Patent Application
20250213397
The present invention relates to a reusable hygiene article chassis comprising a pocket for receiving a replaceable absorbent pad. The chassis comprises a liquid intake zone which is particularly adapted to receive bodily exudates and further transfer these to the absorbent pad.
Apart from washable cloth diapers, two-piece diaper systems comprising a reusable and washable outer layer and a disposable insert have long been used. Over the last decades, disposable diapers have significantly improved both ease of application and liquid handling performance, which further led to healthier skin of a wearer even at extended wear times, not only for babies but also for incontinent adults as well as for menstruating women. Especially for the latter two categories, absorbent pads are broadly used for lower liquid handling requirements, such as light to medium incontinence or lower menstrual flow conditions, whereby such pads are typically inserted into regular underwear, optionally attached thereto by releasable adhesive, or—mostly in hospitals or care facilities—elasticated pants. In particular for mobile people, discreetness during wear times and ease of replacement become highly relevant. However, with an increased environmental awareness, disposable products have come under scrutiny for using non-renewable resources and/or for an increase carbon footprint in the overall lifecycle, including treatment of the used products.
It is also known to design products in particular for menstrual products or very light incontinence products, being washable with a slightly increased absorbent capacity in the crotch region so as to accommodate small amounts of exudates. Such products may comprise a hydrophilic wad of fibers in the crotch region, optionally in combination with a thin protective coating or film to reduce the risk of soiling of the clothing. Such products may be laundered and reused many times, and as such also allow the use of more expensive materials, such as textile extensible materials, such as knitted cotton, as well known from conventional underwear, or elastic materials, such as rubber, preferably synthetic rubber, or synthetic elastic materials, known as LYCRA™ and the like.
However, the use of such products is limited for several reasons: First, de facto the product has to be washed, at least coarsely rinsed, and dried just after being used. Otherwise, if left wet, not only unpleasant smell may develop upon wet storage, but also bacteria may develop, that will require even harsher washing conditions. To avoid bacterial growth, it is quite common to use textiles treated with biocides for such washable products having the downside of potentially having a negative impact on skin health by destroying the natural bacterial climate of the skin.
Furthermore, biocides also have a negative impact on the environment if they partly get washed off during washing of the product or after disposal.
Further, other additives that are susceptible to be removed during washing, or a least reduced in their efficiency, such as the mentioned bacterial growth inhibitors, or odor reducing agents, or odor masking agents, cannot be employed effectively. This is particularly relevant for superabsorbent materials, as are well-known for increasing the absorbent capacity beyond the one of the hydrophilic waddings, which should not exhibit high liquid absorbency, as otherwise also the drying may become inefficient. Such superabsorbent materials not only dry very slowly but may even lose their absorbency properties upon washing.
Even further, at away-from-home activities, the same difficulties for changing a product arise as described for one-piece articles in the above, further aggravated by the need to stash the loaded product away until being home again.
Also, with regard to environmental compatibility, the re-usable and washable products require an increased use of energy (e.g., for operating equipment, heating laundry water, and treating wastewater) and chemicals (e.g., detergents and water treatment agents), such that a comparison of washable and fully disposable products with regard to “environmental compatibility” is complicated, and undisputed conclusions either way do not yet appear to exist.
In view of the concerns set forth above, it would be advantageous if a wearable absorbent article were available that provides advantages afforded by both disposable and reusable diapers, while reducing the respective disadvantages of these alternatives. It also would be advantageous if a construction were provided that could simplify manufacturing processes and/or reduce costs.
Henceforth several approaches are known to improve usefulness, costs, and environmental compatibility with systems that combine a more efficient disposable absorbent core with a functional reusable chassis.
U.S. Pat. No. 6,142,983 discloses a disposable absorbent article with an outer cover, an absorbent chassis and an absorbent support member which is configured to maintain the absorbent chassis in close contact with the wearer's body in use. US20060247599 refers to an absorbent garment having a garment-like outer shell and an absorbent assembly positioned therein. WO1995010992A1 discloses a diaper assembly including a washable over-garment and a reusable moisture proof sheet positioned on the inner surface side of the garment.
U.S. Pat. No. 3,489,149 (Larson) describes a re-usable and washable panty for menstrual wear having in the crotch portion a pocket for an optional absorbent insert or pad, wherein the user-oriented portion of the pocket is formed from a first hydrophobic, yet moisture-passing layer for improved skin dryness oriented towards the wearer and a hydrophilic layer oriented towards the insert, if present, or the panty material, which has some tendency to retain moisture for the case when not used in combination with an insert pad. The insert may be disposable.
US2021/0100698 (P&G, Langdon) describes a unitary or two-piece article, wherein the chassis portions exhibit particular stretch properties so as to allow good adaptation to body contours, especially in the crotch region.
In EP2376046, a wearable absorbent article to be worn by a wearer about the lower torso is described, comprising a re-useable chassis adapted to receive an absorbent insert therein. The chassis comprises insert fastener components and the absorbent insert comprises a pair of elasticized standing cuffs.
