Patent Application
20210128369
The present disclosure relates to disposable absorbent articles having a waist gasketing element, and more specifically to waist gasketing elements having an adhesive free-zone and an adhesive zone.
Various types of articles, such as for example, diapers and other absorbent articles, have components that include elastic parts, such as for example, waistbands. In some configurations, waistbands may be provided as a single layer of elastic material, such as an elastic film. In some configurations, the waistbands may be provided as an elastic laminate that may include elastic material bonded to one or more substrates such as nonwovens, wherein the elastic material may include an elastic film and/or elastic strands. Providing an elasticated waistband at the top edge of the disposable absorbent article can have improved fit and containment. An elasticated waistband can help contain exudates by providing increased pressure between the skin and the article to form a seal that helps to prevent exudates from exiting the product in the waist area. Additionally, elasticated waistbands can physically close gaps that may otherwise be formed when the wearer moves into positions, such as bending forward at the waist.
Waistbands can be located at one or both of the front and back edges of absorbent articles, and in closed form “pant” articles, they can be continuously formed to provide a waistband around the entire top edge of the article. In some articles, a waistband can be provided on the back only and spaced down from the edge of the article to close gaps in the rear part of the article. Articles providing a waistband that is spaced down from the edge typically exhibit larger ruffles at the top edge of the product as compared to articles having a waistband that is coterminous with the edge of the article. These ruffles can appear to caregivers as gaps from which exudates could leak even though the waist may close the gaps just below this region. Therefore, articles with waistbands that are coterminous with the edge of the article are may be preferred. However, some caregivers perceive waistbands that are spaced down from the edge of the article as being better leakage barriers.
Elasticated waistbands can comprise a variety of elastic materials such as stranded elastics, films, elastic nonwovens materials, elastic glues, and so forth. These materials can have a high coefficient of friction and/or can be tacky. Such elastic portions of the materials can be laminated to another material with a lower coefficient of friction, such as a polypropylene nonwoven, to protect the wearer from direct contact with the elastic material. The materials can be laminated together with a variety of means, including adhesively bonding, mechanically bonding, thermally bonding, or other suitable techniques. For some absorbent articles the material laminated with the elastic material is material already existing for another reason in an absorbent article, such as a topsheet, or for other absorbent articles it could be a material specifically designed to cover the elastic in the waistband region only. Therefore, with regard to waistbands that are externally attached to the inside surface (i.e., body-facing side) of the article, a material specifically designed to cover the elastic material can be used. Therefore, it can be beneficial to provide a waistband that is both covered with a material and provided at the longitudinal edges of the article.
Waistbands that are attached to the external, inside surface of the article can be attached using a variety of means, including mechanically attached, adhesively attached, thermally attached, co-formed, and so forth. The most typical way in the industry to attach a waistband to the external surface is adhesive bonding. Adhesive equipment applications typically cost less than comparable mechanical applications, are readily known in the industry, and perform well on most waistband applications, particularly for waistbands that are positioned on an internal surface of the diaper (i.e. sandwiched) by existing materials such as topsheet and or backsheet. Sandwiching the waistband ensures that any of the adhesive applied to attach the waistband is covered and is not in direct contact with the user.
With externally applied waistbands, however, problems can occur that are detrimental to the efficacy of the absorbent article and have not been resolved completely within high speed absorbent article manufacturing applications. Most predominantly, a portion of the adhesive can become exposed to the user surface of the article and stick to the user during use and removal of the product, or otherwise make it difficult for the product to be prepared for application to the user. The adhesive can become exposed through a variety of ways. For instance, variations in the waistband attachment can lead to the lateral edges (i.e., left and right side edges) folding over or rolling up thereby exposing the underside of the waistbands and the adhesive. Further, the adhesively attached waistbands can snag on various componentry of the equipment during subsequent manufacturing or stick to various processes. In addition, adhesives can take time to solidify in the manufacturing process. If there are other processes downstream of the waistband attachment process, there may not be sufficient time for the adhesive to solidify and thus, waistbands can be easily pulled off of the article in the process with a very low force. Additionally, many times the adhesive is applied to a layer of the article such as the topsheet, and variation related to attaching the waistband, particularly in high speed manufacturing processes, can lead to an edge of the adhesive becoming exposed on one side or the other.
