JP6432181B2 - LAMINATE INSPECTING METHOD, LAMINATE MANUFACTURING METHOD, AND LAMINATE INSPECTING DEVICE - Google Patents

Description

  The present invention relates to an inspection method for inspecting whether or not an adhesive is provided between a first layer and a second layer in a laminate including a first layer and a second layer. The present invention also relates to a laminate manufacturing method and a laminate inspection apparatus.

  As a method for nondestructively inspecting the presence or absence of product defects, a method using electromagnetic waves such as X-rays is known. For example, in Patent Document 1, there is a method for acquiring an image of a printed circuit board with high resolution by irradiating the printed circuit board with X-rays and detecting the X-rays transmitted through the printed circuit board with the X-ray detection unit. Proposed.

JP 2013-224857 A

One field in which it is desired to inspect a product non-destructively is the field of inspecting a product including a laminate formed by bonding a first layer and a second layer through an adhesive. .
For example, in a paper container for containing contents such as confectionery, first, a paper blank plate for forming the container is prepared. The blank plate includes a plurality of regions partitioned along ruled lines that constitute the upper surface, the lower surface, and the plurality of side surfaces of the container. Next, the blank plate is folded along a part of the ruled lines, and an adhesive is provided between regions facing each other in the folded blank plate, thereby fixing one region and the other region of the blank plate to each other. As a result, a laminate in which at least two regions of the blank plate are bonded via an adhesive is obtained. In the present specification, two regions bonded via an adhesive are also referred to as a first layer and a second layer. Thereafter, a blank plate in the form of a laminate is boxed along the ruled line to produce a container, and the container is filled with contents such as confectionery.
In the manufacturing process of such a container, when the amount and position of the adhesive in the laminate are inappropriate, when the container is manufactured by making a blank plate in the form of a laminate, The layer may peel off. In order to prevent such a process failure from occurring, it is desirable to non-destructively inspect whether or not an adhesive is properly provided between the first layer and the second layer for all the laminated bodies. On the other hand, as a material constituting the blank plate, a material such as paper that does not transmit visible light is generally used. Therefore, in order to confirm the presence or absence of the adhesive between the first layer and the second layer made of paper or the like, electromagnetic waves such as X-rays that can pass through the paper are used.

  By the way, the blank plate and the adhesive are usually made of an organic material. For this reason, when X-rays are irradiated to the laminate including the blank plate and the adhesive, the X-rays are transmitted almost uniformly through the laminate regardless of the presence or absence of the adhesive. In addition, from the viewpoint of safety, care must be taken in handling X-rays. Therefore, X-rays that are mainly used in conventional non-destructive inspection are used for inspecting products that are transparent to X-rays and that are produced in large quantities, such as laminates containing blank plates and adhesives. Is not suitable.

  The present invention has been made in consideration of such points, and can accurately analyze the position of the adhesive provided between the first layer and the second layer of the laminated body in a nondestructive manner. An object of the present invention is to provide a method for inspecting a laminate and an inspection apparatus for the laminate.

  The present invention provides an inspection method for inspecting whether or not an adhesive is provided between a first layer and a second layer in a laminate including a first layer and a second layer, the first layer side An irradiation step of irradiating the laminate with electromagnetic waves, an electromagnetic wave reflected by the laminate, or a detection step of detecting the intensity of electromagnetic waves transmitted through the laminate, and the result of the detection step. An analysis step for analyzing the position where the adhesive is provided in the body, wherein the analysis step is obtained as a result of the detection step, the first variable is a position on the laminate, and the second variable is This is an inspection method performed based on the data of the electromagnetic wave intensity.

  In the inspection method according to the present invention, the electromagnetic wave applied to the laminate in the irradiation step may be an electromagnetic wave having a frequency range of 0.1 THz to 3 THz.

  In the inspection method according to the present invention, the adhesive may be an aqueous adhesive that is soluble in water or dispersible in water.

  In the irradiation step of the inspection method according to the present invention, electromagnetic waves are irradiated to a plurality of regions in the plane of the laminate, and in the detection step, the electromagnetic waves reflected by the plurality of regions, or the plurality of regions are detected. The intensity of the transmitted electromagnetic wave is detected, and in the analysis step, an adhesive is provided by assigning a pixel density corresponding to the intensity of the electromagnetic wave detected in the detection step to each of the plurality of corresponding regions. An image indicating the position where the image is displayed may be created.

  The present invention is a method for producing a laminate including a first layer and a second layer, the step of applying an adhesive to at least one of the first layer and the second layer, and via the adhesive Bonding the first layer and the second layer together to form the laminate, irradiating the laminate with electromagnetic waves from the first layer side, and electromagnetic waves reflected by the laminate Or a detection step of detecting the intensity of the electromagnetic wave transmitted through the laminate, and an analysis step of analyzing the position where the adhesive is provided in the laminate based on the result of the detection step, The analysis step is a manufacturing method performed based on data obtained as a result of the detection step and having a first variable as a position on the laminate and a second variable as an electromagnetic wave intensity.