Along these developments, the commercially available PAMPERS™ Hybrid design provides baby diapers with a reusable chassis and a disposable absorbent core—just as at the beginning of diapering, but with more modern materials, especially superabsorbent materials.
Co-pending application EP22164271 (Pelz, unpublished) describes a system with an article chassis that is adapted to receive an absorbent core on its outer surface, so as to ease replacing of the core upon loading, addressing improved positioning but also exchange of a loaded absorbent core.
However, these current approaches fall short of a balancing user friendliness, functionality and minimizing the amount of disposed material. Fully disposable articles may satisfy user friendliness and functionality very well, but do not address the increased dislike versus waste generation. Also, customization, i.e., adapting properties of an article to differing requirements or preferences of a user, is difficult to satisfy with such articles as the choice of materials used to design the product is restricted by material cost which needs to be limited for disposable products.
Fully reusable—hence washable—systems have either very limited absorbent capacity or require high amounts of absorbent material, contributing to bulkiness and discomfort. Furthermore, the choice of materials is limited to materials suitable for the washing step. Especially superabsorbent materials as well as additives controlling pH for skin-friendliness and odor controlling/absorbing additives are mostly not compatible to the washing process due to their interaction with water and detergents.
The present invention addresses the need for products that satisfy the desire for minimal disposable material together with good performance even at higher liquid loads and with customizable properties and functionalities that are incompatible with washing requirements.
In a first aspect, the present invention is re-usable article chassis for being worn on the lower torso of a wearer, and in a second aspect a hygiene article system, comprising such a re-usable article chassis and an absorbent pad.
The article chassis exhibits a user-oriented surface and an opposite outer surface, and comprises at least one liquid intake zone adapted to cover a region of the exudate releasing body openings, comprising chassis fluid handling aid material, which exhibits, when tested on the surface adapted to be oriented towards the user
The article further comprises a main chassis region preferably circumscribing the at least one liquid intake zone and optionally a transition region, connecting the intake zone and the main chassis region, and optionally a topsheet material covering the intake zone. The article comprises at least one pocket covering at least a portion of the at least one intake zone, comprising a pocket opening adapted for receiving and positioning an absorbent pad in liquid contact with the liquid intake zone. The pocket may be accessible for a user in a pre-use configuration and in an in-use configuration.
Optionally, the main chassis, the intake zone(s) and the transition region, if present, consist essentially of materials and construction elements that are washable at at least 40° C., preferably at at least 60° C., more preferably at at least 90° C. for at least 30 times, preferably at least 60 times. A re-usable article chassis may further comprise one or more elements selected from the group consisting of
In the second aspect, the present invention is a hygiene article system, which comprises such a re-usable article chassis and an absorbent pad, which comprises
Such a hygiene article system may further comprise a handling aid for easing application and/or removal of the absorbent pad, as may be a stiffening member, adapted to be used for multiple applications of absorbent pads. Alternatively or additionally, the handling aid may be integral with the absorbent pad and preferably comprises one or more elements selected from the group consisting of
The absorbent pad of a hygiene article system may further comprise one or more of the elements selected from the group consisting of
The absorbent pad may further exhibit one or more features selected from the group consisting of
Preferably, the absorbent pad exhibits a size smaller than the fluid intake zone of the article chassis, preferably covering less than 90%, preferably less than 70%, more preferably less than 50% of the fluid intake zone, optionally having a liquid permeable lower core cover sheet material.
The hygiene article chassis may comprise a chassis fluid handling aid material, positioned
Also, the hygiene article chassis may comprise
The figures are schematically only, and not to scale. Same numerals refer to same or equivalent features or elements, single (') or multiple (“, '”, . . . ) apostrophes indicate duplicate features, such a left and right or front and back, etc.
Within the present context, absorbent hygiene articles are intended to be worn on the lower torso of a human wearer of any age, adapted to receive bodily exudates, especially liquid exudates, such as urine, menses, as are released in the vaginal region, or from the penis, towards the “intake zone” of the article positioned adjacent to the exudate releasing organ.
Generally, absorbent hygiene articles comprise an “absorbent core” for handling the bodily fluids, i.e., acquiring, distributing and storing these therein, and a “chassis” for holding the absorbent core in place on the body of a wearer. Absorbent articles may be donned and doffed by the user him- or herself, or by a care-taker, such as a parent for babies.
Hygiene articles can be classified as
In order to adapt to the complex body contours, the chassis often exhibit “elasticity”, such as induced by elastic elements like rubber, preferably synthetic rubber, strands, including LYCRA™ or similar, but also elastomeric polyolefins, as in films or non-woven. In addition, or alternatively, the chassis may comprise structurally “extensible” materials, such as well-known e.g., from knitted cotton underwear, wherein the knitted yarns are essentially non-elastic, but the knitted structure can readily conform to the body contours, albeit at retractive forces that are typically lower than for elastic materials.
An “absorbent pad” generally consists of an absorbent core between an upper, user-oriented coversheet and a lower, oppositely positioned lower coversheet, and may be held in place on the body by other means, such as a specially adapted removable chassis, or regular underwear, optionally aided by non-permanent adhesives and/or “wings” as may be folded around the crotch portion of the underwear.
