Patent Application
20220287891
Infants and other incontinent individuals wear disposable absorbent articles such as diapers to receive and contain urine and other body exudates. In order to contain body exudates as well as to fit a wide variety of body shapes and sizes, these pants must fit snugly about the waist and legs of the wearer without drooping, sagging or sliding down from its position on the torso as well as fitting larger wearers without causing irritation to the skin due to the product being too tight. Thus, the pant must have elastic extensibility in the waist and legs with the elastic features providing a high degree of stretch.
Many absorbent articles such as diapers, training pants, incontinence products, other personal care or health care garments or the like use conventional elastic elements secured in an elastically contractible condition in the waist and leg openings. Typically, in order to insure full elastic fit about the leg and the waist such as is provided with durable undergarments, the leg openings and waist opening are encircled with elasticized bands of rubber or other materials positioned along the curve of the opening. These pants are typically characterized as “balloon style” pants because of the contraction caused by the elasticized bands in specific zones of the product while the remaining material tends to blouse. Examples of such training pants are disclosed in U.S. Pat. No. 5,171,239 to lgaue, et al. on Dec. 15, 1992 and U.S. Pat. No. 4,610,681 to Strohbeen, et al. on Sep. 9, 1986. Although these pants will allow fit of various waist and leg sizes due to the fact that the contractive elastic openings will expand to accommodate various size wearers, these products still fit a limited range of fit sizes because the elastic elements are in contraction and do not have a high degree of stretch. The narrow elastic bands used in the waist opening and the leg openings also tend to concentrate the “fitment” forces in a narrow zone of the wearer's body leading to increased incidence of skin marking of the wearer. Further, the sides and remainder of the products are typically not elastically extensible thereby reducing the fit.
In order to solve this deficiency in balloon-style pants, some manufacturers have positioned elastic strands across the entire front and back regions of the product. For example, WO 93/17648 published on Sep. 16, 1993, discloses a pant-type diaper in which the front and/or the rear pans are elastically contractible and the ends of the absorbent core are disposed in these regions. These additional elastic strands act to contract the entire front and back waist parts of the pant including the end areas of the absorbent core. This allows greater expansion of the product in the waist region but causes the absorbent core to be gathered and bunch at the waist opening. This gathering and bunching results in a higher risk of leakage at the waist since channels are created along the absorbent core that allows body exudates to wick or flow out of the waist. This gathering of the absorbent core also affects the appearance of the product in that the product does not appear as aesthetically pleasing as the balloon style pants.
Another type training pant is shown in U.S. Pat. No. 4,940,464 issued to Van Gompel, et al. on Jul. 10, 1990, wherein a pant-like garment is formed by attaching discrete stretchable members to the side edges of the main body of the garment. This stretchable member allows the article to fit variations in size as the stretchable member expands to meet the size of the wearer. However, the seaming of the main body with the stretchable members are a major problem in the product and in the manufacturing process. The seams must be made extremely strong and capable of handling great forces during application and use. A pant undergoes severe forces and stresses during use which may cause the side panels to break away or tear from the main body portion. Further, controlling these separate stretchable members severely complicates the manufacturing process and causes these pants to be more costly to the consumer. The seams to the main body portion also tend to concentrate the fitment forces at the top and bottom of the product resulting in increased seam tearing and poorer fit of the garment.
U.S. Pat. No. 5,246,433 issued to Hasse, Bridges and Miller on Sep. 21, 1993, discloses a pant having stretch laminate side panels as well as elastic waistbands and leg bands. The stretch laminates in the side panels provide stretch in the sides of the product to better fit the pant on the wearer. The stretch laminates are unitary with the rest of the pant to overcome the drawbacks associated with the pants having separate and discrete elastic panel members attached thereto while improving the fit over the conventional balloon-style pants. However, these pants suffer from the drawback that the side panels are not sufficiently stretchable to allow a wearer to easily pull the pant on by themselves. The stretch laminates disclosed therein provide a limited amount of stretch. Further, the materials used to form the stretch laminates can have problems with tearing or shredding during use resulting in the products being scrapped by the manufacturer.
Another drawback with all of these products is the breathability of the product. The panels of the pant are typically formed by films or forms which can preclude the breathability of such products. This lack of breathability may result in a hot stuffy product for the wearer.
