Screen exchanger core plate, screen exchanger and plastic production equipment facilitating machine testing and material inspection

Abstract

The utility model discloses a screen changer core plate which comprises a material blocking metal plate and at least two filter screen plates, the material blocking metal plate is sequentially provided with two material passing holes, the filter screen plates are used for being detachably installed at the material passing holes, the material blocking metal plate is further provided with a material detecting channel, and the material detecting channel is communicated with the material passing holes. The inner end of the material detection channel is communicated with a front port of one of the material passing holes, and the outer end of the material detection channel is communicated with the outside of the material blocking metal plate. The utility model further provides the screen exchanger and plastic production equipment facilitating machine testing and material inspection. According to the screen exchanger core plate, the screen exchanger and the plastic production equipment convenient for machine testing and material inspection, whether molten plastic is qualified or not is accurately checked during machine testing, the machine testing time is greatly shortened, and material waste and repeated machine testing are avoided.

Description

Technical Field

[0001] This utility model relates to the technical field of screen changer equipment, and in particular to a screen changer core plate, a screen changer, and a plastic production equipment that facilitates trial operation and material inspection. Background Technology

[0002] During extrusion or injection molding operations, a trial run is generally required to check whether the extruded or injection molded products meet the requirements before proceeding with automated production to avoid large-scale scrap. For example, if an extruder fails inspection, the cause could be one of two things: a problem with the extrusion die or a problem with the plasticizing barrel. However, even experienced workers in the plastic extrusion industry cannot directly determine the root cause of the problem from the extruded product through observation or simple testing. Therefore, it is necessary to stop the machine and wait for it to cool down for about 10 hours before inspecting the extrusion die and plasticizing barrel separately (generally, based on experience, one of them is selected for inspection first, and if it cannot be ruled out, the other is inspected). Often, it is necessary to disassemble the machine for inspection, which can take up another day. Moreover, regardless of whether disassembly is required for inspection, a large amount of cooled plastic remains in the die, which must be disassembled, cleaned, and reassembled, taking up almost another day. Then, the die must be reheated to the plasticizing temperature before another trial run can be conducted. This trial run may be repeated many times, wasting a lot of time and a lot of plastic.

[0003] So, is it possible to extrude some molten plastic from the end of the plasticizer barrel during trial operation for testing? Some might think of drilling a screw hole at the end of the plasticizer barrel, plugging and tightening it with a bolt, loosening the bolt during trial operation to let the molten plastic flow out, and then tightening the bolt to plug the screw hole after the trial operation. This method seems plausible, but it is actually not feasible at all. This is because the inner end face of the bolt cannot be completely flush with the inner surface of the plasticizer barrel. There will be a protrusion or depression between the inner end of the bolt and the inner surface of the plasticizer barrel, which will inevitably produce residual material. This residual material will not be carried away by the new molten plastic all at once, but will be carried away a little bit each time. This will inevitably result in a little residual material always being carried with the extrusion, causing the extruded products (such as films) to be unqualified.

[0004] Since molten plastic detection cannot be achieved through perforation, could a breakthrough be made in the screen changer? However, current screen changer structures only have the function of screen changing. For example, the utility model patent CN216986472U discloses a sealed screen changer, including a screen changer body and a fixed plate set above the screen changer body. The fixed plate is equipped with a hydraulic rod, and a feed pipe is connected to the screen changer body. A sliding plate is slidably installed inside the screen changer body. The output end of the hydraulic rod is connected to the top of the sliding plate. The sliding plate has multiple mounting slots, and a filter screen is detachably installed inside each mounting slot. The screen changer body is equipped with a sealing component to prevent raw material leakage during screen changing. The above-mentioned sealed screen changer uses the hydraulic rod to push the sliding plate to switch the position of the mounting slot, thereby achieving the purpose of replacing the filter screen. However, it is clear that the current design concept of screen changers is fixed on how to achieve screen changing, that is, how to achieve rapid disassembly and replacement of the filter screen. There is no technological inspiration to squeeze some molten plastic out of the screen changer for detection. Utility Model Content

[0005] The problem to be solved by this utility model is to provide a screen changer core plate, a screen changer, and a plastic production equipment that facilitates trial operation and material inspection, so as to more accurately check whether the molten plastic is qualified during trial operation, greatly shorten the trial operation time, and avoid material waste and repeated trials.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0007] A screen changer core plate includes a baffle metal plate and at least two filter screen plates. The baffle metal plate has two material passage holes in sequence, and the filter screen plates are detachably installed at the material passage holes. The baffle metal plate is characterized in that: the baffle metal plate is also provided with a material inspection channel, the inner end of the material inspection channel is connected to the front port of one of the material passage holes, and the outer end of the material inspection channel is connected to the outside of the baffle metal plate.

[0008] Typically, the outer end of the aforementioned material inspection channel faces horizontal or below horizontal.

[0009] During trial operation, the screen changer core plate switches to the inspection channel position and blocks the material passage hole where the inspection channel is located. The molten plastic in the plasticizer barrel is blocked and cannot be conveyed forward through the material passage hole. Instead, it flows out through the inspection channel, allowing direct inspection of the molten plastic without the need for it to be extruded from the front extrusion equipment for inspection. After the trial operation is completed and continuous batch production begins, the molten plastic needs to be filtered. Filter plates are installed in at least two material passage holes of the screen changer core plate and switched to the filter plate position to filter the molten plastic. It is also possible to switch between two filter plates to achieve normal screen changing without stopping the machine.

