A tape-type absorbent article having a front elastic waistband and a rear elastic waistband

Abstract

A tape-type absorbent article (20) having a front elastic waistband (100) adjacent to the front waist edge (10) and a rear elastic waistband (200) adjacent to the rear waist edge (12). When measured by the waistband elasticity measuring method disclosed herein, the front elastic waistband has a front waistband elasticity in the range of about 0.03 N to about 0.32 N, and the rear elastic waistband has a rear waistband elasticity higher than the front waistband elasticity.

Description

Technical Field

[0001] The present invention relates to absorbent articles for personal hygiene such as baby diapers and adult incontinence products.

Background Art

[0002] Diaper-type disposable absorbent articles include an absorbent core disposed between a liquid-permeable topsheet and a liquid-impermeable backsheet. Urine is captured by the absorbent article through the topsheet and absorbed by the absorbent material. Tape-type diapers include a pair of rear ear portions having tapes that can be removably attached to the landing zone at the front of the diaper. The rear ear portions are typically elasticized so that the tension around the waist can be adjusted by a caregiver. On the other hand, pants-type diapers have side seals and are worn like underwear. Although it is common for pants-type diapers to include an elastic material such as an elastic film or elastic strands at the waist level, it is rarer for tape-type diapers to be compatible with a rear elastic waistband and even rarer for them to be compatible with an elastic front waistband.

[0003] The elastic front waistband can reduce or prevent any gaps at the front edge of the diaper, thus providing additional leakage protection at the front of the diaper, especially when the baby is sleeping face down. Also, an extensible front waistband can adjust the fit for a baby in different activity / body stages such as different lying positions. By combining with an extensible rear waistband, the entire body of the baby can obtain 360-degree extensible protection.

[0004] When the elastic force of the front waistband is too high, in order to be able to attach the rear ear tape to the front landing zone due to the many wrinkles caused by the high front waist force, it has been found that the caregiver needs to stretch the front waistband several times to make the front waistband sufficiently flat. Even after the diaper is applied to the body, the very high force of the front waistband can cause a curved U-shaped deformation of the front waist edge of the diaper. This U-shaped form makes the diaper look saggy, not having good fit, and more importantly, a part of the rear tape may come into contact with the skin, which can be uncomfortable for the skin of the wearer.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, there is a need for an absorbent article that addresses the above problems, specifically, has good fluid management characteristics, is easy to apply, and is comfortable for the wearer during use.

Means for Solving the Problems

[0006] In a first aspect, the present invention relates to a tape-type absorbent article having a front half region with a front waist edge, a rear half region with a rear waist edge, a first longitudinal edge and a second longitudinal edge, a side facing the wearer, and a side facing the clothing. The tape-type absorbent article includes a topsheet on the side facing the wearer, a backsheet on the side facing the clothing, an absorbent core between the topsheet and the backsheet, and a pair of rear ears each having a fastening tab removably attachable to a landing zone on the side of the absorbent article facing the clothing in the front half region of the article.

[0007] According to the present invention, the absorbent article further comprises a front elastic waistband adjacent to the front waist edge of the article and a rear elastic waistband adjacent to the rear waist edge. The present invention is based on the discovery that the front waistband force should be within a specific relatively low range instead of being too high. Therefore, the front elastic waistband should have a front waistband elastic force in the range of about 0.03 N to about 0.32 N when measured by the waistband elastic force measurement method disclosed herein. The rear elastic waistband should have a rear waistband elastic force higher than the front waistband elastic force.

[0008] The front waistband and the rear waistband can be made from any suitable material, typically either a laminate including elastic strands or a laminate including a central elastic film layer, as known in the art. In a first alternative form, a continuous method for manufacturing the absorbent article of the present invention comprises - providing a continuous supply of the waistband material in the machine direction, the material having a first longitudinal half and a second longitudinal half conceptually divided by a fold line; - providing a continuous supply of elastic strands, the elastic strands being adapted to provide the desired elastic strength to each waistband; - intermittently applying an adhesive onto the elastic strands; - overlaying the elastic strands in the machine direction over the waistband material on the first half of the waistband material; - folding the second half of the waistband material along the fold line over the first half of the waistband material to obtain a continuous waistband laminate including the elastic strands sandwiched between the thus-folded waistband materials, the laminate having adhesive-bonded regions separated by non-bonded regions; - A step of cutting the waistband laminate in a machine cross direction along the dashed cutting line within the non-bonding region, where the dashed cutting line partially cuts the elastic strands and the folded waistband material, the cutting step; - A step of aligning the waistband laminate with the transverse direction of the chassis of the article; - A step of stretching the waistband laminate so that the waistband laminate breaks along the dashed cutting line to form the combined pads; - A step of cutting each combined pad along the cutting line to create separate front waistband laminates and rear waistband laminates; - A step of attaching the front waistband and the rear waistband to the chassis of the absorbent article, and can include.

[0009] This feature and further features or aspects of the present invention are disclosed in the following description and the appended claims.

Brief Description of the Drawings

[0010] This specification concludes with "Claims" that particularly and distinctly claim the invention, but it is believed that the content of this specification will be better understood by reading the following description together with the accompanying drawings.

