HK1038875B

HK1038875B - Disposable absorbent articles having passive side bonds and adjustable fastening systems

Info

Publication number: HK1038875B
Application number: HK02100709.0A
Authority: HK
Inventors: L‧L‧埃尔斯博格
Original assignee: 金伯利-克拉克环球有限公司
Priority date: 1998-06-19
Filing date: 1999-01-19
Publication date: 2005-04-29

Description

Disposable absorbent article with passive side bonding and adjustable fastening system

Technical Field

The present invention relates to disposable absorbent articles adapted to contain body exudates. More particularly, the present invention relates to a prefastened disposable absorbent article which has a passive side bond and an adjustable fastening system to maintain the article about the waist of the wearer.

Background

It is desirable for absorbent articles such as diapers, training pants, or incontinence garments to provide a tight, comfortable fit around the wearer and to contain body exudates. Moreover, it is desirable that such absorbent articles be removable from the wearer in a convenient and clean manner after soiling, without undesirably soiling the caregiver or surrounding area, such as the wearer's clothing. In some instances, it is desirable that such absorbent articles also be capable of being pulled up or down over the hips of the wearer to allow the wearer or caregiver to easily pull the article up and, if the article is not soiled, to easily remove the article. For example, such absorbent articles are useful for toilet training in children.

Conventional diapers are not provided in a pre-fastened condition and typically include a front waist region and a back waist region which are releasably attached about the hips of the wearer when in use by conventional fasteners such as adhesive tape fasteners or hook and loop type fasteners. For example, conventional fasteners typically include a pair of fasteners, such as adhesive tabs, located on the outermost corners of the diaper in the back waist portion of the diaper and a complementary fastener, such as a tape tab, located on the outer surface of the outer cover of the diaper in the front waist portion of the diaper. In this configuration, the diaper has been placed between the legs of the wearer and the adhesive tape tabs have been releasably attached to the tape tabs to secure the rear waist portion of the diaper to the front waist portion thereof to secure the diaper about the waist of the wearer. Such conventional diapers are easy to fasten around the wearer and remove from the wearer after use without undesirably soiling the caregiver. However, such conventional diapers are not pre-fastened prior to use and, as such, are not configured to be pulled up or down over the hips of the wearer when the fasteners are attached.

Several approaches have been taken to provide absorbent articles that effectively contain body exudates and are capable of being pulled up or down over the hips of the wearer. For example, some conventional absorbent articles, such as conventional training pants, include integral side panels that connect the front waist region to the back waist region of the absorbent article. The side panels can be stretchable so that the waist opening of the absorbent article can be expanded to allow the absorbent article to be pulled up or down over the hips of the wearer as desired. Such side panels have been designed to be torn to remove the pant from the wearer after it has been soiled.

However, many of these measures are not entirely satisfactory. For example, absorbent articles such as training pants are not always capable of a snug fit to the wearer, while not being sufficiently stretchable to be pulled up or down over the hips of the wearer. Often, such training pants fit loosely about the waist of the wearer, which can undesirably result in leakage. As a result, many such articles do not contain bodily exudates as effectively as conventional diaper-type articles that can be adjusted to achieve a more consistent fit with the wearer. Moreover, soiled absorbent articles with integral side panels, such as conventional training pants, are not always removed satisfactorily. For example, the side panels are difficult to tear when the article is intended to be removed from the waist of the wearer rather than pulled over the hips of the wearer.

Thus, regardless of the purpose for which the absorbent article is improved, there is always a need for absorbent articles that provide the advantages of conventional training pants and conventional diapers. That is, there remains a need for an absorbent article that conforms to the wearer to effectively contain bodily exudates, that can be pulled up and down over the hips and buttocks of the wearer without opening, and that is easily secured about and removed from the wearer in a convenient and clean manner. Furthermore, there is a need for a disposable absorbent article comprising a releasably prefastened waist portion which is capable of reliably being pulled up over the legs and hips of the wearer.

Summary of The Invention

In view of the difficulties and problems discussed above, a novel prefastened disposable absorbent article having a passive side bond and an adjustable fastening system has been found. In one aspect, the present invention is directed to a prefastened disposable absorbent article which defines an absorbent, a front waist region, a back waist region, a crotch region extending between and interconnecting the waist regions, and a pair of opposed side edges. The prefastened absorbent article includes a pair of primary fasteners which are located on opposite side edges in one of the waist regions. The primary fasteners overlap and releasably engage the opposing waist regions of the absorbent article to provide a prefastened absorbent article. The article also includes a pair of passive side bonds located inboard of the primary fasteners. The passive side bonds releasably connect the overlapped portion of one waist region to the opposing waist region to help maintain the prefastened absorbent article in a prefastened condition.

In another aspect, the present invention is directed to a prefastened disposable absorbent article which defines an absorbent, a front waist region, a back waist region, a crotch region which extends between and connects the waist regions and a pair of opposed ear regions which are located in one of the waist regions and overlap the opposed waist region. The absorbent article includes a pair of primary fasteners positioned on the opposing ears and releasably engageable with the opposing waist regions of the absorbent article to provide a prefastened absorbent article. The article further includes a belt segment defining opposite ends and positioned at the one waist portion, and a pair of secondary fasteners positioned at the opposite ends of the belt segment. The secondary fasteners are configured to releasably engage the opposing waist region after the prefastened absorbent article is pulled up over the hips of the wearer to conform the waist region to the body of the wearer. The article also includes a pair of passive side bonds positioned inboard of the primary fasteners on the opposing ears. The passive side bonds releasably attach the landing zone portion of the ear portion to the opposing waist region to help maintain the prefastened absorbent article in a prefastened condition.

In yet another aspect, the present invention is directed to a prefastened disposable absorbent article which defines a front waist region, a back waist region, a crotch region extending between and joining the waist regions, and a pair of opposed side edges. The absorbent article comprises an outer cover and an absorbent chassis. The absorbent chassis includes a back sheet joined to the outer cover, a body side liner joined in superposed relation to the back sheet, and an absorbent core disposed between the back sheet and the body side liner. The absorbent article includes a pair of primary fasteners positioned on the outer cover on laterally opposite side edges of the rear waist region of the absorbent article. The primary fasteners are configured to releasably engage an outer surface of the absorbent article in the front waist portion of the absorbent article. The article further includes a belt segment positioned at the rear waist portion of the absorbent article and defining a pair of opposed ends, and a pair of secondary fasteners positioned at the opposed ends of the belt segment. The secondary fasteners are configured to releasably engage the outer surface of the front waist region after the prefastened absorbent article is pulled up over the hips of the wearer to further conform the waist region to the body of the wearer. The article further includes a pair of passive side bonds positioned inboard of the primary fasteners on the back waist region. The passive side bonds releasably connect the overlapped portion of the back waist region to the front waist region to help maintain the prefastened absorbent article in a prefastened condition.

In another aspect, the present invention is directed to a prefastened disposable absorbent article which defines an absorbent, a front waist region, a back waist region, a crotch region extending between and interconnecting the waist regions, and a pair of opposed side margins. The absorbent article includes a pair of primary fasteners positioned on opposite side edges in one of the waist regions. The primary fasteners are releasably engageable with opposing waist regions of the disposable absorbent article to define a waist circumference dimension. The absorbent article further includes a waist size adjustment device that reduces the waist circumference of the absorbent article without loosening the primary fasteners to conform the waist to the body of the wearer after the pre-fastened absorbent article has been pulled up. The article further includes a pair of passive side bonds positioned inboard of the primary fasteners on one waist region and releasably attaching the overlapped portion of the one waist region to the opposing waist region to assist in maintaining the pre-fastened absorbent article in a pre-fastened condition.

The present invention advantageously provides a prefastened disposable absorbent article which includes a passive side bond and an adjustable fastening system engagement which includes an adjustable fastening system engagement to improve fit and performance. The absorbent article of the present invention can be pulled up or down reliably over the hips of the wearer to facilitate toilet training of the wearer as in conventional training pants. Moreover, similar to conventional diapers, the absorbent articles of the present invention are advantageously intended for use by wearers and are relatively easy and clean to remove from the wearer after soiling.

The present invention and its advantages are more fully understood by reference to the following detailed description of the invention, taken together with the accompanying drawings, in which like reference numerals refer to like elements. The drawings are exemplary only, and are not limiting upon the scope of the appended claims.