  The present invention is an inspection apparatus for inspecting whether or not an adhesive is provided between a first layer and a second layer in a laminate including a first layer and a second layer, the first layer side Based on the result of detection by the detection unit, an irradiation unit that irradiates the laminate with electromagnetic waves, an electromagnetic wave reflected by the laminate, or a detection unit that detects the intensity of electromagnetic waves transmitted through the laminate, An analysis unit that analyzes a position where the adhesive is provided in the laminate, and the analysis unit uses a first variable obtained as a result of detection by the detection unit as a position on the laminate. The inspection apparatus analyzes a position where the adhesive is provided in the laminate based on data in which the second variable is the intensity of electromagnetic waves.

  ADVANTAGE OF THE INVENTION According to this invention, the position of the adhesive agent provided between the 1st layer and 2nd layer of a laminated body can be analyzed accurately with nondestructiveness.

Fig.1 (a) is a top view which shows the blank board for producing a container, FIG.1 (b) is a top view which shows the laminated body obtained by folding the blank board shown to Fig.1 (a). FIG. 2 is a perspective view showing a container obtained by box-making a blank plate in the form of a laminate shown in FIG. FIG. 3 is a cross-sectional view showing a case where the laminate shown in FIG. 1B is cut along line III-III. FIG. 4 is a diagram showing an inspection apparatus according to the embodiment of the present invention. FIGS. 5A to 5C are diagrams illustrating electromagnetic waves reflected by the first stacked region of the stacked body. FIGS. 6A to 6D are views showing electromagnetic waves reflected by the second laminated region of the laminated body. FIG. 7 is a diagram illustrating a waveform of an electromagnetic wave reflected by a laminated body. FIG. 8 is a diagram illustrating an image obtained by assigning a pixel density corresponding to the intensity of the electromagnetic wave detected in the detection step to each of a plurality of corresponding regions. FIG. 9 is a view showing a modification of the waveform of the electromagnetic wave reflected by the laminate. FIG. 10 is a diagram illustrating a modified example of an image obtained by assigning a pixel density corresponding to the intensity of the electromagnetic wave detected in the detection step to each of a plurality of corresponding regions. FIG. 11 is a view showing a modification of the inspection apparatus according to the embodiment of the present invention. FIG. 12 is a diagram illustrating a waveform of an electromagnetic wave reflected by a laminated body. FIG. 13 is a diagram showing an image obtained by assigning a pixel density corresponding to the intensity of the electromagnetic wave detected in the detection step to each of a plurality of corresponding regions. FIG. 14 is a diagram showing an image obtained in Example 1.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

(Blank board, laminate and container)
First, the laminated body 30B including the first layer and the second layer and the members related to the laminated body 30B, which are targets for performing the inspection method using the inspection apparatus 10 according to the present embodiment, will be described. Fig.1 (a) is a top view which shows 30 A of blank plates for producing the container 30, FIG.1 (b) is a top view which shows the laminated body 30B obtained by folding 30 A of blank plates. Moreover, FIG. 2 is a perspective view which shows the container 30 obtained by box-producing the blank board of the form of the laminated body 30B.

  As shown in FIG. 2, the container 30 includes an upper surface 31 and a lower surface 32 that face each other, and a first side surface 33, a second side surface 34, a third side surface 35, and a fourth side surface that are located between the upper surface 31 and the lower surface 32. 36. Further, as shown in FIG. 1A, a joining piece 37 is connected to the first side surface 33. The joining piece 37 is a part used as a glue margin when the first side surface 33 and the fourth side surface 36 are connected by adhesion. Further, as shown in FIG. 1A, a joining piece or a flap may be further connected to the first side surface 33, the second side surface 34, and the fourth side surface 36.

  The laminate 30B shown in FIG. 1B folds the blank plate 30A along the ruled line between the first side surface 33 and the second side surface 34 and the ruled line between the third side surface 35 and the fourth side surface 36. Is obtained. As shown by a dotted line in FIG. 1B, the blank plate 30 </ b> A is folded so that the joining piece 37 is located inside the fourth side surface 36. As indicated by reference numeral 46, an adhesive 46 is provided between the joining piece 37 and the fourth side face 36, and the joining piece 37 and the fourth side face 36 are bonded together by the adhesive 46. FIG. 1B shows an example in which the adhesive 46 is discretely provided at regular intervals between the joining piece 37 and the fourth side surface 36. However, the arrangement of the adhesive 46 is particularly limited. There is no limit. For example, the adhesive 46 may be provided discretely at irregular intervals. The adhesive 46 may be provided so as to continuously extend along the shape of the joining piece 37.

  FIG. 3 is a cross-sectional view showing a case where the stacked body 30B shown in FIG. 1B is viewed along the line III-III. As shown in FIG. 3, in the region where the joining piece 37 exists, the stacked body 30 </ b> B includes the fourth side surface 36, the joining piece 37 and the third side surface 35, and the fourth side surface 36 and the joining piece 37 that are sequentially stacked. And an adhesive 46 provided therebetween. In the present application, the layers bonded to each other by the adhesive 46 are also referred to as a first layer and a second layer, and are adjacent to the first layer or the second layer on the side farther from the adhesive 46. The layer is also referred to as a third layer. In the present embodiment, in the following description, the fourth side surface 36 will be referred to as the first layer 41, the joining piece 37 will be referred to as the second layer 42, and the third side surface 35 adjacent to the joining piece 37 will be described. This may be referred to as the third layer 43.

