Method and device for defective sealing inspection

Abstract

The present invention relates to a method for defective sealing inspection. The method may comprise the steps of: obtaining an actual image of the appearance of a package which includes a sealing region and inside which a product is contained and sealed; obtaining positional information about the sealing region from the actual image; obtaining a thermal image, showing the temperature distribution of the sealing region, on the basis of the positional information about the sealing region; and determining whether sealing is defective by determining, on the basis of the thermal image, whether the sealing has been performed normally in the sealing region.

Description

Method and device for inspecting sealing defects

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2024-0053658, filed April 22, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present disclosure relates to a method and device for inspecting sealing defects.

[0004] Packaging is essential for safely delivering food products to consumers after manufacturing and processing. Packaging methods include the following: Food is contained in containers, pouches, and packaging films, and sealed to prevent contamination and spoilage. The most common sealing method is to heat-seal the top of the packaging material using heat and pressure.

[0005] At this time, if some of the food gets on the inner surface of the packaging material that is heat-sealed, or if the position or surface condition of the packaging material is poor, the heat-sealing will be poor, resulting in a poor seal.

[0006] Previously, inspectors visually inspected these defects. However, this method was problematic due to the potential for variation in inspection quality and human error, depending on the inspector's skill level and condition. In particular, visual inspection of defects involving foreign substances within the sealing area where heat is applied was nearly impossible. Therefore, inspection methods that involved pressing the product were necessary, resulting in lower productivity and a higher risk of dormant errors.

[0007] The present disclosure aims to provide a method and device for inspecting sealing defects in packaging by automating and efficiently performing the inspection.

[0008] A sealing defect inspection method according to one embodiment of the present disclosure may include the steps of: obtaining a visual image of the appearance of a package including a sealing area and having a product embedded therein and sealed; obtaining position information of the sealing area from the visual image; obtaining a thermal image representing a temperature distribution of the sealing area based on the position information of the sealing area; and determining a sealing defect by determining whether sealing is normally performed in the sealing area from the thermal image.

[0009] In one example, the method may further include a step of cooling the sealing area to promote a temperature decrease in the sealing area.

[0010] In one example, the step of promoting the temperature drop may be performed by blowing air into the sealing area.

[0011] In one example, the step of removing surface contamination of the packaging body may be further included.

[0012] In one example, the step of removing the surface contamination may be performed by blowing air over the packaging body.

[0013] In one example, the location information can be obtained by measuring coordinate values ​​and / or angle values ​​from a reference coordinate.

[0014] In one example, the method may further include a step of detecting surface contamination of the packaging body from the real-time image.

[0015] In one example, the step of detecting the surface contamination may be performed by comparison with real-world image information about the appearance of a reference uncontaminated packaging body.

[0016] In one example, the step of determining the sealing defect may determine the sealing defect if at least one area of ​​the sealing area has a temperature higher than a predetermined reference value compared to any other area.

[0017] A sealing defect inspection device according to one embodiment of the present disclosure may include a first image acquisition unit that obtains a real-time image of the appearance of a package including a sealing area and a product inside and sealed, and obtains positional information of an outline of the sealing area from the real-time image; a second image acquisition unit that obtains a thermal image representing a temperature distribution of the sealing area based on the positional information of the sealing area; and a sealing defect inspection unit that determines from the thermal image whether sealing is normally performed in the sealing area.

[0018] In one example, the sealing area may further include a cooling unit that cools the sealing area to promote a temperature drop in the sealing area.

[0019] In one example, the packaging body may further include a contamination removal unit for removing surface contamination.

[0020] In one example, the present invention may further include a contamination detection unit that detects surface contamination of the packaging body from the real-time image.

[0021] According to the present disclosure, the inspection of sealing defects in a packaging body can be automated and performed efficiently.

[0022] FIG. 1 is a drawing showing each step of a sealing defect inspection method according to one embodiment of the present disclosure.

[0023] Figure 2a is a drawing showing a packaging body.

[0024] Figure 2b is a drawing showing a thermal image of the packaging body.

[0025] Figure 2c is a drawing showing an inspection area in a thermal image of a package.

[0026] FIG. 3 is a drawing showing a sealing defect inspection device according to one embodiment of the present disclosure.

[0027] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings. Furthermore, when describing embodiments of the present disclosure, detailed descriptions of known components or functions will be omitted if they are deemed to hinder understanding of the embodiments of the present disclosure.

[0028] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present disclosure. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When a component is described as being "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but another component may also be "connected," "coupled," or "connected" between each component.

[0029] In this specification, the forward / backward, left / right, and up / down directions are referred to for convenience of explanation and may be orthogonal to each other. However, these directions are determined relatively, and the up / down direction does not necessarily imply a vertical direction.

