Food packaging bag air tightness detection device and detection method thereof

Abstract

The invention belongs to the technical field of food production, and relates to a food packaging bag air tightness detection device. The invention further relates to a detection method of the food packaging bag air tightness detection device. One end of a first pipeline (1) is communicated with an air source (2), the other end of the first pipeline (1) is communicated with an inlet of a flow selection valve (3), an outlet of the flow selection valve (3) is communicated with one end of a second pipeline (4), the other end of the second pipeline (4) is communicated with a packaging bag detection component (5), the flow selection valve (3) is communicated with one end of a third pipeline (6), and the other end of the third pipeline (6) is communicated with an exhaust valve (7). A pressure sensor (8) is arranged at the position, close to the packaging bag detection component (5), of the second pipeline (4). According to the food packaging bag air tightness detection device, on the basis of the positive pressure detection technology, tiny leakage points can be precisely detected, packaging bag air tightness detection can be completed, the leakage speed is detected, the air pressure of the air tightness detection environment is prevented from being influenced by the altitude, the detection sensitivity is improved, and the application range is widened.

Description

Technical Field

[0001] The present invention belongs to the technical field of food production, and more specifically, relates to a device for detecting air tightness of food packaging bags. The present invention also relates to a detection method for the device for detecting air tightness of food packaging bags. Background Art

[0002] The two most common airtightness testing methods are negative pressure and positive pressure. The principle of negative pressure testing is generally to create an environment within 90kPa lower than the ambient atmospheric pressure, and observe the bubbles when the package leaks in water. Positive pressure testing is usually used for rigid containers with high sealing properties.

[0003] At present, there are two main instruments for measuring the air tightness of food packaging (soft packaging materials, hard containers) in the laboratory: 1. Positive pressure detection: insert the hollow needle on the detection instrument into the package and place the package in water. Pressurize the package to be tested through the needle and observe the bubbles coming out of the seal of the package to detect the air tightness. Although this method can be used for most hard containers, it has the following defects: a. For some foods that are extremely sensitive to air leakage, when there is a very small air leak in the hard container, the conventional method of applying positive pressure to observe bubbles in water cannot observe the bubbles in a short time, resulting in the release of unqualified packages. B. For some dry solid foods, when the air tightness requirements of the hard container are not absolutely strict, that is, extremely small air leaks are allowed but not small air leaks, what kind of air leak is acceptable cannot be judged by conventional positive pressure detection, and a quantitative method is needed to evaluate the degree of air leak. 2. Negative pressure detection: The principle is to place the package in the cavity of the instrument and immerse it in water. The cavity is vacuumed to form an environment within 90kPa lower than the ambient pressure, and bubbles are observed in the package to find the leak point. However, this method has the following defects:

[0004] a. For soft packaging with a relatively flat shape, the capacity of conventional small air compressors is limited, and the packaging cannot be fully inflated. It can only be partially inflated, which reduces the air pressure inside the packaging. Therefore, even if there is a tiny leak, the leak cannot be detected. b. For food produced at low altitudes, the leak is more obvious when sold at high altitudes. However, in food workshops at low altitudes, due to the high ambient air pressure, the air compressor equipped with the air tightness testing instrument has a weak ability to form negative pressure and cannot effectively detect extremely small leaks. c. For packaging that is itself under negative pressure, it is also difficult to effectively detect leaks. d. For rigid containers with extremely high air tightness requirements, the low negative pressure of the instrument is not enough to effectively measure the reliability of air tightness.

[0005] In the prior art, there is a technology named "A Plastic Packaging Bag Sealing Air Tightness Detection Device" and with a publication (announcement) number of "CN114878109B", which includes a shell, a top shell, a movable component, a lifting plate, a pressure detector, a fixed shell, a packaging bag and a fixed component, wherein the top shell is arranged on the top inside the shell, the movable component is arranged on the top shell, the lifting plate is slidably arranged inside the shell, the lifting plate is slidably arranged inside the shell, the pressure detector is arranged on the lifting plate, the fixed shell is arranged on the bottom inside the shell, the packaging bag is arranged on the top of the fixed shell, and the fixed component is arranged inside the fixed shell; the present invention belongs to the field of air tightness detection technology, specifically refers to a plastic packaging bag sealing air tightness detection device which can drive the pressure detector to move by a movable component to make the detection flexible, detect the pressure inside the packaging bag by the pressure detector when squeezing the packaging bag to prevent the packaging bag from leaking and entering water droplets, and fix the packaging bag by the fixed component to prevent the packaging bag from sliding.