  In the following description, a region including the first layer 41 and the second layer 42 and not including the adhesive 46 in the stacked body 30 </ b> B is referred to as a first stacked region 47. Further, in the stacked body 30B, a region including the first layer 41 and the second layer 42 and the adhesive 46 provided between the first layer 41 and the second layer 42 is defined as a second stacked region 48. Called. As shown in FIG. 3, an air layer 49 made of air may exist between the first layer 41 and the second layer 42 in the first stacked region 47. An air layer 49 may also exist between the second layer 42 and the third layer 43.

  Next, the material which comprises each layer 41 and 42 and the adhesive agent 46 is demonstrated.

  The material constituting the first layer 41 and the second layer 42, that is, the material constituting the blank plate 30A can be bonded by the adhesive 46 and can provide appropriate rigidity as the container 30. Selected. For example, the first layer 41 and the second layer 42, that is, the blank plate 30A includes paper or a plastic sheet. The thickness of the first layer 41 and the second layer 42, that is, the thickness of the blank plate 30A is, for example, in the range of 0.3 mm to 1.1 mm.

As the adhesive 46, an adhesive that can reflect or absorb electromagnetic waves used in the inspection apparatus 10 to be described later is used. For example, as the adhesive 46, an aqueous adhesive that can be dissolved in water or dispersed in water can be used. Further, as the adhesive 46, a general adhesive in which synthetic resin, synthetic rubber or the like is dissolved in an organic solvent may be used. Examples of the organic solvent include acetone, methyl acetate, ethyl acetate and the like.
As an example of the aqueous adhesive dispersible in water, an aqueous emulsion adhesive obtained by dispersing a polymer of a synthetic resin in water can be given. In this case, as described later, when the adhesive 46 is in a dry state, the electromagnetic waves are mainly reflected by the adhesive 46. On the other hand, when the adhesive 46 is not dry, the electromagnetic waves are mainly absorbed by the adhesive 46. The “dry state” means that the content ratio of water in the adhesive 46 is less than 5% by weight. In addition, the “not dry state” means that the content ratio of water in the adhesive 46 is 5% by weight or more.

(Manufacturing method of laminate and container)
Next, an example of a method for manufacturing the above-described laminate 30B and container 30 will be described.

  First, a blank plate 30A shown in FIG. 1 (a) is prepared. Next, as shown in FIG. 1B, the blank plate 30 </ b> A is folded so that the fourth side surface 36 that becomes the first layer 41 and the joining piece 37 that becomes the second layer 42 overlap each other. In addition, an adhesive 46 is applied to at least one of the first layer 41 and the second layer 42. The adhesive 46 is applied to a predetermined position of the first layer 41 or the second layer 42. Thereafter, the first layer 41 and the second layer 42 are bonded together via the adhesive 46. Thereby, the laminated body 30B in which the first layer 41 and the second layer 42 are bonded can be obtained. The adhesive 46 may be applied to the blank plate 30A before being folded, or may be applied to the blank plate 30A after being folded.

  Next, an inspection process for inspecting whether or not the adhesive 46 is appropriately provided between the first layer 41 and the second layer 42 in the stacked body 30B is performed. Specifically, the position where the adhesive 46 is provided in the laminated body 30B is analyzed using the inspection apparatus 10 described later. Then, it is determined whether or not the analyzed position of the adhesive 46 matches a predetermined position of the adhesive 46. The laminated body 30B determined that the position of the adhesive 46 is inappropriate is discarded. In this way, it is possible to manufacture the laminate 30B in which the adhesive 46 is provided at an appropriate position.

  Then, the container 30 is produced by box-making the blank board of the form of the laminated body 30B along a ruled line, and the inside of the container 30 is filled with contents such as confectionery. In this way, the container 30 filled with contents such as confectionery can be obtained.

  Hereinafter, a method for inspecting the stacked body 30B for inspecting whether or not the adhesive 46 is appropriately provided between the first layer 41 and the second layer 42 will be described in detail. First, the inspection apparatus 10 for performing the inspection method will be described with reference to FIG.

(Inspection equipment)
As shown in FIG. 4, the inspection apparatus 10 inspects a plurality of stacked bodies 30 </ b> B placed on a transport unit 18 made of a belt conveyor or the like and transported in the direction of arrow T according to the present embodiment. The method is configured to be performed sequentially. Specifically, the inspection apparatus 10 includes an irradiation unit 12 that irradiates the electromagnetic wave L1 to the multilayer body 30B from the first layer 41 side, a detection unit 14 that detects the intensity of the electromagnetic wave L2 reflected by the multilayer body 30B, and a detection And an analysis unit 20 that analyzes the position where the adhesive 46 is provided in the laminate 30B based on the detection result of the unit 14. FIG. 4 shows an example in which the electromagnetic wave L1 is incident on the multilayer body 30B from a direction inclined with respect to the normal direction of the first layer 41 of the multilayer body 30B. However, the present invention is not limited to this. As long as the electromagnetic wave L2 obtained by reflection from the laminated body 30B can be appropriately detected, the incident angle of the electromagnetic wave L1 and the positions of the irradiation unit 12 and the detection unit 14 are not particularly limited. In each stacked body 30B, preferably, the arrangement direction of the plurality of adhesives 46 provided between the first layer 41 and the second layer 42 of the stacked body 30B matches the transport direction T of the transport unit 18. And placed on the transport unit 18.

