Liquid food packaging pressure resistance online detection system

Abstract

The present application relates to a kind of liquid food packaging pressure resistance online detection system, including product conveyor, manipulator, detection bag transfer unit and pressure detection unit, product conveyor is used to convey finished packaging box;Detection bag transfer unit includes storage box from top to bottom, bag dispenser and bag opener, provide bottom opening, top closed packaging bag for pressure detection unit;Pressure detection unit includes movable clamping part, hot-press sealing part and at least a pair of oppositely arranged suction cups, manipulator extracts finished packaging box on product conveyor, and is placed into clamping part;Two suction cups can receive packaging bag from bag opener, clamping part can be moved between two suction cups, and finished packaging box is lifted into packaging bag;Hot-press sealing part can be moved below packaging bag, for hot-press sealing packaging bag opening;The outside of two suction cups is connected with pressure adjusting device respectively, to provide detection pressure, and the pressure resistance of finished packaging box is detected.

Description

Technical Field

[0001] This invention belongs to the field of liquid food packaging testing technology, specifically relating to an online testing system for the pressure resistance of liquid food packaging. Background Technology

[0002] In the liquid food packaging industry, after filling and sealing, the pressure resistance of the packaging structure needs to be tested to ensure that the packaging seal is intact and that the liquid will not leak due to normal-intensity impacts and compression during subsequent transportation. The most important type of liquid food packaging is three-dimensional box-shaped packaging, such as Tetra Pak cartons. The sealing of three-dimensional box-shaped packaging consists of horizontal and vertical seals. If the seal is poor, the joints of the horizontal and vertical seals will break first during compression. Plastic bag packaging also requires sealing strength testing. Current technology commonly uses sampling inspection methods, which involve sampling from a batch of products and sending the samples to a laboratory for pressure testing to determine the pass rate. While this method is highly accurate, it has a significant time lag. Once a problem is detected, equipment adjustments are needed, meaning that products produced before the adjustments may also have sealing issues, requiring supplementary testing. These defective products result in substantial losses and waste for the company. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides an online pressure resistance testing system for liquid food packaging, comprising a product conveyor belt, a robotic arm, a testing bag transfer unit, and a pressure testing unit. The product conveyor belt is used to transport finished product packaging boxes. The testing bag transfer unit, from top to bottom, includes a storage box, a bag dispenser, and a bag opener, providing the pressure testing unit with a sealed bag that is open at the bottom and closed at the top.

[0004] The pressure detection unit includes a movable clamping part, a heat-sealing part, and at least a pair of opposing suction cups. The robotic arm picks up the finished packaging box from the product conveyor belt and places it into the clamping part; the two suction cups can receive the sealing bag from the bag opener, and the clamping part can move between the two suction cups to lift the finished packaging box into the sealing bag; the heat-sealing part can move to the bottom of the sealing bag to heat-seal the opening of the sealing bag; the outer sides of the two suction cups are respectively connected to an air pressure regulating device to provide detection pressure and detect the pressure resistance of the finished packaging box.

[0005] Optionally, an online inspection workbench is provided next to the product conveyor belt, a robotic arm is provided between the product conveyor belt and the workbench, a vertical equipment wall is provided on the workbench, the inspection bag transfer unit and the first track are installed on the equipment wall, and the bases of the two suction cups are slidably connected to the first track, which can move the position of the suction cups.

[0006] Two recycling bins are located below the workbench to collect qualified and unqualified products after testing, respectively; the workbench is equipped with a second track and a third track, with the clamping part slidingly connected to the second track and the heat-sealing part slidingly connected to the third track.

[0007] Optionally, the storage box contains a series of sealed bags connected end to end, which facilitates continuous release under the pulling force of the bag releaser; the bottom of the storage box is provided with an outlet, allowing a single sealed bag to be pulled out.

[0008] The bag dispenser includes two symmetrically arranged rollers. The central axis of the rollers is horizontal. The two rollers rotate in opposite directions and their surfaces can contact each other. When the bag is between the two rollers, the rotation of the rollers generates friction, which can continuously pull the bag downward.

[0009] The bag opener includes two symmetrically arranged rollers, the central axis of which is horizontal. The two rollers rotate in opposite directions and their surfaces can contact each other. One roller is connected to a drive device, which allows it to move back and forth towards or away from the wall of the device. While pulling down the sealed bag between the two rollers, it can also open the sealed bag, making it easier to pack into the finished product packaging box.

[0010] Further optionally, a cutting device is provided between the bag dispenser and the bag opener to cut off the connection between the bag held by the bag opener and the bag above it.

[0011] The cutting device includes an infrared transmitter, an infrared receiver, a first support rod, a second support rod, a cutting blade, and a second driving device. Both the first and second support rods are horizontally arranged and perpendicular to the equipment wall. One end of the first support rod is connected to the equipment wall, and the other end is equipped with an infrared transmitter. One end of the second support rod is connected to the equipment wall, and the other end is equipped with an infrared receiver. The positions of the infrared transmitter and the infrared receiver correspond to each other.

