阅读说明：本技术 吸收层压件、吸收芯和利用该吸收层压件的一次性制品及相关方法 (Absorbent laminates, absorbent cores and disposable articles utilizing the same and related methods ) 是由 保罗·M·达克 H·J·赫梅莱夫斯基 于 2017-12-14 设计创作，主要内容包括：在中间基底的两侧上具有SAP的吸收性多层层压件,该基底包含可润湿纤维素纤维。包括这种吸收层压件的吸收芯。包括这种吸收芯的吸收制品,诸如保护性内衣、成人内裤、婴儿尿布和护理垫,以及包括这种吸收层压件和芯的患者支撑垫,诸如底垫和骶骨垫。(An absorbent multi-layer laminate having SAP on both sides of an intermediate substrate comprising wettable cellulosic fibers. An absorbent core comprising such an absorbent laminate. Absorbent articles such as protective undergarments, adult underpants, baby diapers and nursing pads comprising such absorbent cores, and patient support pads such as underpads and sacral pads comprising such absorbent laminates and cores.)

1. An absorbent laminate comprising:

A first sublayer comprising superabsorbent polymer (SAP) particles and an adhesive supporting the SAP particles in a porous matrix, the SAP particles in the first sublayer having a basis weight of 20 grams per square meter (gsm) to 130 gsm;

A second sub-layer comprising SAP particles and an adhesive supporting the SAP particles in a porous matrix, the SAP particles in the second sub-layer having a basis weight of from 20gsm to 130 gsm; and

A third sub-layer disposed between and bonded to the first and second sub-layers, the third sub-layer comprising a nonwoven web of wettable cellulosic fibers having a basis weight of from 6gsm to 80 gsm.

2. The absorbent laminate of claim 1, wherein the third sub-layer comprises a hydroentangled nonwoven web having a basis weight from 20gsm to 80 gsm.

3. The absorbent laminate of claim 2, wherein the third sub-layer comprises a tissue having a basis weight of from 15gsm to 35 gsm.

4. The absorbent laminate of claim 1, wherein the third sub-layer comprises regenerated cellulose fibers.

5. the absorbent laminate of claim 1, further comprising:

A fourth sublayer bonded to the first sublayer such that the first sublayer is disposed between the fourth sublayer and the third sublayer, the fourth sublayer comprising tissue; and

A fifth sublayer bonded to the second sublayer such that the second sublayer is disposed between the fifth sublayer and the third sublayer, the fifth sublayer comprising tissue.

6. The absorbent laminate of claim 5, wherein the absorbent laminate has a thickness of less than 1.3 millimeters (mm).

7. The absorbent laminate of claim 6, wherein the absorbent laminate has a tensile strength of at least 40 newtons per 50 millimeters (N/50mm) in at least one direction.

8. The absorbent laminate of claim 5, wherein the tissue of at least one of the fourth and fifth sub-layers is creped and/or through-air dried.

9. The absorbent laminate of claim 5, wherein the thickness of the second sub-layer is equal to the thickness of the first sub-layer.

10. The absorbent laminate of claim 5, wherein the basis weight of the SAP particles in the second sub-layer is equal to the basis weight of the SAP particles in the first sub-layer.

11. the absorbent laminate of claim 10, wherein the basis weight of the adhesive in the first sub-layer is from 0.5gsm to 5gsm and the basis weight of the adhesive in the second sub-layer is from 0.5gsm to 5 gsm.

12. A method of making an absorbent laminate, the method comprising:

Distributing an adhesive and superabsorbent polymer (SAP) particles on a first side of a nonwoven web of wettable cellulosic fibers, the nonwoven web defining a first sub-layer, such that the adhesive supports the SAP particles in a porous matrix to define a second sub-layer, the nonwoven web having a basis weight of from 6 grams per square meter (gsm) to 80gsm, the SAP particles in the second sub-layer having a basis weight of from 20gsm to 80 gsm;

Distributing the adhesive and superabsorbent polymer (SAP) particles on a second side of a nonwoven web of wettable cellulosic fibers such that the adhesive supports the SAP particles in a porous matrix to define a third sub-layer, the SAP particles in the third sub-layer having a basis weight of from 20gsm to 80 gsm.

