Absorbent article including reinforced backsheet

In some examples, an absorbent article includes a backsheet comprising one or more reinforced edges, which helps increase the tensile strength of the absorbent article.

TECHNICAL FIELD

This disclosure relates to an absorbent article.

BACKGROUND

Absorbent articles may be configured to collect and/or absorb body fluid discharge, such as urine, aqueous body fluids, mucus, blood, menses, or cellular debris. Examples of absorbent articles include disposable diapers or diaper inserts, adult incontinent pads or briefs, feminine hygiene products, training pants, and other articles that may be disposed against a body surface, by infants or adults. Another example of an absorbent article is an underpad, which may be suitable for use with patient bedding to help protect a mattress from body fluid discharge. The underpad can be disposable in some instances.

SUMMARY

In one example, an absorbent article comprises a first layer that is fluid permeable; a second layer comprising an absorbent material; a third layer that is fluid impermeable, the second layer being positioned between the first and third layers; and a reinforcement layer configured to structurally reinforce the third layer, wherein the third layer has a greater surface area than the reinforcement layer. The third layer is positioned between the reinforcement layer and the second layer. The reinforcement layer comprises a plurality of portions. The reinforcement layer is configured to reinforce at least one edge of the third layer. In some cases, the reinforcement layer comprises a first portion adjacent to a first edge of the third layer and a second portion adjacent to a second edge of the third layer. The first and second edges are opposite edges of the third layer. The absorbent article can further comprise a third portion positioned between the first and second portions. The third portion is substantially centered between the first and second edges of the third layer. The absorbent article can further comprise a sheet of material, wherein opposite edges of the sheet of material are folded toward each other to define the third layer and the reinforcement layer. The sheet of material has a machine direction and a cross direction, wherein the sheet of material is folded along the machine direction to define the third layer and the reinforcement member. In some cases, the third layer has a machine direction and a cross direction, wherein the reinforcement layer has a longitudinal axis that extends in the machine direction. The reinforcement layer is adhered to the third layer. In some cases, the reinforcement layer is ultrasonically bonded to the third layer. The absorbent article has a greatest thickness in a region including the reinforcement layer. The absorbent article can further comprise a fourth layer that is moisture vapor permeable, the fourth layer being positioned between the second and third layers. In some cases, a first region of the absorbent article including the reinforcement layer has a greater tensile strength than a second region of the absorbent article that does not include the reinforcement layer.

In another example, an absorbent article comprises a top sheet that is fluid permeable; an absorbent core; a backsheet that is liquid impermeable and vapor permeable, the absorbent core being positioned between the top sheet and the backsheet, the backsheet comprising at least one reinforced edge. The absorbent article has a greatest thickness at a region including the at least one reinforced edge of the backsheet. The absorbent article can further comprise a reinforcement layer configured to reinforce the at least one edge of the backsheet. The reinforcement layer comprises a plurality of portions. The at least one reinforced edge of the backsheet comprises a first edge and a second edge, the reinforcement layer comprising a first portion adjacent to the first edge of the backsheet and a second portion adjacent to the second edge of the backsheet. The first and second edges are opposite edges of the backsheet. The reinforcement layer further comprises a third portion positioned between the first and second portions. The backsheet has a greater surface area than the reinforcement layer. The reinforcement layer is adhered to the backsheet. In some cases, the reinforcement layer is ultrasonically bonded to the backsheet. The absorbent article can further comprise a sheet of material, wherein opposite edges of the sheet of material are folded toward each other to define the backsheet comprising the at least one reinforced edge. The sheet of material has a machine direction and a cross direction, and wherein the sheet of material is folded along the machine direction to define the backsheet comprising the at least one reinforced edge. The backsheet has a machine direction and a cross direction, the at least one reinforced edge extending in the machine direction. The absorbent article further comprises a moisture vapor permeable layer positioned between the absorbent core and the backsheet. In some cases, a first region of the absorbent article including the at least one reinforced edge has a greater tensile strength than a second region of the absorbent article that does not include the at least one reinforced edge.

DETAILED DESCRIPTION

An absorbent article described herein includes a plurality of layers. In examples described herein, one of the layers is a backsheet and another of the layers is configured to reinforce the backsheet. The reinforced backsheet may help strengthen the absorbent article, e.g., such that the absorbent article may have a strength (e.g., tensile strength) sufficient to lift a patient when the absorbent article is used to reposition the patient.

