JP4662467B2 - Sheet folding apparatus and sheet folding body manufacturing method using the same - Google Patents

Description

  The present invention relates to a method for manufacturing a sheet folded body.

  A method for obtaining a corrugated sheet is known. For example, Patent Document 1 discloses that a strip (band-like material) is pressed by a pressing device against a guide head provided with grooves that run parallel or inclined to each other, and the strip is pressed into the grooves to form a corrugated shape. A method of manufacturing a web is described. Further, Patent Document 2 includes a receiving-side roll provided with a concave groove along the outer peripheral portion, and a slit-side roll provided with a protrusion loosely inserted into the concave groove along the outer peripheral surface. A corrugated sheet manufacturing apparatus is described in which a corrugated sheet member is obtained by sandwiching a sheet member between the strips.

Special table flat 10-506333 JP 2002-144455 A

  However, the above technique is intended to obtain a corrugated sheet having a shallow folding width (wave height), and if the sheet is processed into a wide folding width (for example, a folding width of more than 10 mm), the sheet has a large amount. Stress is applied, wrinkles are generated on the sheet, and the sheet may be cut.

  Accordingly, an object of the present invention is to provide a sheet folded body manufacturing method and a sheet that can be stably obtained by folding the sheet without causing wrinkles or damage to the sheet. An object of the present invention is to provide a sheet folding apparatus that can be folded stably without causing wrinkles or damage.

  The present invention relates to a sheet including a trapezoidal inclined guide, an upper vertical guide having an inclined edge, and lower vertical guides disposed on both sides of the vertical guide in a direction orthogonal to the sheet conveying direction. In the folding device, a belt-like sheet is supplied onto the inclined surface of the inclined guide, and the sheet is folded along both side edges of the inclined guide while being conveyed along the inclined surface. The object is achieved by providing a method for manufacturing a sheet folded body, which is further folded by the upper and lower vertical guides to obtain a folded sheet.

  The present invention also includes a trapezoidal inclined guide and a plurality of vertical guides arranged in the vicinity of the inclined guide, and a belt-like sheet supplied on the inclined surface of the inclined guide is provided along the inclined surface. The sheet is folded along both side edges of the inclined guide while being conveyed, and the sheet thus folded is further folded by the plurality of vertical guides to form a folded body of the sheet. The object is achieved by providing a sheet folding apparatus.

According to the sheet folded body manufacturing method of the present invention, the sheet folded body can be stably manufactured by folding the sheet without causing wrinkles or damage to the sheet.
According to the sheet folding apparatus of the present invention, the sheet can be stably folded without causing wrinkles or damage to the sheet.

The present invention will be described below based on preferred embodiments with reference to the drawings.
FIG. 1 is a perspective view showing a main part of an embodiment of a sheet folding apparatus of the present invention. FIG. 2 is a view showing a state in which the sheet is folded using the folding device shown in FIG. 1, and FIG. 2 (a) schematically shows the state of the folding device shown in FIG. FIG. 2B schematically shows a state in which the folding device of FIG. 1 is viewed from the side. FIG. 3 shows the arrangement of the vertical guides in the folding apparatus shown in FIG. 1 as viewed from the downstream side in the sheet conveying direction, and FIG. 4 shows the arrangement of the vertical guides in the folding apparatus of FIG. Details are shown.

As shown in FIG. 1, the folding device 1 includes a trapezoidal inclined guide 10 and a plurality of vertical guides 21 to 24 arranged in the vicinity of the upper edge portion 12 side of the inclined guide 10. The belt-like sheet 3 continuously conveyed by the conveying device and supplied onto the inclined surface 11 of the inclined guide 10 is conveyed along the inclined surface 11 and along the side edges 14 and 14 of the inclined guide 10. The sheet 3 that has been bent and bent in such a manner is further bent by a plurality of vertical guides 21 to 24 to become a folded body 3 ′ of the sheet 3.
The folded body 3 ′ is formed with at least one valley fold 31 and mountain folds 32, 32 on both sides thereof. In this embodiment, the mountain folds 32, 32 on both sides of the valley fold 31 are formed. A foldable body 3 ′ having valley folds 33, 33 on the outer side of each is manufactured.