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DETAILED DESCRIPTION OF THE INVENTION

[0011] Definition As used herein, the terms "absorbent article" or "diaper" generally refer to personal hygiene devices that are worn around the lower torso so as to surround the waist and legs of the wearer, particularly infants, toddlers, and adult incontinent individuals, and that are adapted to receive and contain urine and fecal excreta. These products are typically proposed as tape-type diapers or pant-type diapers. Tape-type diapers have a fastening system (as illustrated in FIG. 1), and when the diaper is applied to the wearer, the waist opening and the leg openings are formed by removably attaching the front waist region and the rear waist region to each other by means of a pair of rear ear portions. On the other hand, in the case of pant-type diapers, the article has a pre-formed waist opening and leg openings. The pant-type diaper is placed in position on the wearer by inserting the wearer's legs into the leg openings and sliding the pant-type diaper up to a position around the lower torso of the wearer. The pants may be pre-formed by any suitable technique, including but not limited to joining portions of the absorbent article together using re-fastenable and / or non-re-fastenable joining materials (e.g., stitching, welding, adhesives, adhesive joining materials, fasteners, etc.).

[0012] As used herein, the terms "nonwoven fabric", "nonwoven web", and "nonwoven layer" are used interchangeably. A nonwoven fabric is broadly defined as a primarily planar assembly of artificial fibers that has been given a level of structural integrity by physical and / or chemical means, excluding weaving, knitting, or papermaking. The fibers can be of natural origin, such as cotton or bamboo fibers, or of artificial origin. Synthetic fibers can be selected from the group consisting of polyolefins (such as polyethylene, polypropylene, or combinations and mixtures thereof), polyethylene terephthalate (PET), co-PET, polylactic acid (PLA), polyhydroxy alkanoid (PHA), or mixtures or combinations thereof. The fibers can be staple fibers (e.g., carded nonwoven webs / layers) or continuous fibers (e.g., spunbond or meltblown nonwoven webs / layers).

[0013] The nonwoven material can be formed from various fiber materials (PP, PE, PET, coPET, bicomponent, and mixtures thereof), and in some cases, the fibers or nonwoven fabric can be treated to improve specific fluid handling properties such as fluid permeability or fluid barrier properties.

[0014] As used herein, "dtex" refers to the unit used to indicate the fineness of filaments / fibers. This unit represents the mass of filaments / fibers in grams per 10,000 meters of length.

[0015] "Longitudinal direction" refers to the direction that extends substantially perpendicular from the waist edge of an article to the opposite waist edge and is substantially parallel to the maximum linear dimension of the article (line 80 in FIG. 1). "Transverse direction" refers to the direction perpendicular to the longitudinal direction (line 90 in FIG. 1).

[0016] "Inner" and "outer" each refer to the relative position of an element, or the surface of an element, or a group of elements. "Inner" means that the element or surface is oriented towards the inside of the article, and "outer" means that the element or surface is oriented towards the outside of the article.

[0017] "Facing the body" and "facing the clothing" each refer to the relative location of the surface of an element, or a group of elements. "Facing the body" means that the surface is closer to the wearer during use than the other surface of the elements of the group of elements. "Facing the clothing" means that the surface is oriented away from the wearer during use. The surface facing the clothing may face another article of clothing of the wearer (i.e., other than the wearable article), another article such as bedding, or the atmosphere.

[0018] "Comprise, comprising, comprises" are non-limiting terms, each identifying the presence of the subsequently described features (e.g., components), but not excluding the presence of other features (e.g., elements, steps, components known in the art or disclosed herein). These terms based on the verb "comprise" encompass the more narrow term "consisting essentially of", which excludes any element, step, or ingredient not recited that materially affects the manner in which the feature is performed, and the term "consisting of", which excludes any element, step, or ingredient not specified.

[0019] General description of an exemplary diaper according to the present invention The absorbent article of the present invention can generally be described with reference to the taped diaper 20 shown in FIGS. 1 to 3. FIG. 1 is a perspective view of an exemplary diaper in a closed state as seen when worn by a wearer. These figures are used herein as an illustration of one way to implement the present invention and are not intended to limit the scope of the claims unless otherwise indicated. Hereinafter, the words "diaper" and "absorbent article" are used interchangeably. FIG. 2 shows a top view of the side of the diaper facing the wearer with the tape open and the diaper flattened, and FIG. 3 shows a top view of the same diaper as seen from the side facing the clothing.

[0020] The absorbent article has a front edge portion 10, a rear edge portion 12, and two longitudinally extending side (lateral) edge portions 13, 14. The front edge portion 10 is the edge of the article that is disposed forward of the user during wear, and the rear edge portion 12 is the opposite edge, and together they form the waist opening of the diaper. The lateral edge portions 13, 14 each form two leg openings.

[0021] The longitudinal edge portions 13, 14 of the diaper typically extend substantially parallel to the longitudinal center line 80 of the diaper 20, and the front waist edge portion 10 and the rear waist edge portion 12 typically extend substantially parallel to the transverse center line 90 of the diaper 20. The front and rear edge portions may be straight as shown, but may be wavy, for example, due to a front navel cut.

[0022] As will be discussed in more detail below, the exemplary topsheet shown in the figures includes a primary topsheet layer 24a disposed centrally and a wider secondary topsheet layer 24b disposed beneath the primary topsheet layer 24a. The secondary topsheet layer 24b may extend laterally to the outer edges 13, 14 of the diaper or may stop laterally at an intermediate position having a barrier cuff material 36 that extends to the side of the diaper facing the wearer. The primary topsheet layer and the secondary topsheet layer can typically be joined together using an adhesive, and the primary topsheet layer is mechanically deformed such that the primary topsheet layer has a three-dimensional quilted soft feel. The exemplary tape diaper shown is formed by a combination of a leg cuff material 36 extending from a second topsheet layer 24b on the side facing the wearer and a backsheet outer cover 25b on the side facing the clothing and has a unibody structure with shaped longitudinal edges 13, 14.

[0023] However, the present invention is, of course, applicable to any type of tape diaper structure, specifically, a tape diaper having a chassis formed by a backsheet and a topsheet having substantially straight longitudinal edges, and the diaper includes separate front ears and rear ears attached to the chassis, as is also known in the art.