The term “permanent” refers to a feature that remains essentially unchanged during the intended use, and as such may be a connection, that can only be disconnected destructively, or a treatment, such as a hydrophobization, that remains during the intended uses, although its effect may be reduced.
A “single piece diaper” comprises an “absorbent core” firmly and permanently connected to a “chassis” by which the absorbent core is held in place on the body of the wearer.
For “two-piece systems”, the absorbent core in an absorbent pad and the chassis are separate or at least can be readily separated, though “pre-combined systems”, where the manufacturer combines the core and chassis removably, may be used. The absorbent core may be in a “replaceable” absorbent pad as can be readily removed and for which a like component or a component providing similar or different functionality can be substituted. The chassis may be similar to the underwear, as well known e.g., from hospital “net-pants” holding any absorbent pad more or less accurately in place. The present invention is directed to such a two-piece system.
The chassis of the absorbent hygiene articles comprise an “inner” or “wearer facing layer”, forming the innermost surface which may be in direct contact with the skin during use, typically formed by a skin contact sheet or “topsheet”, but may also include other elements such as (single or multiple) leakage barrier cuffs or inwardly positioned chassis layers in the waist or hip regions. The absorbent hygiene article also comprises an “opposite” or “garment facing layer”, with elements of the chassis that form the outer surface of the absorbent article, such as the backsheet, the side panels, the waist fasteners, and the like, when present. Within the present context the terms “upper”/“inner” and “lower”/“outer” correspond to “towards the user” and “away from the user”, respectively. The term “major surface” describes surfaces of greatest extent of a generally planar or sheet-like structural element and to distinguish these surfaces from the minor surfaces of the end edges and the side edges, i.e., in an element having a length, a width, and a thickness, the thickness being the smallest of the three dimensions, the major surfaces are those defined by the length and the width and thus having the greatest extent.
Absorbent hygiene articles or elements thereof may be “disposable”, i.e., intended for a single use for being discarded, optionally recycled, in an environmentally compatible and hygienic manner.
Absorbent hygiene articles or elements thereof may be fully “re-usable”, which are adapted to be cleaned many times, typically withstanding at least 30 times, preferably at least 60 times without major deterioration of its properties and functionality, and thus withstand washing with conventional detergents, typically at at least 40° C., preferably at at least 60° C. or more, and even more preferably at at least 90° C. Lower temperatures may be acceptable, if particular cleaning agents are employed, or if the materials of the articles have been particularly treated, such as by permanently incorporated biocides. “Limited re-usability” refers to articles that can be cleaned multiple times, though have a higher wear than the fully re-usable ones, and/or may be discarded like disposable articles after several, e.g., up to ten, use cycles.
Examples for fully re-usable articles are so-called “menstruation pants” that exhibit a low to moderate absorbency as may be achieved by hydrophilic fibers, such as cotton fibers or yarns, at a higher basis weight in, optionally also around, the intake zone.
The above mentioned “net pants” for hospital use typically exhibit a limited re-usability, as they can withstand washing conditions, at least for a few times, but may also be discarded, e.g., if heavily soiled by faeces, and may also be torn open for ease of removal in such cases.
The elements of the present invention as well as their functioning is now explained by referring to
When describing specific properties of materials and/or of elements, reference is made to the “Test Method” section herein below, wherein the determination of the respective parameter by specific test methods is described in detail.
In a first aspect, the present invention is a re-usable article chassis, and in another one two-piece hygiene article system, or kit, 100, comprising such an article chassis and a single use absorbent pad, as exemplarily depicted in
The article chassis 1000 exhibits a width (y-) 1018 and a length (x-) 1012 direction, the first corresponding to a left-right orientation on a user, the second corresponding to a line extending form the front, i.e., navel, through the crotch to the back, i.e., small of the back, of a user. A thickness (z-) direction 1015 extends perpendicularly to both, whereby the terms “upper”/“inner” and “lower”/“outer” correspond to “towards the user” and “away from the user”, respectively.
The skilled person will readily apply such terms also to a chassis and an absorbent pad when detached from a user, such as when manufactured or packaged.
The chassis 1000 is preferably executed in a “pants style”, but may also be in an open diaper style, as indicated in
The chassis 1000 is a re-usable and washable pants shaped article, with a wearer facing inner layer 1100, which is essentially continuous but comprises a fluid intake zone 1200 and a main chassis region 1300, exhibiting a significant difference of at least one property, e.g., hydrophilicity, porosity, or rewet. As depicted in the figure, the fluid intake zone 1200 may be completely circumscribed by the main chassis region 1300, though it may extend towards the perimeter of the chassis, e.g., laterally in the crotch region. Optionally there may be a transition region 1400, see
It is important that the intake zone 1200 comprises a chassis fluid handling aid material that exhibits balanced liquid handling properties, i.e., good acquisition allowing released exudates to penetrate through and away from the wearer, as well as low rewet properties for a dry feel even after loading. Further, the chassis fluid handling aid material shall allow good liquid transfer of the loaded liquids to the absorbent pad and should not exhibit a high absorbent capacity that would detrimentally affect washing and drying. Thus, the intake zone 1200 comprises chassis fluid handling aid materials 1250, such as liquid acquisition or distribution materials, which may improve liquid uptake, but should not compromise rewet properties. Optionally, the intake zone or at least the chassis fluid handling aid material may be covered by a topsheet 1210.