[0010] In a preferred embodiment, the retaining metal plate is rectangular, and the two material passage holes are arranged sequentially along the length of the retaining metal plate; alternatively, the retaining metal plate is semi-circular or arc-shaped, with a shaft hole in the middle of its upper side, and the two material passage holes are located on either side of the shaft hole. The shaft hole of the retaining metal plate is used to insert a rotating rod (generally using bolts for locking the front and rear flanges as the rotating rod), allowing the retaining metal plate to swing back and forth around the rotating rod. The screen changer core plate can switch the position of the two material passage holes in a linear manner, corresponding to a rectangle; or it can switch in a swing manner, corresponding to a semi-circular or arc-shaped shape.

[0011] As a preferred embodiment of this utility model, two mounting grooves are provided on the baffle metal plate, the shape of which matches the filter screen plate, and each of the material passage holes is provided in the corresponding mounting groove. The material inspection channel is connected to the corresponding mounting groove. When the material passage hole in the mounting groove is blocked, the material inspection channel is used to discharge molten plastic.

[0012] As a further preferred embodiment of this utility model, a material inspection plate is also included, the shape of which matches the mounting groove. When material inspection is required for trial operation, the material inspection plate can be detachably installed in one of the mounting grooves, and the material passage hole is blocked by the material inspection plate. The material inspection plate is used to replace one of the filter screen plates during trial operation. Thus, when switching to the position of the material inspection plate during trial operation, the material inspection plate blocks the material passage hole, and the molten plastic flows out from the material inspection channel.

[0013] As a further preferred embodiment of this utility model, the inspection plate has an arc-shaped recess in the middle. The arc-shaped recess in the middle of the inspection plate can smooth out the impact of the molten plastic on the inspection plate, thereby converging it towards the inlet of the inspection channel.

[0014] As a further preferred embodiment of this utility model, the inspection plate is provided with a flow guiding channel, the inner end of the flow guiding channel is connected to the concave part of the arc surface, and the outer end of the flow guiding channel is connected to the inner end of the inspection channel.

[0015] As a further preferred embodiment of this utility model, the flow channel is a through hole, a strip groove, or a notch.

[0016] As a further preferred embodiment of this utility model, the material inspection channel is a through hole or a strip groove. When the material inspection channel is a strip groove, the groove opening is sealed by the mating surface of the flange used to install the screen changer core plate. The cross-section of the through hole is circular, elliptical, or square; the cross-section of the strip groove is semi-circular, semi-elliptical, or square.

[0017] As a further preferred embodiment of this utility model, the mounting groove is circular, elliptical, or square.

[0018] As a preferred embodiment of this utility model, the baffle metal plate is provided with a strip-shaped mounting groove, at least one end of which extends to the side of the baffle metal plate, and each of the material passage holes is opened in the strip-shaped mounting groove; the screen changer core plate also includes a material inspection plate, and the material inspection channel is opened on the material inspection plate. Both the material inspection plate and the filter screen plate are square and match the strip-shaped mounting groove; when a test run is to be performed, the material inspection plate can be detachably installed in the strip-shaped mounting groove, the corresponding material passage hole is blocked by the material inspection plate, and the material inspection channel extends from the strip-shaped mounting groove to the outside of the baffle metal plate.

[0019] As a further preferred embodiment of this utility model, the material blocking metal plate is provided with a locking mechanism for locking the filter screen plate and the inspection plate.

[0020] As a further preferred embodiment of this utility model, the number of locking mechanisms is at least one. The locking mechanism is located at the end of the strip-shaped mounting groove and includes a pressure plate and screws. Screw holes are provided on the side walls of both the pressure plate and the baffle metal plate (screw holes can only be provided on the side walls of the baffle metal plate; through holes should be provided on the pressure plate and the material inspection plate). The pressure plate is locked to the side wall of the baffle metal plate by screws and screw holes, pressing down on the filter screen plate or the material inspection plate. Alternatively, the locking mechanism can consist of only screws. Screw holes are provided on the material inspection plate and the baffle metal plate at the locations where the material inspection plate is installed (screw holes can only be provided on the side walls of the baffle metal plate; through holes should be provided on the material inspection plate). The material inspection plate is directly locked to the baffle metal plate by screws.

[0021] When testing and material inspection are required, a material inspection plate is installed in one of the material passage holes of the screen changer core plate (material blocking metal plate) and switched to the material inspection plate position. The molten plastic in the plasticizer barrel is blocked by the material inspection plate and cannot be conveyed forward through the material passage hole. Instead, it flows out through the material inspection channel, allowing direct inspection of the molten plastic without the need for it to be extruded from the front extrusion equipment for inspection. After the test run is completed and continuous batch production begins, the molten plastic needs to be filtered. The material inspection plate can be removed, and filter screens can be installed in at least two material passage holes of the screen changer core plate and switched to the filter screen position to filter the molten plastic. It is also possible to switch between two filter screens to achieve normal screen changing without stopping the machine.

[0022] When continuous batch production begins after the trial run is completed, the inner end of the inspection channel is blocked by the filter screen after the material passage is fitted with a filter screen.

[0023] The aforementioned retaining metal plates are generally made of stainless steel, but can also be made of copper, alloys, or special steels.

[0024] The aforementioned filter screen generally includes a metal frame and a metal filter screen set in the metal frame, and is generally made of stainless steel.

[0025] The aforementioned inspection plates are generally made of metals such as stainless steel.