An approach to address the issues created with adhesive bonding of externally applied waistbands is to mechanically attach them. A mechanical attachment process can bond the waistband to the article immediately so there is smaller risk that the waistband will fall off during subsequent processing. In addition, mechanical attachments are not tacky, so even if a portion of the waistband rolls up, it will not stick to the user. Nevertheless, mechanical attachment presents several other issues, particularly in the central absorbent region of an article—especially when waistbands are attached to the chassis after the absorbent core and the chassis have already been combined. For instance, mechanical attachment can create holes that can lead to leaks of bodily exudates through the outer cover of the absorbent article. Variations in the process or the equipment manufacture can also make it difficult to create adequate bonds. In addition, mechanical bonding over the absorbent core of the absorbent article can be ineffective if the mechanical bond contacts airfelt or absorbent gel material (AGM) that is distributed within the absorbent core. Airfelt is wood pulp based and does not melt and does not bond well to the rest of the polymers in the article, leading to poor bonding. AGM can burn and become dark when subjected to a mechanical bonding process and also does not chemically pair well with other polymers, such as polypropylene. As a result, poor bonding or no bonding can occur.
Therefore, it would be advantageous to have an externally applied waistband that addresses the problems associated with adhesively bonding at the edges, namely, exposed adhesive, and premature falling off in the process. It would also be advantageous to have an externally applied waistband that addresses the problems associated with mechanically bonding near the absorbent core, namely, holes in the outer cover and burnt spots. It would further be advantageous to have an externally applied waistband that is attached at or near the longitudinal edges of the article to prevent large gathers that may be perceived as gaps and that is laminated to a nonwoven material to protect the user from the high friction materials of the elastomer.
In one form, a disposable absorbent article comprises: a front waist region, a back waist region, and a crotch region disposed between the front and back waist regions; a longitudinal axis and a lateral axis; a front waist edge, a back waist edge, a first side edge extending longitudinally and a second side edge extending longitudinally; a chassis comprising a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet; a waist gasketing element comprising a proximal end edge, a distal end edge, a first side edge and a second side edge, and an elastic material; a leg gasketing element comprising a proximal end edge, a distal end edge, a first side edge and a second side edge, and an elastic material, wherein at least a portion of the leg gasketing element is mechanically bonded with the chassis; and wherein at least a portion of the waist gasketing element is adhesively attached to the chassis and wherein at least a portion of the waist gasketing element is mechanically bonded with the leg gasketing element in a region where the leg gasketing element is mechanically bonded with the chassis.
In another form, a disposable absorbent article comprises: a front waist region, a back waist region, and a crotch region disposed between the front and back waist regions; a longitudinal axis and a lateral axis; a front waist edge, a back waist edge, a first side edge extending longitudinally and a second side edge extending longitudinally; a chassis comprising a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet; a waist gasketing element comprising a proximal end edge, a distal end edge, a first side edge and a second side edge, and an elastic material; a leg gasketing element connected with the chassis and comprising a proximal end edge, a distal end edge, a first side edge and a second side edge, and an elastic material; and wherein mechanical bonds connect the waist gasketing element with at least one of the chassis and the leg gasketing element; and wherein at least one mechanical bond comprises a region of solidified material, wherein the at least one mechanical bond defines a depth Bd extending from an outer surface of the waist gasketing element to an upper surface of the region of the solidified material, the at least one mechanical bond comprising a grommet region where the region of solidified material transitions to fibrous regions of the waist gasketing element, the grommet region defining a width Bw, and wherein a ratio of the width Bw to the depth Bd is 1:1 or less.
In yet another form, a disposable absorbent article comprises: a front waist region, a back waist region, and a crotch region disposed between the front and back waist regions; a longitudinal axis and a lateral axis; a front waist edge, a back waist edge, a first side edge extending longitudinally and a second side edge extending longitudinally; a chassis comprising a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet; a waist gasketing element joined to the chassis and comprising a first nonwoven, an elastic film and a plurality of ultrasonic bonds; wherein the absorbent article comprises a Waistband Breathability of at least 200 g/m2/24 hrs.
The following term explanations may be useful in understanding the present disclosure:
“Absorbent article” is used herein to refer to consumer products whose primary function is to absorb and retain soils and wastes. Absorbent articles can comprise sanitary napkins, tampons, panty liners, interlabial devices, wound dressings, wipes, disposable diapers including taped diapers and diaper pants, inserts for diapers with a reusable outer cover, adult incontinent diapers, adult incontinent pads, and adult incontinent pants. The term “disposable” is used herein to describe absorbent articles which generally are not intended to be laundered or otherwise restored or reused as an absorbent article (e.g., they are intended to be discarded after a single use and may also be configured to be recycled, composted or otherwise disposed of in an environmentally compatible manner).
The term “feminine hygiene articles” refers to disposable absorbent articles used by women for catamenial protection. Such feminine hygiene articles may include sanitary napkins, tampons, interlabial products, incontinence devices, and pantiliners. Non-limiting examples of panty liners and sanitary napkins include those disclosed in U.S. Pat. Nos. 4,324,246; 4,463,045; 4,342,314; 4,556,146; 4,589,876; 4,687,478; 4,950,264; 5,009,653; 5,267,992; and 6,004,893, which are all incorporated by reference herein.