13. The method of claim 12, further comprising:

Applying a fourth sublayer to the first sublayer such that the fourth sublayer is adhered to the first sublayer with the first sublayer disposed between the fourth sublayer and the third sublayer, the fourth sublayer comprising tissue when the adhesive of the first sublayer is tacky; and

Applying a fifth sublayer to the second sublayer such that the fifth sublayer is adhered to the second sublayer with the second sublayer disposed between the fifth sublayer and the third sublayer, the fifth sublayer comprising tissue when the adhesive of the second sublayer is tacky.

14. An absorbent core for a disposable absorbent article, the absorbent core comprising: one or more sheets of the absorbent laminate of any one of claims 1-11 defining a plurality of layers of the absorbent laminate.

15. The absorbent core of claim 14, wherein a single sheet of absorbent laminate is folded to define multiple layers of the absorbent laminate.

16. the absorbent core of claim 14, wherein a plurality of sheets of absorbent laminate are stacked to define a plurality of layers of the absorbent laminate.

17. the absorbent core of claim 14, further comprising:

An additional sheet of the absorbent laminate of claim 5 bonded to an outermost one of the sub-layers of the absorbent laminate.

18. The absorbent core of claim 17 wherein the multi-layer absorbent laminate has a combined width and a combined length greater than the combined width, the combined length extending from the first end to the second end of the absorbent core, the length of the absorbent laminate of the additional sheet being different than the combined length.

19. The absorbent core of claim 18 wherein the combined length of the multi-layer absorbent laminate is from 50% to 70% of the length of the absorbent laminate of the additional sheet.

20. The absorbent core of claim 19 wherein the multi-layer absorbent laminate is defined by a folded first sheet of absorbent laminate and the additional sheet of absorbent laminate is unfolded.

21. The absorbent core of claim 14, wherein the absorbent core is configured to exhibit greater than 70% elasticity when partially hydrated.

22. The absorbent core of claim 14, wherein the absorbent core is configured to add 145 milliliters (mL) of water at 5 x 10 when added to a 100mm x 100mm portion of the absorbent core³Pa, exhibits less than 150X 10 for the second compression cycle³A strain-based softness of Pa.

23. The absorbent core of claim 14, wherein the absorbent core is configured such that when 100 milliliters (mL) of water is added to a 100mm x 100mm portion of the absorbent core,Exhibits less than 4 x 10 for the first compression cycle at 10% strain³A strain-based softness of Pa.

24. A disposable absorbent article comprising:

A topsheet, which is liquid permeable;

A backsheet, which is liquid impermeable; and

The absorbent core of claim 14 disposed between the topsheet and the backsheet.

25. The absorbent article of claim 24, wherein the absorbent article does not include a discrete acquisition-distribution layer other than the absorbent core.

26. The absorbent article of claim 24, wherein the absorbent article is a mattress and the absorbent core is at least 12 inches wide and at least 18 inches long.

27. A method of making an absorbent core for a disposable absorbent article, the method comprising:

Stacking a plurality of layers of the absorbent laminate of claim 1.

28. The method of claim 27, wherein the multiple layers are stacked by folding a single sheet of absorbent laminate onto itself.

29. A disposable patient support article comprising:

A support core comprising one or more sheets of the absorbent laminate according to any one of claims 1-11, defining a multi-layer absorbent laminate; and a liquid impermeable layer bonded to the support core;

Wherein the support core has a width of at least 8 inches and a length of at least 8 inches.

30. The patient support article of claim 29, further comprising:

An additional sheet of the absorbent laminate of claim 5 bonded to an uppermost one of the sub-layers of the absorbent laminate.

