Polyethylene wrapping film quality detection equipment and detection method

Abstract

The application relates to the technical field of wrapping film detection, and discloses polyethylene wrapping film quality detection equipment and a detection method, which comprises wrapping film production equipment; a wrapping film cutting and shifting assembly for cutting and flattening the free end of the wrapping film is arranged on one side of the wrapping film production equipment; and the wrapping film cutting and shifting assembly comprises a transfer mechanism for transferring the cut wrapping film; the equipment can cut and detect the film section before each time of winding the wrapping film through the cutting and shifting assembly; the mode of sampling detection of finished products in traditional production is completely changed; 100 percent online detection of the wrapping film is realized; the risk of unqualified whole batch products caused by sampling and missed detection is greatly reduced; and various functions such as cutting, transfer, tensile strength detection, shrinkage rate detection and surface defect observation are highly integrated in an automatic system.

Description

Technical Field

[0001] This invention relates to the field of stretch film testing technology, specifically to a polyethylene stretch film quality testing device and testing method. Background Technology

[0002] Polyethylene (PE) stretch film, as a plastic packaging material widely used in industrial packaging, logistics transportation and cargo storage, has the core function of tightly and securely wrapping loose goods into a whole unit by utilizing its good stretching and shrinking properties, so as to improve transportation efficiency, prevent goods from falling, waterproof and dustproof, and reduce packaging costs.

[0003] With the surge in market demand and the diversification of production processes, the inconsistent quality of stretch film has become a key factor restricting packaging efficiency and cost control.

[0004] However, existing polyethylene stretch film quality testing equipment still has the following problems: 1. Traditional quality inspection usually involves sampling inspection after or during mass production. This "post-production" or "probabilistic" inspection carries a huge risk. If the sampled products fail to represent the whole, the entire batch of products may have quality problems, resulting in a batch of defective products and causing huge losses. 2. Traditional strength and shrinkage tests need to be performed on different specialized equipment. The process involves multiple handling, clamping and positioning, which is cumbersome, time-consuming and labor-intensive, with extremely low testing efficiency, and cannot meet the pace of high-speed production lines. 3. Deformations such as stretching and shrinking are difficult to observe and quantify precisely with the naked eye, easily leading to subjective errors. Furthermore, observing defects in transparent films requires high levels of lighting and strong visual acuity, making them prone to fatigue and errors. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a polyethylene stretch film quality testing device and method, mainly to solve the problem that traditional quality testing usually involves sampling inspections after or during mass production, and that traditional strength, shrinkage rate, and other tests need to be performed on different specialized equipment.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A polyethylene stretch film quality inspection device includes a stretch film production device. A stretch film cutting and shifting assembly is provided on one side of the stretch film production device for cutting and flattening the free end of the stretch film. The stretch film cutting and shifting assembly includes a transfer mechanism for transferring the cut stretch film. Below the stretch film cutting and shifting assembly is a stretch film quality inspection assembly for strength testing of the cut stretch film. Above the stretch film quality inspection assembly is a color-coded display assembly for easy observation of the test results. A second image sensor for observing the cut stretch film is installed on one side of the stretch film quality inspection assembly.

[0007] As a further embodiment of the present invention, the stretch film cutting and shifting assembly includes a support frame disposed at the film outlet end of the stretch film production equipment. Two first slide rails are symmetrically and fixedly connected to the top surface of the support frame. A first linkage plate is slidably connected to the top surface of the first slide rails via a slider. A first electric push rod is mounted on the top surface of the first linkage plate. A first positioning frame is disposed below the first linkage plate. The push rod of the first electric push rod passes through the first linkage plate and is fixedly connected to the first positioning frame. Two positioning rails are symmetrically connected to the interior of the first positioning frame via a rotating shaft. A tension frame is slidably connected inside each positioning rail. The two tension frames are symmetrically arranged with an "L" structure, and a first fixing plate is fixedly connected to the opposite side of each of the two tension frames. A clamping plate is rotatably connected to the surface of the first fixing plate via a torsion spring shaft. The clamping plate is in contact with the first fixing plate. A second fixing plate is fixedly connected to the bottom surface of each clamping plate. A groove is formed on the surface of one of the clamping plates, and a cutting blade is slidably connected inside the groove.

[0008] As a further embodiment of the present invention, each clamp plate is symmetrically fixedly connected with two sets of damping mechanisms on the side away from the tension frame. A set of damping mechanisms is fixedly connected to the side of the clamp plate that is in contact with the first fixing plate, and the damping mechanism is located between the two sets of damping mechanisms. Each set of damping mechanisms consists of multiple rubber blocks arranged along the axis.

[0009] As a further embodiment of the present invention, a servo motor is mounted on the side of the first positioning frame, the output shaft of the servo motor passes through the servo motor and is fixedly connected to one of the positioning rails, and two electromagnetic locks are symmetrically mounted on the side of the first positioning frame, the pins of the electromagnetic locks are in contact with the positioning rails.

[0010] As a further embodiment of the present invention, the transfer mechanism includes a motor installed on the side of the support frame, the output shaft of the motor is fixedly connected to a lead screw via a coupling, and the first linkage plate is threadedly connected to the lead screw via a threaded cylinder. Two slotted photoelectric switches are installed on the side of the support frame, and the two slotted photoelectric switches correspond to corresponding workstations.