[0006] However, this technology does not involve the technical problems and technical solutions of the present application. Summary of the invention

[0007] The technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a food packaging bag air tightness detection device is provided which has a simple structure and can accurately detect tiny leaks in positive pressure detection technology, complete air tightness detection of packaging bags, and detect leakage rate, while avoiding the influence of altitude on the air tightness detection environment pressure, thereby improving detection sensitivity and scope of application.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is:

[0009] The present invention is a device for detecting air tightness of food packaging bags, wherein one end of a first pipeline is connected to an air source, the other end of the first pipeline is connected to an inlet of a flow selection valve, the outlet of the flow selection valve is connected to one end of a second pipeline, the other end of the second pipeline is connected to a packaging bag detection component, the flow selection valve is simultaneously connected to one end of a third pipeline, the other end of the third pipeline is connected to an exhaust valve, and a pressure sensor is arranged on the second pipeline near the packaging bag detection component;

[0010] After the airflow enters the packaging bag to be tested, the pressure sensor detects and obtains the actual pressure value inside the packaging bag to be tested. The input airflow flows out from the exhaust valve at the same time. When the actual pressure value of the packaging bag to be tested obtained by the pressure sensor is stable, it indicates that the packaging bag to be tested has good air tightness;

[0011] When the actual pressure value of the detected packaging bag obtained by the pressure sensor is lower than the set pressure value, it indicates that there is a leak in the detected packaging bag. The greater the difference between the actual pressure value of the detected packaging bag obtained by the pressure sensor and the set pressure value, the more serious the leak in the detected packaging bag is.

[0012] A flow sensor is arranged near the flow selection valve in the first pipeline, and the pressure sensor 8 and the flow sensor are connected to the display component respectively.

[0013] A pre-pressure regulating valve and a final pressure regulating valve are arranged on the first pipeline; the pre-pressure regulating valve is close to the gas source, and the final pressure regulating valve is close to the pre-pressure regulating valve.

[0014] The flow selector valve, the pre-pressure regulating valve and the final pressure regulating valve are all electronic valves, and the flow selector valve, the pre-pressure regulating valve and the final pressure regulating valve are respectively connected to control components.

[0015] The packaging bag detection component comprises a detection component body, the rear of which is connected to the second pipeline, the upper part of the detection component body is an upward convex upper arc surface, and the lower part of the detection component body is a downward convex lower arc surface.

[0016] The detection component body between the upper arc surface and the lower arc surface is provided with a long air outlet groove, and the opening of the detected packaging bag is provided with a structure that can be fitted onto the detection component body from the front of the detection component body.

[0017] The rear part of the detection component body is connected to the fixed bracket, an upper pressure cylinder is arranged above the detection component body, an upper pressure component with an upper arc-shaped pressure surface with an upward concave is arranged at the lower end of the upper pressure cylinder, a lower pressure cylinder is arranged below the detection component body, a lower pressure component with a lower arc-shaped pressure surface with an upward concave is arranged at the upper end of the lower pressure cylinder, and the upper pressure cylinder and the lower pressure cylinder are respectively connected to the control component.

[0018] The upper clamping component and the lower clamping component are both structures made of rubber material, and the detection component body and the air outlet slot are structures made of hard material; the upper arc-shaped clamping surface of the upper clamping component and the upper arc-shaped surface of the detection component body have the same radius size, and the lower arc-shaped clamping surface of the lower clamping component and the lower arc-shaped surface of the detection component body have the same radius size; each side of the upper arc-shaped clamping surface of the upper clamping component is provided with an upper side linear extension edge, and each side of the lower arc-shaped clamping surface of the lower clamping component is provided with a lower side linear extension edge.

