Polyethylene particle abnormal screening device and screening method

Abstract

The present invention discloses a polyethylene particle abnormal screening device, which includes: a conveyor belt, on which a plurality of grooves are distributed in a matrix, and a drop port that can be opened and closed is provided at the bottom of the groove; a plurality of feature extractors, which can move relative to the conveyor belt so as to correspond one-to-one with a group of grooves, and each feature extractor includes: a high-speed camera, which collects image information of particles in the corresponding groove; and a plurality of lifting rods, which are distributed in a circle around the high-speed camera, and the lifting rods move up and down to change the posture of the particles in the corresponding groove; and a controller, which is connected to the conveyor belt and the plurality of feature extractors in communication, and the controller opens the drop port according to the image information obtained by the high-speed camera. The present invention also discloses a polyethylene particle abnormal screening method. The present invention can obtain images of particles in different postures through the coordinated design of the grooves and the feature extractors, realize all-round detection of the particles, and greatly improve the recognition and sorting accuracy and efficiency of abnormal particles.

Description

Technical Field

[0001] The invention relates to the technical field of polyethylene material production, and in particular to a polyethylene particle abnormal screening device and a screening method. Background Art

[0002] High-density polyethylene material has the characteristics of acid and alkali resistance, organic solvent resistance, excellent electrical insulation, low-temperature toughness, etc. It has a wide range of uses. It can be used to form various types of containers, industrial accessories, medical products, toys, shells, bottle stoppers and shields by injection molding, various hollow containers, ultra-thin films, etc. by blow molding, and pipes, stretch strips, strapping tapes, monofilaments, wires and cable sheaths, etc. by extrusion molding. In the production process, due to the influence of factors such as the long-term operation of the granulation unit and the coking of metallocene catalysts, the high-density polyethylene granule products will be mixed with unqualified particles with black or other color spots, affecting the overall quality of the product and the economic benefits of the enterprise. The industry mainly adopts two measures to solve the above problems: one is to reduce the carbonization of the resin during the granulation process, and the other is to reduce the concentration of small particle size components in the powder resin into the granulation extruder. Although the above two measures can reduce the unqualified particle rate to a certain extent, the production of inferior particles is always unavoidable.

[0003] Therefore, the sorting process of polyethylene particles is essential. However, in the existing technology, manual quality inspection has low efficiency and high missed inspection rate, which is difficult to meet the urgent needs of enterprises to improve product quality and output; there are few automated quality inspection technologies for resin particles, which cannot meet the sorting requirements in the production process of polyethylene particles.

[0004] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] One of the purposes of the present invention is to provide a polyethylene particle abnormal screening device and screening method, so as to improve the quality inspection efficiency and accuracy of polyethylene particles.

[0006] To achieve the above-mentioned purpose, according to the first aspect of the present invention, there is provided a polyethylene particle abnormal screening device, which comprises: a conveyor belt having a plurality of grooves distributed in a matrix, and a drop port that can be opened and closed is provided at the bottom of the groove; a plurality of feature extractors that can move relative to the conveyor belt so as to correspond one-to-one with a group of grooves, and each feature extractor comprises: a high-speed camera that collects image information of particles in the corresponding groove; and a plurality of lifting rods that are distributed in a circle around the high-speed camera, and the lifting rods move up and down to change the posture of particles in the corresponding groove; and a controller that is communicatively connected to the conveyor belt and the plurality of feature extractors, and the controller opens the drop port according to the image information acquired by the high-speed camera.

[0007] Furthermore, in the above technical solution, a hook is provided at the lower end of the lifting rod, and the hook is made of elastic material.

[0008] Furthermore, in the above technical solution, adjacent lifting rods of the feature extractor move up and down at intervals.

[0009] Furthermore, in the above technical solution, a plurality of lifting rods rotate around the high-speed camera.

[0010] Furthermore, in the above technical solution, the diameter of the circle surrounded by the multiple lifting rods is the same as the maximum size of the particles.

[0011] Furthermore, in the above technical solution, the bottom surface of the groove is a curved surface.

[0012] Furthermore, in the above technical solution, the polyethylene particle abnormal screening device also includes: a distributor, which distributes the polyethylene particles to the conveyor belt so that each groove accommodates a polyethylene particle.