[0011] As a further embodiment of the present invention, the stretch film quality inspection component includes a worktable disposed below the support frame. A limiting groove is formed on the surface of the worktable, and the positioning rail is placed inside the limiting groove. A fixed slide is fixedly connected inside the worktable. Two connecting platforms are symmetrically slidably connected above the fixed slide. A second linkage plate is fixedly connected to the top surface of each connecting platform. The two second linkage plates are inserted into the corresponding second fixed plates. A connecting frame is fixedly connected to one side of each connecting platform. A first cylinder is disposed on one side of the fixed slide. The two connecting frames are fixedly connected to the piston and housing of the first cylinder, respectively.

[0012] As a further embodiment of the present invention, a second slide rail is provided below the worktable, and a second positioning frame is slidably connected to the surface of the second slide rail via a slider. A second electric push rod is provided on one side of the second slide rail, and the push rod of the second electric push rod is fixedly connected to the second positioning frame. A first image sensor is installed at the top of the second positioning frame, and the lens of the first image sensor faces the limiting groove.

[0013] As a further embodiment of the present invention, the coloring display component includes a third slide rail fixedly connected to the top surface of the workbench, a carriage slidably connected to the surface of the third slide rail via a slider, a third electric push rod fixedly connected to the top surface of the workbench, the push rod of the third electric push rod being fixedly connected to the carriage, a second cylinder mounted on the surface of the carriage, a first positioning slide rail fixedly connected to the surface of the carriage, two positioning blocks symmetrically slidably connected inside the first positioning slide rail, and the piston of the second cylinder being fixedly connected to the two positioning blocks, a marker pen slidably connected inside each positioning block, a finger cylinder mounted on the top surface of the carriage, a second positioning slide rail fixedly connected to the piston end of the finger cylinder, and two second positioning slide rails slidably connected to the second positioning slide rail via a slider.

[0014] As a further embodiment of the present invention, the second image sensor is disposed below the first positioning frame, the second image sensor is fixedly connected to the worktable via a connecting frame, and the lens of the second image sensor faces the first positioning frame.

[0015] A method for testing the quality of polyethylene stretch film includes the following steps: The stretch film cutting and shifting assembly not only has a highly efficient cutting function, but also can quickly and smoothly process the free end of the stretch film, preparing it for subsequent inspection. The stretch film quality inspection component is the core of this equipment. It adopts advanced inspection technology and can accurately measure key indicators such as tensile strength, tear strength and shrinkage strength of stretch film, providing a scientific basis for evaluating the quality of stretch film. The color display component can display transparent colored lines on the surface of a transparent stretch film, allowing operators to see the test results intuitively, which greatly improves the efficiency and accuracy of the test. The second image sensor uses a high-definition camera and image processing technology to carefully observe the cut stretch film, helping operators to discover potential defects or problems, thereby ensuring that each roll of stretch film meets quality requirements.

[0016] Compared with the prior art, the present invention provides a polyethylene stretch film quality testing device and testing method, which has the following beneficial effects: 1. This invention, through the cutting and shifting component, enables the equipment to cut and inspect the film segment before each winding of the stretch film, completely changing the traditional sampling inspection mode of finished products in production. This achieves 100% online inspection of the stretch film, greatly reducing the risk of the entire batch of products being unqualified due to missed sampling inspections, and improving the consistency and reliability of product quality from the source.

[0017] 2. This invention highly integrates multiple functions, including cutting, transportation, tensile strength testing, shrinkage rate testing, and surface defect observation, into a single automated system. This integrated design avoids the cumbersome process of multiple handling, equipment replacement, and repositioning required in traditional testing, significantly improving testing efficiency, shortening the testing cycle, and reducing errors that may be introduced by multiple operations, thus ensuring the accuracy and reliability of the test data.

[0018] 3. By embedding the detection process into the production line and performing it in real time, the system can immediately issue an alarm or even automatically stop production once a quality problem is detected in the stretch film. This real-time feedback mechanism enables problems to be detected and dealt with in a timely manner, effectively preventing the continuous production of unqualified products, reducing raw material waste and economic losses, and realizing intelligent control of the production process.

[0019] 4. This invention utilizes a first image sensor for non-contact deformation observation and a marker with a soft tip for marking, both of which fall under the category of non-destructive testing. This means that while completing the quality assessment, the tested wrapping film sample itself will not suffer physical damage.

[0020] 5. The present invention uses a second image sensor to target the stretch film, so as to avoid defects such as wrinkles and deformation of the stretch film before detection due to environmental factors, thereby ensuring the accuracy and reliability of the detection results.

[0021] 6. This invention transforms the microscopic deformation or fracture location of the material under stress into a macroscopic change that is clearly visible to the naked eye by drawing colored reference lines on a transparent wrapping film. This intuitive visualization effect enables operators to quickly and accurately judge the test results, greatly improving the intuitiveness of the test and the efficiency of the judgment.