The folding device 1 will be described in more detail.
The inclined guide 10 has a flat plate shape with an isosceles trapezoidal shape in plan view, and corresponds to an upper edge portion 12 corresponding to the upper base of the trapezoid, a lower edge portion 13 corresponding to the lower base of the trapezoid, and a hypotenuse of the trapezoid. And left and right side edges 14, 14. The trapezoid is a trapezoid whose lower base is longer than the upper base.
As shown in FIG. 2A, the length L1 of the upper edge portion 12 of the inclined guide 10 is narrower than the width W of the sheet 3 supplied to the folding device 1, and the length of the lower edge portion 13 of the inclined guide 10 is set. L2 is wider than the width W of the sheet 3. Depending on the shape of the inclined guide 10 and the angle with the reference plane S to be described next, the sheet 3 is bent along the side edges 14 and 14 of the inclined guide 10 while being conveyed along the inclined guide 10. .

  The inclination guide 10 is fixed in a state that forms a predetermined angle with respect to the reference plane S by a support mechanism (not shown). As shown in FIG. 2B, the reference surface S is parallel to the conveyance direction P of the folded body 3 ′ of the sheet 3 and the upper edge portion 12 of the inclined guide 10 (one end 12 a in the longitudinal direction of the upper edge portion 12). And a straight line passing through the other end 12b) are also parallel planes. The conveyance direction P of the folded sheet 3 'is the position of the inner portions 32a, 32a of the fold lines of the mountain folds 32, 32 formed on both sides of the valley fold 31 formed by folding by the vertical guide 21. The standard. The inner portions 32 a and 32 a of the folding lines of the mountain fold portions 32 and 32 are portions where the upper edge portions 22 a and 22 a of the lower vertical guides 22 and 22 located on both sides of the vertical guide 21 are in contact.

The inclined guide 10 (specifically, the inclined surface 11) is relative to an inclination angle β with respect to the reference surface S (see FIG. 2B) and a straight line L parallel to the moving direction P of the seat 3 on the inclined surface 11. The fact that the inclination angle α (see FIG. 1) of the side edges 14 and 14 of the inclined guide 10 satisfies the relationship of the following formula (1) is stable without causing wrinkles or damage to the seat 3. From the viewpoint of realizing the folding, it is particularly preferable that the relationship of sin β = tan α is satisfied from the same viewpoint. In the present embodiment, the straight line L is orthogonal to the upper edge portion 12 of the inclined guide 10 or its extension line.
tan (α−10) ° <sin β <tan (α + 10) ° (1)
However, (α + 10) ° ≦ 45 °

  The inclination angle β of the inclination guide 10 is from the viewpoint of preventing the formation of a stable folded state and the generation of a large resistance (stress) between the sheet and the guide to damage or break the sheet. It is preferable to satisfy the above formula (1).

  The inclination angle β of the inclination guide 10 is normally more than 0 ° and not more than 90 °, but is preferably not less than 10 ° and not more than 50 ° from the viewpoint of preventing the sheet 3 from being wrinkled or damaged, and is not less than 15 °. More preferably, it is 30 ° or less.

The inclination angle α of the side edge portions 14 and 14 of the inclined guide 10 is preferably 10 ° or more and 40 ° or less from the viewpoint of realizing stable folding without causing wrinkles or damage to the seat 3. More preferably, the angle is 15 ° or more and 30 ° or less.
The length L1 (see FIG. 2A) of the upper edge portion 12 of the inclined guide 10 forms a folded body 3 ′ of the sheet 3 having a large folding width while preventing the sheet 3 from being wrinkled or damaged. From the viewpoint, the folding width W1 of the sheet 3 (see FIG. 2B) is preferably 1 to 3 times, more preferably 1.6 to 2.4 times, and particularly preferably 2.0 times. is there.
The folding width W1 of the sheet 3 is the distance between the inner part 31a of the fold line of the valley fold part 31 and the inner parts 32a, 32a of the fold lines of the mountain fold parts 32, 32 in the folded body 3 ′ of the sheet 3. is there. When the folding width of one mountain fold 32 is different from the folding width of the other mountain fold 32, the average value thereof is taken as the folding width of the sheet 3. According to this embodiment, the folding width W1 of the sheet can be set to about 15 to 30 mm, for example.

In addition, the length L2 (see FIG. 2A) of the lower edge portion 13 of the inclined guide 10 is preferably wider than the width obtained by multiplying the folding width W1 of the sheet 3 by the number of folds.
Here, the number of folds refers to the number of fold lines formed in the folded body 3 ′ of the sheet, and as shown in FIGS. 2B and 3, in the present embodiment, the sheet 3 is moved in the width direction. Therefore, the number of folds is five.

