CN-122016829-A - Automatic detection system and detection method for pits on surface of plastic master batch

CN122016829ACN 122016829 ACN122016829 ACN 122016829ACN-122016829-A

Abstract

The invention relates to the technical field of master batch production quality detection, in particular to an automatic detection system and a detection method for pits on the surface of a plastic master batch, wherein the detection system comprises a sheet forming device, a sheet transmission device, a visual detection system and a data processing system, the sheet forming device forms the plastic master batch according to a set temperature and a set pressure to obtain a sheet, the sheet material is continuously transmitted to the visual detection system by the sheet material transmission device according to the set interval and the set speed, the visual detection system performs visual detection on the sheet material one by one, and the characteristic parameters of the pit defect area and the space position of the pit defect area can be obtained by analyzing and processing the image detected by the visual detection system through the data processing system. The invention can realize real-time, continuous and online monitoring of the plastic master batch production process, effectively eliminate the hysteresis of detection, improve the detection efficiency and the degree of automation, and simultaneously improve the detection precision and the detection reliability.

Inventors

ZHU YIN
YU XINGXING
LU MING
Xi Houfang
YIN LONG
LI JIANJUN
TAO SHAN

Assignees

金发科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260206

Claims (10)

1. The automatic detection system for the pits on the surface of the plastic master batch is characterized by comprising a sheet forming device, a sheet conveying device, a visual detection system and a data processing system: the sheet forming device is a screw extruder with a slit-shaped mouth die and is used for extruding and forming the plastic master batch to obtain sheets with target sizes, and the sheet forming device is positioned at one end of the sheet conveying device; the sheet conveying device comprises a servo motor with an encoder arranged inside and a conveyor belt driven by the servo motor according to a set rotating speed, wherein the conveyor belt is used for receiving sheets obtained by extrusion molding of the sheet molding device and conveying a plurality of sheets to the visual detection system according to a set interval and a set speed; The visual detection system is positioned at the other end of the sheet conveying device and comprises an image acquisition component and an image acquisition triggering component which are in signal connection, wherein the image acquisition triggering component is in signal connection with the encoder, the image acquisition triggering component is used for sending a signal for carrying out line scanning to the image acquisition component, the image acquisition component is positioned above the conveying belt and used for acquiring a sheet image, and the direction of a line in the line scanning is vertical to the conveying direction of the sheet; The data processing system is used for receiving the sheet image and analyzing and processing the sheet image to obtain characteristic parameters of the pit defect area and the spatial position of the pit defect area, wherein the characteristic parameters comprise area, perimeter and roundness.
2. The automatic detection system of pits on a plastic master batch surface according to claim 1, wherein the image acquisition assembly comprises an illumination device and an imaging device positioned on two sides of a plumb line: An included angle is arranged between the central axis of the lighting device and the plumb line ; An included angle is arranged between the central axis of the imaging device and the plumb line ; Wherein, the , 。
3. The automatic detection system of plastic master batch surface pits according to claim 2, further comprising a mounting bracket, a first fixed frame, and a second fixed frame: the mounting bracket is provided with a first mounting groove and a second mounting groove, and the second mounting groove is higher than the first mounting groove; The lighting device is slidably mounted in the first mounting groove through the first fixing frame; the imaging device is slidably mounted in the second mounting groove through a second fixing frame; the illumination device and the imaging device are both positioned above the conveyor belt.
4. The plastic master batch surface pockmark automatic detection system of claim 3, wherein the first fixed frame and the second fixed frame each comprise a fixed cross bar, a fixed buckle and a limiting piece: the end part of the fixed cross rod is slidably arranged in the first mounting groove or the second mounting groove; The limiting piece comprises a first connecting part fixedly connected with the fixed cross rod, a second connecting part fixedly connected with the lighting device or the imaging device and a third connecting part arranged between the first connecting part and the second connecting part, an included angle theta is formed between the second connecting part and the third connecting part, ; The fixing buckle is fixedly connected with the second connecting part, and the fixing buckle is fixedly connected with the lighting device or the imaging device.
5. The automatic detection system of pits on the surface of a plastic master batch according to claim 1, wherein the data processing system comprises an image preprocessing sub-module, a feature extraction and segmentation sub-module and a defect judging sub-module: the image preprocessing sub-module comprises an interested region extraction module and a noise suppression module, wherein the interested region extraction module is used for processing the sheet image and extracting to obtain a first image, and the noise suppression module is used for filtering noise in the first image to obtain a second image with pock edge details reserved; The characteristic extraction and segmentation sub-module is used for processing the second image, separating the pit defect area from the background and connecting the broken pit defect area to restore the true form of the pits; The defect judging submodule is used for analyzing the characteristic parameters of the pit defect area and comparing the characteristic parameters with a preset threshold value to obtain defect classification.
6. The automatic detection system for pits on the surface of a plastic master batch according to claim 5, further comprising a data storage module and an alarm module: the data storage module is used for recording and storing the space coordinates and the characteristic parameters of the pit defect area; and the alarm module is used for alarming and prompting when the number of the pits in the accumulated set length exceeds a set threshold value.
7. The automatic detection system for pits on the surface of plastic master batch according to any one of claims 1 to 6, wherein a plurality of air cooling devices are uniformly distributed above the sheet conveying device.
8. The automatic detection system for surface pits of plastic master batch according to any one of claims 1 to 6, further comprising a cleaning protection structure, wherein at least the sheet conveying device and the visual detection system are located inside the cleaning protection structure.
9. The automatic detection method for the pits on the surface of the plastic master batch is realized based on the automatic detection system for the pits on the surface of the plastic master batch according to any one of claims 1 to 8, and is characterized by comprising the following steps: adding the plastic master batch into a screw extruder, and extruding and molding by the screw extruder to obtain sheets with target sizes; The sheet material is fallen on a conveyor belt, and a plurality of sheet materials are conveyed to the visual detection system by the conveyor belt according to a set interval and a set speed; the image acquisition triggering component receives signals of the encoder to trigger the image acquisition component to perform line scanning on the surface of the sheet to obtain a sheet image; And the data processing step is to analyze and process the sheet image to obtain the characteristic parameters of the pit defect area and the spatial position of the pit defect area.
10. The method for automatically detecting pits on the surface of a plastic master batch according to claim 9, wherein the step of data processing comprises the steps of: Determining the edge of the sheet through a self-adaptive threshold segmentation algorithm, removing a background area by combining Blob analysis, and extracting a first image; filtering the salt and pepper noise and Gaussian noise in the region-of-interest image by adopting a non-local mean value filtering algorithm, and reserving the edge details of the pits to obtain a second image; calculating the local standard deviation and the gradient amplitude of the second image to construct a texture feature map, and carrying out binarization treatment on the map by using a region growing algorithm to obtain pit defects from the background; And the defect judging step is to extract the characteristic parameters of each pit defect area by adopting a connected domain analysis technology, compare the characteristic parameters with a preset judging threshold value and identify and classify the pit defect areas.