It is, therefore, desirable to provide a disposable absorbent article with a high degree of breathability at the side panels to allow vapor transmission so that the absorbent article is not hot and stuffy. Additionally it is desirable to provide a disposable absorbent article such that it will have improved stretchability and fit at the side panels so as to reduce waist and leg load tensions for the wearer.
In response to the above-referenced unfulfilled need in the art, a new disposable absorbent article having a plurality of slits positioned in a middle region below the top and above bottom edges of side panels of the absorbent article has been discovered. By placing the plurality of slits below the top and above the bottom edges of the side panels improves absorbent article breathability and lessens the amount of force the absorbent article applies onto the wearer's leg when donned.
In one embodiment, the present invention pertains to an absorbent article including an absorbent chassis defining: a longitudinal axis, a transverse axis, front and back waist edges parallel to the transverse axis, opposite side edges extending between the front and back waist edges, a front waist region contiguous with the front waist edge, a back waist region contiguous with the back waist edge, and a crotch region which extends between and interconnects the front and back waist regions, the front waist region defining a pair of transversely opposed front side panels having an upper edge contiguous with the front waist edge and a bottom edge and a front center panel positioned between and interconnecting the front side panels, the back waist region defining a pair of transversely opposed back side panels having an upper edge contiguous with the back waist edge and a bottom edge and a back center panel positioned between and interconnecting the back side panels, wherein the front and back side panels have a length extending from the upper edge to the lower edge, an upper portion adjacent to the upper edge and having an upper portion length, a lower portion adjacent to the bottom edge and having a lower portion length, and a middle portion disposed between the upper and lower portions and having a middle portion length a plurality of slits disposed within the middle portion and wherein the upper and lower portions are substantially free from slits.
In a further embodiment of the present invention, an absorbent article comprises: a chassis having a longitudinal axis, a transverse axis, a front waist portion having a front waist edge and a back waist portion having a back waist edge; a pair of elastomeric front side panels that are extensible in the transverse direction, the front side panels extending from the front waist portion and having an upper edge portion that is contiguous with the front waist edge, and a lower edge portion, an outer most surface and opposed inner most surface, each front side panel having a length extending from the upper edge to the lower edge, an upper portion adjacent to the upper edge and having an upper portion length, a lower portion adjacent to the bottom edge and having a lower portion length, and a middle portion disposed between the upper and lower portions and having a middle portion length, wherein the middle portion comprises a plurality of longitudinally orientated slits extending from the outer most surface to the inner most surface and having a first aspect ratio and the upper and lower portions are substantially free from slits; and a pair of elastomeric back side panels that are extensible in the transverse direction, the front side panels extending from the back waist portion and having an upper edge portion that is contiguous with the back waist edge, and a lower edge portion, an outer most surface and opposed inner most surface, each back side panel having a length extending from the upper edge to the lower edge, an upper portion adjacent to the upper edge and having an upper portion length, a lower portion adjacent to the bottom edge and having a lower portion length, and a middle portion disposed between the upper and lower portions and having a middle portion length, wherein the middle portion comprises a plurality of longitudinally orientated slits extending from the outer most surface to the inner most surface and having a first aspect ratio and the upper and lower portions are substantially free from slits, wherein upon donning of the article by a wearer the first aspect ratio is decreased.
In yet a further embodiment of the present invention discloses a side panel for joining the front waist region and rear waist region of an absorbent article chassis having a longitudinal axis and a transverse axis, the side panel comprising: an elastic laminate extensible in the transverse direction and comprising two layers of nonwoven on either side of an elastic film, the laminate having first and second opposed outer surfaces; an upper edge; a lower edge; a length extending from the upper edge to the lower edge; an upper portion adjacent to the upper edge and having an upper portion length and being substantially free from apertures, a lower portion adjacent to the bottom edge and having a lower portion length and being substantially free from apertures, and a middle portion disposed between the upper and lower portions and having a middle portion length and having a plurality of longitudinally orientated slits extending from the first to the second outer surfaces and having a first aspect ratio.
The disclosure may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawing, in which:
While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawing and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
When introducing elements of the present disclosure or the preferred embodiment(s) thereof, the articles “a”, “an”, and “the” are intended to mean that there are one or more of the elements.
