WO2013054719A1 - Inspection device for seal part as in absorbent article, and inspection method - Google Patents

Abstract

An inspection device for a seal part for bonding a plurality of sheets stacked in the thickness direction constituting an absorbent article, at an edge part of the absorbent article, wherein the inspection device comprises: an imaging processing unit for imaging a region, in which the seal part is formed, of one surface of the plurality of sheets, and generating data of a planar image of the region, as planar image data; a first binarization processing unit for binarizing the planar image data on the basis of a first threshold value and generating a binarized image, thereupon carrying out first binarization processing so that an image (W1) specified by one of two values in the binarized image includes a region (Ah) in which a perforated portion (h) in a perforated state is imaged in the thickness direction, within an imaged portion (A1s) of the seal part in the planar image; a second binarization processing unit for binarizing the planar image data on the basis of a second threshold value different than the first threshold value and generating a binarized image, thereupon carrying out second binarization processing so that an image (W2) specified by one of two values in the binarized image includes a region (A1dn) in which an abnormally bonded portion (1dn) where the plurality of sheets are in an unbonded state is imaged, within the imaged portion (A1s) of the seal part in the planar image; a first abnormality determination processing unit for determining whether or not there is a perforation abnormality, on the basis of the binarized image generated by the first binarization processing unit; and a second abnormality determination processing unit for determining whether or not there is a bonding abnormality, on the basis of the binarized image generated by the second binarization processing unit.

Description

Inspection device and inspection method for seal part of absorbent article

The present invention relates to an inspection apparatus and an inspection method for a seal portion related to an absorbent article such as a sanitary napkin.

Conventionally, a sanitary napkin is known as an example of an absorbent article that absorbs liquid such as excreta. Such a napkin is provided with an absorbent body mainly composed of pulp fibers, a liquid-permeable surface sheet provided by covering the absorbent body from the skin side of the wearer, and covering the absorbent body from the non-skin side. And a liquid-impermeable back sheet. And these sheets are integrally joined by the seal | sticker part formed in the part protruded outward rather than the absorber, and, thereby, an absorber is hold | maintained inside a napkin.

Such a seal portion is formed by a seal device. That is, the sealing device has a pair of rolls that are driven and rotated while facing each other's outer peripheral surfaces, and the outer peripheral surface of one of the rolls is provided with a convex portion corresponding to the shape of the outer edge portion of the napkin. Yes. Therefore, when the top sheet, the absorber, and the back sheet are passed through the roll gap between these rolls in a laminated state, the above-mentioned convex portions are in a pattern along the outer edge of the napkin. Both the top sheet and the back sheet are pressed in the thickness direction to pressure-bond these sheets, thereby forming the seal part (Patent Document 1).

JP 2007-135940 A

Here, if the pressing load when forming the seal portion is larger than necessary, the seal portion partially penetrates in the thickness direction to form a through hole, and if the through hole is large, the napkin is perforated abnormally. Become. On the other hand, when the pressing load is smaller than the required level, the seal sheet partially forms the unbonded portion of the topsheet and the backsheet, and when the unbonded portion is large, the napkin has a bonding abnormality. Become. Therefore, in the napkin production line, the size of the roll gap of the sealing device is finely adjusted to prevent these abnormalities.

However, recently, there are an increasing number of products with a partially different number of stacked sheets at the outer edge of the napkin. For these, it is difficult to suppress the occurrence of the above-mentioned abnormality by fine adjustment of the size of the roll gap. It has become. Along with this, there is an increasing need for an inspection apparatus and an inspection method capable of accurately inspecting a perforation abnormality and a joining abnormality of the seal portion.

The present invention has been made in view of the conventional problems as described above, and its purpose is to accurately inspect for abnormalities in the puncture of the seal portion and abnormal bonding in absorbent articles such as sanitary napkins. To provide an inspection apparatus and an inspection method.

The main invention for achieving the above object is:
An inspection device for a seal part that joins a plurality of sheets laminated in a thickness direction constituting an absorbent article at an outer edge part of the absorbent article,
The seal portion is formed by pressing the plurality of stacked sheets in the thickness direction at the outer edge portion,
An imaging processing unit that captures an image of an area where the seal portion is formed on one side of the plurality of sheets and generates planar image data of the area as planar image data;
When generating the binarized image by binarizing the plane image data based on the first threshold value, the image specified by one of the binaries in the binarized image is displayed on the plane. A first binarization processing unit that performs binarization processing so as to include a region in which a perforated portion in a penetrating state is imaged in the thickness direction among imaging portions of the seal portion in the image;
When generating the binarized image by binarizing the planar image data based on the second threshold value different from the first threshold value, the binarized image is specified by one of the binary values. The binarization processing is performed so that the image to be processed includes an area where the abnormally bonded portions of the plurality of sheets in the unbonded state are imaged among the imaged portions of the seal portion in the planar image. A binarization processing unit;
Based on the binarized image generated by the first binarization processing unit, a first abnormality determination processing unit that determines the presence or absence of perforation abnormality;
And a second abnormality determination processing unit that determines whether or not there is a bonding abnormality based on the binarized image generated by the second binarization processing unit. This is an inspection device.

Also,
A method for inspecting a seal part that joins a plurality of sheets laminated in a thickness direction constituting an absorbent article at an outer edge part of the absorbent article,
The seal portion is formed by pressing the plurality of stacked sheets in the thickness direction at the outer edge portion,
Imaging a region where the seal portion is formed in one side of the plurality of sheets, and generating plane image data of the region as plane image data;
When generating the binarized image by binarizing the plane image data based on the first threshold value, the image specified by one of the binaries in the binarized image is displayed on the plane. Performing a first binarization process so as to include a region in which a perforated portion in a penetrating state is imaged in the thickness direction among imaging portions of the seal portion in an image;
When generating the binarized image by binarizing the planar image data based on the second threshold value different from the first threshold value, the binarized image is specified by one of the binary values. The second binarization process is performed so that the image to be processed includes an area in which the abnormal bonding portion in which the plurality of sheets are not bonded is imaged among the imaging portions of the seal portion in the planar image. To do and
Based on the binarized image generated by the first binarization process, determining whether there is a hole abnormality;
And determining whether or not there is a bonding abnormality based on a binarized image generated by the second binarization process. .

Other features of the present invention will be clarified by the description of the present specification and the accompanying drawings.

According to the present invention, it is possible to provide an inspection apparatus and an inspection method capable of accurately inspecting an abnormality in the puncture of a seal portion and an abnormality in a joint relating to an absorbent article such as a sanitary napkin.

1A is a plan view of the napkin 1, and FIGS. 1B and 1C are a BB sectional view and a CC sectional view, respectively, in FIG. 1A. 2A is an enlarged view of a portion II in FIG. 1A, and FIG. 2B is a cross-sectional view along line BB in FIG. 2A. 1 is a schematic side view of a production line for a napkin 1. FIG. It is an image figure of a plane image and inspection window W1. FIG. 5A is a planar image in the inspection window W1 before the first binarization process, and FIG. 5B is a binarized image generated by performing the first binarization process on the planar image. . It is an image figure of a plane image and inspection window W2. FIG. 7A is a planar image in the inspection window W2 before the second binarization process, and FIG. 7B is a binarized image generated by performing the second binarization process on the planar image. . It is a schematic diagram which shows a mode that the some test | inspection window W1, W1, W2 was set to the plane image. FIG. 9A is a schematic plan view of the semi-finished product 1a immediately before passing through the round seal processing apparatus 60, and FIG. 9B is a cross-sectional view taken along line BB in FIG. 9A. It is an image figure of a plane image and inspection window W3. FIG. 11A is a planar image in the inspection window W3 before the binarization processing, and FIG. 11B is a binarized image generated by performing the third binarization processing on the planar image. 11C is a binarized image generated by performing the fourth binarization process on the planar image, and FIG. 11D uses the binarized image of FIG. 11B and the binarized image of FIG. 11C. It is explanatory drawing of calculation of the value of the space | interval Ded made.

At least the following matters will become clear from the description of this specification and the accompanying drawings.

An inspection device for a seal part that joins a plurality of sheets laminated in a thickness direction constituting an absorbent article at an outer edge part of the absorbent article,
The seal portion is formed by pressing the plurality of stacked sheets in the thickness direction at the outer edge portion,
An imaging processing unit that captures an image of an area where the seal portion is formed on one side of the plurality of sheets and generates planar image data of the area as planar image data;
When generating the binarized image by binarizing the plane image data based on the first threshold value, the image specified by one of the binaries in the binarized image is displayed on the plane. A first binarization processing unit that performs binarization processing so as to include a region in which a perforated portion in a penetrating state is imaged in the thickness direction among imaging portions of the seal portion in the image;
When generating the binarized image by binarizing the planar image data based on the second threshold value different from the first threshold value, the binarized image is specified by one of the binary values. The binarization processing is performed so that the image to be processed includes an area where the abnormally bonded portions of the plurality of sheets in the unbonded state are imaged among the imaged portions of the seal portion in the planar image. A binarization processing unit;
Based on the binarized image generated by the first binarization processing unit, a first abnormality determination processing unit that determines the presence or absence of perforation abnormality;
And a second abnormality determination processing unit that determines whether or not there is a bonding abnormality based on the binarized image generated by the second binarization processing unit. Inspection equipment.

According to such an inspection device for a seal portion relating to an absorbent article, a binarized image specialized for determination of the presence / absence of perforation is generated based on the first threshold, and based on the second threshold Thus, a binarized image specialized for determining whether or not there is a bonding abnormality is generated. Then, based on each corresponding binarized image, the presence / absence of perforation abnormality and joining abnormality is determined. Therefore, it is possible to accurately inspect the hole perforation abnormality and the joining abnormality of the seal portion.

An inspection device for a seal portion according to such an absorbent article,
The plurality of sheets are conveyed in the conveyance direction in a continuous sheet state continuous in the conveyance direction,
The seal part is formed side by side in the transport direction in a predetermined formation pattern for each unit corresponding to the product of the absorbent article,
Before the plurality of sheets are divided into units corresponding to the products, it is preferable that the imaging processing unit images the area where the seal portion is formed.

According to such an inspection device for a seal portion relating to an absorbent article, since the region where the seal portion is formed is imaged in a continuous sheet state, the region can be stably imaged. As a result, based on the imaging portion of the seal portion in the planar image, it is possible to accurately inspect the seal portion for perforation and bonding abnormality.

An inspection device for a seal portion according to such an absorbent article,
The absorbent article includes a second portion in which a predetermined number of sheets of the plurality of sheets are stacked, and another sheet added to the predetermined number of sheets in the second portion and stacked. Having a first part,
The seal part has a first seal part formed on the first part, and a second seal part formed on the second part,
The first binarization processing unit sets a first inspection window that defines a target region of the binarization processing in the planar image to be inward, corresponding to an imaging portion of the first seal unit. ,
The second binarization processing unit sets a second inspection window that limits the binarization processing target area in the planar image to be inward corresponding to the imaging portion of the second seal unit. Is desirable.