  The irradiation unit 12 is configured to generate a terahertz wave having a frequency range of 0.1 THz to 3 THz as an electromagnetic wave L1 and radiate it toward the stacked body 30B. When a plurality of adhesives 46 are provided in a discrete manner, the beam diameter of the electromagnetic wave L1 is preferably adjusted to be smaller than the distance between two adjacent adhesives 46. In order to adjust the traveling direction and beam diameter of the electromagnetic wave L1, the irradiating unit 12 may include an optical system.

  The frequency range of the electromagnetic wave L1 generated in the irradiation unit 12 may be 1 THz to 2 THz. This makes it easier for the electromagnetic wave L1 to pass through the layers 41 and 42 of the stacked body 30B.

  As a generation system of the electromagnetic wave L1 composed of terahertz waves, a generation system using a photoconductive antenna or a semiconductor can be used. In addition, as a generation system, a generation system that generates an electromagnetic wave using a nonlinear optical effect such as optical parametric or difference frequency mixing generated by irradiating a nonlinear optical crystal with laser light can be used. In addition, examples of the generation system include a quantum cascade laser (QCL), a resonant tunnel diode (RTD), a gyrotron, and a free electron laser (FEL). The nonlinear optical crystal is a crystal that responds nonlinearly, that is, not proportional to the electromagnetic field of light when intense light such as laser light is incident. The nonlinear optical effect is a nonlinear response, that is, a response that is not proportional to the electromagnetic field of light. The optical parametric and difference frequency mixing described above are a kind of nonlinear optical effect.

  In this embodiment, an example in which a generation system that generates a pulsed terahertz wave by irradiating a nonlinear optical crystal with ultrashort pulse light such as a femtosecond pulse will be described. The pulse width of the terahertz wave is, for example, 5 ns or less. Further, the repetition cycle of the terahertz wave pulse is, for example, 50 Hz or less.

  As will be described later, the detection unit 14 is configured to be able to detect the intensity of electromagnetic waves reflected by the layers 41, 42, 43 and the adhesive 46 of the laminate 30B. The specific configuration of the detection unit 14 is not particularly limited, and a known detection unit used in terahertz time domain spectroscopy can be used.

(Inspection method for laminates)
Next, a method for inspecting the stacked body 30 </ b> B using the inspection apparatus 10 will be described with reference to FIGS. 5 to 8. Here, a case where the adhesive 46 included in the stacked body 30B is in a dry state will be described.

[Irradiation process]
First, an irradiation step of irradiating the laminated body 30B with the electromagnetic wave L1 from the first layer 41 side is performed. For example, as described above, a pulsed terahertz wave generated at a predetermined repetition period is applied to the stacked body 30B as the electromagnetic wave L1.

  In the irradiation step, the electromagnetic wave L1 is irradiated toward a predetermined region of the laminate 30B where the adhesive 46 is to be applied. Specifically, as illustrated in FIG. 4, the electromagnetic wave L <b> 1 is irradiated toward a region where the joining piece 37 serving as the second layer 42 is located in the stacked body 30 </ b> B. Here, as described above, in the stacked body 30 </ b> B, the arrangement direction of the plurality of adhesives 46 provided between the first layer 41 and the second layer 42, that is, the direction in which the joining pieces 37 extend is the conveyance of the conveyance unit 18. It is placed on the transport unit 18 so as to coincide with the direction T. For this reason, the electromagnetic wave L1 radiated from the irradiation unit 12 is transferred to the first stacked region 47 that does not include the adhesive 46 and the second stacked region 48 that includes the adhesive 46 according to the movement of the stacked body 30B by the transport unit 18. It will be irradiated alternately.

  In the irradiation step, the electromagnetic wave L1 may be irradiated from the irradiation unit 12 toward the stacked body 30B so as to scan a plurality of regions in the plane of the stacked body 30B with the electromagnetic wave L1. For example, the direction of the electromagnetic wave L1 radiated from the irradiation unit 12 may be periodically and repeatedly changed along a direction intersecting the transport direction T of the transport unit 18, for example, a direction orthogonal to the transport direction T of the transport unit 18. Good. As a result, the electromagnetic wave L1 can be applied to a plurality of regions that spread two-dimensionally in the plane of the stacked body 30B. This makes it possible to detect the intensity of the electromagnetic waves reflected by the plurality of regions in the plane of the stacked body 30B in the detection step described later.