  As shown in FIG. 3, the plurality of vertical guides 21 to 24 in the folding device 1 are arranged in a direction (Y direction in FIG. 3) perpendicular to the conveyance direction of the sheet 3 (X direction in FIG. 2A). (Also simply referred to as “Y-direction”) and are arranged at different positions, and a space is provided between adjacent vertical guides. Although the space | interval of the Y direction between adjacent vertical guides can be suitably determined according to the thickness, rigidity, etc. of the sheet | seat 3, the sheet | seat 3 is an absorption sheet mentioned later, for example, and the thickness is 0.1-0.5 mm. In this case, the thickness is preferably about 0.5 to 1.5 mm.

As shown in FIG. 3, the folding device 1 includes, as a plurality of vertical guides 21 to 24, upper vertical guides 21, 23, 23 fixed to an upper support portion 25 located above the conveyance path of the sheet 3, and The lower vertical guides 22, 22, 24, 24 fixed to the lower support portion 26 located below the conveyance path of the sheet 3 are provided. The upper vertical guides 21, 23, 23 and the lower vertical guides 22, 22, 24, 24 are alternately arranged in the Y direction. Further, both the vertical guides 21 to 25 are perpendicular to the reference plane S.
The upper vertical guides 21, 23, 23 and the lower vertical guides 22, 22, 24, 24 are in a direction perpendicular to the reference plane S (hereinafter, this direction is the height direction, the position in the height direction). Are also arranged so that the portions of a predetermined width from the front end overlap each other.

As shown in FIG. 4B, the vertical guide 21 is a flat plate having a pentagonal shape when viewed from the side, and the arrangement position in the Y direction is that of the upper edge portion 12 of the inclined guide 12 as shown in FIG. It is almost coincident with the center position.
The vertical guide 21 has an inclined edge 21 a that is inclined with respect to the transport direction P of the sheet 3 and the reference surface S. The inclined edge portion 21a of the vertical guide 21 has an upstream end portion 21b (hereinafter also referred to as an upper end portion 21b) higher than the height position of the upper edge portion 12 of the inclined guide 10, and is downstream in the sheet conveying direction. The side end 21c (hereinafter also referred to as the lower end 21c) is at a position lower than the height position of the upper edge 12 of the inclined guide 10. Further, the upper end portion 21b of the inclined edge portion 21a is located upstream of the position of the upper edge portion 12 of the inclined guide 10 in the sheet conveying direction (X direction in FIG. 2, hereinafter also referred to as X direction). The lower end portion 21c is located on the downstream side in the sheet conveying direction with respect to the position of the upper edge portion 12 of the inclined guide 10 in the sheet conveying direction (X direction).
In the present embodiment, the difference in height between the upper edge portion 12 of the inclined guide 10 and the lower end portion 21c of the inclined edge portion 21a is equal to the folding width W1 of the sheet 3.

The inclination edge 21a of the vertical guide 21 preferably has an inclination angle γ (see FIG. 2B) with respect to the reference surface S close to the inclination angle β of the inclination guide 10, but the optimum value depends on the sheet material. Different. Specifically, a preferable range of the angle γ is (β−15) ° ≦ γ ≦ β.
In the present embodiment, the inclined edge portion 21a of the vertical guide 21 is linearly formed over the entire region between the upper and lower end portions 21b and 21c. Instead, only a portion having a predetermined width from the lower end portion 21c is formed. It is a straight line, and the other part has another shape such as a straight line having a different inclination angle from the straight line part or an arc shape whose height position gradually decreases as it approaches the straight line part. May be. In such a case, it is preferable that the linear portion having a predetermined width from the lower end portion 21c has the inclination angle γ described above.

As shown in FIG. 4 (b), the vertical guides 22 and 22 are made of a flat plate having a rectangular shape when viewed from the side. As shown in FIG. 4 (a), a pair of symmetrically arranged vertical guides 21 on both sides. Has been.
In the Y direction, the vertical guide 22 is disposed in a range where the upper edge portion 12 of the inclined guide 10 exists (between the position of one end and the other end in the longitudinal direction of the upper edge portion 12). The vertical guide 22 is disposed such that the bent portion of the sheet 3 bent along the side edge portion 14 of the inclined guide 10 contacts the upper edge portion 22 a of the vertical guide 22. The upper edge portion 22a of the vertical guide 22 is substantially parallel to the conveyance direction P of the folded body 3 ′, and the height position of the upper edge portion 22a is at the height position of the upper edge portion 12 of the inclined guide 10. It is almost coincident.