[0024] Before considering the front waistband 100 and the rear waistband 200, other components of the article are first generally considered herein.

[0025] Topsheet 24 The topsheet 24 is the portion of the absorbent article 20 that contacts the wearer's skin. The topsheet 24 can be joined to the backsheet 26, the absorbent core 28, the barrier leg cuffs 32-34, and / or portions of any other layer, as known to those skilled in the art. Suitable topsheets are flexible, have a soft feel, and do not irritate the wearer's skin. The topsheet typically consists of or includes at least a nonwoven layer. Further, the topsheet is liquid permeable, allowing liquid body excreta to easily penetrate its thickness. Suitable topsheets can be made from a wide range of materials such as, for example, porous foams, reticulated foams, apertured plastic films, woven materials, nonwoven materials, natural fibers (e.g., wood fibers or cotton fibers), synthetic fibers or filaments (e.g., polyester fibers, or polypropylene fibers, or bicomponent PE / PP fibers, or mixtures thereof), or combinations of natural and synthetic fibers, such as woven or nonwoven materials. The topsheet is typically a single layer, but can have one or more layers, as depicted in the figure as a double-layer laminate structure including, for example, a primary topsheet layer 24a disposed at the center of a three-dimensional shape disposed on top of a larger secondary topsheet layer 24b.

[0026] The topsheet may be apertured, may have any suitable three-dimensional features, and / or may have a plurality of embossments (e.g., bond patterns). Multicomponent topsheets having three-dimensional materials are disclosed, for example, in WO 2017 / 156197. The topsheet may also be apertured by overbonding the material and then breaking the overbond by ring rolling. Any portion of the topsheet can be coated with a skin care composition, an antibacterial agent, a surfactant, and / or other beneficial agents. The topsheet can be hydrophilic or hydrophobic, or can have hydrophilic portions or hydrophilic layers and / or hydrophobic portions or hydrophobic layers. If the topsheet is hydrophobic, the apertures will typically be present such that body excreta can pass through the topsheet.

[0027] Backsheet laminate 25 The backsheet 25 generally forms the surface facing the clothing of the absorbent article. Typically, the backsheet is disposed centrally so as to cover at least the absorbent core 28, and preferably is a laminate including a liquid-impermeable film 25a that extends beyond the absorbent core and the outer cover 25b. The backsheet film 25a is substantially rectangular. The outer cover 25b is the outermost layer of the backsheet. When the absorbent article is formed by a unibody chassis as represented in the figure, the outer cover 25b typically extends laterally beyond the longitudinal edges of the backsheet film 25a, so that the outer cover can form the outer edges of the diaper, specifically the longitudinal edges 13, 14 of the diaper, together with the topsheet (or one of the layers in the case of a laminate).

[0028] The backsheet film 25a can be joined to the topsheet 24, the outer cover material 25b, the absorbent core 28, and / or any other layer portion of the absorbent article by any attachment method known to those skilled in the art. The backsheet 25 prevents or at least suppresses body excretions absorbed and contained within the absorbent core 28 from soiling articles such as bedsheets, underwear, and / or clothing. The backsheet film is typically liquid-impermeable or at least substantially liquid-impermeable. The backsheet can be or include a thin plastic film such as a thermoplastic film having a thickness of, for example, from about 0.012 mm to about 0.051 mm. Other suitable backsheet materials may include breathable materials that allow vapor to escape from the absorbent article while still preventing or at least suppressing body excretions from passing through the backsheet.

[0029] The outer cover 25b (which may also be referred to as the backsheet nonwoven fabric) may include one or more nonwoven materials joined to the backsheet film 25a. The outer cover material 25b forms at least a portion of the surface of the absorbent article 20 that faces the clothing, and effectively "covers" the backsheet film 25a so that the film does not exist on the surface facing the clothing. The outer cover material 25b may include a bond pattern, holes, and / or three-dimensional features. The outer cover material 25b may be a hydroentangled nonwoven material.

[0030] Absorbent core 28 As used herein, the term "absorbent core" refers to a component that absorbs and contains liquids such as urine received by the absorbent article. For this reason, the absorbent core typically has a high absorption capacity compared to other components of the article. The absorbent core includes an absorbent material and a core wrap (not shown separately for simplicity). As used herein, "absorbent core" does not include any capture and distribution system, topsheet, or backsheet of the absorbent article.

[0031] The absorbent material typically includes superabsorbent polymer particles, as is known in the art. As used herein, "superabsorbent polymer" or "SAP" refers to an absorbent material, typically a crosslinked polymer material, that can absorb at least 10 times its weight of 0.9% saline when measured using the Centrifuge Retention Capacity (CRC) test. CRC measures the liquid absorbed by superabsorbent polymer particles that freely swell in excess saline. CRC is measured according to the EDANA method NWSP 241.0.R2(19). SAP can specifically have a CRC value of at least 20 g / g, specifically 20 g / g to 40 g / g. As used herein, "superabsorbent polymer particles" refers to a superabsorbent polymer material in particulate form that is fluid in the dry state.

[0032] The superabsorbent particles can be mixed with cellulose fibers or immobilized within the core wrap using an adhesive or a high-loft nonwoven layer as known in the art. The core wrap typically includes a top layer and a bottom layer, and the absorbent material is sandwiched between these layers. The core wrap may be a single material folded and attached to itself, or it may include separate top and bottom layers that can be joined to each other or otherwise bonded.