[0022] 7. By adopting a vertical spatial layout and modular design, this invention compactly integrates components such as cutting and shifting, quality inspection, and color display. This design effectively saves the equipment's floor space, which is especially advantageous for production workshops with limited space, maximizing functionality within a limited space. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the front three-dimensional structure of a polyethylene wrapping film quality inspection device proposed in this invention; Figure 2 This is a three-dimensional structural diagram of the rear side of a polyethylene stretch film quality testing device proposed in this invention. Figure 3 This is a schematic diagram of the first slide rail and the first linkage plate structure of a polyethylene wrapping film quality inspection device proposed in this invention; Figure 4 This is a schematic diagram of the first fixing plate and clamping plate structure of a polyethylene stretch film quality testing device proposed in this invention; Figure 5 This is a schematic diagram of the clamping plate and the second fixing plate structure of a polyethylene stretch film quality testing device proposed in this invention; Figure 6 This is a schematic diagram of the second electric push rod and the second positioning frame structure of a polyethylene wrapping film quality inspection device proposed in this invention; Figure 7 This is a schematic diagram of the first positioning slide rail and marker pen structure of a polyethylene stretch film quality inspection device proposed in this invention; Figure 8 This is a schematic diagram of the fixed slide and connecting table structure of a polyethylene wrapping film quality testing device proposed in this invention; Figure 9 This is a schematic diagram of the positioning rail and tensioning frame structure of a polyethylene wrapping film quality inspection device proposed in this invention; Figure 10 This invention provides a polyethylene stretch film quality testing device. Figure 4 A schematic diagram of the cross-sectional structure of part A; Figure 11 This invention provides a polyethylene stretch film quality testing device. Figure 5 A schematic diagram of the cross-sectional structure of section B; Figure 12 This is a flowchart of the testing process for a polyethylene stretch film quality testing device proposed in this invention.

[0024] In the picture: 1. Stretch film production equipment; 2. Stretch film cutting and shifting assembly; 21. Support frame; 22. First slide rail; 23. First linkage plate; 24. First electric push rod; 25. First positioning frame; 26. Positioning rail; 27. Tensioning frame; 28. First fixing plate; 29. ​​Clamping plate; 210. Rubber block; 211. Slide groove; 212. Cutting blade; 213. Motor; 214. Electromagnetic lock; 215. Servo motor; 216. Second fixing plate; 217. Slotted photoelectric switch; 3. Stretch film quality inspection assembly; 31. Workbench; 32. Limiting groove; 33. Fixed slide; 34. First cylinder; 35. Second linkage plate; 36. Connecting platform; 37. Second slide rail; 38. Second electric push rod; 39. Second positioning frame; 310. First image sensor; 4. Color display component; 41. Third slide rail; 42. Third electric push rod; 43. Carriage; 44. Second cylinder; 45. First positioning slide rail; 46. Marker pen; 47. Finger cylinder; 48. Second positioning slide rail; 5. Second image sensor. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0026] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] Please see Figures 1-12 As shown, a polyethylene stretch film quality inspection device includes a stretch film production device 1. A stretch film cutting and shifting component 2 is provided on one side of the stretch film production device 1 for cutting and flattening the free end of the stretch film. The stretch film cutting and shifting component 2 includes a transfer mechanism for transferring the cut stretch film. A stretch film quality inspection component 3 for strength testing of the cut stretch film is provided below the stretch film cutting and shifting component 2. A color display component 4 is provided above the stretch film quality inspection component 3 to facilitate clear observation of the test results. A second image sensor 5 for observing the cut stretch film is installed on one side of the stretch film quality inspection component 3.

[0029] In this equipment, the stretch film production device 1 serves as the main frame, providing a stable and reliable support platform for the entire testing process. Its design considers both ease of operation and equipment durability, ensuring long-term stability. Furthermore, its ingeniously designed transfer mechanism accurately moves the cut stretch film to the designated location for the next strength test. The color display component 4, an observation display device, is cleverly positioned above the strength testing mechanism, allowing operators to directly view the test results, significantly improving testing efficiency and accuracy.

[0030] S1. The stretch film cutting and shifting assembly 2 not only has a high-efficiency cutting function, but can also quickly and smoothly process the free end of the stretch film, preparing it for subsequent inspection; S2. The stretch film quality inspection component 3 is the core part of the equipment. It adopts advanced inspection technology and can accurately measure key indicators such as tensile strength, tear strength and shrinkage strength of stretch film, providing a scientific basis for evaluating the quality of stretch film. S3. The color display component 4 can display transparent colored lines on the surface of the transparent stretch film, allowing operators to see the test results intuitively, which greatly improves the efficiency and accuracy of the test. S4. The second image sensor 5 uses a high-definition camera and image processing technology to carefully observe the cut stretch film, helping operators to find possible defects or problems, thereby ensuring that each roll of stretch film meets quality requirements.

