Disposable absorbent article and method of manufacturing the same

A disposable absorbent article comprises an outer cover, and an absorbent member attached to the skin facing side of the outer cover. The absorbent member includes an absorber. At least a crotch zone of the outer cover is subjected to a softening process for softening a material of the outer cover.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a disposable absorbent article and a method of manufacturing the same.

2. Description of the Background Art

A disposable absorbent article made of a material having poor flexibility is less likely to fit the shape of wearer's body and causes rough and uncomfortable feeling to the wearer's skin. Ensuring material flexibility is therefore an important issue. Particularly, the crotch zone of an absorbent article undergoes great changes in shape and the like before and after putting on the article, and further, includes an absorber that is likely to mainly cause the rough feeling. Therefore, ensuring the flexibility of the crotch zone is of particular importance.

Conventional disposable absorbent articles, however, do not take sufficient measures to ensure the flexibility of the crotch zone and the like.

SUMMARY OF THE INVENTION

The present invention has an object to provide a disposable absorbent article with improved flexibility at least in the crotch zone of an outer cover, and a method of manufacturing the same.

A first aspect of a disposable absorbent article according to the present invention comprises: an outer cover; and an absorbent member attached to the skin facing side of the outer cover, the absorbent member including an absorber. At least a crotch zone of the outer cover is subjected to a softening process for softening a material of the outer cover.

The softening process improves the flexibility of at least the crotch zone of the outer cover, which prevents particularly the crotch zone of the absorbent article from being less likely to fit the wearer's body and causing rough and uncomfortable feeling to the wearer's skin.

In a second aspect of the disposable absorbent article, in the disposable absorbent article according to the first aspect, a plurality of almost slit-like holes extending through the outer cover are provided in a portion of the outer cover having been subjected to the softening process.

The plurality of almost slit-like holes extending through the outer cover are created by the softening process. This effectively ensures the flexibility of material for the outer cover and achieves a high degree of breathability of material, thereby avoiding dampness.

In a third aspect of the disposable absorbent article, in the disposable absorbent article according to the first or second aspect, a portion of the outer cover subjected to the softening process is softened by application of blades of a cutter.

The softening process is achieved by applying the blades of the cutter, which effectively improves the flexibility of material with simple processing.

In a fourth aspect of the disposable absorbent article, the disposable absorbent article according to any one of the first to third aspects further comprises elastic members attached from along leg-side edges of the outer cover surrounding the wearer's left and right legs to the crotch zone. Part of the elastic members attached to the crotch zone is cut short to be weakened.

Part of the elastic members positioned in the crotch zone is weakened, which prevents the absorber from receiving an unnecessary force caused by the contractive forces of the elastic members and degrading in its absorptive function.

Further, the elastic members are attached continuously from along the left and right leg-side edges of the outer cover to the crotch zone, and part of the elastic members positioned in the crotch zone is weakened along with the softening process performed on the crotch zone of the outer cover, which can simplify the manufacturing steps of the absorbent article.

A first aspect of a method of manufacturing a disposable absorbent article according to the present invention is directed to a method of manufacturing a disposable absorbent article having an outer cover and an absorbent member attached to the skin facing side of the outer cover, the absorbent member including an absorber. The method comprises the steps of: a) softening at least a portion of a continuous material to be a crotch zone of the outer cover while transporting the continuous material in its longitudinal direction, the continuous member being a series of material for forming the outer cover and extending continuously in a lateral direction of the absorbent article; b) attaching the absorbent member to the continuous material; and c) cutting the continuous material, with the absorbent member attached thereto, into products.

The absorbent article can be manufactured at least with the crotch zone of the outer cover improved in flexibility by the softening process.

In a second aspect of the method of manufacturing a disposable absorbent article, in the method according to the first aspect, an elastic member is attached from along leg-side edges of the outer cover surrounding the wearer's left and right legs to the crotch zone. The method further comprises the step of d) attaching the elastic members continuously to the continuous material while transporting the continuous material in the longitudinal direction. In the step a), blades of a cutter are applied to at least a portion of the continuous material to be the crotch zone of the outer cover to thereby soften the portion, and part of the elastic members positioned in the portion is cut short to be weakened.

The absorbent article is capable of preventing the absorber from receiving an unnecessary force caused by the contractive forces of the elastic members and degrading in its absorptive function.

Further, the elastic members are attached continuously from along the left and right leg-side edges of the outer cover to the crotch zone, and part of the elastic members positioned in the crotch zone is weakened along with the softening process performed on the crotch zone of the outer cover, which can simplify the manufacturing steps of the absorbent article.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a disposable absorbent article according to an embodiment of the present invention and a method of manufacturing the same will be described.

