CN1384730A - Absorbent article having vertically orientated flow regulating walls and method for forming - Google Patents

Abstract

Absorbent pad assemblies and articles are provided which include at least a first generally planar fluid conveyance barrier member of preselected permeability interposed between first and second vertically orientated absorbent members. Also provided is a method for forming an absorbent structure wherein a fluid conveyance barrier member of preselected permeability is adjacently disposed between first and second absorbent members with the barrier member and the first and second absorbent members orientated such that as to have a specifically desired ratio of horizontal width to vertical height.

Description

Absorbent article having vertically oriented flow regulating walls and method of forming same

technical field

The present invention generally relates to absorbent articles for absorbing body fluids and exudates. In particular, the present invention relates to absorbent pad assemblies having improved fluid flow control or management and related absorbent articles and methods of forming the same.

Background technique

A large variety of structures are known in the art for or as absorbent articles, particularly disposable absorbent articles, which are used to collect various body fluids and exudates. Commercially available absorbent articles include diapers, adult incontinence products, sanitary napkins and bandages. Disposable products of this type typically include components for receiving, absorbing and retaining fluids. Typically, the components of such an article include a liquid-permeable topsheet, an absorbent core and a liquid-impermeable backsheet.

The components of a typical absorbent article are generally layered or arranged in a horizontal fashion with a major planar surface facing the fluid intake zone, such as the wearer's body. In such absorbent articles, the nature or structure of the fluid transport throughout can, and often does, vary as the fluid traverses one or more layers. As such, such absorbent articles may exhibit undesired level dependencies between components. Also, the fibers that typically make up the absorbent core are often randomly oriented, the fibers being arranged laterally adjacent within the pad, and thus, the intake of fluid is typically wicked in a radial fashion or pattern.

One of the main goals in the development of absorbent articles is to increase, enhance or maximize the absorbent capacity of the article. In general, products of the type described above typically distribute the liquid deposited on the topsheet in a circular pattern. Since such structures generally have a length that is greater than their width, this may undesirably result in fluids such as exudates reaching the longitudinal side edges of the absorbent article before the end regions of the absorbent article have utilized the absorbent capacity as desired. It will be appreciated that the occurrence of the above may undesirably increase the likelihood of leakage from the sides of the article despite underutilization or underutilization of the absorbent capacity of the end regions of the absorbent article.

Moreover, such absorbent articles are capable and adaptable to a wide range of conditions and applications, such as factors inherent or related to the environment in which the article is used. As such, the fluid that may need to be absorbed may vary in nature or parameters including, for example, flow rate and form, phase or composition. For example, the effluent can be heterogeneous and heterogeneous, such as in the case of menses, which can include, for example, red blood cells, mucin, plasma and tissue debris.

Sanitary napkins (also known as menstrual pads), feminine pads, night pads, panty liners, and panty shields are designed to be worn by women to absorb menstrual and other bodily fluids before, during, and after menstruation . Sanitary napkins are external devices designed to be brought into close proximity and alignment with the vulvar area of the body and are usually held in place by adhesive or mechanical attachment to underwear. Sanitary napkins also typically differ from panty liners and panty shields in several significant ways. Compared to panty liners and panty shields, sanitary napkins are generally larger in size, have a more defined three-dimensional configuration, are thicker, and have greater fluid capacity.

Given the desire for absorbent articles to provide increased comfort to the wearer and minimize the profile in which such absorbent articles exist, there is an ongoing need and demand for smaller or compact absorbent articles. Thus, there is a need and a demand for improved absorbent pad assemblies and absorbent articles which, for example, can result in a more complete utilization of their absorbent capacity and, for example, can respond more effectively and efficiently to a wider range of possible operating and use conditions. and products under the operating and use conditions. In particular, there is an ongoing need and demand for an absorbent pad assembly and absorbent article having improved control or management of fluid flow associated therewith.

Contents of the invention

A primary object of the present invention is to provide an improved absorbent pad assembly and absorbent article. Another primary object of the present invention is to provide a method of shaping an absorbent structure such as either or both an improved absorbent pad assembly and absorbent article.

A more specific object of the invention is to solve one or more of the above-mentioned problems.

One of the main objects of the present invention is achieved, at least in part, by a specific absorbent pad assembly. According to a preferred embodiment, the absorbent pad assembly includes at least one first generally planar fluid transport barrier of preselected permeability sandwiched between first and second perpendicularly oriented between absorbent pieces.

The prior art generally fails to provide absorbent pad assemblies and absorbent articles that fully or fully utilize their absorbent capacity at will. The prior art has generally failed to provide absorbent pad assemblies and absorbent articles that are responsive to possibly the wider range of operating and use conditions under which they are placed and at will in a more effective and efficient manner operate.

The present invention also includes a specific absorbent article. According to a preferred embodiment of the present invention, the absorbent article has a contact surface and includes an absorbent pad assembly. The absorbent pad assembly includes at least first and second generally planar fluid transport barriers. Each barrier member has a preselected permeability and is sandwiched between a pair of absorbent members disposed generally perpendicularly with respect to the contacting surface.

Another aspect of the present invention relates to specific methods of forming such and similar absorbent structures. According to one embodiment, one such method comprises adjacently disposing at least one first generally planar fluid transport barrier of preselected permeability between at least first and second absorbent members, and causing the adjacently disposed barrier and the first and second absorbent members are oriented, wherein the first and second absorbent members each have a horizontal width to vertical height ratio of not more than about 10:1.

According to another embodiment, a method of forming an absorbent pad assembly is provided. The method comprises horizontally layering at least one pre-permeably permeable first generally planar fluid transport barrier between first and second absorbent members, and layering the horizontally layered barrier with the first and second absorbent members. The pieces are reoriented vertically.

According to another embodiment, there is provided a method for improving fluid handling by an absorbent article comprising a liquid-permeable cover, a liquid-impermeable backsheet, and an absorbent sheet disposed between the cover and the backsheet. pad assembly. The method comprises utilizing an absorbent pad assembly comprising a fluid transport barrier having a first generally planar surface of preselected permeability sandwiched between a pair of absorbent members disposed generally perpendicularly with respect to the contacting surface . As described in more detail below, a particular form of such absorbent article is the sanitary napkin.