FIG. 1 representatively shows a side view of one example of a prefastened disposable absorbent article in accordance with the present invention;

FIG. 2 representatively shows a side view of the disposable absorbent article of FIG. 1 in which the secondary fasteners have been extended and engaged to conform the waist of the article to the waist of the wearer after the article has been pulled up over the hips of the wearer;

FIG. 3 representatively shows a plan view of the disposable absorbent article of FIG. 1 in an unfastened, stretched and laid flat condition with the article surface contacting the wearer facing the viewer; and

fig. 4 typically shows a plan view of the disposable absorbent article of fig. 1 in an unfastened, stretched and laid flat condition, with the article surface contacting the clothing of the wearer facing the viewer.

The present invention relates to prefastened disposable absorbent articles which are shaped to fit closely to the body of the wearer so as to contain bodily exudates effectively while being capable of being pulled up and down over the hips and buttocks of the wearer. The prefastened disposable absorbent article can also be easily secured to the waist of the wearer and can be removed directly from the waist of the wearer. Thus, the absorbent article of the present invention functions like a conventional training pant while maintaining a pre-fastened configuration, or is not fastened prior to or during use, and thus functions like a conventional diaper.

The prefastened disposable absorbent article is adapted to be worn adjacent the body of the wearer to absorb and contain the various exudates discharged from the body. As used herein, the term "disposable" refers to articles that are intended to be discarded after a limited use and are not intended to be laundered or otherwise restored for reuse. The prefastened disposable absorbent article of the present invention will be described in terms of a prefastened disposable diaper article adapted to be worn by an infant about its lower torso. It will be appreciated that the disposable absorbent articles of the present invention are equally suitable for use as other types of absorbent articles, such as adult incontinence articles, training pants, feminine hygiene products, other personal care or health care garments, and the like.

Figures 1 and 2 typically illustrate one example of a prefastened disposable diaper in accordance with the invention, the prefastened disposable diaper being generally designated by the numeral 20. Fig. 3 and 4 typically illustrate the prefastened diaper of fig. 1 in an unfastened, stretched and laid out condition. As shown in figures 1-4, the diaper 20 defines a front waist region 22, a back waist region 24, a crotch region 26 extending between and interconnecting the front and back waist regions 22, 24, and a pair of laterally opposing ear portions 28, the ear portions 28 being integral with or interconnected to the back waist region 24. The diaper 20 further defines a pair of laterally opposing side edges 30, a pair of longitudinally opposing waist edges 32, an interior surface 34 configured for wearer contact, an exterior surface 36 opposite the interior surface 34, a longitudinal direction 38, and a lateral direction 40.

The front waist portion 22 comprises the portion of the diaper 20 which is disposed in the front of the wearer when worn, and the back waist portion 24 comprises the portion of the diaper 20 which is disposed in the back of the wearer when worn. The crotch portion 26 of the diaper 20 comprises the portion of the diaper 20 which, when worn, is disposed between the legs of the wearer and covers the lower torso of the wearer. The ears 28 comprise those portions of the diaper which, when worn, are disposed over the wearer's lateral hip region. The laterally opposing side edges 30 of the diaper 20 generally define leg openings that may be curvilinear. The waist edge 32 of the diaper 20 is shaped to encircle the waist of the wearer when worn and provides a waist opening when fastened, thereby defining a waist circumference dimension.

The illustrated diaper 20 includes an outer cover 42, an absorbent chassis 44, and a multi-functional fastening system 60. The fastening system 60 may include a pair of primary fasteners 62, a pair of secondary fasteners 64, and a pair of laterally opposite passive side bonds 80 and 82. The absorbent chassis 44 is shaped to contain and/or absorb any bodily exudates discharged from the wearer. While the outer cover 42, the multi-functional fastening system 60 is shaped to maintain the diaper 20 around the waist of the wearer, to hide the absorbent chassis 44 from view, and to provide a garment-like appearance. The diaper 20 may also include leg elastics 52, retention folds 54 and waist elastics 56 as are known to those of ordinary skill in the art. It should be recognized that the individual components of the diaper 20 may be selected based upon the intended use of the diaper 20.

The outer cover 42 of the diaper 20 may suitably be made of a liquid permeable or liquid impermeable material. Since the absorbent chassis 44 of the various aspects of the present invention is designed to contain the exudates discharged from the wearer, in general, the outer cover 42 need not be liquid impermeable. For example, the outer cover 42 may comprise different woven or nonwoven materials, such as spunbond, meltblown, cotton, rayon, or combinations thereof, such as spunbond-meltblown-spunbond (SMS) laminates.

Additionally, the outer layer 42 may be at least partially liquid impermeable to further prevent any leakage of body exudates. For example, a typical outer cover 42 may be made of a thin plastic film or other flexible liquid impermeable material. In a particular aspect, the outer cover 42 may be made from a polyethylene film having a thickness of from about 0.012 millimeters (0.5 mils) to about 0.051 millimeters (2.0 mils). The outer cover 42 may also be formed from a woven or nonwoven fibrous web layer that has been constructed or treated, in whole or in part, to impart a desired level of liquid impermeability to selected regions. Moreover, the outer cover 42 may optionally be constructed of a microporous "breathable" material that permits vapors to escape from the diaper 20 while woven liquid exudates pass through the outer cover 42. Also, the outer cover layer 42 may be an elastic material, such as a stretch-heat laminate (STL), neck-bond laminate (NBL), or stretch-bond laminate (SBL) material. Methods for making such materials are well known to those of ordinary skill in the art and are described in Misneski et al, U.S. Pat. No. 4,663,220 published 5.5.1987, U.S. Pat. No. 5,226,992 published 7.13.1993, Mormen et al, and European patent application EP 0217032 published 4.8.1987, Taylor et al. The disclosure of which is hereby incorporated by reference.

If it is desired that the outer cover 42 exhibit a more cloth-like feel, the outer cover 42 may comprise a polyethylene film having a nonwoven fabric, such as a spunbond fabric of polyolefin fibers, laminated to its outer surface. For example, a polyethylene film having a thickness of about 0.015 millimeters (0.6 mils) may have a spunbond web of polyolefin fibers thermally laminated thereto, the polyolefin fibers having a thickness of about 1.5 to 2.5 denier per filament, the nonwoven web having a basis weight of about 24 grams per square meter (0.7 ounces per square yard). Additionally, the outer cover layer 42 may be a stretch-heat laminate (STL) material comprising a film layer disposed between two spunbond layers and having a basis weight of about 70-75 grams per square meter. The film layer may be made of meltblown polypropylene fibers and the spunbond layer may be made of polypropylene fibers. The outer cover 42 may also include bicomponent fibers, such as polyethylene/polypropylene bicomponent fibers. Methods of forming such cloth-like outer covers are well known to those of ordinary skill in the art.

The absorbent chassis 44 of the diaper 20 is suitably joined with the outer cover 42 to provide a disposable diaper 20. The absorbent chassis 44 may be joined to the outer cover 42 in a manner well known to those skilled in the art. For example, the absorbent chassis 44 may be bonded to the outer cover 42 using adhesive bonding, thermal bonding, or ultrasonic bonding techniques known to those skilled in the art. Alternatively, the absorbent chassis 44 can be attached to the outer cover 42 using conventional fasteners, such as buttons, hook and loop fasteners, adhesive tape fasteners, and the like. Other components of the diaper 20 may be suitably joined together using similar methods.

Preferably, the absorbent chassis 44 is joined to the outer cover 42 only at or near the waist edge 32 of the outer cover 42 to form front fastened portions, back fastened portions and unattached portions extending between and joining the fastened portions. The unattached portions of the absorbent chassis 44 remain substantially unattached to the outer cover 42 and are generally shaped to fit between the legs of the wearer and to at least partially cover the lower torso of the wearer during use. As a result, the unattached portions are typically the portions of the absorbent chassis 44 that are shaped to initially contain the body exudates of the wearer. In this way, the absorbent chassis 44 is attached to the outer cover 42 in a manner that secures the frame 44 in place during use without otherwise restricting movement of the outer cover 42. Alternatively, the absorbent chassis 44 may be secured to the outer cover layer 42 along its entire longitudinal length or any portion thereof or only along the periphery of the absorbent chassis 44.