[0026] A screen changer includes a front flange seat and a rear flange seat. A front flow channel is provided in the front flange seat, and a rear flow channel is provided in the rear flange seat. The front and rear flange seats are locked together by a connector, and a gap exists between them. The device is characterized by further including a screen changer core plate. The screen changer core plate is located within the gap and in close contact with the front and rear flange seats. A sealing ring assembly is provided between the screen changer core plate and the front flange seat. When the screen changer core plate is switched to a filter screen plate, the filter screen plate connects the front and rear flow channels. When the screen changer core plate is switched to a material inspection plate, the material inspection plate blocks the front and rear flow channels, and the material inspection channel connects with the front flow channel.

[0027] In a preferred embodiment, the sealing ring assembly includes a steel sealing ring and a plastic sealing ring. The rear side of the front flange seat has an annular step, within which the plastic and steel sealing rings are positioned. The plastic sealing ring is located in front of the steel sealing ring. The rear side of the steel sealing ring is a flat annular plane, with an annular concave surface on its front side and an annular convex surface on its rear side, the convex surface resting within the annular concave surface. The plastic sealing ring expands under heat, pressing against the steel sealing ring, causing it to adhere tightly to the retaining metal plate of the screen changer core plate, while maintaining smoothness during switching and a certain degree of elasticity.

[0028] In a further preferred embodiment, the plastic sealing ring is made of polytetrafluoroethylene (PTFE).

[0029] The aforementioned switching of the screen changer core plate can be a linear switching, such as switching up and down or left and right, or a rotational switching, for example, by hingedly connecting the middle of the screen changer core plate to the front flange seat / rear flange seat, and switching the filter screen plate and the material inspection channel by rotating the screen changer core plate.

[0030] During trial operation, first switch the screen changer core plate to the inspection plate position, connecting the front flow channel and the inspection channel, while blocking the front and rear flow channels. The molten plastic in the plasticizing barrel will not flow forward into the molding device (such as the extrusion die). Instead, the molten plastic flows through the front flow channel to the inspection channel and is directly discharged from the equipment. Operators use other containers to collect the discharged molten plastic. Operators can observe the state of the discharged molten plastic (such as color, uniformity, and flowability) to determine if the molten plastic is qualified. If the molten plastic is undercooked or overcooked, a malfunction in the plasticizing barrel can be identified and rectified without repeatedly waiting for cooling and cleaning the molding device (such as the extrusion die) to troubleshoot the problem, saving a significant amount of plastic, time, and manpower. If the molten plastic is qualified, the normal extrusion stage begins.

[0031] During normal extrusion, the screen changer core plate is first switched to the filter screen plate. The removed inspection plate is also typically replaced with a filter screen plate, connecting the front flow channel to the rear flow channel via the filter screen plate. Molten plastic flows from the front flow channel through the filter screen plate into the rear flow channel, where it is filtered to intercept foreign particles and impurities. The filtered, clean molten plastic then flows forward from the rear flow channel into the molding device (such as the extrusion die). In the initial stage of normal extrusion, the operator can observe the state of the molten plastic discharged from the extrusion die (or other molding device) (such as color, uniformity, and flowability) to determine if the molten plastic is qualified and, consequently, whether there is a malfunction in the extrusion die (or other molding equipment).

[0032] In a preferred embodiment of this invention, the cross-sectional area of ​​the material inspection channel is 0.3-0.6 times that of the front flow channel. Setting the cross-sectional area of ​​the material inspection channel to 0.3-0.6 times that of the front flow channel ensures that the material flow capacity of the material inspection channel is comparable to that of the filter screen, avoiding excessive pressure or severe pressure leakage. Generally, during normal operation, the filter screen obstructs the molten plastic (the flow area of ​​the filter screen is approximately 0.3-0.6 times that of the front flow channel), slowing down the flow rate of the molten plastic and correspondingly reducing the flow rate of the front flow channel. Therefore, when the cross-sectional area of ​​the material inspection channel is set to 0.3-0.6 times that of the front flow channel, the flow rates of the two are comparable.

[0033] As a further preferred embodiment of this utility model, the cross-sectional area of ​​the material inspection channel is 30 / 65 times the cross-sectional area of ​​the front flow channel.

[0034] As a preferred embodiment of this invention, the screen changer further includes a switching mechanism capable of driving the retaining metal plate to switch positions. Without this switching mechanism, switching can be performed manually, but this is labor-intensive.

[0035] As a further preferred embodiment of this utility model, the retaining metal plate is semi-circular or arc-shaped, with a shaft hole in the middle of its upper side. The connecting member includes a first bolt and at least two second bolts. The first bolt passes through the shaft hole in the retaining metal plate, and each of the second bolts is located outside the movement trajectory of the lower edge of the retaining metal plate. The switching mechanism is fixedly installed on one side of the front or rear flange, and the power output end of the switching mechanism is hinged to the retaining metal plate. By pushing the retaining metal plate to swing around the first bolt through the switching mechanism, the switching between the filter screen plate and the inspection plate is realized.

[0036] As a further preferred embodiment of this utility model, a protrusion is also fixedly provided on the baffle metal plate, and the power output end of the switching mechanism is hinged to the protrusion.

[0037] As a further preferred embodiment of this utility model, the retaining metal plate is rectangular, the connecting member is a fixed seat, and both the front flange seat and the rear flange seat are locked to one side of the fixed seat. Specifically, the front flange seat and the rear flange seat are locked to the lower, left, or right side of the fixed seat. Both the front flange seat and the rear flange seat can be locked to one side of the fixed seat by bolts.

[0038] As a further preferred embodiment of this utility model, the fixed base is provided with a sliding channel communicating with the gap, and the baffle metal plate can slide in the gap and the sliding channel to switch positions; the power output end of the switching mechanism is connected to one end of the baffle metal plate.

