably connected to the water tank cover 200, and the two are connected by metal latches (not shown in the attached drawings). When it is necessary to connect the granulation die 100 and the water tank cover 200, first dock the second template 120 of the granulation die 100 with the water tank cover 200, and then lock a plurality of metal latches between the two; when it is necessary to separate the granulation die 100 and the water tank cover 200, first unlock all the metal latches, and then separate the water tank cover 200 and the second template 120.

[0043] Furthermore, in order to better adjust the positions of the water tank cover 200 and the granulation die 100, slide rails (not shown in the attached drawings) are provided below the two. The second template 120 of the granulation die 100 and the water tank cover 200 are both connected with sliders (not shown in the attached drawings) that are slidably connected to the slide rails, and only the degrees of freedom of the water tank cover 200 and the granulation die 100 in the length direction of the slide rails are retained. When the water tank cover 200 and the granulation die 100 are assembled, since only the degrees of freedom of the two in the length direction of the slide rails are retained, all the piston heads 330 and all the piston ports 410 can satisfy the one-to-one docking relationship, so as to eliminate the centering operation of the piston heads 330 and the piston ports 410.

[0044] Of course, in addition to the above embodiments, a positioning recess 510 may be provided on one of the granulation die 100 and the water tank cover 200, and a positioning protrusion 520 that is matingly connected to the positioning recess 510 may be provided on the other of the two. The number of the positioning protrusions 520 and the positioning recesses 510 is at least two. When the water tank cover 200 and the granulation die 100 are assembled, as long as the positioning protrusion 520 is aligned with the positioning recess 510, the one-to-one docking relationship between all the piston heads 330 and all the piston ports 410 can be satisfied.

[0045] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments, and various changes can be made without departing from the gist of the present utility model within the knowledge scope of those of ordinary skill in the art.

Claims

1. Plastic pelletizer, characterized in that, include: A pelletizing die (100) is provided with a main flow channel (111) and a plurality of branch flow channels (121), all of the branch flow channels (121) are connected to the main flow channel (111), each of the branch flow channels (121) is connected to a discharge pipe (400) extending outward, each of the discharge pipes (400) is provided with a piston port (410) in the direction of its own axis, each of the discharge pipes (400) is provided with a cutout (420) in a direction orthogonal to its own axis, and any two of the cutouts (420) have mutually staggered orientations; A water tank cover (200), which is close to the discharge pipe (400) and connected to the pelletizing die (100), and the water tank cover (200) is provided with a water inlet end (210) and a water outlet end (220); A piston mechanism (300) comprises a driving device (310), a movable part (320) and a plurality of piston heads (330), wherein all the piston heads (330) are connected to the movable part (320), the driving device (310) drives the movable part (320) to perform linear reciprocating motion, all the piston heads (330) are respectively arranged in one-to-one correspondence with all the piston ports (410), the piston heads (330) are sealingly connected to the corresponding discharge pipe (400), and the moving path of the piston heads (330) covers the corresponding incision (420).

2. The plastic pelletizer according to claim 1, characterized in that: The size of the cutout (420) on the outer wall of the discharge pipe (400) is greater than the size of the cutout (420) on the inner wall of the discharge pipe (400).

3. The plastic pelletizer according to claim 2, characterized in that: The vertical wall of the incision (420) is an incomplete spherical surface.

4. The plastic pelletizer according to claim 1, characterized in that: The pelletizing die (100) is detachably connected to the water tank cover (200).

5. The plastic pelletizer according to claim 4, characterized in that: It also comprises a slide rail, and the water tank cover (200) and the pelletizing die (100) are both slidably connected to the slide rail.

6. The plastic pelletizer according to claim 1, characterized in that: The pelletizing die (100) comprises a first template (110) and a second template (120) which are connected to each other, the main channel (111) is arranged on the first template (110), the branch channel (121) is arranged on the second template (120), and the second template (120) is connected to the water tank cover (200).

7. The plastic pelletizer according to claim 6, characterized in that: The second template (120) is connected to a guide cone (130) extending to the main channel (111), and the size of the guide cone (130) gradually increases from the first template (110) to the second template (120).

8. The plastic pelletizer according to claim 7, characterized in that: All the flow branches (121) are evenly distributed in the circumferential direction around the axis of the flow guide cone (130).

9. The plastic pelletizer according to claim 1, characterized in that: The driving device (310) is installed on the water tank cover (200), and the driving device (310) comprises a cylinder, a crank slider device, an electric push rod or a gear rack device.

10. The plastic pelletizer according to claim 1, characterized in that: It also includes a circulating water pump, which is connected to the water inlet (210) and the water outlet (220) respectively.

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