[0013] Furthermore, in the above technical solution, the polyethylene particle abnormal screening device also includes: a mechanical arm, which can move relative to the conveyor belt, and a plurality of feature extractors are arranged at the end of the mechanical arm; and a collector, which is used to collect particles falling from the drop port.

[0014] Furthermore, in the above technical solution, the feature extractor also includes: an inner cylinder, which is arranged between the high-speed camera and the multiple lifting rods; and an outer cylinder, which is arranged around the outside of the multiple lifting rods, and the diameter of the outer cylinder is the same as the diameter of the groove.

[0015] According to the second aspect of the present invention, the present invention provides a screening method for polyethylene particles using an abnormal screening device such as any one of the above-mentioned technical solutions, including the steps of: S100 moving multiple feature extractors so that the multiple feature extractors correspond one-to-one to a group of grooves on the conveyor belt; S200 changing the posture of the particles in the grooves to obtain image information of the particles in the grooves under different postures; S300 identifying abnormal particles based on the acquired image information; S400 discharging the identified abnormal particles from a drop port; S500 after a preset time interval, moving multiple feature extractors so that the multiple feature extractors correspond one-to-one to the next group of grooves on the conveyor belt; repeating the above steps S200~S500.

[0016] Furthermore, in the above technical solution, the screening method also includes the step of: distributing the particles into respective grooves, each groove accommodating one particle.

[0017] Furthermore, in the above technical solution, in step S200, the frequency of acquiring image information is at least 10 times per second.

[0018] Furthermore, in the above technical solution, when spot information exists in the image information, the corresponding particles are identified as abnormal particles.

[0019] Compared with the prior art, the present invention has one or more of the following beneficial effects:

[0020] 1. Through the coordinated design of the groove and the feature extractor, images of particles in different postures can be obtained, thereby achieving all-round detection of particles, greatly improving the accuracy and efficiency of identifying abnormal particles.

[0021] 2. A drop port is set at the bottom of the groove to discard and collect the identified abnormal particles in time, and the normal particles are collected after reaching the end of the conveyor belt, automatically realizing the identification and sorting process of abnormal particles.

[0022] 3. The bottom surface of the groove adopts a curved surface design, which makes it easier for particles to change their posture and ensures that all surfaces of abnormal particles are detected.

[0023] 4. A hook made of elastic material is provided at the bottom of the lifting rod. After the hook touches the bottom of the groove, it tilts slightly inward, making it easier to move the particles in the groove.

[0024] 5. The feature extractor is provided with an inner cylinder and an outer cylinder. The inner cylinder can provide protection for the high-speed camera, and the outer cylinder can provide protection for the lifting rod and can also limit the particles in the groove.

[0025] 6. High-speed cameras can capture image information of particles changing their posture, thereby obtaining a full range of polyethylene particle appearance characteristics without the need for particles to remain stationary for photography at different positions.

[0026] 7. Different recognition accuracies can be set according to different production requirements, for example, by setting the shooting frequency, shooting resolution and other parameters of the high-speed camera.

[0027] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, and to make the above and other purposes, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of a polyethylene particle abnormal screening device according to one embodiment of the present invention.

[0029] Figure 2 Schematic diagram of the distribution of a feature extractor according to an embodiment of the present invention.

[0030] Figure 3 Schematic diagram of the structure of a feature extractor according to one embodiment of the present invention.

[0031] Figure 4 It is a schematic diagram of the cross-sectional structure of a feature extractor according to one embodiment of the present invention.

[0032] Description of main reference numerals:

[0033] 10-conveyor belt, 11-groove, 111-collector, 20-feature extractor, 21-high-speed camera, 22-lifting rod, 221-hook, 23-inner cylinder, 24-outer cylinder, 25-mounting plate, 30-mechanical arm, 31-end, 32-base. DETAILED DESCRIPTION

[0034] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0035] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0036] In this document, for the convenience of description, spatial relative terms such as "below", "below", "down", "above", "above", "upper", etc. may be used to describe the relationship between one element or feature and another element or feature in the accompanying drawings. It should be understood that the spatial relative terms are intended to include different directions of objects in use or operation in addition to the directions drawn in the drawings. For example, if the object in the figure is turned over, the elements described as being "below" or "below" other elements or features will be oriented "above" the elements or features. Therefore, the exemplary term "below" can include both below and above. Objects may also have other orientations (rotated 90 degrees or other orientations) and the spatial relative terms used in this document should be interpreted accordingly.