31. The patient support article of claim 29, wherein the support core is a first support core, and further comprising:

A second support core comprising one or more sheets of the absorbent laminate according to any one of claims 1-11, defining a multi-layer absorbent laminate;

Wherein the second support core is bonded to the liquid impermeable layer and is laterally spaced apart from the first support core.

32. The patient support article of claim 29, wherein the liquid impermeable layer is a backsheet, and further comprising:

A topsheet; wherein the support core is disposed between the backsheet and the topsheet such that the backsheet and the topsheet form a shell in which the support core is disposed.

33. The patient support article of claim 32, wherein the topsheet is liquid permeable.

34. The patient support article of claim 32, wherein the topsheet is liquid impermeable.

35. The patient support article of claim 32, wherein the topsheet is water vapor permeable.

36. The patient support article of claim 29, wherein the patient support pad is configured to allow liquid to be delivered to the SAP particles prior to positioning the patient support pad under a patient.

37. The patient support article of claim 36, wherein the liquid impermeable layer defines a shell, the support core is disposed in the shell, and the patient support article further comprises:

A container containing a volume of liquid in an amount sufficient to swell at least a portion of the SAP particles to at least a desired elasticity when absorbed by the SAP particles;

Wherein the container is disposed in the housing and is configured to rupture to release the liquid into the housing.

38. The patient support article of claim 29, wherein the backsheet and the topsheet cooperate to define at least a portion of an adult protective undergarment or pant and the adult protective undergarment or pant is configured such that the support core aligns with at least a portion of one of a wearer's buttocks when worn by a user.

39. The patient support article of claim 29, wherein the backsheet and the topsheet cooperate to define at least a portion of a pad configured to be joined with an absorbent article.

40. The patient support article of claim 29, wherein the backsheet and the topsheet cooperate to define at least a portion of a pad having a skin adhesive configured to adhere the pad directly to the skin of the patient.

41. The patient support article of claim 29, wherein the pad is shaped or contoured to cover a portion of a human body.

42. The patient support article of claim 29, wherein the bottom sheet and the top sheet cooperate to define at least a portion of a base of a mattress or a base pad.

43. The patient support article of claim 29, wherein the backsheet and the topsheet cooperate to define at least a portion of a base of a seat cushion.

44. a method, comprising:

Delivering a liquid to a support core of a disposable patient support article according to claim 29; allowing the support core to absorb a sufficient volume of liquid to increase the resiliency of the support core when compressed; and

After delivering the liquid to the support core, disposing the patient support article between at least a portion of a patient and a surface supporting the at least a portion of the patient.

Technical Field

the present invention relates generally to absorbent laminates for disposable absorbent products, such as mattresses or chassis, adult incontinence briefs, protective pull-up undergarments, and baby diapers; more particularly, but not by way of limitation, to absorbent materials, such as laminates, that are more elastic than at least some prior art absorbent laminates, and methods of making elastic absorbent laminates and disposable articles containing elastic absorbent laminates to absorb exudates from a user and/or support the user.

Background

Examples of disposable absorbent articles that can be worn by a user include infant diapers, training pants and adult incontinence briefs and undergarments, all of which can be made in a disposable form, for example using a nonwoven material. The terms "absorbent article" and "absorbent garment" refer to garments or articles which absorb and contain exudates and, more specifically, refer to garments or articles which are placed against or in proximity to the body of the wearer to absorb and contain the various exudates discharged from the body. Such garments or articles include diapers, training pants, feminine hygiene products, bibs, wound dressings, bed pads, and adult incontinence products. By INDA definition, "nonwoven" fabrics are broadly defined as sheets or webs that are bonded together by mechanically, thermally, or chemically entangling fibers or filaments (and by perforating the film). They are flat, perforated plates made directly from individual fibers or from molten plastic or plastic film. They are not made by weaving or knitting and do not require conversion of the fibers into yarns. The basis weight of nonwoven fabrics is typically expressed as gsm or grams per square meter. In this context, "disposable" refers to articles that are designed to be discarded after limited use rather than being laundered or otherwise restored for reuse. Disposable absorbent products have found wide acceptance in the marketplace for a variety of applications, including infant and adult incontinence care, in view of the manner in which these products can provide effective and convenient liquid absorption and retention while maintaining wearer comfort.