The absorbent articles described herein include a substrate upon and within which fluid discharge, e.g., liquid insult, may be applied and absorbed. For illustrative purposes, the absorbent article will be discussed in terms of patient care underpads; however, in other examples, the absorbent articles including a reinforced backsheet may be any absorbent product such as, for example, disposable diapers, training pants, feminine hygiene products (e.g., sanitary napkins, panty-liners, or both), adult incontinence products (e.g., adult briefs, pads, or both), protective underwear, pet training pads, and other products, disposable or otherwise, utilized to absorb fluids. Some absorbent articles including a reinforced backsheet described herein may be configured to be disposed against a body surface, by infants or adults, and may be worn in cooperation with garments or may be a product that can be used on its own.

FIG. 1is a schematic cross-sectional view of an example multi-layer absorbent article10, which includes top sheet12, absorbent layer14, moisture vapor permeable layer16, backsheet18, and reinforcement layer20.FIG. 2is an elevation view of absorbent article10and shows reinforcement layer20and backsheet18. Although not illustrated to scale, absorbent article10may be, for example, a patient care underpad, which may have a sheet-like configuration (e.g., relatively thin compared to the width and length). The thickness is measured in the z-axis direction (orthogonal x-z axes are shown inFIG. 1and orthogonal x-y are shown inFIG. 2for ease of description only). When configured as an underpad, absorbent article10may be suitable for use with patient bedding to help protect a mattress from body fluid discharge, as well as to help improve patient comfort, such as by providing padding, by providing a relatively dry surface for the patient, even when absorbent layer14has absorbed fluids, or combinations thereof. In some examples, absorbent article10is used as a disposable product.

Top sheet12is fluid permeable, and is configured to allow a fluid to penetrate readily through its thickness. Top sheet12can be formed from any suitable material, such as a woven material, a nonwoven material, or a combination thereof. Suitable fibers that may be utilized to construct woven and non-woven materials for top sheet12include, for example, natural fibers, e.g., wood or cotton fibers; synthetic fibers, e.g., polymeric fibers such as polyester, polypropylene, or polyethylene fibers; and combinations of natural and synthetic fibers. The fibers may be fixedly secured to each other by adhesives, such as hot melt, or by other techniques, including, for example and without limitation, ultrasonic bonding, heat pressure sealing, and hot air knife bonding.

Example nonwoven materials include, but are not limited to, a non-woven web of fibers; polymeric materials such as thermoplastic films having apertures, plastic films having apertures, and hydro-formed thermoplastic films; porous foams; reticulated foams; reticulated thermoplastic films; and thermoplastic scrims. In examples in which top sheet12is a non-woven web, the web may be spun-bonded, carded, wet-laid, melt-blown, hydro-entangled, or formed using any method suitable for forming a non-woven web. In some examples, at least a portion of top sheet12can be formed of a nonwoven fibrous layer of polyolefinic fibers, which can be multicomponent fibers in some examples.

In some examples, top sheet12can include (e.g., be formed from or at least partially from) one or more bicomponent polymeric fibers. For example, top sheet12can be a fabric with first bicomponent fibers woven with second bicomponent fibers.

Top sheet12, as well as article10, may be compliant, such that it can relatively easily conform to a body of a patient when the patient is positioned on article10. In the example shown inFIGS. 1 and 2, top sheet12defines a patient-interfacing surface of article10. Thus, in some examples, top sheet12may be relatively soft in order to provide the patient or other user of article10with a comfortable interface and to minimize irritation to skin of the patient contacting top sheet12. Although top sheet12is shown as the topmost surface of absorbent article10inFIG. 1, in other examples, absorbent article10can include one or more layers on top of the top sheet12(on the other side of the absorbent layer14), or top sheet12can include more than one layer. For example, absorbent article10can include one or more additional fluid permeable and vapor permeable, or both fluid and vapor permeable layers on top of top sheet12.

Absorbent layer14is positioned between top sheet12and backsheet18, and is configured to absorb fluid that passes through top sheet12. Absorbent article10can be placed against a patient (or other user) or against a patient's or user's clothing such that it is positioned to receive fluid discharge from the patient. When absorbent article10receives fluid discharge, such as an insult of fluid from the patient, a majority, or all, of the fluid may pass through top sheet12and be absorbed by absorbent layer14. Absorbent article10can, but need not be, discarded after one insult of fluid.

Absorbent layer14, which may also be referred to as an absorbent core in some examples, may comprise any one or more absorbent materials, such as, but not limited to, a foam, a nonwoven composite fabric, a hydrogel, a cellulosic fabric, a super absorbent polymer or other superabsorbent material, a woven fabric, paper, wood pulp, cotton linter and cotton wool of any suitable grade, rayon fibers, cotton staple, bleached or unbleached-creped tissue, and composites or other combinations thereof. Example foams include, but are not limited to, inherently hydrophilic foams, e.g., viscose rayon foam; natural or synthetic foamed polymeric materials, e.g., polyurethane, polyether, or styrene/butadiene rubber foams which have been rendered hydrophilic or readily wettable; or the like.