An “elastic,” “elastomer” or “elastomeric” refers to materials exhibiting elastic properties, which include any material that upon application of a force to its relaxed, initial length can stretch or elongate to an elongated length more than 10% greater than its initial length and will substantially recover back to about its initial length upon release of the applied force.
As used herein, the term “joined” encompasses configurations whereby an element is directly secured to another element by affixing the element directly to the other element and configurations whereby an element is indirectly secured to another element by affixing the element to intermediate member(s), which in turn are affixed to the other element.
The term “substrate” is used herein to describe a material which is primarily two-dimensional (i.e. in an XY plane) and whose thickness (in a Z direction) is relatively small (i.e. 1/10 or less) in comparison to its length (in an X direction) and width (in a Y direction). Non-limiting examples of substrates include a web, layer or layers of fibrous materials, nonwovens, and films and foils such as polymeric films or metallic foils. These materials may be used alone or may comprise two or more layers laminated together. As such, a web is a substrate.
The term “nonwoven” refers herein to a material made from continuous (long) filaments (fibers) and/or discontinuous (short) filaments (fibers) by processes such as spunbonding, meltblowing, carding, and the like. In some configurations, a nonwoven may comprise a polyolefin based nonwoven, including but not limited to nonwovens having polypropylene fibers and/or polyethylene fibers and/or bicomponent fibers comprising a polyolefin and/or blends of fibers containing cotton or other organic materials. Nonlimiting examples of suitable fibers include spunbond, spunlaid, meltblown, spunmelt, solvent-spun, electrospun, carded, film fibrillated, melt-film fibrillated, air-laid, dry-laid, wet-laid staple fibers, hydroentangled, and other nonwoven web materials formed in part or in whole of polymer fibers as known in the art, and workable combinations thereof. Nonwovens do not have a woven or knitted filament pattern. It is to be appreciated that nonwovens having various basis weights can be used in accordance with the present disclosure. For example, some nonwovens may have a basis weight of at least about 8 gsm, 12 gsm, 16 gsm, 20 gsm, 25 gsm, 30 gsm, 40 gsm, or 65 gsm. Some nonwovens may have basis weights of about 8 gsm to about 65 gsm, specifically reciting all 1 gsm increments within the above-recited ranges and all ranges formed therein or thereby.
It is to be appreciated that films having various basis weights can be used in accordance with the present disclosure. For example, some films may have a basis weight of at least about 8 gsm, 12 gsm, 16 gsm, 20 gsm, 25 gsm, 30 gsm, 40 gsm, or 60 gsm. Some films may have basis weight of about 8 gsm to about 60 gsm, specifically reciting all 1 gsm increments within the above-recited ranges and all ranges formed therein or thereby.
Components of the disposable absorbent articles (i.e., diaper, disposable pant, adult incontinence article, sanitary napkin, pantiliner, etc.) described in this specification can at least partially be comprised of bio-sourced content as described in US 2007/0219521A1 Hird et al published on Sep. 20, 2007, US 2011/0139658A1 Hird et al published on Jun. 16, 2011, US 2011/0139657A1 Hird et al published on Jun. 16, 2011, US 2011/0152812A1 Hird et al published on Jun. 23, 2011, US 2011/0139662A1 Hird et al published on Jun. 16, 2011, and US 2011/0139659A1 Hird et al published on Jun. 16, 2011. These components include, but are not limited to, topsheet nonwovens, backsheet films, backsheet nonwovens, side panel nonwovens, barrier leg cuff nonwovens, super absorbent, nonwoven acquisition layers, core wrap nonwovens, adhesives, fastener hooks, and fastener landing zone nonwovens and film bases. In at least one embodiment, a disposable absorbent article component comprises a bio-based content value from about 10% to about 100% using ASTM D6866-10, method B, in another embodiment, from about 25% to about 75%, and in yet another embodiment, from about 50% to about 60% using ASTM D6866-10, method B. In order to apply the methodology of ASTM D6866-10 to determine the bio-based content of any disposable absorbent article component, a representative sample of the disposable absorbent article component must be obtained for testing. In at least one embodiment, the disposable absorbent article component can be ground into particulates less than about 20 mesh using known grinding methods (e.g., Wiley® mill), and a representative sample of suitable mass taken from the randomly mixed particles.
The term “machine direction” (MD) is used herein to refer to the direction of material flow through a process. In addition, relative placement and movement of material can be described as flowing in the machine direction through a process from upstream in the process to downstream in the process.
The term “cross direction” (CD) is used herein to refer to a direction that is generally perpendicular to the machine direction.