As used herein, reference to an "absorbent article" is understood to mean products such as diapers, sanitary napkins, training pants, incontinence garments, night pads, panty liners, underarm shields, etc., which are used to absorb expelled Body fluids and discharges such as urine, menses, blood, perspiration and other excretions.

Also, "vertical orientation" here in relation to an absorbent is understood as a general arrangement of components and generally relates to the body contacting surface or the face of the absorbent article itself. Generally, a vertically oriented absorbent member is understood to have a horizontal width to vertical height ratio of not more than about 10:1, preferably not more than about 5:1, more preferably about 1:1 or less.

"Discontinuity" herein in relation to adjacent absorbent members is understood to mean that adjacent absorbent members form or have a surface interface therebetween. It will be appreciated that, in practice, such surface interfaces serve to impede, prevent or avoid the passage of fluid between adjacent absorbent members or from one absorbent member to another adjacent absorbent member. It will be appreciated and will be described in more detail below that adjacent absorbent members preferably differ in one or more properties or characteristics, such as chemical composition or structure, such as fiber orientation or thickness. It will be apparent to those of ordinary skill in the art that adjacent absorbent members may differ in other useful properties or characteristics given the teachings provided herein.

Formation of a "surface interface" therebetween in relation to adjacent absorbent members is here understood to mean a surface formed between adjacent parts in contact or mutual proximity.

"Contact surface" as referred to herein is understood to mean the surface of the absorbent member, pad assembly, article or the like which initially comes into contact with absorbed fluid.

Other objects and advantages of the present invention will be apparent to those skilled in the art from the following detailed description in conjunction with the claims and drawings.

Description of drawings

Figure 1 is a schematic exploded perspective view of an absorbent article having a pad assembly according to a preferred embodiment of the present invention;

Figure 2 is a partially cutaway perspective view of the absorbent article shown in Figure 1;

Figure 3 is a simplified cross-sectional side view of the absorbent article shown in Figures 1 and 2;

4-6 are schematic simplified partial top views of an absorbent article according to an alternative embodiment of the present invention; and

Figures 7-9 are schematic simplified cross-sectional side views of an absorbent article according to an alternative embodiment of the present invention, seen along the X-X axis.

Detailed ways

As described in detail below, the present invention provides an improved absorbent pad assembly and absorbent article and a method of forming such an absorbent product.

Referring initially to Figures 1-3, there is illustrated an absorbent article, generally indicated at 30, which is capable of absorbing body fluids, in accordance with one embodiment of the present invention. The absorbent article may be a diaper, training pants, sanitary napkin, panty liner, night pad, incontinence garment, underarm shield, or other type of absorbent product that is capable of absorbing one or more body fluids, such as urine, menses, Blood, perspiration, excrement, etc. It will be appreciated that the typical nature of such absorbent articles is single use. Although the absorbent article 30 is described herein in terms of feminine care products such as sanitary napkins, it will be appreciated that the broader applicability of the present invention is not necessarily so limited, and that the present invention may be applied to or combined with other types or forms of absorbent articles such as the above Certain absorbent articles are associated.

The absorbent article 30 comprises a generally liquid-permeable topsheet or cover 32 on the bodyside surface of the product, a generally liquid-impermeable backsheet or barrier 34 on the opposite, garment-facing side of the product, and a disposing and packaging The absorbent core 35 therebetween.

It will be appreciated that absorbent articles such as feminine care products such as sanitary napkins may typically include additional standard or customary features, for example with respect to the orientation or position of the article in use. For example, some sanitary napkin designs feature side panels, sometimes referred to as "wings," such as to help prevent fluids from exiting the sides of the sanitary napkin. Another example of such a feature is the inclusion or presence of adhesive on or around the garment-facing region surface of the backsheet. The adhesive surface of such articles may be covered with release paper or the like prior to use, eg in the packaged state, as is known in the art. Since such features are standard or commonly used, are well known to those of ordinary skill in the art and do not form part of the broader invention, they are not shown or illustrated in detail herein.

The topsheet or cover layer 32 is generally designed to be in contact with the user's body and generally forms the contacting surface of the absorbent article 30 . In practice, the topsheet 32 can be constructed of woven or nonwoven materials, made of synthetic or natural materials, and is preferably readily penetrated by bodily fluids. Suitable materials include bonded carded coverings of polyester, polypropylene, polyethylene, nylon or other thermally bonded fibers. Other polyolefins such as copolymers of polypropylene and polyethylene, linear low density polyethylene, microporous film coverings and mesh materials also work well. The topsheet 32 may also be constructed of a thermoplastic film containing apertures with a nonwoven on one or both sides. This embodiment ideally provides a softer feel to the user's thighs while allowing bodily fluids to pass through quickly.

The backsheet or barrier layer 34 is generally liquid impermeable and is designed to face the inner surface of an adjacent article of clothing, such as the crotch of an undergarment (not shown). The backsheet 34 may preferably be designed to allow air or vapor to pass through and out of the absorbent article 30, while preventing or hindering the passage of fluids. It will be appreciated that the backsheet 34 may be formed from any suitable material that provides or possesses the properties or characteristics identified above. For example, suitable materials may include microembossed polymeric films such as polyethylene or polypropylene.

In general, the topsheet 34 and the backsheet 34 may be disposed coextensively in face-to-face contact around or surrounding the absorbent core 35 . Also, the topsheet 32 has a perimeter 32a, and the backsheet 34 has a perimeter 34a, which perimeters are preferably joined or sealed together using an adhesive by heat sealing, ultrasonic or other suitably selected techniques known to those of ordinary skill in the art.

The absorbent core 35 is at least partially formed from an absorbent pad assembly 36 . As shown in Figures 2 and 3, the absorbent pad assembly is a three-dimensional structure having a horizontal axis X-X, a vertical axis Z-Z, and a length axis Y-Y. The absorbent pad assembly 36 includes a number of vertically oriented absorbent members 40, 42, 44, 46, 48, 50, 52, 54, and 56, respectively.