[0030]

[0031] FIG. 1 is a drawing showing each step of a sealing defect inspection method according to one embodiment of the present disclosure.

[0032] Figure 2a is a drawing showing a packaging body.

[0033] Figure 2b is a drawing showing a thermal image of the packaging body.

[0034] Figure 2c is a drawing showing an inspection area in a thermal image of a package.

[0035] Referring to FIG. 1, a method for inspecting a sealing defect according to an embodiment of the present disclosure may include a step of obtaining a real-time image (S30), a step of obtaining location information of a sealing area (110) from the real-time image (S50), a step of obtaining a thermal image (S60), and a step of determining a sealing defect (S70). Each step is described in detail below.

[0036] Before the explanation, the packaging body (100) will be briefly described. Referring to FIG. 2a, the packaging body (100) refers to a state in which food or food products are placed inside a packaging material such as a container, pouch, or packaging film, and the sealing area (110) is fused and sealed. For example, the sealing area (110) may be heat-sealed. Foreign substances (120) caught between the sealing areas (110) are not visible from the outside and are therefore indicated by dotted lines. The shapes of the packaging body (100) and the sealing area (110) shown in the drawing, and the position of the sealing area (110) are merely examples and are not limited thereto.

[0037] In the step (S30) of obtaining a real-time image, a real-time image of the exterior of the package (100) in which the product is embedded and sealed can be obtained. For example, information regarding the exterior of the package (100) that can be confirmed with the naked eye can be obtained using a real-time camera. Specifically, if a foreign substance is present on the exterior of the package (100), if the sealing extends beyond the sealing area (110) and beyond the sealing area (110), etc. can be confirmed from the real-time image.

[0038] In the step (S50) of obtaining position information of the sealing area (110) from the real image, accurate position information of the sealing area (110) can be obtained from the real image. Referring to Fig. 2b, in the case of a thermal image, since the resolution is not high, the outline of the sealing area (110a) on the thermal image appears vague. On the other hand, in the case of a real image, since the resolution is high, the outline of the sealing area (110) appears clearly, so accurate position information of the sealing area (110) can be obtained.

[0039] Specifically, the position information of the sealing area (110) can be obtained by measuring coordinate values ​​and / or angle values ​​from the reference coordinates. For example, the reference coordinates can be set by specifying the X-axis and Y-axis based on the FOV (Field Of View) of the real-time camera, and the coordinates and / or angles of points forming the outer line of the sealing area (110) can be measured based on the reference coordinates. However, this method of obtaining position information is merely an example and is not limited thereto. In addition, not only the position information of the sealing area (110), but also the position information of the entire packaging body (100) can be obtained.

[0040] The location information of the sealing area (110) can be used to designate the corresponding area as an inspection area (130). In the inspection for sealing defects, there is no need to inspect the entire exterior of the package (100), and it is sufficient to inspect only the sealing area (110). Therefore, the efficiency of the inspection can be increased by designating the area corresponding to the sealing area (110) as an inspection area (130). At this time, the accuracy of designating the inspection area (130) can be increased by utilizing a real-world image with a clear outline of the sealing area (110).

[0041] In the step of obtaining a thermal image (S60), a thermal image (100a) of the package can be obtained. For example, a thermal imaging camera captures thermal energy radiated from the package (100) to obtain a thermal image (100a) of the package that represents the temperature distribution of the entire package (100). The thermal image is obtained for the entire package (100) as well as the sealing area (110), but the area that is the target of the sealing defect inspection is the sealing area (110). Therefore, by sending the location information of the sealing area (110) obtained from the real image, i.e., information on the inspection area (130), to the thermal image, it is possible to accurately determine where the sealing area (110), which is the area to be analyzed for the sealing defect inspection, is on the thermal image.

[0042] Referring to FIG. 2c, the sealing area (110a) on the thermal image has an unclear outline, but the inspection area (130) specified from the real image has accurate location information of the outline of the sealing area (110).

[0043] In the step (S70) of determining a sealing defect, the temperature distribution of the inspection area (130) on the thermal image can be analyzed to determine whether sealing is performed normally in the sealing area (110).

[0044] First, the principle of detecting a sealing defect by analyzing the temperature distribution will be briefly explained. When the sealing area (110) is heat-sealed to seal the package (100), the sealing area (110) radiates high-temperature thermal energy. The temperature of the sealing area (110) decreases over time, and when sealing is performed with a foreign substance (120) stuck in the sealing area (110), the temperature decrease in the area of ​​the sealing area (110) where the foreign substance (120) is stuck is slower than in other areas of the sealing area (110) where the foreign substance (120) is not stuck.