[0031] To solve the technical problem of cutting and flattening stretch film, this invention employs a stretch film cutting and shifting assembly 2, which includes a support frame 21 installed at the film outlet end of the stretch film production equipment 1. Two first slide rails 22 are symmetrically and fixedly connected to the top surface of the support frame 21. A first linkage plate 23 is slidably connected to the top surface of the first slide rails 22 via a slider. A first electric push rod 24 is installed on the top surface of the first linkage plate 23. A first positioning frame 25 is installed below the first linkage plate 23. The push rod of the first electric push rod 24 passes through the first linkage plate 23 and is fixedly connected to the first positioning frame 25. The inner... The part is symmetrically connected to two positioning rails 26 via a pivot. Each positioning rail 26 has a tension frame 27 slidably connected inside. The two tension frames 27 are symmetrically arranged with an "L" structure. The opposite sides of the two tension frames 27 are fixedly connected to a first fixing plate 28. The surface of the first fixing plate 28 is rotatably connected to a clamping plate 29 via a torsion spring shaft. The clamping plate 29 and the first fixing plate 28 are in close contact with each other. The bottom surface of each clamping plate 29 is fixedly connected to a second fixing plate 216. One of the clamping plates 29 has a groove 211 on its surface. A cutting blade 212 is slidably connected inside the groove 211.

[0032] A servo motor 215 is mounted on the side of the first positioning frame 25. The output shaft of the servo motor 215 passes through the servo motor 215 and is fixedly connected to one of the positioning rails 26. Two electromagnetic locks 214 are symmetrically mounted on the side of the first positioning frame 25. The pins of the electromagnetic locks 214 are in contact with the positioning rails 26.

[0033] When the stretch film needs to be inspected, the stretch film production equipment 1 first produces the stretch film. Then, force is applied to the clamping plate 29 on the side without the cutting blade 212. The clamping plate 29 will rotate around the torsion spring shaft. The free end of the stretch film is then inserted between the opened first fixing plate 28 and the clamping plate 29. Then, the force applied to the clamping plate 29 is released. The clamping plate 29 will then be in contact with the first fixing plate 28 due to the torsion spring shaft. At this time, the stretching frame 27 faces downward. Therefore, the first fixing plate 28 and the clamping plate 29 holding the free end of the stretch film are located on the side closer to the stretch film production equipment 1. Then, the servo motor 215 is activated. The output shaft of the servo motor 215 will drive the positioning rail 26 to rotate 180° clockwise inside the first positioning frame 25. Then, the pins of the two electromagnetic locks 214 spring back. The pin is then engaged with the positioning rail 26, thus limiting the positioning rail 26 and preventing it from shaking. At this time, the free end of the stretch film is located on the side away from the stretch film production equipment 1, and the stretch film covers the top of the positioning rail 26. Then, force is applied to another clamping plate 29 to insert the stretch film between another first fixing plate 28 and clamping plate 29. Then, force is applied to the cutting blade 212 to make the cutting blade 212 move laterally inside the slide groove 211, thereby cutting the stretch film. The stretch film is then cut. The force on clamping plate 29 is then released, so that another first fixing plate 28 and clamping plate 29 can hold the stretch film. At this time, the stretch film is laid flat on the top of the positioning rail 26.

[0034] This cutting method allows for cutting inspection before each winding of the film, avoiding sampling inspection in traditional testing and reducing the possibility of a decrease in batch pass rate.

[0035] This innovative testing method allows for real-time inspection before each winding. If a quality problem is found in the stretch film, production can be stopped immediately for adjustments, effectively preventing the entire batch from being reworked or scrapped due to a few defective products.

[0036] To address the technical challenge of stabilizing the cut-off wrapping film, this invention employs a method where each clamping plate 29 has two sets of damping mechanisms symmetrically fixedly connected to the side away from the tensioning frame 27, and a set of damping mechanisms is fixedly connected to the side of the clamping plate 29 that is in contact with the first fixing plate 28. This damping mechanism is located between the two sets of damping mechanisms, and each set of damping mechanisms consists of multiple rubber blocks 210 arranged along the axis.

[0037] These damping mechanisms play an important role when clamping the stretch film. When the clamping plate 29 and the first fixing plate 28 are in contact with each other to clamp the stretch film, the damping mechanism located on the contacting side of the clamping plate 29 and the first fixing plate 28 can effectively increase the friction between the two and the stretch film, so that the stretch film is clamped more firmly and avoids slippage or loosening during subsequent operations.

[0038] To solve the technical problem of transferring the cut wrapping film to the work station, the present invention adopts a transfer mechanism including a motor 213 installed on the side of the support frame 21. The output shaft of the motor 213 is fixedly connected to a lead screw through a coupling, and the first linkage plate 23 is threadedly connected to the lead screw through a threaded cylinder. Two slotted photoelectric switches 217 are installed on the side of the support frame 21, and the two slotted photoelectric switches 217 correspond to the corresponding work stations.

[0039] When the motor 213 is started, its output shaft drives the lead screw to rotate. Since the first linkage plate 23 is threadedly connected to the lead screw through a threaded cylinder, the first linkage plate 23 will move horizontally along the two first slide rails 22 during the rotation of the lead screw, thereby realizing the smooth transfer of the cut wrapping film from one station to another. When moving to different stations, the electromagnetic lock 214 can make the first positioning frame 25 adjust its height appropriately according to different stations. The slotted photoelectric switch 217 installed on the side of the support frame 21 can be used to precisely control and limit the movement position of the first linkage plate 23, ensuring the accuracy and stability of the transfer process.