[0019] The present invention also relates to a detection method for a food packaging bag air tightness detection device, which has simple steps and can accurately detect tiny leaks in positive pressure detection technology, complete air tightness detection of packaging bags, and detect leakage speed, while avoiding the influence of altitude on the air tightness detection environment pressure, and improving detection sensitivity and application scope. The detection steps of the detection method for the food packaging bag air tightness detection device are as follows:

[0020] S1: Connect the opening of the packaging bag to be inspected to the packaging bag inspection component, and fix the packaging bag to be inspected and the packaging bag inspection component;

[0021] S2: Start the gas source to supply air flow, and the control component controls the flow selection valve to adjust the air flow passing through the flow selection valve 2 to the set pressure;

[0022] S3: After the airflow enters the packaging bag to be tested, the pressure sensor detects and obtains the actual pressure value inside the packaging bag to be tested, and the input airflow flows out from the exhaust valve at the same time. When the actual pressure value of the packaging bag to be tested obtained by the pressure sensor is stable, it indicates that the packaging bag to be tested has good air tightness;

[0023] S4: When the actual pressure value of the detected packaging bag obtained by the pressure sensor is lower than the set pressure value, it indicates that the detected packaging bag has a leak. The larger the difference between the actual pressure value of the detected packaging bag obtained by the pressure sensor and the set pressure value is, the more serious the leak is.

[0024] When the opening of the inspected packaging bag is connected to the packaging bag detection component, the opening of the inspected packaging bag is first put onto the detection component body from the front of the detection component body of the packaging bag detection component, and then the upper pressing component of the upper pressure cylinder and the lower pressing component of the lower pressure cylinder are controlled by the control component to respectively press against the inspected packaging bag to achieve sealing between the inspected packaging bag and the packaging bag detection component.

[0025] The technical solution of the present invention is adopted, and the working principle and beneficial effects are as follows:

[0026] The food packaging bag air tightness detection device described in the present invention has one end of the first pipeline connected to the air source, and the air pressure source is used to supply an airflow that meets the positive pressure requirement. The other end of the first pipeline 1 is connected to the inlet of the flow selection valve, and the flow selection valve 3 is used to adjust the pressure of the airflow passing through, so that the airflow load from the flow selection valve to the packaging bag meets the specific requirements. For example, for detection points with low altitudes, the air flow rate can be increased. For flat soft packaging or packaging that is itself under negative pressure, the flow and pressure of the positive pressure airflow can also be increased to improve the reliability of air tightness detection. The outlet of the flow selection valve is connected to one end of the second pipeline, and the other end of the second pipeline is connected to the packaging bag detection component. The packaging bag to be detected is reliably connected to the packaging bag detection component to ensure the sealing of the two after connection, so as to ensure the accuracy of the detection result. The flow selection valve is connected to one end of the third pipeline at the same time, and the other end of the third pipeline is connected to the exhaust valve. While conveying the airflow, the exhaust valve exhausts the airflow. A pressure sensor is arranged on the second pipeline near the packaging bag detection component; the pressure sensor is used to obtain the test pressure value, that is, after the airflow enters the packaging bag to be detected, the pressure sensor detects and obtains the actual pressure value inside the packaging bag to be detected, and the input airflow flows out from the exhaust valve at the same time. When performing air tightness detection, the sealing is judged according to the difference in the actual pressure value fed back by the pressure sensor. When the actual pressure value of the packaging bag to be detected obtained by the pressure sensor is stable, it indicates that the air tightness of the packaging bag to be detected is good; when the actual pressure value of the packaging bag to be detected obtained by the pressure sensor is lower than the set pressure value, it indicates that there is air leakage in the packaging bag to be detected. The greater the difference between the actual pressure value of the packaging bag to be detected obtained by the pressure sensor and the set pressure value, the more serious the leakage of the packaging bag to be detected. The device of the present invention can use a compressed airflow with low pressure as the air source for air tightness detection, and continuously apply positive pressure to the inside of the packaging bag to be detected by adjusting the stability of the output airflow pressure. When the packaging bag to be detected leaks, the airflow pressure will decay. The pressure sensor can quantitatively measure the actual value of the air pressure in the tested packaging bag and the size of the pressure decay, so as to not only determine whether there is a leak, but also quantitatively analyze the extent of the leak in the tested packaging bag, which is suitable for extremely small leak points. The size of the positive pressure applied to the tested packaging bag can be adjusted by the flow selector valve, which is especially suitable for flat soft packaging bags to be tested, ensuring that the tested packaging bag is fully inflated, and the detection is fast and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The following is a brief description of the contents and symbols in the drawings of this specification:

