JP6725543B2 - Folding method - Google Patents

Description

The present invention relates to a folding method for folding an absorbent body while conveying the absorbent body having a longitudinal direction and a width direction orthogonal to the longitudinal direction along the longitudinal direction.

Patent Document 1 discloses a folding device that folds a web that continuously extends in one direction. The folding device folds a side region of the web, which is transported along the transport direction, along the transport direction, onto a central region in the orthogonal direction of the web (direction orthogonal to the transport direction).

JP, 2011-50478, A

The inventor of the present application has considered folding an absorbent body used in the absorbent article along a line along the longitudinal direction of the absorbent body in order to improve the functionality of the absorbent article such as a disposable diaper. Here, the absorbent body used in the absorbent article has a relatively low basis weight of the absorbent material or a low basis weight area having no absorbent material, and a relatively low basis weight area of the absorbent material compared to the low basis weight area. And a high basis weight region. When folding an absorber having a low basis weight region and a high basis weight region, the inventors of the present application have found that the following problems occur.

That is, when trying to fold the absorber, a strong load is applied to the absorber on the fold line in the process of folding the absorber. Therefore, if the fold line crosses the boundary between the low grammage region and the high grammage region or passes through the portion of the high grammage region close to the low grammage region, it will be The absorbent material in the grammage region may be pushed to the low grammage region, and the absorbent material in the high grammage region may collapse. When the absorbent material in the high grammage region collapses, the grammage distribution of the absorbent material varies on the fold line. If the absorbent body is to be folded with the line having the uneven basis weight distribution of the absorbent material as a base point, the folding line may be distorted in the width direction, and the absorbent body may not be stably folded.

Therefore, a folding method that can stably fold the absorbent body while maintaining the shape of the absorbent material is desired.

A folding method according to one aspect relates to a folding method that folds an absorbent body that includes an absorbent material and has a longitudinal direction and a width direction orthogonal to the longitudinal direction while conveying the absorbent body along the longitudinal direction. The absorber includes a first low basis weight region extending in the longitudinal direction and a pair of high basis weight regions adjacent to both sides of the first low basis weight region in the width direction. The folding method has a folding step of folding the absorber along a fold line along the first low basis weight region in a region between the pair of high basis weight regions.

According to the present invention, the absorber can be stably folded while maintaining the shapes of the high basis weight area and the low basis weight area.

FIG. 1 is a plan view of the absorbent body before being folded. 2 is a cross-sectional view of the absorber taken along the line 2A-2A in FIG. FIG. 3 is a schematic diagram showing a schematic configuration of a folding method for folding the absorber. FIG. 4 is a plan view showing an example of an adhesive application area in the application step. FIG. 5 is a perspective view showing the structure of the folding device. FIG. 6 is a plan view seen from the direction 6A in FIG. FIG. 7 is a plan view showing a folding step. 8 is a cross-sectional view taken along the line 8A-8A in FIG. 9 is a sectional view taken along the line 9A-9A in FIG. FIG. 10: is a figure explaining the position of the folding line formed in an absorber. FIG. 11 is a plan view showing an adhesive application area in the application step according to the second embodiment. FIG. 12 is a cross-sectional view showing a cross section of the folded absorber when the adhesive is applied to the application region shown in FIG. 11. FIG. 13 is a plan view showing a folding step according to the third embodiment. FIG. 14: is a top view of the absorbent article provided with the folded absorber. FIG. 15 is a cross-sectional view of the absorbent article taken along the line 15A-15A in FIG.

(1) Outline of Embodiments At least the following matters will be made clear by the present specification and the description of the accompanying drawings.

A folding method according to one aspect is a folding method of folding an absorbent body including an absorbent material and having a longitudinal direction and a width direction orthogonal to the longitudinal direction while conveying the absorbent body along the longitudinal direction. The folding method includes the absorbent body including a first low basis weight region extending in the longitudinal direction and a pair of high basis weight regions adjacent to both sides of the first low basis weight region in the width direction. Has a folding step of folding the absorber along a fold line along the first low basis weight region in a region between the pair of high basis weight regions.

According to this aspect, the folding line for folding the absorber extends along the first low basis weight region in the region between the pair of high basis weight regions. Specifically, the fold line extends along the first low basis weight region on the first low basis weight region or on the boundary between the first low basis weight region and the high basis weight region.

Low basis weight areas are generally softer than high basis weight areas. Therefore, since the folding line extends along the first low basis weight region in the region between the pair of high basis weight regions, the absorber can be stably folded.

In particular, the rigidity of the high basis weight region is generally higher than the rigidity of the first low basis weight region. That is, the first low grammage region is sandwiched between the high grammage regions having relatively high rigidity. Since the folding line is located in the region between the pair of high basis weight regions, a strong load is applied to the region between the pair of high basis weight regions during the folding step. Therefore, the absorbent material in the high basis weight region is unlikely to collapse toward the first low basis weight region. Further, since the first low basis weight region is sandwiched by the pair of relatively high rigidity high basis weight regions, even if a load is applied to the first low basis weight region, the shape of the first low basis weight region is large. Is also relatively stable. Therefore, during the folding step, the absorbent material is less likely to collapse and the basis weight distribution of the absorbent material is less likely to vary along the folding line. Since the absorbent body can be folded in a state where the basis weight distribution of the absorbent material on the fold line is uniform, the absorbent body can be stably folded.
Therefore, the absorber can be stably folded while maintaining the shape of the absorber.