The term “taped diaper” (also referred to as “open diaper”) refers to disposable absorbent articles having an initial front waist region and an initial back waist region that are not fastened, pre-fastened, or connected to each other as packaged, prior to being applied to the wearer. A taped diaper may be folded about the lateral centerline with the interior of one waist region in surface to surface contact with the interior of the opposing waist region without fastening or joining the waist regions together. Example taped diapers are disclosed in various suitable configurations in U.S. Pat. Nos. 5,167,897, 5,360,420, 5,599,335, 5,643,588, 5,674,216, 5,702,551, 5,968,025, 6,107,537, 6,118,041, 6,153,209, 6,410,129, 6,426,444, 6,586,652, 6,627,787, 6,617,016, 6,825,393, and 6,861,571; and U.S. Patent Publication Nos. 2013/0072887 A1; 2013/0211356 A1; and 2013/0306226 A1, which are all incorporated by reference herein.
The term “pant” (also referred to as “training pant”, “pre-closed diaper”, “diaper pant”, “pant diaper”, and “pull-on diaper”) refers herein to disposable absorbent articles having a continuous perimeter waist opening and continuous perimeter leg openings designed for infant or adult wearers. A pant can be configured with a continuous or closed waist opening and at least one continuous, closed, leg opening prior to the article being applied to the wearer. A pant can be preformed or pre-fastened by various techniques including, but not limited to, joining together portions of the article using any refastenable and/or permanent closure member (e.g., seams, heat bonds, pressure welds, adhesives, cohesive bonds, mechanical fasteners, etc.). A pant can be preformed anywhere along the circumference of the article in the waist region (e.g., side fastened or seamed, front waist fastened or seamed, rear waist fastened or seamed). Example diaper pants in various configurations are disclosed in U.S. Pat. Nos. 4,940,464; 5,092,861; 5,246,433; 5,569,234; 5,897,545; 5,957,908; 6,120,487; 6,120,489; 7,569,039 and U.S. Patent Publication Nos. 2003/0233082 A1; 2005/0107764 A1, 2012/0061016 A1, 2012/0061015 A1; 2013/0255861 A1; 2013/0255862 A1; 2013/0255863 A1; 2013/0255864 A1; and 2013/0255865 A1, all of which are incorporated by reference herein.
For the purposes of a specific illustration,
As shown in
As shown in
As shown in
It is to also be appreciated that a portion or the whole of the absorbent article 100 may also be made laterally extensible. The additional extensibility may help allow the absorbent article 100 to conform to the body of a wearer during movement by the wearer. The additional extensibility may also help, for example, the user of the absorbent article 100, including a chassis 102 having a particular size before extension, to extend the front waist region 116, the back waist region 118, or both waist regions of the absorbent article 100 and/or chassis 102 to provide additional body coverage for wearers of differing size, i.e., to tailor the diaper to an individual wearer. Such extension of the waist region or regions may give the absorbent article a generally hourglass shape, so long as the crotch region is extended to a relatively lesser degree than the waist region or regions, and may impart a tailored appearance to the article when it is worn.
As previously mentioned, the absorbent article 100 may include a backsheet 136. The backsheet 136 may also define the outer surface 134 of the chassis 102. The backsheet 136 may be impervious to fluids (e.g., menses, urine, and/or runny feces) and may be manufactured in part from a thin plastic film, although other flexible, liquid impervious materials may also be used. The backsheet 136 may prevent the exudates absorbed and contained in the absorbent core from wetting articles which contact the absorbent article 100, such as bedsheets, pajamas and undergarments. The backsheet 136 may also comprise a woven or nonwoven material, polymeric films such as thermoplastic films of polyethylene or polypropylene, and/or multi-layer or composite materials comprising a film and a nonwoven material (e.g., having an inner film layer and an outer nonwoven layer). The backsheet 136 may also comprise an elastomeric film. An example backsheet 136 may be a polyethylene film having a thickness of from about 0.012 mm (0.5 mils) to about 0.051 mm (2.0 mils). Exemplary polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation BR-120 and BR-121 and by Tredegar Film Products of Terre Haute, Ind., under the designation XP-39385. The backsheet 136 may also be embossed and/or matte-finished to provide a more clothlike appearance. Further, the backsheet 136 may permit vapors to escape from the absorbent core (i.e., the backsheet is breathable) while still preventing exudates from passing through the backsheet 136. The size of the backsheet 136 may be dictated by the size of the absorbent core 142 and/or particular configuration or size of the absorbent article 100.