[0012] The second drive unit is mounted on the equipment wall. The telescopic end of the second drive unit is connected to the cutting blade, which allows the cutting blade to move back and forth in the direction of approaching or moving away from the equipment wall to cut open the connection of the packaging bag.

[0013] Optionally, the sides of the suction cup are connected to the corresponding base via support rods. The inside of the suction cup is hollow. The sides of the two suction cups facing each other are the inner sides, and the sides opposite to the inner sides of the suction cups are the outer sides. The outer sides of the suction cups are connected to an air pressure regulating device via pipes, which can supply or evacuate air from the inside of the suction cups. The inner sides of the suction cups are evenly provided with several hollowed-out sections, so that the internal space of the suction cups is connected to the external space of the suction cups.

[0014] When the air pressure regulating device is evacuating, the two suction cups can hold the descending packaging bag, making it easier to put the finished packaging box into the packaging bag; when the air pressure regulating device is supplying air, the air pressure between the two suction cups squeezes the finished packaging box, enabling pressure detection.

[0015] Further optionally, the hollowed-out portion is vertical, and one hollowed-out portion is composed of several strip-shaped hollowed-out portions and circular hollowed-out portions arranged alternately; in two adjacent hollowed-out portions, the strip-shaped hollowed-out portions and the circular hollowed-out portions are at the same height, that is, hollowed-out portions of the same shape are staggered from each other in the horizontal direction.

[0016] Further optionally, the ratio of the diameter of the circular cutout to the maximum lateral length of the corresponding suction cup is (0.03-0.05):1;

[0017] Within the same hollow section, the ratio of the width of the strip-shaped hollow to the diameter of the circular hollow is (0.6-0.8):1, and the ratio of the longitudinal length of the strip-shaped hollow to the diameter of the circular hollow is 1:1.

[0018] Optionally, the first track is a horizontal strip track located below the bag opener, allowing the two suction cups to move laterally below the bag opener, i.e., to move closer to or further away from each other, thereby clamping the finished product packaging box.

[0019] Optionally, the clamping part includes a clamping seat and an air supply pipe. The clamping seat is slidably connected to the second track on the workbench surface via a telescopic support rod. The bottom of the air supply pipe is connected to the clamping seat, and the top of the air supply pipe is vertically upward. The air supply pipe is hollow inside and is connected to a vacuum pump and an air supply pump in parallel through an air pipe. It can evacuate the air inside the packaging bag to be tested, prepare for pressure testing, and also output air upward to support the packaging bag.

[0020] Optionally, the second track is perpendicular to the device wall and corresponds to the position of the bag opener, so that the clamping seat can be close to or far away from the bottom of the bag opener.

[0021] Optionally, a heat press is provided at the top of the heat-sealing part for heat-sealing the bottom of the packaged bag; the third track is parallel to the second track and is located between the second track and the equipment wall, so that the heat-sealing part can move back and forth under the packaged bag containing the finished product packaging box. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the online pressure resistance testing system for liquid food packaging.

[0023] Figure 2 for Figure 1 A top-down view;

[0024] Figure 3 for Figure 1A side view diagram;

[0025] Figure 4 for Figure 1 A side view diagram of the other side;

[0026] Figure 5 This diagram illustrates how a bag dispenser, bag opener, and suction cup work together to stretch, cut, and attract the sealed bag.

[0027] In the attached diagram, 1-Product conveyor belt, 2-Robot arm, 3-Finished product packaging box, 4-Storage box, 5-Support rod four, 6-Clamping part, 7-Heat sealing part, 8-Suction cup, 9-Rolling wheel one, 10-Rolling wheel two, 11-Workbench, 12-Equipment wall, 13-First track, 14-Second track, 15-Third track, 16-Recycling bin, 17-Infrared transmitter, 18-Infrared receiver, 19-Support rod one, 20-Support rod two, 21-Cut blade, 22-Sealing bag, 23-Support rod three, 24-Hollowed-out part, 25-Strip hollowed-out part, 26-Circular hollowed-out part, 27-Clamping seat, 28-Air supply pipe. Detailed Implementation

[0028] This embodiment provides an online testing system for the pressure resistance of liquid food packaging, such as... Figures 1-5 As shown, it includes a product conveyor belt 1, a robotic arm 2, a detection bag transfer unit and a pressure detection unit. The product conveyor belt 1 is used to transport finished product packaging boxes 3. The detection bag transfer unit includes a storage box 4, a bag dispenser and a bag opener from top to bottom, providing a sealed bag 22 with a bottom opening and a top closing for the pressure detection unit.