According to a preferred aspect, a region between the pair of high basis weight regions is divided into three equal parts in the width direction, and a region located at the center in the width direction of the region between the pair of high basis weight regions is defined. When defined as the central region, the fold line is located outside the central region.

The stiffness of the high basis weight region is generally higher than the stiffness of the low basis weight region. Therefore, a rigidity difference occurs on the boundary between the high grammage region and the low grammage region. The line in which the difference in rigidity occurs extends in the longitudinal direction intermittently or continuously along the low basis weight region.

A region near the line where the difference in rigidity is generated is a region where the absorber is easily bent. In this aspect, since the folding line is located in the region where the absorber is easily bent, the absorber can be more stably folded.

According to a preferred aspect, the folding method has a first pressing step of pressing the absorber in the thickness direction before the folding step.

By pressing the absorber before the folding step, the thickness (maximum thickness) of the absorber is reduced. This makes it easier to cleanly break the absorbent body than the absorbent body before pressing.

According to a preferred aspect, at least before the first pressing step, the thickness of the high basis weight region is larger than the thickness of the low basis weight region.

As a result, in the first pressing step, the high grammage region is pressed more strongly than the low grammage region, and the rigidity of the high grammage region is further increased. As a result, the difference between the rigidity of the high basis weight region and the rigidity of the low basis weight region becomes larger. The larger difference in rigidity facilitates more stable folding of the absorbent body in the region near the boundary between the high grammage region and the low grammage region.

According to a preferred aspect, the folding method includes a second pressing step of pressing the absorber in the thickness direction after the folding step.

By pressing the absorber after the folding step, the creases of the absorber can be strongly formed, and the folded shape of the absorber can be stably maintained.

According to a preferred aspect, the first low basis weight region extends continuously in the longitudinal direction.

This makes the basis weight distribution of the absorbent material more uniform along the fold line. Therefore, the absorber can be folded more stably.

According to a preferred aspect, the folding method has an applying step of applying an adhesive to the folding area hidden inside the absorbent body by folding the absorbent body along the folding line before the folding step. ..

Since the folded region can be fixed with an adhesive, the folded shape of the absorber can be maintained more stably.

According to a preferred aspect, in the applying step, the adhesive is applied to the first low basis weight region.

According to this aspect, since the layers coated with the adhesive do not overlap doubly after the absorber is folded, it is possible to suppress an increase in the total thickness of the adhesive layers. As a result, it is possible to prevent the portion coated with the adhesive from becoming too hard, and thus to provide a soft absorber.

According to a preferred position mode, in the applying step, the adhesive is applied to the absorbent body in a state where a coating machine for applying the adhesive is separated from the absorbent body.

If the adhesive is applied to the absorbent body while pressing the absorbent body, the adhesive easily permeates into the absorbent body. In some cases, the adhesive may ooze out from the back side of the absorbent body, and the adhesive may adhere to the members forming the folding device of the absorbent body.

According to this aspect, since the absorbent body is not pressed when the adhesive is applied to the absorbent body, it is possible to prevent the adhesive from seeping out from the back side of the absorbent body and adhering to the member constituting the folding device. ..

According to a preferred aspect, the absorber has a cover sheet that wraps the absorbent material, and the cover sheet is bonded to the absorbent material with an adhesive.

According to this aspect, the absorbent material is wrapped and held by the cover sheet. Therefore, it is possible to prevent the shapes of the high basis weight region and the low basis weight region from collapsing. This allows the absorber to be folded more stably while maintaining the shape of the absorbent material.

According to a preferred aspect, the absorber includes a second low basis weight region extending in the longitudinal direction, and a pair of high basis weight regions adjacent to both sides of the second low basis weight region, In the folding step, after folding the absorber at the fold line along the first low basis weight region in the region between the pair of high basis weight regions adjacent to both sides of the first low basis weight region, The absorbent body is folded along a fold line along the second low basis weight region in a region between a pair of high basis weight regions adjacent to both sides of the second low basis weight region.

According to this aspect, it is not necessary to simultaneously deform both sides in the width direction of the absorber during the folding step. Thereby, the absorber can be neatly folded along the folding line.

According to a preferred aspect, the absorber includes a second low basis weight region extending in the longitudinal direction, and a pair of high basis weight regions adjacent to both sides of the second low basis weight region, In the folding step, at the same time when the absorber is folded at the fold line along the first low basis weight region in a region between a pair of high basis weight regions adjacent to both sides of the first low basis weight region. Or, before finishing folding, the absorbent body is folded along a fold line along the second low basis weight region in a region between a pair of high basis weight regions adjacent to both sides of the second low basis weight region.

According to this aspect, since both sides in the width direction of the absorber are simultaneously bent during the folding step, the absorber is prevented from shifting in the width direction. This prevents the position of the folding line from shifting in the width direction. Further, the time required for the folding step can be shortened as compared with the case where two foldings are performed at different timings.