According to such an inspection device for a seal part relating to an absorbent article, the number of sheets stacked differs between the first part and the second part, and as a result, the first part and the second part Even if the types of abnormalities that occur easily differ from each other, the binarized image required for inspection of perforated abnormalities and joint abnormalities while reducing the computational load of binarization processing Can be generated promptly. Details are as follows.

First, since the first portion where the first seal portion is formed has a larger number of sheets than the second portion where the second seal portion is formed, the first seal portion is likely to have a perforation abnormality, In addition, abnormal bonding is likely to occur in the second seal portion. Here, according to the inspection apparatus described above, the first binarization processing unit that generates the binarized image for the inspection of the puncture abnormality determines the target range of the binarization processing by the first inspection window. Set to the imaging part of the seal part. Therefore, the first binarization processing unit can quickly generate a binarized image for inspection of a holed abnormality while reducing the calculation load. In addition, the second binarization processing unit that generates a binarized image for inspection of the bonding abnormality sets the target range of the binarization processing in the imaging portion of the second seal unit by the second inspection window. Therefore, the second binarization processing unit can quickly generate a binarized image for inspection of a bonding abnormality while reducing the calculation load.

An inspection device for a seal portion according to such an absorbent article,
The absorbent article has a longitudinal direction, a width direction, and a thickness direction,
The absorbent article has a pair of wing portions extending in the width direction,
The wing part is joined by the seal part in a state in which several sheets of the plurality of sheets are laminated.
The second binarization processing unit defines a second inspection window that limits the binarization processing target area in the planar image inwardly in an imaging portion of the seal unit formed in the wing unit. It is desirable to set correspondingly.

According to such an inspection device for a seal portion relating to an absorbent article, it is possible to reliably detect an absorbent article that may cause a malfunction during use while reducing the calculation load of the second binarization processing unit. Become. Details are as follows.
The part with the highest handling frequency of the user when using the absorbent article is the wing part. Therefore, if there is an abnormality in bonding between the laminated sheets in the wing portion, it causes a mouth opening due to peeling or the like at the time of use starting from this, and as a result, it tends to cause a problem under the user.
In this regard, according to the above-described inspection apparatus, the second binarization processing unit sets the target range of the binarization processing in the imaging portion of the seal portion formed in the wing portion by the second inspection window. Therefore, the second binarization processing unit can reliably detect the absorbent article having the bonding abnormality in the wing portion in cooperation with the second abnormality determination processing unit while reducing the calculation load. As a result, it is possible to reliably detect an absorbent article that may cause a problem under the user.

An inspection device for a seal portion according to such an absorbent article,
The absorbent article has an absorbent body made of a liquid absorbent member between a pair of sheets among the plurality of sheets,
The plurality of sheets are conveyed in the conveyance direction in a continuous sheet state continuous in the conveyance direction, and the absorber is arranged intermittently in the conveyance direction,
The seal part has, as an end seal part, a portion located at the end in the transport direction rather than the absorber.
When generating the binarized image by binarizing the plane image data based on the third threshold value, the image specified by one of the binaries in the binarized image A third binarization processing unit that performs binarization processing so as to include an imaging portion of the end seal portion in the image;
When generating the binarized image by binarizing the plane image data based on the fourth threshold value, the image specified by one of the binaries in the binarized image A fourth binarization processing unit that performs binarization processing so as to include an imaging portion of an end of the absorber in the transport direction in the image;
Based on the binarized image generated by the third binarization processing unit and the binarized image generated by the fourth binarization processing unit, the absorber and the seal unit in the transport direction, It is desirable to include a third abnormality determination processing unit that determines whether or not the relative position is within the target range.

According to such an inspection apparatus for a seal portion related to an absorbent article, the third abnormality determination processing unit is based on a binarized image related to the end seal portion and a binarized image related to the end portion of the absorber. Thus, it is determined whether or not the relative position between the absorber and the seal portion in the transport direction is within the target range. Therefore, it is possible to detect whether there is an abnormality in the relative position between the absorber and the seal portion.

An inspection device for a seal portion according to such an absorbent article,
The determination of the presence or absence of perforation abnormality of the first abnormality determination processing unit indicates the size of the image specified by the one value among the binarized images generated by the first binarization processing unit. Based on the value,
When the value indicating the size of the image is larger than a predetermined first abnormality determination threshold, the first abnormality determination processing unit determines that there is a holed abnormality,
The determination of the presence or absence of a bonding abnormality in the second abnormality determination processing unit is performed on an image specified by a value that is not the one value among the binarized images generated by the second binarization processing unit. Based on the magnitude value,
When the value indicating the size of the image is smaller than a prescribed second abnormality determination threshold value, it is preferable that the second abnormality determination processing unit make the determination that there is a bonding abnormality.

According to such an inspection apparatus for a seal portion related to an absorbent article, the first abnormality determination processing unit indicates the size of the image including the imaging region of the perforated portion in the binarized image. When the value is larger than the prescribed first abnormality determination threshold, it is determined that there is a hole abnormality. Therefore, it is possible to accurately determine the presence or absence of perforation abnormality.
On the other hand, in the second abnormality determination processing unit, a value indicating the size of the image that does not include the imaging region of the abnormal joint portion in the binarized image, that is, the imaging region of the normal joint portion is included. When the value indicating the size of the image on the other side is smaller than the prescribed second abnormality determination threshold value, it is determined that there is a bonding abnormality. Therefore, it is possible to accurately determine whether or not there is a bonding abnormality.

Also,
A method for inspecting a seal part that joins a plurality of sheets laminated in a thickness direction constituting an absorbent article at an outer edge part of the absorbent article,
The seal portion is formed by pressing the plurality of stacked sheets in the thickness direction at the outer edge portion,
Imaging a region where the seal portion is formed in one side of the plurality of sheets and generating plane image data of the region as plane image data;
When generating the binarized image by binarizing the plane image data based on the first threshold value, the image specified by one of the binaries in the binarized image is displayed on the plane. Performing a first binarization process so as to include a region in which a perforated hole portion in the thickness direction is imaged among the imaging portions of the seal portion in the image;
When generating the binarized image by binarizing the planar image data based on the second threshold value different from the first threshold value, the binarized image is specified by one of the binary values. The second binarization process is performed so that the image to be processed includes an area in which the abnormal bonding portion in which the plurality of sheets are not bonded is imaged among the imaging portions of the seal portion in the planar image. To do and
Based on the binarized image generated by the first binarization process, determining whether there is a hole abnormality;
A method for inspecting a seal portion according to an absorbent article, comprising: determining whether or not there is a bonding abnormality based on a binarized image generated by the second binarization process.

According to the method for inspecting a seal portion related to such an absorbent article, a binarized image specialized for determination of presence / absence of perforation is generated based on the first threshold, and based on the second threshold Thus, a binarized image specialized for determining whether or not there is a bonding abnormality is generated. Then, based on each corresponding binarized image, the presence / absence of perforation abnormality and joining abnormality is determined. Therefore, it is possible to accurately inspect the hole perforation abnormality and the joining abnormality of the seal portion.

=== This Embodiment ===
The seal portion inspection apparatus 70 according to the absorbent article of the present embodiment is used in a production line for a sanitary napkin 1 as an example of an absorbent article.

1A is a plan view of the napkin 1, and FIGS. 1B and 1C are a BB sectional view and a CC sectional view in FIG. 1A, respectively. 2A is an enlarged view of a portion II in FIG. 1A, and FIG. 2B is a cross-sectional view taken along the line BB in FIG. 2A.

The napkin 1 is a substantially rectangular member in plan view having a longitudinal direction, a width direction, and a thickness direction. And as the component, the absorber 3 which absorbs and hold | maintains liquids, such as excretion liquid, and liquid-permeable surface sheets 2, such as a nonwoven fabric provided by covering this absorber 3 from a wearer's skin side, , A liquid-impermeable back sheet 4 such as a film provided so as to cover the absorbent body 3 from the non-skin side, and a pair of side sheets 6 and 6 disposed at each end in the width direction of the napkin 1, Have

The main body of the absorbent body 3 is formed by molding pulp fibers as a liquid absorbent member into a predetermined shape such as a substantially rectangular parallelepiped. In addition, the shape of the main body of the absorber 3 is not limited to a substantially rectangular parallelepiped, and may be formed into an arbitrary three-dimensional shape, for example. The absorbent body 3 is not limited to a simple pulp fiber molded body. For example, the molded body may be covered with tissue paper, or a superabsorbent polymer may be mixed therein.

The top sheet 2 receives the liquid excreted from the human body, quickly sucks it in the thickness direction, and guides it to the absorber 3. For example, a substantially rectangular sheet slightly larger than the planar shape of the absorber 3 is used. Is done. Non-woven fabrics such as air-through non-woven fabric and spunbonded non-woven fabric are used as the material of the surface sheet 2, and thermoplastic resin fibers such as polyethylene and polyethylene terephthalate are used as the constituent fibers of the non-woven fabric. In addition, the embossed groove | channel 2t is squeezed and formed in the thickness direction of the napkin 1 by the predetermined formation pattern on the surface of the surface sheet 2, and, thereby, the surface sheet 2 and the absorber 3 are joined and integrated.

The back sheet 4 is a leak-proof sheet that prevents leakage of liquid from the back side of the napkin 1, and its planar shape is a substantially rectangular shape that is sufficiently larger than the absorber 3. That is, the outer edge protrudes outward from the absorber 3 over the entire circumference. And in the state which mounted the absorber 3 on the surface side of this back surface sheet 4, it joins with the surface sheet 2 in the both ends of a longitudinal direction at least, Thereby, the absorber 3 is provided between the back surface sheet 4 and the surface sheet 2. Is retained.

Moreover, the back surface sheet 4 has portions 4w and 4w extending at both sides in the width direction at the position of the substantially central portion in the longitudinal direction. The portions 4w and 4w are bonded to portions 6w and 6w of side sheets 6 and 6 to be described later to form wing portions 1w and 1w. When attaching the napkin 1 to the inner surface of the underwear, the wing portions 1w, 1w are folded back and fixed to the outer surface of the underwear with an adhesive. As a material of the back sheet 4, for example, a film made of a thermoplastic resin such as polyethylene or polyethylene terephthalate is used.