Also described above, the absorbent article 100 may include a topsheet 138. The topsheet 138 may also define all or part of the inner surface 132 of the chassis 102. The topsheet 138 may be compliant, soft feeling, and non-irritating to the wearer's skin. It may be elastically stretchable in one or two directions. Further, the topsheet 138 may be liquid pervious, permitting liquids (e.g., menses, urine, and/or runny feces) to penetrate through its thickness. A topsheet 138 may be manufactured from a wide range of materials such as woven and nonwoven materials; apertured or hydroformed thermoplastic films; apertured nonwovens, porous foams; reticulated foams; reticulated thermoplastic films; and thermoplastic scrims. Woven and nonwoven materials may comprise natural fibers such as wood or cotton fibers; synthetic fibers such as polyester, polypropylene, or polyethylene fibers; or combinations thereof. If the topsheet 138 includes fibers, the fibers may be spunbond, carded, wet-laid, meltblown, hydroentangled, or otherwise processed as is known in the art.
Topsheets 138 may be selected from high loft nonwoven topsheets, apertured film topsheets and apertured nonwoven topsheets. Apertured film topsheets may be pervious to bodily exudates, yet substantially non-absorbent, and have a reduced tendency to allow fluids to pass back through and rewet the wearer's skin. Exemplary apertured films may include those described in U.S. Pat. Nos. 5,628,097; 5,916,661; 6,545,197; and 6,107,539, which are all incorporated by reference herein.
As mentioned above, the absorbent article 100 may also include an absorbent assembly 140 that is joined to the chassis 102. As shown in
Some absorbent core embodiments may comprise fluid storage cores that contain reduced amounts of cellulosic airfelt material. For instance, such cores may comprise less than about 40%, 30%, 20%, 10%, 5%, or even 1% of cellulosic airfelt material. Such a core may comprise primarily absorbent gelling material in amounts of at least about 60%, 70%, 80%, 85%, 90%, 95%, or even about 100%, where the remainder of the core comprises a microfiber glue (if applicable). Such cores, microfiber glues, and absorbent gelling materials are described in U.S. Pat. Nos. 5,599,335; 5,562,646; 5,669,894; and 6,790,798 as well as U.S. Patent Publication Nos. 2004/0158212 A1 and 2004/0097895 A1, which are all incorporated by reference herein.
As previously mentioned, the absorbent article 100 may also include elasticized leg gasketing elements 156 and a waist gasketing element 158. It is to be appreciated that the leg gasketing elements 156 can be and are sometimes also referred to as leg bands, side flaps, barrier cuffs, elastic cuffs, leg gasketing systems, or gasketing cuffs. The elasticized leg gasketing elements 156 may be configured in various ways to help reduce the leakage of body exudates in the leg regions. Example leg gasketing elements 156 may include those described in U.S. Pat. Nos. 3,860,003; 4,909,803; 4,695,278; 4,795,454; 4,704,115; and U.S. Patent Publication No. 2009/0312730 A1, which are all incorporated by reference herein.
As shown in
The waist gasketing element 158 may provide improved fit and containment and may be a portion or zone of the absorbent article 100 that may elastically expand and contract to dynamically fit a wearer's waist. The waist gasketing element 158 may comprise a laterally extending proximal end edge 174 and a longitudinally opposing and laterally extending distal end edge 176. The waist gasketing element 158 may also have a first side edge 178 and a second side edge 180. Both side edges 178 and 180 extend longitudinally between the proximal end edge 174 and the distal end edge 176. The waist gasketing element 158 may be constructed in a number of different configurations including those described in U.S. Pat. Nos. 4,515,595 and 5,151,092, which are all incorporated by reference herein.
It is to be appreciated that the waist gasketing element 158 may be located in various positions relative to various diaper components. For example, the waist gasketing element 158 may be positioned longitudinally inwardly from the waist edges 120, 122 of the absorbent article and/or toward the lateral edges 148, 150 (
At least a portion of the waist gasketing element 158 may be attached to the chassis 102 with an adhesive 170. The waist gasketing element 158 can define at least one adhesive zone 171 of adhesive 170 on the surface of the waist gasketing element 158 that adheres to the chassis 102. It is to be appreciated that the adhesive zone 171 of adhesive 170 may define various sizes and shapes relative to the waist gasketing element 158. For example, as shown in
It is to be appreciated that various methods may be used to create mechanical bonds 172. In some configurations, components of the waist gasketing element 158 may be mechanically (pressure) bonded to other substrates with the application of pressure (and optionally heat) in various ways, such as for example, the mechanical bonding devices and methods disclosed in in U.S. Pat. Nos. 4,854,984; 6,248,195; 8,778,127; 9,005,392; 9,962,297; and 10,052,237, which are all incorporated by reference herein. In some configurations, the waist gasketing element 158 may be mechanically (pressure and vibrational energy converted to thermal energy) bonded with the use of ultrasonic bonding methods configured in various ways, such as for example linear or rotary type configurations, and such as disclosed for example in U.S. Pat. Nos. 3,113,225; 3,562,041; 3,733,238; 5,110,403; 6,036,796; 6,508,641; and 6,645,330. In some configurations, mechanical bonding processes may melt and/or yield material from the bonded substrates to create mechanical bonds 172 that include regions of relatively stiff, solidified material. For example,
With some mechanical bonds 172, such as shown in
It is also to be appreciated that in some configurations, the mechanical bonds 172 may be positioned so as to overlap with other mechanical bonds. For example,
Taped diapers may be manufactured and provided to consumers in a configuration wherein the front waist region and the back waist region are not fastened, pre-fastened, or connected to each other as packaged, prior to being applied to the wearer. For example, the taped diaper 100T may be folded about a lateral centerline with the interior surface 132 of the first waist region 116 in surface to surface contact with the interior surface 132 of the second waist region 118 without fastening or joining the waist regions together. The rear side panels 104 and 106 and/or the front side panels 108 and 110 and/or the leg gasketing elements 156 may also be folded laterally inward toward the inner surfaces 132 of the waist regions 116 and 118.