[0040] In actual operation, this transfer mechanism has demonstrated significant advantages. Its horizontal movement design ensures the stretch film remains stable during transfer, preventing damage or misalignment due to improper handling. Simultaneously, the precise control and limit function of the slotted photoelectric switch 217 further improves the accuracy and stability of the transfer, ensuring the stretch film accurately reaches the designated workstation and providing strong support for subsequent production processes.

[0041] It should be noted that the 217 slot-type photoelectric switch, model EE-SX671, operates on the principle of having an infrared transmitter and an infrared receiver mounted face-to-face on opposite sides of a U-shaped slot. When unobstructed, the receiver receives the infrared light emitted by the transmitter. When an object passes through the slot and blocks the light, the receiver cannot receive the light signal, thus triggering the switch to generate an electrical signal change. This can be configured according to specific needs, and will not be elaborated upon here.

[0042] To address the technical problem of inspecting the stretched film after it has been cut, this invention employs a film stretching quality inspection component 3, which includes a worktable 31 positioned below a support frame 21. A limiting groove 32 is formed on the surface of the worktable 31, and a positioning rail 26 is placed inside the limiting groove 32. A fixed slide 33 is fixedly connected inside the worktable 31. Two connecting platforms 36 are symmetrically slidably connected above the fixed slide 33. A second linkage plate 35 is fixedly connected to the top surface of each connecting platform 36. Both second linkage plates 35 are inserted into the corresponding second fixed plates 216. A connecting frame is fixedly connected to one side of each connecting platform 36. A first cylinder 34 is provided on one side of the fixed slide 33, and the two connecting frames are fixedly connected to the piston and housing of the first cylinder 34, respectively.

[0043] A second slide rail 37 is provided below the worktable 31. A second positioning frame 39 is slidably connected to the surface of the second slide rail 37 via a slider. A second electric push rod 38 is provided on one side of the second slide rail 37. The push rod of the second electric push rod 38 is fixedly connected to the second positioning frame 39. A first image sensor 310 is installed at the top of the second positioning frame 39. The lens of the first image sensor 310 faces the limiting groove 32.

[0044] When the stretch film needs to be inspected, the stretch film is first moved above the limiting groove 32 by the transfer mechanism. Then, the positioning rail 26 is placed inside the limiting groove 32 by the first electric push rod 24. When the positioning rail 26 is inserted into the limiting groove 32, the two second linkage plates 35 will be inserted into the corresponding second fixing plates 216, thereby limiting the stretching frame 27. Then, the second electric push rod 38 is activated to move the second positioning frame 39 from the surface of the second slide rail 37 toward the worktable 31 until the lens of the first image sensor 310 is aligned with the stretch film, thus completing the preliminary steps of quality inspection.

[0045] When the stretching rate of the stretch film is tested, the first cylinder 34 is activated, and the piston end of the first cylinder 34 extends outward. At this time, the two connecting platforms 36 move in opposite directions on the surface of the fixed slide 33 through the connecting frame. At this time, the two second linkage plates 35 drive the two stretching frames 27 to extend outward inside the two positioning rails 26 through the second fixed plate 216, so that the two ends of the stretch film are stretched in opposite directions until the specified requirements are met, and then it can be stopped.

[0046] The first image sensor 310 will activate the high-definition shooting function to take detailed pictures of the surface of the stretch film from all angles. The captured image data will be quickly transmitted to the back-end analysis system. The system has built-in advanced image recognition algorithms and defect detection models. Through in-depth analysis and comparison of the image data, it can be observed whether the surface of the stretch film is broken when the stretch film is tested for elongation, thus realizing the detection of the stretch film elongation.

[0047] When the shrinkage rate of the stretch film is detected, after the stretch film is stretched, the push rod of the first electric push rod 24 drives the first positioning frame 25 to move upward until the second linkage plate 35 disengages from the inside of the second fixed plate 216, thus releasing the limit on the stretching frame 27. At this time, the stretch film will begin to shrink back due to the characteristics of its own material, and the two stretching frames 27 will approach each other inside the positioning rail 26. The first image sensor 310 will clearly observe the shrinkage rate of the stretch film through the high-definition shooting function, thus realizing the detection of the shrinkage rate of the stretch film.

[0048] This integrated testing method offers numerous advantages. First, it significantly improves testing efficiency. Previously, different equipment and processes were needed to test the quality, elongation, and shrinkage of stretch film; now, these can be completed sequentially within a single device, saving considerable time and labor costs. Second, it reduces sources of error during testing. Since continuous testing is conducted under the same environment and conditions, it avoids deviations in test results caused by equipment differences or environmental changes, resulting in more accurate and reliable data. Third, the device is relatively easy to operate; staff can master the testing process with minimal training, reducing the professional skill requirements for operators and further enhancing the feasibility and convenience of the overall testing work. Moreover, this integrated testing device has a small footprint, making it an ideal choice for testing locations with limited space. It enables multiple testing functions within a confined space, improving space utilization. In conclusion, performing three tests on stretch film using a single device provides an efficient, accurate, and convenient solution for stretch film quality assessment and production control.

[0049] The elongation rate must meet the following two conditions simultaneously: 1. No breakage: The images captured by the first image sensor 310 were processed by the analysis system and confirmed that no breakage, cracks or holes appeared on the surface of the wrapping film throughout the stretching process.