The pair of side sheets 6 and 6 prevent liquid leakage from the respective end portions in the width direction of the napkin 1, and the side sheets 6 and 6 are respectively positioned on the respective end portions in the width direction while being surfaced. The sheet 2 and the back sheet 4 are covered with the sheets 2 and 4 while being covered from the front side. Specifically, the top sheet 2 is provided only at the center in the width direction so as to cover only the absorbent body 3 and is not provided at both ends in the width direction. Therefore, the back sheet 4 is the top sheet 2. It protrudes outward in the width direction. Therefore, the side sheets 6 and 6 are provided so as to cover both the protruding portions 4g and 4g of the back sheet 4 and the end portions 2e and 2e in the width direction of the top sheet 2 from the front side. For the material of the side sheet 6, for example, an appropriate nonwoven fabric such as an air-through nonwoven fabric or a spunbond nonwoven fabric formed of synthetic resin fibers is used.

The outer edge portion 1e of such a napkin 1 is formed with a seal portion 1s (see an annular region indicated by a dot pattern in FIG. 1A) in a substantially strip shape over the entire circumference. And the absorber 3 is located in the inner area | region which this seal | sticker part 1s surrounds. The seal portion 1s is formed by pressing the outer edge portion 1e in the thickness direction by a round seal device 60 described later. And the sheet | seats 2 and 4 laminated | stacked in the thickness direction in the outer edge part 1e, sheet | seats 4 and 6, and sheet | seats 2, 4 and 6 are welding-joined by this seal part 1s. For example, since only the back sheet 4 and the side sheet 6 are laminated on the end portions 1ee, 1ee in the width direction in the outer edge portion 1e, the seal portion 1s formed on the end portions 1ee, 1ee The back sheet 4 and the side sheet 6 are welded and joined. In addition, since only the back sheet 4 and the top sheet 2 are stacked on the center part 1ec in the width direction of the outer edge part 1e, the back surface is formed by the seal part 1s formed on the center part 1ec in the width direction. The sheet 4 and the surface sheet 2 are welded and joined. On the other hand, since the three parts of the back sheet 4, the top sheet 2, and the side sheet 6 are laminated on the boundary portion 1eb between the central portion 1ec and the end portion 1ee in the width direction, the boundary portion 1eb is formed. Three members of the back sheet 4, the top sheet 2, and the side sheet 6 are welded and joined by the seal portion 1 s.

FIG. 2A is an enlarged view of a part of the seal portion 1s, that is, an enlarged view of a portion II in FIG. 1A. FIG. 2B is a view taken along arrow BB in FIG. 2A. The seal portion 1s is composed of a plurality of concave portions 1d, 1d,. The sheets 2 and 4 are pressure-bonded at the bottom 1db of each recess 1d, and the sheets 2 and 4 are welded and joined together. Depending on the planar position of the napkin 1, the sheets 4 and 6 or the sheets 2, 4, and 6 are crimped at the bottom 1 db of each recess 1 d, and the sheets 4, 6, or the sheets The two, four, and six are welded together.

In the example of FIG. 2A, the shape of the bottom 1db of the recess 1d is a square. However, the shape is not limited to this, and may be a rectangle other than a square, a triangle, a pentagon or more, or a circle or an ellipse. good. In the example of FIG. 2A, the formation pattern of the recesses 1d, 1d... Is a lattice pattern, but is not limited to this, and may be a staggered pattern or other patterns. Needless to say, the concave portion 1d is a thin-walled portion that is thinner than the surrounding portion 1n where the concave portion 1d is not formed.

Further, the seal portion 1 s need not be formed continuously over the entire circumference of the outer edge portion 1 e of the napkin 1, and is selectively applied to an appropriate portion of the outer edge portion 1 e according to the product specifications of the napkin 1. It may be formed. That is, a plurality of groups of recesses in which a large number of recesses 1d, 1d... Are arranged in groups may be formed intermittently along the outer edge 1e. For example, the end portions 1ee and 1ee in the width direction of the napkin 1 may be formed only on the wing portions 1w and 1w (FIG. 1A).

FIG. 3 is a schematic side view of the production line for the napkin 1.
In the production line of the napkin 1, the semi-finished product 1a of the napkin 1 is transported at a predetermined transport speed along a predetermined transport direction by an appropriate transport mechanism 124. During such conveyance, various processes such as bonding, welding, pressing and punching of various parts are applied to the semi-finished product 1a, and the semi-finished product 1a changes its state each time. The napkin 1 in the state shown in FIG. 1A is generated. In this example, the semi-finished product 1a is conveyed in a so-called vertical flow. That is, the semi-finished product 1a is conveyed while aligning the direction corresponding to the longitudinal direction of the napkin 1 with the conveyance direction. As the transport mechanism 124 for transporting the semi-finished product 1a, for example, a suction belt conveyor having a suction holding function on a belt surface as a mounting surface, or a space between endless belts arranged in pairs above and below is a semi-finished product. A belt conveyor or a conveyance roller that is used as the conveyance path 1a is used.

The production line for the napkin 1 includes a fiber stacking step S10, a top sheet supply step S20, an embossed groove processing step S30, a side sheet supply step S40, a back sheet supply step S50, and a round seal processing step along the conveyance path of the semi-finished product 1a. S60, seal part inspection process S70, and parting process S80 are included.

Hereinafter, each of the steps S10 to S80 will be described. In the following description, a direction orthogonal to the conveyance direction of the semi-finished product 1a (in FIG. 3, a direction penetrating the paper surface) is also referred to as “CD direction”. The CD direction is parallel to the width direction of the semi-finished product 1a, and is also parallel to the width direction of the napkin 1.

In the first fiber stacking step S10, pulp fibers that are the main material of the absorbent body 3 are molded into a predetermined shape such as a substantially rectangular parallelepiped to form the absorbent body 3, and the molded absorbent body 3 is formed at a product pitch P1 in the transport direction. It is delivered onto a conveyor 124 which is a transport mechanism 124. And each absorber 3,3 ... is conveyed in the downstream of a conveyance direction in the state lined up intermittently in the conveyance direction. Such a molding process is performed by, for example, the rotary drum device 10. The rotary drum device 10 has a rotary drum 12 that is driven and rotated at a circumferential speed value substantially the same as the transport speed value of the conveyor 124 along the transport direction. A plurality of adsorption regions 14, 14,... For adsorbing and stacking pulp fibers are intermittently provided on the outer peripheral surface of the rotary drum 12 at a product pitch P1 in the circumferential direction. A duct 16 for supplying pulp fibers is disposed above the rotary drum 12. Therefore, when each adsorption area 14 of the rotary drum 12 passes through the position of this duct 16, pulp fibers are laminated in each adsorption area 14 to form the absorbent body 3, and then each adsorption area 14 is transferred to the conveyor. When passing through the position 124, the absorber 3 is delivered from each suction region 14 to the conveyor 124. Thereby, the absorbers 3, 3... Are thereafter sent downstream in the transport direction in a state of being aligned at the product pitch P1 in the transport direction.

In the next surface sheet supply step S20, the continuous sheet 2a of the surface sheet 2 (hereinafter also simply referred to as the surface sheet 2a) is passed through the upper supply roll 20, and the absorbent bodies 3, 3. .. Are continuously covered by the top sheet 2a from above.

In the next embossing groove processing step S30, the embossing device 30 squeezes the embossed grooves 2t on the upper surface from the upper surface corresponding to the surface of the surface sheet 2a, whereby the surface sheet 2a and the absorber 3 are Bonded and integrated.

In the next side sheet supply step S40, the continuous sheets 6a and 6a of the pair of side sheets 6 and 6 (hereinafter also simply referred to as side sheets 6a and 6a) are respectively provided in the semi-finished product 1a via the upper supply roll 40. The sheet is supplied to each end portion in the CD direction of the surface sheet 2a, and thereby the side sheets 6a and 6a are bonded to each end portion.

In the next back sheet supply step S50, a continuous sheet 4a of the back sheet 4 (hereinafter also simply referred to as a back sheet 4a) is supplied to the semi-finished product 1a via the lower supply roll 50, and the back sheet 4a From the side, it is bonded to the top sheet 2a and the pair of side sheets 6a, 6a. Thereby, the semifinished product 1a will be in the state by which the absorber 3 was interposed between the surface sheet 2a and a pair of side sheet 6a, 6a, and the back surface sheet 4a.

In the next round seal processing step S60, a seal portion 1s is formed at a portion corresponding to the outer edge portion 1e of the napkin 1 in the semi-finished product 1a. Are welded and joined at a portion corresponding to the outer edge portion 1e. The forming process of the seal portion 1s is performed by the round seal processing apparatus 60. The round seal processing device 60 includes a pair of upper and lower rolls 60a and 60b that are driven and rotated around a rotation axis C60 along the CD direction with their outer peripheral surfaces facing each other. Here, the upper roll 60a has a convex portion (not shown) on the outer peripheral surface, and the lower roll 60b has a smooth outer peripheral surface to receive the convex portion. Moreover, the convex part protrudes from the outer peripheral surface of the roll 60a in the shape corresponding to the formation pattern of the above-mentioned seal part 1s. Specifically, the convex portion includes a rib portion (not shown) having a shape corresponding to the outer edge portion 1e of the napkin 1, and a plurality of island-like convex portions (not shown) discretely provided on the top surface of the rib portion. Have. Therefore, when the semi-finished product 1a passes through the roll gap between these rolls 60a, 60b, the portion corresponding to the outer edge portion 1e of the napkin 1 in the semi-finished product 1a is a plurality of island-shaped convex portions and the outer peripheral surface of the roll 60b. Thus, a seal portion 1s composed of a plurality of recesses 1d, 1d... Is pressed at a portion corresponding to the outer edge portion 1e of the napkin 1 in the semi-finished product 1a.

In addition, this round seal processing apparatus 60 is comprised so that the magnitude | size of a press load can be adjusted. That is, at least one 60a (60b) of the roll 60a or the roll 60b is supported at both ends in the CD direction of the roll 60a (60b) by an actuator (not shown) such as an appropriate hydraulic cylinder so as to be movable up and down. The controller 64 controls the actuator. Therefore, the control part 64 can adjust a press load by opening and closing the roll gap | interval between the roll 60a and the roll 60b via an actuator. For example, when the pressing load is changed in the decreasing direction, the roll gap is operated in the opening direction, and when the pressing load is changed in the increasing direction, the roll gap is operated in the closing direction.

In the seal portion inspection step S70, the seal portion 1s of the semi-finished product 1a is inspected for the presence of a perforation abnormality and a joining abnormality. This inspection is performed by the seal portion inspection device 70. The inspection device 70 will be described later.

In the dividing step S80, the semi-finished product 1a continuous in the conveying direction is divided into product units, whereby a single-cut napkin 1 is generated. This cutting process is performed by the die cutter device 80. The die cutter device 80 has a pair of upper and lower rolls 80a and 80b that are driven and rotated around a rotation axis C80 along the CD direction with their outer peripheral surfaces facing each other. The upper roll 80a is a cutter roll 80a having a cutter blade (not shown) on the outer peripheral surface, and the lower roll 80b is an anvil roll 80b that receives the cutter blade on a smooth outer peripheral surface. The cutter blade protrudes from the outer peripheral surface of the cutter roll 80a in a shape corresponding to the outer shape of the napkin 1 described above. Therefore, when the semi-finished product 1a passes through the gap between the rolls 80a and 80b, the napkin 1 is punched out from the semi-finished product 1a.