[0039] As a further preferred embodiment of this utility model, the switching mechanism includes a cylinder and an air pump capable of providing power to the cylinder; the cylinder is mounted on the fixed base, and the piston rod of the cylinder extends into the sliding channel and is connected to one end of the baffle metal plate. During operation, the cylinder is first connected to the air pump, the air pump is started, and the piston rod of the cylinder drives the baffle metal plate to move and switch within the sliding channel and gap.

[0040] As a further preferred embodiment of this utility model, the switching mechanism includes a hydraulic cylinder and an oil pump capable of providing power to the hydraulic cylinder; the hydraulic cylinder is mounted on the fixed base, and the piston rod of the hydraulic cylinder extends into the sliding channel and is connected to one end of the retaining metal plate. During operation, the hydraulic cylinder is first connected to the oil pump, the hydraulic oil pump is started, and the piston rod of the hydraulic cylinder drives the retaining metal plate to move and switch within the sliding channel and gap.

[0041] In a further preferred embodiment, the oil pump is a hydraulic oil pump.

[0042] In a further preferred embodiment, the hydraulic pump is a manual hydraulic pump. This manual hydraulic pump is compact, easy to transport, and convenient to equip with screen changers on various plasticizing machine drums.

[0043] A plastic production equipment that facilitates trial operation and material inspection includes a plasticizing cylinder and a molding device, wherein the screen changer is provided between the plasticizing cylinder and the molding device.

[0044] As a preferred embodiment of this utility model, the plastic production equipment is an extruder, injection molding machine, plastic granulator, or non-woven fabrication machine.

[0045] As a further preferred embodiment of this utility model, the extruder is a blown film machine, a casting machine, a laminating machine, a coating machine, a pipe extruder, a bottle blowing machine, or a sheet calender.

[0046] Compared with the prior art, this utility model has the following advantages:

[0047] (1) Based on the existing screen changer, this utility model only adds a material inspection channel without adding complex driving components. It can switch between test and filter by switching the position of the baffle metal plate between the filter screen plate and the material inspection plate. The operation is simple, and it can accurately check the melting state of the molten plastic, greatly shorten the test time, and avoid waste of molten plastic and repeated test.

[0048] (2) When testing this utility model, as long as you switch to the inspection channel (inspection plate) first, the front flow channel and the rear flow channel are blocked. The molten plastic in the plasticizing barrel will not flow into the front molding device, but will flow out from the inspection channel. At this time, you can directly observe and inspect the molten plastic to determine whether the molten plastic is qualified. If the molten plastic is not cooked or overcooked, the fault must be on the plasticizing barrel. There is no need to wait for cooling and clean the molding device repeatedly to eliminate the fault, saving a lot of plastic, time and manpower. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the structure of the baffle metal plate in specific embodiment 1 of this utility model;

[0050] Figure 2 This is a schematic diagram of the structure of the filter screen in specific embodiment 1 of this utility model;

[0051] Figure 3 This is a schematic diagram of the material inspection plate in specific embodiment 1 of this utility model;

[0052] Figure 4 This is a schematic diagram of the structure of the material-blocking metal plate in the material inspection station in specific embodiment 1 of this utility model;

[0053] Figure 5 This is a schematic diagram of the structure of the baffle metal plate in the filtration station in specific embodiment 1 of this utility model;

[0054] Figure 6 This is a schematic diagram of the sealing ring assembly in the front flange seat of a specific embodiment of this utility model;

[0055] Figure 7 This is a schematic diagram of the structure of the plastic production equipment in specific embodiment 1 of this utility model;

[0056] Figure 8 This is a three-dimensional structural diagram of the screen switcher in specific embodiment 2 of this utility model;

[0057] Figure 9 This is a schematic diagram of the screen switcher in specific embodiment 2 of this utility model;

[0058] Figure 10 This is a schematic diagram of the core plate of the screen changer in specific embodiment 2 of this utility model;

[0059] Figure 11 This is a structural schematic diagram of specific embodiment 4 of the present utility model. Detailed Implementation

[0060] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0061] Example 1, as Figure 1-7 As shown, the screen changer core plate in this embodiment includes a baffle metal plate 1 and at least two filter screen plates 2. The baffle metal plate 1 is provided with two material passage holes 11 in sequence. The filter screen plates 2 are detachably installed at the material passage holes 11. The baffle metal plate 1 is also provided with a material inspection channel 12. The inner end of the material inspection channel 12 is connected to the front port of one of the material passage holes 11, and the outer end of the material inspection channel 12 is connected to the outside of the baffle metal plate 1.

[0062] Typically, the outer end of the aforementioned material inspection channel 12 faces horizontal or below.

[0063] During trial operation, the screen changer core plate switches to the inspection channel 12 position and blocks the material passage 11 where the inspection channel 12 is located. The molten plastic in the plasticizer barrel is blocked and cannot be conveyed forward through the material passage 11, but flows out through the inspection channel 12. The molten plastic can be directly inspected without having to be extruded from the front extrusion equipment for inspection. After the trial operation is completed and continuous batch production is carried out, the molten plastic needs to be filtered. Filter plates 2 are installed on at least two material passages 11 of the screen changer core plate and switched to the position of filter plates 2 to filter the molten plastic. It is also possible to switch between the two filter plates 2 to achieve normal screen changing without stopping the machine.

[0064] The material-blocking metal plate 1 is rectangular, and the two material passage holes 11 are arranged sequentially along the length of the material-blocking metal plate 1. The screen changer core plate can switch the positions of the two material passage holes 11 in a linear manner, corresponding to the rectangle.

