JP6132193B2 - Absorbent article and manufacturing method thereof - Google Patents

Description

  The present invention relates to an absorbent article in which an uncomfortable feeling due to a step at an end of an absorbent body is reduced, and a method for manufacturing the same.

  Absorbent articles such as disposable diapers and sanitary napkins have a basic structure including an absorber that absorbs excreta, a front layer that covers the front side of the absorber, and a back layer that covers the back side of the absorber. The front and back layers are usually stretched and joined at least to the front and back of the absorber, and depending on the product, they are also extended and joined to the side, thereby forming flaps at the front and rear ends and both sides. (For example, see Patent Documents 1 and 2). And since an absorber has thickness more or less, the angle | corner on the edge part of an absorber appears on the surface, and comes to contact skin.

  In particular, when the absorbent body is cut at a predetermined length when the absorbent body is manufactured, the cut end portion is compressed and hardened, so that the corners on the end portion are also hard, and the wearer feels uncomfortable. become. In addition, the thickness of the absorber also contributes to an increase in discomfort.

  Even if such a problem is configured such that the surface of the absorber is flat in the product state as in Patent Document 1, for example, the corners of the absorber are present at the same position and do not appear as shapes on the surface. But there is no change in hitting the skin through the front layer.

JP 2006-320443 A JP 2007-260016 A

  Then, the main subject of this invention is to prevent that the corner | angular top on an absorber edge part hits skin.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In an absorbent article comprising an absorber that absorbs excrement, a front side layer that covers the front side of the absorber, and a back side layer that covers the back side of the absorber,
The absorber is formed by laminating a plurality of layers, and at least one of the front, rear, left, and right ends of the frontmost layer protrudes outside the backside layer, and the protruding portion is on the backside. The curved end is curved toward the
An absorbent article characterized by the above.

(Function and effect)
In the absorbent article of the present invention, since at least one of the front, rear, left and right ends of the absorbent body is curved toward the back side, the portion excluding the end portion is a portion that mainly contacts the skin, Since the corner of is located on the back side of the portion that touches the skin, it becomes difficult to hit or not touch the skin.
Further, in this way, when the absorber has a laminated structure and the end of the most front layer protrudes from the back layer and is bent to the back side, the curved end is surely formed in a desired position and shape. And the shape is easy to maintain.

<Invention of Claim 2>
The absorbent article according to claim 1, wherein the curved end portion is a cut end portion formed by cutting when the absorbent body is manufactured.

(Function and effect)
As described in the section of the prior art, when the absorbent body is cut at a predetermined length when the absorbent body is manufactured, the cut end portion is compressed and hardened, so the corner on the end portion is also hard. This will cause the wearer to feel uncomfortable. Therefore, the present invention is preferable in such a case.

<Invention of Claim 3 >
The absorbent article according to claim 1 or 2 , wherein the absorber has a thickness of 3 mm or more.

(Function and effect)
As described in the section of the prior art, the uncomfortable feeling due to the upper corners of the absorber increases as the absorber becomes thicker, and the discomfort is particularly remarkable when the thickness of the absorber is 3 mm or more. Therefore, the present invention is suitable for such a case.

<Invention of Claim 4 >
In an absorbent article comprising an absorber that absorbs excrement, a front side layer that covers the front side of the absorber, and a back side layer that covers the back side of the absorber,
At least one of the front, rear, left and right ends of the absorber is a curved end that is curved toward the back side,
Of the absorber, the curved end portion is not fixed to the back side layer, and a portion other than the curved end portion is fixed to the back side layer,
The curved end portion is formed by curving the end portion of the absorber toward the back side when the entire back side layer contracts more than the front side layer due to elasticity or heat.
An absorbent article characterized by the above .

(Function and effect)
By forming the curved end portion in this manner, the structure of the present invention can be easily manufactured without deforming the absorber or forming it into a curved shape. Whether or not the structure has such a curved end portion can be determined by the presence or absence of heat shrinkage and the difference in the amount of expansion / contraction between the front side layer and the back side layer.