[0037] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to limit a specific position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can also be interchangeable.

[0038] like Figures 1 to 4 As shown, the abnormal screening device for polyethylene particles according to a specific embodiment of the present invention comprises a conveyor belt 10, on which a plurality of grooves 11 are distributed in a matrix, and a drop opening (not shown in the figure) that can be opened and closed is provided at the bottom of the groove 11. For example, as Figure 1 As shown, the grooves 11 can be arranged in three rows on the conveyor belt 10, but the present invention is not limited thereto. The plurality of feature extractors 20 can move relative to the conveyor belt 10. For example, the plurality of feature extractors 20 can be arranged on the end 31 of the robot arm 30 and move relative to the conveyor belt 10 as the robot arm 30 moves. The distribution of the plurality of feature extractors 20 can be referred to Figure 2 As shown, it can be a 3×3 matrix, so that it corresponds to a group of 3×3 grooves 11. Each feature extractor 20 includes a high-speed camera 21 and a plurality of lifting rods 22. The high-speed camera 21 can collect image information of particles in the corresponding groove; the plurality of lifting rods 22 are distributed in a circle around the high-speed camera 21, and the lifting rods 22 move up and down to change the posture of the particles in the corresponding groove. The controller (not shown in the figure) is connected to the conveyor belt 10 and the plurality of feature extractors 20 in communication, and the controller can open the drop port according to the image information obtained by the high-speed camera 21.

[0039] Further, in one or more exemplary embodiments of the present invention, the lower end of the lifting rod 22 is provided with a hook 221 (refer to Figure 4As shown). Exemplarily, the hook 221 is made of an elastic material, preferably a transparent material, such as transparent silicone, but the present invention is not limited thereto. When the lifting rod 22 drives the hook 221 to move downward, the hook 221 touches the bottom of the groove 11, and through elastic deformation, the hook 221 can be slightly tilted inward along the bottom of the groove 11. Further, in one or more exemplary embodiments of the present invention, adjacent lifting rods 22 of the feature extractor 20 can move up and down at intervals; multiple lifting rods 22 can also rotate around the high-speed camera 21.

[0040] Further, in one or more exemplary embodiments of the present invention, the diameter of the circle formed by the plurality of lifting rods is the same as the maximum size of the particle. Since a soft hook 221 is provided at the lower end of the lifting rod 22, for the same lifting rod 22, the position of the tip of the hook 221 is closer to the center of the circle than the position of the lifting rod 22, so the diameter of the circle formed by the tip of the hook 221 must be smaller than the diameter of the circle formed by the lifting rod 22, that is, smaller than the maximum size of the particle. This ensures that the hook can definitely touch the particle and change its posture through movement.

[0041] Further, in one or more exemplary embodiments of the present invention, the bottom surface of the groove 11 can be designed as a curved surface, but it should be understood that the present invention is not limited thereto. The bottom surface of the groove 11 can be a flat surface.

[0042] Furthermore, in one or more exemplary embodiments of the present invention, the polyethylene particle abnormal screening device further includes a distributor (not shown in the figure), which distributes the polyethylene particles onto the conveyor belt so that each groove accommodates one polyethylene particle.

[0043] Furthermore, in one or more exemplary embodiments of the present invention, the polyethylene particle abnormal screening device also includes a mechanical arm 30, and a plurality of feature extractors 20 are disposed at an end 31 of the mechanical arm 30. The mechanical arm 30 can move relative to the conveyor belt 10 to drive the plurality of feature extractors 20 to correspond one by one to a group of grooves 11. Exemplarily, the plurality of feature extractors 20 can be directly mounted on the end 31 of the mechanical arm 30, or can be mounted through a mounting plate 25. Exemplarily, the mechanical arm 30 can be supported by a base 32, but the present invention is not limited thereto. Figure 1 In the illustrated embodiment, the mechanical arm 30 is independently provided with the conveyor belt 10. It should be understood that the present invention is not limited thereto, and the bottom of the mechanical arm may also be provided on the conveyor belt. Further, in one or more exemplary embodiments of the present invention, a collector 111 is provided under the upper surface of the conveyor belt 10 to collect particles dropped from the drop port.