The chassis 1000 comprises a pocket positioned underneath the wearer facing layer 1100 which is adapted to receive an absorbent pad 2000, whereby the application of the absorbent pad 2000 to the chassis 1000 may be made before donning of the combined chassis/absorbent pad system, but can also be readily performed after donning of the chassis without pad and/or when replacing a loaded pad. The chassis comprises a pocket opening for administering the absorbent pad, which may be positioned in the outside of the chassis allowing easy access even after donning, or inside of the chassis.
Referring to
The lower core cover sheet and the upper core cover sheet may be connected to each other along the periphery 2300 of the absorbent pad. Optionally the absorbent pad may contain further additives, especially additives that are unsuitable for being added to the chassis, such as odor absorbing or controlling materials, pH controlling materials providing a healthy skin pH or urease blocking agents for preventing release of ammonia, odor reducing or complexing agents, such as cyclodextrins, or odor masking agents, such as fragrances, or biocides or other active ingredients which are not suitable for a laundry process. It is important that the combination of the chassis 1000 and the absorbent pad 2000 is executed such that these are in good liquid contact such that good liquid transfer from the intake zone of the chassis to the absorbent pad is enabled and maintained during the full use period and preferably the chassis 1000 and the pad 2000 are adapted to each other so as to exhibiting
As exemplarily shown in
The pocket may comprise attachment elements 3260 for removably closing the pocket.
The outwardly positioned pocket materials 3220 may be liquid impermeable material, such as a plastic film which can be breathable for improved comfort, or film/nonwoven composite, or liquid repellant textiles or liquid permeable materials, depending on the liquid barrier properties of the lower core cover sheet of the absorbent pad.
The material of the pockets may be elastic, such that upon application it is stretched to then apply forces to the pad/chassis interface in the intake zone, thereby enhancing contact and improving liquid transfer, or even further enhance the body contact.
It should be noted that the fluid intake zone may have shapes and sizes that are adapted to the intended use, e.g., being designed for a female application, a male application or a non-gendered application. Accordingly, also the connection elements may be adapted. A pocket design with a slit-type opening positioned towards the front waist of a wearer, see
Having described the hygiene article system with its key elements chassis and absorbent pad in general terms and with a focus on the interaction of the elements, the following will describe particular or exemplary executions and features of these elements, still referring to the
The size and shape of chassis should be adapted to the intended use and cover the respective exudate releasing regions of the wearer, as described in the above. At least for these regions a tighter fit is preferred, like briefs, whilst outside thereof in the main chassis regions a wider fit, such as of “boxer shorts”, is acceptable.
Optionally, the chassis may comprise further leakage barriers 1500, see
The chassis should be designed to be readily and easily donned and doffed. It may be executed as a “taped system” that comprises fastening means for connecting the front and rear parts around the waist, which are preferably pre-closed during manufacturing, such that they have a pants like appearance, but are easy to be opened and re-closed, if necessary. In an often-preferred execution, the chassis is designed in a “pants style”, which encloses the waist of the wearer firmly connected like a belt, but which may include means for tearing a side seam open for easy doffing. Also, a seamless articles chassis, such as with a circular knit material, may be very suitable. Typically, such articles are stretchable or at least extensible for good fit and for easing donning.
In order to allow easy donning and also to maintain good adaptation to body contours, suitable materials may exhibit an extensibility or elasticity, of at least about 5%, preferably of more than about 10% or more than about 30% or more than about 50%, relative to the un-extended length.
Preferably, the materials exhibit a low hysteresis, so the material gets back in shape after stretching, e.g., when tested according to the tensile testing NSWP 110.4, and a low degree of “set”, so as to maintain the shape during use or avoid sagging. Preferably, retractive force are balanced so as to maintain the article in its position, even upon loading, without impacting the wearer unduly, such as red-marking would do.
The chassis may also comprise different regions of elasticity and extensibility, for example the main chassis region may exhibit extensibility as may be provided by machine knitted cotton or blends of cotton and elastic synthetic fibers. Typical blend ratios are in the range of 70% to 98% cotton and 2% to 30% elastic fibers. Instead of cotton also blends of cotton and synthetic fibers like polyester (PET) or polyamide (PA) may be used. The chassis article may further comprise an elastic waist band 1800, see
It is highly preferred that the chassis, at least the main chassis region, is “breathable” (air permeable) by exhibiting air permeability values of more than about 0.2 m3/(m2*sec), or more than about 1.0 m3/(m2*sec), when tested according to ASTM D737.18.