The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
The term “absorbent article” refers to devices that absorb and contain body exudates, and, more specifically, refers to devices that are placed against or in proximity to the body of the wearer to absorb and contain the various exudates discharged from the body. Absorbent articles may include diapers, pant diapers, open diapers, diaper covers having fastening means for fastening the diaper, training pants, adult incontinence undergarments, feminine hygiene products, breast pads, care mats, bibs, wound dressing products, and the like. As used herein, the term “body exudates” includes, but is not limited to, urine, blood, vaginal discharges, breast milk, sweat and fecal matter.
The term “longitudinal” and “transverse” have their customary meaning, as indicated by the longitudinal and transverse axes depicted in
The term “tension” includes a uniaxial force tending to cause the extension of a body or the balancing force within that body resisting the extension.
The term a “layer” or “web” as used herein is a generally two-dimensional structure that may comprise one or more plies and may be in the form of a laminate made from plies of the same or different materials.
The term “aspect ratio” when referring to the dimensions of an aperture, such as a slit or a hole, is the ratio of the lengths of the major and minor axis. For example, with reference to
The term “aperture” refers to gap, hole, orifice or other opening extending form a first surface to a second surface.
The term “slit” refers to an aperture having an aspect ratio greater than about 3, such as greater than 5, such as greater than 10. In certain embodiments, slits may be selectively disposed in the middle portion of a side panel and form a continuous passage from the a first outer surface of the panel to a second outer surface and may have a relatively high aspect ratio, such as greater than about 3, such as greater than 5, such as greater than 10 and a small open area when the side panel is in an untensioned state.
The term “hole” refers to an aperture having an aspect ratio less than 3, such as less than 2. In certain embodiments, holes may be selectively disposed in the middle portion a side panel and form a continuous passage from the a first outer surface of the panel to a second outer surface and may have an aspect ratio less than 3, such as less than 2, such as from about 0.5 to about 1.5 and have an open area from about 2 mm to about 5 mm and from about 3 mm to about 5 mm when in a tensioned state. The dimensions or a hole are generally measured when the article or side panel is tensioned, such as an extension force of about 700 gf.
As used herein, the term “extensible” refers to any material which, upon application of a biasing force, is elongatable by at least about 10 percent, at least about 20, or at least about percent 50 percent, without experiencing catastrophic failure. Recovery of the strain is not required for a material to be considered extensible.
With reference to
The illustrated absorbent chassis 32 comprises a rectangular composite structure 33, a pair of transversely opposed front side panels 34, and a pair of transversely opposed back side panels 134. The composite structure 33 and side panels 34 and 134 may be integrally formed or comprise two or more separate elements, as shown in
The front and back waist regions 22 and 24 of the diaper pant 20 are joined together to define a three-dimensional pant configuration having a waist opening 50 and a pair of leg openings 52 (
The front waist region 22 of the absorbent chassis 32 includes the transversely opposed front side panels 34 and a front center panel 35 (
The absorbent chassis 32 is configured to contain and/or absorb any body exudates discharged from the wearer. For example, the absorbent chassis 32 may, although not necessarily, comprise the pair of containment flaps 46 which are configured to provide a barrier to the transverse flow of body exudates. A flap elastic member 53 (
To further enhance containment and/or absorption of body exudates, the training pant 20 desirably includes a front waist elastic member 54, a rear waist elastic member 56, and leg elastic members 58, as are known to those skilled in the art (
The flap elastic members 53, the waist elastic members 54 and 56, and the leg elastic members 58 (
The outer cover 40 desirably comprises a material that is substantially liquid impermeable, and can be elastic, stretchable or nonstretchable. The outer cover 40 may be a single layer of liquid impermeable material, but desirably comprises a multi-layered laminate structure in which at least one of the layers is liquid impermeable. For instance, the outer cover 40 may include a liquid permeable outer layer and a liquid impermeable inner layer that are suitably joined together by a laminate adhesive (not shown). Suitable laminate adhesives, which may be applied continuously or intermittently as beads, a spray, parallel swirls, or the like, can be obtained from Findley Adhesives, Inc., of Wauwatosa, Wis., U.S.A., or from National Starch and Chemical Company, Bridgewater, N.J., U.S.A. The liquid permeable outer layer can be any suitable material and desirably one that provides a generally cloth-like texture. One example of such a material is a 20 gsm (grams per square meter) spunbond polypropylene nonwoven web. The outer layer may also be made of those materials of which liquid permeable bodyside liner 42 is made. While it is not a necessity for outer layer to be liquid permeable, it is desired that it provides a relatively cloth-like texture to the wearer.