(2) First Embodiment Hereinafter, a folding method according to the first embodiment will be described with reference to the drawings. In the following description of the drawings, the same or similar reference numerals are given to the same or similar parts. However, it should be noted that the drawings are schematic and ratios of respective dimensions and the like are different from actual ones. Therefore, specific dimensions should be determined in consideration of the following description. Further, the drawings may include portions having different dimensional relationships and ratios.

The folding method according to the present embodiment relates to a method of folding an absorber. The absorbent body folded by the main folding method can be used as a constituent element of an absorbent article such as a disposable diaper or a sanitary napkin.

FIG. 1 is a plan view of the absorbent body before being folded. 2 is a cross-sectional view of the absorber taken along the line 2A-2A in FIG. The absorber 40 has a longitudinal direction L and a width direction W orthogonal to the longitudinal direction L. In the present embodiment, the absorbent body 40 extends continuously in the longitudinal direction L and is not cut into the length applied to each article in the longitudinal direction L.

The absorber 40 includes an absorbent material 41 that absorbs a liquid such as urine, and a cover sheet 46 that wraps the absorbent material 41. The absorbent material 41 includes at least one of hydrophilic fiber, pulp, and super absorbent polymer.

The cover sheet 46 may include a first sheet 46a and a second sheet 46b. The first sheet 46a covers one surface of the absorbent material 41. The second sheet 46b is provided on the opposite side of the absorbent material 41 from the first sheet 46a. Both ends of the second sheet 46b in the width direction W are folded back to the first sheet 46a side and cover the ends of the first sheet 46a in the width direction. The first sheet 46a and the second sheet 46b can be made of a non-woven fabric, a tissue, or a combination thereof.

The cover sheet 46 is preferably adhered to the absorbent material with an adhesive 50. Specifically, it is preferable that both the first sheet 46a and the second sheet 46b are bonded to the absorbent material with the adhesive 50.

The absorber 40 includes a first low basis weight region 42a, a second low basis weight region 42b, and high basis weight regions 44a, 44b, 44c. The high basis weight regions 44a, 44b, and 44c are regions including the absorbent material 41 having a larger basis weight than the first low basis weight region 42a and the second low basis weight region 42b. The first low basis weight area 42a and the second low basis weight area 42b are areas including the absorbent material 41 having a smaller basis weight than the high basis weight areas 44a, 44b, 44c, or the basis weight of the absorbent material is substantially zero. Area. Here, the grammage of the absorbent material being substantially zero means that the grammage of the absorbent material in the design is zero, and means a concept including the inclusion of a small amount of the absorbent material in the manufacturing process. Note that FIG. 2 shows an example of an absorber in which the first low basis weight region 42a and the second low basis weight region 42b do not substantially include the absorbent material 41.

The thickness of the first low basis weight region 42a and the second low basis weight region 42b may be thicker than the thickness of the high basis weight regions 44a, 44b, 44c. Further, the thickness of the first low basis weight region 42a and the second low basis weight region 42b may be substantially the same as the thickness of the high basis weight regions 44a, 44b, 44c.

The first low basis weight region 42a and the second low basis weight region 42b extend along the longitudinal direction L. Preferably, the first low basis weight region 42a and/or the second low basis weight region 42b continuously extends in the longitudinal direction L.

The high grammage regions 44a and 44b are provided adjacent to both sides of the first low grammage region 42a in the width direction W. The high grammage regions 44b and 44c are provided adjacent to both sides of the second low grammage region 42b in the width direction W.

In the absorber 40 according to the first embodiment, the high basis weight regions 44a, 44b, 44c continuously extend in the longitudinal direction L. Alternatively, the high basis weight regions 44a, 44b, 44c may be provided intermittently in the longitudinal direction L. That is, the high basis weight regions 44a, 44b, 44c may be configured by a plurality of regions separated in the longitudinal direction L.

FIG. 3 is a schematic diagram showing a schematic configuration of a folding method for folding the absorber. The folding method includes a first pressing step S1, a coating step S2, a folding step S3, and a second pressing step S4. In the first pressing step S1, the absorber 40 described above is pressed in the thickness direction. In the applying step S2, the adhesive is applied to a part of the area on the absorber 40. In the folding step S3, the absorber 40 is folded along the longitudinal direction L. In the second pressing step S4, the folded absorber 40 is pressed in the thickness direction. These series of steps S1 to S4 are performed while the absorber 40 is being transported in the transport direction MD. The transport direction MD is the same as the longitudinal direction L of the absorber 40. Hereinafter, each step will be described in detail.

First, the first pressing step S1 is performed before the folding step S3. In the first pressing step S1, the absorber 40 described above is pressed in the thickness direction. As an example, the absorber 40 is pressed in the thickness direction by a pair of rollers 200 and 202 facing each other. By pressing the absorber 40 before the folding step S3, the thickness (maximum thickness) of the absorber 40 is reduced. Thereby, in the folding step S3, the absorber 40 can be folded more easily and neatly.

The first pressing step S1 is an arbitrary step and may be performed as needed.