[0033] A variety of absorbent cores can also be used in the present invention. The absorbent material can also form a rectangular layer, but may have a non-rectangular outer perimeter (“shaped” core), specifically, the absorbent material may define a taper (or “dog bone” shape) along its width towards the central region of the core. In this way, the absorbent material deposition area may have a relatively narrow width in the area of the core intended to be disposed within the crotch region of the absorbent article. This can, for example, result in better wearing comfort. Other shapes such as “T-shaped”, or “Y-shaped”, or “hourglass” can also be used for the area of the absorbent material.

[0034] The absorbent material can be any conventional absorbent material known in the art. For example, the absorbent material can include a blend of cellulose fibers and superabsorbent particles (“SAP”), typically in a percentage of SAP in the range of about 50 wt% to about 75 wt% of the absorbent material. The absorbent material may also not include cellulose fibers, as known in so-called airfelt-free cores where the absorbent material consists of or is essentially composed of SAP. The absorbent material may also be a high internal phase emulsion foam.

[0035] Various absorbent core designs containing large amounts of SAP have been proposed in the past. See, for example, U.S. Patent No. 5,599,335 (Goldman), European Patent No. 1,447,066 (Busam), International Publication No. 95 / 11652 (Tanzer), U.S. Patent Application Publication No. 2008 / 0312622 (A1) (Hundorf), and International Publication No. 2012 / 052172 (Van Malderen). Specifically, the SAP printing techniques disclosed in U.S. Patent Application Publication No. 2006 / 024433 (Blessing), U.S. Patent Application Publication No. 2008 / 0312617, and U.S. Patent Application Publication No. 2010 / 51166 (A1) (both to Hundorf et al.) can be used. The absorbent core can also be an airfelt core including a high-loft central nonwoven fabric containing inter-fiber pores in which superabsorbent polymer particles are at least partially distributed.

[0036] However, the present disclosure is not limited to a particular type of absorbent core. The absorbent core typically also includes one or more adhesives, such as auxiliary adhesives applied between the inner surface of one (or both) of the core wrap layers and the absorbent material to reduce leakage of SAP outside the core wrap. Also, as described in the above-mentioned Hundorf reference, a microfibrous adhesive net may be used in the airfelt-free core. These adhesives are not shown in the figures for simplicity. Other core structures including a high-loft nonwoven substrate, such as a carded nonwoven layer, having a porous structure on which SAP particles are deposited may also be used in the present disclosure. Such high-loft cores are disclosed, for example, in Chinese Patent No. 101797201, International Publication No. 2016106021, and U.S. Patent Application No. 17 / 542592. The high-loft central layer typically has superabsorbent polymer particles (60) blended with the fibers of the central layer and is a nonwoven fabric having a density of less than 0.200 g / cc, specifically measured at a pressure of 4.14 kPa. The central layer can be, for example, a high-loft carded nonwoven layer.

[0037] The basis weight of the absorbent material (the amount deposited per unit of surface) can be varied, particularly in the longitudinal direction but also in the transverse direction of the core, or in both directions, to create a profile distribution of the absorbent material to provide more absorbency towards the center and the middle of the core.

[0038] The absorbent material layer may include one or more channel-forming areas. A channel-forming area is an area that substantially does not contain, and specifically does not completely contain, the absorbent material (any incidental trace amounts of absorbent material due to accidental contamination of the channels by the high speed of the manufacturing process are ignored). The channel-forming area, if present, may include a channel bond between the upper side and the bottom side of the core wrap. This bond provides the structural integrity of the channels in both the dry and wet states. To provide this bond, any known bonding technique known in the art may be used, specifically, hot melt adhesive bonding may be used for the channel bond. The adhesive may be applied, for example, typically by slot gluing or any other means, within the channel areas on the inner side of the upper side and / or the inner side of the bottom of the core wrap, and then pressure is applied to the channel areas to provide a good adhesive bond in these areas. Exemplary patent disclosures of such adhesive bonding processes can be found in International Publication No. WO 2012 / 170,798 (A1) (Jackels et al.), European Patent No. 2,905,000 (Jackels et al.) and European Patent No. 2,905,001 (Armthold-Osmol et al.) for airfelt or airfelt-free absorbent cores.

[0039] Inner cuff 34 and outer cuff 32 Absorbent article 20 is known in the art and may include a pair of barrier leg cuffs 34 (also referred to as inner cuffs) and a pair of gasket elastic cuffs 32 (also referred to as outer cuffs), as briefly described herein. The barrier leg cuffs 34 are positioned laterally inward of the gasket cuffs 32 and can extend vertically away from the side facing the wearer of the article, as shown in FIG. 5. For this reason, the barrier leg cuff 34 is bounded by a proximal edge 35 directly or indirectly joined to the topsheet and / or backsheet and a free end edge 37 intended to contact the wearer's skin and form a seal with the skin. The barrier leg cuff 34 typically extends partially between a front edge 10 and a rear edge 12 disposed in pairs on both sides of the central longitudinal axis 80 and is present at least at the level of point M. The barrier leg cuff 34 can preferably include one or more elastic strands 33 near or at the free end edge 37. These elastic strands 33 cause the barrier leg cuff 34 to form a seal around the wearer's legs and torso. The barrier leg cuff 34 does not extend toward the front and rear edges of the article 20. Rather, the cuff material 36 is flatly attached (adhesive bonding is not shown for clarity of the figure) to the chassis of the article (typically on the topsheet) in the front and rear regions, as illustrated in FIGS. 4 and 6.

[0040] The gasket elastic cuff 32 is elasticized and preferably includes one or more elastic strands 31 sandwiched between the backsheet 25 and the barrier cuff material 36, extends at least partially between the front edge 10 and the rear edge 12 of the article, and is present at least at the level of point M. The elastic body 31 of the gasket cuff essentially forms a seal around the wearer's leg at the portion of the absorbent article proximate to the chassis side edges 13, 14.