In practice, absorbent pad assemblies according to the present invention typically include at least two, and preferably at least three, such vertically oriented absorbent members. It will be appreciated that the particular number or nature of absorbent members to be included in an absorbent pad assembly according to the present invention will generally be selected by one of ordinary skill in the art, and taught herein, in order to meet the requirements or requirements of the particular application to which the assembly is concerned. ideal performance standards. For example, absorbent members having the same or different materials, constructions or absorbent characteristics or characteristics may be utilized such that two or more or even all of the absorbent members constitute a particular absorbent pad assembly of the present invention. In general, however, in order to more fully realize the possible advantages of an absorbent pad assembly with multiple absorbent members, an absorbent pad assembly according to the present invention will comprise at least two absorbent members having different materials, constructions or absorbent characteristics or characteristics .

A first generally planar fluid transfer barrier or fluid flow regulating wall 41 is sandwiched between absorbent members 40 and 42 as shown. Similarly, a generally planar fluid transfer barrier or fluid flow regulating wall 43 is sandwiched between absorbent members 42 and 44 . Also, generally planar fluid transport barriers 45, 47, 49, 51, 53 and 55 are sandwiched between different adjacent pairs of absorbent members 44 and 46, 46 and 48, 48 and 50, 50 and 52, 52 and 54 and between 54 and 56. It will be appreciated that the barriers are generally each disposed vertically relative to the contacting surface of the absorbent article 30 .

The barriers (hereinafter also sometimes referred to as "flow regulating walls" or "fluid flow regulating walls") can take different forms and have a particularly preselected permeability. Furthermore, such barriers may be employed in absorbent pad assemblies and absorbent articles in special or special configurations to provide or result in special or special fluid flow control or treatment.

For example, one or more barrier members employed in the absorbent pad assemblies and absorbent articles of the present invention may be controlled or adjusted as semi-permeable or liquid-impermeable materials, as may be particularly desired for a particular application or use. Alternatively or additionally, one or more of the barriers employed in the absorbent pad assemblies and absorbent articles of the present invention may be a fluid flow directing material.

The barriers used in the practice of the present invention may be fabricated or formed from various suitable materials of preselected permeability, such as are known in the art. Depending on the particular application, suitable impermeable barriers include, for example, coatings or films that prevent fluid transport therethrough. For example, such an impermeable coating or film may be applied to a suitable substrate, eg, to form an impermeable barrier. Depending on the particular application, another suitable impermeable barrier includes, for example, the impermeable backsheet materials described above, or non-absorbent foams, such as closed-cell, cross-linked or non-cross-linked polyolefin foams, comprising, for example, poly Propylene or polyethylene foam. Examples of commercially available foams intended for use in the present invention include foams manufactured under the trade designation CA-30 by Sealed Air Corp. of FairLawn, New Jersey, and Astro-Valcour, Inc. of Glens Falls, New York. .The trade name manufactured is AF-030 foam material.

A semi-permeable barrier may be made of a material that only allows certain fluids to be transported therethrough. For example, the contents of such semi-permeable barriers can be used to filter or screen fluids transported therethrough. Depending on the particular application, suitable semi-permeable barriers may include porous or apertured films, or mesh materials such as those described in U.S. Patent 4,616,644 to Saferstein et al. and U.S. Patent 5,643,240 to Jackson et al., the disclosures of which are in their entirety. Provided here for reference. For example, U.S. Patent 4,616,644 discloses a series of lightweight nonwoven fabrics made from high density polyethylene or polypropylene by extrusion, embossing, and orientation and known as Delnet films available from Hercules Inc., U.S. Patent 5,643,240 discloses a suitably apertured film known as AET polyethylene CKX 215 film made by Applied Extrusion Technology of Middleton, Del.

A directional or flow directional barrier acts like a check valve to allow fluid to pass therethrough primarily in one direction. For example, an apertured film such as is known for use as the top or bodyside surface in the absorbent article is used for this purpose.

As such, the barriers used in the practice of the present invention may be made of various films, foams and the like. Furthermore, according to certain preferred embodiments of the present invention, the one or more barriers may take the form of a film, foam or the like, and may be dissolvable upon fluid contact, for example to provide or cause a time releaser effect.

Thus, in the absorbent article 30 shown in Figures 1-3, the barriers 45, 47, 49, and 51 are substantially liquid impermeable, eg, prevent or prevent fluid from passing therethrough. Barriers 43 and 53 are semi-permeable. That is, the semi-permeable barrier 43 allows selected fluids to flow in the direction from the absorbent 42 to the absorbent 44 or in the opposite direction. Similarly, semi-permeable barrier 53 allows selected fluids to flow in the direction from absorbent 52 to absorbent 54 or in the opposite direction. Additionally, barriers 41 and 55 are flow oriented. That is, the barrier 41 allows fluid to flow in the direction from the absorbent 40 to the absorbent 42, but not in the opposite direction. Similarly, barrier 55 allows fluid to flow from absorbent 56 to absorbent 54, but not in the opposite direction. In FIG. 3 , the flow directing properties of the barriers 41 and 55 are schematically represented by the cone 57 shown in FIG. 3 . As shown, each cone 57 includes an apex 58 pointing in a direction to direct flow. Adjacent to or around one or more terminal absorbent members of a particular absorbent pad assembly, the use of fluid flow directional barriers helps to better ensure that fluids are not spilled beyond the edges of the pad assembly and/or to increase the presence of fluid in the pad assembly. Absorbent utilization. It will be appreciated, however, that many different particular configurations of barriers and absorbers according to the invention are possible and that the broader scope of the invention is generally not limited to specific or particular such configurations. For example, if desired, one or more such fluid flow directional barriers can be positioned and oriented so as to direct fluid toward the edges rather than the center of the corresponding absorbent pad assembly.

Furthermore, one or more barrier members according to the present invention may be vertically co-extensive with adjacent associated absorbent members, such as barrier members 41 , 43 , 47 , 49 , 53 and 55 . Alternatively or additionally, one or more barrier members according to the present invention may be vertically non-coextensive with adjacent absorbent members, for example barrier member 45 relative to adjacent absorbent members 44 and 46, respectively, barrier member 51 relative to adjacent absorbent members, respectively. Adjacent absorbent members 50 and 52. Thus, adjacent absorbent members 44 and 46 form a surface interface 60 therebetween, while adjacent absorbent members 50 and 52 form a surface interface 62 therebetween. In preferred embodiments, the surface interfaces 60 and 62 are generally positioned on the side of the absorbent article 30 opposite the contacting surface as shown by the cover 32 , eg, adjacent to or near the backsheet 34 . It will be appreciated, however, that the broader scope of the invention need not be so limited.