The inner layer of the outer cover 40 may be both liquid and vapor impermeable, or can be liquid impermeable and vapor permeable. The inner layer is desirably manufactured from a thin plastic film, although other flexible liquid impermeable materials may also be used. The inner layer, or the liquid impermeable outer cover 40 when a single layer, prevents waste material from wetting articles, such as bedsheets and clothing, as well as the wearer and caregiver. A suitable liquid impermeable film for use as a liquid impermeable inner layer, or a single layer liquid impermeable outer cover 40, is a 1.0 mil polyethylene film commercially available from Edison Plastics Company of South Plainfield, N.J., U.S.A. If the outer cover 40 is a single layer of material, it can be embossed and/or matte finished to provide a more cloth-like appearance. As earlier mentioned, the liquid impermeable material can permit vapors to escape from the interior of the disposable absorbent article, while still preventing liquids from passing through the outer cover 40. A suitable “breathable” material is composed of a microporous polymer film or a nonwoven fabric that has been coated or otherwise treated to impart a desired level of liquid impermeability. A suitable microporous film is a PMP-1 film material commercially available from Mitsui Toatsu Chemicals, Inc., Tokyo, Japan, or an XKO-8044 polyolefin film commercially available from 3M Company, Minneapolis, Minn., U.S.A.
As shown in
The liquid permeable bodyside liner 42 is illustrated as overlying the outer cover 40 and may but need not have the same dimensions as the outer cover 40. The bodyside liner 42 is desirably compliant, soft feeling, and non-irritating to the child's skin.
The bodyside liner 42 may be manufactured from a wide selection of web materials, such as synthetic fibers (for example, polyester or polypropylene fibers), natural fibers (for example, wood or cotton fibers), a combination of natural and synthetic fibers, porous foams, reticulated foams, apertured plastic films, or the like. Various woven and nonwoven fabrics may be used for the bodyside liner 42. For example, the bodyside liner may be composed of a meltblown or spunbonded web of polyolefin fibers. The bodyside liner may also be a bonded-carded web composed of natural and/or synthetic fibers. The bodyside liner may be composed of a substantially hydrophobic material, and the hydrophobic material can, optionally, be treated with a surfactant or otherwise processed to impart a desired level of wettability and hydrophilicity. For example, the material can be surface treated with about 0.28 weight percent of a surfactant commercially available from the Rohm and Haas Co. under the trade designation Triton X-102. The surfactant can be applied by any conventional means, such as spraying, printing, brush coating or the like. The surfactant can be applied to the entire bodyside liner 42 or can be selectively applied to particular sections of the bodyside liner, such as the medial section along the longitudinal centerline.
A suitable liquid permeable bodyside liner 42 is a nonwoven bicomponent web having a basis weight of about 27 gsm. The nonwoven bicomponent can be a spunbond bicomponent web, or a bonded carded bicomponent web. Suitable bicomponent staple fibers include a polyethylene/polypropylene bicomponent fiber available from CHISSO Corporation, Osaka, Japan. In this particular bicomponent fiber, the polypropylene forms the core and the polyethylene forms the sheath of the fiber. Other fiber orientations are possible, such as multi-lobe, side-by-side, end-to-end, or the like. While the outer cover 40 and bodyside liner 42 can comprise elastomeric materials, it can be desirable in some embodiments for the composite structure to be generally inelastic, where the outer cover, the bodyside liner and the absorbent assembly comprise materials that are generally not elastomeric.
The absorbent assembly 44 (
Suitable 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. Suitable superabsorbent materials are available from various commercial vendors, such as Dow Chemical Company located in Midland, Mich., U.S.A., and Stockhausen GmbH and Co. KG, D-47805 Krefeld, Federal Republic of Germany. Typically, a superabsorbent material is capable of absorbing at least about 15 times its weight in water, and desirably is capable of absorbing more than about 25 times its weight in water.