Such disposable absorbent articles typically include a topsheet that is disposed closest to the wearer during use, a liquid impermeable backsheet or outer cover, and an absorbent core between the topsheet and the backsheet. "liquid impermeable," when used to describe a layer or multilayer laminate, means that a liquid, such as urine, will not pass through the layer or laminate under normal conditions of use, in a direction generally perpendicular to the plane of the layer or laminate at the point of liquid contact. In some cases, such disposable absorbent articles further include an acquisition-distribution layer ("ADL") disposed between the topsheet and the absorbent core. "absorbent core" refers to a structure located between the topsheet and the backsheet of an absorbent article for absorbing and containing liquids received by the absorbent article, and may include one or more substrates, absorbent polymer materials, adhesives, or other materials to bond the absorbent material in the core, and, for purposes of this invention, includes the disclosed absorbent laminates.

Examples of disposable absorbent articles that can be worn by a user include infant diapers, training pants, and adult incontinence briefs and undergarments, all of which can be made in a disposable form. "disposable" refers to articles that are designed to be discarded after a limited use rather than being laundered or otherwise restored for reuse. Disposable absorbent products have found wide acceptance in the marketplace for a variety of applications, including infant and adult incontinence care, in view of the manner in which these products can provide effective and convenient liquid absorption and retention while maintaining wearer comfort. Such disposable absorbent articles typically include a topsheet that is configured to be closest to the wearer during use, a liquid impermeable backsheet or outer cover, and an absorbent core between the topsheet and the backsheet. In some cases, such disposable absorbent articles further include an acquisition-distribution layer (ADL) disposed between the topsheet and the absorbent core.

Disposable absorbent articles such as disposable diapers, training pants, adult incontinence articles, and feminine hygiene articles are well known in the art. These articles are designed to receive and retain bodily exudates, such as urine or feces, that are discharged from the body of the wearer.

Generally, disposable absorbent articles include a liquid permeable topsheet facing the body of the wearer, a liquid impermeable backsheet facing the garment of the wearer, an acquisition distribution layer underlying the liquid permeable topsheet, and an absorbent core interposed between the acquisition distribution layer and the backsheet. In operation, fluid leaving the body of the wearer enters the disposable absorbent article through the topsheet and is distributed through the acquisition distribution layer for storage in the absorbent core. The backsheet prevents any excess fluid that is not absorbed from exiting the disposable absorbent article. For disposable absorbent articles such as sanitary napkins intended to be worn with other garments, the backsheet may be the garment-facing layer and generally helps prevent soiling of the garment. Since their introduction into the market, disposable diapers have been improving in terms of comfort, fit, and functionality.

U.S. patent No.9,398,986 discloses certain prior art examples of training pants, and U.S. patent nos. 6,976,978 and 4,940,464 disclose certain prior art examples of disposable incontinence garments or training pants.

One example of such a disposable absorbent article is shown in fig. 1A-1B, which depict a lower plan view and a perspective view, respectively, of an adult protective undergarment 10. The undergarment 10 includes a chassis 14 having a front waist portion 18, an opposing back waist portion 22, and a crotch portion 26 extending between the front and back waist portions 18, 22. The chassis 14 also includes an outer surface 30 that is configured to face away from the wearer during use of the diaper, and an opposing body-facing surface 34 that is configured to face toward the wearer during use of the diaper.