As representatively illustrated in FIG. 3, the absorbent chassis 44 of the present invention can include a back sheet 46, a body side liner 48 attached in a superposed relationship to the back sheet 46, and an absorbent core 50 positioned between the body side liner 48 and the back sheet 46. In an alternative configuration, the outer cover 42 is at least partially resistant to the flow of liquid therethrough, and the backsheet 46 may optionally be omitted from the absorbent chassis 44.

The absorbent chassis 44 is generally conformable and can absorb and retain bodily exudates. The absorbent chassis 44 can have many shapes and sizes. For example, as representatively illustrated in FIG. 3, the absorbent chassis 44 can be rectangular, I-shaped, or T-shaped. The size and absorbent capacity of the absorbent chassis 44 should be compatible with the size of the intended wearer and the fluid loading imparted by the intended use of the diaper 20. Generally, it is desirable that the absorbent chassis 44 have an absorbent capacity of at least about 300 grams of urine. Generally, it is preferred that the absorbent chassis 44 be narrower in the crotch region 26 than in the waist regions 22 and 24. The absorbent chassis 44 of the present invention has been found to be particularly useful when the crotch portion 26 has a width dimension of from about 2.5 to about 10.2 centimeters (1.0 inch to 4.0 inches), preferably no more than about 7.6 centimeters (3.0 inches), and more preferably no more than about 5.1 centimeters (2.0 inches). The narrow crotch width dimension of the absorbent chassis 44 allows the absorbent chassis 44 to better fit between the legs of the wearer.

As representatively illustrated in FIG. 3, the bodyside liner 48 of the absorbent chassis 44 suitably has a body-facing surface that is intended to be worn adjacent to the body of the wearer, is compliant, soft, and non-irritating to the wearer's skin. Further, the bodyside liner 48 may be less hydrophilic than the absorbent core 50, so as to present a relatively dry surface to the wearer, and sufficiently porous to be liquid permeable, allowing liquid to readily penetrate through its thickness. The bodyside liner 48 may be manufactured from a wide selection of web materials, such as porous foams, reticulated foams, apertured plastic films, natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polyester or polypropylene fibers), or a combination of natural and synthetic fibers. A bodyside liner 48 is suitably employed to help isolate the wearer's skin from liquids remaining in the absorbent core 50 of the absorbent chassis 44.

Different woven and nonwoven fabrics can be used for the bodyside liner 48. For example, the bodyside liner can be composed of a meltblown or spunbond web of polyolefin fibers. The bodyside liner can also be a bonded carded web made from natural and/or synthetic fibers. The bodyside liner can be made from a substantially hydrophobic material, which can optionally be treated with a surfactant, or otherwise treated to impart a desired level of wettability and hydrophilicity. In a particular embodiment of the present invention, the bodyside liner 48 comprises a nonwoven, spunbond polypropylene fabric composed of fibers of about 2.8 to 3.2 denier formed into a web having a basis weight of about 22 grams per square meter and a density of about 0.06 grams per cubic centimeter. The fabric may be surface treated with about 0.28 weight percent of a surfactant commercially available under the trade name Triton X-102 from Rohm and Haas company.

As representatively illustrated in FIG. 3, the backsheet 46 of the absorbent chassis 44 may suitably be formed of a material which is either liquid permeable or liquid impermeable. It is generally preferred that the backsheet 46 be made of a substantially liquid impermeable material. A typical backsheet may be made of a thin plastic film or other flexible liquid impermeable material. For example, the backsheet 46 may be made from a polyolefin film having a thickness of from about 0.012 millimeters (0.5 mils) to about 0.051 millimeters (2.0 mils). The backsheet 46 may also include a film layer having a nonwoven fabric, such as a spunbond fabric of polyolefin fibers, laminated to the outer surface thereof. The backsheet 46 may also be formed of a material similar to that described above as being suitable for the outer cover 42. Further, the backsheet 46 may be composed of a woven or nonwoven fibrous web layer that is constructed or treated, in whole or in part, to impart a desired level of liquid impermeability to selected regions that are adjacent or proximate the absorbent core 50. Further, the backsheet 46 may optionally be formed of a microporous "breathable" material that permits vapors to escape from the absorbent core 50 while still preventing liquid exudates from passing through the backsheet 46. For example, the back sheet 46 may comprise a breathable polyethylene film material commercially available under the trade name EKXAIRE from Exxon chemical Patents, Inc., of Linden, N.J.. In such a configuration, it is preferred that the outer cover 42 also include such breathable material.

The body side liner 48 and the backsheet 46 are generally adhered to one another to form a pocket in which the absorbent core 50 is positioned to provide the absorbent chassis 44. The bodyside liner 48 and the backsheet 46 can be directly adhered to each other around the outer periphery of the absorbent chassis 44 by any means known to those skilled in the art, such as adhesive bonding, sonic bonding, or thermal bonding. For example, the body side liner 48 can be secured to the backsheet 46 using a uniform continuous layer of adhesive, a patterned layer of adhesive, a sprayed or meltblown pattern of adhesive, or a line, swirl, or dots of adhesive. It should be noted that the bodyside liner 48 and the backsheet 46 need not both extend completely to the outer periphery of the absorbent chassis 44. For example, the backsheet 46 may extend to the outer periphery of the absorbent chassis 44, and the backsheet 48 may be joined with the backsheet 46 inside the outer periphery of the absorbent chassis 44, or further toward the longitudinal centerline of the diaper 20. In another construction, particularly where the backsheet 46 is removed, the bodyside liner 48 may be suitably bonded directly to the absorbent core 50 or to the outer cover 42.

As representatively illustrated in FIG. 3, the absorbent core 50 is positioned between the bodyside liner 48 and the backsheet 46 to form the absorbent chassis 44. The absorbent core 50 is desirably conformable and capable of absorbing and retaining bodily exudates. The absorbent core 50 may have any of a number of shapes and sizes. For example, the absorbent core may be rectangular, I-shaped, or T-shaped. It is generally preferred that the absorbent core 50 be narrower in the crotch region 26. The size of the absorbent core 50 should be compatible with the size of the intended wearer and the desired absorbent capacity of the absorbent chassis 44.

The absorbent core 50 of the absorbent chassis 44 may suitably comprise various types of wettable, hydrophilic fibrous materials. Examples of suitable materials include naturally occurring organic fibers composed of inherently wettable materials, such as cellulose fibers; synthetic fibers composed of cellulose or cellulose derivatives, such as rayon fibers; inorganic fibers composed of inherently wettable materials, such as glass fibers; synthetic fibers composed of inherently wettable thermoplastic polymers, such as specialty polyester and polyamide fibers; and synthetic fibers composed of non-wettable thermoplastic polymers such as polypropylene fibers, which can be hydrophilized using techniques well known to those of ordinary skill in the art. The absorbent core 50 may also comprise a selected mixture of the various fibers described above.

In a particular aspect of the invention, the absorbent core 50 may comprise a matrix of hydrophilic fibers, such as a web of cellulosic fibers, mixed with particles of a high absorbency material such as the well known superabsorbent materials. As used herein, the term "high absorbency material" refers to materials that are capable of absorbing at least 10 times their own weight in liquid. In a particular embodiment, the absorbent core 50 comprises a mixture of superabsorbent hydrogel-forming particles and wood pulp fluff. The wood pulp fluff may be exchanged with synthetic, polymeric, meltblown fibers, or with a mixture of meltblown fibers and natural fibers. The high absorbency material may be substantially homogeneously mixed or heterogeneously mixed with the hydrophilic fibers. The high absorbency material may also be disposed within a generally separate layer within the hydrophilic fiber matrix. Alternatively, the absorbent core 50 may comprise a laminate of fibrous webs and high absorbency material, or other suitable configuration that maintains the high absorbency material in localized areas.

The superabsorbent materials may be selected from natural, synthetic and modified natural polymers and materials. The superabsorbent materials can be inorganic materials, such as silica gels, or organic compounds such as crosslinked polymers. The term "crosslinked" refers to any means for rendering normally water-soluble materials effectively substantially water-insoluble but swellable. Such methods may include, for example, physical entanglement, crystalline groups, covalent bonds, ionic complexes and associations, hydrophilic associations, such as hydrogen bonding, and hydrophobic associations or van der waals forces.