The super absorbent material can, for example, include super absorbent polymer particles. The particle diameter of super absorbent polymer particles can be from about 20 micrometers (μm) to about 850 μm, in some examples from about 110 μm to about 500 μm, in some examples from about 140 μm to about 350 μm. In some examples, the super absorbent polymer particles have an absorption speed of 45 seconds or less. When the absorption speed exceeds 45 seconds, so-called flow back may occur, where body fluids supplied to an absorber flow back outside the absorber.

In some examples, absorbent layer14is an embossed material that defines pockets (e.g., diamond-shaped or pockets of another shape) including an absorbent material, such as a mixture of fluff pulp material and superabsorbent polymer particles.

The material of absorbent layer14may be configured to define any suitable fluid distribution gradient in the z-axis direction, or the x- and y-axis directions, where the distribution gradient may affect how fluid flows through absorbent layer14(e.g., the speed of fluid flow, the direction of fluid flow, or both). For example, an absorbent or superabsorbent material having a faster absorption speed may be used in a central region of absorbent article10(e.g., central relative to the x- and y-axes), while an absorbent or superabsorbent material having a slower absorption speed may be used at the periphery. In other examples, absorbent layer14may be substantially uniform, such that the fluid distribution gradient is substantially the same throughout layer14.

Moisture vapor permeable layer16is configured to allow at least some moisture vapor to escape or pass from absorbent layer14through moisture vapor permeable layer16. The vapor permeability may help provide air circulation through absorbent article10, which may minimize or even prevent vapor build-up. Moisture vapor permeable layer16may be formed from any suitable material, such as, but not limited to, a woven or nonwoven moisture vapor permeable material. In some examples, moisture vapor permeable layer16is also fluid impermeable, while in other examples, moisture vapor permeable layer16is at least partially fluid impermeable.

Backsheet18is substantially fluid impermeable (e.g., fluid impermeable or nearly fluid impermeable) and may help to prevent fluid leakages from absorbent article10. Thus, backsheet18may help prevent liquid absorbed and contained in absorbent layer14from wetting an article that contacts backsheet18of absorbent article10, such as, but not limited to, undergarments, pants, pajamas, or bed sheets. In addition, in some examples, backsheet18is air permeable (e.g., breathable) in order to allow at least some air to pass from absorbent layer14, while substantially preventing fluid from passing through backsheet18. The air permeability may help provide air circulation through absorbent article10, which may minimize or even prevent vapor build-up. The air permeability may improve user comfort.

Backsheet18may be formed from any suitable material or combination of materials that alone or in combination provide a substantially liquid impermeable barrier for article10. For example, backsheet18may include any one or more of: a woven material; a non-woven material; a liquid-impervious fabric; a cellulosic film; a polymeric film such as a thermoplastic film of polyethylene or polypropylene; an impregnated fluid repellent paper; a composite material, e.g., a polylaminate, such as a film-coated non-woven material; or combinations thereof. Although backsheet18is shown as one layer inFIG. 1, in other examples, backsheet18can include multiple layers. In some cases, backsheet18is comprised or consists of a polymeric film of, for example, polyethylene, and a nonwoven fabric of, for example, polypropylene. Further configurations involve backsheet18that is vapor permeable while being liquid impermeable. The basis weight of the backsheet18can be in a range of from about 10 grams per square meter (gsm) to about 40 gsm. In some examples, backsheet18, or at least portions thereof, may be embossed or may be matte-finished to provide a cloth-like appearance, may be colored for ready identification, or both.

Absorbent article10includes reinforcement layer20, which is configured to structurally reinforce backsheet18and increase the tensile strength of backsheet18, as well as the tensile strength of absorbent article10. For example, reinforcement layer20may help increase the amount of weight absorbent article10can support before tearing, rupturing, or otherwise failing, compared to examples in which an absorbent article only includes layers12,14,16, and18. Thus, when absorbent article10is used to lift a patient, e.g., to reposition a patient in bed or to move a patient from one bed to another, reinforcement layer20may help improve the performance of absorbent article10, configure absorbent article10to be used to lift heavier patients compared to absorbent articles that do not include reinforcement layer20, or improve the performance and configure absorbent article10to be used with heavier patients.