[Detection process]
Next, a detection step of detecting the intensity of the electromagnetic wave reflected by the first stacked region 47 or the second stacked region 48 of the stacked body 30B is performed. First, the intensity of the electromagnetic wave L2 that can be detected by the detection unit 14 when the electromagnetic wave L1 is applied to the first stacked region 47 of the stacked body 30B will be described with reference to FIGS. FIGS. 5A to 5C respectively show typical paths among the paths in which the electromagnetic wave L1 irradiated to the first stacked region 47 is reflected and returned as the electromagnetic wave L2. 5A to 5C, the electromagnetic waves that are reflected by the first laminated region 47 and reach the detection unit 14 are indicated by reference numerals L21a, L22a, and L23a, respectively.
An electromagnetic wave L <b> 21 a illustrated in FIG. 5A is an electromagnetic wave that is reflected by the first layer 41 of the first stacked region 47 and reaches the detection unit 14.
An electromagnetic wave L <b> 22 a illustrated in FIG. 5B is an electromagnetic wave that passes through the first layer 41 of the first stacked region 47 and is reflected by the second layer 42 of the first stacked region 47 to reach the detection unit 14.
The electromagnetic wave L <b> 23 a shown in FIG. 5C passes through the first layer 41 and the second layer 42 in the first stacked region 47 and is then reflected by the third layer 43 in the first stacked region 47 to reach the detection unit 14. Electromagnetic waves.

  As described above, the detection unit 14 detects the above-described electromagnetic waves L21a, L22a, and L23a as electromagnetic waves reflected by the first stacked region 47. In addition, as described above, when the electromagnetic wave L1 irradiated to the stacked body 30B is a pulsed electromagnetic wave generated at a predetermined repetition period, the detection unit 14 has the same period as the generation period of the electromagnetic wave L1. Electromagnetic waves L21a, L22a, and L23a are repeatedly detected. Accordingly, in the detection unit 14, the time average of the total intensity of the electromagnetic waves L21a, L22a, and L23a repeatedly detected is the intensity data of the electromagnetic waves reflected by one region of the first laminated region 47 irradiated with the electromagnetic waves L1. As obtained.

Next, the intensity of the electromagnetic wave L2 that can be detected by the detection unit 14 when the electromagnetic wave L1 is applied to the second stacked region 48 of the stacked body 30B will be described with reference to FIGS. FIGS. 6A to 6D respectively show typical paths among paths where the electromagnetic wave L1 irradiated to the second stacked region 48 is reflected and returned as the electromagnetic wave L2. 6A to 6D, the electromagnetic waves that are reflected by the second stacked region 48 and reach the detection unit 14 are indicated by reference numerals L21b, L26b, L22b, and L23b, respectively.
An electromagnetic wave L <b> 21 b illustrated in FIG. 6A is an electromagnetic wave that is reflected by the first layer 41 of the second stacked region 48 and reaches the detection unit 14.
An electromagnetic wave L <b> 26 b illustrated in FIG. 6B is an electromagnetic wave that passes through the first layer 41 in the second stacked region 48 and is reflected by the adhesive 46 in the second stacked region 48 to reach the detection unit 14.
The electromagnetic wave L22b shown in FIG. 6C is transmitted through the first layer 41 and the adhesive 46 in the second stacked region 48 and then reflected by the second layer 42 in the second stacked region 48 to reach the detection unit 14. It is.
The electromagnetic wave L23b shown in FIG. 6 (d) passes through the first layer 41, the adhesive 46 and the second layer 42 in the second stacked region 48, and is then reflected and detected by the third layer 43 in the second stacked region 48. The electromagnetic wave reaches the portion 14.

  As described above, the detection unit 14 detects the above-described electromagnetic waves L21b, L26b, L22b, and L23b as electromagnetic waves reflected by the second stacked region 48. In addition, as described above, when the electromagnetic wave L1 irradiated to the stacked body 30B is a pulsed electromagnetic wave generated at a predetermined repetition period, the detection unit 14 has the same period as the generation period of the electromagnetic wave L1. Electromagnetic waves L21b, L26b, L22b, and L23b are repeatedly detected. Therefore, in the detection unit 14, the time average of the total values of the intensities of the electromagnetic waves L21b, L26b, L22b, and L23b that are repeatedly detected is the electromagnetic wave reflected by one region of the second stacked region 48 irradiated with the electromagnetic wave L1. Obtained as intensity data.

  As described above, the adhesive 46 in the second stacked region 48 is in a dry state. For this reason, the reflectance of the electromagnetic wave in the adhesive 46 is higher than the reflectance of the electromagnetic wave in the first layer 41. Accordingly, the intensity P26b of the electromagnetic wave L26b reflected by the adhesive 46 is larger than the intensity P21b of the electromagnetic wave L21b reflected by the first layer 41. As a result, it is considered that the intensity of the electromagnetic wave reflected by one area of the second stacked area 48 is larger than the intensity of the electromagnetic wave reflected by one area of the first stacked area 47. Therefore, in the data obtained by the detection unit 14 where the first variable is the position on the stacked body 30B and the second variable is the electromagnetic wave intensity, is the adhesive 46 included in the region irradiated with the electromagnetic wave L1? Depending on how, the intensity distribution of the electromagnetic wave according to the position on the laminated body 30B is generated. FIG. 7 shows the intensity data of the electromagnetic waves reflected by the plurality of regions when the electromagnetic waves L1 are sequentially irradiated to the plurality of regions arranged along the arrangement direction of the plurality of adhesives 46, that is, the direction in which the joining pieces 37 extend. The waveform W2 obtained by plotting with respect to the position of the area is shown. As shown in FIG. 7, in the waveform W2, the portions having the intensity P2a and the portions having the intensity P2b appear alternately.