Examples of synthetic, polymeric, superabsorbent materials include poly (acrylic acid) and poly (methacrylic acid), poly (acrylamide), poly (vinyl ether), maleic anhydride copolymers with vinyl ether and alpha olefin, poly (vinyl pyrrolidone), poly (vinyl morpholine), basic metal and ammonium salts of poly (vinyl alcohol), and mixtures and copolymers thereof. Moreover, polymers suitable for use in the absorbent core include natural and modified natural polymers, such as hydrolyzed acrylonitrile-grafted starch, acrylic acid grafted starch, methyl cellulose, chitosan, carboxymethyl cellulose, hydroxypropyl cellulose, and natural gums, such as alginates, synthetic biopolymer gums, locust bean gum, and the like. Mixtures of natural and wholly or partially synthetic absorbent polymers are also useful for the present invention.

The high absorbency material may be in any of a number of geometric forms. As a general rule, it is desirable for the superabsorbent material to be in the form of discrete particles. However, the high-absorbency material may also be in the form of fibers, flakes, rods, balls, needles, or the like. Aggregates of particles of superabsorbent material may also be used. An example of a superabsorbent polymer suitable for use in the present invention is the superabsorbent polymer designated IM5000, which is commercially available from Hoechst-Celanese, an enterprise having offices in Portsmouth, Virginia. Other suitable superabsorbent materials can include superabsorbent polymers commercially available from Dow Chemical corp, an enterprise having offices in Midland, Michigan.

As a general rule, superabsorbent materials are employed in the absorbent core 50 of the present invention in amounts of from about 5% to about 95%, preferably from about 10% to about 60%, by weight, based on the total weight of the absorbent core 50. The distribution of the superabsorbent material in different portions of the absorbent core 50 may vary depending on the end use of the absorbent core 50.

As representatively illustrated in FIG. 3, the absorbent chassis 44 of the disposable diaper 20 may include a pair of retention flaps 54, the flaps 54 being configured to provide a side stream barrier to bodily exudates. The retention folds 54 may be located along laterally opposite side edges of the absorbent chassis 44. Each retention fold 54 typically defines an unsecured edge configured to maintain an upright, vertical configuration in at least the crotch portion 26 of the diaper 20 to form a seal with the wearer's body. The retention fold 54 may extend longitudinally along the entire length of the absorbent chassis 44 or may extend only partially along the length of the absorbent chassis 44. When the retention fold 54 is shorter in length than the absorbent chassis 44, the retention fold 54 may optionally be located anywhere along the side edges of the absorbent chassis 44. In a particular aspect of the invention, the retention fold 54 extends along the entire length of the absorbent chassis 44 to better contain body exudates.

Such retention features 54 are generally known to those of ordinary skill in the art. Suitable constructions and arrangements of retention tabs 54 are described, for example, in U.S. patent No. 4,704,116 issued to k.eloe, 11/3 1987, which is hereby incorporated by reference.

The disposable diaper 20 of the various aspects of the present invention further comprises elastic members at the waist edge 32 and the side edges 30 of the diaper 20 to further prevent leakage of body exudates and to support the absorbent chassis 44. For example, as representatively illustrated in FIG. 3, the diaper 20 of the present invention may include a pair of leg elastics 52, the leg elastics 52 being joined to the laterally opposing side edges 30 in the crotch portion 26 of the diaper 20 and a pair of waist elastics 56, the waist elastics 56 being joined to the longitudinally opposing waist edges 32 of the diaper 20. The leg elastic members 52 and waist elastic members 56 are generally adapted to fit around the legs and waist of the wearer during use in order to maintain a frontal, contacting relationship with the wearer and thereby effectively reduce or eliminate leakage of body exudates from the diaper 20.

Suitable materials for the leg elastic members 52 and the waist elastic member 56 are well known to those skilled in the art. Examples of such materials are sheets or threads or tapes of polymeric, elastic material which are either adhered to the edges 30 and 32 of the diaper 20 in a stretched position or which are attached to the edges 30 and 32 of the diaper 20 when the edges are gathered in order to exert an elastic restraining force on the edges 30 and 32 of the diaper 20. The leg elastics may also comprise materials such as polyurethane, synthetic and natural rubber. In a particular aspect of the invention, the elastic member may be formed from a single strand of 620 decitex LYCRA, which is commercially available from e.i. dupont de Nemours co. When a single strand of elastic is used, the waist and leg elastics may comprise any suitable number of elastic strands to provide a seal for body exudates. For example, the leg elastic 52 may comprise from about 1 to about 10 elastic strands. The leg elastic members 52 and 56 may be stretched prior to attachment to the diaper 20. For example, the elastic members 52 and 56 may be extended at least about 150%, and preferably from about 200% to about 500%, prior to attachment, so that when relaxed, the elastic members gather the edges 30 and 32 of the diaper 20. The elastic members 52 and 56 can be joined to the diaper 20 by any method known to those skilled in the art. For example, adhesives, thermal or ultrasonic bonding techniques, or a combination thereof may be used to attach the elastic members to the edges of the diaper 20. One suitable adhesive includes Findley H-2096 hot melt adhesive, which is commercially available from Findley Adhesives, Inc.

The absorbent articles of the various aspects of the present invention further comprise a multi-functional fastening system 60 for securing the absorbent article about the waist of the wearer. The multi-functional fastening system 60 comprises a fastener located on one of the waist regions 22 and 24 of the diaper 20 that is configured to releasably adhere to the opposing waist region of the diaper 20 in order to maintain the diaper about the waist of the wearer. The use of refastenable or releasably adhered fasteners allows the diaper 20 to be easily secured to or removed from the waist of a wearer.

One suitable multi-functional fastening system is described in U.S. patent application No. 08/907585, (international publication No. W099/07319), entitled "multi-functional fastener for disposable absorbent articles", filed 8/1997, to j.d. suprise, the disclosure of which is hereby incorporated by reference. As representatively illustrated in FIGS. 1-4 of the present invention, the multifunctional fastening system 60 can include a pair of primary fasteners 62, with the primary fasteners 62 being located on the side edges 30 of the diaper 20 in the back waist region 24 of the diaper 20. In this configuration, the primary fasteners 62 are configured to encircle the hips of the wearer and engage the outer surface 36 of the front waist region 22 of the diaper 20 to maintain the diaper 20 on the wearer. Alternatively, the primary fasteners 62 may be located at the front waist region 22 and may be shaped to releasably engage the outer surface 36 of the back waist region 24 of the diaper 20.

Preferably, the primary fasteners 62 are releasably engageable directly with the outer surface of the outer cover 42 of the diaper 20 for improved fastening ease. Alternatively, as representatively illustrated in fig. 4, the disposable diaper 20 of the present invention further includes an attachment panel 66, the attachment panel 66 being positioned on the outer cover 42 in one of the waist regions 22 and 24 of the diaper 20. In this configuration, the primary fasteners 62 releasably engage the attachment tabs 66 to hold the diaper 20 about the waist of the wearer. When the primary fasteners 62 are releasably engaged, the side edges 30 of the diaper 20 define leg openings that are shaped to encircle the waist of the wearer and the waist edges 32 define a waist opening that is shaped to encircle the waist of the wearer. As shown in figure 4, the connecting panel 66 may comprise two separate panels that are positioned along opposite side edges in one of the waist regions 22 and 24 of the diaper 20. Alternatively, the connecting tab 66 may comprise a single piece of material that extends substantially across the respective waist region of the diaper 20.

In various aspects of the invention, the primary fasteners 62 are releasably engaged with the outer surface of the opposed waist regions 22 and 24 of the diaper 20 before the diaper 20 is worn on the wearer to provide a prefastened diaper. In this configuration, the prefastened diaper 20 can be pulled up or down over the legs and hips of the wearer. If the diaper 20 should become soiled during use, the primary fasteners 62 can be unfastened to allow the diaper 20 to be easily removed from the waist of the wearer with a reduced risk of inadvertently soiling the wearer's clothing or legs. Thus, in this configuration, the diaper 20 of the various aspects of the present invention can be pulled up or down over the hips of the wearer, such as conventional training pants, and easily removed by unfastening fasteners similar to conventional diaper products.

The multi-functional fastening system 60 on a disposable diaper 20 of the present invention may also include at least one secondary fastener so that the securement of the diaper 20 about the waist of the wearer is improved when the primary fastener 62 is releasably engaged. Such secondary fasteners can be configured to conform the waist regions 22 and 24 of the diaper 20 to the waist of the wearer. Alternatively, in embodiments where the secondary fasteners are omitted, the primary fasteners 62 can be re-engaged after the diaper is donned to further conform the waist of the diaper to the waist of the wearer.