[0028] Figure 1 It is a structural schematic diagram of the air tightness detection device for food packaging bags according to the present invention;

[0029] Figure 2It is a structural schematic diagram of a packaging bag detection component of the food packaging bag air tightness detection device of the present invention;

[0030] The marks in the attached drawings are respectively: 1. first pipeline; 2. air source (positive pressure air source); 3. flow selection valve; 4. second pipeline; 5. packaging bag detection component; 6. third pipeline; 7. exhaust valve; 8. pressure sensor; 9. flow sensor; 10. pre-pressure regulating valve; 11. final pressure regulating valve; 12. detection component body; 13. upper arc surface; 14. lower arc surface; 15. air outlet long groove; 16. detected packaging bag; 17. upper pressure cylinder; 18. upper arc-shaped pressing surface; 19. upper pressing component; 20. lower pressure cylinder; 21. lower arc-shaped pressing surface; 22. lower pressing component; 23. straight line extension edge of upper side surface; 24. straight line extension edge of lower side surface. DETAILED DESCRIPTION

[0031] The following is a further detailed description of the specific implementation of the present invention, such as the shape, structure, mutual position and connection relationship between the various components involved, the function and working principle of each part, etc., through the description of the embodiments with reference to the accompanying drawings:

[0032] As attached Figure 1 , Attachment Figure 2As shown, the present invention is a food packaging bag air tightness detection device, one end of the first pipeline 1 is connected to the air source 2, the other end of the first pipeline 1 is connected to the inlet of the flow selection valve 3, the outlet of the flow selection valve 3 is connected to one end of the second pipeline 4, the other end of the second pipeline 4 is connected to the packaging bag detection component 5, the flow selection valve 3 is simultaneously connected to one end of the third pipeline 6, the other end of the third pipeline 6 is connected to the exhaust valve 7, and a pressure sensor 8 is arranged on the second pipeline 4 near the packaging bag detection component 5; after the airflow enters the detected packaging bag 16, the pressure sensor 8 detects and obtains the actual pressure value inside the detected packaging bag 16, and the input airflow flows out from the exhaust valve 7 at the same time. When the actual pressure value of the detected packaging bag 16 detected by the pressure sensor 8 is stable, it indicates that the detected packaging bag 16 has good air tightness; when the actual pressure value of the detected packaging bag 16 detected by the pressure sensor 8 is lower than the set pressure value, it indicates that the detected packaging bag 16 has air leakage, and the greater the difference between the actual pressure value of the detected packaging bag 16 detected by the pressure sensor 8 and the set pressure value, the more serious the air leakage of the detected packaging bag 16 is. The above structure proposes an improved technical solution to address the deficiencies in the prior art. When the structure is set, one end of the first pipeline 1 is connected to the air source 2, and the air pressure source 2 is used to supply an airflow that meets the positive pressure requirements. The other end of the first pipeline 1 is connected to the inlet of the flow selection valve 3, and the flow selection valve 3 is used to adjust the pressure of the passing airflow so that the airflow load of the flow selection valve to the packaging bag meets the specific requirements. For example, for detection points with low altitudes, the airflow flow rate can be increased. For flat soft packaging or packaging that is itself under negative pressure, the flow and pressure of the positive pressure airflow can also be increased to improve the reliability of airtightness detection. The outlet of the flow selection valve 3 is connected to one end of the second pipeline 4, and the other end of the second pipeline 4 is connected to the packaging bag detection component 5. The packaging bag 16 to be detected is reliably connected to the packaging bag detection component to ensure the sealing of the two after connection, so as to ensure the accuracy of the detection results. The flow selector valve 3 is connected to one end of the third pipeline 6 at the same time, and the other end of the third pipeline 6 is connected to the exhaust valve 7. While conveying the airflow, the exhaust valve 7 exhausts the airflow. A pressure sensor 8 is arranged on the second pipeline 4 near the packaging bag detection component 5; the pressure sensor 8 is used to obtain the test pressure value, that is, after the airflow enters the packaging bag 16 to be detected, the pressure sensor 8 detects and obtains the actual pressure value inside the packaging bag 16 to be detected, and the input airflow flows out from the exhaust valve 7 at the same time. When the air tightness test is performed, the sealing is judged according to the difference in the actual pressure value fed back by the pressure sensor 8. When the actual pressure value of the packaging bag 16 to be detected obtained by the pressure sensor 8 is stable, it indicates that the packaging bag 16 to be detected has good air tightness; when the actual pressure value of the packaging bag 16 to be detected obtained by the pressure sensor 8 is lower than the set pressure value, it indicates that the packaging bag 16 to be detected has air leakage, and the greater the difference between the actual pressure value of the packaging bag 16 to be detected obtained by the pressure sensor 8 and the set pressure value, the more serious the air leakage of the packaging bag 16 to be detected.The device of the present invention can perform airtightness detection by using a compressed airflow with low pressure as the air source 2, and continuously apply positive pressure to the inside of the packaging bag 16 to be detected by adjusting the stability of the output airflow pressure. When the packaging bag 16 to be detected leaks, the airflow pressure will decay. The pressure sensor 8 can quantitatively measure the actual value of the air pressure in the packaging bag 16 to be detected and the magnitude of the pressure decay, so that it can not only determine whether there is a leak, but also quantitatively analyze the degree of leak in the packaging bag 16 to be detected, which is suitable for extremely small leaks. The magnitude of the positive pressure applied to the packaging bag 16 to be detected can be adjusted by the flow selection valve 3, which is particularly suitable for flat soft packaging bags 16 to be detected, ensuring that the packaging bag 16 to be detected is fully inflated, and the detection is fast and reliable. The food packaging bag airtightness detection device of the present invention has a simple structure, and in terms of positive pressure detection technology, it can accurately detect tiny leaks, complete the packaging bag airtightness detection, and detect the leakage speed, while avoiding the air pressure of the airtightness detection environment being affected by the altitude, thereby improving the detection sensitivity and scope of application.