Further, by providing such a non-fixed portion, the end portion can be selectively curved as a material for contracting the entire back side layer. That is, even if the entire backside layer tries to elastically contract, the portion where the absorber is fixed does not contract greatly due to the rigidity of the absorber, whereas the non-fixed portion of the absorber contracts greatly and curves suddenly. Become.

<Invention of Claim 5 >
An absorber that absorbs excrement, a front layer that covers the front side of the absorber, and a back layer that covers the back side of the absorber, and at least one of the front, rear, left, and right ends of the absorber are directed toward the back side A method of manufacturing an absorbent article having a curved curved end ,
Of the absorber, the portion that becomes the curved end portion is not fixed to the back side layer, and the portion other than the portion that becomes the curved end portion is fixed to the back side layer,
The entire back side layer is contracted more elastically or thermally than the front side layer, whereby the end of the absorber is curved toward the back side, thereby forming the curved end.
The manufacturing method of the absorbent article characterized by the above-mentioned.

(Function and effect)
The same effects as those of the invention of the fourth aspect are achieved.

  As described above, according to the present invention, there are merits such as a single release sheet and easy attachment work while preventing mis-attachment of the misalignment stopper.

It is a top view which shows the surface side of the expansion | deployment state of a pad type absorbent article. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is the schematic of a manufacturing flow. It is the schematic of a manufacturing flow. It is (a) principal part top view for demonstrating the bending principle of a curved edge part, (b) principal part sectional drawing of the expansion | extension state, (c) principal part sectional drawing of a contraction state. It is a top view which shows the back surface side of the expansion | deployment state of a pad type absorbent article. It is AA sectional drawing of FIG. It is the schematic of a manufacturing flow. It is sectional drawing equivalent to the AA cross section of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
(First form)
1 to 3 show a pad type absorbent article 200. This pad-type absorbent article 200 is assumed to be used by laying on the inner surface of an outer such as disposable diaper 1 or cloth underwear, and has a crotch portion C and an abdominal portion F extending on both front and rear sides thereof. And a back portion B. The “groin area” in the absorbent pad means a part corresponding to the crotch of the body at the time of use, and in most products, it is a central part in the front-rear direction and a part in the vicinity of the front and rear.

  The dimensions of each part can be determined as appropriate. For example, in the case of a product for adults, the total length L (length in the front-rear direction) can be about 450 to 630 mm, and the total width W can be about 135 to 320 mm. The length in the front-rear direction of the part C can be about 150 to 180 mm, the length in the front-rear direction of the ventral part F can be about 120-200 mm, and the length in the front-rear direction of the dorsal part B can be about 180-280 mm.

The pad type absorbent article 200 has a basic structure in which an absorber 23 is interposed between the inner surface of the liquid-impermeable sheet 21 and the liquid-permeable top sheet 22. Absorbent body 23 is basically made of a pile of pulp fibers (cotton pulp), an aggregate of filaments such as cellulose acetate, or a non-woven fabric, and is formed by mixing, adhering, etc. with a superabsorbent polymer as necessary. Can be used. The absorbent body 23 can be wrapped with a wrapping sheet 27 made of crepe paper, non-woven fabric, or the like, if necessary, such as when mixing highly absorbent polymer particles. Moreover, the shape of the absorber 23 can be an appropriate shape such as a rectangular shape or an hourglass shape having a narrow constricted portion in the middle in the front-rear direction. The fiber basis weight and the basis weight of the absorbent polymer in the absorbent body 23 can be appropriately determined. The fiber basis weight is preferably about 200 to 600 g / m ^2, and the basis weight of the absorbent polymer is about 100 to 300 g / m ^2. Is preferable.