In one embodiment, the absorbent assembly 44 is generally rectangular in shape, and comprises a blend of wood pulp fluff and superabsorbent material. One preferred type of fluff is identified with the trade designation CR1654, available from Kimberly-Clark Corporation, Neenah, Wis., U.S.A., and is a bleached, highly absorbent sulfate wood pulp containing primarily soft wood fibers. As a general rule, the superabsorbent material is present in the absorbent assembly 44 in an amount of from about 5 to about 90 weight percent based on total weight of the absorbent assembly. The absorbent assembly 44 suitably has a density within the range of about 0.10 to about 0.35 grams per cubic centimeter. The absorbent assembly 44 may or may not be wrapped or encompassed by a suitable tissue wrap that maintains the integrity and/or shape of absorbent assembly.
The absorbent chassis 32 may also incorporate other materials that are designed primarily to receive, temporarily store, and/or transport liquid along the mutually facing surface with absorbent assembly 44, thereby maximizing the absorbent capacity of absorbent assembly. One suitable material is referred to as a surge layer (not shown) and comprises a material having a basis weight of about 50 grams per square meter, and comprising a through-air-bonded-carded web of a homogenous blend of 60 percent 3 denier bicomponent fiber comprising a polyester core/polyethylene sheath, commercially available from BASF Corporation, and 40 percent 6 denier polyester fiber, commercially available from Hoechst Celanese Corporation, in Portsmouth, Va., U.S.A.
As noted previously, the illustrated diaper pant 20 has front and back side panels 34 and 134 disposed on each side of the absorbent chassis 32. These transversely opposed front side panels 34 and transversely opposed back side panels 134 can be permanently bonded to the composite structure 33 of the absorbent chassis 32 in the respective front and back waist regions 22 and 24, and are releasably attached to one another by the fastening system 80. More particularly, as shown best in
The illustrated side panels 34 and 134 each define a distal edge 68 that is spaced from the attachment line 66, a waist end edge 72 disposed toward the longitudinal center of the training pant 20, and a waist end edge 72 disposed toward a longitudinal end of the training pant. The waist end edge 72 extend from the side edges 47 of the composite structure 33 to the distal edges 68. The waist end edges 72 of the side panels 34 and 134 form part of the side edges 36 of the absorbent chassis 32. In the back waist region 24, the waist end edges 72 are desirably although not necessarily angled relative to the transverse axis 49 to provide greater coverage toward the back of the pant as compared to the front of the pant. The waist end edges 72 are desirably parallel to the transverse axis 49. The waist end edges 72 of the front side panels 34 form part of the front waist edge 38 of the absorbent chassis 32, and the waist end edges 72 of the back side panels 134 form part of the back waist edge 39 of the absorbent chassis.
The side panels 34 and 134 desirably have a length dimension (L1) measured parallel to the longitudinal axis 48 from the front upper edge 60 to the front bottom edge 62. The length dimension L1 may vary, however, in certain preferred embodiments L1 is at least about 20 percent, such as at least about 25 percent, such as about 30 percent or greater, of the overall length dimension of the absorbent article, also measured parallel to the longitudinal axis 48.
As shown in
The side panels are generally rectilinear in shape, however, they may assume any number of different shapes and the shape of the panels may differ from one another. For example, the shape of the first and second back side panel may differ from the shape of the first and second front side panel, such as in the embodiments illustrated in
Each of the side panels 34 and 134 may include one or more individual, distinct pieces of material. In particular embodiments, for example, each side panel 34 and 134 may include first and second side panel portions that are joined at a seam, with at least one of the portions comprising an elastomeric material. Still alternatively, each individual side panel 34 and 134 may include a single piece of material which is folded over upon itself along an intermediate fold line (not shown).