[0041] Both the inner cuff 34 and the outer cuff 32 may be formed of a cuff material piece 36, typically a nonwoven fabric such as SMS, and the cuff material piece 36 is partially joined to the chassis of the absorbent article 20 from the longitudinal edges 13, 14 to the proximal edge 35 of the cuff, so that the barrier leg cuff 34 extends upward from the surface facing the wearer of the absorbent article 20 and can provide improved containment of body excretions near the junction of the wearer's torso and legs.

[0042] Landing zone 44 Referring to FIGS. 1 and 3, the absorbent article 20 in the form of a taped diaper may typically have a separate material forming a landing zone 44 disposed adjacent to the front edge 10 of the article 20 on the side facing its clothing. The landing zone 44 is configured to receive the fastener 42 and may include, for example, a plurality of loops configured to engage a plurality of hooks on the fastener, or vice versa.

[0043] The landing zone 44 typically includes a nonwoven material attached to a portion of the outer cover 25b of the backsheet adjacent to the front waist edge 10 of the taped article. If the outer cover material has sufficient loft or other necessary properties to interact sufficiently with the fastener 42, some outer cover backsheet materials 25b may alternatively function directly as the landing zone without the need for a separate landing zone strip 44. When the landing zone 44 exists as a separate piece of material attached to the backsheet as shown in the figure, the landing zone 44 is preferably disposed under the front waistband 100. In other words, the front waistband 100 is preferably disposed between the landing zone 44 and the front edge 10 of the article. The waistband 100 may be directly adjacent (i.e., less than 1 cm away from the front edge 10 of the article, and the landing zone 44 is still adjacent to the front edge (i.e., less than 5 cm away), but the front waistband may be disposed therebetween.

[0044] Front waistband 100 and rear waistband 200 The front waistband and the rear waistband can be made from any elastic material suitable for incorporation into absorbent articles such as diapers known in the art. However, the elastic strength of the waistband is selected to meet the requirements of the present invention.

[0045] Typical waistband structures 100, 200 include a plurality of elastic strands 110, 210 adhered and laminated between two nonwoven substrates. The elastic force of the waistband can be adjusted by varying the elastic strength of the individual strands (typically, the thicker the strands, the higher the strength when measured by their dtex value) and the number of strands (the greater the number of strands, the higher the elastic force achieved).

[0046] A simplified process for continuously and simultaneously making the front and rear waistbands as a nonwoven laminate having elastic strands is illustrated in FIGS. 7a - 7d. A continuous supply of waistband material 70 is provided in the machine direction MD, for example, by unwinding a web of suitable material. Suitable waistband materials are, for example, low basis weight nonwovens such as SMS materials (e.g., having a basis weight of 8 gsm - 20 gsm). The web may advantageously have a width approximately twice that of the desired combined front and rear waistbands, and have a first half 71 and a second half 72 extending in the MD, which are of equal width and are conceptually divided by a fold line 73.

[0047] The elastic strands 110, 210 are continuously provided from a suitable number of spools (not shown), as is known in the art. The elastic strands 110 and 210 can be of the same elastomeric material, but advantageously, the strand 110 for the front waistband 100 has a smaller dtex value and a smaller number than the strand 210 of the rear waistband 200. Adhesive is typically applied intermittently to the strands through a nozzle (not shown). For this reason, a part of the elastic strand is free of applied glue. The elastic strands 110, 210 are superimposed on the waistband material 70 on the first half 71 of the waistband material. A person skilled in the art will understand that the process is continuous and that the waistband material 70 and the elastic strands 110, 210 are unwound from rolls and / or spools of raw material and aligned parallel to each other at high speed in the machine direction, as shown in FIG. 7a.

[0048] In a second step, illustrated in FIG. 7b, the second half 72 of the waistband material 70 is folded by a folding plate (not shown) along the folding line 73 over the first half 71. For this reason, this second step provides a laminate comprising elastic strands sandwiched between two nonwoven layers formed by the folded nonwoven material web 70. The laminate can be passed between two rolls to help the adhesive provide integrity to the laminate. The continuous waistband laminate 74 thus obtained comprises elastic strands 110, 210 sandwiched between two nonwoven layers formed by the folded waistband material 70. For this reason, the continuous waistband laminate displays an adhesive bonding region 75 separated by a non-bonding region 76. The elastic strands are adhesively attached to the waistband material in the bonding region 75.

[0049] The continuous laminate 74 is cut in the machine cross direction along the dashed cut line 77 in the non-bonded region 76 (FIG. 7c). These dashed cut lines cut the elastic strands but only partially cut the waistband material (typically, a non-woven fabric). The elastic strands snap back from the intermittent area 76 where the glue is not applied, but the waistband material 70 remains partially connected by the dashed cut process.

[0050] In a further step (not shown), the waistband laminate 74 is aligned with the transverse direction of the chassis of the article and, if necessary, the laminate structure is optionally rotated through a 90-degree rotating roll. The laminate is also broken along the dashed cut line 77 and stretched to form the combined pad 78. This combined pad 78 can then be cut along the cut line 79 in another step (FIG. 7d) to separate the pad into a front waistband laminate 100 and a rear waistband laminate 200 that can be attached to the chassis of the article. This illustrated process extends simultaneously on the deformation line while the remainder of the chassis of the article is being made.

[0051] However, other elastication waistband manufacturing processes and still other types of elastic waistbands can also be used in the present invention. For example, an alternative but more expensive method for elastifying a waistband is to use an elastomeric film laminated between two non-woven substrates, which can be made outside the line and then transported as a roll of material, as is known in the art. Thus, while the process described above is preferred, it does not limit the articles of the present invention as defined by the characteristics of the waistband.