[0050] 2. Elongation rate meets the standard: The elongation rate calculated by the system ((stretched length - initial length) / initial length × 100%) meets or exceeds the product's preset technical standard (e.g., ≥300%).

[0051] The acceptable standard for shrinkage rate is that the shrinkage rate of the stretch film ((stretched length - shrinkage length) / stretched length × 100%) falls within the preset standard range of the product (e.g., 15% ± 5%).

[0052] Unacceptable conditions: The calculated shrinkage rate is higher than the upper limit of the standard range (excessive shrinkage) or lower than the lower limit of the standard range (insufficient shrinkage).

[0053] Coordination with the colored lines: The shrinkage rate is calculated by measuring the change in distance between the two colored line segments after the shrinkage stabilizes. This result should be verified against the calculation results of the image analysis system.

[0054] To address the technical issue of more clearly displaying the color during testing, this invention employs a color display component 4, which includes a third slide rail 41 fixedly connected to the top surface of a workbench 31. A slide frame 43 is slidably connected to the surface of the third slide rail 41 via a slider. A third electric push rod 42 is fixedly connected to the top surface of the workbench 31, and the push rod of the third electric push rod 42 is fixedly connected to the slide frame 43. A second cylinder 44 is mounted on the surface of the slide frame 43, and a first positioning slide rail 45 is fixedly connected to the surface of the slide frame 43. Two positioning blocks are symmetrically slidably connected inside the first positioning slide rail 45, and the piston of the second cylinder 44 is fixedly connected to the two positioning blocks. A marker pen 46 is slidably connected inside each positioning block. A finger cylinder 47 is mounted on the top surface of the slide frame 43, and a second positioning slide rail 48 is fixedly connected to the piston end of the finger cylinder 47. The two second positioning slide rails 48 are slidably connected to each other via a slider.

[0055] Because the stretch film is transparent, it is difficult to observe during inspection. Therefore, the third electric push rod 42 is activated, pushing the carriage 43 to slide along the surface of the third slide rail 41. During the sliding of the carriage 43, the second cylinder 44 mounted on its surface moves accordingly until the two markers 46 are above the stretch film. Then, the finger cylinder 47 is activated, and its piston end drives the markers 46 to slide downwards inside the two positioning blocks via the second positioning slide rail 48 until the tips of the markers 46 are in contact with the stretch film. The piston of the second cylinder 44 drives the two positioning blocks to slide symmetrically inside the first positioning slide rail 45, causing the two markers 46 to draw two coaxial colored lines on the surface of the stretch film. When the stretch film is stretched, the two colored lines extend to both ends. When the stretch film breaks, a gap appears in the middle of the colored line segment. When the stretch film shrinks, the two ends of the colored line segment move towards the center, thus facilitating inspection.

[0056] Due to the inherent characteristics of the marker 46, the tip of the marker 46 has a weak piercing ability, ensuring that the wrapping film will not be damaged during the process of sliding out the line.

[0057] To solve the technical problem of observing the surface of the wrapping film, the present invention employs a second image sensor 5 positioned below the first positioning frame 25. The second image sensor 5 is fixedly connected to the worktable 31 via a connecting frame, and the lens of the second image sensor 5 faces the first positioning frame 25.

[0058] When the stretch film is laid flat above the positioning rail 26, the second image sensor 5 below is facing the stretch film. In order to avoid defects such as wrinkles and deformation of the stretch film before detection due to environmental factors, the accuracy and reliability of the detection results are ensured.

[0059] It should be noted that both the first image sensor 310 and the second image sensor 5 use CCD cameras. Digital cameras that use charge-coupled devices (CCDs) as image sensors convert optical scenes into digital image signals and output them as raw pixel matrices. Then, in conjunction with subsequent software algorithms, image recognition is achieved. Those skilled in the art can set these parameters according to actual needs, which will not be elaborated here.