[0029] The pressure detection unit includes a movable clamping part 6, a heat-sealing part 7, and at least a pair of opposing suction cups 8. The robot arm 2 picks up the finished packaging box from the product conveyor belt 1 and places it into the clamping part 6. The two suction cups 8 can receive the sealing bag from the bag opener. The clamping part 6 can move between the two suction cups 8 and lift the finished packaging box into the sealing bag. The heat-sealing part 7 can move to the bottom of the sealing bag to heat-seal the opening of the sealing bag. The outer sides of the two suction cups 8 are respectively connected to an air pressure regulating device to provide detection pressure and detect the pressure resistance of the finished packaging box.

[0030] Compared to traditional workshop sampling and laboratory testing, this invention places the pressure testing unit near the product conveyor belt 1, integrating the online testing system into the production process to achieve online testing. The testing principle is as follows: finished product packaging boxes are placed inside a sealing bag, and then the sealing bag is sealed to prevent the packaging box from breaking during pressure testing and causing internal liquid to splash out; then a preset pressure is applied to the sealing bag; products that break are considered defective, while those that do not break are considered acceptable. All tested products are discarded (and cannot be sold). When a defective product is detected, the product conveyor belt 1 stops, and equipment adjustments and debugging are immediately performed to quickly correct the sealing problem of the packaging box at its source.

[0031] Optionally, an online inspection workbench 11 is provided next to the product conveyor belt 1, and a robot arm 2 is provided between the product conveyor belt 1 and the workbench 11. A vertical equipment wall 12 is provided on the workbench 11, and the inspection bag transfer unit and the first track 13 are installed on the equipment wall 12. The bases of the two suction cups 8 are slidably connected to the first track 13, which can move the position of the suction cups 8.

[0032] Two recycling bins 16 are provided below the workbench 11 to collect qualified and unqualified products after testing, respectively; the workbench 11 is provided with a second track 14 and a third track 15, the clamping part 6 is slidably connected to the second track 14, and the hot-press sealing part 7 is slidably connected to the third track 15.

[0033] Optionally, the storage box 4 contains a series of sealed bags connected end to end, which facilitates continuous release under the pulling force of the bag releaser; the bottom of the storage box 4 is provided with an outlet, allowing a single sealed bag to be pulled out.

[0034] The bag dispenser includes two symmetrically arranged rollers 9. The central axis of the rollers 9 is horizontally set. The two rollers 9 rotate in opposite directions and their surfaces can contact each other. When the bag is between the two rollers 9, the rotation of the rollers 9 generates friction, which can continuously pull the bag downward.

[0035] The bag opener includes two symmetrically arranged rollers 10. The central axis of the rollers 10 is horizontal. The two rollers 10 rotate in opposite directions and their surfaces can contact each other. One roller is connected to a drive device 1, which allows it to move back and forth towards or away from the device wall 12. While pulling down the sealed bag between the two rollers 10, it can also open the sealed bag, making it easier to put into the finished product packaging box later.

[0036] Optionally, the storage box 4 has an openable top cover for easy insertion of packaging bags from the top; the outlet at the bottom of the storage box 4 is elongated to control the number of packaging bags pulled out; the storage box 4 is preferably made of a transparent material to facilitate real-time observation of the amount of packaging bags inside for timely replenishment. The storage box 4 is mounted on the side of the equipment wall 12.

[0037] Optionally, the central shaft of the roller 9 is connected to a corresponding motor on the device wall 12, driving the roller 9 to rotate; the right roller 9 rotates counterclockwise and the left roller 9 rotates clockwise, thereby pulling the packaging bag between the two rollers 9 downward.

[0038] Alternatively, the central shaft of one roller 10 is connected to a corresponding motor on the device wall 12; the central shaft of the other roller 10 is connected to a corresponding motor, which is connected to the telescopic end of the drive device 1. The drive device 1 is located on the device wall 12, so that while the roller 10 is rotating, it can also move horizontally toward the device wall 12, thereby breaking open the packaging bag between the two rollers 10.

[0039] The right-side roller 210 rotates counterclockwise, while the left-side roller 210 rotates clockwise, thereby pulling the packaging bag between the two rollers 210 downwards.

[0040] The horizontally movable roller 10 moves only a small distance in the horizontal direction, for example, within 1-5cm. This is to create horizontal friction to open the packaged bag. Therefore, the pressure on the telescopic end of the drive device is not high. Alternatively, a support rod can be installed to support the telescopic end, ensuring that the telescopic end, motor, and roller 10 remain horizontal. The narrow opening of the storage box 4 and the lowered packaged bag are both perpendicular to the equipment wall 12.

[0041] Further optionally, a cutting device is provided between the bag dispenser and the bag opener to cut off the connection between the bag held by the bag opener and the bag above it.

[0042] The cutting device includes an infrared transmitter 17, an infrared receiver 18, a first support rod 19, a second support rod 20, a cutting blade 21, and a second driving device. Both the first support rod 19 and the second support rod 20 are horizontally arranged and perpendicular to the equipment wall 12. One end of the first support rod 19 is connected to the equipment wall 12, and the other end is equipped with an infrared transmitter. One end of the second support rod 20 is connected to the equipment wall 12, and the other end is equipped with an infrared receiver. The positions of the infrared transmitter and the infrared receiver correspond to each other.