As shown in fig. 1A and 1B, the undergarment 10 further includes a pair of front elastic side panels 38 and a pair of back elastic side panels 42 configured to connect the back waist region 22 to the front waist region 18 in a well-known configuration, wherein the bottom of the left side 46 of the chassis defines a first leg opening 50 for the left leg of the wearer, and wherein the right side 54 of the chassis defines a second leg opening 58 for the right leg of the wearer. In the illustrated construction, each side panel 38,42 includes a connecting portion 62, the connecting portion 62 being configured to be joined to the connecting portion 62 of the other side panel 38, 42. Specifically, the connecting portion 62 of the left front side panel 38 is configured to be joined to the connecting portion 62 in the left back side panel 42, and the connecting portion 62 of the right front side panel 38 is configured to be joined to the connecting portion 62 of the right back side panel 42, such that the waist regions 18,22 and the side panels 38,42 cooperate to define a waist opening 66, as shown in fig. 1B. The attachment portions 62 of the respective side panels may be permanently joined together to define a tearable side seam 70, such as by adhesive, ultrasonic, or thermal bonding. "bonded" refers to the joining, adhering, connecting, attaching, etc., of two elements. Two elements will be considered to be bonded together when they are bonded directly to one another or to one another, such as when each element is bonded directly to intermediate elements. Such tearable side seams are generally not refastenable, thereby rendering the article unusable once opened. Alternatively, the attachment portions 62 of the respective side panels may be removably joined to define refastenable or adjustable side seams, such as by hook and loop fasteners. Hook and loop fasteners are mechanical fasteners comprising hooks, such as a hook fastener portion, configured to engage loops in the loop fastener portion or fibers of a piece of fabric; for example, a nonwoven or woven fabric having fibers defining open or loop areas with hooks that can extend and engage. An example of such a hook and loop fastener may be referred to as VELCRO.

A disposable article of this type is shown in fig. 1A and 1B, with the outer surface 30 generally defined by a water-impermeable backsheet, and the body-facing surface 34 generally defined by a water-permeable topsheet. As shown in fig. 1A, the undergarment 10 also includes an absorbent core 74 and an acquisition-distribution layer or "ADL" 78 disposed between the absorbent core 74 and the topsheet. When used in the singular, "a layer" can be a single element or a plurality of elements. For example, multiple sheets may together define a single layer, e.g., a layer that the sheet of that layer having a particular function contributes to.

1. Absorbent core and acquisition-distribution layer

An important component of disposable absorbent articles is the absorbent core. Conventional absorbent cores typically comprise cellulosic fluff pulp and superabsorbent polymers, or "SAPs", such as hydrogel-forming polymeric materials. "superabsorbent" or "superabsorbent material" or "SAP" refers to a water-swellable, water-insoluble organic or inorganic material that, under the most favorable conditions, is capable of absorbing at least about 15 times its weight in an aqueous solution containing 0.9 weight percent sodium chloride, and more desirably at least about 30 times its weight in an aqueous solution containing 0.9 weight percent sodium chloride, and even more desirably at least about 50 times its weight in an aqueous solution containing 0.9 weight percent sodium chloride. The SAP material may be natural, synthetic, and modified natural polymers and materials. In addition, the SAP material may be an inorganic material, such as silica gel, or an organic compound, such as a cross-linked polymer. The inclusion of SAP in an absorbent core generally increases the volume of fluid (e.g., urine) that can be absorbed by a given volume of absorbent core relative to a similarly sized core having only fluff pulp. The inclusion of SAP in the absorbent core also generally increases the ability of the absorbent core to retain absorbed liquid against pressure relative to a similarly sized absorbent core of fluff pulp alone, thereby providing lower rewet and better skin dryness.