[0065] Two mounting grooves 13 are provided on the baffle metal plate 1. The shape of the mounting grooves 13 matches the filter screen plate 2. Each of the material passage holes 11 is provided in the corresponding mounting groove 13. The material inspection channel 12 communicates with the corresponding mounting groove 13. When the material passage hole 11 in the mounting groove 13 is blocked, the material inspection channel 12 is used to discharge molten plastic.

[0066] This embodiment also includes a material inspection plate 3, the shape of which matches the mounting groove 13. When material inspection is required for trial operation, the material inspection plate 3 can be detachably installed in one of the mounting grooves 13, and the material passage hole 11 is blocked by the material inspection plate 3. The material inspection plate 3 is used to replace one of the filter screen plates 2 during trial operation. Thus, during trial operation, the position of the material inspection plate 3 is switched, and the material inspection plate 3 blocks the material passage hole 11, allowing the molten plastic to flow out through the material inspection channel 12. The mounting groove 13 is circular.

[0067] The inspection plate 3 has an arc-shaped recess 31 in the middle. The arc-shaped recess 31 in the middle of the inspection plate 3 can smooth the impact of molten plastic on the inspection plate 3, and then converge it towards the inlet of the inspection channel 12.

[0068] The inspection plate 3 has a flow channel 32. The inner end of the flow channel 32 communicates with the arc-shaped concave portion 31, and the outer end of the flow channel 32 is connected to the inner end of the inspection channel 12.

[0069] The aforementioned flow channel 32 can be a through hole, a strip groove, or a notch.

[0070] The aforementioned inspection channel 12 is either a through hole or a strip groove. When the inspection channel 12 is a strip groove, the groove opening is sealed by the mating surface of the flange used to install the screen changer core plate; the cross-section of the strip groove is semi-circular, semi-elliptical, or square. When the inspection channel 12 is a through hole, the cross-section of the through hole is circular, elliptical, or square.

[0071] The aforementioned mounting groove 13 is circular, elliptical, or square. Correspondingly, the filter plate 2 and the inspection plate 3 are also circular. Circular shapes are easy to process with high precision, which greatly reduces processing costs.

[0072] When testing and material inspection are required, the inspection plate 3 is installed in one of the mounting slots 13 of the screen changer core plate (material blocking metal plate 1), and the screen changer is switched to the position of the inspection plate 3. The molten plastic in the plasticizer barrel is blocked by the inspection plate 3 and cannot be conveyed forward through the material passage 11. Instead, it flows out through the inspection channel 12, allowing direct inspection of the molten plastic without the need for the molten plastic to be extruded from the front extrusion equipment for inspection. When continuous batch production is carried out after the test run, the molten plastic needs to be filtered. The inspection plate 3 can be removed, and filter screen plates 2 can be installed in at least two material passages 11 of the screen changer core plate. The screen changer is switched to the position of the filter screen plates 2 to filter the molten plastic. The screen changer can also switch between the two filter screen plates 2 to achieve normal screen change without stopping the machine.

[0073] When continuous batch production begins after the trial run is completed, the inner end of the inspection channel 12 is blocked by the filter screen plate 2 after the filter screen plate 2 is installed on the material passage 11.

[0074] The aforementioned retaining metal plate 1 is generally made of stainless steel, but can also be made of metals such as copper, alloys, or special steel.

[0075] The aforementioned filter plate 2 generally includes a metal frame 21 and a metal filter 22 disposed in the metal frame 21, which is generally made of stainless steel.

[0076] The aforementioned inspection plate 3 is generally made of metals such as stainless steel.

[0077] A screen changer A includes a front flange seat 4, a rear flange seat 5, and a screen changer core plate. The front flange seat 4 has a front flow channel 41, and the rear flange seat 5 has a rear flow channel 51. The front flange seat 4 and the rear flange seat 5 are locked together by a connector 6. There is a gap 7 between the front flange seat 4 and the rear flange seat 5. The screen changer core plate is located in the gap 7 and is in close contact with the front flange seat 4 and the rear flange seat 5. A sealing ring assembly 8 is provided between the screen changer core plate and the front flange seat 4. When the screen changer core plate is switched to the filter screen plate 2, the filter screen plate 2 connects the front flow channel 41 and the rear flow channel 51. When the screen changer core plate is switched to the inspection plate 3, the inspection plate 3 blocks the front flow channel 41 and the rear flow channel 51, and the inspection channel 12 connects to the front flow channel 41.

[0078] The sealing ring assembly 8 includes a steel sealing ring 81 and a plastic sealing ring 82. The rear side of the front flange seat 4 has an annular step 41. The plastic sealing ring 82 and the steel sealing ring 81 are disposed within the annular step 41, with the plastic sealing ring 82 positioned in front of the steel sealing ring 81. The rear side of the steel sealing ring 81 is a flat annular plane 811, and the front side of the steel sealing ring 81 has an annular concave surface 812. The rear side of the plastic sealing ring 82 has an annular convex surface 821, which is located within the annular concave surface 812. When heated, the plastic sealing ring 82 expands and presses against the steel sealing ring 81, causing the steel sealing ring 81 to adhere tightly to the retaining metal plate 1 of the screen changer core plate, while maintaining smoothness during switching and possessing a certain degree of elasticity.

[0079] The plastic sealing ring 82 is made of polytetrafluoroethylene (PTFE).

[0080] The aforementioned switching of the screen changer core plate can be a linear switching, such as switching up and down or left and right, or a rotational switching. For example, the middle part of the screen changer core plate is hinged to the front flange seat 4 / rear flange seat 5, and the screen changer core plate is rotated to achieve the switching of the filter screen plate 2 and the material inspection channel 12.