  On the back side of the absorber 23, a liquid-impermeable sheet 21 is provided so as to protrude a predetermined length from the peripheral edge of the absorber 23. As the liquid-impermeable sheet 21, a sheet having moisture permeability can be used in addition to a polyethylene film or the like without impairing the water barrier from the viewpoint of preventing stuffiness. This water-impervious / breathable sheet is a microporous sheet obtained by, for example, melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching in a uniaxial or biaxial direction. Can be used.

  The outer surface (back surface) of the liquid-impermeable sheet 21 is covered with an exterior sheet 25 made of a nonwoven fabric or the like, but the exterior sheet 25 can be omitted as shown in FIG.

  The front side of the absorber 23 is covered with a top sheet 22. As the top sheet 22, a perforated or non-porous nonwoven fabric or a perforated plastic sheet is used. As the material fiber constituting the nonwoven fabric, synthetic fibers such as polyethylene or polypropylene, synthetic fibers such as polyester and amide, recycled fibers such as rayon and cupra, and natural fibers such as cotton can be used.

  At both ends in the front-rear direction of the pad-type absorbent article 200, the liquid-impermeable sheet 21, the exterior sheet 25, and the top sheet 22 are respectively attached to the front and rear ends of the absorbent body 23 so as to extend to the front and rear sides. An end flap portion EF that does not exist is formed.

  At both side portions of the pad type absorbent article 200, the side portions of the liquid-impermeable sheet 21 and the exterior sheet 25 wrap around the side edges of the absorbent body 23 to reach the front side of the absorbent body 23, and the side surface of the top sheet 22. The three-dimensional gathers 24 are provided thereon. Including these, the bonded portion of the material can be formed by hot melt adhesive, heat sealing, or ultrasonic sealing, and is indicated by a dot pattern in the figure.

  The three-dimensional gather 24 is formed by using a gather sheet 24s folded into a two-layer structure and an elongated elastic member, a root portion 24x joined to the side surface of the diaper, and a main body portion extending from the root portion. 24c, an inferior part 24d formed by fixing both front and rear ends of the main body part 24c in a lying state, and a free part 24f formed by unfixing a part between the inclining parts 24d in the main body part. The elongated elastic member 24G is fixed in a gathered sheet 24s at the tip of the free portion 24f in a state of extending in the front-rear direction. In such a three-dimensional gather 24, the free part rises with respect to the inner surface of the diaper (in the illustrated form, the surface of the top sheet 22) by the contraction force of the elongated elastic member 24G. As a material for the gather sheet 24s, a plastic sheet or a melt-blown nonwoven fabric can be used, but from the viewpoint of touch to the skin, a nonwoven fabric that is water-repellent treated with silicon or the like is preferably used. Further, as the elongated elastic member 24G, styrene rubber, olefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicon, polyester, which are formed in a thread shape, a string shape, a belt shape, or the like. For example, a commonly used material can be used.

  Characteristically, as shown in FIG. 2, the front and rear end portions of the absorber 23 are curved end portions 23 </ b> R that are curved toward the back side. Although not shown, the left and right end portions (side edge portions) can be used as the curved end portion 23R together with or in place of the front and rear end portions of the absorber 23. In particular, when the absorbent body 23 is cut at a predetermined length when the absorbent body 23 is manufactured, the cut end portion is compressed and hardened, and the corners on the end portion are hard, resulting in a feeling of strangeness for the wearer. Therefore, it is desirable that such a cut end portion be the curved end portion 23R. Also, the uncomfortable feeling due to the corners on the end of the absorbent body 23 increases as the absorbent body 23 is thicker. In particular, when the thickness of the absorbent body 23 is 3 mm or more, the uncomfortable feeling is remarkable. Therefore, particularly in the case of the absorber 23 having a thickness (apparent thickness) of 3 mm or more, it is desirable to provide the curved end portion 23R.

  The degree of curvature of the curved end portion 23R can be appropriately changed as long as the end surface is not perpendicular to the back surface, but the end surface is preferably 45 degrees or less with respect to the back surface, and particularly as illustrated. More preferably, the end surface is bonded to the liquid-impermeable sheet 21 and is substantially parallel to the back surface. In addition, the length of the curved end portion 23R in the bending direction can be determined as appropriate, but in the normal case, it is preferably about 3 to 10 mm.