The pair of vertical guides 22 and 22 have a mutual separation distance L3 (see FIG. 4A) of 30% or less of the length L1 of the upper edge portion 12 on the basis of the positions of the opposing surfaces. More preferably, it is not less than the thickness of the vertical guide 21 and not more than 15% of the length L1. Further, the position in the X direction of the upstream end 22b of the upper edge portion of each of the pair of vertical guides 22 and 22 is the position in the X direction at the point where the extension lines of the both side edges 14 and 14 of the inclined guide 10 intersect each other. And at the same position.
The vertical guide 22 is disposed at a position slightly shifted from the vertical guide 21 on the downstream side in the sheet conveying direction. Specifically, the upstream end 22 b in the X direction of the upper edge 22 a of the vertical guide 22 is disposed so as to be substantially the same position as the position of the lower end 21 c of the vertical guide 21.

As shown in FIG. 4B, the vertical guides 23 and 23 are formed of a flat plate having a rectangular shape in a side view. The vertical guides 23 and 23 are disposed further outside the vertical guides 22 and 22, respectively. As shown in FIG. 4A, a pair of vertical guides 23 and 23 are symmetrically arranged on both sides of the vertical guide 21 as a center.
The vertical guide 23 is disposed such that the lower edge portion 23 a contacts the sheet 3. The lower edge portion 23a of the vertical guide 23 is substantially parallel to the conveyance direction P of the folded body 3 ′, and the height position of the lower edge portion 23a is the lower end portion 21c of the inclined edge portion 21a of the vertical guide 21. It almost matches the height position.
The vertical guide 23 is disposed at a position slightly shifted downstream in the sheet conveying direction from the vertical guide 21 in the X direction. More specifically, the X-direction upstream end 23b of the lower edge 23a of the vertical guide 23 is substantially the same position as the lower end 21c of the inclined edge 21a of the vertical guide 21, and the X-direction downstream end 23c is arranged at a position downstream of the vertical guide 22.

As shown in FIG. 4B, the vertical guides 24, 24 are formed of a flat plate that is rectangular in side view. The vertical guides 24 and 24 are disposed further outside the vertical guides 23 and 23, respectively. As shown in FIG. 4A, a pair of vertical guides 24 and 24 are also symmetrically arranged on both sides of the vertical guide 21 as a center.
The vertical guide 24 is disposed so that the surface of the sheet 3 that is directed toward the center in the width direction is in contact with the sheet 3. The height position of the upper edge portion 24 a of the vertical guide 24 is higher than the height position of the lower end portion 21 c of the inclined edge portion 21 a of the vertical guide 21. The upper edge portion 24a of the vertical guide 24 is substantially at the same height as the upper edge portion 12 of the inclined guide 10, and the upper edge portion 24a is parallel to the sheet conveyance direction P. The sheet 3 does not slidably contact the upper edge 24a. When the upper vertical guide is disposed further outside the vertical guide 24 and the number of folding sheets is increased, the sheet 3 is brought into contact with the upper edge portion 24a of the vertical guide 24.
The vertical guide 24 is disposed at a position shifted in the downstream direction in the sheet conveying direction from the vertical guide 23 in the X direction. More specifically, the end 24b on the upstream side in the X direction of the vertical guide 24 is substantially the same position as the end 22c on the downstream side in the X direction of the vertical guide 22, and the downstream end 24c in the X direction is on the vertical guide. It is arrange | positioned so that it may become a downstream position rather than 23.

  The folding device 1 includes a mechanism (not shown) that displaces the upper support 25 in the height direction (Z direction in FIG. 4), and integrally displaces the upper vertical guides 21, 23, and 23 up and down. The folding width W of the sheet 3 (see FIG. 4B) can be adjusted. Further, the folding device 1 includes a mechanism (not shown) that integrally moves the upper support 25 and the lower support 26 in the X direction in FIG. 4B, and includes vertical guides 21 to 25 and an inclined guide. 12 is adjustable.