[0043] The second drive unit is mounted on the equipment wall 12. The telescopic end of the second drive unit is connected to the cutting blade 21, which allows the cutting blade 21 to move back and forth in the direction of approaching or moving away from the equipment wall 12 to cut open the connection of the packaging bag.

[0044] Optionally, the handle of the cutting blade 21 is connected to the telescopic end of the second drive device, the blade body is parallel to the equipment wall 12, the blade tip points to the first support rod 19 or the second support rod 20, the blade surface of the cutting blade 21 is horizontal, and the blade surface is sharpened on both sides, so that the cutting blade 21 can cut open the connection of the packaging bag when it moves telescopically.

[0045] Optionally, the cutting blade 21 is at the same horizontal level as the infrared transmitter and infrared receiver. When the connection of the packaging bag passes through this horizontal level, the infrared receiver detects the change in the received infrared light, and the control device activates the second drive device to drive the cutting blade 21 to move and cut open the connection of the packaging bag.

[0046] The connection of several sealed bags is similar to that of current roll garbage bags. The connection between two adjacent sealed bags is linear with equally spaced openings. When the cutting blade 21 cuts open the connection, the bottom of the upper sealed bag is open, and the top of the lower sealed bag is sealed, with the sealed part lower than the connection.

[0047] In use, manually pull out the first sealed bag from the bottom, allowing it to pass through the bag dispenser and bag opener. Then, activate rollers 9 and 10 to begin pulling the bag downwards. As the bottom of a sealed bag reaches between rollers 10, one of the rollers begins to move horizontally while rotating, rubbing and opening the bag. The bag continues to move downwards, continuing to be opened. Because the bag moves downwards under the pulling force of the two rollers, the bag between the dispenser and opener is fully expanded due to the tension, facilitating infrared detection. Infrared rays hitting the bag are obstructed, resulting in a weak or non-existent infrared signal received by the infrared receiver.

[0048] When the top of the packaging bag passes the same height as the infrared emitter, some infrared rays pass through the through-hole at the connection and are received by the infrared receiver. The control device receives this change and drives the cutting blade 21 to move, cutting off the connection. The lower packaging bag continues to be conveyed and opened downwards by the roller 2 10, preparing to enter between the two suction cups 8. The upper packaging bag continues to move downwards under the action of the roller 1 9. Then, the lower packaging bag is attracted by the two suction cups 8 and completely detaches from the bag holder, while the upper packaging bag enters downwards between the two roller 2 10, continues to move downwards, and is opened at the same time. The above operation is repeated to continuously convey packaging bags to the pressure detection unit.

[0049] Optionally, the sides of the suction cup 8 are connected to the corresponding base via support rod 23. The inside of the suction cup 8 is hollow. The sides of the two suction cups 8 facing each other are the inner sides, and the sides opposite to the inner sides of the suction cup 8 are the outer sides. The outer sides of the suction cup 8 are connected to an air pressure regulating device via pipes, which can supply or evacuate air from the inside of the suction cup 8. The inner sides of the suction cup 8 are evenly provided with several hollowed-out parts 24, so that the internal space of the suction cup 8 is connected to the external space of the suction cup 8.

[0050] When the air pressure regulating device is evacuating, the two suction cups 8 can hold the descending packaging bag, making it easier to put the finished packaging box into the packaging bag; when the air pressure regulating device is supplying air, the air pressure between the two suction cups 8 squeezes the finished packaging box, which can perform pressure detection.

[0051] Optionally, the inner and outer surfaces of the suction cup 8 are perpendicular to the device wall 12. The suction cup 8 is a flat cube, disc, or ellipse shape. The area of ​​the inner surface of the suction cup 8 is not less than the maximum flat area of ​​the packaging bag, facilitating the attraction of the packaging bag. The maximum flat area of ​​the packaging bag is greater than the maximum side area of ​​the finished packaging box.

[0052] Optionally, the pressure regulating device is located below the workbench 11 and includes a gas cylinder, a gas supply pump, and a vacuum pump. The gas cylinder is connected to the suction cup 8 via a gas pipe and the gas supply pump to supply gas to the suction cup 8. The vacuum pump is connected to the suction cup 8 via a gas pipe to evacuate gas from the suction cup 8. The gas path of the vacuum pump is connected to the suction cup 8 in parallel with the gas path of the gas supply pump, and each is equipped with a gas valve to facilitate separate control of gas supply and evacuation.

[0053] Optionally, the hollowed-out portion 24 is vertical, and one hollowed-out portion 24 is formed by alternating strip-shaped hollows 25 and circular hollows 26; in two adjacent hollowed-out portions 24, the strip-shaped hollows 25 and circular hollows 26 are at the same height, that is, hollows of the same shape are staggered in the horizontal direction.