[Analysis process]
Next, based on the result of the above-described detection process, an analysis process for analyzing the position where the adhesive 46 is provided in the laminate 30B is performed. The analysis step is performed based on data obtained as a result of the detection step, in which the first variable is a position on the stacked body 30B, that is, the coordinates on the stacked body 30B, and the second variable is the intensity of the electromagnetic wave. Here, an example in which the position where the adhesive 46 is provided is analyzed based on the above-described waveform W2 created by plotting the data obtained in the detection step against the position on the stacked body 30B. To do.

  Due to the electromagnetic wave L26b reflected by the adhesive 46 and reaching the detection unit 14, the intensity of the electromagnetic wave reflected by the second stacked region 48 is greater than the intensity of the electromagnetic wave reflected by the first stacked region 47. Therefore, in the waveform W2 shown in FIG. 7, the portion of the intensity P2b that is larger than the intensity P2a corresponds to the electromagnetic wave reflected by the second stacked region 48, and the portion of the intensity P2a is the first stacked region 47. It is a part corresponding to the electromagnetic wave reflected by. In addition, the position and width of the portion having the strength P2b in the waveform W2 corresponds to the region where the adhesive 46 is provided in the stacked body 30B, that is, the position and width of the second stacked region 48. As described above, according to the present embodiment, the adhesive 46 is provided in the laminate 30B based on the distribution of the intensity of the electromagnetic wave when the intensity of the electromagnetic wave reflected by the laminate 30B is plotted against the position. Can be analyzed. In FIG. 7, the portion having the intensity P2z is a portion corresponding to the electromagnetic wave that reaches the transport unit 18 and is reflected by the transport unit 18 without passing through the stacked body 30B.

  By the way, when a plurality of regions in the plane of the laminate 30B are scanned by the electromagnetic wave L1 in the irradiation step, data regarding the electromagnetic wave intensity distribution as shown in FIG. 7 is obtained two-dimensionally. That is, it is possible to obtain data on the distribution of the intensity of the electromagnetic wave reflected by the plurality of regions in the plane of the stacked body 30B. In this case, in the analysis step, an image G shown in FIG. 8 can be created by assigning a pixel density corresponding to the detected electromagnetic wave intensity to each of the plurality of regions of the corresponding stacked body 30B. The “pixel density” is a density of the pixel when the region of the stacked body 30B that is an analysis target using the electromagnetic wave L1 is regarded as one pixel. In the image G shown in FIG. 8, the pixel density regions corresponding to the intensity P2b are discretely arranged in a line in the pixel density areas corresponding to the intensity P2a. This means that in the stacked body 30B, the second stacked regions 48 including the adhesive 46 are discretely aligned in a range surrounded by the first stacked regions 47. That is, the image G can show the position where the adhesive 46 is provided in the laminate 30B. As described above, according to the present embodiment, the position where the adhesive 46 is provided in the stacked body 30B can be expressed more clearly by creating the image G based on the data related to the distribution of the intensity of the electromagnetic wave. it can. FIG. 8 shows an example in which the image G is a black and white image, and the corresponding region is expressed as whitish as the intensity of the detected electromagnetic wave is larger. That is, an example has been shown in which the pixel density contains more white components as the intensity of electromagnetic waves increases. However, the relationship between the intensity of the electromagnetic wave and the pixel density is not particularly limited as long as the image G can visually represent the distribution of the intensity of the electromagnetic wave according to the intensity of the detected electromagnetic wave. For example, as the intensity of electromagnetic waves increases, the pixel density may include more black components or other color components.

  As shown in FIG. 8, the image G includes a reflection region positioned around the bonding piece 37, the region of the stacked body 30 </ b> B where the intensity of the reflected electromagnetic wave is P <b> 2 c, and the surroundings of the stacked body 30 </ b> B. A region of the transport unit 18 where the intensity of the electromagnetic wave thus generated is P2z may also be shown. That is, in the irradiation step, the electromagnetic wave L1 may be irradiated not only in the region where the joining piece 37 is present in the stacked body 30B but also in the peripheral region thereof, and in the detection step, depending on the peripheral region. You may detect the reflected electromagnetic waves. This makes it possible to grasp the position of the adhesive 46 in the stacked body 30B more clearly.

  Note that various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted. In addition, when it is clear that the operational effects obtained in the above-described embodiment can be obtained in the modified example, the description thereof may be omitted.

(Modification example of electromagnetic wave)
In the above-described embodiment, an example in which terahertz waves are used as electromagnetic waves has been described. However, the present invention is not limited to this, and as long as it can pass through the first layer 41 and the second layer 42 of the laminate 30B and can be reflected by the adhesive 46 in a dry state, as an electromagnetic wave, infrared rays, etc. An electromagnetic wave having a frequency outside the frequency range of 0.1 THz to 3 THz may be used.

(Modification of adhesive state)
Further, in the above-described embodiment, an example in which the adhesive 46 included in the stacked body 30B is in a dry state is shown. However, even when the adhesive 46 included in the laminate 30B is not dry, the position of the adhesive 46 is analyzed nondestructively with high accuracy using the inspection apparatus 10 as described below. It is possible. FIG. 9 shows a waveform W2 obtained by plotting the intensity data of the electromagnetic wave reflected by the plurality of regions of the multilayer body 30B with respect to the position of each region in the present modification.