Next, a coating step S2 of coating an adhesive on the absorber is performed. A coating machine 300 for applying an adhesive is provided on a transport path for transporting the absorber. The coating machine 300 is located away from the absorber 40 that is transported on the transport path. The coating machine 300 discharges the adhesive toward the absorber 40 being conveyed. It is preferable that the coating machine 300 apply the adhesive to the absorber 40 in a state of being separated from the absorber.

If the adhesive is applied to the absorbent body 40 while the coating machine 300 is pressed against the absorbent body 40, the adhesive may seep into the absorbent body, and in some cases, the adhesive may seep out from the back side of the absorbent body 40. is there. As a result, the adhesive may adhere to a member such as a roller that conveys the absorber 40. According to this embodiment, since the absorber 40 is not pressed when the adhesive is applied to the absorber 40, the adhesive is unlikely to seep out from the back side of the absorber 40. Therefore, it is possible to prevent the adhesive from adhering to the members constituting the device that performs the folding method.

FIG. 4 shows an example of the application area of the adhesive 54 discharged by the coating machine 300. The adhesive 54 is applied to at least a part of the region within the folding range of the absorber 40. Here, the folding range of the absorber 40 is defined by the range hidden inside the absorber 40 by folding the absorber 40 in the folding step S3. That is, the folding range of the absorber 40 is a range that is not exposed on the surface of the absorber 40 after the folding step S3. Since the adhesive agent 54 is applied to at least a part of the area within the folded area of the absorbent body 40, the folded area of the absorbent body 40 can be firmly fixed with the adhesive agent 54 after the folding step S3. Therefore, the shape of the folded absorber 40 can be stably maintained.

The coating step S2 is an arbitrary step and may be performed as needed.

Next, a folding step S3 of folding the absorber is performed. FIG. 5 is a perspective view showing an example of the configuration of the folding device. FIG. 6 is a plan view seen from the direction 6A in FIG. The folding device includes a transport mechanism 150 that transports the absorber 40, a first guide plate 140, and a second guide plate 142.

The transport mechanism 150 may include a transport belt 153 and a suction mechanism 157. The conveyor belt 153 is an endless belt wound around a pair of rollers 151 and 152. The conveyor belt 153 has a suction hole 155. The suction mechanism 157 suctions the absorber 40 via the suction holes 155 of the conveyor belt 153. As a result, the absorber 40 is suction-held on the conveyor belt 153.

When the fold line of the absorbent body 40 is formed in the first low basis weight region 42a and the second low basis weight region 42b, a region between the first low basis weight region 42a and the second low basis weight region 42b, that is, It is preferable that the high basis weight region 44b is suction-held on the conveyor belt 153. As a result, the region of the absorbent body 40 that is not folded back can be firmly held on the conveyor belt 153.

The first guide plate 140 and the second guide plate 142 are arranged at positions apart from the transport belt 153 in the direction orthogonal to the transport belt 153. That is, there is a gap between the conveyor belt 153 and the first guide plate 140. Similarly, there is a gap between the conveyor belt 153 and the second guide plate 142.

The first guide plate 140 folds one side portion (first side portion) 40a of the absorber 40 in the width direction W on the conveyor belt 153 (see FIG. 7 ). The second guide plate 142 folds the other side portion (second side portion) 40b of the absorber 40 in the width direction W on the conveyor belt (see FIG. 7 ).

The first guide plate 140 extends along the transport direction MD. One end 140e of the first guide plate in the cross direction CD orthogonal to the transport direction MD is inclined from the outer side to the inner side of the absorber in the width direction as it goes downstream.

The second guide plate 142 extends along the transport direction MD. The one end portion 142e of the second guide plate in the cross direction CD orthogonal to the transport direction MD is inclined from the outer side to the inner side of the absorber in the width direction as it goes downstream.

FIG. 7 is a plan view showing the folding step S3 according to this embodiment. 8 is a cross-sectional view taken along the line 8A-8A in FIG. 9 is a sectional view taken along the line 9A-9A in FIG. 8 and 9, the cross section of the absorber 40 is schematically drawn for simplification.

When the absorber 40 passes through the area where the first guide plate 140 and the second guide plate 142 are provided, the absorber 40 is suction-held by the conveyor belt 153. When the absorber 40 enters the first guide plate 140 and the second guide plate 142, the first side portion 40a and the second side portion 40b of the absorber, that is, the high basis weight regions 44a and 44c of the absorber 40 respectively move to the first side. It is placed on the first guide plate 140 and the second guide plate 142 (see FIG. 8). At this time, the high basis weight region 44 b located at the center of the absorber 40 is suction-held by the transport belt 153 by the suction holes 155. The absorber 40 is conveyed downstream, and the end portion 140e of the first guide plate and the end portion 142e of the second guide plate approach the center of the absorber 40 in the width direction W. As a result, the end portion 140e of the first guide plate pushes the region between the pair of high basis weight regions 44a and 44b inward in the width direction (see FIG. 9). Therefore, as shown in FIG. 9, the absorber 40 is folded into a Z-shape in a cross-sectional view in the region between the pair of high basis weight regions 44a and 44b. Similarly, the end portion 142e of the second guide plate pushes the area between the pair of high basis weight areas 44b and 44c inward in the width direction (see FIG. 9). Therefore, as shown in FIG. 9, the absorbent body 40 is folded into a Z shape in a cross-sectional view in the region between the pair of high basis weight regions 44b and 44c. The absorber 40 may be folded such that the inner end portions of the high basis weight regions 44a and 44c in the width direction W are placed on the high basis weight region 44b.