Suitable materials for the main chassis may be as follows, without intending to limit the selection:
Also vapor permeable film materials may be employed, which may exhibit a vapor permeability of more than 5000 (g/m2/24 h), or more than about 8000 (g/m2/24 h) or more than about 10000 (g/m2/24 h) according to “Water Vapor Transmission Rate by the Principle of Measuring the Time to Increase Humidity Lyssy/EDANA,” Part 2 NWSP 070.6.R0 (15).
Suitable chassis should be washable, i.e., withstand at least one, or at least 10, or at least 30, or at least 60 wash cycles in a conventional household washing machine, e.g., Miele WCA030 WCS-type of Miele & Cie.KG, Germany, at at least 40° C., preferably 60° C., more preferably 90° C. and 1400 rpm spinning speed. Preferably, suitable chassis should be dryer or tumbler compatible, at least under “gentle drying” conditions. Optionally, the chassis materials may be treated to reduce bacteria or odor generating effects.
In the intake zone 1200, the properties should preferably differ from the ones in the main chassis region in at least one property, preferably more than one, that is relevant for liquid handling, which may be selected from the group consisting of
As particular examples, the intake zone may be made by modification of the main chassis material, such as by applying a particular treatment, such as a hydrophobization and/or perforation or a hydrophilization in case of a hydrophobic chassis material, or may be a different material connected in a transition zone 1400 to the main chassis material by conventional means, such as without limitation stitching, gluing, and thermobonding.
The intake zone 1200 should exhibit balanced fluid handling properties of allowing quick acquisition of fluid, but also quick and effective fluid transfer to the absorbent pad 2200. Thus, the materials comprised in the intake zone, especially the intake zone topsheet may exhibit one or more of the following properties:
A particularly suitable exemplary topsheet material is a 92% polyester/8% Elastane wale/flat knitted web at a basis weight of 210 g/m2 at a thickness of 0.85 mm with fibers of approximately 18 μm diameter, available form Ruey Tay Fiber Industry Co. Ltd., Taiwan, under the designation R150411.
It is a particular feature of the present invention that the intake zone 1250 comprises a chassis fluid handling aid material 1250 which possesses particularly balanced fluid handling properties, as are suitably described by the following parameters with their respective determination methods:
Suitable materials for the intake zone may be made selected according to such requirements from a wide choice of material compositions, like nonwoven materials, such as spunbonded, carded, melt-blown webs comprising alone or blended with each other following materials:
Other suitable materials include textile webs, such as knitted, woven, or net structures, of threads or filaments as may be made from materials as also may be used for non-wovens. Also apertured films and film/textile laminates, in particular apertures films exhibiting three dimensionally shaped, funnel-like apertures, optionally combined with a fiber layer on the user-oriented side, may be used.
As indicated in
Without wishing to be limited it has been found that terry cloth fabrics may suitably satisfy such a requirement, if these are selected according to the above referenced requirements. Without wishing to be bound by the theory, it is believed that the such properties of particular terry cloth fabric stem from the combination of a lofty pile portion, which can readily acquire any fluids, and a denser base portion, enhancing liquid transport.
An exemplary suitable material is a 100% polyester base knit fabric with single sided closed loop piles, with a fiber thickness of about 11 μm, at a basis weight of approximately 260 g/m2 and a thickness of 1.7 mm, hereinafter referred to as “Terry cloth-1”, available from Ruey Tay Fibre Industry Co., Ltd, Taiwan under the trade designation 91023FM, whereby the looped side is the user-oriented side during use and testing.
Such an exemplary material has been compared to conventional materials.
A first one, dual side closed loop terry cloth, hereinafter referred to as “MyLily”, has been extracted from a commercially available menstruation pant, currently sold under High Waist—Periodenunterwäsche by MYLILY, Hamburg, Germany, and believed to be constructed from 80% polyester and 20% Nylon, advertised for an in-use capacity of up to 30 ml. For the extracted material the length orientation is maintained throughout the testing.
A second comparative material is a dual side closed loop terry cloth, with fibers at 11 μm diameter of 80% polyester and 20% Nylon, at a basis weight of 250 g/m2, and a thickness of 2.8 mm.
A comparison according to the above reference properties according to the Test Methods as described herein below gave the following results (Table 1).
Thus, the selected parameters provide an appropriate tool to distinguish inventive materials, and especially the example of Terry-cloth-1, from comparative ones.
The benefits of Terry-cloth-1 was further established by comparison with conventional market incontinence products, namely
The inventive Sample 1 was made of a composite stack in the order top to bottom of
The comparison was made according to the “intake time and rewet” test as described in the Test method section herein below with the results as shown in Table 2:
Thus, the inventive combination provides a superior combination of intake time and rewet.
Between the intake zone and the main chassis region there may be a transition region 1400, see
An example for a material used for the transition region is a Polypropylene fabric (hydrophobic) e.g., POLYCOLON® available from Omeule OY, Finland.
The various materials of the article chassis may be connected by conventional construction elements that withstand the requirement of multiple wash cycles, such as—without limitation—stitching or thermo-fusion bonding like heat-pressing or ultrasonic bonding. Also, certain adhesives or glues may be employed, if these satisfy skin compatibility (including softness) as well as temperature and washing conditions resistance.