[0081] During trial operation, the screen changer core plate is first switched to the inspection plate 3, connecting the front flow channel 41 with the inspection channel 12, while blocking the front flow channel 41 from the rear flow channel 51. The molten plastic in the plasticizing barrel does not flow forward into the molding device (such as the extrusion die). Instead, the molten plastic flows through the front flow channel 41 to the inspection channel 12 and is directly discharged from the equipment. The operator collects the discharged molten plastic in another container. The operator can observe the state of the discharged molten plastic (such as color, uniformity, and flowability) to determine if the molten plastic is qualified. If the molten plastic is undercooked or overcooked, a malfunction in the plasticizing barrel can be identified and rectified without repeatedly waiting for cooling and cleaning the molding device (such as the extrusion die) to troubleshoot the problem, saving a significant amount of plastic, time, and manpower. If the molten plastic is qualified, the normal extrusion stage begins.

[0082] During normal extrusion, the screen changer core plate is first switched to filter screen 2. The removed inspection plate 3 is also typically replaced with filter screen 2, connecting the front flow channel 41 to the rear flow channel 51 via filter screen 2. Molten plastic flows from the front flow channel 41 through filter screen 2 into the rear flow channel 51, where it is filtered to intercept foreign particles and impurities. The filtered, clean molten plastic then flows forward from the rear flow channel 51 into the molding device (such as the extrusion die). In the initial stage of normal extrusion, the operator can observe the state of the molten plastic discharged from the extrusion die (or other molding device) (such as color, uniformity, and flowability) to determine if the molten plastic is qualified and, consequently, whether there is a malfunction in the extrusion die (or other molding equipment).

[0083] The cross-sectional area of ​​the material inspection channel 12 is 0.3-0.6 times that of the front flow channel 41. Setting the cross-sectional area of ​​the material inspection channel 12 to 0.3-0.6 times that of the front flow channel 41 ensures that the material flow capacity of the material inspection channel 12 is comparable to that of the filter screen 2, avoiding excessive pressure or severe pressure leakage. Generally, during normal operation, the filter screen 2 obstructs the molten plastic (the flow area of ​​the filter screen 2 is approximately 0.3-0.6 times that of the front flow channel 41), slowing down the flow rate of the molten plastic and correspondingly reducing the flow rate of the front flow channel 41. Therefore, when the cross-sectional area of ​​the material inspection channel 12 is set to 0.3-0.6 times that of the front flow channel 41, the flow rates of the two are comparable.

[0084] The cross-sectional area of ​​the material inspection channel 12 is 30 / 65 times the cross-sectional area of ​​the front flow channel 41.

[0085] The screen changer also includes a switching mechanism 9 that can drive the retaining metal plate 1 to switch positions. Without the switching mechanism 9, switching can be performed manually, but this is laborious.

[0086] The retaining metal plate 1 is rectangular, and the connecting piece 6 is a fixing seat 61. The front flange seat 4 and the rear flange seat 5 are both locked to one side of the fixing seat 61. Specifically, the front flange seat 4 and the rear flange seat 5 are locked to the lower, left, or right side of the fixing seat 61. Both the front flange seat 4 and the rear flange seat 5 can be locked to one side of the fixing seat 61 with bolts.

[0087] The fixed base 61 has a sliding channel 611 that communicates with the gap 7. The baffle metal plate 1 can slide in the gap 7 and the sliding channel 611 to switch positions. The power output end of the switching mechanism 9 is connected to one end of the baffle metal plate 1.

[0088] The switching mechanism 9 includes a hydraulic cylinder 91 and an oil pump 92 that provides power to the hydraulic cylinder 91. The hydraulic cylinder 91 is mounted on the fixed base 61, and the piston rod of the hydraulic cylinder 91 extends into the sliding channel 611 and is connected to one end of the retaining metal plate 1. During operation, the hydraulic cylinder 91 is first connected to the oil pump 92, and the hydraulic oil pump 92 is started. The piston rod of the hydraulic cylinder 91 drives the retaining metal plate 1 to move and switch between the sliding channel 611 and the gap 7.

[0089] Oil pump 92 is a hydraulic oil pump 92. The hydraulic oil pump 92 is a manual hydraulic oil pump 92. The aforementioned manual hydraulic oil pump 92 is compact, easy to transport, and convenient to equip with screen changers on various plasticizing machine drums.

[0090] A plastic production equipment for easy trial operation and material inspection includes a plasticizing barrel 101 and a molding device 102, with the screen changer A provided between the plasticizing barrel 101 and the molding device 102. A feeding mechanism 1011 is provided on the plasticizing barrel 101. The plastic production equipment can be an extruder, injection molding machine, plastic granulator, or nonwoven fabric filament machine.

[0091] Extruders include blown film extruders, casting machines, laminating machines, coating machines, pipe extruders, bottle blowing machines, or sheet calenders.

[0092] Example 2, as Figure 8-10 As shown, the difference between this embodiment and Embodiment 1 lies in the following features:

[0093] The retaining metal plate 1 is arc-shaped or semi-circular. A shaft hole 14 is located in the center of the upper side of the retaining metal plate 1, and two material passage holes 11 are located on either side of the shaft hole 14. The shaft hole 14 of the retaining metal plate 1 is used to insert a rotating rod (generally using bolts for locking the front and rear flanges as the rotating rod). The retaining metal plate 1 can swing back and forth around the rotating rod. The screen changer core plate can switch the position of the two material passage holes 11 using a swing-type switching mechanism.