  The folding device 1 described above is used in an embodiment of the method for producing a sheet folded body of the present invention. In order to use the folding device 1 to fold the sheet 3 to obtain the sheet folded body 3 ′, the overlapping width of the upper vertical guides 21, 23, 23 and the lower vertical guides 22, 24 is set to the target sheet 3. In this state, the sheet 3 is introduced onto the inclined surface 11 of the inclined guide 10 and passed between the upper vertical guide and the lower vertical guide. Is pulled out by a pulling means 5 comprising a pair of nip rolls 51, 51 and the like.

The sheet 3 supplied onto the inclined guide is bent along the side edges 14 and 14 of the inclined guide 10 while being conveyed along the inclined surface 22 of the inclined guide 10. Then, the inclined edge portion 21a of the vertical guide 21 comes into contact with the sheet 3 reaching the upper edge portion 12 of the inclined guide 10 from above, and the sheet 3 is conveyed in this state, whereby the central portion of the sheet 3 is It is pressed by the inclined edge 21 and folded into a valley fold state. At the time of this folding, there are bent portions that are bent along the side edge portions 14 and 14 of the inclined guide 10 on both sides thereof, and the bent portions are located slightly downstream of the vertical guides 22 and 22. Since the upper edge portions 22a and 22a are supported from below, the portion where the inclined edge portion 21a of the vertical guide 21 abuts is smoothly folded into a valley shape to form a valley fold portion 31 and is vertical. The portions where the upper edges 22a and 22a of the guides 22 and 22 are in contact with each other are smoothly bent into a mountain shape to form mountain folded portions 32 and 32.
Furthermore, the lower edge portion 23a of the vertical guide 23 abuts on the outer side of the bent portion along the side edge portions 14 and 14 of the inclined guide 10 in the sheet 3, and the vertical guide 24 further abuts on the outer side thereof, thereby The valley folds 33, 33 are smoothly formed on the outer sides of the folds 32, 32, respectively.

In the sheet folding method of the present embodiment, the drawing means 5 including a pair of nip rolls 51 and 51 is arranged downstream of the arrangement position of the vertical guides 21 to 25, and the sheet 3 is pulled by the drawing means 5. The sheet 3 is folded along both side edges 14 and 14 of the inclined guide 10, and the sheet 3 is introduced between an upper vertical guide and a lower vertical guide to be folded in a bellows shape. A pair of guide rolls 4 and 4 are arranged between the vertical guides 21 to 25 and the pulling means 5, and a pair of guide rolls with respect to the folded sheet 3 (sheet folded body 3 ′). A twist of 90 degrees is applied between 4, 4 and the drawing means 5.
The drawing speed of the sheet folded body 3 ′ by the drawing means 5 (same as the peripheral speed of the nip roll 41) is the conveying speed of the sheet 3 supplied to the inclined guide 10 (in the example shown in FIG. 2B), 90% to 100% of the circumferential speed of the roll 5 disposed immediately before is preferable from the viewpoint of giving an appropriate tension to the sheet 3 and realizing a beautiful fold, and 96% to 99% from the same viewpoint. It is more preferable that

  In the folding device and the sheet folding body manufacturing method of the present embodiment, various known sheets can be folded. Examples of the sheet 3 to be folded include non-woven fabrics, folding cloths, knitted cloths, resin films, laminated sheets obtained by laminating two or more of these (same or different), laminated sheets of these and fiber webs, two or more layers And the like, in which functional particles such as a superabsorbent polymer and activated carbon are sandwiched between layers of the laminated sheet.

The folding device and the sheet folding body manufacturing method of the present embodiment are suitable for folding an absorbent sheet formed by holding a superabsorbent polymer in a nonwoven fabric.
The nonwoven fabric may be a single layer or multiple layers (two or more layers), and the superabsorbent polymer is held in a state where the superabsorbent polymer is buried between the fibers of the nonwoven fabric. It is also possible that the superabsorbent polymer is sandwiched between two fiber layers. The absorbent sheet having a structure in which a superabsorbent polymer is sandwiched between two fiber layers is obtained by sandwiching a superabsorbent polymer between two separate fiber webs and / or non-woven fabrics. After the superabsorbent polymer was sprayed in the region of the predetermined width in the center in the width direction of the belt-shaped sheet, the superabsorbent polymer was sprayed in a pair of left and right regions outside the region where the superabsorbent polymer was sprayed. Examples thereof include one in which two fiber layers are formed by folding on the region.