The diaper 20 of the embodiment includes a pair of secondary fasteners 64, the secondary fasteners 64 being located on the side edges 30 in one of the waist regions 22 and 24 of the diaper 20. The secondary fasteners 64 are configured to encircle the hips of the wearer and engage the outer surface 36 in the opposing waist regions 22 and 24 of the diaper 20. The secondary fasteners 64 may be located on the side edges 30 of the diaper 20 in the back waist region 24 of the diaper 20. In this configuration, the secondary fasteners 64 are also configured to encircle the hips of the wearer and engage the outer surface 36 of the front waist region 22 of the diaper 20 to hold the diaper 20 on the wearer. Alternatively, the secondary fasteners 64 may be located at the front waist region 22 and may be configured to releasably engage the outer surface 36 of the back waist region 24 of the diaper 20.

Preferably, the secondary fasteners 64 are releasably engageable directly with the outer surface of the outer cover 42 of the diaper 20 to improve fit and facilitate fastening.

Alternatively, as described above with reference typically to figures 1-4, the diaper 20 of the present invention further includes an attachment panel 66, the attachment panel 66 being positioned on the outer cover 42 in one of the waist regions 22 and 24 of the diaper 20. In this configuration, the secondary fasteners 64 can also be releasably engaged with the attachment tabs 66 to retain the diaper 20 about the waist of the wearer.

It has been found that the use of such secondary fasteners is particularly desirable when the primary fasteners 62 are releasably engageable with the respective waist region of the diaper 20 prior to use to provide a prefastened diaper which can be pulled up over the legs and hips of the wearer. In this configuration, the waist opening of the diaper 20 must be sufficient to allow the prefastened diaper 20 to be pulled over the hips of the wearer when the primary fasteners 62 are engaged. However, the waist circumference of the wearer's waist is typically less than the hip circumference around the wearer's hips. In this way, the waist opening of the pre-fastened diaper 20 may not coincide with the waist of the wearer, which may disadvantageously result in leakage. In this configuration, the secondary fasteners of the diaper 20 are configured to conform the waist of the diaper 20 to the wearer by reducing the waist circumference of the diaper 20 after the prefastened diaper is placed on the wearer. In this way, the caregiver does not need to reposition the primary fasteners 62 to conform the waist regions 22 and 24 to the waist of the wearer. As a result, when the diaper 20 is removed from the wearer, the caregiver can simply detach the secondary fasteners 64 and remove the prefastened diaper from the hips and legs of the wearer, if desired, without having to reposition the primary fasteners 62. Alternatively, the caregiver can detach the primary and secondary fasteners 62 and 64 to remove the diaper in a manner similar to a conventional diaper.

In this configuration, the secondary fasteners 64 serve to maintain the diaper 20 in a snug, consistent fit about the waist of the wearer to reduce leakage of body exudates during use. The primary fasteners 62 are used to maintain the front and back waist regions 22 and 24 of the diaper 20 joined in such a manner that the diaper 20 can be pulled up or down over the hips of the wearer after the secondary fasteners 64 have been unattached. The secondary fasteners 64 may also be selectively unfastened to permit viewing of the diaper 20 to determine if the diaper has been soiled. The primary fasteners 62 can also provide a "child-resistant" function by maintaining the diaper 20 at least partially secured about the waist of the wearer if the wearer disengages the secondary fasteners 64.

The secondary fasteners 64 may also provide improved fit when the diaper 20 exhibits an unfastened appearance similar to a conventional diaper. For example, when initially tightening around a wearer, the primary fasteners 62 may be difficult to accurately locate due to the wearer's motion. Thus, in this case, the secondary fasteners can be used to provide a better consistent fit after the primary fasteners 62 have been engaged.

Suitable fasteners known to those of ordinary skill in the art may include adhesive tape, tab fasteners, adhesives, hook and loop fasteners, mushroom fasteners, snaps, pins, bands, and the like, as well as combinations thereof. For example, as representatively shown in fig. 3, the primary and secondary fasteners 62, 64 can be hook-type fasteners and the outer cover 42 or the attachment panel 66 can be configured to function as complementary loop-type fasteners. Preferably, the fasteners 62 and 64 are hook-type fasteners releasably engageable directly with the outer cover 42. This configuration enables very little incremental change in the size of the waist opening over a wide range to fit the waist of the wearer. The fasteners can be of any shape and size that provides the desired fastening of the diaper 20 about the waist of the wearer. It is also desirable that the outer surface of the secondary fastener 64 provide a visual cue to the caregiver as to its location. For example, in one embodiment, the secondary fasteners 64 are a different color than the exterior surface of the diaper 20, thereby allowing the caregiver to easily locate the secondary fasteners 64.

In the illustrated embodiment, the primary fasteners 62 are attached directly to the side edges 30 of the diaper 20 in one of the waist regions 22 and 24. The primary fasteners 62 may be bonded to the side edges 30 by any known means, such as adhesive bonding, sonic bonding, or thermal bonding as known to those of ordinary skill in the art.

The secondary fasteners 64 may be suitably secured to the diaper 20 in any manner that provides the desired improved securement and conformity of the waist regions 22 and 24 of the diaper 20 about the waist of the wearer after the diaper 20 has been pulled up over the hips of the wearer. For example, as representatively illustrated in fig. 3 and 4, the diaper 20 of the various aspects of the present invention may further include a belt segment 68, the belt segment 68 being located at one of the waist regions 22 and 24 of the diaper 20. The illustrated belt segments 68 define a pair of laterally opposite end portions 70 and fixed portions 72 that are secured to the respective waist regions 22 and 24 of the diaper 20. The secondary fastener 64 is connected to an end 70 of the belt segment 68. In this configuration, the end portions 70 of the belt segments 68 are shaped to encircle the hips of the wearer such that the secondary fasteners 64 releasably engage the opposing waist regions to provide improved fit of the diaper 20 on the wearer after the diaper 20 has been pulled up over the legs and hips of the wearer. To provide an improved fit about the waist of the wearer without affecting the appearance of the outer cover 42 of the diaper 20, a substantial portion of the length of the belt segments 68 is preferably disposed along the interior surface 34 of the diaper 20 in the respective waist regions 22 and 24. In the configuration typically shown in fig. 3, the diaper 20 also includes a pair of slots 74 along which the ends 70 of the belt segments 68 slidably extend. In this manner, the end portions 70 of the belt segments 68 and the secondary fasteners 64 are positioned on the outer surface 36 of the diaper with the remainder of the belt segments 68 extending transversely along the inner surface 34 of the diaper 20 between the diaper and the wearer. As shown, the secondary fasteners 64 are preferably configured to releasably engage the outer surface 36 of the diaper 20 adjacent the slot 74 for improved control and easier fastening.

The slot 74 may be provided by any means known to those of ordinary skill in the art. For example, the slot 74 may be provided by cutting the diaper 20 after the diaper is assembled together. Alternatively, the slots 74 are provided by adding sections of material to the side edges 30 of the diaper 20, which slots 74 extend laterally outward from the side edges 30 and connect only the sections of material to the side edges at their longitudinal ends. In this configuration, the material sections provide the side edges of the diaper and only the slits of the material sections to improve the manufacturing capacity.

In this configuration, a portion of the belt segment 68 between the slots 74 is secured to the interior surface 34 of the diaper 20 to provide a fixed portion 72. The fixed portion 72 of the belt section 68 may be secured to the inner surface of the diaper by methods known to those skilled in the art such as adhesive, sonic bonding or thermal bonding. Preferably, retaining portion 72 defines a retaining length 76, as shown in fig. 3, which retaining length 76 is less than about 75%, and preferably less than about 50%, of the overall length of band segment 68. This fixed length allows the belt segments to be adequately secured to the diaper 20 without affecting the ability of the belt segments to conform to the waist of the wearer to provide improved fit.

In another configuration, the belt segments 68 need not extend all the way through the diaper 20 to the interior surface 34. For example, a substantial portion of the belt segment 68 may extend between the outer cover layer 42 and the absorbent chassis 44, or between any component of the absorbent chassis, to further conceal the belt segment 68.

The belt segments 68 may be defined in any length and width to provide the desired improved fastening and fit about the wearer. For example, the belt segments 68 may define a length of from about 7 to about 35 centimeters and a width of from about 1 to about 10 centimeters. Preferably, the belt segments 68 define a length slightly less than the width of the diaper 20 at the respective waist region, so that the belt segments 68 are slightly extended to pre-stretch the waist region.