[0045] As a result, when a foreign substance (120) is stuck in the sealing area (110) and sealing is performed over time, the area where the foreign substance (120) is stuck exhibits a higher temperature than the area where the foreign substance (120) is not stuck. Using this principle, a sealing defect in which sealing is performed while a foreign substance (120) is stuck between the sealing areas (110) can be detected.

[0046] In the step (S70) of determining a sealing defect, the temperature distribution of the designated inspection area (130) is analyzed using the real-time image and location information. Referring to FIGS. 2b and 2c, the area where a foreign substance (120a) is present in the thermal image appears to have a higher temperature than the surrounding area, and the presence or absence of a sealing defect can be determined by analyzing the pattern of this temperature difference.

[0047] More specifically, if the area where the foreign substance (120a) is present in the thermal image has a temperature higher than the reference value compared to the surrounding area, it can be determined that there is a sealing defect. For example, in the case of a silver-coated pouch film package, the temperature of the sealing heating device that performs sealing can be set to about 200 degrees, and the average temperature of the sealing area (110) at the time of discharge after cooling can be about 65 to 70 degrees. At this point, if time passes and the average temperature of the sealing area (110) becomes about 25 degrees, the temperature of the area where the foreign substance (120a) is present can be about 36 degrees, in which case it can be determined that there is a sealing defect. However, the above figures are merely examples and are not limited thereto.

[0048] A method for detecting a sealing defect according to one embodiment of the present disclosure may further include a step (S10) of removing surface contamination of a packaging body, a step (S20) of promoting a temperature drop in a sealing area, and / or a step (S40) of detecting surface contamination of the packaging body from a real-world image. The execution order of each step (S10, S20, S30) is not limited to the order illustrated in FIG. 1, and the order may be changed, performed simultaneously, or omitted, and thus this is illustrated with a dotted line to indicate this. Hereinafter, each step will be described in detail.

[0049] In the step (S10) of removing surface contamination of the packaging body, contamination on the surface of the packaging body (100) can be removed. If contamination exists on the surface of the packaging body (100), there is a risk that a non-defective sealing can be mistaken for a defective sealing in the step (S70) of determining a defective sealing. For example, if contamination exists on the outer surface of the sealing area (110) rather than between the sealing areas (110), the temperature drop of the sealing area (110) can be slowed down by the contamination. Therefore, in the step (S70) of determining a defective sealing, contamination on the surface can be mistaken for a foreign substance being caught between the sealing areas (110). The step (S10) of removing surface contamination of the packaging body can prevent such a misunderstanding.

[0050] The step (S10) of removing surface contamination of the packaging body may be performed before, after, or simultaneously with the step (S30) of obtaining a visual image. Alternatively, it may be performed before or simultaneously with the step (S60) of obtaining a thermal image, but is not limited thereto. In addition, the step (S10) of removing surface contamination of the packaging body may be performed, for example, by a blower device that blows away foreign substances by sending wind.

[0051] The step (S20) of promoting a temperature drop in the sealing area can artificially cool the sealing area (110) to quickly detect a defective area where the temperature drops slowly. The step (S20) of promoting a temperature drop in the sealing area can be performed before, after, or simultaneously with the step (S30) of obtaining a visual image. Alternatively, it can be performed before the step (S60) of obtaining a thermal image, but is not limited thereto. This step can be performed by a blower device that blows wind to cool it. That is, the step (S10) of removing surface contamination of the packaging body and the step (S20) of promoting a temperature drop in the sealing area can be performed simultaneously by the blower cooling device.

[0052] In the step (S40) of detecting surface contamination of a package from a real-time image, surface contamination can be detected before detecting a sealing defect so as not to misdiagnose the sealing defect. The step (S40) of detecting surface contamination of a package from a real-time image can be performed between the step (S30) of obtaining a real-time image and the step (S60) of obtaining a thermal image. The step (S40) of detecting surface contamination of a package from a real-time image can be performed before, after, or simultaneously with the step (S50) of obtaining location information of a sealing area from a real-time image.

[0053] To detect surface contamination, real-world image information of the exterior of an uncontaminated package body is stored in advance as a reference. In the step of obtaining a real-world image (S30), the real-world image obtained is compared with the reference real-world image information. If there is a difference exceeding a certain level, it can be determined that the surface of the package body (100) is contaminated. If it is determined that the surface is contaminated, a step of obtaining a thermal image (S60) can be performed after the contamination is removed.

[0054] FIG. 3 is a drawing showing a sealing defect inspection device according to one embodiment of the present disclosure.

[0055] Referring to FIG. 3, a sealing defect inspection device (200) according to one embodiment of the present disclosure may include a first image acquisition unit (210), a second image acquisition unit (220), and a sealing defect inspection unit (230). Each component is described in detail below.