  When the absorbent sheet to be folded is a single layer or multilayer structure nonwoven fabric (whether or not the superabsorbent polymer is held), the constituent fiber is preferably a hydrophilic fiber, and the hydrophilic fiber includes pulp. Originally hydrophilic fibers such as fibers, rayon and cotton, and polypropylene, polyethylene, polyester (such as PET) and the like are originally hydrophobic synthetic fibers. Examples thereof include those made hydrophilic by a hydrophilic treatment. The synthetic fiber may be a composite fiber (side-by-side type, core-sheath type, etc.) composed of two or more resin components. In addition to hydrophilic fibers, hydrophobic fibers may be mixed within a range that does not substantially impair the absorbability. The ratio of the hydrophilic fiber in the fiber material is preferably more than 50% by mass, and more preferably 70 to 100% by mass.

  When the sheet 3 to be folded is an absorbent sheet, the obtained sheet folded body 3 ′ is preferably used as an absorbent body for absorbent articles such as sanitary napkins, panty liners (origami sheets), incontinence pads, disposable diapers and the like. be able to.

The absorbent article 6 shown in FIG. 5 includes a liquid-permeable top sheet 61, a liquid-impervious (including poorly liquid-permeable) back sheet 62, and a folded body 3 ′ of the sheet 3 as an absorber. The folding body 3 ′ is arranged at the center in the width direction of the absorbent article 6.
The absorbent article shown in FIG. 5 (a) uses a sheet folded body 3 ′ alone as an absorbent body, and the absorbent article shown in FIG. 5 (b) includes a sheet folded body 3 ′ and pulp fibers. Etc., and a laminated fiber product 63 (may be a mixed fiber material containing a superabsorbent polymer) is used as an absorbent body. The part indicated by reference numeral 64 in FIG. 5B is an embossed part for joining the top sheet 61 and the piled product 63. When the sheet folded body 3 ′ is used as an absorbent body, the cushioning property in the thickness direction of the sheet 3 before folding is added with mechanical elastic force due to folding in a bellows shape, so that the absorbent body which is soft and rich in cushioning properties is obtained. can get.

In the folding device and the sheet folding body manufacturing method of the present embodiment, the sheet folded body 3 ′ obtained by the folding device 1 is rotated 90 degrees around an axis parallel to the transport direction P as described above. Then, the orientation of the upper and lower surfaces of the folded body 3 ′ is changed in the horizontal direction, and then the folded body 3 ′ is subjected to a joining process by a heat seal device (pressurizing device) at a predetermined interval, and the layers of the folded body 3 ′ are Are joined. As a result, a sheet folded body having a stable structure can be obtained.
The heat seal apparatus includes a convex roll 71 having a convex portion 72 for pressurization on the peripheral surface, and a smooth roll 73 that narrows the folded body 3 ′ between the convex portion 72. As the pressurizing device, a device that only pressurizes without applying heat may be used. Further, the convex portion 72 may be discontinuous in the axial length direction instead of being continuous in the axial length direction. The joint part partially formed on the sheet folded body 3 ′ by such joining processing, for example, when used as an absorbent body of an absorbent article, near the front end and / or the end in the longitudinal direction of the absorbent body. Located near the edge.

The present invention is not limited to the above embodiment.
For example, the number of folds of the sheet 3 is not limited to 5, and a folded body having only a valley fold portion folded by the vertical guide 21 and a mountain fold portion on both sides thereof can be manufactured. Further, by arranging an arbitrary number of upper vertical guides and lower vertical guides alternately on the outer side, a folded body having six or more folds can be manufactured. The present invention is suitable for manufacturing a folded body 3 ′ having 4 to 8 folds. Moreover, this invention can perform the folding process of a sheet | seat with respect to the sheet conveyed at the speed of 0-300 m / min, for example.