Surface interfaces 60 and 62 allow fluid transfer or communication from one adjacent absorbent member to another. It will be appreciated that such structures or arrangements can be used to facilitate more complete utilization of the absorbent capacity of a particular absorbent pad assembly. For example, according to some preferred embodiments of the present invention, fluid will communicate across the surface interface, typically only after the absorbent capacity of one or the other adjacent absorbent member has been fully utilized.

As shown, otherwise adjacent absorbent members are horizontally displaced relative to each other along their entire vertical height. That is, no part of the otherwise adjacent absorbent member generally has the same position on the X-X axis. For example, no portion of the absorbent member 40 underlies or has the same X-X axis position as a portion of an adjacent absorbent member 42 .

Each absorbent member 40 , 42 , 44 , 46 , 48 , 50 and 52 is generally planar and is disposed vertically relative to the contact surface of the absorbent article 30 . Each absorbent member has a vertical height (h), a horizontal width (w) and a longitudinal length (l). It will be appreciated that the particular height, width and length of the absorbent used will generally be selected to meet the specific requirements of such absorbent application. Absorbent members used in the practice of the present invention typically have a width in the range of about 0.03 mm to no more than about 20 mm, and a height of about 1 mm to about 15 mm. However, in practice, the absorbent member used in the present invention typically has a width of no more than about 8 mm (for example, in the range of about 0.5 mm to about 8 mm), preferably, a width of no more than about 5 mm (for example, in the range of about 1mm to about 5mm).

Additionally, one or more of the vertical height, horizontal width, and longitudinal length of a particular absorbent element may be the same or different from the corresponding dimensions of other absorbent elements or components of a particular pad assembly. For example, as shown in FIG. 1 , the side-located absorbent members 56 are shorter in length (1) than the centrally-located absorbent members, such as absorbent members 46 , 48 and 50 . Also, as shown in FIG. 3 , the absorbent member 42 has a greater width (w) than the absorbent member 44 . Similarly, although Figure 3 shows each absorbent member having substantially the same vertical height (h), although this use may facilitate manufacturing and assembly and thus is generally preferred, it is also possible to use different or selected vertical heights (h). Highly absorbent piece.

According to some preferred embodiments of the present invention, one or more of the vertical height, horizontal width and longitudinal length of a particular absorbent member may vary or be constant and uniform for the entire absorbent member as required in a particular application. Also, in those absorbent members that vary in one or more of vertical height, horizontal width and longitudinal length, such variation may be continuous or in one or more steps. And, if present, this variation can be uniform or non-uniform, as desired.

According to the invention, the absorbent member is advantageously arranged, for example generally providing a lower aspect ratio than is generally obtained or achieved in absorbent articles such as sanitary napkins. This absorbent construction with a significantly low aspect ratio promotes wicking in the direction of the Y-Y and Z-Z axes because fluid prefers to flow towards the fibers near the interface rather than across between adjacent absorbents. The vertically arranged surface interface flow formed between them.

Furthermore, the vertical orientation of adjacent absorbent members according to the present invention allows absorbent pad assemblies and associated absorbent articles to be designed to facilitate the use of a selected variety of absorbent materials proximate to the fluid intake zone. Those of ordinary skill in the art will appreciate that at least some absorbent articles comprising different feminine care products, for example comprising sanitary napkins, may need to be associated with fluids having a different or wide variety of possible ingredients in order to be satisfactorily used. Thus, the development of the improved absorbent pad assembly and absorbent article of the present invention is a great improvement in the art because of the possible variety of different absorbent materials therein that can be conveniently located near the fluid intake zone. Furthermore, the absorbent pad assembly and absorbent article of the present invention advantageously avoid the complications associated with the above-mentioned level dependence.

According to a preferred embodiment of the present invention, the absorbent member preferably has an aspect ratio of less than 1 in order to more fully realize the benefits of the specifically oriented absorbent member of the absorbent pad assembly and absorbent article of the present invention.

Although the height and width of each absorbent member of the absorbent pad assembly 36 are the same, it is understood that the wider application of the present invention is not necessarily so limited, and the present invention can employ absorbent members of different heights, widths, or both, if desired. .

Absorbent members useful in the practice of the present invention may be made or formed from, for example, any suitable absorbent material known in the art. For example, selected absorbent members useful in the practice of the present invention may be made or formed from a variety of hydrophilic natural or synthetic fibers including cellulose fibers, surfactant-treated meltblown fibers, wood pulp fibers , Regenerated fiber, cotton fiber or a mixture of other fibers.

The construction of the absorbent material may include commonly known coform materials as described in US Patent 4,100,324. Coforms are available from the Kimberly-Clark Company of Neenah, Wisconsin, and are typically nonwovens made from an air-formed matrix of thermoplastic polymeric fibers and a variety of separately processed wood pulp fibers, and it has a fabric-like trim noodle. Thermoplastic fiber polymers typically have an average diameter of less than 10 microns, and the individually processed wood pulp fibers are uniformly dispersed on the substrate and serve to separate the microfibers from one another. This material is initially formed using a primary air stream with meltblown microfibers and a secondary air stream containing wood pulp fibers, and the two air streams are combined under turbulent conditions to form a combined air stream along the forming surface.

In some embodiments, it is desirable to use an absorbent material having the properties of a surge material. A variety of woven fabrics and nonwoven coverings can be used to construct surge materials. For example, the surge material may be a nonwoven layer of meltblown or spunbond coverstock of polyolefin filaments. Such nonwoven fabric layers may include staple fibers or other lengths of conjugate fibers, biconstituent fibers and homopolymer fibers, and mixtures of these fibers with other types of fibers. Fluid treated fibers may also be a bonded carded cover or an airlaid cover composed of natural and/or synthetic fibers. The bonded carded web may for example be a powder bonded carded web, an infrared bonded carded web or a breathable bonded carded web. The bonded carded cover may optionally comprise a mixture or blend of different fibers, the fiber lengths in the selected cover may range from about 3 mm to about 60 mm.

Examples of specific surge materials can be found in US Patent 5,490,846 to Ellis et al. and US Patent 5,364,382 to Latimer. The surge material may consist of a substantially hydrophobic material which may optionally be treated with surfactants or otherwise treated to achieve a desired degree of wettability and hydrophilicity.