[0033] The first pipeline 1 is provided with a flow sensor 9 near the flow selector valve 3, and the pressure sensor 8 and the flow sensor 9 are connected to the display component respectively. In the above structure, the real-time pressure values ​​obtained by the pressure sensor 8 and the flow sensor 9 are displayed on the display component, which is convenient for intuitive viewing. On-site personnel judge the sealing performance according to the value size and attenuation condition.

[0034] The first pipeline 1 is provided with a pre-pressure regulating valve 10 and a final pressure regulating valve 11; the pre-pressure regulating valve 10 is close to the gas source 2, and the final pressure regulating valve 11 is close to the pre-pressure regulating valve 10. In the above structure, the gas source 2 outputs a positive pressure gas flow, and through the regulation of the pre-pressure regulating valve 10 and the final pressure regulating valve 11, a stable and measurable gas flow pressure can be output from the first pipeline 1 to the direction of the flow selector valve 3.

[0035] The flow selector valve 3, the pre-pressure regulating valve 10 and the final pressure regulating valve 11 are all electronic valves, and the flow selector valve 3, the pre-pressure regulating valve 10 and the final pressure regulating valve 11 are respectively connected to the control components. With the above structure, the flow selector valve 3, the pre-pressure regulating valve 10 and the final pressure regulating valve 11 can realize automatic adjustment.

[0036] The packaging bag detection component 5 includes a detection component body 12, the rear part of the detection component body 12 is connected to the second pipeline 4, the upper part of the detection component body 12 is an upper convex arc surface 13, and the lower part of the detection component body 12 is a lower convex arc surface 14. The detection component body 12 between the upper arc surface 13 and the lower arc surface 14 is provided with a long air outlet groove 15, and the opening of the detected packaging bag 16 is provided with a structure that can be fitted onto the detection component body 12 from the front of the detection component body 12. The rear part of the detection component body 12 is connected to a fixed bracket, an upper pressure cylinder 17 is provided above the detection component body 12, and an upper pressing component 19 with an upper concave upper arc pressing surface 18 is provided at the lower end of the upper pressure cylinder 17, and a lower pressure cylinder 20 is provided below the detection component body 12, and a lower pressure component 22 with an upper concave lower arc pressing surface 21 is provided at the upper end of the lower pressure cylinder 20, and the upper pressure cylinder 17 and the lower pressure cylinder 20 are respectively connected to the control component. In the above structure, after the opening of the inspected packaging bag 16 is inserted into the inspection component body 12 from the front of the inspection component body 12, the control component controls the upper pressing component 19 of the upper pressing cylinder 17 and the lower pressing component 22 of the lower pressing cylinder 20 to respectively press against the inspected packaging bag 16, thereby achieving sealing between the inspected packaging bag 16 and the packaging bag inspection component 5, thereby ensuring that the inspection result is not affected.