In some examples, the regions of absorbent layer including reinforcement layer20have a greater tensile strength than the regions of absorbent article10that do not include reinforcement layer20. In some examples, reinforcement layer20has a greater tensile strength in at least one of the machine direction or the cross direction than one or more of top sheet12, absorbent layer14, moisture vapor permeable layer16, and backsheet18. In some cases, the reinforced portion or region of the absorbent layer has a tensile strength that is at least twice the tensile strength of the other, non-reinforced regions of the absorbent layer.

Reinforcement layer20is connected to backsheet18using any suitable technique. For example, reinforcement layer20may be adhered to backsheet18with an adhesive, reinforcement layer20and backsheet18may be ultrasonically welded together or melted together, or backsheet18and reinforcement layer20may be formed from a common sheet of material, as described with respect toFIG. 3.

As shown inFIG. 1, reinforcement layer20can be directly adjacent to backsheet18and may contact backsheet18. In other examples, one or more additional layers may be positioned between backsheet18and reinforcement layer20. In addition, as also shown inFIG. 1, backsheet18can be positioned between absorbent layer14and reinforcement layer20. In other examples, however, reinforcement layer20can be positioned between absorbent layer14and backsheet18, or absorbent article10can include another reinforcement layer between absorbent layer14and backsheet18.

As shown inFIG. 1, absorbent article10has a greater thickness (as measured in the z-axis direction) at the regions including reinforcement layer20compared to regions that do not include reinforcement layer20.

In the example shown inFIGS. 1 and 2, reinforcement layer20includes a plurality of portions20A-20C. Portions20A-20C can be, but need not be, substantially equal (e.g., equal or nearly equal) in size, as defined by the respective x-axis, y-axis, and/or z-axis dimensions. InFIGS. 1 and 2, portions20A-20C are substantially equal in size and are substantially equally spaced (e.g., equally spaced or nearly equally spaced) from each other. For example, central portion20C can be substantially centered (e.g., centered or nearly centered) between portions20A,20C. In other examples, portions20A-20C may be unevenly distributed relative to backsheet18, while still increasing the tensile strength of absorbent article10.

Reinforcement layer20can, but need not, extend across either the entire span of backsheet18in at least one of the x-axis or y-axis directions in order to provide sufficient structural reinforcement to backsheet18to increase the tensile strength of backsheet18, absorbent article10, or both. Thus, in some examples, such as the example shown inFIGS. 1 and 2, a surface area of reinforcement layer20, e.g., as provided by the surface area of each of the portions20A-20C, is less than a surface area of backsheet18. The surface area can be the surface area in the x-y plane. Configuring reinforcement layer20to have a smaller surface area than backsheet18may provide backsheet18with sufficient reinforcement, while reducing the weight reinforcement layer20adds to article10, as well as reducing the cost of materials used to form article10compared to a reinforcement layer20that is the same surface area as backsheet18.

In the example shown inFIGS. 1 and 2, portions20A and20B of reinforcement layer20structurally reinforce opposite edges18A and18B of backsheet18, while portion20C structurally reinforces a central portion of backsheet18between edges18A,18B. In addition, in the example shown inFIG. 2, because portions20A-20C may each structurally reinforce opposite edges18C,18D of backsheet18, reinforcement layer20may reinforce backsheet18in at least the y-axis direction, and, in some examples, both the x- and y-axes directions.

In some examples, backsheet18has a machine direction (e.g., the y-axis direction in the example shown inFIG. 2) and a cross direction (e.g., the x-axis direction in the example shown inFIG. 2), and a longitudinal axis of each portion20A-20C may extend in the machine direction. For example, portions20A-20C may each extend from edge18C to edge18D in the machine direction. A reinforcement layer20configured to reinforce backsheet18in the machine direction may help increase the tensile strength of absorbent article10. In other examples, however, reinforcement layer20includes one or more portions that reinforce backsheet18in the cross-direction, or in both the machine- and cross-directions.

Although three portions20A-20C are shown inFIG. 2, in other examples, reinforcement layer20can include any suitable number of portions, such as one, two, three, four or more portions. If reinforcement layer20includes one portion, the one portion can have a surface area less than backsheet18or multiple portions that together have a surface area less or equal to backsheet18, while still providing sufficient structural reinforcement to backsheet18to improve the tensile strength of absorbent article10.

While reinforcement layer20can have a surface area greater than backsheet18in some examples, such that reinforcement layer20extends past edges18A-18D of backsheet, and, in some cases, extends past the edges of article10, a reinforcement layer20having a smaller surface area than backsheet18may help prevent a user from grasping absorbent article10by only reinforcement layer20to lift a patient via article10, and, therefore, may help prevent layer20from tearing, rupturing, or otherwise failing before the portion of article10including both backsheet18and reinforcement layer20.