Description

Automatic detection system and detection method for pits on surface of plastic master batch Technical Field The invention relates to the technical field of master batch production quality detection, in particular to an automatic detection system and an automatic detection method for pits on the surface of a plastic master batch. Background The plastic master batch is used as a key raw material in the processing of plastic products, and the appearance quality of the plastic master batch directly influences the performance and quality of the final product. In various opaque master batch products, surface pits are a common appearance defect, usually manifested by the presence of microscopic depressions or impurity spots on the particle surface. The existence of the pits not only affects the attractiveness of the product, but also becomes a stress concentration point in the material, so that the mechanical property of the material is weakened. For PVC (polyvinyl chloride) master batch, the PVC master batch is widely applied to the fields of wire and cable sheaths, building materials, films and the like, has particularly strict requirements on surface quality, and is particularly important for detecting pits in the production process of PVC cable materials. If pits exist on the surface of the cable material, in the subsequent extrusion processing, the defect position is extremely easy to cause uneven thickness of an insulating layer or a sheath layer, becomes a weak point under the action of an electric field, causes local electric breakdown accidents, seriously threatens the use safety and service life of the cable, and finally has serious influence on the quality of a terminal product. At present, the quality control of the pits on the surface of the PVC master batch in the industry is carried out in a mainstream detection mode which takes over the traditional offline and destructive detection flow, wherein a small amount of master batch samples are firstly sampled at regular time on a production line and then sent to a laboratory for analysis, and in the laboratory, the samples are completely observed by operators through naked eyes or by means of simple amplifying equipment, the number of the pits on the surface of the master batch is manually distinguished and counted, and the approximate size of the pits is estimated. The traditional pock detection method has a series of technical problems to be solved, on one hand, the whole process usually needs to take up to four hours or even longer from sampling, sample feeding and laboratory preparation to final manual analysis to give results, the serious hysteresis of the detection results enables quality feedback information to be far behind the actual production rhythm, the production line is in a 'blind production' state without effective quality monitoring in most of the time, the accurate quality management requirements of modern manufacturing enterprises on real-time monitoring and instant intervention of the production process cannot be met, due to the delay of quality information feedback, when the detection results finally show quality abnormality, a large number of unqualified products are produced in the period, the unqualified products are extremely easy to flow into downstream clients, and the clients are caused to question and complaint the quality of the whole materials, so that huge economic loss and long-term brand reputation risks are brought to the production enterprises, on the other hand, the detection method is high in labor cost and low in efficiency, meanwhile, the risks of unstable interpretation results and poor repeatability are brought by excessively relying on manual experience are brought about by operators, and different operators or operators can possibly give different samples to different experience in different times. Disclosure of Invention The invention aims to solve the problems of poor repeatability, high labor cost and low efficiency caused by lagging detection results and unstable interpretation results of a plastic master batch surface pockmark automatic detection system in the prior art, and provides the plastic master batch surface pockmark automatic detection system which can realize real-time online detection, eliminate the lagging of detection, improve the detection efficiency and the automation degree, and simultaneously improve the detection precision and the detection reliability. In order to solve the technical problems, the invention adopts the following technical scheme: the automatic detection system comprises a sheet forming device, a sheet transmission device, a visual detection system and a data processing system, wherein the sheet forming device is a slit-shaped screw extruder of a die and is used for extruding and forming plastic master batches to obtain sheets with target sizes, the sheet forming device is positioned at one end of the sheet transmission device, the sheet transmission device comprises a ser