Then, the napkins 1, 1... Generated through the above steps S10 to S80 are packed in a predetermined number, packed and shipped in a unit of stack.

The operations of the steps S10 to S80 of the production line are performed in conjunction with each other by a synchronization signal. The synchronization signal is, for example, a rotation angle signal in which rotation angle values of 0 ° to 360 ° are allocated in proportion to the conveyance amount, with the conveyance amount corresponding to one napkin 1 as a unit conveyance amount. That is, when a semi-finished product 1a having a length corresponding to one napkin 1 (the same value as the product pitch P1) is conveyed, a rotation angle value from 0 ° to 360 ° is output, and the one-minute conveyance is performed. In each case, the output of the rotation angle value from 0 ° to 360 ° is repeated periodically. Then, this synchronization signal is transmitted to the amplifier of each servo motor that is a drive source for the operations of steps S10 to S80, and each servo motor performs position control based on the synchronization signal, thereby processing the semi-finished product 1a. Each target position to be processed is processed.

Here, the synchronization signal is generated by a rotary encoder provided on the cutter roll 80a of the die cutter device 80. That is, the synchronization signal is generated based on the rotation operation of the cutter roll 80a. Thus, the rotary drum 12 of the rotary drum device 10 and the roll 60a of the round seal processing device 60 rotate in synchronization with and in conjunction with the rotation operation of the cutter roll 80a of the die cutter device 80. ing. Therefore, on the semi-finished product 1a, the position of the outline (punching position) of the napkin 1 punched and formed by the cutter roll 80a is a reference for the processing position.

By the way, in the above-described round seal processing apparatus 60, the seal portion 1s is basically formed with a prescribed pressing load, but the basis weight variation of the top sheet 2a and the basis weight variation of the back sheet 4a, Due to variations in the basis weight of the side sheets 6a, 6a, etc., at a certain ratio, the depressions 1d, 1d,... In the recesses 1d, 1d,... Of the seal portion 1s that should manage the joining of the sheets 2, 4, 6 to each other, the pressing may be insufficient, and an unjoined joining abnormality may occur. Furthermore, recently, since the number of products in which the number of stacked sheets 2, 4 and 6 partially differs at the outer edge portion 1e of the napkin 1, the round seal processing apparatus 60 stacks these sheets 2, 4 and 6 together. Different parts must be pinched with the same size of the gap between the rolls, and this may promote the occurrence of the above-mentioned abnormality. For example, also in the case of the napkin 1 of the present embodiment, as shown in FIG. 1A and FIG. 1B, a two-layer structure portion 1ec (or 1ee) in which the back sheet 4 and the top sheet 2 (or side sheet 6) overlap each other, In addition to this, a portion 1eb having a three-layer structure in which the side sheets 6 are further overlapped is present on the outer edge portion 1e, and the above-described abnormality is likely to occur.

Therefore, in the present embodiment, as shown in FIG. 3, the seal portion inspection device 70 is provided between the round seal processing step S <b> 60 and the dividing step S <b> 80 in order to accurately inspect a hole abnormality or joining abnormality of the seal portion 1 s. It is arranged. Hereinafter, the inspection apparatus 70 will be described.

In addition, the semi-finished product 1a at the time of sending to this inspection apparatus 70 is between the surface sheet 2a of the continuous sheet state in which the side sheets 6a and 6a of the continuous sheet state were affixed, and the back surface sheet 4a of the continuous sheet state. A plurality of absorbent bodies 3, 3... Intermittently arranged in the conveying direction are interposed, and a sheet is provided at a certain portion by a seal portion 1 s formed at a portion corresponding to the outer edge portion 1 e of the napkin 1. 2a and 4a are in a state where the sheets 4a and 6a are joined together at a certain part, and the sheets 2a, 4a and 6a are joined together at a part. And this semi-finished product 1a is a continuous body of the undivided state in the unit still equivalent to the product of the napkin 1. Therefore, hereinafter, for convenience of explanation, the unit 1b corresponding to the product of the napkin 1 in the semi-finished product 1a is referred to as “unit semi-finished product 1b”. Incidentally, this unit semi-finished product 1b corresponds to the “unit corresponding to the product of the absorbent article” according to the claims.

As shown in FIG. 3, the inspection device 70 is arranged adjacent to the immediate downstream side of the round seal processing step S60. In this inspection apparatus 70, for each unit semi-finished product 1b, which is a unit corresponding to the product 1 in the semi-finished product 1a, the perforation abnormality and the joining abnormality of the seal portion 1s are inspected. If it is determined that the unit semi-finished product 1b is perforated or bonded abnormally, the determination result is transmitted to the control unit 64 of the round seal processing device 60 for use in opening / closing control of the roll gap. .

The inspection apparatus 70 includes a camera 72 as an imaging processing unit provided at a predetermined position on the conveyance path of the semi-finished product 1a, and an illumination member 74 disposed at a position sandwiching the conveyance path from above and below with the camera 72. And an image processing unit 76 for determining the presence or absence of perforation abnormality and joining abnormality of the seal part 1s.

The camera 72 is, for example, a CCD (charge coupled device) camera. And it arrange | positions facing the surface by the side of the surface sheet 2a of the semifinished product 1a (equivalent to "one side of a some sheet | seat"), and, thereby, the surface sheet 2a side of the semifinished product 1a which passes the imaging position PS The plane is imaged and plane image data is generated. The imaging operation is performed based on the synchronization signal, whereby the unit semi-finished product 1b is imaged so that the plane center thereof is substantially aligned with the plane center of the plane image. Here, as described above, the synchronization signal is a rotation angle value from 0 ° to 360 °, where the conveyance amount corresponding to one unit semi-finished product 1b is a unit conveyance amount (the same value as the product pitch P1). , A rotation angle signal assigned in proportion to the transport amount. Therefore, as described above, the phase of the synchronization signal corresponding to the imaging timing such that the plane center of the unit semi-finished product 1b matches the plane center of the plane image is found as a predetermined rotation angle value, and the predetermined rotation corresponding to the phase is detected. If it is set in advance to perform the imaging operation with the angle value, the plane center of the unit semi-finished product 1b and the planar image of all the unit semi-finished products 1b that pass through the imaging position PS after that are set as described above. Imaging can be performed so that the plane centers are aligned.

And the camera 72 adjusted to such an imaging timing repeats imaging for every unit semi-finished product 1b, and produces | generates the data of the imaged planar image as planar image data for every imaging. Then, the plane image data is transmitted to the image processing unit 76 every time it is generated. Then, the image processing unit 76 determines for each unit semi-finished product 1b whether or not there is a holed hole abnormality and a bonding abnormality related to the seal part 1s based on the planar image data. As a result, all the napkins 1 are inspected. However, the present invention is not limited to this, and for example, images may be taken every several unit semi-finished products 1b.

The semi-finished product 1a at the time of imaging is in a continuous state before being divided into product units, that is, the semi-finished product 1a is imaged in a continuous state that is continuous in the transport direction. Therefore, it is possible to stably image the region where the seal portion 1s is formed.

The illumination member 74 is an appropriate light such as a white LED light or a fluorescent lamp, and the type of the light source is appropriately selected according to the imaging situation on the spot. Further, as described above, the arrangement position of the illumination member 74 is set to a position where the semi-finished product 1a is sandwiched between the camera 72 from above and below, so that the camera 72 is transmitted through the semi-finished product 1a in the thickness direction. Imaging is performed by receiving light.

The image processing unit 76 includes a suitable computer as a main body and includes a processor and a memory. The processor reads out and executes various processing programs stored in advance in the memory, thereby performing various arithmetic processes.
That is, in the present embodiment, the first binarization processing program for generating a binarized image for perforation abnormality inspection from planar image data and the planar image data are joined in the memory. A second binarization processing program for generating a binarized image for abnormality inspection is stored in advance. In addition, a first abnormality determination processing program for determining the presence or absence of a perforation abnormality in the seal portion 1s based on the binarized image for the perforation abnormality inspection, and the binarized image for the joint abnormality inspection A second abnormality determination processing program for determining whether there is a bonding abnormality in the seal portion 1s based on the second abnormality determination processing program is also stored in advance.

Therefore, when the processor reads and executes these programs as appropriate, the image processing unit 76 functions as a first binarization processing unit that generates a binarized image for perforation abnormality inspection from planar image data. Also, it functions as a first abnormality determination processing unit that determines whether or not there is a perforation abnormality in the seal portion 1s based on the binarized image for perforation abnormality inspection. While functioning as a second binarization processing unit that generates a binarized image, it also serves as a second abnormality determination processing unit that determines the presence or absence of a bonding abnormality of the seal unit 1s based on the binarized image for inspection of the bonding abnormality. Function. Hereinafter, the first binarization process (corresponding to the first binarization process), the first abnormality determination process, the second binarization process (corresponding to the second binarization process), and the second abnormality determination process Will be described.

<<<< About the 1st binarization process and 1st abnormality determination process which are related to a perforation abnormality inspection >>
First, before describing the first binarization process, a planar image and planar image data will be described with reference to FIG.

FIG. 4 is an image diagram of a planar image. In FIG. 4, a dot pattern is given to the imaging part A1s of the seal part 1s. The planar image is captured, for example, with the CD direction as the X direction and the transport direction as the Y direction, and the planar image is captured as an entire image of the unit semi-finished product 1b.

Such a planar image is an aggregate of a large number of pixels arranged in a grid at a predetermined pitch based on a predetermined resolution in both the X direction and the Y direction. In other words, the planar image is composed of a plurality of pixels arranged in a straight line in the X direction at a predetermined pitch and arranged in a plurality of rows at a predetermined pitch in the Y direction. The plane image data has color information corresponding to each pixel. For example, when the plane image data is grayscale, each pixel has only brightness as color information. In that case, each pixel corresponding to the region with high translucency in the unit semi-finished product 1b becomes bright, so that the brightness of the pixel is high, but on the other hand, in the region with low translucency. Since each corresponding pixel becomes dark, the brightness of the pixel is a low value.