FIG. 1is a front view of a disposable absorbent article (hereinafter briefly referred to as an “absorbent article”) according to an embodiment of the present invention, andFIG. 2is a diagram in which the disposable absorbent article shown inFIG. 1is developed by breaking left and right side bonded parts. Throughout the present specification, the front, back, left and right are mentioned relative to a wearer. For example, the wearer's left hand side is called left, and the right hand side is called right. The longitudinal direction Y (cf.FIG. 2) of an absorbent article1corresponds to the top-to-bottom or front-to-rear direction of the absorbent article1, and the lateral direction X (cf.FIG. 2) of the absorbent article1corresponds to the side-to-side direction of the absorbent article1.

As shown inFIGS. 1 and 2, this absorbent article1includes an outer cover2provided on the exterior side of the absorbent article1and an absorbent member3bonded to the skin facing side of the outer cover2.

The outer cover2has a front waist region6, a rear waist region7and a crotch region8to be applied to the wearer's front waist region, rear waist region and crotch region, respectively. Herein, the outer cover2is of a single-piece design integrally formed of the front waist region6, crotch region8and rear waist region7, by way of example, but may be formed of the front portion and rear portion separated at the crotch region.

Left and right edges6aof the front waist region6and left and right edges7aof the rear waist region7of the outer cover2are bonded by predetermined adhesion means while facing each other, so that left and right side bonded parts9are formed. Accordingly, the absorbent article1is in the pant-type structure having a waist opening11, and left and right leg openings12L and12R. The bonding at these side bonded parts9is achieved by adhesion means of one of ultrasonic welding, heating welding, an adhesive (e.g., a hot melt adhesive) and the like, or by combining some of them.

The absorbent member3is bonded by adhesion means such as an adhesive (e.g., a hot melt adhesive) to an area of the outer cover2on the skin facing side that substantially corresponds to the crotch region8.

A waist elastic member16is attached in a stretched state to the upper edge of the front waist region6of the outer cover2to extend along the upper edge. A waist elastic member17is attached in a stretched state to the upper edge of the rear waist region7to extend along the upper edge. Leg elastic members18and19are attached in a stretched state to left and right leg-side edges2aof the crotch region8forming the leg openings12L and12R to extend along these edges. A body elastic member20is attached in a stretched state in the lateral direction X to an area of the front waist region6around the wearer's torso (an intermediate part of the front waist region6in the longitudinal direction Y). A body elastic member21is attached in a stretched state in the lateral direction X to an area of the rear waist region7around the wearer's torso (an intermediate part of the rear waist region7in the longitudinal direction Y).

The outer cover2is formed by sandwiching the elastic members16to21between two sheet members26and27(cf.FIG. 5B) made of nonwoven fabric. The bonding of the sheet members26and27to each other and bonding of the elastic members16to21to the sheet members26and27are achieved by using adhesion means such as an adhesive (e.g., hot melt adhesive), heating welding, ultrasonic welding or the like.

The absorbent member3is formed of an absorbent body32including an absorber31for absorbing bodily exudates of a wearer, and left and right flaps33provided on the absorbent body32. The absorbent body32is formed by sandwiching the absorber31between a water repellent or liquid impermeable backsheet and a liquid permeable top sheet not shown. Flap elastic members34are attached in a stretched state to free ends of the flaps33, and the contractive force of the elastic members34raises the flaps33so that the flaps33fit the wearer's skin.

In the absorbent article1according to the present embodiment, a crotch zone8ain the crotch region8of the outer cover2to be applied to the wearer's crotch is subjected to a softening process. This improves the flexibility of the crotch zone8aof the outer cover2, which prevents the crotch zone8afrom being less likely to fit the wearer's body and causing rough and uncomfortable feeling to the wearer's skin.

More specifically, the softening process creates a plurality of almost slit-like holes41in the crotch zone8aof the outer cover2which extend through the sheet members26and27constituting the outer cover2, thereby making the material flexible. This effectively ensures the flexibility and achieves a high degree of breathability, thereby avoiding dampness. The holes41may be arranged in any pattern, and are herein arranged in a staggered pattern to be displaced from each other between adjacent rows of holes41.