Another possible suitable absorbent material is that known as PRISM available from Kimberly-Clark Corporation. PRISM is described and taught in US Patent 5,336,552 to Strack et al., the disclosure of which is incorporated herein by reference in its entirety. A PRISM is typically a nonwoven fabric comprising an extruded multicomponent polymeric strand comprising first and second polymeric components arranged in substantially distinct regions across the cross-section of the multicomponent strand, and Extends continuously along the length of the multi-component bundle. Preferably, the bundle is a continuous filament formable by spunbonding techniques. The second component of the bundle constitutes at least a portion of the peripheral surface of the multicomponent bundle continuous along the length of the multicomponent bundle and includes a blend of polyolefin and ethylene alkyl acrylate copolymer. Bonds between multi-component strands can be formed by heating. More particularly, the first polymeric component of the multicomponent bundle comprises from about 20% to about 80% by weight of the bundle and the second polymeric component of the multicomponent bundle comprises from about 80% to about 80% by weight of the bundle. About 20%. Preferably, the first polymeric component of the multicomponent bundle is present in an amount of from about 40% to about 60% by weight of the bundle, and the second polymeric component of the multicomponent bundle is present in an amount of from about 60% to about 40% by weight of the bundle. %.

As used herein, the term "strand" refers to an elongated extrudate formed by passing a polymer through a shaped orifice, such as a die. Tows include discontinuous bundles of fibers having a finite length, and continuous bundles of filaments of material. The nonwoven fabrics of the present invention may be formed from man-made multiconstituent fibers. Such man-made fibers can be carded and bonded to form nonwoven fabrics. Preferably, however, the nonwoven fabrics of the present invention are formed from continuous spunbond multicomponent filaments that are extruded, drawn and laid down on a moving forming surface.

Types of nonwoven materials that may be used include powder bonded carded webs, infrared bonded carded webs, and air bonded carded webs. The infrared and air-permeable bonded carded cover can optionally comprise a blend of different fibers, the fiber lengths in the selected fabric cover can range from about 1.0 to about 3.0 inches, and the average bulk density is from about 0.02 g/cc to About 0.12g/cc.

Other suitable absorbent materials for use in the practice of the present invention may include materials commonly referred to as superabsorbents. Superabsorbents can be in different forms including particulate and fibrous forms. Well-known superabsorbent materials include AFA 130-53C produced by Dow Chemical, and W77553 and FAV880A commercially available from the Stockhausen Company of Greensboro, North Carolina. Stockhausen's W77553 is a bulk polymerized polyacrylate with a hydrophobic surface treatment. Stockhausen's FAV880A is a highly cross-linked surface superabsorbent. AFA 130-53C is an 850 to 1400 micron suspension polymerized polyacrylate material available from Dow Chemical Company of Midland, Michigan.

Hydrogel materials, commonly referred to as superabsorbents, may be in the form of slightly crosslinked and partially neutralized hydrogel-forming polymeric components that are soluble in water. It can be prepared from unsaturated polymerizable monomers containing acid groups and a crosslinking agent. Such superabsorbents are taught in U.S. Patent 4,798,603 to Meyers et al., reissued U.S. Patent 32,649 to Brandt et al., and U.S. Patent 4,467,012 to Pedersen et al. and published European Patent Application 0,339,461 to Kellenberger . The disclosures of these patents and European patent applications are incorporated herein by reference in their entirety.

Additionally, materials known to be "slow" superabsorbents are also useful in the practice of the present invention. "Slow" superabsorbents are superabsorbents that have an Absorption Time Index (ATI) of at least 5 minutes and preferably greater than 10 minutes. Tuning the rate of absorption of superabsorbents can be achieved by varying the particle size, surface properties, and polymer chemistry. Such slow superabsorbents are described in detail in US Patent 5,843,063 to Anderson et al., the disclosure of which is incorporated herein by reference.

Suitable absorbent materials for use in the practice of the present invention may also take the form of absorbent foams such as open cell polyurethane foams as disclosed, for example, in US Patent 5,853,402 to Faulks et al., the disclosure of which is incorporated herein by reference. Furthermore, starch foams such as those disclosed in U.S. Patent 5,506,277 to Griesbach III, the disclosure of which is incorporated herein by reference, may also be used.

The present invention may also utilize corrugated nonwovens such as the high bulk corrugated nonwovens disclosed in US Patent 3,668,054 to Stumpf as suitable absorbent materials, the disclosure of which is incorporated herein by reference. As disclosed herein, such fabrics generally comprise an initially aligned corrugated covering of textile fibers embedded in a continuous film of thermoplastic adhesive of substantially constant thickness. The resulting sheathing adhesive material is then corrugated to provide a plurality of grooves and grooves that connect irregularly near its root and along its respective sides.

It will be appreciated that suitable materials for use in the practice of the present invention may be variously suitably formed, such as meltblown or airlaid or airformed. The term "meltblown fibers" generally refers to fibers formed by extruding molten thermoplastic material in the form of molten filaments or filaments through a plurality of small, usually circular die capillaries, into a converging high-velocity gas stream (such as a stream of air), The latter attenuates the filaments of molten thermoplastic material so that their diameter is reduced to that of a microfiber. The meltblown fibers are then generally entrained by a high velocity air stream and deposited onto a collecting surface, resulting in a covering consisting of a random, scattered distribution of meltblown fibers. Meltblown fibers can be continuous or discontinuous and are generally sticky when deposited onto a collecting surface. Meltblown materials are described in detail in US Patent 5,656,361 to Vogt et al., the disclosure of which is incorporated herein by reference.

Furthermore, constructions such as absorbent material comprising or including one or more different additives such as coagulants, dispersants or superabsorbents may also be used. As determined above, adjacent absorbent members preferably differ in one or more properties or characteristics, such as chemical composition or construction such as fiber orientation or thickness. According to a preferred embodiment of the present invention, such adjacent absorbent members advantageously differ in a selected property or characteristic, preferably other than density, such as is not readily available using the prior art. In particular, minimizing or eliminating horizontal dependencies between or between adjacent absorbent layers can result in the utilization of absorbent materials selected for particular or specific properties or characteristics.