Here, when the concave portion 1d of the seal portion 1s is normally formed without penetrating a hole, the translucency of the concave portion 1d is lower than that when the hole is perforated. is there. Therefore, by paying attention to pixels whose brightness is equal to or higher than a predetermined value, it is possible to specify the pixels in the region Ah (FIG. 5A) where the penetrating hole portion h is imaged on the planar image in FIG. 4. Incidentally, since the recess-unformed portion 1n, which is a portion 1n between the recess 1d and the recess 1d shown in FIG. 2, is a thicker portion than the recess 1d, its translucency is lower than that of the recess 1d. The brightness of the pixel corresponding to the recess-unformed portion 1n is lower than the brightness of the pixel corresponding to the recess 1d. Furthermore, since the portion 1r where the topsheet 2a, the absorber 3 and the backsheet 4a in FIG. 2 overlap is a portion thicker than the seal portion 1s, its translucency is higher than that of the seal portion 1s. As a result, the brightness of the pixel corresponding to the portion 1r is lower than the brightness of the pixel corresponding to the seal portion 1s. In the following description, it is assumed that the planar image data is grayscale data.

In the first binarization process, in order to reduce the calculation load of the image processing unit 76, the target range of the binarization process in the planar image is limited. That is, in the first binarization process, as shown in FIG. 4, an inspection window W1 (corresponding to the first inspection window) is set, and as a result, only a region surrounded by the inspection window W1 in the planar image is converted into two. The target of the value processing. Details of the inspection window W1 will be described later.

Further, in the first binarization process, a predetermined first binarization threshold (corresponding to the first threshold) is used. This first binarization threshold is set to a value between the brightness of the pixel corresponding to the normally formed recess 1d and the brightness of the pixel corresponding to the perforated portion h, and is stored in advance in the memory. ing.

Then, among the pixels in the inspection window W1 in FIG. 5A, a pixel having a lightness equal to or higher than the first binarization threshold is selected as one of the binary values (for example, 0 and 1) in the binarized image in FIG. 5B. The white image specified by the value “1” is allocated to the white image, and the pixels having the brightness less than the first binarization threshold are allocated to the black image specified by the other value “0”. This is performed for all the pixels in the inspection window W1 of FIG. 5A. As a result, the areas Ah, Ah... Where the perforated portion h is imaged among the pixels in the inspection window W1 as shown in FIG. 5A are included in the white image in the binarized image as shown in FIG. 5B. The other parts are processed so as to be included in the black image. That is, the binarized image of FIG. 5B is generated by binarizing the planar image data using the inspection window W1 shown in FIG. 5A. In FIG. 5B, the portion A1s corresponding to the seal portion 1s in the binarized image is virtually indicated by a two-dot chain line, but naturally such a line does not exist in the binarized image.

Then, the image processing unit 76 proceeds to the first abnormality determination process. In the first abnormality determination process, first, the area of the white image on the binarized image in FIG. 5B is obtained. Here, the planar size of the pixel is known in advance based on each resolution in the XY directions. Therefore, the area of the white image is calculated by multiplying the planar size of this pixel by the number of pixels that is the number of pixels allocated to the white image. Incidentally, the area of the white image corresponds to the “value indicating the size of the image specified by the one value among the binarized images generated by the first binarization processing unit” according to the claims. To do.

Next, the image processing unit 76 compares the calculated area of the white image with the first abnormality determination threshold value stored in advance in the memory. When the area of the white image is equal to or smaller than the first abnormality determination threshold, the image processing unit 76 determines that “the size of the holed portion h is sufficiently small and no holey abnormality has occurred”. On the other hand, if it is larger than the first abnormality determination threshold, it is determined that “the holed portion h is large and a holey abnormality has occurred”. Then, the determination result of “abnormality in perforation” is transmitted to the control unit 64 of the round seal processing apparatus 60. Then, the control part 64 which received this opens the roll gap | interval between the roll 60a and the roll 60b so that it may become only a predetermined value larger than a present value, and changes a pressing load to a reduction | decrease direction. Thereby, the perforated portion h of the unit semi-finished product 1b passing through the round seal processing apparatus 60 is reduced thereafter, and the perforation abnormality can be suppressed.

Note that the above-described first abnormality determination threshold is a fixed value stored in advance in the memory. And this 1st abnormality determination threshold value is calculated | required by the experimental method in the following production lines, for example. First, a plurality of samples of the unit semi-finished product 1b in which the concave portions 1d, 1d... Of the seal portion 1s are normally formed are prepared. Next, these samples are imaged by the CCD camera 72 of the inspection apparatus 70, the first binarization process is performed for each sample, and the area of the white image in the inspection window W1 is obtained for each sample. Then, the average value and standard deviation σ of the area of the white image of all the samples are calculated, and a value larger by 2σ than the average value is used as the first abnormality determination threshold value. Incidentally, when the inspection apparatus 70 frequently determines “abnormal”, the first abnormality determination threshold value may be changed to a larger value. In some cases, the memory of the image processing unit 76 has a value that is larger than the first abnormality determination threshold (for example, a value that is larger by 3σ than the above-described average value) as an upper limit in advance, and When the area of the above-mentioned white image is larger than the upper limit value, the image processing unit 76 associates that the product is a defective product, for example, by giving perforated defect information to the unit semi-finished product 1b corresponding to the planar image. And you may make it use for the separation process of the quality goods and inferior goods in a lower process.

Here, the inspection window W1 will be described with reference to FIG. As described above, the inspection window W1 is a tool that divides and limits an area to be referred to in the planar image at the time of binarization processing, that is, belongs to the inspection window W1 at the time of binarization processing. It is possible to refer only to pixels and not refer to pixels outside the inspection window W1.

The inspection window W1 is set to an imaging portion at a planar position where a hole is likely to be generated, among the imaging portions A1s of the seal portion 1s in the planar image. Such a plane position is basically a plane position where the pressing pressure (pressing load per unit area (N / m ² )) at the time of pressure bonding tends to be high. Specifically, as an example of the former, there is a downstream end seal portion 1sed that is a downstream end portion 1sed in the transport direction in the seal portion 1s, that is, the end seal portion 1sed includes the round seal processing device 60. The impact pressure is likely to act upon the biting into the roll gap, and the pressing pressure tends to increase. For this reason, in the example of FIG. 4, the inspection window W1 is set for the imaging portion A1sed of the end seal portion 1sed. However, the present invention is not limited to this and may be set to a plane position other than this.

It should be noted that such reference of pixels limited to the inspection window W1 is realized as follows, for example. First, XY coordinates are assigned to each pixel of the planar image, and these XY coordinates are recorded in the memory. Further, the image processing unit 76 is configured to be able to access color information of pixels belonging to the inspection window W1 by designating the XY coordinates. Therefore, if the data of the XY coordinates of the pixel to be positioned in the inspection window W1 is recorded in the memory in advance, it is possible to realize reference of pixels limited to the above-described inspection window W1.

<<< Second Binarization Processing and Second Abnormality Determination Processing Related to Bonding Abnormality Inspection >>>
The image processing unit 76 performs the second binarization process and the second abnormality determination process related to the joint abnormality inspection substantially simultaneously with the first binarization process and the first abnormality determination process. The planar image data used for the second binarization process is the same as that used in the first binarization process.

Here, when the top sheet 2a and the absorbent body 3 are not joined in the recess 1d of the seal portion 1s, the unjoined recess 1dn is thicker than the normal recess 1d. The translucency is lower than that of the normal recess 1d. Therefore, by paying attention to pixels whose brightness is equal to or higher than a predetermined value, it is possible to specify the pixels in the area A1d where the normal recess 1d is imaged on the planar image in FIG.

Also in this second binarization process, the target range of the binarization process in the planar image is limited for the purpose of reducing the calculation load of the image processing unit 76. That is, in the second binarization process, the inspection windows W2 and W2 (corresponding to the second inspection window) are set as shown in FIG. 6, and are thereby surrounded by the inspection windows W2 and W2 in the planar image. Only the area is the target of the binarization process. The inspection window W2 is set so as to correspond to a planar position that leads to a serious problem particularly when a bonding abnormality occurs in the seal portion 1s. As an example of this planar position, the wing parts 1w and 1w of the napkin 1 are mentioned. That is, since the wing parts 1w and 1w are parts which the user of the napkin 1 handles at the time of wearing, when the side sheet 6 and the back sheet 4 are peeled off in the wing parts 1w and 1w, they are in an open state. It becomes difficult to handle. Therefore, in this embodiment, the inspection window W2 is set for each wing portion 1w with respect to the imaging portion A1s of the seal portion 1s formed in the wing portions 1w and 1w. That is, since there are two wing portions 1w and 1w, two inspection windows W2 and W2 are also set. However, the set number and set position of the inspection window W2 are not limited to this, and the set number may be one, or the set position may be a plane position other than the wing portion 1w.

Also, in the second binarization process, a predetermined second binarization threshold (corresponding to the second threshold) is used. This second binarization threshold is set to a value between the brightness of the pixel corresponding to the normally formed recess 1d and the brightness of the pixel corresponding to the unjoined recess 1dn, and is stored in advance in the memory. Stored. Incidentally, the second binarization threshold is set to a value smaller than the first binarization threshold, as is apparent from the above definition. That is, in order to specialize in the inspection of the bonding abnormality, it is set to a value different from the above-described first binarization threshold value specializing in the inspection of the hole abnormality.

Then, among the pixels in the inspection window W2 in FIG. 7A, a pixel having a lightness equal to or higher than the second binarization threshold is selected as one of the binary values (for example, 0 and 1) in the binarized image in FIG. 7B. The white image specified by the value “1” is allocated to the white image, and the pixels having the brightness less than the second binarization threshold are allocated to the black image specified by the other value “0”. This is performed for all the pixels in the inspection window W2 in FIG. 7A. As a result, as shown in FIG. 7A, among the pixels in the inspection window W2, areas A1d, A1d... In which normal concave portions 1d, 1d. Are processed so as to be included in the black image in the binarized image. Areas A1dn, A1dn... In which the unbonded recesses 1dn, 1dn. The That is, the binarized image of FIG. 7B is generated by binarizing the planar image data using the inspection window W2 shown in FIG. 7A. Note that such binarization processing is performed for each of the inspection windows W2 and W2 in FIG. 6, and in this embodiment, two binarized images are generated as shown in FIG. 7B. Incidentally, in FIG. 7B, the portion A1s corresponding to the seal portion 1s in the binarized image is indicated by a two-dot chain line, but naturally such a line does not exist in the binarized image.

Then, the image processing unit 76 proceeds to the second abnormality determination process. In the second abnormality determination process, first, the area of the white image on the binarized image is obtained for each binarized image in FIG. 7B. Here, the planar size of the pixel is known in advance based on each resolution in the XY directions. Therefore, the area of the white image is calculated for each binarized image by multiplying the planar size of this pixel by the number of pixels that is the number of pixels allocated to the white image. Incidentally, the area of the white image is the size of the image specified by the value which is not the one of the two values among the binarized images generated by the second binarization processing unit according to the claims. Corresponds to “value shown”.