[0054] Further optionally, the ratio of the diameter of the circular cutout to the maximum lateral length of the corresponding suction cup is (0.03-0.05):1;

[0055] In the same hollow section 24, the ratio of the width of the strip-shaped hollow to the diameter of the circular hollow is (0.6-0.8):1, and the ratio of the longitudinal length of the strip-shaped hollow to the diameter of the circular hollow is 1:1.

[0056] Preferably, all the perforated portions 24 of the two suction cups 8 are the same size, which facilitates a more uniform air passage for the sealing bag and the finished packaging box, and uniform suction and pressure.

[0057] Optionally, the first track 13 is a horizontal strip track and is located below the bag opener, so that the two suction cups 8 can move laterally below the bag opener, that is, move towards or away from each other, to achieve the action of clamping the finished product packaging box.

[0058] Optionally, both ends of the first track 13 extend laterally along the length of the equipment wall 12, away from the detection bag transfer unit, so that after a pair of suction cups 8 clamp the finished product packaging box, they can leave the detection bag transfer unit and go to other positions for pressure testing. The suction cups 8 of other pressure testing units can move along the first track 13 to the bottom of the bag opener to receive the sealing bag and the finished product packaging box, so as to realize continuous testing and improve testing efficiency.

[0059] In one specific implementation, the first track 13 is centered on the detection bag transfer unit, with tracks on both sides of the detection bag transfer unit. A pair of suction cups 8 moves back and forth on the right side of the first track 13, and another pair of suction cups 8 moves back and forth on the left side of the first track 13, without affecting each other. Two recycling bins are provided on the right side below the workbench 11 to collect qualified and unqualified products after testing, respectively. Two recycling bins are also provided on the left side below the workbench 11 to collect qualified and unqualified products after testing, respectively, serving the two pairs of suction cups 8.

[0060] Optionally, the clamping part 6 includes a clamping seat 27 and an air supply pipe 28. The clamping seat 27 is slidably connected to the second track 14 on the surface of the workbench 11 via a telescopic support rod 4 5. The bottom of the air supply pipe 28 is connected to the clamping seat 27, and the top of the air supply pipe 28 is vertically upward. The air supply pipe 28 is hollow inside and is connected to a vacuum pump and an air supply pump in parallel through an air pipe. It can evacuate the air inside the packaging bag to be tested, prepare for pressure testing, and also output air upward to support the packaging bag.

[0061] Alternatively, the clamping seat 27 has a downwardly recessed positioning groove in the center, in which the finished packaging box can be placed, and the finished packaging box is prevented from shaking or tipping over when the clamping seat 27 moves.

[0062] Optionally, the air supply pipe 28 is located at the edge of the positioning groove, which does not affect the placement of the finished product packaging box, but can contact the side of the finished product packaging box to play an auxiliary fixing role, making the moving finished product packaging box more stable. Moreover, the air supply pipe 28 is together with the finished product packaging box, and the air supply pipe 28 enters the sealing bag together with the finished product packaging box. Furthermore, the air supply pipe 28 occupies as little space as possible in the sealing bag, which facilitates the removal of air from the sealing bag as much as possible, which is beneficial for subsequent pressure testing.

[0063] Optionally, the second track 14 is perpendicular to the device wall 12 and corresponds to the position of the bag opener, so that the clamping seat 27 can be close to or far away from the bottom of the bag opener.

[0064] In use, the robotic arm 2 picks up a finished packaging box from the product conveyor belt 1 and places it in the positioning slot of the gripper 27. At this time, the gripping part 6 is located at the end of the second track 14 furthest from the bag opener. After receiving the finished packaging box, the gripping part 6 moves along the second track 14 to below the bag opener. At this time, the top of the gripping part 6 faces a pair of suction cups 8.

[0065] The second roller 10 of the bag opener transports a sealed bag downwards. The bag is open at the bottom and sealed at the top, and is then opened by the roller 10, leaving the bottom open. As the bag passes the top between the two suction cups 8, the distance between the two suction cups 8 decreases but they do not contact the bag. The two suction cups 8 then simultaneously draw air, attracting the two sides of the bottom of the bag. At this time, the top of the bag is still being pulled by the second roller 10, while the bottom is opened by the two suction cups 8, achieving the initial opening of the bag. As the bag continues to descend, the two suction cups 8 stop drawing air and no longer attract the bag. At the same time, the two suction cups 8 move further apart to leave space for the finished packaging box. After the bag detaches from the second roller 10, it falls naturally, at which point the air supply pipe 28 is directly below the bag. When the packaging bag falls between the two suction cups 8 (the tops of the two suction cups 8 can be equipped with infrared transmitters and infrared receivers respectively to detect the position of the packaging bag falling), the air supply pipe 28 supplies air upwards, and the airflow enters the packaging bag from the bottom opening, which plays the role of lifting the packaging bag downwards and temporarily preventing the packaging bag from falling. At this time, the two suction cups 8 simultaneously extract air and suck up the two sides of the packaging bag again, waiting for the finished packaging box, and the air supply pipe 28 stops supplying air.