Materials suitable for use in the belt segments 68 of the various aspects of the present invention are similar to those described above for the outer cover layer 42. Preferably, the belt segments 68 are formed of an elastic material that is capable of being elongated by at least about 50%, and more preferably by at least about 100%, to provide an improved fit about the waist of the wearer. For example, the belt segments 68 may comprise a compression bonded laminate comprising KRATON film material commercially available from the Dow Chemical Company, an enterprise working in Midland Michigan. Alternatively, the belt segments 68 may include portions having elastic material and portions having non-elastic material. The belt segments 68 may also be made of a latent elastic material that activates the elasticity after the diaper 20 is made and before it is worn. In one particular embodiment, the belt segments 68 are made from a latent elastic material as described in U.S. patent application No. 08/854934, filed on 5/13 1997, entitled "improved composite elastic material and method of making the same", the disclosure of which is incorporated herein by reference.

The prefastened absorbent article of the various aspects of the invention also includes a pair of passive side bonds to enhance the security of maintaining the article in the prefastened condition, particularly when the article is pulled up or down over the hips of the wearer. For example, as representatively illustrated in fig. 1-4, the diaper 20 includes a pair of passive side bonds 80 and 82 which releasably connect the landing zone 84 or opposing ears 28 of the back waist region 24 to the front waist region 22 of the diaper 20. In this configuration, the passive side bonds 80 or 82 help the fastening system 60 maintain the diaper 20 in a pre-fastened state as the diaper 20 is pulled up or down over the hips of the wearer. Further, the passive side bonds 80 and 82 prevent the waist regions 22 and 24 and the ear regions 28 from shifting and shifting relative to each other to improve fit and performance. The passive side bonds 80 and 82 also provide improved hip coverage and prevent the side edges 30 and waist edges 32 of the prefastened diaper 20 from flipping over or folding over when the diaper is pulled on to the wearer. This prevention of inversion and folding reduces the degree of contact between the fastener and the wearer's skin, advantageously resulting in reduced skin irritation and erythema.

As shown in the illustrated embodiment, the passive side bonds 80 and 82 are located inward of the primary fasteners 62 at the back waist region 24 of the diaper 20. As used herein, the term "inwardly" refers to the distance in the transverse direction 40 from the respective component toward the longitudinal centerline 38 of the diaper 20. In this configuration, the passive side bonds 80 and 82 connect and stabilize the lap portions 84 of the back waist region 24 inwardly of the primary fasteners 62 with the front waist region 22. Preferably, the passive side bonds 80 and 82 join the headlap portion 84 of the back waist region 24 to the front waist region 22. For example, the passive side bonds 80 and 82 may bond the waist edge 32 and the side edge 30 of the back waist region 24 to the side edge 30 of the front waist region 22. In this configuration, the passive bonds 80 and 82 help prevent the side and waist edges 30 and 32 from flipping over when the diaper 20 is worn.

As shown in FIG. 4, the overlapped portion 84 of the back waist region 24 defines an overlap distance 88, which is the distance between the respective side edges 30 of the front and back waist regions 22 and 24 when the diaper is pre-fastened. The overlap distance 88 is important to ensure a good seal around the legs and waist of the wearer. Also, the greater the overlap distance 88, the further inward the passive bonds 80 and 82 are positioned, providing reduced relative movement between the front and back waist regions 22 and 24 and improved hip coverage during use. Also, a greater overlap distance 88 is desirable when handling the diaper 20 because the overlap portion 84 is generally folded over and joined to the opposing waist portion after the side bonds 80 and 82 are formed. To provide this improved fit and performance, the overlap distance 88 is preferably at least about 2.0 centimeters, and more preferably at least about 4.0 centimeters. As shown in FIG. 4, the passive bonds 80 and 82 may also be positioned a distance 94 of about 0.2 to about 2.5 centimeters inward from the side edges 30 at the opposite waist regions to improve attachment and performance.

In a particular embodiment, the headlap portion 84 of the back waist portion 24 is joined to the front waist portion 22 along its edges 30 and 32 by the passive bonds 80 and 82, but remains unattached to the front waist portion 22 between the edges 30 and 32 by the passive bonds 80 and 82. In this embodiment, the passive bonds 80 and 82 may further define an unsecured distance 90 on each side of the back waist region 24, the distance 90 being at least about 1.0 cm, and preferably at least about 2.0 cm, in the longitudinal direction 38 between the respective bond points. This arrangement is particularly useful when the fastening system 60 of the diaper 20 includes the belt segments 68 described above, and therefore, the belt segments 68 are allowed to slide freely within the sleeves 92 created between the passive bonds 80 and 82.

As shown in FIG. 4, the passive bonds 80 and 82 are positioned on the back waist region 24 a distance 86 inward from the primary fasteners 62 to prevent the front and back waist regions 22 and 24 from moving or shifting relative to each other. In a particular embodiment, at least one of the passive bonds 80 and 82 is positioned inward of the back waist region 24 a distance 86, the distance 86 being at least about 1.0 cm, and preferably at least about 2.0 cm. When the distance 86 is less than the above value, the front and back waist portions 22 and 24 may undesirably move relative to each other during use of the diaper 20. This movement of the respective waist regions 22 and 24 of the diaper 20 can in turn affect the fit of the diaper 20 on the wearer, thereby undesirably increasing leakage.

In some aspects of the invention, the passive side bonds 80 and 82 and the corresponding distance 86 and overlap distance 88 can be selectively varied by a tailor to accommodate the desired fit of the diaper 20 for different sized wearers. For example, the location of the bonds 80 and 82 may vary during the manufacturing process so that the same process can be used to produce prefastened diapers for conventional step 3 or step 4 sizes.

The passive side bonds 80 and 82 are attached in facing relationship to the respective front and back waist regions 22 and 24. For example, the passive side bonds 80 and 82 join the interior surface 34 of the diaper 20 in the back waist region 24 with the exterior surface 36 of the diaper 20 in the front waist region 22. Alternatively, the passive side bonds 80 and 82 join the interior surface 34 of the diaper 20 in the back waist region 24 with the front surface 34 of the diaper 20 in the front waist region 22. Such a configuration may result in improved throughput. In this configuration, the side edges 30 of the back waist region 24 are foldable when the primary fasteners 62 are engaged.

The passive side bonds 80 and 82 may be provided by any type of bond, such as heat, adhesive, and ultrasonic bonds and the like and combinations thereof as are known to those of ordinary skill in the art. The passive side bonds 80 and 82 may also be provided by suitable fasteners known to those of ordinary skill in the art, such as fasteners suitable for use as the primary fasteners 62. The passive side bonds 80 and 82 may be discrete point bonds, dashed lines, solid lines, interrupted lines, and the like or combinations thereof. Also, the side bonds 80 or 82 may have any shape, such as circular, square, triangular, and the like. In one embodiment, the passive side bonds 80 and 82 are preferably ultrasonic point bonds to improve manufacturing efficiency.

The use of passive bonds 60 and 62 and the method of making a prefastened diaper 20 in accordance with various aspects of the present invention are well known to those skilled in the art. For example, one such method, other than the manufacture of diapers by hand, is described in pending U.S. patent application entitled "method of making prefastened disposable absorbent articles" to Elsberg et al, attorney docket No. 13780, (International publication No. WO 99/65441), the disclosure of which is incorporated herein by reference.

The passive side bonds 80 and 82 are configured to help the primary fasteners 62 maintain the diaper 20 in a pre-fastened configuration when the diaper 20 is pulled up or down over the hips of the wearer and during use. Thus, it is preferred that the passive side bonds 80 and 82 provide sufficient shear strength to assist the primary fasteners 62. For example, in certain embodiments, the passive side bonds 80 and 82 define a shear strength of at least about 50 grams, and preferably at least about 100 grams. For example, the passive side bonds 80 and 82 may define a shear strength of from about 100 grams to about 4000 grams, and preferably from about 500 grams to about 2000 grams. As used herein, the term "shear strength" refers to the value obtained when the side bond is subjected to the shear strength test described herein. Shear strength values less than those described above do not prevent the front and back waist regions 22 and 24 from separating from each other during application and use of the diaper 20.