[0052] According to the present invention, it has been found that the front waistband elastic force should be in the range of about 0.03 N to about 0.32 N. The rear elastic waistband should have a rear waistband elastic force higher than the front waistband elastic force. The rear waistband elastic force can specifically be in the range of 1.1 N to about 2.9 N. The front and rear waistband elastic forces are measured as shown by the measuring method further described below.

[0053] The ratio of the value of the rear waistband elastic force to the value of the front waistband elastic force (the value obtained by dividing the rear waistband elastic force by the front waistband elastic force) can advantageously be in the range of 4 to 40, specifically in the range of 5 to 30.

[0054] The different elastic forces for the front waistband and the rear waistband can be obtained from the same type of elastomeric material (e.g., elastane strands) by providing more elastic strands and / or strands with a higher dtex value in the rear waistband than in the elastic strands in the front waistband.

[0055] The elongation of the front waistband 120 and the elongation of the rear waistband 220 can typically be substantially the same (typically corresponding to the length of the nonwoven material forming the outer layer of the elastic laminate). This is especially the case when the waistbands are made simultaneously from the same starting waistband material 70, as illustrated in FIGS. 7a - 7d. The width w2 of the rear waistband may typically be larger than the width w1 of the front waistband because it contains more elastic strands, and there may be more space adjacent to the rear edge 12 of the article than adjacent to the front edge 10 of the article due to the presence of a landing at the front of the article.

[0056] The effective adhesive elastic length (E.G.E.L. in FIG. 8) of each of the front waistband and the rear waistband (measured as shown in the following waistband force measurement method) should be long enough for the chassis of the diaper to provide an elastic force that continuously extends around the wearer's waist. The rear waistband may advantageously have an effective adhesive elastic length within the range of 50% to 100% (specifically, 70% to 95%) of the length W of the trailing edge 12 of the absorbent article (see FIG. 2). Similarly, the front waistband may advantageously have an effective adhesive elastic length within the range of 50% to 100% (specifically, 70% to 95%) of the length W of the leading edge 10.

[0057] Other components The topsheet 24, the backsheet 25, the absorbent core 28, the front waistband and the rear waistband 100, 200, and other components of the article can be assembled into various known configurations, specifically by gluing, fusing, and / or pressure bonding. The absorbent article of the present invention may include any typical layers and components used in diaper-type absorbent products and are not necessarily represented in the simplified FIGS. 1 to 6. A more detailed disclosure of examples of such components is disclosed, for example, in International Publication No. WO 2014 / 093323, International Publication No. WO 2015 / 183669 (both by Bianchi et al.), International Publication No. WO 2015 / 031225 (by Roe et al.) or International Publication No. WO 2016 / 133712 (by Ehrnsperger et al.).

[0058] For example, an absorbent article may include at least one capture layer between the topsheet 24 and the absorbent core 28, as is common in the art. Since the secondary layer has a similar function, the capture layer may not be necessary if the article includes a bilayer topsheet laminate, as represented in the figures for the absorbent article. The capture layer is typically a nonwoven fabric such as an airlaid bonded carded nonwoven fabric and may be hydrophilized. The distribution layer also specifically includes or consists of relatively loose fibers with no or weak fiber bonding within the fibers and may be present when disposed between the capture layer and the absorbent core. A typical example of a distribution material includes or consists of crosslinked cellulose fibers. Examples of chemically crosslinked cellulose fibers that have been used to make the distribution layer are disclosed in U.S. Patent No. 5,549,791, U.S. Patent No. 5,137,537, International Publication No. 95 / 34329, or U.S. Patent Application Publication No. 2007 / 118087. This type of material has been used in disposable diapers in the past, for example, as part of the capture distribution system of U.S. Patent Application Publication No. 2008 / 0312622(A1) (Hundorf).

[0059] The topsheet 24, the backsheet 25, and the absorbent core 28 may be assembled in various known configurations, specifically by gluing, heat embossing, ultrasonic bonding, or combinations thereof. Exemplary diaper configurations are outlined in U.S. Patent No. 3,860,003, U.S. Patent No. 5,221,274, U.S. Patent No. 5,554,145, U.S. Patent No. 5,569,234, U.S. Patent No. 5,580,411, and U.S. Patent No. 6,004,306.

[0060] Bio-based materials Any component of the absorbent article of the present invention can be at least partially composed of bio-based content as described in US Patent Application Publication No. 2007 / 0219521 (A1), US Patent Application Publication No. 2011 / 0139658 (A1), US Patent Application Publication No. 2011 / 0139657 (A1), US Patent Application Publication No. 2011 / 0152812 (A1), US Patent Application Publication No. 2011 / 0139662 (A1), and US Patent Application Publication No. 2011 / 0139659 (A1). These components include, but are not limited to, topsheet nonwoven fabric, backsheet film, backsheet nonwoven fabric, barrier leg cuff nonwoven fabric, superabsorbent material, upper and lower core wrap layers, adhesive, fastening hook, and fastening landing zone nonwoven fabric, and film base.

[0061] The components of the disposable absorbent article can have a bio-based content value of about 10% to about 100%, in another embodiment, about 25% to about 75%, and in yet another embodiment, about 50% to about 60% using Method B of ASTM D6866-10.

[0062] To determine the bio-based content of the components of any disposable absorbent article by applying the methodology of ASTM D6866-10, a representative sample of the components of the disposable absorbent article needs to be obtained for testing. Thus, the components of the disposable absorbent article can be ground into particles less than about 20 mesh using a known grinding method (e.g., Wiley® mill), and a suitable mass of representative sample can be taken from the randomly mixed particles.

Example

[0063] An absorbent article suitable as a size 4 diaper for infants, generally illustrated in FIGS. 1 to 6, was produced with the following dimensions.