Furthermore, it is understood that the broader applicability of the present invention is not necessarily limited to a particular or particular absorbent material, and that other absorbent materials, such as those known to those of ordinary skill in the art, may be used, if desired. For example, various materials are designed and modified to better handle or apply the different conditions that such products may need to apply.

In the practice of the present invention, if desired, the barrier and absorbent members may be loosely layered, or joined by the use of adhesives, thermal or ultrasonic techniques, stitching or sewing techniques, or other suitable joining techniques known in the art. onto adjacent barriers and absorbers.

It will be appreciated that the broader applications of the present invention are not necessarily limited to, for example, the use of the above-described absorbent pad assembly as the entire or substantially entire absorbent core. For example, absorbent articles according to the present invention may employ such an absorbent pad assembly as part of an absorbent core upon which other absorbent elements, including possibly other absorbent materials, are layered, folded or formed adjacent thereto. Furthermore, absorbent articles according to the present invention include a central portion formed from or comprising other absorbent elements, and the absorbent pad assembly of the present invention is layered, folded, or formed adjacent thereto.

4-6 are schematic simplified partial top views of absorbent articles 70, 72 and 74, respectively, according to alternative embodiments of the present invention.

As shown in Figure 4, the absorbent article 70 includes a backsheet 80, an absorbent core 82 and a topsheet (not shown). The absorbent core 82 includes a centrally positioned or placed absorbent pad assembly 84 similar to that described above, each having a plurality of vertically oriented absorbent members 86(a-i) sandwiched by a generally planar fluid transport barrier 88(a-h). Corresponding pairs and between other adjacent absorbent members.

The absorbent article 72 illustrated in Figure 5 includes a backsheet 90, an absorbent core 92, and a topsheet (not shown). The absorbent core 92 includes a centrally positioned or positioned absorbent pad assembly 94 similar to that described above, however, two or more absorbent members are sandwiched between at least some of the nearest adjacent barrier members.

More particularly, the absorbent pad assembly 94 includes a plurality of vertically oriented absorbent members 96(a-i) each having a generally planar fluid transport barrier 98(a-d).

Figure 6 shows an absorbent article 74 comprising a backsheet 100, an absorbent core 102 and a topsheet (not shown). The absorbent core 102 includes a centrally positioned or positioned absorbent pad assembly 104 similar to that described above comprising vertically oriented absorbent members 106(a-e) each having a generally planar fluid transport barrier 108(a-d). However, in the absorbent pad assembly 104, the one or more generally planar fluid transport barriers 108(a-d) are in intermittent form. For example, delivery barrier 108a includes a first section 110 and a second section 112 . Similarly, delivery barrier 108b includes segments 116 , 120 and 122 ; delivery barrier 108c includes segments 124 , 126 and 130 ; and delivery barrier 108d includes segments 132 and 134 .

Although the barrier sections and absorbent members of the absorbent article 74 are shown as having a uniform or symmetrical pattern, the broader scope of the present invention is not necessarily so limited. For example, either or both of the barrier section and the absorbent member may be of non-uniform or asymmetrical pattern as desired for the particular application in which the absorbent pad assembly or absorbent article is used.

Although the segments of a particular barrier are not necessarily joined together, the use of joined barrier segments generally simplifies manufacturing and assembly, which is often preferred. However, the use of sections that are not connected together may allow greater design flexibility, eg two or more different materials may be used for each section of a particular barrier.

7-9 are schematic simplified cross-sectional side views of absorbent articles 140, 142 and 144, respectively, viewed along the X-X axis according to some alternative preferred embodiments of the present invention.

Figure 7 shows an absorbent article 140 comprising the topsheet 150 and backsheet 152 and absorbent core 154 as described above. The absorbent core 154 includes an absorbent pad assembly 156 according to one embodiment of the present invention. More particularly, absorbent pad assembly 156 is generally comprised of a plurality of vertically oriented absorbent members 160(a-m) and generally planar fluid transport barriers 162(a-f), respectively.

FIG. 8 shows an absorbent article 142 comprising the topsheet 166 and backsheet 170 and absorbent core 172 described above. Absorbent core 172 comprises absorbent pad assembly 174 according to a particular embodiment of the present invention, and in the construction of a preferred embodiment of the present invention, absorbent pad assembly 174 is respectively made up of several vertically oriented absorbent members 176 (a-n) and generally planar Fluid delivery barriers 180(a-i) are formed. In these and subsequent figures, the semi-permeable or directional properties of certain such barriers are indicated briefly by the reference numerals designated herein, and differentiated here, rather than the use of cones and the like as in Figure 3 and above express.

According to this embodiment, barriers 180c and 180g are generally impermeable to fluid therethrough, barriers 180d, 180e and 180f have semi-permeable properties and thus generally do not allow at least some material to flow therethrough, barriers 180a, 180b, 180h and 180i are directional barriers, so fluid is usually best flowed through them in one specific direction. More particularly, barrier 180a generally only allows fluid to flow therethrough from absorbent member 176a to absorbent member 176b. Similarly, barriers 180b, 180h, and 180i generally only allow fluid in the direction from absorbent 176b to absorbent 176c, from absorbent 176m to absorbent 1761, and from absorbent 176n to absorbent 176m. flow in the direction.

It will be apparent to those of ordinary skill in the art that such or similar designs or configurations may be used, such as to provide absorbent pad assemblies or related absorbent pad assemblies having particular needs or sought-after absorbent properties or characteristics particularly suited for a particular application or use. absorbent articles.

Figure 9 shows an absorbent article 144 comprising the topsheet 180 and backsheet 182 and absorbent core 184 described above. Absorbent core 184 comprises absorbent pad assembly 186 according to a particular embodiment of the present invention, and in the construction of another preferred embodiment of the present invention, absorbent pad assembly 186 is respectively made up of several vertically oriented absorbent members 190 (a-n) and generally planar The fluid delivery barrier 192(a-i) constitutes.

With respect to absorbent article 30 shown in FIG. 3, in absorbent article 144, barrier members 192b, 192c, 192g, and 192h are each vertically non-coextensive with respect to adjacent absorbent members and, for example, may allow contact between selected parts of the piece.