Over time, absorbent cores for such articles have become thinner and thinner, with SAP being included in increasing amounts to replace traditional cellulose pulp and other fillers and absorbents. The benefit of increasing the amount of SAP and decreasing the amount of fluff pulp is that the core can be made thinner while still being able to acquire and store large amounts of discharged body fluid. Such thinner core materials may be manufactured off-line and may be introduced as a continuous web in a conventional manufacturing process. However, such thinner core designs may also have certain technical challenges or problems that must also be addressed in general. One such problem is that they typically lack sufficient thickness to provide the required void volume to capture and control the surge of liquid, and therefore typically require an additional acquisition-distribution layer or "ADL" to handle the fluid during insult. Another such problem is that thinner absorbent cores with a predominant SAP may have relatively low structural integrity after absorbing liquid. In some cases, a relatively small amount of thermoplastic adhesive material, such as a fibrous thermoplastic adhesive material, may be included to physically stabilize the SAP. However, when the basis weight of such absorbent cores is sufficient to provide the desired absorbent energy, the relative stiffness of the absorbent core may be higher and less garment-like, particularly when adhesives or other means are included to physically stabilize the SAP. Relatively thin, there is an inherent conflict between sufficient absorption and wet integrity. For example, a flicking adult incontinence product may require a 25mm wide core to fit comfortably, but requires about 400gsm of SAP due to the relatively small size to provide the required absorbent capacity; however, such narrow cores with such high basis weights may be difficult to provide in a stable long-running package suitable for use in commercial production lines.

While these thinner, predominantly SAP-containing cores provide advantages such as generally providing better fit for the wearer, they also present various challenges. One such challenge relates to the collection and distribution of liquid contaminants. In conventional core designs, liquid diffuses radially from the point where it strikes or contaminates the core. Thus, it is not usually dispersed over the core surface, but rather its transport can be localized. This challenge is exacerbated by "gel blocking," which refers to the prevention of liquid transport through the core by swelling and gelling of the superabsorbent material as it absorbs and retains liquid. Gel blocking can lead to leakage of the article when the core is unable to absorb and retain liquid at a rate that meets or exceeds the rate at which the liquid reaches the core. To address this challenge, the properties of permeability, particularly the capillary action and under the wearer's applied pressure, are often divided between two separate structures. Generally, ADLs provide permeability to rapidly acquire liquid as it is added to the product (to prevent uncontrolled surface run-off), and then the acquired liquid spreads or distributes over a larger surface area of the absorbent core at a rate at which the core is able to absorb the liquid, without undesirable internal run-off and leakage. The absorbent core, in turn, draws liquid into the core and provides capillary suction to reduce wetness in the ADL, thereby presenting the wearer with a relatively dry ADL surface and returning the ADL portion to its original state for collection of subsequent liquid insults.

Examples of certain absorbent cores and articles that address some or all of the foregoing problems are disclosed in U.S. patent application publication No. US2015/0245958a1, which is incorporated by reference herein in its entirety. This application discloses examples of absorbent laminates and folded multi-layer absorbent cores comprising superabsorbent polymer particles ("SAP") and one or more layers of material, such as cotton.

2. Patient support article

Non-ambulatory persons, such as those confined to beds, wheelchairs, operating tables, and/or surgical subframes, often develop decubitus ulcers, commonly referred to as pressure sores or decubitus ulcers. Pressure ulcers may form on parts of the body where blood circulation is restricted due to high pressure, for example, at the interface of a person's skin and a support surface. The pressure at this interface may be referred to in the art as "skin interface pressure" or "TIP". Pressure ulcers generally develop when the TIP at a given location increases to a level sufficient to restrict blood flow to soft tissue, and may most often occur in soft tissue areas, such as skin covering a larger skeleton relatively closer to the skin, e.g., the sacrum, coccyx, heel, and hip. Such an increase in TIP typically occurs in soft tissue over these bones because the bones and overlying soft tissue typically protrude beyond the surrounding area of the soft tissue and thus support a relatively large portion of the person's weight rather than the area immediately surrounding the soft tissue, and/or because relatively thin soft tissue between the bones and skin is less effective than the surrounding area in distributing the pressure created by the patient's weight. One or both of these factors may help to cause increased TIP and reduced blood flow to these localized areas. For example, when a person lies on his or her back, a relatively small soft tissue area overlying the heel of the person protrudes more than the surrounding tissue areas (e.g., the person's ankle) and is covered by a layer of soft tissue that is thinner than the rest of the person's leg (e.g., the lower leg). As a result, the human heel carries more weight of the patient's leg over a smaller area than the surrounding tissue area, resulting in a TIP at the human heel that is higher than the surrounding soft tissue area and potentially inhibiting blood flow to the soft tissue of the human heel.