  When the adhesive 46 is not dry, the electromagnetic wave L1 that passes through the first layer 41 of the second stacked region 48 and reaches the adhesive 46 is mainly absorbed by the adhesive 46. For this reason, in this modification, as shown in FIG. 9, the intensity P2b of the electromagnetic wave reflected by the second stacked region 48 is smaller than the intensity P2a of the electromagnetic wave reflected by the first stacked region 47. That is, there is a difference between the intensity P2b and the intensity P2a. Therefore, also in this modification, the position where the adhesive 46 is provided in the laminated body 30B is based on the distribution of the electromagnetic wave intensity when the intensity of the electromagnetic wave reflected by the laminated body 30B is plotted against the position. Can be analyzed.

  FIG. 10 is a diagram illustrating an example of an image G obtained when the adhesive 46 is not dry. Also in this modification, the position where the adhesive 46 is provided in the laminated body 30B can be expressed more clearly by creating the image G based on the data regarding the distribution of the electromagnetic wave intensity. In this modified example, as shown in FIG. 10, the pixel density contrast between the portion of intensity P2a and the portion of intensity 2Pb is reversed as compared with the case of FIG.

(Example using transmitted electromagnetic waves)
In the above-described embodiment, the example in which the electromagnetic wave L2 reflected by the stacked body 30B is detected is shown. However, the present invention is not limited to this, and as illustrated in FIG. 11, the electromagnetic wave L3 transmitted through the stacked body 30B may be detected by the detection unit 14. In this modification, the transport unit 18 for transporting the stacked body 30B is made of a material having translucency.

  When the adhesive 46 is in a dry state, most of the electromagnetic waves reaching the adhesive 46 are reflected by the adhesive 46. When the adhesive 46 is not dry, most of the electromagnetic waves reaching the adhesive 46 are absorbed by the adhesive 46. Therefore, in both cases where the adhesive 46 is in a dry state and in the case where the adhesive 46 is not dry, the electromagnetic wave L3 that passes through the second stacked region 48 of the stacked body 30B and reaches the detection unit 14. It can be said that the intensity P3b is extremely smaller than the intensity P3a of the electromagnetic wave L3 that passes through the first laminated region 47 of the laminated body 30B and reaches the detection unit 14. A waveform W3 shown in FIG. 12 indicates the intensity data of the electromagnetic waves transmitted through the plurality of regions when the electromagnetic waves L1 are sequentially irradiated to the plurality of regions arranged along the arrangement direction of the plurality of adhesives 46, that is, the direction in which the bonding pieces 37 extend. Are obtained by plotting the values for the positions of the respective regions. As shown in FIG. 12, also in this modified example, in the waveform W3, portions having the intensity P3a and portions having the intensity P3b appear alternately. Therefore, based on this waveform W3, the position where the adhesive 46 is provided in the laminate 30B can be analyzed.

  FIG. 13 is a diagram illustrating an example of an image G obtained in the present modification. Also in this modification, the position where the adhesive 46 is provided in the laminated body 30B can be expressed more clearly by creating the image G based on the data regarding the distribution of the electromagnetic wave intensity.

(Modification of irradiation unit and detection unit)
Further, in the above-described embodiment, the example in which the electromagnetic wave L1 is irradiated from the irradiation unit 12 toward the stacked body 30B so as to scan a plurality of regions in the plane of the stacked body 30B with the electromagnetic wave L1 is shown. However, a specific irradiation method is not particularly limited as long as the electromagnetic wave L1 can be irradiated to a plurality of regions in the plane of the stacked body 30B. For example, the irradiation unit 12 may be configured to irradiate the electromagnetic wave L1 at once to a plurality of regions in the plane of the stacked body 30B. Moreover, the detection part 14 may be comprised so that the intensity | strength of the electromagnetic waves reflected by the several area | region in the surface of the laminated body 30B and returning substantially simultaneously can each be detected independently.

(Other variations)
Moreover, in this Embodiment mentioned above, the laminated body 30B obtained by folding the blank board 30A was shown as an example of the laminated body inspected by the test | inspection apparatus 10. FIG. However, the adhesive 46 includes the first layer 41 and the second layer 42 through which the electromagnetic wave L1 radiated from the irradiation unit 12 of the inspection apparatus 10 can pass, and the adhesive 46 is interposed between the first layer 41 and the second layer 42. As long as it is provided, the specific configuration of the laminate is not particularly limited. For example, a laminate including a plurality of layers provided between the irradiation unit 12 and the adhesive 46 or a laminate including a plurality of layers provided between the adhesive 46 and the transport unit 18 is used as an inspection apparatus. 10 can also be used for inspection.

  Further, in the above-described embodiment and modification examples, a waveform with a horizontal axis or a two-dimensional image is created based on data obtained as a result of the detection process, and the waveform or image is analyzed. Thus, an example in which the presence or absence of the adhesive 46 is determined is shown. However, the specific analysis method is not particularly limited. For example, the presence of the adhesive 46 may be determined by analyzing the data itself without creating a waveform or an image.