The position of the first guide plate 140 is the first low basis weight region 42a in a region between the pair of high basis weight regions 44a and 44b where the first folding lines FL1a and FL1b formed on the first side portion 40a of the absorber are located. Is set to extend along. Here, the area between the pair of high basis weight areas 44a and 44b means the inside of the first low basis weight area 42a or the boundary between the first low basis weight area 42a and the high basis weight areas 44a and 44b. ..

Similarly, the position of the second guide plate 142 is set such that the second folding lines FL2a and FL2b formed on the second side portion 40b of the absorbent body are in the region between the pair of high basis weight regions 44b and 44c. It is set so as to extend along the quantity region 42b. Here, the area between the pair of high basis weight areas 44b and 44c means the inside of the second low basis weight area 42b or the boundary between the second low basis weight area 42b and the high basis weight areas 44b and 44c. ..

In the present embodiment, the absorber 40 is folded along the fold lines along the low basis weight regions 42a, 42b in the region between the pair of high basis weight regions 44a, 44b, 44c. The low basis weight regions 42a, 42b are generally softer than the high basis weight regions 44a, 44b, 44c. Therefore, the fold lines FL1a, FL1b, FL2a, FL2b extend along the low basis weight regions 42a, 42b in the region between the pair of high basis weight regions 44a, 44b, 44c, thereby stabilizing the absorber 40. Can be folded into

In particular, the stiffness of the high basis weight regions 44a, 44b, 44c is generally higher than the stiffness of the low basis weight regions 42a, 42b. That is, the low grammage regions 42a and 42b are sandwiched by the high grammage regions 44a, 44b, and 44c having relatively high rigidity. Since the fold lines FL1a, FL1b, FL2a, FL2b are located in the region between the pair of high basis weight regions 44a, 44b, 44c, during the folding step S3, between the pair of high basis weight regions 44a, 44b, 44c. The area is heavily loaded. Therefore, the absorbent material in the high basis weight regions 44a, 44b, 44c is unlikely to collapse toward the low basis weight regions 42a, 42b. Further, since the low basis weight regions 42a, 42b are sandwiched by the pair of relatively high rigidity high basis weight regions 44a, 44b, 44c, even if a load is applied to the low basis weight regions 42a, 42b, the The shapes of the basis weight regions 42a and 42b are also relatively stable. Therefore, during the folding step S3, the absorbent material is less likely to collapse, and variations in the basis weight distribution of the absorbent material are less likely to occur on the folding lines FL1a, FL1b, FL2a, FL2b. Since the absorbent body can be folded in a state where the basis weight distribution of the absorbent material on the folding lines FL1a, FL1b, FL2a, FL2b is uniform, the absorbent body 40 can be stably folded.

Further, when the basis weight of the absorbent material in the low basis weight regions 42a and 42b is substantially zero, the shape of the absorbent material is not substantially collapsed, and the absorbent body 40 can be folded more stably. .. Therefore, the absorber can be stably folded while maintaining the shape of the absorber.

Moreover, when the absorber 40 continuously extends long in the longitudinal direction L, the shape of the absorber 40 on the upstream side is easily deformed following the shape of the absorber 40 folded on the downstream side. Therefore, it becomes easier to fold the absorber 40 than when the absorber 40 divided into individual product lengths is folded.

The position where the absorber 40 is folded, that is, the more preferable position of the folding lines FL1a, FL1b, FL2a, FL2b will be described with reference to FIG. FIG. 10: is a figure explaining the position of the folding line formed in an absorber. FIG. 10 is an enlarged view showing a state in which the absorber 40 folded in the folding step S3 is expanded. In FIG. 10, two dotted lines that divide the region between the pair of high basis weight regions, that is, the low basis weight regions 42a and 42b into three equal parts in the width direction W are shown. Here, the region located at the center in the width direction of the region between the pair of high basis weight regions is defined as the central region Rc. A region located on a side portion in the width direction of the region between the pair of high basis weight regions is defined as a side region Re.

Fold lines FL1a, FL1b, FL2a, FL2b are regions between the pair of high basis weight regions 44a, 44b, 44c, and are preferably located outside the central region Rc.

The stiffness of the high basis weight regions 44a, 44b, 44c is generally higher than the stiffness of the low basis weight regions 42a, 42b. Therefore, a difference in rigidity occurs on the boundary between the high grammage regions 44a, 44b and 44c and the low grammage regions 42a and 42b. When the high grammage regions 44a, 44b, and 44c continuously extend in the longitudinal direction, the line having the difference in rigidity extends continuously in the longitudinal direction L along the low grammage regions 42a and 42b. Instead, when the high grammage regions 44a, 44b, 44c extend intermittently in the longitudinal direction, the line in which the difference in rigidity occurs is discontinuous in the longitudinal direction along the low grammage regions 42a, 42b. Extends to L.