many attempts have been made in the prior art to reduce the occurrence of pressure sores. In general, patient support structures used to alleviate pressure ulcers can be generally considered dynamic or static. A dynamic support structure, such as a dynamically controllable pad or cushion, is a dynamic support structure whose characteristics dynamically change, usually actively at different locations, to reduce the likelihood that TIP restricts blood flow at any one point for a sufficient time to cause a pressure ulcer, or a sensor and feedback loop indicative of TIP allows the control system to respond and reduce the local increase in TIP before a pressure ulcer occurs. While such systems may be practical for patients confined to bed, they may be undesirable for patients in wheelchairs due to the difficulty in maneuvering equipment associated with such dynamic support structures. Dynamic support structures, such as cushions, may also be cost prohibitive for some patients due to their relatively high cost.

Static support structures, such as static pads or pads, typically have one of two types: (1) bladder cushion and (2) foam cushion. The bladder liner is typically a flexible wall bag, such as a plastic or polymeric bag, filled with a fluid, such as air or water, or a gel, such as ethylene glycol, polyethylene glycol, silicone, and/or the like. In contrast, foam cushions are typically solid foam blocks or foam laminate structures. Foam cushions are generally the cheaper of the two types of cushions. However, foam pads may be undesirable because they may retain thermal energy and cause an increase in temperature at the skin interface between the patient's skin and the pad, which is believed to be a contributing factor to the development of decubitus ulcers. In contrast, bladder pads tend to be more expensive, but also tend to distribute forces better than foam pads, thereby reducing TIP, which many in the art consider to be the primary cause of pressure ulcers. Some bladder cushions may be as lightweight and/or low density as foam cushions. However, bladder pads (e.g., foam pads) may tend to retain thermal energy and cause a temperature increase at the skin interface between the patient's skin and the pad. Another disadvantage of bladder cushions is that they tend to lift the patient to a greater height than foam cushions.

One example of a prior art attempt to bond a pad into an incontinence article is disclosed in U.S. patent No.4,114,621, which describes an incontinence garment for a bed-bound patient that includes a "slightly stiff pad" overlying the bed, with the buttocks of the patient lying on top distributing force over a larger area of the patient's soft tissue to alleviate pressure ulcers.

Disclosure of Invention

The present disclosure includes embodiments of absorbent materials, such as laminates that are more elastic than at least some prior art absorbent laminates, and methods of making elastic absorbent laminates and disposable articles comprising elastic absorbent laminates for absorbing exudates from a user and/or supporting a user. For example, some embodiments of the absorbent materials of the present invention include a laminate having an intermediate substrate layer of a nonwoven, such as a spunlace, sandwiched between two layers, each layer including an adhesive supporting SAP particles in a porous matrix. As used in this disclosure, a "matrix" is a porous structure through which a fluid may pass, such as an open-cell foam, and may, but need not, have a regular or uniform repeating pattern of substructures, such as a honeycomb structure. When such a matrix is in a relaxed configuration, wherein the matrix is not in a stretched or compressed state, the relative position of the SAP particles is fixed. In some embodiments, the adhesive/SAP layer is bonded to the intermediate substrate layer. Some embodiments include an additional tissue or nonwoven outer layer on the outer side of the respective adhesive/SAP layer opposite the intermediate substrate layer; in such embodiments, the adhesive/SAP layer may be bonded to the outer layer but not to the intermediate substrate layer, but may simply be folded together with the intermediate substrate layer to define their relative positions, for example in a substantially fixed relationship.