It will be appreciated that various modifications and combinations of the above-described embodiments are possible and included herein. For example, possible variations of the various above-described embodiments involve layers comprising one or more overlying or underlying voided layers or other selected absorbent article materials. More particularly, in accordance with the present invention, it is desirable to include a layer of a fluid-retaining material such as that described above within an absorbent article underlying the absorbent pad assembly. In some applications, it may be desirable to include a layer of fluid surge material, such as is known in the art, in superimposed relationship with absorbent pad assemblies such as those described above. Also, as the case may be, this degree of overlaying or underlaying of each overlying or underlaying layer may be partial or complete as required for a particular application.

According to the present invention, the absorbent structure may conveniently be formed or manufactured by a first generally planar fluid transport barrier of pre-selected permeability, such as the aforementioned adjacently disposed, between, eg, the aforementioned selected absorbent members, such that the relative Adjacently disposed barriers and absorbers are oriented to provide or result in a structure having a desired ratio of horizontal width to vertical height. As detailed above, structures according to the present invention advantageously comprise absorbent members having a horizontal width to vertical height ratio of no more than about 10:1, preferably no more than about 5:1, more preferably about 1 : 1 or less. It will be appreciated that the shaping or fabrication of such structures may involve desirably selecting one or more of the desired variables or parameters such as those described above, including the number, size and shape and nature of either or both adjacent arrangements of barrier and absorber elements , features, and materials of construction of either or both such barriers and absorbers, such as the teachings provided herein.

It is understood that either or both of the barrier and absorber may be initially provided in different orientations, eg, subsequent reorientation may or may not be required. However, in one particular forming method according to the invention, the barrier and absorbent elements are layered horizontally and then reoriented vertically to provide the desired structure.

As noted above, if desired, adjacent barrier and absorbent members may be loosely delaminated or interconnected by the use of adhesives, thermal or ultrasonic techniques, stitching or sewing techniques, or other suitable joining techniques known in the art. combined. According to a preferred practice of the present invention, if used, such bonding is preferably performed prior to reorientation that may be required.

Furthermore, methods of forming such absorbent structures according to the present invention may include one or more cutting steps or operations. For example, adjacently disposed barrier and absorbent members may be suitably cut to provide or supply an absorbent pad assembly having a desired selected shape or form, eg, suitable for the particular use for which such absorbent pad assembly is intended. Such cutting may occur before or after orientation or both, as desired for a particular application. For example, different means are available known in the art, whereby such cutting of adjacent absorbent elements can be achieved using, for example, slit knife and water jet cutting.

Although the invention has been described above with respect to absorbent articles in which the absorbent core comprises a separate absorbent pad assembly according to the invention, it will be appreciated that the broader applicability of the invention is not limited thereto. For example, it will be understood by those of ordinary skill in the art that the present invention may employ absorbent articles comprising two or other selected plurality of such absorbent pad assemblies, if desired. Moreover, such absorbent articles may comprise two or more such absorbent pad assemblies in spaced apart, overlapping, partially overlapping or other selected relationship as desired for a particular application.

Thus, the present invention provides absorbent pad assemblies, absorbent articles and related methods which allow more complete or full utilization of their absorbent capacity as desired. For example, absorbent pad assemblies and absorbent articles may have barriers, such as those described above, positioned between selected vertical sections of a particular absorbent to regulate fluid flow therein. In particular, such absorbent pad assemblies and absorbent articles may be oriented and designed as barriers for directing fluid flow so as to allow better utilization of the absorbent capacity, for example by better or more complete utilization of the midsection and length of the corresponding absorbent article, At the same time, undesired saturation of the edges of the absorbent article with fluid is generally avoided, for example by preferentially draining or directing the flow of fluid towards the center of the absorbent structure. With this in mind, it will be appreciated that the present invention generally also provides absorbent pad assemblies, absorbent articles, and related methods that are responsive to a potentially wide range of operating and performance conditions to which such assemblies and articles are exposed in a corresponding manner. Implemented in a more effective and/or efficient manner than before.

The invention properly disclosed herein may be practiced in the absence of any element, part, step, component or ingredient not specifically disclosed herein.

Although the invention has been described in detail in some preferred embodiments, numerous details have been set forth for purposes of explanation, and it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments without exceeding the basic principles of the parts. effects, and some of the details described here may vary considerably.

Claims (58)

1, a kind of absorption pad assembly, it comprises: at least one is the first common planar FLUID TRANSPORTATION block piece of differential permeability in advance, and this FLUID TRANSPORTATION block piece is interposed between first and second vertically orientated absorbent members.

2, absorption pad assembly as claimed in claim 1 is characterized in that, at least the first block piece comprises impermeable material.

3, absorption pad assembly as claimed in claim 1 is characterized in that, at least the first block piece comprises the flowing positioning material.

4, absorption pad assembly as claimed in claim 1 is characterized in that, at least the first block piece comprises semipermeable materials.

5, absorption pad assembly as claimed in claim 1 is characterized in that, at least the first block piece is upheld with one of them vertical being total in first and second absorbing component.

6, absorption pad assembly as claimed in claim 5 is characterized in that, at least the first block piece is vertical with first and second absorbing component upholds altogether.

7, absorption pad assembly as claimed in claim 1 is characterized in that, at least the first block piece is upheld with one of them vertical non-being total in first and second absorbing component.

8, absorption pad assembly as claimed in claim 7 is characterized in that, the vertical non-extension altogether with first and second absorbing component of at least the first block piece.

9, absorption pad assembly as claimed in claim 1 is characterized in that, at least the first block piece is a form of discontinuity.

10, absorption pad assembly as claimed in claim 1 is characterized in that, each forms first and second absorbing component by having different absorbefacient materials.

11, absorption pad assembly as claimed in claim 1 is characterized in that, each forms first and second absorbing component by the material with same absorbent.

12, absorption pad assembly as claimed in claim 1 is characterized in that, it also comprises second block piece that separates at least the second absorbing component with at least the first block piece.

13, absorption pad assembly as claimed in claim 12 is characterized in that, second excludes second absorbing component at least one absorbing component of also being separated by outward mutually with at least the first block piece.

14, absorption pad assembly as claimed in claim 1 is characterized in that, one of them first and second absorbing component comprises the material of surging.

15, absorption pad assembly as claimed in claim 1 is characterized in that, at least one in first and second absorbing component comprises the superabsorbent thing.