[0037] The upper clamping component 19 and the lower clamping component 22 are both made of rubber materials, and the detection component body 12 and the long air outlet slot 15 are made of hard materials; the upper arc-shaped clamping surface 18 of the upper clamping component 19 and the upper arc-shaped surface 13 of the detection component body 12 have the same radius size, and the lower arc-shaped clamping surface 21 of the lower clamping component 22 and the lower arc-shaped surface 14 of the detection component body 12 have the same radius size; each side of the upper arc-shaped clamping surface 18 of the upper clamping component 19 is provided with an upper side straight extension edge 23, and each side of the lower arc-shaped clamping surface 21 of the lower clamping component 22 is provided with a lower side straight extension edge 24. In the above structure, the upper clamping component 19 and the lower clamping component 22 are both made of rubber materials, and they are deformed after being pressed against the detection component body 12, ensuring that the joint parts are reliably fitted and sealed, avoiding air leakage at the joint part of the detection component body 12 and the detected packaging bag 16, so as not to affect the accuracy of the detection result.

[0038] The present invention also relates to a detection method for a food packaging bag air tightness detection device, which has simple steps and can accurately detect tiny leaks in positive pressure detection technology, complete air tightness detection of packaging bags, and detect leakage speed, while avoiding the influence of altitude on the air tightness detection environment pressure, and improving detection sensitivity and application scope. The detection steps of the detection method for the food packaging bag air tightness detection device are as follows:

[0039] S1: Connect the opening of the packaging bag 16 to be inspected to the packaging bag inspection component 5, and fix the packaging bag 16 to be inspected and the packaging bag inspection component 5;

[0040] S2: Start the gas source to supply the air flow, and the control component controls the flow selection valve 2 to adjust the air flow passing through the flow selection valve 2 to the set pressure;

[0041] S3: After the airflow enters the packaging bag 16 to be inspected, the pressure sensor 8 detects and obtains the actual pressure value inside the packaging bag 16 to be inspected, and the input airflow flows out from the exhaust valve 7 at the same time. When the actual pressure value of the packaging bag 16 to be inspected obtained by the pressure sensor 8 is stable, it indicates that the packaging bag 16 to be inspected has good air tightness;

[0042] S4: When the actual pressure value of the detected packaging bag 16 detected by the pressure sensor 8 is lower than the set pressure value, it indicates that there is air leakage in the detected packaging bag 16. The larger the difference between the actual pressure value of the detected packaging bag 16 detected by the pressure sensor 8 and the set pressure value is, the more serious the air leakage of the detected packaging bag 16 is.

[0043] When the opening of the inspected packaging bag 16 is connected to the packaging bag detection component 5, the opening of the inspected packaging bag 16 is first inserted into the detection component body 12 from the front of the detection component body 12 of the packaging bag detection component 5, and then the upper pressing component 19 of the upper pressing cylinder 17 and the lower pressing component 22 of the lower pressing cylinder 20 are controlled by the control component to respectively press against the inspected packaging bag 16, so as to achieve the sealing between the inspected packaging bag 16 and the packaging bag detection component 5.