Next, the image processing unit 76 compares the area of the white image of each binarized image with the second abnormality determination threshold value stored in advance in the memory. If the area of any white image is equal to or greater than the second abnormality determination threshold, the image processing unit 76 determines that “the normal concave portion 1d is sufficiently large, so that no bonding abnormality has occurred”. On the other hand, if the area of the white image is smaller than the second abnormality determination threshold value even in one of the two binarized images, it is determined that “the normal concave portion 1d is small and a bonding abnormality has occurred”. To do. Then, the determination result of “abnormal joining” is transmitted to the control unit 64 of the round seal processing apparatus 60. Then, the control part 64 which received this closes the roll gap | interval between the roll 60a and the roll 60b so that it may become only a regulation value smaller than a present value, and changes a press load to an increase direction. Thereby, unjoined part 1dn of unit semi-finished product 1b which passes round seal processing device 60 after this is shrunk, and it can control joining abnormalities.

Note that the second abnormality determination threshold is a fixed value stored in advance in the memory. The second abnormality determination threshold value is obtained, for example, by an experimental method on the following production line. First, a plurality of samples of the unit semi-finished product 1b in which the concave portions 1d, 1d... Of the seal portion 1s are normally formed are prepared. Next, these samples are imaged by the CCD camera 72 of the inspection apparatus 70, the second binarization process is performed for each sample, and the area of the white image in the inspection window W2 is obtained for each sample. Then, the average value and standard deviation σ of the areas of the white images of all the samples are calculated, and a value smaller by 2σ than the average value is used as the second abnormality determination threshold value. Incidentally, when the inspection apparatus 70 frequently determines “abnormal”, the second abnormality determination threshold value may be changed to a smaller value. In some cases, the memory of the image processing unit 76 has a value lower than the second abnormality determination threshold (for example, a value smaller by 3σ than the above-described average value) as a lower limit in advance, and When the area of the white image is smaller than the lower limit value even in one of the two binarized images, the image processing unit 76 displays the bonding failure information for the unit semi-finished product 1b corresponding to the planar image. It is also possible to associate the product with a defective product such as by giving it to a separation process between a non-defective product and a defective product in a lower process.

In the present embodiment, the first abnormality determination process and the second abnormality determination process determine whether or not there is an abnormality independently of each other. There are cases in which both determination results of abnormal bonding are output. In that case, the change direction of the pressing load of the round seal processing device 60 is opposite to each other in the decreasing direction and the increasing direction, but in this case, either of the determination results is different. The priority order may be set in advance so as to give priority to the control of the pressing load of the round seal processing apparatus 60. For example, when both determination results are output, the determination result of the perforated abnormality is given priority over the abnormality in joining, and the pressing load may be set to change in the decreasing direction.

Incidentally, in the above-described embodiment, as shown in FIG. 4, one inspection window W1 is set for the imaging portion A1sed of the end seal portion 1sed, but preferably, the imaging portion A1sed is divided into a plurality of parts. The inspection windows W1 and W2 may be set. 8 to 9B are explanatory diagrams thereof. FIG. 8 is a schematic diagram illustrating a state in which a plurality of inspection windows W1, W1, and W2 are set as a planar image. 9A is a schematic plan view of the semi-finished product 1a immediately before passing through the round seal processing apparatus 60, and FIG. 9B is a cross-sectional view taken along line BB in FIG. 9A.

In the example of FIG. 8, the imaging portion A1sed of the end seal portion 1sed is divided into three regions A1sed2, A1sed1, and A1sed1 in the X direction (CD direction and width direction). Of these three regions, a center region A1sed2 located in the center in the X direction is set with an inspection window W2 for inspecting a bonding abnormality, while a pair of end regions A1sed1, located on both sides of the center region A1sed2. A1sed1 is set with inspection windows W1 and W1 for a holed abnormality inspection, respectively. The reason for this is that in the end seal portion 1sed, the number of stacked sheets 2a, 4a, 6a differs depending on the position in the CD direction, and as a result, the end seal portion 1sed is perforated. This is because there is a portion 1sed2 where an abnormality is likely to occur and a portion 1sed1 where an abnormality is likely to occur.

More specifically, first, as shown in FIGS. 9A and 9B, on the conveyance path of the production line, a portion 1a2 (second) in which a top sheet 2a and a back sheet 4a are laminated in the center in the CD direction (second). Part of the two-layer structure 1a2 and the three-layer structure parts 1a1 and 1a1 (the first layer) in which the side sheet 6a is further laminated in addition to the top sheet 2a and the back sheet 4a, respectively. Is equivalent to one part). Further, the size of the roll gap of the round seal processing apparatus 60 in which the seal portion 1s is to be formed is set to be substantially constant over the CD direction. That is, the interval between the above-described convex portion on the outer peripheral surface of the upper roll 60a of the apparatus 60 and the outer peripheral surface of the lower roll 60b is substantially constant over the CD direction. Therefore, the pressing load concentrates on the three-layer structure portions 1a1 and 1a1 from the convex portion of the upper roll 60a and the lower roll 60b to increase the load. The pressing load of 1a2 becomes small. As a result, perforation abnormalities are likely to occur in the end portions 1sed1, 1sed1 (corresponding to the first seal portion) in the CD direction of the end seal portion 1sed, and the center portion 1sed2 (second seal) of the end seal portion 1sed is likely to occur. (Corresponding to the portion) is likely to cause abnormal bonding.

In order to reliably detect the occurrence of these abnormalities, as described above, the inspection window W2 is set for the central region A1sed2 in the imaging part A1sed of the end seal part 1sed to inspect the bonding abnormality. The second binarization process and the second abnormality determination process are performed on the center area A1sed2, and the end area A1sed1 and A1sed1 in the imaging part A1sed of the end seal part 1sed are perforated abnormally. It is preferable to set the inspection window W1 to be inspected and perform the first binarization process and the first abnormality determination process for each of the end regions A1sed1 and A1sed1.

In the above description, the central region A1sed2 and the end regions A1sed1 and A1sed1 in the imaging portion A1sed of the end seal portion 1sed are illustrated as the regions where the separate inspection windows W1 and W2 are to be set, but the present invention is not limited to this. is not. That is, in the semi-finished product 1a, if the portions 1a1 and 1a2 in which the number of stacked sheets 2a, 4a, and 6a is different from each other in the portion where the seal portion 1s is to be formed, separate inspection windows are provided for the portions 1a1 and 1a2. W1 and W2 may be set. More precisely: The seal portion 1s is formed on both the first portion 1a1 and the second portion 1a2 of the semi-finished product 1a, and the first portion 1a1 adds another sheet 6a to the second portion 1a2. In the case of being laminated, the first portion 1a1 is preferably set with an inspection window W1 for hole abnormality inspection, and the second portion 1a2 is set with an inspection window W2 for bonding abnormality inspection. .

Further, as shown in FIGS. 1A to 1C, in the napkin 1 of the present embodiment, a pair of three-dimensional gathers (also referred to as leak-proof cuffs) that prevent lateral leakage are provided on both sides of the absorbent body 3 in the width direction. In the case of the napkin 1 having the three-dimensional gather, the end seal portion 1sed generally does not have an end portion in the longitudinal direction of the three-dimensional gather. At each end in the width direction of the portion 1sed, the end in the longitudinal direction of the three-dimensional gather sheet constituting the three-dimensional gather is fixed in a folded state. Therefore, each end portion in the width direction of the end seal portion 1sed is a portion having a number of layers equal to or greater than the three-layer structure. It is a thick part. Accordingly, in this case as well, as described above, the imaging portion A1sed of the end seal portion 1sed is divided into a plurality of regions A1sed2, A1sed1, and A1sed1, and the inspection windows W2, W1, and A1sed1 are associated with the regions A1sed2, A1sed1, and A1sed1. It is good to set W1.

<<<< About Inspection of Relative Position of Absorbent Body 3 and Seal Part 1s in the Conveying Direction >>>>
As described above, the inspection of the sealing portion 1s perforation abnormality and the joining abnormality performed by the inspection device 70 has been described. You may make it test | inspect for the presence or absence of abnormality of a relative position with 1s.

First, explain why such an inspection is necessary. As described above, the devices 10, 20,..., 80 in the production line of FIG. 3 including the transport mechanism 124 operate in conjunction with each other according to the synchronization signal. And this synchronizing signal is produced | generated by the rotary encoder provided in the die cutter apparatus 80 which is an apparatus used as the reference | standard of a manufacturing line. That is, in the present embodiment, the synchronization signal is generated based on the rotation operation of the cutter roll 80a that punches and forms the napkin 1.

By the way, even if it is a case where each apparatus 10,20 ..., 80 is interlock | cooperated based on such a synchronizing signal, the fluctuation | variation in lot units, such as the basic weight of the absorber 3, a moisture content, or a roll shape Variations in the winding diameter of various sheets such as the surface sheet 2a fed out from the surface sheet roll in the wound state are combined, thereby forming the absorbent body 3 in the conveying direction of the semi-finished product 1a with a large period. The position may fluctuate. That is, the actual formation position of the absorber 3 is shifted in the order of several millimeters upstream and downstream in the transport direction from the target position with a very large period corresponding to several hundred to several thousand pieces of the unit semi-finished product 1b. A phenomenon may occur.

Even when the round seal processing device 60 correctly forms the seal portion 1s based on the synchronization signal when the phenomenon occurs, the absorber 3 is displaced from the target position in the transport direction. The relative position between the body 3 and the seal portion 1s is deviated from the target relative position. As a result, even if the product does not immediately become a defective product, the seal portion 1s is attached to the absorber 3 in the napkin 1. On the other hand, it looks bad, such as being misaligned, which may lead to a deterioration of the product image.

Therefore, it is necessary to inspect whether there is an abnormality in the relative position between the absorber 3 and the seal portion 1s, and the inspection device 70 of this embodiment also has this inspection function. Furthermore, in the present embodiment, the relative position is corrected based on the inspection result so that the relative position becomes the target relative position. Here, the correction of the relative position is not performed by changing the formation position of the seal portion 1s, but by changing the formation position of the absorber 3. The reason for this is as follows. The round seal device 60 that forms the seal portion 1s is disposed in the vicinity of the die cutter device 80, which is a synchronous reference device. Therefore, the round seal with respect to the punching position that is the processing position of the die cutter device 80 on the semi-finished product 1a. There is almost no shift in the formation position of the seal portion 1s as the processing position of the apparatus 60. Therefore, when the relative position between the seal portion 1s and the absorber 3 is shifted from the target relative position, the formation of the absorber 3 is exclusively performed. This is because it is considered that only the position is deviated from the reference processing position. Hereinafter, the inspection function for the presence / absence of abnormality in the relative position and the correction of the relative position between the seal portion and the absorber 3 will be described.