In this absorbent article1, the leg elastic members18and19are attached continuously from along the left and right leg-side edges2aof the outer cover2to the crotch zone8a, and part of the leg elastic members18and19positioned in the crotch zone8ais cut short to be weakened. Part of the leg elastic members18and19positioned in the crotch zone8ais weakened in this manner, which prevents the absorber31from receiving an unnecessary force caused by the contractive forces of the leg elastic members18and19and degrading in its absorptive function. It should be noted that such structure also achieves advantages in manufacturing steps (which will be described later).

The method of manufacturing the absorbent article1will now be described with reference toFIGS. 3,4,5A and5B.

The method includes the following steps as shown inFIG. 3:

S6) side bonding step; and

The steps S1to S7are carried out substantially in the order listed above, however, the leg-hole forming step S4may be carried out prior to the absorbent-member attaching step S3. InFIG. 3, for ease of illustration, the leg elastic members18and19are each indicated simply by one dashed line, and other elastic members16,17,30and31are omitted from illustration.

As shown inFIG. 3, steps S1to S7are carried out while transporting an outer-cover continuous material42for forming the outer cover2and the like in a transport direction B1in the longitudinal direction of the outer-cover continuous material42. In step S1, the outer-cover continuous material42for forming the outer cover2is prepared. This outer-cover continuous material42is a series of material for forming the outer cover2extending continuously in the lateral direction X of the absorbent article1, and includes the elastic members16,17,30and31extending continuously and sandwiched between continuous materials for the sheet members26and27. At this time, the leg elastic members18and19, for example, are attached windingly along lines to be the leg-side edges2aand each portion to be crotch zone8aof the outer-cover continuous material42. Step S1corresponds to the step of attaching the elastic member according to the present invention.

In the next step S2, each portion to be the crotch zone8aof the outer-cover continuous material42is subjected to a softening process. The softening process is carried out by passing each portion to be the crotch zone8aof the outer-cover continuous material42between a blade roller46serving as a cutter and an anvil roller47, as shown inFIG. 4. The blade roller46is provided with a plurality of blades46aon its outer edge, and the blades46aare applied to the outer-cover continuous material42with the passage of the outer-cover continuous material42. As a result, as shown inFIGS. 5A and 5B, the plurality of slit-like holes41are created in each portion (region surrounded by two-dot chain line inFIG. 3) to be the crotch zone8aof the outer-cover continuous material42, so that the portion is softened.

With this softening process, the leg elastic members18and19attached to each portion to be the crotch zone8aof the outer-cover continuous material42are cut short by the blades46aof the blade roller46to be weakened. In this manner, attaching the leg elastic members18and19continuously to the outer-cover continuous material42and weakening part of the leg elastic members18and19positioned in each portion to be the crotch zone8awith the softening process can simplify the manufacturing steps of the absorbent article1.

Further, in the present embodiment, the blades46aof the blade roller46are arranged to perpendicularly cross the transport direction B1of the outer-cover continuous material42. Accordingly, the holes41created by these blades46aextend like slits in the direction perpendicular to the transport direction B1(vertical direction Y of the absorbent article1). Furthermore, the arrangement of the blades46aof the blade roller46in such direction allows the leg elastic members18and19attached substantially in the transport direction B1to be cut short appropriately and easily by the blades46a.

In the next step S3, each absorbent member3transported in a transport direction B2substantially in parallel to the transport direction B1of the outer-cover continuous material42is turned at 90 degrees as indicated by an arrow D1, and is attached to each portion to be the crotch zone8aof the outer-cover continuous material42.

In the next step S4, the leg holes48are formed in the outer-cover continuous material42in portions to be the leg-side edges2afor forming the leg openings12L and12R.

In the next step S5, the outer-cover continuous material42is folded such that its front portion and rear portion overlap each other. At this time, each absorbent member3is sandwiched therebetween.

In the next step S6, portions of the folded outer-cover continuous material42to be the side bonded parts9of each absorbent article1are bonded by the aforementioned adhesion means such as ultrasonic welding, so that the side bonded parts9are formed.

In the next step S7, each finished absorbent article1is cut into product and separated from each other.

In the above-described absorbent article1, the softening process is carried out only on the crotch zone8aof the outer cover2, however, portions other than the crotch zone8amay also be subjected to the softening process.

While the above-described absorbent article1is in the pant-type structure, the technique according to the present embodiment may also be applied to a hook-and-loop-type disposable diaper or a disposable absorbent article for combined use as pants and a diaper. Such disposable absorbent article for combined use as pants and a diaper represents an article having breaking parts for breaking the article into sections around the waist region and fastening members for re-fastening after breaking, which presents the pant-type structure when the breaking parts are not broken, and presents the hook-and-loop-type structure when the breaking parts are broken.