[0060] The quality inspection process for polyethylene stretch film consists of the following steps: S1: When the stretch film needs to be inspected, firstly, the stretch film production equipment 1 produces the stretch film. Then, force is applied to the clamping plate 29 on the side without the cutting blade 212. The clamping plate 29 will rotate around the torsion spring shaft. Then, the free end of the stretch film is inserted between the opened first fixing plate 28 and the clamping plate 29. Then, the force applied to the clamping plate 29 is released. The clamping plate 29 will fit against the first fixing plate 28 due to the torsion spring shaft. At this time, the stretching frame 27 faces downward. Therefore, the first fixing plate 28 and the clamping plate 29 holding the free end of the stretch film are located on the side closer to the stretch film production equipment 1. Then, the servo motor 215 is started. The output shaft of the servo motor 215 will drive the positioning rail 26 to rotate 180° clockwise inside the first positioning frame 25. Then, the pins of the two electromagnetic locks 214 are activated. The pop-out mechanism causes the pin to engage with the positioning rail 26, thereby limiting the positioning rail 26 and preventing it from wobbling. At this time, the free end of the stretch film is located on the side away from the stretch film production equipment 1, and the stretch film covers the top of the positioning rail 26. Then, force is applied to another clamping plate 29 to insert the stretch film between another first fixing plate 28 and clamping plate 29. Then, force is applied to the cutting blade 212 to make the cutting blade 212 move laterally inside the slide groove 211, thereby cutting the stretch film. The stretch film is then cut. The force applied to clamping plate 29 is then released, so that another first fixing plate 28 and clamping plate 29 can hold the stretch film. At this time, the stretch film is laid flat on the top of the positioning rail 26. S2: These damping mechanisms play an important role when clamping the wrapping film. When the clamping plate 29 and the first fixing plate 28 are in contact with each other to clamp the wrapping film, the damping mechanism located on the side of the clamping plate 29 and the first fixing plate 28 that are in contact with each other can effectively increase the friction between the two and the wrapping film, so that the wrapping film is clamped more firmly and avoids slippage or loosening during subsequent operations; S3: When the motor 213 is started, its output shaft will drive the lead screw to rotate. Since the first linkage plate 23 is connected to the lead screw through the threaded cylinder, the first linkage plate 23 will move horizontally along the two first slide rails 22 during the rotation of the lead screw, thereby realizing the smooth transfer of the cut wrapping film from one station to another. When moving to different stations, the electromagnetic lock 214 can make the first positioning frame 25 adjust its height appropriately according to different stations. The slotted photoelectric switch 217 installed on the side of the support frame 21 can be used to precisely control and limit the movement position of the first linkage plate 23 to ensure the accuracy and stability of the transfer process. S4: When it is necessary to inspect the stretch film, firstly, the stretch film is moved above the limiting groove 32 by the transfer mechanism, and then the positioning rail 26 is placed inside the limiting groove 32 by the first electric push rod 24. When the positioning rail 26 is inserted into the limiting groove 32, the two second linkage plates 35 will be inserted into the corresponding second fixing plates 216, thereby limiting the stretching frame 27. Then, the second electric push rod 38 is activated to move the second positioning frame 39 on the surface of the second slide rail 37 toward the worktable 31 until the lens of the first image sensor 310 is aligned with the stretch film, thus completing the preliminary steps of quality inspection. S5: When the stretch film stretch rate is detected, the first cylinder 34 is activated, and the piston end of the first cylinder 34 extends outward. At this time, the two connecting platforms 36 move in opposite directions on the surface of the fixed slide 33 through the connecting frame. At this time, the two second linkage plates 35 drive the two stretching frames 27 to extend outward inside the two positioning rails 26 through the second fixed plate 216, so that the two ends of the stretch film are stretched in opposite directions until the specified requirements are met and then stop. The first image sensor 310 will activate the high-definition shooting function to take detailed pictures of the surface of the stretch film from all directions. The captured image data will be quickly transmitted to the back-end analysis system. The system has built-in advanced image recognition algorithms and defect detection models. Through in-depth analysis and comparison of image data, it can be observed whether the surface of the stretch film is broken when the stretch rate is detected, thus realizing the detection of the stretch film stretch rate. S6: When the shrinkage rate of the stretch film is detected, after the stretch film is stretched, the push rod of the first electric push rod 24 drives the first positioning frame 25 to move upward until the second linkage plate 35 disengages from the inside of the second fixed plate 216, thus releasing the limit on the stretching frame 27. At this time, the stretch film will begin to shrink due to the characteristics of its own material, and the two stretching frames 27 will approach each other inside the positioning rail 26. The first image sensor 310 will clearly observe the shrinkage rate of the stretch film through the high-definition shooting function, thus realizing the detection of the shrinkage rate of the stretch film. S7: Because the stretch film is transparent, it is not easy to observe during inspection. Therefore, the third electric push rod 42 is activated. The push rod of the third electric push rod 42 starts to work, pushing the slide 43 to slide along the surface of the third slide rail 41. During the sliding of the slide 43, the second cylinder 44 installed on its surface moves accordingly until the two markers 46 are above the stretch film. Then, the finger cylinder 47 is activated. The piston end of the finger cylinder 47 drives the markers 46 to slide downward inside the two positioning blocks through the second positioning slide rail 48 until the tip of the markers 46 is in contact with the stretch film. The piston of the second cylinder 44 drives the two positioning blocks to slide symmetrically inside the first positioning slide rail 45, so that the two markers 46 will draw two colored lines on the surface of the stretch film along the same axis. When the stretch film is stretched, the two colored lines will extend to both ends. When the stretch film breaks, a blank will appear in the middle of the colored line segment. When the stretch film shrinks, the two ends of the colored line segment will move towards the center, thus making it easier to inspect. S8: When the stretch film is laid flat above the positioning rail 26, the second image sensor 5 below is facing the stretch film. In order to avoid defects such as wrinkles and deformation of the stretch film before detection due to environmental factors, the accuracy and reliability of the detection results are ensured.