[0044] The food packaging bag air tightness detection device described in the present invention has a first pipeline 1, one end of which is connected to an air source 2, and the air pressure source 2 is used to supply an airflow that meets the positive pressure requirement. The other end of the first pipeline 1 is connected to the inlet of a flow selection valve 3, and the flow selection valve 3 is used to adjust the pressure of the airflow passing through, so that the airflow load of the flow selection valve to the packaging bag meets the specific requirements. For example, for detection points with low altitudes, the airflow rate can be increased. For flat soft packaging or packaging that is itself under negative pressure, the flow and pressure of the positive pressure airflow can also be increased to improve the reliability of air tightness detection. The outlet of the flow selection valve 3 is connected to one end of the second pipeline 4, and the other end of the second pipeline 4 is connected to the packaging bag detection component 5. The packaging bag 16 to be detected is reliably connected to the packaging bag detection component to ensure the sealing of the two after connection, so as to ensure the accuracy of the detection result. The flow selector valve 3 is connected to one end of the third pipeline 6 at the same time, and the other end of the third pipeline 6 is connected to the exhaust valve 7. While conveying the airflow, the exhaust valve 7 exhausts the airflow. A pressure sensor 8 is arranged on the second pipeline 4 near the packaging bag detection component 5; the pressure sensor 8 is used to obtain the test pressure value, that is, after the airflow enters the packaging bag 16 to be detected, the pressure sensor 8 detects and obtains the actual pressure value inside the packaging bag 16 to be detected, and the input airflow flows out from the exhaust valve 7 at the same time. When the air tightness test is performed, the sealing is judged according to the difference in the actual pressure value fed back by the pressure sensor 8. When the actual pressure value of the packaging bag 16 to be detected obtained by the pressure sensor 8 is stable, it indicates that the packaging bag 16 to be detected has good air tightness; when the actual pressure value of the packaging bag 16 to be detected obtained by the pressure sensor 8 is lower than the set pressure value, it indicates that the packaging bag 16 to be detected has air leakage, and the greater the difference between the actual pressure value of the packaging bag 16 to be detected obtained by the pressure sensor 8 and the set pressure value, the more serious the air leakage of the packaging bag 16 to be detected. The device of the present invention can perform air-tightness detection by using a compressed air flow with low pressure as the air source 2, and continuously apply positive pressure to the inside of the packaging bag 16 to be detected by adjusting the stability of the output air flow pressure. When the packaging bag 16 to be detected leaks, the air flow pressure will decay. The pressure sensor 8 can quantitatively measure the actual value of the air pressure inside the packaging bag 16 to be detected and the magnitude of the pressure decay, so that it can not only determine whether there is a leak, but also quantitatively analyze the degree of leak in the packaging bag 16 to be detected, which is suitable for extremely small leak points. The magnitude of the positive pressure applied to the packaging bag 16 to be detected can be adjusted by the flow selection valve 3, which is particularly suitable for flat soft packaging bags 16 to be detected, ensuring that the packaging bag 16 to be detected is fully inflated, and the detection is quick and reliable.

[0045] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A food packaging bag air tightness detection device, characterized in that: One end of the first pipeline (1) is connected to the gas source (2), the other end of the first pipeline (1) is connected to the inlet of the flow selection valve (3), the outlet of the flow selection valve (3) is connected to one end of the second pipeline (4), the other end of the second pipeline (4) is connected to the packaging bag detection component (5), the flow selection valve (3) is simultaneously connected to one end of the third pipeline (6), the other end of the third pipeline (6) is connected to the exhaust valve (7), and a pressure sensor (8) is provided on the second pipeline (4) near the packaging bag detection component (5); After the airflow enters the packaging bag (16) to be inspected, the pressure sensor (8) detects and obtains the actual pressure value inside the packaging bag (16) to be inspected, and the input airflow flows out from the exhaust valve (7) at the same time. When the actual pressure value of the packaging bag (16) to be inspected obtained by the pressure sensor (8) is stable, it indicates that the packaging bag (16) to be inspected has good air tightness; When the actual pressure value of the detected packaging bag (16) detected by the pressure sensor (8) is lower than the set pressure value, it indicates that the detected packaging bag (16) has air leakage. The greater the difference between the actual pressure value of the detected packaging bag (16) detected by the pressure sensor (8) and the set pressure value, the more serious the air leakage of the detected packaging bag (16) is.

2. The food packaging bag air tightness detection device according to claim 1, characterized in that: A flow sensor (9) is arranged on the first pipeline (1) near the flow selection valve (3), and the pressure sensor (8) and the flow sensor (9) are respectively connected to a display component.

3. The food packaging bag air tightness detection device according to claim 1 or 2, characterized in that: A pre-pressure regulating valve (10) and a final pressure regulating valve (11) are arranged on the first pipeline (1); the pre-pressure regulating valve (10) is close to the gas source (2), and the final pressure regulating valve (11) is close to the pre-pressure regulating valve (10).