FIG. 1 is a perspective view showing a main part of an embodiment of a sheet folding apparatus of the present invention. FIG. 2 is a diagram illustrating a state in which a sheet is folded using the folding device illustrated in FIG. 1, and FIG. 2A is a schematic overhead view illustrating a state in which the folding device illustrated in FIG. 1 is viewed from above. FIG.2 (b) is a typical side view which shows the state which looked at the folding apparatus of FIG. 1 from the side. FIG. 3 is a layout diagram illustrating a state in which the vertical guide in the folding device illustrated in FIG. 1 is viewed from the downstream side in the sheet conveyance direction. FIG. 4 is a diagram showing details of the arrangement of the vertical guides in the folding device of FIG. 1, FIG. 4 (a) is a diagram showing the arrangement in a direction parallel to the reference plane, and FIG. It is the sectional view on the AA line of Fig.4 (a). FIG. 5 is a diagram illustrating an example of the use of the sheet folded body, and FIGS. 5A and 5B are cross sections along the width direction of the absorbent article including the sheet folded body as an absorbent body, respectively. It is a typical sectional view showing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Folding device 10 Trapezoid-shaped inclination guide 12 Upper edge part of inclination guide 14 Side edge part of inclination guide 21, 23 Upper vertical guide 22, 24 Lower vertical guide 3 Sheet 3 'Sheet folding body

Claims (5)

A folding device for a sheet , which includes a trapezoidal inclined guide and a plurality of vertical guides arranged in the vicinity of the inclined guide, and folds the sheet in the width direction while conveying a belt-like sheet ,
The inclined guide has a trapezoidal shape,
The inclined guide has an upper edge corresponding to the upper base of the trapezoid, a lower edge corresponding to the lower base longer than the upper and lower sides, and left and right side edges corresponding to the hypotenuse of the trapezoid. The upper edge portion, the lower edge portion, and the left and right side edge portions, and the lower edge portion is an upstream side in the sheet conveyance direction, and the upper edge portion is the sheet. Is located downstream of the transport direction of
The inclined surface of the inclined guide is inclined with respect to a reference surface that is a plane parallel to the conveyance direction of the folded sheet and parallel to the upper edge portion of the inclined guide;
As the plurality of vertical guides, an upper side which is a surface side opposite to the surface which is directed to the inclined surface side with respect to the belt-like sheet which is supplied to the inclined surface and passes the position of the upper edge portion An upper vertical guide having an inclined edge portion that abuts against and presses the sheet, and a lower portion that is disposed on both sides of the vertical guide and contacts the sheet after the inclined edge portion abuts from below And at least a vertical guide,
The upper vertical guide and the lower vertical guide are both plate-shaped, and are provided so that both surfaces thereof are along the sheet conveyance direction and perpendicular to the reference plane.
In the upper vertical guide, the inclined edge portion is disposed close to the upper edge portion of the inclined guide, and the lower end portion which is the end portion on the downstream side in the sheet conveyance direction at the inclined edge portion is the reference In the height direction perpendicular to the surface, is located at a position lower than the height position of the upper edge of the inclined guide,
The lower vertical guide is disposed within a range in which the upper edge portion of the inclined guide exists in a direction orthogonal to the sheet conveyance direction, and in the height direction, the lower vertical guide The sheet folding apparatus , wherein a height position of the upper edge portion substantially coincides with a height position of the upper edge portion of the inclined guide . An inclination angle β of the inclined surface of the inclined guide with respect to the reference surface and an inclination angle α of both side edges of the inclined guide with respect to a straight line L parallel to the moving direction of the sheet on the inclined surface (see FIG. 1). preparative is set so as to satisfy the relationship of the following formula (1), the sheet folding apparatus according to claim 1.
tan (α−10) ° <sin β <tan (α + 10) ° (1) Further, a vertical guide above the rectangular in side view is provided outside in the direction perpendicular to the sheet conveying direction of the lower vertical guide, and the height position of the lower edge of the vertical guide above the rectangular in side view is The sheet folding apparatus according to claim 1, wherein the sheet folding device substantially coincides with a height position of a lower end portion of the inclined edge portion of the upper vertical guide having the inclined edge portion. A sheet folding device manufacturing method for manufacturing a sheet folding body, wherein the sheet folding device according to any one of claims 1 to 3 is used to fold the sheet in a width direction while conveying a belt-like sheet. And
A belt-like sheet having a width longer than the length of the upper edge portion of the inclined guide is supplied to the inclined surface of the inclined guide, and the both sides of the inclined guide are conveyed while the sheet is conveyed along the inclined surface. A method for manufacturing a sheet folded body, wherein the sheet is further folded by the upper and lower vertical guides after being folded along the section to obtain a folded sheet . The method for producing a sheet folded body according to claim 4 , wherein the belt-like sheet is an absorbent sheet.

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