[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A polyethylene stretch film quality inspection device, comprising stretch film production equipment (1), characterized in that, The stretch film production equipment (1) is provided with a stretch film cutting and shifting assembly (2) on one side for cutting and flattening the free end of the stretch film, and the stretch film cutting and shifting assembly (2) includes a transfer mechanism for transferring the cut stretch film. Below the stretch film cutting and shifting assembly (2) is a stretch film quality detection assembly (3) for detecting the strength of the cut stretch film, and above the stretch film quality detection assembly (3) is a color display assembly (4) for easy observation of the detection results. A second image sensor (5) for observing the cut stretch film is installed on one side of the stretch film quality detection assembly (3). The stretch film cutting and shifting assembly (2) includes a support frame (21) disposed at the film outlet end of the stretch film production equipment (1). Two first slide rails (22) are symmetrically and fixedly connected to the top surface of the support frame (21). A first linkage plate (23) is slidably connected to the top surface of the first slide rails (22) via a slider. A first electric push rod (24) is mounted on the top surface of the first linkage plate (23). A first positioning frame (25) is disposed below the first linkage plate (23). The push rod of the first electric push rod (24) passes through the first linkage plate (23) and is fixedly connected to the first positioning frame (25). Two... Each positioning rail (26) has a tension frame (27) slidably connected inside. The two tension frames (27) are symmetrically arranged with an "L" structure. The opposite sides of the two tension frames (27) are fixedly connected with a first fixing plate (28). The surface of the first fixing plate (28) is rotatably connected with a clamping plate (29) through a torsion spring shaft. The clamping plate (29) is in close contact with the first fixing plate (28). The bottom surface of each clamping plate (29) is fixedly connected with a second fixing plate (216). A groove (211) is opened on the surface of one of the clamping plates (29). A cutting blade (212) is slidably connected inside the groove (211). The wrapping film quality inspection component (3) includes a worktable (31) disposed below the support frame (21). A limiting groove (32) is formed on the surface of the worktable (31). The positioning rail (26) is placed inside the limiting groove (32). A fixed slide (33) is fixedly connected inside the worktable (31). Two connecting platforms (36) are symmetrically slidably connected above the fixed slide (33). A second linkage plate (35) is fixedly connected to the top surface of each connecting platform (36). The two second linkage plates (35) are inserted into the corresponding second fixed plates (216). A connecting frame is fixedly connected to one side of each connecting platform (36). A first cylinder (34) is provided on one side of the fixed slide (33). The two connecting frames are fixedly connected to the piston and the housing of the first cylinder (34) respectively.

2. The polyethylene stretch film quality testing equipment according to claim 1, characterized in that, Each clamp (29) has two sets of damping mechanisms fixedly connected symmetrically on the side away from the tension frame (27). The side of the clamp (29) that is in contact with the first fixing plate (28) is fixedly connected to a set of damping mechanisms, and the damping mechanism is located between the two sets of damping mechanisms. Each set of damping mechanisms consists of multiple rubber blocks (210) arranged along the axis.

3. The polyethylene stretch film quality testing equipment according to claim 1, characterized in that, A servo motor (215) is mounted on the side of the first positioning frame (25). The output shaft of the servo motor (215) passes through the servo motor (215) and is fixedly connected to one of the positioning rails (26). Two electromagnetic locks (214) are symmetrically mounted on the side of the first positioning frame (25). The pin of the electromagnetic lock (214) is in contact with the positioning rail (26).

4. The polyethylene stretch film quality testing equipment according to claim 1, characterized in that, The transfer mechanism includes a motor (213) installed on the side of the support frame (21). The output shaft of the motor (213) is fixedly connected to a lead screw through a coupling. The first linkage plate (23) is threadedly connected to the lead screw through a threaded cylinder. Two slotted photoelectric switches (217) are installed on the side of the support frame (21), and the two slotted photoelectric switches (217) correspond to the corresponding work positions.

5. The polyethylene stretch film quality testing equipment according to claim 1, characterized in that, A second slide rail (37) is provided below the worktable (31). A second positioning frame (39) is slidably connected to the surface of the second slide rail (37) by a slider. A second electric push rod (38) is provided on one side of the second slide rail (37). The push rod of the second electric push rod (38) is fixedly connected to the second positioning frame (39). A first image sensor (310) is installed on the top of the second positioning frame (39). The lens of the first image sensor (310) faces the limiting groove (32).

6. The polyethylene stretch film quality testing equipment according to claim 5, characterized in that, The coloring display component (4) includes a third slide rail (41) fixedly connected to the top surface of the workbench (31). A carriage (43) is slidably connected to the surface of the third slide rail (41) via a slider. A third electric push rod (42) is fixedly connected to the top surface of the workbench (31). The push rod of the third electric push rod (42) is fixedly connected to the carriage (43). A second cylinder (44) is mounted on the surface of the carriage (43). A first positioning slide rail (45) is fixedly connected to the surface of the carriage (43). Two positioning blocks are symmetrically slidably connected inside the first positioning slide rail (45). The piston of the second cylinder (44) is fixedly connected to the two positioning blocks. A marker pen (46) is slidably connected inside each positioning block. A finger cylinder (47) is mounted on the top surface of the carriage (43). A second positioning slide rail (48) is fixedly connected to the piston end of the finger cylinder (47). The two second positioning slide rails (48) are slidably connected to the second positioning slide rail (48) via a slider.

7. The polyethylene stretch film quality testing equipment according to claim 6, characterized in that, The second image sensor (5) is located below the first positioning frame (25). The second image sensor (5) is fixedly connected to the worktable (31) through a connecting frame, and the lens of the second image sensor (5) faces the first positioning frame (25).

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