In some examples, portions20A and20B of reinforcement layer20extend to respective edges18A,18B of backsheet18, such that reinforcement layer20includes portions aligned with opposite edges18A,18B of backsheet18. In addition, portions20A-20C extend from edge18C to edge18D of backsheet18, such that reinforcement layer20includes portions aligned with the other edges18C,18D of backsheet18. In other examples, however, one or more of portions20A-20C can be inset relative to one or more of edges18A-18D.

FIGS. 4 and 5illustrate an example absorbent article30in which portions20A and20B are inset relative to edges18A,18B.FIGS. 6 and 7illustrate an example absorbent article40in which portions20A and20B are inset relative to all four edges18A-18D, and portion20C is inset relative to edges18C,18D. Of course, in other examples, absorbent articles can include a reinforcement layer20having other configurations, e.g., configurations in which one or more portions20A-20C are inset relative to only one edge18A-18D of backsheet18, or two edges18A-18D, which may or may not be opposite each other, or three edges18A-18D.

The distance “A” by which one or more portions20A,20B are inset relative to an edge18A or18B and the distance “B” by which one or more portions20A-20C are inset relative to an edge18C or18D may vary, but may be selected such that reinforcement layer20increases the tensile strength of the respective absorbent articles and helps prevent backsheet18or absorbent article10from tearing, rupturing, or otherwise failing when a user holds the absorbent article at or near its edges to lift a patient. Thus, distances “A” and “B” may be relatively small compared to the x-axis and y-axis dimensions of backsheet18such that portions20A-20C substantially reinforce backsheet18from edge18A to edge18B and/or from edge18C to edge18D.

Reinforcement layer20may be formed from any suitable material that, when connected to backsheet18, increases the tensile strength of backsheet18. In some examples, reinforcement layer20is formed from the same material as backsheet18. For example, as shown inFIG. 3, at least a portion of reinforcement layer20can be formed by folding first and second edges of a sheet of material22defining backsheet18towards each other to define first and second opposite edges18A,18B of backsheet18and portions20A,20B of reinforcement layer20. Sheet22can be folded in, for example, a machine direction, such that the material defining portions20A,20B of reinforcement layer20extend in a machine direction from one edge18C of backsheet18to an opposite edge18D. Sheet22can include one layer of material or can include multiple layers, which are folded together to define backsheet18and portions20A,20B of reinforcement layer20. Once folded, portions20A,20B can be further connected to backsheet18using any suitable technique, such as by adhering the flaps that define portions20A,20B to backsheet18, by ultrasonically welding the flaps to backsheet18, by melting the flaps to backsheet18, or any combination thereof.

In some examples, such as, but not limited to, examples in which sheet22is folded to define backsheet18and portions20A,20B of reinforcement layer20, portions20A,20B are aligned with edges18A,18B of backsheet18and, in some instances, edges18C,18D. However, as discussed above, in other examples, one or more portions20A-20C need not be aligned with edges18A,18B of backsheet18, as shown inFIGS. 4 and 5or with edges18C,18D of backsheet18, as shown inFIGS. 6 and 7.

In other examples, rather than being formed from a unitary sheet22of material, reinforcement layer20can be formed separately from backsheet18and subsequently attached to backsheet18, e.g. via an adhesive, ultrasonic welding, melting the materials together, or another suitable technique.

The absorbent articles described herein can be assembled using any suitable method. In one example, a method includes attaching absorbent layer14to a top sheet12, and if being used, moisture vapor permeable layer16, and attaching backsheet18to top sheet12and absorbent layer14, and, if being used, moisture vapor permeable layer16. In examples in which backsheet18and reinforcement layer20are formed from a common sheet22of material, backsheet18and reinforcement layer20are at least partially connected before backsheet is assembled to top sheet12and absorbent layer14. In examples in which backsheet18and reinforcement layer20are formed separately and subsequently attached, however, the method can include attaching reinforcement layer20(e.g., the individual portions20A-20C) to backsheet18prior to, after, or while attaching backsheet18to top sheet12and absorbent layer14. The steps of the method described herein can be performed in any suitable order.

A method of using an absorbent article described herein can include, for example, positioning one or more absorbent articles10,30,40such that a patient is lying or otherwise on top of the absorbent article. For example, the absorbent article can be positioned between a patient and the patient's bedding. The method may further includes lifting the patient via the absorbent article by, for example, at least grasping near or at opposite edges of the absorbent article (e.g., edges corresponding to edges18A,18B and/or edges18C,18D of backsheet) and lifting the absorbent article on which the patient is positioned. Lifting the patient via the absorbent article can include, for example, repositioning the patient in a bed or transferring the patient from one bed to another bed.