First, the inspection function will be explained. This inspection is also performed using the same planar image data used in the first binarization process. That is, as shown in the image diagram of the planar image in FIG. 10, from the planar image, the imaging part A1sed of the end seal part 1sed that is the downstream end part 1sed of the seal part 1s and the imaging part A3d of the downstream end part 3d of the absorber 3 The value of the distance Ded in the conveyance direction between the two is obtained, and whether or not there is an abnormality in the relative position is determined based on whether or not the value of the distance Ded falls within a specified target range. This will be described in detail below.

First, the image processing unit 76 calculates the value of the interval Ded. The calculation of the value of the interval Ded is performed by performing the third and fourth binarization processes on the planar image data. The inspection window W3 is also set in these third and fourth binarization processes. However, as shown in FIG. 10, the setting is an imaging portion A3d of the downstream end 3d in the transport direction of the absorber 3 and the downstream end 1sed of the seal portion 1s in the transport direction inside the inspection window W3. The imaging part A1sed of the end seal part 1sed is included.

In the third binarization process, a third binarization threshold value (corresponding to the third threshold value) stored in advance in the memory is used to acquire the white image of the imaging portion A1sed of the end seal portion 1sed. The binarization process is performed on the area in the inspection window W3. Specifically, the third binarization threshold is set to a value between the brightness of the pixel corresponding to the recess 1d of the seal portion 1s and the brightness of the pixel corresponding to the recess-unformed portion 1n where the recess 1d is not formed. ing. Then, among the pixels in the inspection window W3 in FIG. 11A, a pixel having a lightness equal to or higher than the third binarization threshold is selected as one of the binary values (for example, 0 and 1) in the binarized image in FIG. 11B. The white image specified by the value “1” is allocated to the white image, and the pixels having the lightness less than the third binarization threshold are allocated to the black image specified by the other value “0”. This is performed for all the pixels in the inspection window W3. Accordingly, among the pixels in the inspection window W3 in FIG. 11A, the imaging portion A1sed of the end seal portion 1sed is included in the white image in the binarized image as shown in FIG. 11B, and the other portions are black. It is processed so that it is almost included in the image.

On the other hand, in the fourth binarization process, in order to obtain a white image of the imaging portion A3d at the downstream end 3d of the absorber 3 (corresponding to “the end of the absorber in the transport direction”), it is stored in the memory in advance. Using the fourth threshold for binarization (corresponding to the fourth threshold), the region in the inspection window W3 is binarized. Specifically, the fourth threshold for binarization includes the brightness of the pixel corresponding to the portion 1g where only the top sheet 2a and the back sheet 4a overlap, the top sheet 2a, the absorber 3, and the back sheet 4a. Is set to a value between the lightness of the pixel corresponding to the portion 1r where the three members overlap. Then, among the pixels in the inspection window W3 in FIG. 11A, a pixel having a lightness equal to or lower than the fourth binarization threshold is selected as one of the binary values (for example, 0 and 1) in the binarized image in FIG. 11C. The white image specified by the value “1” is allocated to the white image, while the pixels having the brightness greater than the fourth binarization threshold are allocated to the black image specified by the other value “0”. This is performed for all the pixels in the inspection window W3. Thereby, among the pixels in the inspection window W3 of FIG. 11A, the imaging portion A3d (corresponding to “the imaging portion of the end portion of the absorber in the transport direction”) of the downstream end portion 3d of the absorber 3 corresponds to FIG. As shown in FIG. 4, the white image in the binarized image is included in the other portion (that is, the imaging portion A1g of the portion 1g where only the top sheet 2a and the back sheet overlap) is included in the black image. It is processed as follows.

Then, the image processing unit 76 converts the white image of the binarized image of FIG. 11B generated by the third binarization process and the binarized image of FIG. 11C generated by the fourth binarization process. Based on the white image, the value of the interval Ded is calculated. FIG. 11D is an explanatory diagram of this calculation.

Here, with respect to the value of the distance Ded, as shown in FIGS. 11B to 11D, for example, among the plurality of pixels constituting the white image (FIG. 11C) of the downstream end 3d of the absorber 3, the X direction Is located at the center in the X direction among the plurality of pixels constituting the white image (FIG. 11B) of the end seal portion 1sed from the Y coordinate Y3de of the pixel located at the most downstream in the transport direction. In addition, it can be obtained as a subtraction value (= Y3de−Y1sed) obtained by subtracting the Y coordinate Y1sed of the pixel located most upstream in the transport direction. Therefore, the image processing unit 76 performs such subtraction, thereby acquiring the value of the above-described interval Ded.

Next, the image processing unit 76 proceeds to a third abnormality determination process. In the third abnormality determination process, the value of the interval Ded is compared with a third abnormality determination threshold value to determine whether there is an abnormality in the relative position between the absorber 3 and the seal portion 1s. Here, the third abnormality determination threshold value is stored in the memory in advance as a numerical range. Note that the numerical range of the third abnormality determination threshold value can be acquired from, for example, the design drawing of the napkin 1. That is, in the design drawing, the target range of the interval between the end seal portion 1sed and the downstream end portion 3d of the absorbent body 3 on the center line in the width direction of the napkin 1 is defined, and thus the target of the interval is determined. By converting the range into a dimension on the Y coordinate system of the planar image, the numerical range of the third abnormality determination threshold value can be obtained.

When the value of the distance Ded is within the numerical range, it is determined that “the relative position between the absorber 3 and the seal portion 1s is within the target range”. On the other hand, when it is out of the same numerical range, it is determined that “the relative position between the absorber 3 and the seal portion 1 s does not fall within the target range”. In this case, the image processing unit 76 This determination result is transmitted to the control unit 18 of the rotary drum device 10 (FIG. 3).

Here, the determination result is accompanied by data of a value ΔDedr obtained by converting the deviation amount ΔDed obtained by subtracting the value of the interval Ded from the median of the numerical range of the third abnormality determination threshold value into an actual size. Then, the control unit 18 that has received this divides the deviation amount ΔDedr after conversion into the actual size by 360 ° after dividing by the total length of the unit semi-finished product 1b, thereby obtaining the phase deviation amount Δθ relating to the rotational operation of the rotary drum 12. Convert to Then, a phase correction instruction signal related to the rotation operation is transmitted to an amplifier of a servo motor (not shown) which is a drive source of the rotation operation of the rotary drum 12. The correction instruction signal is accompanied by the data of the phase shift amount Δθ described above, and this shift amount Δθ indicates how much the phase of the rotation angle value of the so-called synchronization signal should be advanced or delayed. ing. Therefore, the amplifier that has received this correction instruction signal changes the rotation angle value θ of the synchronization signal received by itself by gradually shifting the correction instruction signal by the amount of phase shift Δθ incidental to the correction instruction signal. Thereby, in the unit semi-finished product 1b including the absorber 3 generated by the rotary drum device 10 thereafter, the relative position between the absorber 3 and the seal portion 1s comes into the target range.

The image processing unit 76 corresponds to a “third binarization processing unit, a fourth binarization processing unit, and a third abnormality determination processing unit” according to the claims. That is, in the memory of the image processing unit 76, the third binarization processing program for generating the binarized image by performing the third binarization processing described above, and the fourth binarization processing described above. A fourth binarization processing program for generating a binarized image and a third abnormality determination processing program for performing the third abnormality determination processing described above are stored in advance, and the processor of the image processing unit 76 By appropriately reading and executing these programs, the image processing unit 76 functions as a third binarization processing unit, a fourth binarization processing unit, and a third abnormality determination processing unit.

By the way, the same value may be used for both the third binarization threshold and the second binarization threshold. In this case, based on the same inspection window, the binarized image generated by the third binarization process and the binarized image generated by the second binarization process are the same. Therefore, if the above-described second abnormality determination process is performed using the binarized image generated by the third binarization process, the joint abnormality of the end seal portion 1sed in the inspection window W3 is also inspected. Can do. In other words, in addition to the inspection of the relative position between the absorber 3 and the end seal portion 1sed, the image processing unit 76 performs the second binarization process when further checking the joining abnormality of the end seal portion 1sed. Without using the binarized image generated by the third binarization process, the joint abnormality of the end seal portion 1sed can be inspected. The processing unit 76 can reduce the calculation load. In other words, the second binarization processing program and the third binarization processing program can be configured as one common program. Accordingly, the concept of the invention described in the claims is that “the third binarization processing unit that is made to inspect the relative position between the end seal portion 1sed and the absorber 3 is a failure of the joint abnormality of the end seal portion 1sed. It also includes an aspect that “also serves as a second binarization processing unit necessary for performing the inspection”.

=== Other Embodiments ===
As mentioned above, although embodiment of this invention was described, said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. Further, the present invention can be changed or improved without departing from the gist thereof, and needless to say, the present invention includes equivalents thereof. For example, the following modifications are possible.

In the above-described embodiment, gray scale data in which the color information of each pixel has only brightness is shown as an example of planar image data, but the present invention is not limited to this. For example, the color information of each pixel may be color image data having brightness, hue, and saturation. In that case, color binarization processing can also be performed as the above-described binarization processing.
Incidentally, the color binarization process is a process of extracting pixels having specific color information from color image data of a planar image. Here, as described above, the color information has three elements of brightness, hue, and saturation as numerical values. Therefore, for each of lightness, hue, and saturation, the numerical value range of the color information of the pixel to be extracted can be preset in the memory of the image processing unit 76 as the first (or second) binarization threshold. For example, the image processing unit 76 can extract the pixel of the set color information from the planar image.
That is, the above-described three numerical ranges of the first (or second) binarization threshold are set to the region Ah in which the perforated portion h is imaged in the planar image (or the normal concave portion 1d that is not in an unjoined state). Image processing unit 76 refers to the color information of each pixel of the planar image recorded in the planar image data, and is preset based on the color unique to the area A1d) in which Pixels that satisfy all three numerical ranges of the first (or second) binarization threshold described above are allocated to, for example, white pixels, and pixels that do not satisfy the range are allocated to, for example, black pixels. Then, this allocation operation is performed for all the pixels of the planar image data, whereby the area Ah in which the perforated part h is imaged in the planar image (or the normal recess 1d that is not in an unjoined state) is imaged. Area A1d) is extracted as a white pixel area. According to this method, based on the color unique to the area Ah in which the perforated portion h is imaged (or the area A1d in which the normal concave portion 1d that is not in an unjoined state is imaged), the same area is obtained from the planar image. Since Ah (or region A1d) is extracted, the extraction accuracy can be improved. The contents other than those described above are the same as those already described with grayscale as an example, and the description thereof will be omitted.

In the above-described embodiment, the image processing unit 76 determines whether or not there is an abnormality based on the area of the white image in each binarized image, but the present invention is not limited to this. That is, as long as the value indicates the size of the white image, an appropriate instruction value other than the area may be used. For example, the presence or absence of abnormality may be determined based on the number of pixels of the white image. In that case, as the first and second abnormality determination threshold values, fixed values expressed by the number of pixels are set in the memory of each image processing unit 76 in advance.