  As shown in FIG. 10, the absorber 23 may be curved at its end as a single layer structure (not shown), but the curved end 23R can be reliably formed in a desired position and shape, and its shape As shown in the figure, the absorber 23 is formed by laminating a plurality of layers (in the illustrated example, a two-layer structure of an upper layer 23B and a lower layer 23B), and before and after the frontmost layer 23B. It is preferable that the curved end portion 23R is formed by protruding at least one of the left and right ends outward from the back layer 23A and bending the protruding portion toward the back side.

  As described above, when the end portion of the absorber 23 is the curved end portion 23R curved toward the back side, the portion excluding the end portion of the absorber 23 mainly comes into contact with the skin, and the curved end portion 23R Since the upper corner is located on the back side of the portion that touches the skin, it becomes difficult to hit or does not hit the skin.

  The method for forming the curved end portion 23R is not particularly limited, and the absorber 23 may be deformed or formed into a curved shape. However, as described below, a more easily manufactured form and its manufacturing method I also propose. That is, FIG.4 and FIG.5 has shown an example of the manufacturing method of a pad type disposable diaper, and the packaging sheet 27 by which the absorber lower layer 23A of the predetermined shape sequentially shape | molded by the 1st fiber drum 50 is supplied separately. After the absorbent upper layer 23B, which is arranged at a predetermined interval on the upper side and is continuously formed by the second stacking drum 51, is sequentially arranged on the lower layer 23A in a continuous state, the packaging sheet 27 is wound up to the upper layer 23B. Then, the individual absorbing elements 23 and 27 are manufactured by being cut at predetermined intervals in the line flow direction by the cutting device 52. Therefore, the front and rear ends of the absorber upper layer 23B are formed by cutting, and the front and rear ends of the upper layer 23B protrude from the front and rear ends of the lower layer 23A. In addition, what is necessary is just to omit the 2nd fiber drum 51, when employ | adopting the single layer structure of the absorber 23. FIG.

  The laminated sheet is supplied with the top sheet 22 from the front side and the exterior sheet 25 and the liquid-impermeable sheet 21 from the back side with respect to the absorbent elements sequentially manufactured in this manner, and on the liquid-impermeable sheet 21. Further, the absorbent elements 23 and 27 are fixed by a joining means such as a hot melt adhesive, and the top sheet 22 and the liquid-impermeable sheet 21 are joined around the absorbent body 23. At this time, when the exterior sheet 25 is formed of a stretchable nonwoven fabric that elastically expands and contracts, or when the exterior sheet 25 is omitted, the liquid impermeable sheet 21 is formed of an elastic stretchable material, or the exterior sheet 25 and the liquid impermeability are formed. An elastic member such as thread rubber is fixed between the sheets 21 or the outer sheet 25 in a two-layer structure and stretched in the front-rear direction, and the back side layer elastically stretchable in the front-rear direction is transported on the production line. The absorbent body 23 is fixed to the surface in a state of being stretched by the tension. Moreover, in order to make it the structure shown in FIGS. 1-3, the junction part of the side sheet | seat of the absorber 23 and the liquid-impermeable sheet | seat 21 is turned up front side, and is fixed with a hot-melt-adhesive.