The absorbent pad comprises an upper core cover sheet 2100, a lower core cover sheet 2920, and an absorbent core 2200 (see
The upper core cover sheet is adapted to be in liquid contact with the chassis at least in the intake zone and optionally also in the transition zone, if present. The upper core cover sheet may be a conventional topsheet material as used for absorbent articles, e.g., 10 g/m2 spunbonded PP NW, 1.5 to 2.0 dTex. In order to promote the transfer liquid from the fluid handling aid (intermediate storage layer) to the core it has been found to be favorable to use fabrics made of cellulosic fibers e.g., a hydro-entangled cotton web of 35 g/m2, available from Winner Medical, China, under the trade designation PCO-35-N.
The absorbent core of the absorbent pad may comprise a pad acquisition/distribution layer (ADL) 2250, instead of or additionally to a chassis fluid handling aid material 1250, if present. Such an acquisition material is well known to a person skilled in the art, but should be adapted to the particular intended use.
The absorbent core further comprises absorbent material, preferably including superabsorbent polymer (SAP) material, as may be combined with fibrous material, e.g., cellulosic pulp.
The absorbent core may be formed in-situ by combining SAP powder with fibrous material, such as pulp or synthetic webs, preferably stabilized by adhesives, or thermofusion, such as ultrasonic bonding, as well known in the art.
In particular when intended and adapted to female users, it may be preferred that the absorbent core allows to maintain a natural pH in the vaginal region of around 5.5, by exhibiting a pH value of less than 6 or less than 5 or even less than 4 after loading the absorbent core with six fold of its dry weight with 0.9% NaCl solution and measuring the pH by pressing a pH indicator paper (MERCK 1.09527.0001) against the surface of the wetted absorbent core at the point where the NaCl solution has been applied to, e.g. by comprising particular pulp such as “Bliss™ pulp” of International Paper Co. USA. Maintaining a pH below 6 in the absorbent core is beneficial to mask odor based on ammonia or TMA (Tri-Methyl-Amin) typical for menstrual fluid and urine. Furthermore, the low pH inhibits the growth of bacteria similar to the protective acid mantle of the human skin. This allows to relinquish the use of biocides as commonly used in washable menstrual pants.
The absorbent core may be pre-formed such as available under the trade designation eCore from Glatfelter Falkenhagen GmbH, Germany, or MM150.SMT.CSN00.V03.F from Glatfelter Falkenhagen GmbH, Germany, or Gelok 15040-71 S/S of Gelok Int. Corp., Dunbridge, USA, or C1250956 NovaZorb® from Engineered Absorbent Materials (EAM), USA, or SuperCore SCP-200-TCF from McAirlaid's Vliesstoffe GmbH, Germany.
Alternatively, the absorbent core can be made in-line of fluff fibers or a blend for SAP (Super Absorbent Polymer) and fluff-pulp fibers formed in-line using hammer mills and drum formers on a converting line, or by combining SAP particles with synthetic fibers.
The absorbent core is preferably thin, preferably exhibiting a dry thickness of less than about 5 mm, or less than about 3 mm, or less than about 2 mm, but typically more than about 0.1 mm.
The absorbent core may exhibit an overall liquid retention capacity which does not need to be maximized, as the absorbent pad can be easily replaced without changing the chassis.
Thus, the overall liquid retention capacity should be more than about 10 ml, or more than about 20 ml, or more than about 50 ml, or more than about 100 ml, but typically less than about 500 ml, or less than about 300 ml, according to “Centrifuge Capacity” (modified MWSP 241.0) determination, as described below.
In addition, a high local basis capacity, expressed as absorbent capacity per unit area, should not be excessive as otherwise it may result in an undesired bulky wearing impression.
This may be achieved, if the absorbent core exhibits a basis capacity of more than about 2000 ml/m2, or more than about 4000 ml/m2, or more than about 7000 ml/m2. but less than about 16000 ml/m2, or less than about 13000 ml/m2, or less than about 10000 ml/m2, calculated from the above reference centrifuge capacity according to modified EDANA NWSP 241.0.
Optionally, the absorbent core may comprise odor masking or reducing agents, as may be perfumes, odor adsorbents, or bacterial growth inhibitors, such as—without limitation—based on zinc ricinoleate, e.g., Zinc ricinoleate Methylglycinediacetic acid, N,N-BIS(carboxylatomethyl)alanine trisodium salt (MGDA) as commercially available under the designation FRANCHEM® Sorb 30 B from Surfachem Deutschland GmbH;
Optionally, an employed superabsorbent polymer may be modified for an enhanced odor control function, e.g., by comprising urease blocking functionality, such as provided by SAP type OC-301 supplied by LG-Chem, South Korea.
Optionally, a particularly modified cellulose fluff pulp may be utilized, such as exhibiting a pH of less than 6 or less than 5 or even less than 4, e.g., the above referenced “Bliss™ pulp of International Paper Co. USA or Supersoft® Odor Control Fluff Pulp from International Paper, USA.