[0044] Further, in one or more exemplary embodiments of the present invention, the feature extractor 20 is provided with an inner cylinder 23 between the high-speed camera 21 and the plurality of lifting rods 22; and an outer cylinder 24 is provided around the outer sides of the plurality of lifting rods 22. For example, the diameter of the outer cylinder 24 is the same as the diameter of the groove 11. The lower end of the inner cylinder 23 is flush with the lens of the high-speed camera 21 to protect the high-speed camera 21. The lower end of the outer cylinder 24 can be at the same height as the lower end of the inner cylinder 23, or it can be lower than the lower end of the inner cylinder 23. When the feature extractor 20 is aligned with the groove 11, the outer cylinder 24 can just cover the groove 11, or it can leave a small distance from the groove 11, and the distance is preferably such that the polyethylene particles cannot pass through, thereby protecting the lifting rods 22 and limiting the polyethylene particles in the groove 11. For example, the inner cylinder 23 and the outer cylinder 24 can be made of transparent materials to observe the movement state of the particles in the groove, and to avoid the situation that the light source is blocked during the shooting process of the high-speed camera 21, which affects the shooting illumination.

[0045] According to a second aspect of the present invention, the present invention provides a screening method using the polyethylene particle abnormal screening device of the present invention, the screening method comprising the steps of:

[0046] S100 moves the plurality of feature extractors so that the plurality of feature extractors correspond one to one with a group of grooves on the conveyor belt;

[0047] S200 changes the posture of the particles in the groove to obtain image information of the particles in the groove in different postures;

[0048] S300 identifies abnormal particles based on the acquired image information;

[0049] S400 discharges the identified abnormal particles from the drop port;

[0050] S500 moves the plurality of feature extractors after a preset time interval, so that the plurality of feature extractors correspond one by one to the next group of grooves on the conveyor belt;

[0051] Repeat the above steps S200 to S500.

[0052] Further, in one or more exemplary embodiments of the present invention, the screening method further comprises the step of distributing the particles into respective grooves, each groove accommodating one particle.

[0053] Further, in one or more exemplary embodiments of the present invention, in step S200, the frequency of acquiring the image information is at least 10 times per second.

[0054] Further, in one or more exemplary embodiments of the present invention, when there is spot information in the image information, the corresponding particles are identified as abnormal particles. Exemplarily, the spot information is black spots or spots of other colors.

[0055] The present invention is described in more detail below by way of specific embodiments. It should be understood that the present invention is not limited thereto.

[0056] Example 1

[0057] refer to Figures 1 to 4 As shown, the polyethylene particle abnormal screening device of this embodiment includes a conveyor belt 10, a mechanical arm 30 and nine feature extractors 20 arranged on the end 31 of the mechanical arm 30. The conveyor belt 10 is provided with a plurality of grooves 11, and the plurality of grooves 11 are divided into three rows. The nine feature extractors 20 are distributed in a 3×3 matrix, and can correspond to a group of 3×3 grooves 11 one by one each time. In this embodiment, the feature extractor 20 is detachably connected to the end 31 of the mechanical arm 30 through a mounting plate 25.

[0058] A high-speed camera 21 is provided at the center of each feature extractor 20, with a maximum resolution of 1280×1024 pixels and a maximum frame rate of 500fps. Eight lifting rods 22 are distributed in a circle around the high-speed camera 21, and a hook 221 is provided at the lower end of each lifting rod 22, and the hook 221 is made of transparent silicone. The lifting rod 22 can move up and down, and can also rotate around the high-speed camera 21. The high-speed camera 21 is provided with an inner cylinder 23, and the lifting rod 22 is provided with an outer cylinder 24, which is made of transparent material and has the same diameter as the groove 11.

[0059] The robotic arm 30 is supported by a base 32, and its end 31 can move synchronously with the conveyor belt 10 to ensure that the feature extractor 20 corresponds one-to-one with a group of grooves within one detection cycle. The end 31 of the robotic arm 30 can also move relative to the conveyor belt 10, so as to make the feature extractor 20 correspond one-to-one with the next group of grooves.