The side panels 34 and 134 desirably comprise an elastic material capable of stretching in a direction generally parallel to the transverse axis 49 of the diaper pant 20. In particular embodiments, the front and back side panels 34 and 134 may each comprise an interior portion 78 disposed between the distal edge 68 and the respective front or back center panel 35 or 135. In the illustrated embodiment, the interior portions 78 are disposed between the distal edges 68 and the side edges 47 of the rectangular composite structure 33. See
Suitable elastic materials, as well as one described process of incorporating elastic side panels into a training pant, are described in the following U.S. Patents: U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompel et al.; U.S. Pat. No. 5,224,405 issued Jul. 6, 1993 to Pohjola; U.S. Pat. No. 5,104,116 issued Apr. 14, 1992 to Pohjola; and U.S. Pat. No. 5,046,272 issued Sep. 10, 1991 to Vogt et al.; all of which are incorporated herein by reference. In particular embodiments, the elastic material comprises a stretch-thermal laminate (STL), a neck-bonded laminate (NBL), a reversibly necked laminate, or a stretch-bonded laminate (SBL) material. Methods of making such materials are well known to those skilled in the art and described in U.S. Pat. No. 4,663,220 issued May 5, 1987 to Wisneski et al.; U.S. Pat. No. 5,226,992 issued Jul. 13, 1993 to Mormon; and European Patent Application No. EP 0 217 032 published on Apr. 8, 1987 in the names of Taylor et al.; all of which are incorporated herein by reference. Alternatively, the side panel material may comprise other woven or nonwoven materials, such as those described above as being suitable for the outer cover 40 or bodyside liner 42, or stretchable but inelastic materials.
In a particularly preferred embodiment the side panels comprise of a material that is essentially two facing materials bonded to an elastic film material disposed between them. The elastic material is stretched to a percent elongation prior to the bonding with the facing materials, and then allowed to relax. The following patents describe how the strands are orientated in these elastic materials: U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompel et al.; U.S. Pat. No. 5,224,405 issued Jul. 6, 1993 to Pohjola; U.S. Pat. No. 5,104,116 issued Apr. 14, 1992 to Pohjola; and U.S. Pat. No. 5,046,272 issued Sep. 10, 1991 to Vogt et al.; all of which are incorporated herein by reference.
The diaper pant 20 according to the present invention may also include hook type fasteners which typically comprise a fabric or material having a base or backing structure and a plurality of hook members extending upwardly from at least one surface of the backing structure. In contrast to the loop type fasteners which desirably comprise a flexible fabric, the hook material advantageously comprises a resilient material to minimize unintentional disengagement of the fastener components as a result of the hook material becoming deformed and catching on clothing or other items. The term “resilient” as used herein refers to an interlocking material having a predetermined shape and the property of the interlocking material to resume the predetermined shape after being engaged and disengaged from a mating, complementary interlocking material. Suitable hook material can be molded or extruded of nylon, polypropylene or another suitable material. Suitable single-sided hook materials for the fastening components 82 and 83 or the mating fastening components 84 and 85 (
With continued reference to
The middle portion 110, is generally bounded by upper and lower portions 90, 100. The upper portion 90 is generally disposed along the upper most portion of the panel 34, 134 with its upper most edge forming the waist end edge 72. The upper portion 90 is generally substantially free from apertures and has an upper portion length (L2), which is the longitudinal distance between the back bottom edge 72 and upper boundary (b) of the middle portion. The lower portion 100, lies beneath the middle portion 110 and generally extends from the lower boundary 100 and the back bottom edge 72. The lower portion 100 has a lower portion length (L3), which is the longitudinal distance between the back bottom edge 72 and the lower boundary (d) of the middle portion.
In those instances where the side panels, such as the back side panels 134 illustrated in
The relative lengths of L2, L3 and L4 may vary, however, in certain embodiments L4 is greater than L3, which is greater than L2. In particularly preferred embodiments L2 may range from about 25 mm to about 50 mm, such as from about 35 mm to about 45 mm and L3 may range from about 10 mm to about 25 mm, such as from about 13 mm to about 17 mm. In other embodiments, L4 may range from about from about 69 mm to about 29 mm, such as from about 47 mm to about 51 mm. Additionally, L4 is from about 28% to about 66% of L1.
Regardless of the relative lengths of L2, L3 and L4, it is generally preferred that the side panels comprise a plurality of apertures and that the apertures selectively disposed on the middle portion. The number, size and spacing of the apertures may vary depending on the desired properties of the side panel, such as optimal retention (or sustained) force at the side area of the wearer or air permeability, however, it is generally preferred that the apertures by spaced away from the waist or leg end edges. In certain embodiments the number of apertures disposed on the middle portion may range from about 69 mm to about 28 mm, such as from about 47 mm to about 51 mm such as form about 48 mm to about 50 mm. In certain embodiments, the area of the middle portion may range from about 49 mm to about 50 mm and the number of apertures per middle portion unit area may range from about 4 to about 15 slits/cm2, such as from about 4 to about 10 slits/cm2, such as from about 4 to about 8 slits/cm2.