The application of the absorbent pad varies from daily use, menstruation, light incontinence and heavy incontinence. Therefore, different test methods have to be applied for the determination of the acquisition and rewet depending on the target application, in particular relating to urine or menses.
Preferably, the absorbent core comprises absorbent material, optionally superabsorbent material such that it exhibits an absorbent capacity, as determined according to the centrifuge capacity test as described herein below, of more than 10 ml, preferably 50 ml or even 100 ml depending on the application (menstrual pant or incontinence pant). Preferably, the absorbent pad exhibits a rewet value of at less than 10 g, or less than 5 g, or less than about 1 g when submitted to the urine related acquisition and rewet test for an absorbent pad, as described herein below.
Preferably, the absorbent pad exhibits an acquisition value of at least less than 300 sec, when submitted to the urine related acquisition and rewet test for an absorbent pad, as described herein below.
In particular when intended to be used in the context of menstrual products, the absorbent core may exhibit an acquisition value of at least less than 20 sec, when submitted to the menses related acquisition and rewet test for an absorbent pad, as described herein below, or rewet value of less than about 5 g, when submitted to the menses related acquisition and rewet test for an absorbent pad.
The absorbent pad may further comprise an outer barrier 2900 preventing liquid penetration to the outside, e.g., the garments. Such a barrier is well known in the art, and may be a conventional lower core cover sheet 2920 for hygiene materials, such as film material, e.g., PE or PP films of typically less than about 25 g/m2 or less than about 20 g/m2, optionally in combination with a fibrous layer (also referred to as “textile backsheet” material), hydrophobic NW material, e.g., PP-SMS @18 g/m2 or SSMMSS and the like. Alternatively, the outer layer 2900 may also be liquid permeable, as will be further described herein for designs with a chassis fluid handling aid material positioned on the outer portion of a pocket.
The upper core cover sheet and the lower core cover sheet of the absorbent pad envelope the absorbent core, which can be achieved by conventional designs. In a first execution, see
In a further execution, see
The absorbent pad may be constructed by applying conventional technologies, such as gluing, and/or thermo-bonded, optionally ultrasonic bonding.
Preferably, the absorbent pad exhibits a balanced stiffness or bending resistance, as may ease the handling, in particular when inserting the absorbent pad into the pocket. In particular, for applications where the absorbent pad is to be positioned in the crotch region of a wearer, the absorbent pad should be perceived as soft, or supple, conforming readily to width-wise compression by the legs.
To this end, it may be preferred that the bending stiffness according to “Stiffness of Nonwoven Fabrics Using the Cantilever Test (INDA) NWSP 090.1.R0 (15) is
This may be achieved by applying particular glue or embossing lines to the absorbent pad or its core, which may generally extend longitudinally but with a curved shape.
Optionally, the absorbent pad may comprise handling aids, such as a pouch 3400 on its outer surface, adapted and sized such that one or more fingers can be inserted for pushing the pad into its proper position.
Another optional handling aid for application of the absorbent pad may be a separate application aid exhibiting the required stiffness as described for the absorbent pad, but which is removed after the application and may be re-used for further applications in analogy to a shoehorn.
Optionally, for executions where absorbent pad comprises attachment elements on its surface that may have the tendency to adhere to surfaces prior to be positioned properly, such as adhesive stripes or mechanical fastener hooks, the upper core cover sheet surface of the absorbent pad may comprise a release paper, optionally comprising a removal strip allowing to pull the release paper away, once the pad is put in place.
Optionally the absorbent pad may comprise removal aids as a handling aid. In a first execution, when the upper core cover sheet and the lower core cover sheet are connected in a “butt” mode, whereby the general inner surfaces of the webs are in a touching arrangement, in the outer periphery of the pad, the removal aid may be an enlarged tab like portion of the periphery.
Alternatively, a tab may be connected to the pad, optionally as a loop or arched handle, adapted to finger pouch 3400 for easing application.
It is further a particular aspect of the present invention that the chassis and the absorbent pad as described in the above can be combined to a fully functional absorbent hygiene article system, whereby each of the two may be replaced independently from the other, whereby the absorbent pad is positioned such that the fluid receiving surface is oriented to and in good liquid contact with the intake zone of the chassis. “Good liquid contact” refers to an arrangement, wherein fluid may transfer from the intake zone of the chassis without significant reduction of the fluid transfer properties, when compared to an arrangement of connecting the two elements to each other under laboratory testing conditions combining the two layers by application of gentle pressure.
The user may don the well-fitting chassis, either with an absorbent pad already inserted or without that. Sometimes, applying the absorbent pad after donning of the chassis may be easier and the pad may be properly positioned upon application.
A further particular execution of a hygiene article system 100 is described by referring to
In a second execution, see
Thus, the system according to the present invention provides particular fluid handling properties, in that it allows a fluid handling aid, as may be positioned in the liquid intake region of the article chassis to receive the liquid rapidly and store it by capillary force, but also release the liquid to an absorbent pad, even if this exhibits a smaller size than the chassis fluid handling aid material.