[0060] The polyethylene particle abnormal screening device of this embodiment can automatically complete the abnormal identification and sorting of polyethylene particles after setting relevant parameters. The working process is as follows:

[0061] The polyethylene granules are distributed into the grooves 11 of the conveyor belt 10 and transported at a constant speed by the conveyor belt 10;

[0062] The feature extractor 20 on the end 31 of the robot arm 30 corresponds one-to-one with a set of grooves 11;

[0063] The lifting rod 22 of the feature extractor 20 rotates around the high-speed camera 21 and moves vertically up and down at intervals, and the hook 221 touches the polyethylene particles in the groove 11 to change the posture of the polyethylene particles; at the same time, the high-speed camera 21 captures the image information of the polyethylene particles ten times per second and transmits it to the controller in real time;

[0064] If black spots or other color spots are found in the image information, the corresponding polyethylene particles are identified as abnormal particles, and the controller locates the groove 11 where the abnormal particles are located and opens its drop opening, allowing the abnormal particles to fall into the collector 111, and then closes the drop opening;

[0065] The other particles in this group of grooves are collected after the conveyor belt 10 reaches the end;

[0066] Move the robot arm 30 so that the feature extractor 20 on the end 31 corresponds one-to-one with the next group of grooves, and repeat the above process.

[0067] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. Any simple modifications, equivalent changes and modifications made to the above exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A polyethylene particle abnormal screening device, characterized in that: include: A conveyor belt having a plurality of grooves arranged in a matrix, wherein the bottom of each groove is provided with a drop opening that can be opened and closed; A plurality of feature extractors, which are movable relative to the conveyor belt so as to correspond one-to-one with a group of the grooves, each of the feature extractors comprising: a high-speed camera that collects image information corresponding to the particles in the groove; and A plurality of lifting rods are distributed in a circle around the high-speed camera, and the lifting rods move up and down to change the posture of the particles in the corresponding grooves; a hook is provided at the lower end of the lifting rod, and the hook is made of elastic material; the plurality of lifting rods rotate around the high-speed camera; and A controller is communicatively connected with the conveyor belt and the plurality of feature extractors, and the controller opens the drop opening according to the image information acquired by the high-speed camera.

2. The abnormal screening device for polyethylene particles according to claim 1, characterized in that: Adjacent lifting rods of the feature extractor move up and down at intervals.

3. The abnormal screening device for polyethylene particles according to claim 1, characterized in that: The diameter of the circle surrounded by the plurality of lifting rods is the same as the maximum size of the particles.

4. The abnormal screening device for polyethylene particles according to claim 1, characterized in that: The bottom surface of the groove is a curved surface.

5. The abnormal screening device for polyethylene particles according to claim 1, characterized in that: Also includes: A distributor distributes particles onto the conveyor belt so that each of the grooves contains one particle.

6. The abnormal screening device for polyethylene particles according to claim 1, characterized in that: Also includes: A mechanical arm capable of moving relative to the conveyor belt, wherein the plurality of feature extractors are arranged at an end of the mechanical arm; as well as A collector is used to collect particles dropped from the drop port.

7. The abnormal screening device for polyethylene particles according to claim 1, characterized in that: The feature extractor also includes: an inner cylinder disposed between the high-speed camera and the plurality of lifting rods; and The outer cylinder is arranged around the outer sides of the plurality of lifting rods, and the diameter of the outer cylinder is the same as the diameter of the groove.

8. A screening method using the polyethylene particle abnormal screening device according to any one of claims 1 to 7, characterized in that: Includes steps: S100 moves the plurality of feature extractors so that the plurality of feature extractors correspond one-to-one to a group of grooves on the conveyor belt; S200 changes the posture of the particles in the groove to obtain image information of the particles in the groove in different postures; S300 identifies abnormal particles based on the acquired image information; S400 discharges the identified abnormal particles from the drop port; S500, after a preset time interval, moving the plurality of feature extractors so that the plurality of feature extractors correspond one-to-one to the next group of grooves on the conveyor belt; Repeat the above steps S200 to S500.

9. The screening method according to claim 8, characterized in that: Also includes the steps: The particles are distributed into the recesses, each recess accommodating one particle.

10. The screening method according to claim 8, characterized in that: In the step S200, the image information is acquired at a frequency of at least 10 times per second.

11. The screening method according to claim 8, characterized in that: When spot information exists in the image information, the corresponding particles are identified as abnormal particles.

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