[0094] The connecting member 6 includes a first bolt 62 and at least two second bolts 63. The first bolt 62 passes through the shaft hole 14 on the retaining metal plate 1, and each of the second bolts 63 is outside the movement trajectory of the lower edge of the retaining metal plate 1. The switching mechanism 9 (hydraulic cylinder 91) is fixedly installed on one side of the front flange seat or the rear flange seat, and the power output end of the switching mechanism 9 is hinged to the retaining metal plate 1. By pushing the retaining metal plate 1 to swing around the first bolt 62 through the switching mechanism 9, the switching between the filter screen plate 2 and the inspection plate 3 is realized.

[0095] A protrusion 15 is also fixedly provided on the baffle metal plate 1, and the power output end of the switching mechanism 9 is hinged to the protrusion 15.

[0096] Example 3, the difference between this example and Example 1 is as follows:

[0097] The switching mechanism 9 includes a cylinder and an air pump that provides power to the cylinder. The cylinder is mounted on the fixed base 61, and the piston rod of the cylinder extends into the sliding channel 611 and is connected to one end of the baffle metal plate 1. During operation, the cylinder is first connected to the air pump, the air pump is started, and the piston rod of the cylinder drives the baffle metal plate 1 to move and switch between the sliding channel 611 and the gap 7.

[0098] Example 4, as Figure 11 As shown, the difference between this embodiment and Embodiment 1 lies in the following features:

[0099] The baffle metal plate 1 has a strip-shaped mounting groove 16, which is formed by two mounting grooves 13 connected together. At least one end of the strip-shaped mounting groove 16 extends to the side of the baffle metal plate 1. Each of the material passage holes 11 is opened in the strip-shaped mounting groove 16. The screen changer core plate also includes a material inspection plate 3. The material inspection channel 12 is opened on the material inspection plate 3. Both the material inspection plate 3 and the filter screen plate 2 are square and match the strip-shaped mounting groove 16. When the machine is to be tested for material inspection, the material inspection plate 3 can be detachably installed in the strip-shaped mounting groove 16. The corresponding material passage hole 11 is blocked by the material inspection plate 3, and the material inspection channel 12 extends from the strip-shaped mounting groove 16 to the outside of the baffle metal plate 1.

[0100] The material blocking metal plate 1 is also provided with a locking mechanism 17 for locking the filter screen plate 2 and the inspection plate 3.

[0101] At least one locking mechanism 17 is provided at the end of the strip mounting groove 16. The locking mechanism 17 includes a pressure plate 171 and a screw 172. Both the pressure plate 171 and the sidewall of the retaining metal plate 1 have screw holes (screw holes can only be provided on the sidewall of the retaining metal plate 1; through holes should be provided on the pressure plate 171 and the inspection plate 3). The pressure plate 171 is locked to the sidewall of the retaining metal plate 1 by the screw 172 and the screw holes, pressing down on the filter screen plate 2 or the inspection plate 3. Alternatively, the locking mechanism can consist of only a screw. The inspection plate 3 and the retaining metal plate 1 have screw holes at the mounting points (screw holes can only be provided on the sidewall of the retaining metal plate 1; through holes should be provided on the inspection plate 3). The inspection plate 3 is directly locked to the retaining metal plate 1 by the screw.

[0102] Furthermore, it should be noted that the names of the various parts of the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, they should all fall within the protection scope of this utility model.

Claims

1. A screen changer core plate, comprising a baffle metal plate and at least two filter screen plates, wherein the baffle metal plate is provided with two material passage holes in sequence, and the filter screen plates are detachably installed at the material passage holes, characterized in that: The baffle metal plate is also provided with a material inspection channel. The inner end of the material inspection channel is connected to the front port of one of the material passage holes, and the outer end of the material inspection channel is connected to the outside of the baffle metal plate.

2. The screen changer core board as described in claim 1, characterized in that: The baffle metal plate is rectangular, and the two material passage holes are arranged sequentially along the length of the baffle metal plate; or, the baffle metal plate is semi-circular or arc-shaped, and a shaft hole is provided in the middle of the upper side of the baffle metal plate, with the two material passage holes located on both sides of the shaft hole.

3. The screen changer core board as described in claim 2, characterized in that: The baffle metal plate has two mounting slots, the shape of which matches the filter screen plate. Each of the material passage holes is located in the corresponding mounting slot, and the material inspection channel is connected to the corresponding mounting slot. When the material passage hole in the mounting slot is blocked, the material inspection channel is used to discharge molten plastic.

4. The screen changer core board as described in claim 3, characterized in that: It also includes a material inspection plate, the shape of which matches the mounting slot; when a test run is to be performed, the material inspection plate can be detachably installed in one of the mounting slots, and the material passage hole is blocked by the material inspection plate.

5. The screen changer core board as described in claim 4, characterized in that: The inspection plate has an arc-shaped recess in the middle.

6. The screen changer core board as described in claim 5, characterized in that: The inspection plate has a flow guiding channel, the inner end of which communicates with the concave part of the arc surface, and the outer end of which is connected to the inner end of the inspection channel.

7. The screen changer core board as described in claim 6, characterized in that: The flow channel is a through hole, a strip groove, or a notch.

8. The screen changer core board as described in claim 3, characterized in that: The material inspection channel is a through hole or a strip groove.

9. The screen changer core board as described in claim 3, characterized in that: The mounting slot can be circular, elliptical, or square.