[0064]

Table 1

[0065] The rear waistband 200 included 11 elastane elastic strands each having 620 dtex, and the front waistband 100 included 3 elastane elastic strands each having 470 dtex. The front waistband had an elastic force of 0.1 N (measured by the method shown below), and the rear waistband had an elastic force of 1.98 N. The absorbent core was a high-loft absorbent core as described above.

[0066] Comparison data Four types of tape diapers having different elastic forces of the front and rear waistbands were tested in a consumer fit study (N = 28 or 12 infants). A further control diaper having only a rear waistband and no front waistband was tested. For each diaper, the accompanying parent was asked to rate the fit of the front waist of the diaper as tight, just right, or loose.

[0067] The results are as shown in Table 2 below.

[0068]

Table 2

[0069] Of all the diapers tested, the diapers having a front elastic waistband force of 0.10 N were found to have the highest consumer fit rating (100% just right) as shown in Table 2 above.

[0070] Although not wishing to be bound by theory, the inventors believe that higher front waistband elastic forces lead to a higher loose fit as the front waist edge of the diaper falls to a fixed position (considerably below the baby's navel). This causes the diaper to sag and reduces the fit of the diaper. Further, if the front waistband is too tight (strong force), this causes a lot of wrinkles in the front and causes the consumer to stretch the front waist portion several times. This adds additional application effort and increases the inconvenience of application. However, if the front waistband force is too low, there is no advantage in preventing fluid leakage compared to a product without a front elastic waistband.

[0071] Test method Method for measuring waistband elastic force This method measures the waistband elastic force of the front elastic waistband and the rear elastic waistband of a taped absorbent article at 85% of the effective pasted elastic length (Lread) after stretching twice at the maximum stretch length (Lmax). This method is carried out in a climate-controlled room at a standard state of 23°C ± 2°C.

[0072] Definition Effective pasted elastic length (EGEL): In the case of a waistband having one or more elastic strands, this is the minimum distance between the ends of the individual elastic strands at the position where the individual elastic strands begin to contract, as illustrated by the distance E.G.E.L. for exemplary rear waistbands 100, 200 in FIGS. 8a - 8b (the same principle applies to the front waistband). In the case of an elastic waistband without elastic strands, such as a stretch laminate including an elastic film, the effective pasted elastic length is measured at the position of the first wrinkle on each side of the waistband. In practice, E.G.E.L. can be most easily measured by taking the known total length 120, 220 of the waistband material (relaxed state) and subtracting the lengths of the lateral non-bonded zones D1, D2 measured directly on the waistband.

[0073] Maximum elongation length Lmax: 95% of the effective pasting elastic length of the waistband (Lmax = 0.95 × EGEL).

[0074] Length Lread at the reading point: 85% of the effective pasting elastic length (Lread = 0.85 * EGEL).

[0075] Sample preparation: 1. Take out the diaper product from the package, open the product with the top sheet facing the operator, and do not stretch the waistband part. 2. Along the edge of the waistband, configure a cutting guide line parallel to the transverse axis of the product. 3. Using scissors / cutter, cut the waistband along the configured line so that the waistband is separated from the chassis. Do not cut or break any elastic body or non-woven fabric where the elastic body is located. If this happens, take out a new pad and start over. 4. If any SAP exposure is observed, use masking tape to tape up the exposed edge and ensure that the tape does not restrain any material. 5. As shown in the above definition, draw a pair of reference lines (perpendicular to the length of the waistband) for each end of the effective pasting elastic length.

[0076] Device: The measuring instrument 91 is illustrated in FIGS. 9a to 9b and includes a lower clamp 92 and an upper clamp 93. The lower clamp 92 is slidable, so the distance d between the upper clamp bar line 92' and the lower clamp bar line 93' can be adjusted manually.

[0077] Force stand: A force gauge with stand / model E-DFE-002, manufacturer: Trimborn + Guld Maschinenbau GmbH, a digital force gauge with a minimum resolution of 0.01 N, 0 - 10 N (Newton) scale, or equivalent (reference number 94).

[0078] Clamp: A convenient supply source. A clamp wide enough to hold the waistband strip.

[0079] Scissors: A convenient supply source.

[0080] Marker: For example, a ballpoint pen.

[0081] Ruler: A metal ruler longer than the length to be measured, marked in mm, compliant with NIST, DIN, JIS, CMC or other equivalent national standards.

[0082] Timer: A convenient supply source.

[0083] Mask: A convenient supply source for AGM.

[0084] Tape: A convenient supply source.

[0085] Equipment preparation: The force stand 91 is adjusted according to the following steps (Figs. 9c - 9d): 1. Move the lower clamp 92 to the lowest position. 2. Move and fix the lower clamp so that the distance d between the upper width clamp bar line and the lower width clamp bar line is L max (Fig. 9c). 3. Move the lower clamp to the arm stop 95 and adjust / fix the arm stop so that the distance d between the upper clamp bar line 93’ and the lower clamp bar line 92’ is L read (Fig. 9d).