  In addition, although some modified examples with respect to the above-described embodiment have been described, naturally, a plurality of modified examples can be applied in combination as appropriate.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.

Example 1
First, a first layer 41 and a second layer 42 made of resin-coated paper used as a material for a paper container were prepared. Next, the adhesive 46 was applied in a line at predetermined intervals to predetermined positions on the surface of the second layer 42. As the adhesive 46, an aqueous emulsion adhesive CN135 manufactured by Konishi Co., Ltd. was used. Thereafter, the first layer 41 and the second layer 42 were bonded together with an adhesive 46 to form a stacked body 30B.

  After the adhesive 46 of the laminated body 30B was sufficiently dried to be in a dry state, the laminated body 30B was placed on the transport unit 18 of the inspection apparatus 10. Then, the terahertz wave was irradiated to the some area | region of the laminated body 30B using the irradiation part 12 from the 1st layer 41 side. Moreover, the terahertz wave reflected by the several area | region of the laminated body 30B was each detected using the detection part 14. FIG. Next, an image G shown in FIG. 14 was created by assigning a pixel density corresponding to the detected electromagnetic wave intensity to each of a plurality of regions of the corresponding laminate 30B. As shown in FIG. 14, in the image G, a density difference clearly appears between a region where the adhesive 46 is provided and a region where the adhesive 46 is not provided.

DESCRIPTION OF SYMBOLS 10 Inspection apparatus 12 Irradiation part 14 Detection part 18 Conveyance part 20 Analysis part 30 Container 30A Blank board 30B Laminate 41 1st layer 42 2nd layer 46 Adhesive 47 1st lamination area 48 2nd lamination area

Claims (6)

In the laminate including the first layer and the second layer, an inspection method for inspecting whether an adhesive is provided between the first layer and the second layer,
An irradiation step of irradiating the laminated body with electromagnetic waves in a frequency range of 0.1 THz to 3 THz from the first layer side;
A detection step of detecting an electromagnetic wave reflected by the laminate or an electromagnetic wave transmitted through the laminate;
Analyzing the position where the adhesive is provided in the laminate based on the result of the detection step, and
The analysis step is performed based on data obtained as a result of the detection step, the first variable being a position on the laminate and the second variable being the electromagnetic wave intensity ,
The inspection method , wherein the adhesive is an aqueous adhesive that is soluble in water or dispersible in water, and the water content in the adhesive is 5% by weight or more . The inspection method according to claim 1, wherein the first layer and the second layer include paper or a plastic sheet. In the irradiation step, electromagnetic waves are irradiated to a plurality of regions in the plane of the laminate,
In the detection step, the intensity of the electromagnetic wave reflected by the plurality of regions or the intensity of the electromagnetic wave transmitted through the plurality of regions is detected, respectively.
In the analysis step, an image showing the position where the adhesive is provided is created by assigning a pixel density corresponding to the intensity of the electromagnetic wave detected in the detection step to each of the corresponding regions. The inspection method according to claim 1 or 2 . The stacked body includes a first stacked region including the first layer and the second layer and not including the adhesive, the first layer and the second layer, the first layer, and the second layer. And an adhesive provided between the layers, at least a second lamination region,
The intensity of the electromagnetic wave reflected by the second laminated region or the electromagnetic wave transmitted through the second laminated region is greater than the intensity of the electromagnetic wave reflected by the first laminated region or the electromagnetic wave transmitted through the second laminated region. The inspection method according to any one of claims 1 to 3, wherein the inspection method is small. A method for producing a laminate including a first layer and a second layer,
Applying an adhesive to at least one of the first layer and the second layer;
Bonding the first layer and the second layer via the adhesive to form the laminate;
An irradiation step of irradiating the laminated body with electromagnetic waves in a frequency range of 0.1 THz to 3 THz from the first layer side;
A detection step of detecting an electromagnetic wave reflected by the laminate or an electromagnetic wave transmitted through the laminate;
Analyzing the position where the adhesive is provided in the laminate based on the result of the detection step, and
The analysis step is performed based on data obtained as a result of the detection step, the first variable being a position on the laminate and the second variable being the electromagnetic wave intensity ,
The said adhesive is a water-based adhesive which can be melt | dissolved in water, or is dispersible in water, and the content rate of the water in the said adhesive is 5 weight% or more . In the laminate including the first layer and the second layer, an inspection apparatus that inspects whether an adhesive is provided between the first layer and the second layer,
An irradiator that irradiates the laminated body with electromagnetic waves in a frequency range of 0.1 THz to 3 THz from the first layer side;
A detection unit for detecting the intensity of the electromagnetic wave reflected by the laminate or the electromagnetic wave transmitted through the laminate;
Based on the detection result by the detection unit, an analysis unit for analyzing the position where the adhesive is provided in the laminate, and
The analysis unit is provided with the adhesive in the laminate based on data obtained as a result of detection by the detection unit and having a first variable as a position on the laminate and a second variable as an electromagnetic wave intensity. is position to analyze that,
The inspection apparatus is an aqueous adhesive that is soluble in water or dispersible in water, and the content ratio of water in the adhesive is 5% by weight or more .