10. The screen changer core board as described in claim 2, characterized in that: The baffle metal plate has a strip-shaped mounting groove, at least one end of which extends to the side of the baffle metal plate. Each of the material passage holes is opened in the strip-shaped mounting groove. The screen changer core plate also includes a material inspection plate, and the material inspection channel is opened on the material inspection plate. Both the material inspection plate and the filter screen plate are square and match the strip-shaped mounting groove. When a test run is to be performed, the material inspection plate can be detachably installed in the strip-shaped mounting groove, the corresponding material passage hole is blocked by the material inspection plate, and the material inspection channel extends from the strip-shaped mounting groove to the outside of the baffle metal plate.

11. The screen changer core board as described in claim 10, characterized in that: The material-blocking metal plate is provided with a locking mechanism for locking the filter screen plate and the inspection plate.

12. The screen changer core board as described in claim 11, characterized in that: The number of locking mechanisms is at least one. The locking mechanism is located at the end of the strip mounting groove. The locking mechanism includes a pressure plate and screws. The side walls of the pressure plate and the baffle metal plate are provided with screw holes. The pressure plate is locked to the side wall of the baffle metal plate by screws and screw holes, and presses down the filter screen plate or the inspection plate.

13. A screen changer, comprising a front flange seat and a rear flange seat, wherein a front flow channel is provided in the front flange seat and a rear flow channel is provided in the rear flange seat, the front flange seat and the rear flange seat are locked together by a connecting member, and a gap exists between the front flange seat and the rear flange seat, characterized in that: It also includes the screen changer core plate according to any one of claims 3-12; the screen changer core plate is in the gap and in close contact with the front flange seat and the rear flange seat, and a sealing ring assembly is provided between the screen changer core plate and the front flange seat; when the screen changer core plate is switched to the filter screen plate, the filter screen plate connects the front flow channel and the rear flow channel; when the screen changer core plate is switched to the inspection plate, the inspection plate blocks the front flow channel and the rear flow channel, and the inspection channel is connected to the front flow channel.

14. The screen changer as described in claim 13, characterized in that: The sealing ring assembly includes a steel sealing ring and a plastic sealing ring. The rear side of the front flange seat is provided with an annular step. The plastic sealing ring and the steel sealing ring are disposed in the annular step. The plastic sealing ring is located in front of the steel sealing ring. The rear side of the steel sealing ring is a flat annular plane. The front side of the steel sealing ring is provided with an annular concave surface. The rear side of the plastic sealing ring is provided with an annular convex surface. The annular convex surface is located in the annular concave surface.

15. The screen changer as described in claim 14, characterized in that: The plastic sealing ring is made of polytetrafluoroethylene.

16. The screen changer as described in claim 13, characterized in that: The cross-sectional area of ​​the material inspection channel is 0.3-0.6 times that of the cross-sectional area of ​​the front flow channel.

17. The screen changer as described in claim 16, characterized in that: The cross-sectional area of ​​the material inspection channel is 30 / 65 times the cross-sectional area of ​​the front flow channel.

18. The screen changer as described in claim 13, characterized in that: It also includes a switching mechanism that can drive the stop metal plate to switch positions.

19. The screen changer as described in claim 18, characterized in that: The retaining metal plate is semi-circular or arc-shaped, and a shaft hole is provided in the middle of the upper side of the retaining metal plate. The connecting member includes a first bolt and at least two second bolts. The first bolt passes through the shaft hole in the retaining metal plate, and each second bolt is outside the movement trajectory of the lower edge of the retaining metal plate. The switching mechanism is fixedly installed on one side of the front flange or the rear flange, and the power output end of the switching mechanism is hinged to the retaining metal plate.

20. The screen changer as described in claim 19, characterized in that: The baffle metal plate is also fixedly provided with a protrusion, and the power output end of the switching mechanism is hinged to the protrusion.

21. The screen changer as described in claim 18, characterized in that: The baffle metal plate is rectangular, the connector is a fixed seat, and the front flange seat and the rear flange seat are both locked to one side of the fixed seat.

22. The screen changer as described in claim 21, characterized in that: The fixed base has a sliding channel communicating with the gap, and the baffle metal plate can slide in the gap and the sliding channel to switch positions; the power output end of the switching mechanism is connected to one end of the baffle metal plate.

23. The screen changer as described in claim 22, characterized in that: The switching mechanism includes a cylinder and an air pump that can provide power to the cylinder; the cylinder is mounted on the fixed base, and the piston rod of the cylinder extends into the sliding channel and is connected to one end of the baffle metal plate.

24. The screen changer as described in claim 22, characterized in that: The switching mechanism includes a hydraulic cylinder and an oil pump that can provide power to the hydraulic cylinder; the hydraulic cylinder is mounted on the fixed base, and the piston rod of the hydraulic cylinder extends into the sliding channel and is connected to one end of the stop metal plate.

25. The screen changer as described in claim 24, characterized in that: The oil pump is a hydraulic oil pump.

26. The screen changer as described in claim 25, characterized in that: The hydraulic pump is a manual hydraulic pump.

27. A plastic production equipment that facilitates trial operation and material inspection, comprising a plasticizing cylinder and a molding device, wherein a screen changer is provided between the plasticizing cylinder and the molding device, characterized in that: The screen switcher is the screen switcher according to any one of claims 13-26.

28. The plastic production equipment as described in claim 27, which facilitates trial production and material inspection, is characterized in that: The plastic production equipment is an extruder, injection molding machine, plastic granulator, or nonwoven fabrication machine.

29. The plastic production equipment as described in claim 28, which facilitates trial production and material inspection, is characterized in that: The extruder is a blown film extruder, a casting machine, a laminating machine, a coating machine, a pipe extruder, a bottle blowing machine, or a sheet calender.

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