The side regions Re are regions where the absorber 40 is easily bent due to the difference in rigidity. As shown in FIG. 10, when the folding lines FL1a, FL1b, FL2a, FL2b are located outside the central region Rc, the absorber 40 is easily bent, and the absorber 40 can be folded more stably.

Further, the folding lines FL1a, FL1b, FL2a, FL2b may be located at the boundaries between the low basis weight regions 42a, 42b and the high basis weight regions 44a, 44b, 44c, respectively. In this case, the absorber 40 can be folded more neatly along the folding lines FL1a, FL1b, FL2a, FL2b due to the difference in rigidity between the low basis weight regions 42a, 42b and the high basis weight regions 44a, 44b, 44c.

Further, in the present embodiment, the region between the two folding lines FL1a and FL1b is the low basis weight region 42a. Similarly, the area between the two folding lines FL2a and FL2b is the low basis weight area 42b. When folded in a Z-shape in cross section, a strong load is likely to be applied to the region between the two folding lines, so that the region between the two folding lines is also preferably a relatively soft low basis weight region.

At least before the first pressing step S1, the thickness of the high basis weight regions 44a, 44b, 44c is preferably larger than the thickness of the low basis weight regions 42a, 42b. In this case, in the first pressing step S1, the high basis weight regions 44a, 44b, 44c are pressed more strongly than the low basis weight regions 42a, 42b, and the rigidity of the high basis weight regions 44a, 44b, 44c becomes higher. As a result, the difference between the rigidity of the high basis weight regions 44a, 44b, 44c and the rigidity of the low basis weight regions 42a, 42b becomes larger. The larger difference in rigidity facilitates more stable folding of the absorbent body 40 in the region near the boundary between the high basis weight regions 44a, 44b, 44c and the low basis weight regions 42a, 42b.

When the first low basis weight region 42a and/or the second low basis weight region 42b extend continuously in the longitudinal direction L, the distribution of the basis weight of the absorbent material along the folding lines FL1a, FL1b, FL2a, FL2b. Becomes more uniform. Therefore, the absorber 40 can be folded more stably.

When the cover sheet 46 is adhered to the absorbent material 41 with the adhesive 50, the absorbent material 41 is wrapped with the cover sheet 46 and firmly held. Therefore, it is possible to prevent the shapes of the high basis weight regions 44a, 44b, and 44c, the first low basis weight region 42a, and the second low basis weight region 42b from collapsing. This allows the absorber to be folded more stably while maintaining the shape of the absorbent material.

In the first embodiment, in the folding step S3, the folding line FL1a along the first low basis weight region 42a in the region between the pair of high basis weight regions 44a and 44b adjacent to both sides of the first low basis weight region 42a. , FL1b, at the same time when the absorbent body is started to be folded or before the folding is finished, in the region between the pair of high basis weight regions 44b and 44c adjacent to both sides of the second low basis weight region 42b. The absorber 40 is folded along the folding lines FL2a and FL2b along the line 42b. That is, the period for folding the first side portion 40a of the absorber 40 at least partially overlaps with the period for folding the second side portion 40b of the absorber 40.

Thus, during the folding step S3, both sides of the absorbent body 40 in the width direction W are bent at the same time, so that an external force is applied to the absorbent body 40 from both sides in the width direction toward the center. Therefore, the absorber 40 is prevented from shifting in the width direction W. As a result, the positions of the folding lines FL1a, FL1b, FL2a, FL2b are suppressed from shifting in the width direction. Furthermore, the time required for the folding step S3 can be shortened as compared with the case where the first side portion 40a of the absorber 40 and the second side portion 40a of the absorber 40 are folded at different timings.

Further, as described above, it is preferable that the adhesive 54 is applied to the folding range of the absorber 40 before the folding step S3 (application step S2). In the aspect shown in FIG. 4, the adhesive 54 is provided across the first low basis weight region 42a and the high basis weight region 44b. In this case, as shown in FIG. 9, the adhesive 54 overlaps two layers in a state where the first side portion 40a and the second side portion 40b of the absorber 40 are folded. In this case, the shape of the folded absorber 40 is more easily maintained.

It is preferable to perform the second pressing step S4 of pressing the absorber 40 in the thickness direction after the folding step S3. The absorber 40 is pressed by being sandwiched between a pair of pressing rollers 400 and 402, for example. By pressing the absorber 40 after the folding step S3, a strong crease can be formed on the absorber 40, and the shape of the folded absorber can be stably maintained.

The second pressing step S4 is an arbitrary step and may be performed as needed.

After the second pressing step S4, the absorber 40 is cut into a predetermined length in the longitudinal direction L. Thereby, a plurality of absorbers having a predetermined length can be obtained. The absorbent body thus obtained can be applied to absorbent articles such as disposable diapers and sanitary napkins. In this case, the method for folding the absorbent body described above can be used as one step of the method for manufacturing the absorbent article. That is, the device shown in FIG. 3 can be applied as a part of a production line for absorbent articles. In addition, the manufacturing method of the absorbent article can be carried out by a known method except for the method of folding the absorbent body described above.