[0066] The support rod 4 5 extends, feeding the finished packaging box into the sealing bag. The two suction cups 8 move closer together along the first track 13, clamping the two sides of the finished packaging box. The air supply pipe 28 is positioned on the side of the finished packaging box that is not clamped. The support rod 4 5 shortens, and the clamping part 6 moves downward while the air supply pipe 28 evacuates air until the top of the air supply pipe 28 reaches the bottom of the sealing bag. A vacuum pump is then used to remove the air from the sealing bag, and the bag is left to be heat-sealed.

[0067] Optionally, the top of the heat-sealing part 7 is provided with a heat press for heat-sealing the bottom of the packaged bag; the third track 15 is parallel to the second track 14 and is located between the second track 14 and the equipment wall 12, so that the heat-sealing part 7 can move back and forth under the packaged bag containing the finished product packaging box.

[0068] The third track 15 can connect with the second track 14, meaning the third track 15 and the second track 14 are on the same straight line. The hot press moves along the third track 15, starting the hot pressing from one end of the bottom of the sealing bag, moving and pressing simultaneously. At the same time, the air supply pipe 28 moves away from the suction cup 8 along with the clamping part 6, without obstructing the hot press. Finally, the support rod 4 5 retracts, causing the air supply pipe 28 to move downwards while moving away from the suction cup 8, thus detaching from the sealing bag and moving away along the second track 14 to prepare to receive the next finished packaging box. The hot press finally passes completely through the bottom opening of the sealing bag, completing the seal. At this point, the two suction cups 8 clamp the finished packaging box containing the sealing bag, and the inside of the sealing bag has been evacuated, which does not affect the pressure detection.

[0069] The two suction cups 8 move away from the bag holder along the first track 13, and the heat-sealing part 7 resets. The two suction cups 8 wait for the bottom temperature of the sealed bag to drop (or for air cooling). Then, pressure detection begins, and the two suction cups 8 start supplying air, creating air pressure towards each other, with pressure on both sides of the finished product packaging box. If it is a defective product, the finished product packaging box is crushed, liquid enters the sealed bag, and the pressure between the two suction cups 8 decreases instantaneously, which can be detected by the pressure gauge. The finished product packaging box and the sealed bag fall into the defective product recycling bin through the opening on the workbench 11. If it is a qualified product, the finished product packaging box is not crushed, the pressure between the two suction cups 8 remains unchanged, which can be detected by the pressure gauge, and the two suction cups 8 clamp the finished product packaging box and move it above the qualified product recycling bin before discarding the crushed finished product packaging box and the sealed bag.

[0070] Preferably, the top of the bag dispenser, bag opener, and suction cup 8 is provided with a windproof cover to prevent the falling of the sealed bag from being affected by external airflow and to ensure that it can fall smoothly. The bottom of the windproof cover does not affect the movement of the suction cup 8. The infrared transmitter and infrared receiver of the cutting device can be located inside the windproof cover.

[0071] Example 1

[0072] This embodiment provides an online detection system for the pressure resistance of liquid food packaging, which has all the above-mentioned technical features. The features are that the suction cup is a flat cuboid and is placed vertically; the diameter of the circular cutout is 2.5cm, and the ratio of the diameter of the circular cutout to the maximum horizontal length of the corresponding suction cup is 0.03:1; in the same cutout section, the ratio of the width of the strip cutout to the diameter of the circular cutout is 0.6:1, and the ratio of the vertical length of the strip cutout to the diameter of the circular cutout is 1:1.

[0073] Example 2

[0074] This embodiment provides an online detection system for the pressure resistance of liquid food packaging, which is the same as that in Embodiment 1, except that the ratio of the diameter of the circular cutout to the maximum lateral length of the corresponding suction cup is 0.05:1.

[0075] Example 3

[0076] This embodiment provides an online detection system for the pressure resistance of liquid food packaging, which is the same as that in Embodiment 1, except that the ratio of the diameter of the circular cutout to the maximum lateral length of the corresponding suction cup is 0.02:1.

[0077] Example 4

[0078] This embodiment provides an online testing system for the pressure resistance of liquid food packaging, which is the same as that in Embodiment 1, except that the ratio of the width of the strip-shaped cutout to the diameter of the circular cutout is 0.8:1.

[0079] Example 5

[0080] This embodiment provides an online testing system for the pressure resistance of liquid food packaging, which is the same as that in Embodiment 1, except that the ratio of the width of the strip-shaped cutout to the diameter of the circular cutout is 0.5:1.