  Next, solid gathers (not shown) are attached to both sides of the surface as necessary, and then cut by the cutting device 53 at a predetermined interval in the line flow direction, whereby individual disposable diapers 200 are manufactured. Then, the line tension (tension) is released along with the cutting into the individual diapers, so that the back layer is automatically changed from the state shown in FIGS. 6 (a) and 6 (b) as shown in FIG. 6 (c). 21 and 25 contract more than the top sheet 22, and as a result, the front and rear ends of the absorbent body 23 are curved toward the back side to form a curved end 23R. In particular, when the absorber 23 is fixed to the backside layers 21 and 25, as can be seen from the application portion of the hot melt adhesive HM shown in FIG. If not fixed to 21 and 25, when the line tension is released, the entire back side layers 21 and 25 tend to elastically contract, but the portion to which the absorber 23 is fixed does not contract greatly due to the rigidity of the absorber 23. On the other hand, the non-fixed portion of the absorber 23 is greatly contracted and curved at a steep angle (in other words, the end portion is selectively curved). Of course, the back side layers 21 and 25 are configured to elastically expand and contract only the portion corresponding to the portion that becomes the curved end portion 23R of the absorbent body 23 (for example, an elastic member such as a thread rubber is fixed in an expanded state only in the portion). Also good.

  Thermal contraction can also be used as a technique that does not depend on elastic expansion and contraction. That is, instead of using the back-side layers 21 and 25 that elastically expand and contract as in the form shown in FIG. 5, the back-side layers 21 and 25 in the back-side layers 21 and 25, as shown in FIG. After fixing the heat-shrinkable material 29 to the corresponding site, the heat-shrinkable material 29 is thermally shrunk through a heating device 54 that blows warm air. As a result, the backside layers 21 and 25 are automatically contracted more than the top sheet 22 and, as a result, in a state after being cut into at least individual diapers, as shown in FIG. 7 and FIG. The front and rear ends are curved toward the back side to form a curved end 23R. The material of the back side layers 21 and 25 may be a heat shrink material. Others are the same as the case where the back side layers 21 and 25 which elastically expand and contract are used.

  The present invention is suitable for pad-type disposable diapers as described above, but can also be used for sanitary napkins, and also for other types of absorbent articles such as tape-type disposable diapers and pants-type disposable diapers. Is available.

  B: Dorsal side portion, C: Crotch portion, F: Ventral portion, 21 ... Liquid impervious sheet, 22 ... Top sheet, 23 ... Absorber, 23B ... Upper layer, 23A ... Lower layer, 23R ... Curved end, 24 ... solid gathers, 25 ... exterior sheets, 27 ... packaging sheets, 29 ... heat-shrinkable materials, 200 ... pad type absorbent articles.

Claims (5)

In an absorbent article comprising an absorber that absorbs excrement, a front side layer that covers the front side of the absorber, and a back side layer that covers the back side of the absorber,
The absorber is formed by laminating a plurality of layers, and at least one of the front, rear, left, and right ends of the frontmost layer protrudes outside the backside layer, and the protruding portion is on the backside. The curved end is curved toward the
An absorbent article characterized by the above.   The absorbent article according to claim 1, wherein the curved end portion is a cut end portion formed by cutting when the absorbent body is manufactured. The absorbent article according to claim 1 or 2 , wherein the absorber has a thickness of 3 mm or more. In an absorbent article comprising an absorber that absorbs excrement, a front side layer that covers the front side of the absorber, and a back side layer that covers the back side of the absorber,
At least one of the front, rear, left and right ends of the absorber is a curved end that is curved toward the back side,
Of the absorber, the curved end portion is not fixed to the back side layer, and a portion other than the curved end portion is fixed to the back side layer,
The curved end portion is formed by curving the end portion of the absorber toward the back side when the entire back side layer contracts more than the front side layer due to elasticity or heat.
An absorbent article characterized by the above . An absorber that absorbs excrement, a front layer that covers the front side of the absorber, and a back layer that covers the back side of the absorber, and at least one of the front, rear, left, and right ends of the absorber are directed toward the back side A method of manufacturing an absorbent article having a curved curved end ,
Of the absorber, the portion that becomes the curved end portion is not fixed to the back side layer, and the portion other than the portion that becomes the curved end portion is fixed to the back side layer,
The entire back side layer is contracted more elastically or thermally than the front side layer, whereby the end of the absorber is curved toward the back side, thereby forming the curved end.
The manufacturing method of the absorbent article characterized by the above-mentioned.

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