The absorbent article 100 may also include various configurations of fastening elements to enable fastening of the front waist region 116 and the back waist region 118 together to form a closed waist circumference and leg openings once the absorbent article is positioned on a wearer. For example, as shown in
With continued reference to
Referring now to
As previously mentioned, the fastening members 162 and 164 may be constructed from various materials and may be constructed as a laminate structure. The fastening members 162 and 164 may also be adapted to releasably and/or refastenably engage or connect with another portion of the diaper 100. For example, as shown in
The absorbent article 200 also includes a waist gasketing element 258, which is schematically illustrated to include a laminate of an elastic film 220 bonded with a first nonwoven 216 and a second nonwoven 218. The first nonwoven 216 may be bonded to the second nonwoven 218 through any suitable technique, such as ultrasonic bonding, adhesive bonding, and so forth. One or both of the nonwovens 216 and 218 may be, for example, an elastomeric nonwoven or a non-elastic nonwoven. It is also be appreciated that the first nonwoven 216 and the second nonwoven 218 may be the same size or may have different sizes and may define the same or different widths and/or lengths. Further, while the waist gasketing element 258 is shown in
The absorbent article comprising the waist gasketing element, particularly a waist gasketing element 258 comprising a film 220, may exhibit a Waistband Breathability of at least 200 g/m2/24 hrs, or at least 300 g/m2/24 hrs, or at least 500 g/m2/24 hrs, or at least 600 g/m2/24 hrs, or from 200 g/m2/24 hrs to about 3500 g/m2/24 hrs, reciting for said range every 10 g/m2/24 hrs increment therein, according to the WTVR Test Method herein. In nonlimiting examples, breathability of the waistband-chassis composite may vary, such that breathability at one longitudinal position is less than the breathability value at a different longitudinal position and/or breathability values at different lateral positions may vary. The chassis 102 may comprise a Waist Area Breathability of at least 3000 g/m2/24 hrs, or at least 3100 g/m2/24 hrs, or at least 3200 g/m2/24 hrs, from 2900 g/m2/24 hrs to 3500 g/m2/24 hrs, reciting for said range every 50 g/m2/24 hrs increment therein, according to the WTVR Test Method herein.
Mechanical bonds 272 are shown in
A central portion of the example waist gasketing element 258 is attached to the chassis 202 with an adhesive 270. The waist gasketing element 258 can define at least one adhesive zone 271 of adhesive 270 on the surface of the waist gasketing element 258 that adheres to the chassis 202. As shown in
As shown in
Referring now to the back waist region 318, the waist gasketing element 358 is positioned relative to the chassis 302 such that it is offset in the machine direction MD from a back waist edge 322 by an offset distance OD. The offset distance OD 0 mm, such that the distal end edge 376 of the waist gasketing elements 358 positioned in the back waist region 318 is coterminous with back waist edge 322 and waist gasketing elements 358 positioned in the front waist region 316 is coterminous with front waist edge 344. Alternatively, the offset distance OD can be in the range of about 1 mm to about 10 mm, or in the range of about 2 mm to about 5 mm, or in the range of about 5 mm to about 20 mm, or in the range of about 20 mm to about 50 mm, or can be about 10 mm. The waist gasketing element 358 is positioned in the front waist region 316 and may also be offset in the machine direction MD from a front waist edge 344 by an offset distance OD. The offset distance OD can be 0 mm or be in the range of about 1 mm to about 10 mm, or in the range of about 2 mm to about 5 mm, or in the range of about 5 mm to about 20 mm, or in the range of about 20 to about 40 mm, or can be about 10 mm.