[0081] Example 6

[0082] This embodiment provides an online detection system for the pressure resistance of liquid food packaging, which is the same as that in Embodiment 1, except that the inner surface of the suction cup is uniformly covered with through holes, and the diameter of the through holes is 2mm.

[0083] In the laboratory, a standard pressure test is performed on sampled finished packaging boxes. Mechanical pressure is applied simultaneously to the two opposite pressure-bearing sides of the finished packaging box. That is, a flat pressure plate is used to squeeze the finished packaging box with a predetermined test pressure to obtain the pass rate of a batch of products.

[0084] Pressure tests were performed on the same batch of products using the systems from Examples 1-6. Because the suction cups in these examples are perforated, the air pressure effect of the suction cups differs from the mechanical pressure effect of the flat pressure plate. Experiments comparing the two testing methods showed that, under the same testing and product conditions, to achieve the same product pass rate as mechanical testing, the suction cup testing air pressure must be greater than the flat pressure plate testing pressure. The testing air pressure differed for suction cups with different perforated sizes. After summing and averaging the testing air pressures of suction cups of various sizes, the average testing air pressure of the suction cups was 1.35 times the testing pressure of the flat pressure plate. The average testing air pressure was used for pressure testing in Examples 1-5, and the resulting product pass rates are shown in Table 1.

[0085]

[0086] In the above formula, A 标 A represents the product pass rate obtained from standard pressure testing, in %; A represents the product pass rate obtained from Examples 1-5, in %.

[0087] Table 1 Comparison of deviation rates between Examples 1-5 and standard tests

[0088] Standard testing 96.0 - Example 1 96.9 0.94 Example 2 95.8 0.21 Example 3 99.0 3.13 Example 4 97.3 1.35 Example 5 98.5 2.60

[0089] Traditional pressure testing techniques involve using a flat sheet to mechanically compress the test surface of the packaging box, or using air pressure to mechanically compress the test surface of the packaging box, so that the test surface is subjected to uniform pressure.

[0090] Mechanical extrusion of flat sheets is not suitable for the system of the present invention because the suction cup of the present invention can also perform an air extraction operation to attract the two opposite sides of the packaging bag, so that the bottom opening of the packaging bag is open and the finished packaging box can easily enter the packaging bag.

[0091] Uniform and complete air pressure detection is also not suitable for the system of the present invention. If the inner side of the suction cup has a complete air pressure outlet, it is not conducive to the suction cup holding the finished packaging box, and when attracting the sealing bag, it is easy to suck the sealing bag in whole or in part into the suction cup, making it difficult to control the position of the sealing bag.

[0092] Those skilled in the art may think of the suction cup form of Embodiment 6, but through experiments, the form of uniformly densely distributed through holes on the inner side of the suction cup makes the air pressure at the location point of the packaging box very small when pressure is applied, resulting in a large pressure at each through hole, forming a needle-like pressure on the packaging box, making the packaging box easy to penetrate, and failing to reflect the pressure situation of the packaging box in most application scenarios, resulting in easily distorted test results.

[0093] The suction cup of this invention features alternating strip-shaped and circular perforations, with the perforations evenly distributed. While not providing absolutely uniform pressure, the pressure is lower than that of a densely perforated type, making it closer to the practical application scenario of packaging boxes. It also attracts the packaging bag more evenly, preventing it from being sucked into the suction cup, and the bag's position on the suction cup is more uniform. The inventors unexpectedly discovered that the alternating arrangement of strip-shaped and circular perforations can create more uniform pressure on the packaging box while expanding the pressure application area. This may be because the edges of the strip-shaped and circular perforations have a certain uniform effect on the force applied in various directions. Further research is needed to determine the specific force application and distribution.

Claims

1. An online detection system for the pressure resistance of liquid food packaging, characterized in that, It includes a product conveyor belt, a robotic arm, a test bag transfer unit, and a pressure detection unit. The product conveyor belt is used to transport finished product packaging boxes. The test bag transfer unit includes a storage box, a bag dispenser, and a bag opener from top to bottom. The test bag transfer unit provides the pressure detection unit with a sealed bag that is open at the bottom and closed at the top. The pressure detection unit includes a movable clamping part, a heat-sealing part, and at least a pair of opposing suction cups. The robotic arm picks up the finished packaging box from the product conveyor belt and places it into the clamping part; the two suction cups can receive the sealing bag from the bag opener, and the clamping part can move between the two suction cups to lift the finished packaging box into the sealing bag; the heat-sealing part can move to the bottom of the sealing bag to heat-seal the opening of the sealing bag; the outer sides of the two suction cups are respectively connected to the air pressure regulating device to provide detection pressure and detect the pressure resistance of the finished packaging box; The suction cup is hollow inside. The sides of the two suction cups facing each other are called the inner sides, and the sides opposite to the inner sides of the suction cups are called the outer sides. The outer sides of the suction cups are connected to a pressure regulating device through pipes, which can supply or evacuate air from the inside of the suction cups. The inner sides of the suction cups are evenly provided with several hollowed-out sections, so that the internal space of the suction cups is connected to the external space of the suction cups. When the regulating air pressure device is evacuating, the two suction cups can hold the descending packaging bag, making it easier to put the finished packaging box into the packaging bag; when the regulating air pressure device is supplying air, the air pressure between the two suction cups squeezes the finished packaging box, enabling pressure detection. The clamping part includes a clamping seat and an air supply pipe. The clamping seat is slidably connected to the second track on the workbench surface via a telescopic support rod. The bottom of the air supply pipe is connected to the clamping seat, and the top of the air supply pipe is vertically upward. The air supply pipe is hollow inside and is connected to a vacuum pump and an air supply pump in parallel through an air pipe. It can evacuate the air inside the packaging bag to be tested to prepare for pressure testing, and can also output air upward to support the packaging bag.