[0086] Test procedure (Figs. 10a - 10e): 1. Position the lower clamp at its upper position (relaxed position). 2. Attach the waistband strip perpendicularly to the clamp by clipping one end of the waistband strip, along with all the elastic ends, to the upper clamp 93 so that the marked reference line (step 5 of sample preparation) aligns exactly with the width clamp bar line 93’. Ensure that the sample does not slip from the clamp point. 3. Place the clamp centered directly above the sample. 4. Reset the force gauge when the sample strip is attached within the upper clamp. 5. Clip the other end of the sample strip with all the elastic ends to the lower clamp 92 as described in step 2 so that the second marked reference line coincides with the lower clamp line 92’. Ensure that the sample strip is in its fully relaxed position (Figure 10a). During execution, do not stretch the sample strip. Ensure that the sample is not twisted and does not slip from the clamp point. 6. As the first step, extend the sample strip: This is done by moving the lower clamp 92 to the bottom position (LMax). By doing this, the sample strip extends to the “maximum extension” point (Figure 10b). After leaving it there for approximately 1 second, then return the sample strip to its fully relaxed position (Figure 10c). 7. Extend the sample strip a second time to the LMax distance (Figure 10d) and hold it there for approximately 1 second. 8. Swing / slide the stop arm 95 (set to be the “reading point” during the “equipment preparation” stage) and slowly raise (at approximately 3 - 5 cm / second) the lower clamp 92 relative to this “reading point” plate stop arm (Figure 10e). 9. Wait approximately 5 seconds until the value on the gauge stabilizes and read the value from the display. Record the value in the nearest 0.01 N unit.

[0087] Note: If sample slippage from the clamp occurs during measurement, repeat the test for data reading. The lower clamp 92 is manually moved at a speed of approximately 10 - 15 cm / second in the above steps unless otherwise instructed.

[0088] Report: Report the determined value to the nearest 0.01 N.

[0089] Others As used herein, the terms "comprise(s)" and "comprising" are open-ended. Each specifies the presence of the subsequently recited features, e.g., elements, but does not exclude the presence of other features, e.g., elements known in the art or disclosed herein. These terms based on the verb "comprise" are to be construed as encompassing the more restrictive terms "consisting essentially of", which excludes any element, step, or ingredient not recited that significantly affects the way the feature performs its function, and "consisting of", which excludes any element, step, or ingredient not specified. None of the preferred or exemplary embodiments described below limit the claims, unless specifically stated otherwise. Words such as "typically", "usually", "preferably", "advantageously", "specifically", etc. also modify features not intended to limit the claims, unless specifically shown to the contrary. The dimensions and values disclosed herein are not to be understood as strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and the functionally equivalent range surrounding that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".

[0090] All documents cited herein, including any patents or patent applications that are cross-referenced or related, and any patent applications or patents for which this application claims priority or the benefit thereof, are incorporated herein by reference in their entirety to the extent not expressly excluded or limited. The citation of any document is not to be construed as an admission that it is prior art with respect to any invention disclosed or claimed herein, or that it alone, or in combination with any other reference or references, teaches, suggests, or discloses any such invention. Further, any meaning or definition of a term in this document that conflicts with any meaning or definition of the same term in a document incorporated by reference shall be determined by the meaning or definition given to the term in this document.

[0091] Although specific embodiments of the invention have been illustrated and described, it will be apparent 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. Accordingly, it is intended that all such changes and modifications within the scope of the invention be covered by the appended claims.

Claims

Claim 1 A tape - type absorbent article (20) having a front half region (15) with a front waist edge portion (10), a rear half region (16) with a rear waist edge portion (12), a first longitudinal edge portion (13), a second longitudinal edge portion (14), a side facing the wearer, and a side facing the clothing, wherein the tape - type absorbent article comprises: - A topsheet (24) on the side facing the wearer thereof; - A backsheet (26) on the side facing the clothing thereof; - An absorbent core (28) between the topsheet and the backsheet; - A pair of rear ear portions (40) in the rear half region, each rear ear portion having a fastening tab (42) that can be removably attached to a landing zone (44) on the side of the tape - type absorbent article facing the clothing in the front half region of the tape - type absorbent article; - A front elastic waistband (100) adjacent to the front waist edge portion (10), having a front waistband elastic force that is in the range of 0.03 N to 0.32 N when measured by the waistband elastic force measurement method disclosed herein; - A rear elastic waistband (200) adjacent to the rear waist edge portion (12) of the tape - type absorbent article, the rear elastic waistband having a rear waistband elastic force that is higher than the front waistband elastic force, and comprising: The rear waistband elastic force is in the range of 1.1 N to 2.9 N; A tape - type absorbent article (20) in which the ratio of the rear waistband elastic force to the front waistband elastic force is in the range of 4 to 40. Claim 2 The tape - type absorbent article (20) according to claim 1, wherein the front elastic waistband and the rear elastic waistband each comprise a plurality of elastic strands (110, 210). Claim 3 The tape - type absorbent article according to claim 2, wherein the elastic strands of the rear elastic waistband have a greater number and / or a higher dtex value than the elastic strands of the front elastic waistband. Claim 4 The tape - type absorbent article according to claim 2 or 3, wherein each of the elastic strands of the front elastic waistband and the rear elastic waistband is sandwiched by a non - woven waistband material. Claim 5 The tape-type absorbent article according to claim 1, wherein the front elastic waistband is disposed between the landing zone and the front edge of the tape-type absorbent article.

6. The tape-type absorbent article according to claim 1, wherein the rear elastic waistband has an effective pasting elastic length (220) within a range of 50% to 100% of the length (W) of the rear edge (12) of the tape-type absorbent article, and / or the front elastic waistband has an effective pasting elastic length within a range of 50% to 100% of the length of the front edge (10) of the tape-type absorbent article.

7. The tape-type absorbent article according to claim 1, wherein the absorbent core includes a high-loft nonwoven center layer within a core wrap, and superabsorbent polymer particles are at least partially immobilized within pores of the high-loft nonwoven center layer.

8. The tape-type absorbent article according to claim 1, comprising a double-layer top sheet having a primary three-dimensional top sheet layer (24a) laminated on a larger secondary nonwoven top sheet layer (24b).

9. The tape-type absorbent article according to claim 1, comprising a renewable or recyclable material.

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