16, absorption pad assembly as claimed in claim 1 is characterized in that, at least one in first and second absorbing component comprises the non-woven material of being made by the air shaping matrix of thermoplastic polymer fiber and the multiple wood pulp cellulose of handling respectively.

17, absorption pad assembly as claimed in claim 1, it is characterized in that, in first and second absorbing component at least one comprises the multicomponent polymerization bundle that extrudes that contains the first and second polymerization compositions, this first and second aggregates into branch and is arranged in different basically zone on the cross section of multicomponent bundle, and extends continuously along the length of multicomponent bundle.

18, a kind of absorbent article, it has a contact surface, this absorbent article comprises: an absorption pad assembly, this absorption pad assembly comprises at least the first and second common planar FLUID TRANSPORTATION block pieces, each block piece has the permeability of selecting in advance, and be interposed between a pair of absorbing component, this absorbing component vertically is provided with respect to contact surface usually.

19, absorbent article as claimed in claim 18 is characterized in that, first and second block pieces have the identical permeability of selecting in advance.

20, absorbent article as claimed in claim 18 is characterized in that, first and second block pieces have the different permeabilitys of selecting in advance.

21, absorbent article as claimed in claim 18 is characterized in that, at least one in first and second block pieces comprises impermeable material.

22, absorbent article as claimed in claim 18 is characterized in that, at least one in first and second block pieces comprises the flowing positioning material.

23, absorbent article as claimed in claim 18 is characterized in that, at least one in first and second block pieces comprises semipermeable materials.

24, absorbent article as claimed in claim 18 is characterized in that, the spaced apart some absorbing components of first and second block pieces.

25, absorbent article as claimed in claim 18 is characterized in that, it also is included in the liquid-tight tergite on the garment side of goods.

26, absorbent article as claimed in claim 18 is characterized in that, it also is included in the saturating liquid overlay on the body side surface of goods.

27, absorbent article as claimed in claim 18 is characterized in that, it is a sanitary towel.

28, a kind of method, it comprises:

At adjacent at least one first common planar FLUID TRANSPORTATION block piece of differential permeability in advance that is provided with between first and second absorbing component at least, and make the block piece of adjacent setting and first and second absorbing component orientation, wherein each first and second absorbing component has the ratio that is no more than about 10: 1 horizontal width and vertical height.

29, method as claimed in claim 28 is characterized in that, each all has the ratio that is no more than about 1: 1 horizontal width and vertical height first and second absorbing component of directed adjacent setting.

30, method as claimed in claim 28 is characterized in that, it also comprises:

Cut first block piece and first and second absorbing component of adjacent setting, to form the absorption pad assembly.

31, method as claimed in claim 30 is characterized in that, first block piece of adjacent setting and first and second absorbing component were cut before orientation.

32, method as claimed in claim 30 is characterized in that, first block piece of adjacent setting and first and second absorbing component are cut after orientation.

33, method as claimed in claim 30 is characterized in that, cutting step comprises the cutting of slit cutter.

34, method as claimed in claim 30 is characterized in that, cutting step comprises the water jet cutting.

35, method as claimed in claim 28 is characterized in that, it also is included in directed first block piece of adjacent setting and at least one mutual step for adhering in first and second absorbing component of making before.

36, method as claimed in claim 35 is characterized in that, adhesion step comprises that binding agent is bonding.

37, method as claimed in claim 35 is characterized in that, adhesion step comprises heat bonding.

38, method as claimed in claim 35 is characterized in that, adhesion step comprises ultrasonic bonds.

39, method as claimed in claim 35 is characterized in that, each of first block piece and first and second absorbing component is bonding before orientation.

40, method as claimed in claim 28 is characterized in that, first block piece comprises impermeable material.

41, method as claimed in claim 28 is characterized in that, first block piece comprises the flowing positioning material.

42, method as claimed in claim 28 is characterized in that, first block piece comprises semipermeable materials.

43, method as claimed in claim 28 is characterized in that, first block piece is upheld with at least one vertical being total in first and second absorbing component.

44, method as claimed in claim 43 is characterized in that, first block piece is vertical with first and second absorbing component upholds altogether.

45, method as claimed in claim 28 is characterized in that, first block piece is upheld with at least one vertical non-being total in first and second absorbing component.

46, method as claimed in claim 45 is characterized in that, the vertical non-extension altogether with first and second absorbing component of first block piece.

47, method as claimed in claim 28 is characterized in that, first block piece is a form of discontinuity.

48, method as claimed in claim 28 is characterized in that, each forms first and second absorbing component by having different absorbefacient materials.

49, method as claimed in claim 28 is characterized in that, each forms first and second absorbing component by the material with same absorbent.

50, method as claimed in claim 28 is characterized in that, also comprises second block piece with spaced apart at least the second absorbing component of at least the first block piece.

51, method as claimed in claim 50 is characterized in that, first and second block pieces spaced apart except that second absorbing component also spaced apart at least one absorbing component.

52, a kind of method that forms the absorption pad assembly, described method comprises:

Make at least one the first common planar FLUID TRANSPORTATION block piece horizontal slice of differential permeability in advance between first and second absorbing component; With

Make the block piece of horizontal slice vertical with first and second absorbing component directed again.

53, method as claimed in claim 52 is characterized in that, it also comprises:

Cutting horizontal stratified first is carried block piece and first and second absorbing component.

54, method as claimed in claim 52 is characterized in that, its also be included in vertical make before directed again first of horizontal slice carry block piece respectively with first and second absorbing component step for adhering.

55, method as claimed in claim 52 is characterized in that, each all has the width that is no more than about 20mm vertical first and second directed again absorbing component.

56, method as claimed in claim 52 is characterized in that, each all has the ratio of width to height less than 1 vertical directed again first and second absorbing component.

57, a kind of method that is used to improve fluid treatment by absorbent article, this absorbent article has a contact surface, and this absorbent article comprises a saturating liquid overlay, a liquid-tight tergite, and be arranged on an absorption pad assembly between overlay and the tergite, this method comprises:

Utilize a kind of absorption pad assembly, this absorption pad assembly comprises first a common planar FLUID TRANSPORTATION block piece of differential permeability in advance, and this FLUID TRANSPORTATION block piece is interposed in a pair of usually with respect between the vertically disposed absorbing component of contact surface.

58, method as claimed in claim 57 is characterized in that, absorbent article is a sanitary towel.

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