The passive side bonds 80 and 82 are also configured to tear easily so that a caregiver can easily remove the diaper 20 from the wearer after the diaper has been soiled. Thus, it is preferred that the passive side bonds 80 and 82 define a relatively low maximum peel strength so that a caregiver can easily detach the fasteners 62 and 64, tear the passive side bonds 80 and 82, and separate the front and back waist regions 22 and 24 to remove the diaper 20 from the wearer's waist in a manner similar to a conventional diaper that is not pre-fastened. For example, in certain embodiments, the passive side bonds 80 and 82 define a peel strength of no more than about 1500 grams, preferably no more than about 1000 grams, and more preferably no more than about 800 grams. The term "peel strength" as used herein refers to the value obtained when the side bond is subjected to the peel strength test described herein. Peel strength values greater than the above values are not easily torn and may disadvantageously result in tearing of other portions of the diaper 20. Preferably, the peel strength of the side bonds 80 and 82 is less than about 50% of the peel strength of the primary fastener 62, and more preferably less than about 20% of the peel strength of the primary fastener 62.

In another aspect, the present invention provides a package of the above-described prefastened disposable diaper. The package includes a package, such as a plastic bag, and a plurality of pre-fastened disposable diapers. As described above, the prefastened diaper 20 includes a pair of primary fasteners 62 and a pair of passive side bonds 80 and 82 which are disposed inwardly from the primary fasteners. Such a package provides a diaper which can be reliably pulled up over the legs of the wearer and which can be easily removed from the waist of the wearer after soiling.

Various aspects of the present invention advantageously provide a prefastened disposable absorbent article which includes the engagement of a passive side bond and an adjustable fastening system. The fastening system is prefastened to releasably engage the front and back waist regions to allow the absorbent article to be pulled up or down over the hips of the wearer, such as in conventional training pants. Moreover, the fastening system can be used to releasably engage and adjust the front and back waist portions of the absorbent article to maintain the absorbent article about the waist of the wearer after the article has been put on in a manner similar to a conventional diaper. The passive side bonds help the fastening system maintain the article in a pre-fastened state as the article is pulled up or down over the hips of the wearer. Moreover, the passive side bonds prevent the waist portions from moving and shifting relative to each other in order to improve fit and performance. The passive side bonds also prevent flipping or folding over the side edges and waist edges of the prefastened absorbent article as it is pulled over the hips of the wearer.

As a result, the absorbent article of the present invention is designed to conform to the body of the wearer to effectively contain body exudates while still being able to reliably pull the diaper up or down over the hips of the wearer to assist in toilet training of the wearer. Moreover, similar to conventional diapers, the absorbent articles of the present invention are advantageously relatively easy and clean to use and remove from a wearer.

Peel strength test

The test method is designed to determine the peel strength value in grams of an ultrasonic point bond that secures the front waist portion to the back waist portion of an absorbent article. In this application, the direction of removal (tearing) is the direction in which the fastener material is typically removed from the substrate when the product is in use. This direction is generally perpendicular to the longitudinal centerline of the product.

Device

1. A tensile tester capable of obtaining maximum loads and equipped with a suitable load cell. A suitable tensile testing system is the Sintech tensile tester, commercially available from MTS Sintech, Research Triangle Park, N.C., under the trade designation Instron model 4201 tensile tester having Sintech QAD (quality assurance division) software.

2. Software commercially available from MTS Sintech under the trade name Sintech Testworks^TMAnd (4) obtaining.

Puematic-action jig, commercially available from Instron, Canton, Mass under the trade designation "Instron Model 2712-.

4. A serrated 1/4 inch clamping surface, commercially available from Instron corporation, Canton, massachusetts.

5. The test apparatus had a temperature of 23. + -. 1 ℃ and a relative humidity of 50. + -. 2%.

Procedure of the test

1. The test specimens were placed in the test apparatus for at least 4 hours prior to testing.

2. The pressure sensor is calibrated and the software is installed.

3. The clamp is arranged on the tensile tester, and the clamp teeth are closed.

4. The test conditions of the tensile tester were set as follows.

Crosshead speed 500 mm/min

Full range load of 5 kg

The threshold value is 5%

Destruction standard 95%

Measuring length 50 mm

5. Weigh the clamp tare.

6. The primary fastener tab of the fastening element on the rear waist portion of the article is inserted into the upper jaw such that the edge of the gripping surface is flush with the inner edge of the hook material.

7. The front waist portion of the article is inserted into the lower jawset such that the inner surface of the rear waist portion and the outer surface of the front waist portion form an angle of 180. The lower jaw is closed.

8. The crosshead started running.

9. The maximum load of failure was recorded. The mode of expected failure is the separation of the back waist portion of the diaper from the front waist portion of the diaper. If the location of the failure is anywhere but ultrasonic point bonding, the results are discarded.

Shear strength test

The test method is designed to determine the maximum dynamic shear strength value in grams for ultrasonic point bonds that secure the front waist portion to the back waist portion of the absorbent article. In this application, the direction of the force is generally perpendicular to the longitudinal centerline of the product.

Device

1. A tensile tester capable of obtaining maximum loads and equipped with a suitable load cell. A suitable tensile testing system is the Sintech tensile tester, commercially available from MTS Sintech, Research Triangle Park, N.C., under the trade designation Instron model 4201 with Sintech QAD (quality assurance) software.

The pnuematic-action jig is commercially available from the Instron corporation of Canton, Mass under the trade designation "Instron Model 2712-.

4. A serrated 1/4 inch gripping surface, commercially available from Instron corporation of Canton, massachusetts.

Procedure of the test

2. The load cell is calibrated and the software is installed.

3. The clamp is arranged on the tensile tester, and the clamp teeth are closed.

4. The test conditions used in the tensile tester were set as follows.

Crosshead speed 500 mm/min

Full range load of 5 kg

The threshold value is 5%

Destruction standard 95%

Measuring length 50 mm

5. Weigh the clamp tare.

7. The front waist portion of the article is inserted into the lower pincer so that the inner surface of the rear waist portion and the outer surface of the front waist portion face in the same direction and are parallel to each other. The lower jaw is closed.

8. The crosshead started running.

9. The maximum load of failure was recorded. The mode of expected failure is the separation of the back waist portion of the article from the front waist portion of the article. If the location of the failure is anywhere but ultrasonic point bonding, the results are discarded.

While the invention has been described in detail with respect to specific aspects thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these aspects. Accordingly, the scope of the invention should be determined by the appended claims and any equivalents thereof.

Claims

1. A prefastened disposable absorbent article which defines an absorbent, a front waist region, a back waist region, a crotch region extending between and interconnecting said waist regions, and a pair of opposed side edges, wherein said prefastened absorbent article comprises:

a) a pair of primary fasteners positioned on said opposite side edges in one of said waist regions and in overlapping releasable engagement with said opposite waist regions of said prefastened absorbent article to provide said prefastened absorbent article; and

b) a pair of passive side bonds located inboard of said primary fasteners on said one waist region and releasably attaching overlapping portions of said one waist region to said opposing waist region to help maintain said prefastened absorbent article in a prefastened condition; wherein the content of the first and second substances,

the passive side bond is positioned on the one waist portion at a distance of at least 1.0 cm inward from the primary fastener.

2. The absorbent article of claim 1 wherein said primary fastener is a hook and loop fastener.

3. The absorbent article of claim 1, further comprising at least one attachment tab positioned in the opposing waist region, the primary fastener being configured for releasable engagement with the attachment tab.

4. The absorbent article of claim 1 further comprising a pair of secondary fasteners positioned on said one waist region and configured to releasably engage said opposite waist region after said prefastened absorbent article is pulled up over the hips of the wearer to thereby conform said waist region to the hips of the wearer.

5. The absorbent article of claim 1 wherein said primary fasteners are positioned on said opposite side edges in said back waist region of said absorbent article and releasably engage said front waist region to provide said prefastened absorbent article.

6. The absorbent article of claim 1 wherein said passive side bond releasably connects said landing zone portion of said one waist region to said side edge of said opposing waist region to assist in maintaining said prefastened absorbent article in a prefastened condition.

7. The absorbent article of claim 6 wherein said passive side bonds releasably join one waist edge and said side edges in said one waist region to said opposing waist region but do not bond said overlap portion of said one waist region between said waist edge and said side edges of said opposing waist region.

8. The absorbent article of claim 1 wherein said overlap portion of said one waist region defines an overlap distance of at least 2.0 centimeters.