Although absorbent articles may be configured to include a waist gasketing element 158 and side panels 104, 106 having corrugations and associated stretch properties that may be separated from each other along a lateral width, it is to be appreciated that absorbent articles 100 may be configured with corrugated components combined in ways to help mitigate reductions in softness and/or comfort. For example, in some configurations, the waist gasketing element 158 and side panels 104, 106 may be provided with an elastic material, such as a film and/or strands, joined to other components in a stretched state. When the elastic materials relax, corrugations are formed in the corresponding waist gasketing element 158 and side panels 104, 106. In turn, the waist gasketing element 158 and side panels 104, 106 may be stretchable to the extent that the corrugations allow the waist gasketing element 158 and side panels 104, 106 to elongate. For example,
As shown in
The first and second fastening members 462, 464 can define a tab axis 426 extending in the cross direction through a longitudinal midpoint of each of the first and second fastening members 462, 464. The tab axis 426 may be parallel to a lateral axis of the absorbent article 400. The waist gasketing element 458 can define a waist gasketing element axis 424 extending in the cross direction through a longitudinal midpoint of the waist gasketing element 458. The waist gasketing element axis 424 may be parallel to the tab axis 426. In accordance with various configurations, the waist gasketing element axis 424 may be offset from the tab axis 426 in a direction towards the distal end edge 476 by an axis offset distance AOD. In
When the fastening members 462 and 464 are pulled around the waist of the wearer and connected with a front waist region to form a closed waist circumference a direct line of tension is formed between the fastening members 462 and 464. Offsetting the waist gasketing element axis 424 from the tab axis 426 by a distance AOD can beneficially keep the waist gasketing element 458 from being aligned with this direct line of tension. Thus, configuring the absorbent article 400 such that the waist gasketing element axis 424 is spaced away from the tab axis 426 may allow for the waist gasketing element 458 to be exposed to less force levels than the levels of force to which the fastening members 462 and 464 are exposed. As a result, the stretchable waist gasketing element axis 424 can retain energy that can be used to close gaps when the wearer bends yet not impact the overall span of the users the article can fit.
Referring now to
Still referring to
The example arrangement of bond sites 675 illustrated in
As shown in
The bond sites 675 connecting each peak 680 and valley 672 may be spaced in the machine direction by a distance A. The distance A may in the range of about 0.1 mm to about 1 mm, or in the range of about 1 mm to about 3 mm, or in the range of about 2 to about 10 mm. In some embodiments, the distance A is about 0.5 mm. Laterally adjacent bond sites 675 in a wave can be separated in the cross direction CD by a distance B. The distance B may in the range of about 2 mm to about 6 mm. The distance B may in the range of about 3 mm to about 5 mm, or about 5 mm to about 15 mm. In some embodiments, the distance B is about 4.8 mm. Longitudinally adjacent bond sites 675 in a consecutive waves can be separated in the machine direction MD by a distance C. The distance C may in the range of about 2 mm to about 10 mm. The distance C may in the range of about 7 mm to about 20 mm. In some embodiments, the distance C is about 4 mm.
Referring now to
The first end adhesive portion 721 may be positioned in the cross direction CD between the first adhesive-free zone 773 and the adhesive zone 771. The second end adhesive portion 723 may be positioned in the cross direction CD between the adhesive zone 771 and the second adhesive-free zone 775. As shown, the first and second end adhesive portions 721 and 723 may extend in the machine direction MD the entire longitudinal length of the waist gasketing elements 758A and 758B. The application of the adhesive 770 in the first and second end adhesive portions 721 and 723 can beneficially improve the total strength of the mechanical bonds 772, especially when the mechanical bonds 772 are relatively small and have an open pattern.
In some configurations, the width of the first end adhesive portion 721 and a second end adhesive portion 723 in the machine direction is reduced in order to increase the width of an adhesive free zone 777, sometimes referred to as a pocket, that is positioned therebetween. During production of the waist gasketing laminate 759, the adhesive 770 can be applied continuously to the laminate in the first end adhesive portion 721 and the second end adhesive portion 723, while the adhesive 770 applied to the adhesive zone 771 can be applied intermittently. Due to the use of two different adhesive delivery assemblies, a small gap Gin the cross direction CD may be defined between the adhesive zone 771 and each of the first and second end adhesive portions 721 and 723. However, while a gap G is depicted for illustration purpose, this gap may or may not exist as a result of the specific adhesive application that is used. Furthermore, the adhesives in any of the portions 721, 723, and 771 can be applied to the waistband gasketing laminate 759 or can be applied to the chassis.
Referring now to
As shown in
It is to be appreciated the waist gasketing element 858 may be configured such that the width WDZ1 of the first dead zone DZ1 may be equal to or different from the width WDZ2 of the second zone DZ2. In some configurations, the width WDZ1 of the first dead zone DZ1 width and the width WDZ2 of the second dead zone DZ2 may each be equal to, less than, or greater than a width of the adhesive-free zones of the waist gasketing element 858.