(3) Second Embodiment Next, a folding method according to the second embodiment will be described. In the second embodiment, description of the same configurations and steps as those in the first embodiment may be omitted.

The folding method according to the second embodiment may include a first pressing step S1, a coating step S2, a folding step S3, and a second pressing step S4, as in the first embodiment. However, the application area of the adhesive 54 in the application step S2 is different from that of the first embodiment. Hereinafter, the application area of the adhesive 54 according to the second embodiment will be described with reference to FIGS. 11 and 12.

FIG. 11 is a plan view showing an application area of the adhesive 54 in the application step according to the second embodiment. FIG. 12 is a cross-sectional view showing a cross section of the absorber after the folding step S3 when the adhesive 54 is applied to the application region shown in FIG.

The adhesive 54 is provided only in the first low basis weight region 42a and the second low basis weight region 42b within the folding range of the absorber 40. In this case, as shown in FIG. 12, the adhesive 54 does not overlap doubly when the first side portion 40a and the second side portion 40b of the absorber 40 are folded. Since the layers to which the adhesive 54 is applied do not overlap doubly, it is possible to prevent the total thickness of the adhesive 54 from increasing. As a result, it is possible to prevent the portion to which the adhesive 54 is applied from becoming too hard, and thus to provide the soft absorber 40.

(4) Third Embodiment Next, a folding method according to the third embodiment will be described. In the third embodiment, description of the same configurations and steps as in the first embodiment may be omitted.

The folding method according to the third embodiment may include a first pressing step S1, a coating step S2, a folding step S3, and a second pressing step S4, as in the first embodiment. However, in the folding step S3, the timing of folding the first side portion 40a and the second side portion 40b of the absorber 40 is different from that in the first embodiment. The folding step S3 according to the third embodiment will be described below with reference to FIG.

FIG. 13 is a plan view showing a folding step according to the third embodiment. In the third embodiment, the folding device includes a first guide plate 140 and a second guide plate 142. The first guide plate 140 folds one side portion (first side portion) 40 a of the absorber 40 in the width direction W on the conveyor belt 153. The second guide plate 142 folds the other side portion (second side portion) 40b of the absorber 40 in the width direction W on the conveyor belt.

The configurations of the first guide plate 140 and the second guide plate 142 are similar to those of the first embodiment. However, in the third embodiment, the first guide plate 140 and the second guide plate 142 are separated from each other in the transport direction L.

In the folding step S3, in the region between the pair of high basis weight regions 44a and 44b which are adjacent to both sides of the first low basis weight region 42a, the first line of the absorbent body is drawn along the folding line along the first low basis weight region 42a. After folding the side portion 40a, a fold line along the second low basis weight region 42b in a region between the pair of high basis weight regions 44b and 44c adjacent to both sides of the second low basis weight region 42b is used. Fold the first side portion 40b.

According to this aspect, it is not necessary to simultaneously deform (bend) both the first side portion 40b and the second side portion 40b of the absorber during the folding step. Therefore, the side portions of the absorber can be accurately folded one by one, so that the absorber 40 can be neatly folded along the folding line.

(5) Example of article provided with absorbent body An example of an article provided with the absorbent body 40 folded as described above will be described below. The absorbent body can be applied to absorbent articles such as disposable diapers and sanitary napkins. Hereinafter, the configuration of the absorbent article including the absorber 40 will be described with reference to FIGS. 14 and 15. The same components as those of the absorber described in the first embodiment are designated by the same reference numerals.

FIG. 14: is a top view of the absorbent article provided with the folded absorber. FIG. 15 is a cross-sectional view of the absorbent article taken along the line 15A-15A in FIG.

The absorbent article 10 includes an absorber 40, a topsheet 20 arranged on the skin side of the absorber 40, and a backsheet 30 arranged on the non-skin side of the absorber 40. The absorber 40 is folded as described in the first to third embodiments.

The absorber 40 has high basis weight areas 44a, 44b, 44c, a first low basis weight area 42a, and a second low basis weight area 42b. The ends of the outer high grammage regions 44a and 44c in the width direction W are placed on the central high grammage region 44b in the width direction W. The first low basis weight region 42a is located between the high basis weight region 44a and the high basis weight region 44b, and is connected to the high basis weight regions 44a and 44b. The second low basis weight region 42b is located between the high basis weight region 44b and the high basis weight region 44c, and is connected to the high basis weight regions 44b and 44c.

According to such an absorbent article, the thickness of the central portion of the absorbent body in the width direction W becomes relatively thin. On the other hand, the area adjacent to the central portion of the absorbent body in the width direction W is a tatami area where the high basis weight area 44b, the low basis weight area 42a or 42b, and the high basis weight area 44a or 44b overlap. Therefore, it becomes relatively thick. Therefore, since the central portion of the absorber 40 in the width direction W is recessed toward the non-skin surface side, a space extending in the longitudinal direction is formed between the wearer and the absorber 40. The body fluid can be diffused in the longitudinal direction by the space, and it becomes easy to effectively utilize the liquid absorbing performance over the entire region of the absorber 40 in the longitudinal direction.