In the above-described embodiment, in the second abnormality determination process related to the bonding abnormality inspection, the presence / absence of the bonding abnormality is determined based on the area of the white image including the normal recesses 1d, 1d. This is not a limitation. For example, the presence or absence of a bonding abnormality may be determined based on the area of a black image including the unbonded recesses 1dn, 1dn,. In this case, needless to say, the second abnormality determination threshold corresponding to the area of the black image is prepared in advance by the same experimental method as described above.

In the above-described embodiment, as shown in FIG. 10, the inspection of the relative position of the absorbent body 3 and the seal portion 1s in the conveyance direction is performed with the downstream end 1sed (downstream end seal portion 1sed) of the seal portion 1s and the absorption. Although it was performed based on the distance Ded in the transport direction between the downstream end 3d of the body 3 and the like, it is not limited to this. For example, as shown in FIG. 10, it is performed based on an interval Deu in the transport direction between the upstream end 1 seu (upstream end seal 1 seu) of the seal portion 1 s and the upstream end 3 u of the absorber 3. Anyway. In this case, the inspection window W3u includes an imaging part A3u at the upstream end 3u of the absorber 3 and an imaging part A1seu at the upstream end 1seu of the seal part 1s, as indicated by a three-dot chain line in FIG. Set to be included.

In the above-described embodiment, the CCD camera 72 is disposed to face the surface of the semi-finished product 1a on the surface sheet 2a side, and the illumination member 74 is disposed on the opposite side, but this arrangement relationship may be reversed. In other words, the camera 72 may be disposed to face the surface of the semi-finished product 1a on the back sheet 4a side, and the illumination member 74 may be disposed to face the surface of the semi-finished product 1a on the opposite side facing the surface sheet 2a. . Furthermore, the imaging of the camera 72 is not limited to the reception of the transmitted light from any semi-finished product 1a, that is, the reflected light from the semi-finished product 1a may be received and imaged. In this case, the illumination member 74 is disposed on the same side as the camera 72 with respect to the semi-finished product 1a, and the first to fourth binarization threshold values of the memory of the image processing unit 76, and the first to first threshold values. Needless to say, a value corresponding to the reflected light is set for each of the two abnormality determination thresholds.

1 Napkin (absorbent article, product), 1a Semi-finished product, 1a1 Three-layer structure part (first part), 1a2 Two-layer structure part (second part), 1b Unit semi-finished product (equivalent to absorbent article product) 1d recess, 1db bottom, 1dn unbonded recess (unbonded portion, unbonded portion), 1e outer edge, 1eb boundary, 1ec center, 1ee end, 1g, 1n not formed 1r part, 1s seal part, 1sed downstream end part (end seal part), 1sed1 end part (first seal part), 1sed2 center part (second seal part), 1seu upstream end part (end seal part), 1w wing Part, 2 surface sheet, 2a surface sheet continuous sheet, 2e end part, 2t embossed groove, 3 absorber, 3d downstream end part, 3u upstream end part, 4 back sheet, 4a back sheet continuous sheet, 4 Extruded part, 4w extended part, 6 side sheet, 6a side sheet continuous sheet, 6w part, 10 fiber stacking device, 12 rotating drum, 14 adsorption area, 16 duct, 18 control unit, 20 surface sheet supply roll , 30 Embossing device, 40 Side sheet supply roll, 50 Back sheet supply roll, 60 Round seal processing device, 60a Upper roll, 60b Lower roll, 64 Control unit, 70 Seal portion inspection device (Seal portion inspection device) 72 CCD camera (imaging processing unit), 74 illumination member, 76 image processing unit (first binarization processing unit, second binarization processing unit, third binarization processing unit, fourth binarization processing unit) , First abnormality determination processing unit, second abnormality determination processing unit, third abnormality determination processing unit), 80 die cutter device, 80a cutter roll, 80b anvil roll, 124 Conveyor (transport mechanism), h perforated part, area where A1d normal concave part is imaged, area where A1dn unjoined concave part is imaged, A1g part where only top sheet 2a and back sheet overlap Imaging part, A1s sealing part imaging part, A1sed end sealing part imaging part,
A1sed1 end region, A1sed2 center region, A1seu end seal portion imaging portion, A3d absorber downstream end portion imaging portion, A3u absorber upstream end portion imaging portion, Ah perforated portion region, PS imaging position, W1 inspection window (first inspection window), W2 inspection window (second inspection window), W3 inspection window (third inspection window), W3u inspection window (third inspection window), C60 rotation axis, C80 rotation Axis, S10 stacking process, S20 top sheet supply process, S30 emboss groove processing process, S40 side sheet supply process, S50 back sheet supply process, S60 round seal processing process, S70 seal part inspection process, S80 parting process

Claims (7)

1. An inspection device for a seal part that joins a plurality of sheets laminated in a thickness direction constituting an absorbent article at an outer edge part of the absorbent article,
   The seal portion is formed by pressing the plurality of stacked sheets in the thickness direction at the outer edge portion,
   An imaging processing unit that captures an image of an area where the seal portion is formed on one side of the plurality of sheets and generates planar image data of the area as planar image data;
   When generating the binarized image by binarizing the plane image data based on the first threshold value, the image specified by one of the binaries in the binarized image is displayed on the plane. A first binarization processing unit that performs binarization processing so as to include a region in which a perforated portion in a penetrating state is imaged in the thickness direction among imaging portions of the seal portion in the image;
   When generating the binarized image by binarizing the planar image data based on the second threshold value different from the first threshold value, the binarized image is specified by one of the binary values. The binarization processing is performed so that the image to be processed includes an area where the abnormally bonded portions of the plurality of sheets in the unbonded state are imaged among the imaged portions of the seal portion in the planar image. A binarization processing unit;
   Based on the binarized image generated by the first binarization processing unit, a first abnormality determination processing unit that determines the presence or absence of perforation abnormality;
   And a second abnormality determination processing unit that determines whether or not there is a bonding abnormality based on the binarized image generated by the second binarization processing unit. Inspection equipment.
2. An inspection device for a seal part according to claim 1,
   The plurality of sheets are conveyed in the conveyance direction in a continuous sheet state continuous in the conveyance direction,
   The seal part is formed side by side in the transport direction in a predetermined formation pattern for each unit corresponding to the product of the absorbent article,
   Before the plurality of sheets are divided into units corresponding to the product, the imaging processing unit images the region where the seal portion is formed, and inspects the seal portion according to the absorbent article apparatus.
3. An inspection device for a seal portion according to the absorbent article according to claim 1 or 2,
   The absorbent article includes a second portion in which a predetermined number of sheets of the plurality of sheets are stacked, and another sheet added to the predetermined number of sheets in the second portion and stacked. Having a first part,
   The seal part has a first seal part formed on the first part, and a second seal part formed on the second part,
   The first binarization processing unit sets a first inspection window that limits and binarizes a target region of the binarization processing in the planar image corresponding to the imaging portion of the first seal unit. ,
   The second binarization processing unit sets a second inspection window that limits the binarization processing target area in the planar image to be inward corresponding to the imaging portion of the second seal unit. An inspection apparatus for a seal portion according to an absorbent article.
4. An inspection device for a seal portion according to the absorbent article according to claim 1 or 2,
   The absorbent article has a longitudinal direction, a width direction, and a thickness direction,
   The absorbent article has a pair of wing portions extending in the width direction,
   The wing part is joined by the seal part in a state in which several sheets of the plurality of sheets are laminated.
   The second binarization processing unit defines a second inspection window that limits the binarization processing target area in the planar image inwardly in an imaging portion of the seal unit formed in the wing unit. A seal portion inspection apparatus according to an absorbent article, which is set correspondingly.
5. An inspection apparatus for a seal part according to any one of claims 1 to 4,
   The absorbent article has an absorbent body made of a liquid absorbent member between a pair of sheets among the plurality of sheets,
   The plurality of sheets are conveyed in the conveyance direction in a continuous sheet state continuous in the conveyance direction, and the absorber is arranged intermittently in the conveyance direction,
   The seal part has, as an end seal part, a portion located at the end in the transport direction rather than the absorber.
   When generating the binarized image by binarizing the plane image data based on the third threshold value, the image specified by one of the binaries in the binarized image A third binarization processing unit that performs binarization processing so as to include an imaging portion of the end seal portion in the image;
   When generating the binarized image by binarizing the plane image data based on the fourth threshold value, the image specified by one of the binaries in the binarized image A fourth binarization processing unit that performs binarization processing so as to include an imaging portion of an end of the absorber in the transport direction in the image;
   Based on the binarized image generated by the third binarization processing unit and the binarized image generated by the fourth binarization processing unit, the absorber and the seal unit in the transport direction, And a third abnormality determination processing unit that determines whether or not the relative position of the seal part falls within the target range.
6. An inspection apparatus for a seal part according to any one of claims 1 to 5,
   The determination of the presence or absence of perforation abnormality of the first abnormality determination processing unit indicates the size of the image specified by the one value among the binarized images generated by the first binarization processing unit. Based on the value,
   When the value indicating the size of the image is larger than a predetermined first abnormality determination threshold, the first abnormality determination processing unit determines that there is a holed abnormality,
   The determination of the presence or absence of a bonding abnormality in the second abnormality determination processing unit is performed on an image specified by a value that is not the one value among the binarized images generated by the second binarization processing unit. Based on the magnitude value,
   When the value indicating the size of the image is smaller than a prescribed second abnormality determination threshold, the second abnormality determination processing unit makes a determination that there is a bonding abnormality. Inspection equipment.
7. A method for inspecting a seal part that joins a plurality of sheets laminated in a thickness direction constituting an absorbent article at an outer edge part of the absorbent article,
   The seal portion is formed by pressing the plurality of stacked sheets in the thickness direction at the outer edge portion,
   Imaging a region where the seal portion is formed in one side of the plurality of sheets and generating plane image data of the region as plane image data;
   When generating the binarized image by binarizing the plane image data based on the first threshold value, the image specified by one of the binaries in the binarized image is displayed on the plane. Performing a first binarization process so as to include a region in which a perforated hole portion in the thickness direction is imaged among the imaging portions of the seal portion in the image;
   When generating the binarized image by binarizing the planar image data based on the second threshold value different from the first threshold value, the binarized image is specified by one of the binary values. The second binarization process is performed so that the image to be processed includes an area in which the abnormal bonding portion in which the plurality of sheets are not bonded is imaged among the imaging portions of the seal portion in the planar image. To do and
   Based on the binarized image generated by the first binarization process, determining whether there is a hole abnormality;
   A method for inspecting a seal portion according to an absorbent article, comprising: determining whether or not there is a bonding abnormality based on a binarized image generated by the second binarization process.

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