Water Vapor Transmission Rate (WVTR) is measured using a wet-cup approach to determine the rate for waistband regions of taped diapers in the fully extended state. Depending on the structure to be characterized, specimens excised from waistband regions may contain either all layers of the article (to obtain the Waistband Breathability) or all layers with the exception of a waistband material (to obtain the Waist Area Breathability). A cylindrical cup is filled with water to a predetermined level so as to achieve a target headspace between the water surface, and an extended specimen is sealed over the cup's upper opening. After heating the assembled cup for a specified time in an oven, the mass of water lost during the incubation period (corresponding to the vapor transmitted during this same period) is determined gravimetrically. Glass, straight-walled cylindrical vials 95 mm in height and with 17.8 mm internal diameter at the threaded opening are used as WVTR test cups. Articles are preconditioned at 23° C.±2 C.° and 50%±2% relative humidity for two hours prior to testing.
If the structure to be characterized is the entire article thickness in the waistband region, a specimen contains all layers of the waistband (also referred to as the “waist gasketing element”) and all layers of the article in the thickness direction of the waistband region of the article. The test specimen is removed from the article using scissors so as not impart any contamination or distortion to the specimen. The specimen is taken from an area that is centered over the intersection of the longitudinal and lateral midpoints of the waistband itself that is preferably free from any core, cuff or ear material if possible. The test specimen is cut to about 60 mm long by 60 mm wide. If a specimen of 60 mm by 60 mm cannot be retrieved, ensure the minimum dimension of the specimen is 18 mm or greater. A total of three specimens are prepared in this way from three separate like sample articles. And the WVTR derived below is reported as the Waistband Breathability.
If the structure to be characterized is the waistband region without the waistband material present, a specimen is prepared generally in the same way previously described. However, in this case, the waistband material is peeled away from the underlying materials using freeze spray as needed so as to not distort, tear, or otherwise damage underlying layers. If freeze spray is utilized, the specimen must be equilibrated at the aforementioned environmental conditions for 2 hours prior to testing. A total of three specimens are required for each type of material being evaluated. And the WVTR derived below is reported as the Waist Area Breathability.
With the body-facing surface of a specimen facing a fixed horizontal surface such as a lab bench, one of the edges of the specimen in the extensible direction is affixed to the fixed horizontal surface using masking tape. The specimen is then fully extended, and the opposite edge is likewise secured. In this iteration, the term “fully extended” means that the elastomeric material is stretched as far as the non-extensible material(s) will allow without resulting in their permanent deformation. Thus, the non-extensible materials of the specimen are taught but essentially unstrained. A circle is marked on the specimen with a diameter corresponding to the diameter of the threaded upper opening of a test cup (17.8 mm). The test cup is charged with distilled water accurately to a level 25.0±0.1 mm from the upper lip of the cup's opening. The specimen is placed, body-facing surface of the laminate downward, over the charged cup's opening. The specimen is extended such that the marked circle aligns with the cup's opening and secured around the cup's circumference with an elastic band. The specimen is further sealed by wrapping 0.25″ wide Teflon tape around the cup's circumference. The Teflon tape is applied up to the top edge of the cup but does not cover any portion of the cup's opening. Enough Teflon tape is applied such that the remaining portion of the specimen hanging below the elastic band is sealed. The mass of the cup assembly is weighed to the nearest 0.0001 gram and recorded as the starting mass (SM). Repeat in like fashion for the remaining specimens. The cup assemblies are placed upright in a mechanical convection oven (e.g. Lindberg Blue M oven available from Thermo Scientific, or equivalent) maintained at 38±2° C. for 24 hours. Throughout all handling steps, any contact between the water contained in each vial and the specimen taped over the vial is strictly avoided. After 24 hours has elapsed, the cup assemblies are removed from the oven and allowed to equilibrate to room temperature. The mass of each cup assembly is measured to the nearest 0.0001 gram and recorded at the final mass (FM). The WVTR is calculated using the following equation:
WVTR (g/m2/24 hours)=([SM (g)−FM (g)]/specimen surface area (m2))/24 hrs
Calculate the arithmetic mean WVTR for each type of material and report to the nearest 1 g/m2/24 hrs, noting if the waistband material itself was present or not present. If the waistband is present, the WVTR is the Waistband Breathability. If the waist band is not present, the WVTR is the Waist Area Breathability.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/930,181, filed on Nov. 4, 2019; U.S. Provisional Patent Application No. 62/930,198, filed on Nov. 4, 2019; and U.S. Provisional Patent Application No. 62/930,808, filed on Nov. 5, 2019, which are all hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62930181 | Nov 2019 | US | |
| 62930198 | Nov 2019 | US | |
| 62930808 | Nov 2019 | US |