4. The food packaging bag air tightness detection device according to claim 3, characterized in that: The flow selector valve (3), the pre-pressure regulating valve (10) and the final pressure regulating valve (11) are all electronic valves, and the flow selector valve (3), the pre-pressure regulating valve (10) and the final pressure regulating valve (11) are respectively connected to the control components.

5. The food packaging bag air tightness detection device according to claim 1 or 2, characterized in that: The packaging bag detection component (5) comprises a detection component body (12), the rear portion of the detection component body (12) is connected to the second pipeline (4), the upper portion of the detection component body (12) is an upwardly convex upper arc surface (13), and the lower portion of the detection component body (12) is a downwardly convex lower arc surface (14).

6. The device for detecting air tightness of food packaging bags according to claim 5, characterized in that: The detection component body (12) between the upper arc surface (13) and the lower arc surface (14) is provided with a long air outlet groove (15), and the opening of the detected packaging bag (16) is provided with a structure capable of being fitted onto the detection component body (12) from the front of the detection component body (12).

7. The device for detecting air tightness of food packaging bags according to claim 6, characterized in that: The rear part of the detection component body (12) is connected to a fixed bracket, an upper pressure cylinder (17) is arranged above the detection component body (12), an upper pressure component (19) with an upper concave arc-shaped pressure surface (18) is arranged at the lower end of the upper pressure cylinder (17), a lower pressure cylinder (20) is arranged below the detection component body (12), a lower pressure component (22) with an upper concave arc-shaped pressure surface (21) is arranged at the upper end of the lower pressure cylinder (20), and the upper pressure cylinder (17) and the lower pressure cylinder (20) are respectively connected to the control component.

8. The device for detecting air tightness of food packaging bags according to claim 7, characterized in that: The upper clamping component (19) and the lower clamping component (22) are both structures made of rubber material, and the detection component body (12) and the air outlet slot (15) are structures made of hard material; the upper arc-shaped clamping surface (18) of the upper clamping component (19) and the upper arc-shaped surface (13) of the detection component body (12) have the same radius size, and the lower arc-shaped clamping surface (21) of the lower clamping component (22) and the lower arc-shaped surface (14) of the detection component body (12) have the same radius size; each side of the upper arc-shaped clamping surface (18) of the upper clamping component (19) is respectively provided with an upper side straight extension edge (23), and each side of the lower arc-shaped clamping surface (21) of the lower clamping component (22) is respectively provided with a lower side straight extension edge (24).

9. A method for detecting air tightness of food packaging bags, characterized in that: The detection steps of the detection method of the food packaging bag air tightness detection device are as follows: S1: Connecting the opening of the packaging bag (16) to be inspected to the packaging bag inspection component (5), and fixing the packaging bag (16) to be inspected and the packaging bag inspection component (5); S2: The air source is started to supply air flow, and the control component controls the flow selection valve (2) to adjust the air flow passing through the flow selection valve (2) to a set pressure; S3: After the airflow enters the packaging bag (16) to be inspected, the pressure sensor (8) detects and obtains the actual pressure value inside the packaging bag (16) to be inspected, and the input airflow flows out from the exhaust valve (7) at the same time. When the actual pressure value of the packaging bag (16) to be inspected obtained by the pressure sensor (8) is stable, it indicates that the packaging bag (16) to be inspected has good air tightness; S4: When the actual pressure value of the detected packaging bag (16) detected by the pressure sensor (8) is lower than the set pressure value, it indicates that the detected packaging bag (16) has air leakage. The greater the difference between the actual pressure value of the detected packaging bag (16) detected by the pressure sensor (8) and the set pressure value, the more serious the air leakage of the detected packaging bag (16) is.

10. The detection method of the food packaging bag air tightness detection device according to claim 9, characterized in that: When the opening of the packaging bag (16) to be inspected is connected to the packaging bag inspection component (5), the opening of the packaging bag (16) to be inspected is first inserted into the inspection component body (12) from the front of the inspection component body (12) of the packaging bag inspection component (5), and then the upper pressing component (19) of the upper pressing cylinder (17) and the lower pressing component (22) of the lower pressing cylinder (20) are controlled by the control component to respectively press against the packaging bag (16) to be inspected, thereby achieving sealing between the packaging bag (16) to be inspected and the packaging bag inspection component (5).

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