Just as the number of apertures disposed on the middle portion of the side panel may vary, the size and shape of the apertures may also vary. For example, as illustrated in
The slits may be made by any number of well-known methods for forming an aperture in a web such as, for example, ultrasonic or thermal/pressure techniques. Such slits and forming techniques are described in U.S. Pat. No. 2,544,069 issued to Cutler on Mar. 6, 1951; and U.S. Pat. No. 4,834,738 issued to Kielpikowski et al. on May 30, 1989; each of which is incorporated herein by reference. Preferably, the slits extend through all of the layers of the stretch laminates in the side panels, such that the slits extend from the inside to the outside of the product.
Generally the slits 120 (
Several slit and hole shapes useful in the present invention are illustrated in
In the embodiment illustrated in
In the embodiment illustrated in
When in the strained donned state the plurality of holes 120a in the front and back side panels may be parallel, perpendicular, or randomized with each individually. The holes 120a may comprise of an ordered or randomed pattern. In those instances where the holes are arranged in a non-random pattern, the pattern may include simple geometric patterns such as circles or diamonds, but also including complex patterns such as logos and trademarks.
Another factor which may affect the percentage open area, and thus, breathability of the web 280 of the present invention is the pattern of the primary apertures 271. Specifically, the pattern can influence the resultant open area as a function of a percentage strain. Thus, a certain pattern of apertures such as the staggered pattern of apertures 271 shown in
While the patterns illustrated in
Regardless of the particularly pattern or size and shape of apertures, the side panels of the present invention have improved air permeability over side panels of the prior art. Generally, the apertures on the front and back side panels permit the passage of air and water vapor to and from the interior of the diaper pant. In this configuration, exudates are prevented from leaking out of the areas adjacent the absorbent core but air and water vapor are allowed to be exchanged in the product to ventilate it so that the product does not become excessively wetted by body perspiration and uncomfortable to wear. As shown in the table below, diaper pants according to the present invention generally have improved air permeability in both a tensioned and untensioned state.
Accordingly, the present invention provides a side panel having an air permeability of at least about 67 cfm, such as at least about 83.8 cfm, such as at least about 89 cfm, such as from about 67 to about 89 cfm when in an untensioned state. Further, because the invention provides apertures that change in shape and area when tensioned, the side panels of the present invention have increased air permeability when in a tensioned state. For example, the side panels may have a tensioned air permeability of at least about 312 cfm, such as at least about 370 cfm, such as at least about 388 cfm, such as from about 312 to about 388 cfm. In other instances the panels may have a tensioned air permeability that is at least about 80% greater, such as at least about 80% greater than the untentionsed air permeability.
In other instances the aperture side panels of the present invention provide the benefit of reducing wearer leg load. The side panel preferably has peak load of at least 600 gf. A side panel having a peak load ranging from about 600 gf to about 700 gf, provides a garment that is easily donned by a wearer, yet provides a suitable level of body fitting/conformity. Further, a side panel having a peak load ranging from about 600 gf to about 700 gf tends not to cause red marking on the skin of the wearer and generally does not cause discomfort for the wearer during usage. Thus, the side panels of the present invention may be incorporated into absorbent articles, particularly diapers and the like, that provide enough elastic force to keep the article in place on the wearer and provide good body fit.
Air permeability was tested with a known FX3300 instrument. The Air Permeability FX3300 Tester is used for fast, simple, and accurate determination of the air permeability of non-wovens and forming fabrics. Air permeability measured in CFM or l/dm2.min, is determined by applying a very small pressure difference (of about 0.018-0.029 PSI or 1.27-2 mbar) between the two sides of a fabric and then measuring how much air flows through the fabric. For example, in the case of a very fine, dense fabric less air will pass through and thus it will have a lower CFM value.
1. An absorbent article (20), comprising:
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2019/025068 | 3/30/2019 | WO |