This can be demonstrated by determining the amount of liquid as being released from a material for a fluid handling aid into a smaller sized absorbent pad, according to the test for “Liquid release of fluid handling aid material to ultimate liquid storage material” as described herein below.
A suitable exemplary material for a fluid handling aid material is commercially available under the trade designation ATB Multifunctional Blue A49B60 from Texsus spa, Italy, at 60 g/m2 basis weight. When combined with a 180 g/m2 basis weight airlaid absorbent pad material from Glatfelter GmbH, Germany, code MM180.SMT.CSNOO.V03.F.PEFC.S.046w, the fluid handling aid material released 85.1% of the total fluid pick-up. Similarly, when combined with a 270 g/m2 eCore absorbent pad material from Glatfelter Falkenhagen GmbH, Germany, code MM270.PTB.CSTOO.VOO.R.FSCM.2x0046w.1050d, the fluid handling aid material released 92.0% of the total fluid pick up.
This demonstrates that when removing the absorbent pad from the hygiene article chassis, e.g., for replacing it by a fresh absorbent pad, the chassis fluid handling aid material is dried out to a significant degree and ready to receive further fluid load for release to the fresh absorbent pad.
All percentages are on a weight basis, unless expressly referred to otherwise.
All testing should be performed in a conditioned room maintained at about 23+/−2° C. and about 50+/−2% relative humidity.
All equipment should exhibit an accuracy of at least one more digit than the reporting of the resulting measurements.
If a material exhibits a sidedness and the test results are susceptible to this, the test should be executed according to the intended “in-use” orientation. “NWSP” refers to the “Nonwovens Standard Procedures”, Edition 2015 (suffix R0.15), issued by EDANA, Belgium.
The airlaid material is cut to a width of 46 mm and further enveloped by a hydro-entangled cotton web of 35 g/m2, available from Winner Medical, China, under the trade designation PCO-35-N, thus forming the standard absorbent material at a width of 50 mm.
A further plastic plate of 22 cm by 7 cm and a weight of 140 g is placed over the stripe and the standard absorbent material, and a further weight of 400 g is placed there on, such as to create a pressure of 344 N/m2. The Liquid Uptake on the balance is monitored over the time, and reported as grams liquid at 5, 10, and 30 minutes.
The liquid transfer over the time is monitored on the balance, and reported as grams liquid at 1, 3, and 15 minutes.
For materials as being incorporated into products or articles, these are removed, such as by cutting, from the product or article.
The Acquisition/Rewet measurement of products designed for use in Adult Incontinence Test Method PA07/03 of Hygiene-Technologie GmbH (Hy-Tec), Haan, Germany.
The test employs an apertured Perspex plate of 70 mm by 220 mm with a central cylinder of an inner diameter of 20 mm and a height of 130 mm at a weight of 255 g, adapted such that weights of 2 kg each can be placed on onto the plate on either side of the cylinder. Upon placing the cylinder and the plate with weights centered on the plate, 50 ml of 0.9 w-% saline as synthetic urine are applied to the cylinder, and the acquisition time until complete disappearance of the liquid is recorded as 1st gush acquisition time. 20 mins after that point in time, the second 50 ml are applied, and the 2nd gush acquisition time until disappearance is recorded. After another 20 mins, the 3rd 50 ml are applied and the 3rd acquisition time is recorded. After 5 mins, the weights, plate and cylinder are removed and accurately (i.e., +/−0.01 g or better) weighed 50 g of filter paper of 110 mm by 230 mm, are placed on the test specimen, followed directly by applying a plate without cylinder at 145 g and the 2*2 kg weights. After 15 secs, the weights and plate are removed and the rewetted filter paper is accurately weighed. The three acquisition times are added to the cumulative acquisition time in seconds, and the rewet value is recorded in grams.
The Acquisition/Rewet measurement for the absorbent pads, which are applied during menstruation is based on the specification of PA 05/02 and PA 05/01 from Hygiene Technologie GmbH (Hy-Tec). The sample is placed horizontal on a plate. A ring out of Teflon (80±1 g, inner diameter 30±0.1 mm, height 21.5 mm) is positioned in the middle of the sample. Afterwards, the test fluid artificial menses (solution of demineralized water with 1.4% Tylose H 20 P2, 0.4% Sodium Hydrogen Carbonate, 0.5% Sodium Chloride, 0.025% Alura Red Dye, 10% glycerin) is applied from 1 cm above the ring into the ring. The time until the fluid is absorbed into the pad is measured (=acquisition). After 10 minutes, filter paper (type 604, approximately 10 sheets, 140×85 mm) is weighed and placed with a weight on top of the wetted sample as described above. After 15 s the weight and the filter paper sheets are removed. The filter paper sheets are weighed again. The increased mass of the filter paper sheets due to fluid uptake is calculated (=rewet).
| Number | Date | Country | Kind |
|---|---|---|---|
| 22164271.3 | Mar 2022 | EP | regional |
| 22192264.4 | Aug 2022 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/057846 | 3/27/2023 | WO |