Further, the ends of the absorber 40 in the width direction W are high basis weight regions 44a and 44c. Therefore, the end portion of the absorber 40 in the width direction W is thinner than the thickness of the tatami mat region. Therefore, the uncomfortable feeling around the legs of the wearer can be reduced.

(6) Other Embodiments Although the present invention has been described in detail above by using the above-described embodiments, those skilled in the art will understand that the present invention is not limited to the embodiments described in this specification. That is clear. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the claims. Therefore, the description of the present specification is for the purpose of exemplifying explanation, and does not have any restrictive meaning to the present invention.

For example, in the above-described embodiment, during the folding method, the absorbent body 40 continuously extends in the longitudinal direction L and is not cut into the length applied to the individual articles in the longitudinal direction L. Alternatively, the absorbent body may be folded in a state of being divided into a predetermined length applied to the intended product.

Moreover, in the said embodiment, both side parts 40a, 40b of the absorber 40 are folded in Z shape by a cross sectional view. Alternatively, both side parts 40a and 40b of the absorber 40 may be folded back in a U-shape in a sectional view. In this case, during the folding step S3, both side portions 40a, 40b of the absorber 40 may be folded back without placing the both side portions 40a, 40b on the guide plates 140, 142.

Further, in the above-described embodiment, both side portions 40a, 40b of the both side portions 40a, 40b of the absorber 40 are folded. Alternatively, only one side 40a or 40b of the absorber 40 may be folded. In this case, only one of the first guide plate 140 and the second guide plate 142 may be used in the folding step S3.

40 Absorber 41 Absorbent 42a First low basis weight region 42b Second low basis weight region 44a, 44b, 44c High basis weight region 46 Core wrap 54 Adhesive 140 First guide plate 142 Second guide plate FL1a, FL1b, FL2a, FL2b Folding line S1 First pressing step S2 Coating step S3 Folding step S4 First pressing step

Claims (13)

A folding method, comprising an absorbent material, having a longitudinal direction and a width direction orthogonal to the longitudinal direction, folding the absorbent body while conveying the absorbent body along the longitudinal direction,
The absorber is
A first low basis weight region extending in the longitudinal direction,
A pair of high basis weight regions adjacent to both sides of the first low basis weight region in the width direction,
The folding method is the two fold lines along said first low basis weight regions in the region between the pair of high basis weight regions, have a step folding folding the absorbent body in the Z-shape in cross section ,
The area between the two folding lines is the first low basis weight area . When the area between the pair of high basis weight areas is divided into three equal parts in the width direction, and the area located in the center in the width direction of the area between the pair of high basis weight areas is defined as the central area, The folding method according to claim 1, wherein the two folding lines are located outside the central region. The folding method according to claim 1 or 2, further comprising a first pressing step of pressing the absorber in the thickness direction before the folding step. The folding method according to claim 3, wherein the thickness of the high basis weight region is larger than the thickness of the first low basis weight region at least before the first pressing step. The folding method according to claim 1, further comprising a second pressing step that presses the absorber in the thickness direction after the folding step. The folding method according to claim 1, wherein the first low basis weight region continuously extends in the longitudinal direction. 7. The method according to claim 1, further comprising an applying step of applying an adhesive to a folding range hidden inside the absorbent body by folding the absorbent body along the two folding lines before the folding step. The folding method according to item 1. The folding method according to claim 7, wherein in the applying step, the adhesive is applied to the first low basis weight region. 9. The folding method according to claim 7, wherein, in the applying step, the adhesive is applied to the absorbent body in a state where a coating machine for applying the adhesive is separated from the absorbent body. The absorbent body has a cover sheet that wraps the absorbent material,
The folding method according to claim 1, wherein the cover sheet is adhered to the absorbent material with an adhesive. The absorber is
A second low basis weight region extending in the longitudinal direction,
A pair of high basis weight regions adjacent to both sides of the second low basis weight region,
In the folding step, the two folding lines along the first low basis weight region in the region between the pair of high basis weight regions adjacent to both sides of the first low basis weight region, After the folding , the two absorption lines are absorbed by the two second fold lines along the second low basis weight area in the area between the pair of high basis weight areas adjacent to both sides of the second low basis weight area. The folding method according to claim 1, wherein the body is folded. The absorber is
A second low basis weight region extending in the longitudinal direction,
A pair of high basis weight regions adjacent to both sides of the second low basis weight region,
In the folding step, the two folding lines along the first low basis weight region in the region between the pair of high basis weight regions adjacent to both sides of the first low basis weight region, Simultaneously with the start of folding, or before finishing the folding, two second low basis weight areas are provided along the second low basis weight area in a region between the pair of high basis weight areas adjacent to both sides of the second low basis weight area. The folding method according to any one of claims 1 to 10, wherein the absorbent body is folded along two folding lines. In the folding step, one side portion in the width direction of the absorber is placed on the guide plate. The end portion of the guide plate approaches the center of the absorber in the width direction, The folding according to any one of claims 1 to 12, wherein the absorbent body is folded in a Z shape in the cross-sectional view. Method.

Images