[0056] The first image acquisition unit (210) may perform the step (S30) of acquiring the above-described real-image image and the step (S50) of acquiring position information of the sealing area from the real-image image. For example, the first image acquisition unit (210) may have a real-image camera that acquires the real-image image, and may be equipped with a program that acquires position information of the package (100) and the sealing area (110) from the real-image image and designates the inspection area (130).

[0057] The second image acquisition unit (220) may perform the step (S60) of obtaining the thermal image described above. For example, the second image acquisition unit (220) may have a thermal imaging camera that obtains the thermal image.

[0058] The sealing defect inspection unit (230) may perform the step (S70) of determining the sealing defect described above. For example, a program may be built in that maps the location information of the sealing area obtained from the first image acquisition unit (210), i.e., the portion corresponding to the inspection area (130), to the thermal image obtained from the second image acquisition unit (220), and analyzes the pattern of the temperature distribution of the inspection area (130) to inspect for sealing defects.

[0059] Referring to FIG. 3, a sealing defect inspection device according to one embodiment of the present disclosure may further include a cooling unit (240), a contamination removal unit (250), and a contamination detection unit (260). Each component is described in detail below.

[0060] The cooling unit (240) can perform the step (S10) of promoting a temperature drop in the sealing area described above, and the contamination removal unit (250) can perform the step of removing surface contamination of the package described above. Referring to FIG. 3, the cooling unit (240) and the contamination removal unit (250) are shown as air-blowing cooling devices, so that cooling and contamination removal functions can be performed simultaneously by air-blowing. However, this is merely an example, and the shapes of the cooling unit (240) and the contamination removal unit (250) are not limited thereto.

[0061] The contamination detection unit (260) may perform a step (S40) of detecting surface contamination of the packaging body from the above-described real-world image. Referring to FIG. 3, the contamination detection unit (260) may be included in the first image acquisition unit (210), and may have a built-in program capable of detecting contamination from the real-world image obtained from the first image acquisition unit (210). However, this is merely an example, and the contamination detection unit (260) may be provided as a separate device from the first image acquisition unit (210).

[0062]

[0063] The above description is merely an example of the technical idea of ​​the present disclosure, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present disclosure. Therefore, the embodiments of the present disclosure are intended to illustrate rather than limit the technical idea of ​​the present disclosure, and the scope of the technical idea of ​​the present disclosure is not limited by these embodiments. The scope of protection of the present disclosure should be interpreted by the claims below, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of rights of the present disclosure.

Claims

1. A step of obtaining a real-time image of the appearance of a sealed package including a sealing area and a product embedded therein; A step of obtaining location information of the sealing area from the above real-time image; A step of obtaining a thermal image representing the temperature distribution of the sealing area based on the location information of the sealing area; and A sealing defect inspection method comprising a step of determining a sealing defect by determining whether sealing is normally performed in the sealing area from the thermal image.

2. In claim 1, A method for inspecting a sealing defect, further comprising a step of cooling the sealing area to promote a temperature drop in the sealing area.

3. In claim 2, A method for inspecting a sealing defect, wherein the step of promoting the temperature drop is performed by blowing air to the sealing area.

4. In claim 1, A method for inspecting sealing defects further comprising a step of removing surface contamination of the above packaging body.

5. In claim 4, A method for inspecting a sealing defect, wherein the step of removing the surface contamination is performed by blowing air to the packaging body.

6. In claim 1, A sealing defect inspection method in which the above location information is obtained by measuring coordinate values ​​and / or angle values ​​from a reference coordinate.

7. In claim 1, A sealing defect inspection method further comprising a step of detecting surface contamination of the packaging body from the above-mentioned real-world image.

8. In claim 7, A sealing defect inspection method in which the step of detecting the above surface contamination is performed by comparison with actual image information on the appearance of a reference uncontaminated packaging body.

9. In claim 1, The steps for determining the above sealing defect are: A sealing defect inspection method that determines a sealing defect when at least one area among the above sealing areas has a temperature higher than a standard value compared to any other area.

10. A first image acquisition unit that obtains a real-time image of the appearance of a sealed package including a sealing area and a product therein, and obtains location information of the sealing area from the real-time image; A second image acquisition unit that obtains a thermal image representing the temperature distribution of the sealing area based on the position information of the outer line of the sealing area; A sealing defect inspection device including a sealing defect inspection unit that determines whether sealing is normally performed in the sealing area from the thermal image.

11. In claim 10, A sealing defect inspection device further comprising a cooling unit that cools the sealing area to promote a temperature drop in the sealing area.

12. In claim 10, A sealing defect inspection device further comprising a contamination removal unit for removing surface contamination of the above packaging body.

13. In claim 10, A sealing defect inspection device further comprising a contamination detection unit that detects surface contamination of the packaging body from the above-mentioned real-world image.

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