2. The online detection system for the pressure resistance of liquid food packaging according to claim 1, characterized in that, An online inspection workbench is provided next to the product conveyor belt. A robotic arm is provided between the product conveyor belt and the workbench. A vertical equipment wall is provided on the workbench. The inspection bag transfer unit and the first track are installed on the equipment wall. The bases of the two suction cups are slidably connected to the first track, and the two suction cups can move along the first track. Two recycling bins are located below the workbench to collect qualified and unqualified products after testing, respectively; the workbench is equipped with a second track and a third track, with the clamping part slidingly connected to the second track and the hot-pressing sealing part slidingly connected to the third track.

3. The online detection system for the pressure resistance of liquid food packaging according to claim 2, characterized in that, The storage box contains a series of sealed bags connected end to end, and the bottom of the storage box has an outlet that allows a single sealed bag to be pulled out. The bag dispenser includes two symmetrically arranged rollers. The central axis of the rollers is horizontal. The two rollers rotate in opposite directions and their surfaces can contact each other. When the bag is between the two rollers, the rollers can continuously pull the bag downwards. The bag opener includes two symmetrically arranged rollers, the central axis of which is horizontal. The two rollers rotate in opposite directions and their surfaces can contact each other. One roller is connected to a drive device, which allows it to move back and forth towards or away from the wall of the device. While pulling down the sealed bag between the two rollers, it can also open the sealed bag, making it easier to pack into the finished product packaging box.

4. The online detection system for the pressure resistance of liquid food packaging according to claim 3, characterized in that, A cutting device is provided between the bag dispenser and the bag opener to cut off the connection between the bag held by the bag opener and the bag above it. The cutting device includes an infrared transmitter, an infrared receiver, a first support rod, a second support rod, a cutting blade, and a second driving device. Both the first and second support rods are horizontally arranged and perpendicular to the equipment wall. One end of the first support rod is connected to the equipment wall, and the other end is equipped with an infrared transmitter. One end of the second support rod is connected to the equipment wall, and the other end is equipped with an infrared receiver. The positions of the infrared transmitter and the infrared receiver correspond to each other. The second drive unit is mounted on the equipment wall. The telescopic end of the second drive unit is connected to the cutting blade, which allows the cutting blade to move back and forth in the direction of approaching or moving away from the equipment wall to cut open the connection of the packaging bag.

5. The online detection system for the pressure resistance of liquid food packaging according to claim 2, characterized in that, The suction cup is connected to the corresponding base via a support rod.

6. The online detection system for the pressure resistance of liquid food packaging according to claim 5, characterized in that, The hollowed-out portion is vertical, and each hollowed-out portion is composed of several alternating strip-shaped and circular hollowed-out portions; in two adjacent hollowed-out portions, the strip-shaped and circular hollowed-out portions are at the same height, and the hollowed-out portions of the same shape are staggered from each other in the horizontal direction.

7. The online detection system for the pressure resistance of liquid food packaging according to claim 6, characterized in that, The ratio of the diameter of the circular cutout to the maximum lateral length of the corresponding suction cup is (0.03-0.05):1; Within the same hollow section, the ratio of the width of the strip-shaped hollow to the diameter of the circular hollow is (0.6-0.8):1, and the ratio of the longitudinal length of the strip-shaped hollow to the diameter of the circular hollow is 1:

1.

8. The online detection system for the pressure resistance of liquid food packaging according to claim 2, characterized in that, The first track is a horizontal strip track and is located below the bag opener, allowing the two suction cups to move laterally below the bag opener.

9. The online detection system for the pressure resistance of liquid food packaging according to claim 2, characterized in that, The second track is perpendicular to the equipment wall and corresponds to the position of the bag opener, so that the clamping seat can be close to or far away from the bottom of the bag opener; The top of the heat-sealing part is equipped with a heat presser for heat-sealing the bottom of the packaged bag; the third track is parallel to the second track and is located between the second track and the equipment wall, so that the heat-sealing part can move back and forth under the packaged bag containing the finished product packaging box.

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