9. The absorbent article of claim 1 wherein said passive side bonds comprise at least one point bond.

10. The absorbent article of claim 9 wherein said point bonds are ultrasonic point bonds.

11. The absorbent article of claim 1 wherein said passive side bonds define a peel strength of no more than 1500 grams.

12. The absorbent article of claim 1 wherein said passive side bonds join an inner surface of said absorbent article in said one waist region to an outer surface of said absorbent article in said opposite waist region.

13. The absorbent article of claim 1 wherein said passive side bond joins an interior surface of said absorbent article in said one waist region to an interior surface of said absorbent article in said opposite waist region.

14. A prefastened disposable absorbent article which defines an absorbent, a front waist region, a back waist region, a crotch region which extends between and connects said waist regions and a pair of opposed ear regions which are located in one of said waist regions and which overlap the opposed waist region, wherein said absorbent article comprises:

a) a pair of primary fasteners positioned on said opposing ears on said one waist region and releasably engaging said opposing waist regions of said absorbent article to provide said prefastened absorbent article;

b) a belt segment defining opposite ends and positioned at the one waist portion;

c) a pair of secondary fasteners positioned on said opposite ends of said belt segments, the secondary fasteners being configured for releasable engagement with said opposite waist regions after said prefastened absorbent article is pulled up over the hips of the wearer to conform said waist regions to the body of the wearer; and

d) a pair of passive side bonds positioned on the opposing ears inboard of the primary fasteners; the passive side bond releasably connects the landing portion of the ear portion to the opposing waist region to help maintain the prefastened absorbent article in a prefastened condition.

15. The absorbent article of claim 14 wherein said primary fasteners are positioned on said ears in said back waist region of said absorbent article and releasably engage said front waist region to provide said prefastened absorbent article.

16. The absorbent article of claim 14 wherein said passive side bonds releasably bond said landing zone portion of said ear portion to a pair of opposing side edges of said absorbent article in said opposing waist region.

17. The absorbent article of claim 14 wherein said passive side bond is discontinuous along one longitudinal length of said ear portion.

18. The absorbent article of claim 17 wherein said passive side bonds define an unsecured longitudinal length of at least 1.0 cm to form a sleeve through which said belt segments are slidable.

19. The absorbent article of claim 14 wherein said passive side bonds are positioned on said ears a distance of at least 1.0 cm inward from said primary fasteners.

20. The absorbent article of claim 14 wherein said overlap portion of said ear portion defines an overlap distance of at least 2.0 centimeters.

21. The absorbent article of claim 14 wherein said passive side bonds comprise ultrasonic point bonds.

22. The absorbent article of claim 14 wherein said passive side bonds define a peel strength of no more than 1500 grams.

23. The absorbent article of claim 14 wherein said passive side bonds join an inner surface of said absorbent article in said one waist region to an outer surface of said absorbent article in said opposite waist region.

24. The absorbent article of claim 14 wherein said passive side bond joins an interior surface of said absorbent article in said one waist region to an interior surface of said absorbent article in said opposite waist region.

25. The absorbent article of claim 14 further comprising at least one attachment panel positioned at the opposing waist regions, the primary and secondary fasteners being configured for releasable engagement with the attachment panel.

26. The absorbent article of claim 14, wherein said absorbent article further comprises an outer cover layer comprising a nonwoven material.

27. The absorbent article of claim 26 wherein said primary fasteners and said secondary fasteners are hook-type fasteners configured for releasable engagement with said outer cover.

28. The absorbent article of claim 14 wherein the belt segments comprise an elastic material capable of being elongated at least 100%.

29. The absorbent article of claim 14 wherein said belt segment is attached to an inner surface of said absorbent article in said one waist region.

30. The absorbent article of claim 29 wherein said opposite ends of said belt segments extend through a slot in said one waist region on an outer surface of said absorbent article in said one waist region.

31. The absorbent article of claim 14 wherein said secondary fasteners and said opposite ends of said belt segments are shaped to extend over said primary fasteners for releasable engagement with said opposite waist regions of said absorbent article to conform said waist regions to the body of the wearer after said prefastened absorbent article is pulled up over the hips of the wearer.

32. A prefastened disposable absorbent article defining a front waist region, a back waist region, a crotch region extending between and interconnecting said waist regions and a pair of opposed side margins, said absorbent article comprising

a) An outer cover layer;

b) an absorbent chassis including a back sheet attached to said outer cover, a body side liner attached in superposed relation to said back sheet, and an absorbent core disposed between said back sheet and said body side liner;

c) a pair of primary fasteners positioned on said outer cover on said laterally opposing side edges of said back waist region of said absorbent article, said primary fasteners being shaped for releasable engagement with an outer surface of said absorbent article in said front waist region of said absorbent article;

d) a belt segment positioned at said rear waist portion of said absorbent article and defining a pair of opposed ends;

e) a pair of secondary fasteners positioned on said opposite ends of said belt segments, the secondary fasteners being configured for releasable engagement with said outer surface of said front waist region after said prefastened absorbent article is pulled up over the hips of the wearer to further conform the waist region to the body of the wearer;

f) a pair of passive side bonds positioned inboard of the primary fasteners on the back waist region, the passive side bonds releasably connecting overlapping portions of the back waist region to the front waist region to assist in maintaining the prefastened absorbent article in a prefastened condition.

33. The absorbent article of claim 32 wherein said passive side bonds join said overlapped portion of said back waist region with said side edges of said front waist region to help maintain said pre-fastened absorbent article in said pre-fastened condition.

34. The absorbent article of claim 32 wherein said passive side bonds releasably join one waist edge and said side edges in said back waist region to said front waist region but do not bond said overlap portion of said back waist region between said waist edge and said side edges of said front waist region.

35. The absorbent article of claim 34 wherein said passive side bonds define an unsecured longitudinal length of at least 1.0 cm to form a sleeve through which said belt segments are slidable.

36. The absorbent article of claim 32 wherein said passive side bond is positioned on said back waist region inward from said primary fastener by a distance of at least 1.0 cm.

37. The absorbent article of claim 32 wherein said overlapped portion of said back waist region defines an overlap distance of at least 2.0 centimeters.

38. The absorbent article of claim 32 wherein said passive side bonds define a peel strength of no more than 1500 grams.

39. The absorbent article of claim 32 wherein said passive side bonds join an interior surface of said absorbent article in said back waist region to an exterior surface of said absorbent article in said front waist region.

40. The absorbent article of claim 32 wherein said passive side bonds join an interior surface of said absorbent article in said back waist region to an interior surface of said absorbent article in said front waist region.

41. A prefastened disposable absorbent article which defines an absorbent, a front waist region, a back waist region, a crotch region which extends between and connects said waist regions and a pair of opposed side margins, wherein said absorbent article comprises:

a) a pair of primary fasteners positioned on said opposite side edges in one of said waist regions, said primary fasteners being releasably engageable with opposite waist regions of said disposable absorbent article to define a waist circumference dimension;

b) a waist size adjustment device for reducing the waist size of the absorbent article without loosening the primary fasteners to conform the waist to the body of the wearer after the pre-fastened absorbent article has been pulled up;

c) a pair of passive side bonds positioned inboard of said primary fasteners on said one waist region and releasably attaching an overlapping portion of said one waist region to said opposing waist region to assist said pre-fastened absorbent article in maintaining said pre-fastened condition.

42. The absorbent article of claim 41, wherein said waist size adjustment means comprises:

a) a belt segment positioned at one of said waist portions and defining opposite ends; and

b) a pair of secondary fasteners positioned on said opposite ends of said belt segments, the secondary fasteners being shaped for releasable engagement with said opposite waist regions to conform said waist regions to the body of the wearer.

43. The absorbent article of claim 41 wherein said passive side bond is positioned at said one waist region a distance of at least 1.0 cm inward from said primary fastener.

44. The absorbent article of claim 41 wherein said overlap portion of said one waist region defines an overlap distance of at least 2.0 centimeters.

45. The absorbent article of claim 41 wherein said passive side bonds define a peel strength of no more than 1500 grams.

46. The absorbent article of claim 41 wherein said passive side bond joins an inner surface of said absorbent article in said one waist region to an outer surface of said absorbent article in said opposite waist region.

47. The absorbent article of claim 41 wherein said passive side bond joins an interior surface of said absorbent article in said one waist region to an interior surface of said absorbent article in said opposite waist region.