Some embodiments of the absorbent material of the present invention provide a level of permeability and capillary action sufficient to form an absorbent core that can function without discrete or conventional ADLs. "capillary action" refers to the tendency of a wick to spread liquid away from the point of entry through the wick (by the attractive interaction of liquid molecules and the attractive relative force of solids) to resist gravity due to surface tension. For example, a relatively high capillary action generally tends to wet a large portion or percentage of the core and resists drainage of liquid from the core under the force of gravity, so that the SAP in the core absorbs liquid more fully, e.g., due to such resistance to drainage resulting in a longer exposure time between the SAP and the liquid. Such an absorbent core can collect and store bodily fluids, such as urine from an adult male or female, without discrete or traditional ADLs, at a rate sufficient to reduce or eliminate internal run-off and leakage of fluid insults at a rate corresponding to the intended use, wherein the article is configured to the size of use. Some such embodiments of the absorbent laminate of the present invention also have a basis weight that is predominantly SAP, but still have relatively high flexibility and physical integrity when wet. In addition, it is physically thin enough for forming an off-line absorbent core, yet thin enough to provide a roll form that can be unrolled at a sufficient rate for the on-line manufacture of absorbent articles. In addition, the flexibility of the core further benefits from the fact that the various layers of the core need not be fixed (and thus can slide relative to each other). Furthermore, because the core of the present invention does not need to be paired with a separate ADL, additional layers of the absorbent laminate may instead be added in the space that the ADL would otherwise occupy, and because the additional layers are themselves absorbable, it imparts greater absorbency to the core in the target or insult area.

Some embodiments of the absorbent materials of the present invention provide a level of physical elasticity, particularly in the thickness of the sheet or web of material, sufficient to form various embodiments of patient support articles, such as mattresses, breast pads, liners, and disposable articles and garments including support pads formed from the absorbent materials of the present invention, which may be similar in some respects to conventional liners. For example, a liquid may be added to one or more layers of the absorbent material of the present invention in the patient support cushion to swell the SAP and become more elastic than in its dry state. Once hydrated, each SAP particle acts like a tiny balloon, largely retaining fluid under pressure, but also elastically deforming and interacting with adjacent SAP particles to distribute forces over a larger area than if the patient were supported by a hard surface, thereby reducing the maximized TIP, which would otherwise be higher. Unlike conventional fluff/SAP pads, the laminate of the present invention is in most cases significantly more elastic in compression, that is, it is capable of elastic recovery from deformation in the z-direction. This can be important because pads comprising the laminate of the present invention typically do not form ridges and bumps when they are partially hydrated. In contrast, the hard protrusions and ridges formed by conventional fluff/SAP pads may be a factor in the development of pressure sores. In some such embodiments of patient support articles, the absorbent material of the present invention can distribute forces more efficiently than conventional foam pads, and in some cases, more efficiently than conventional bladder pads, while also being less expensive than bladder pads.

Some such embodiments of the patient support article of the present invention may exhibit compression resiliency properties resulting in similar elasticity over multiple compression cycles, which may occur, for example, when a patient is repositioned on a surface over time. Alternatively or additionally, some such embodiments of the patient support article of the present invention may also be configured to absorb body fluids of a patient, e.g., with an additional absorbent core, which may also be formed from one embodiment of the absorbent material of the present invention. Alternatively or additionally, some such embodiments of the patient support article of the present invention may provide improved breathability at the skin interface to reduce moisture on the patient's skin. Alternatively or additionally, some such embodiments of the patient support article of the present invention are configured to exhibit improved thermal properties relative to conventional cushions to reduce the temperature at the skin interface at the skin of the supported patient. Furthermore, because the absorbent material of the present invention can be configured to absorb liquid very quickly, some embodiments of the patient support article of the present invention can be shipped with the absorbent material in a dry state to reduce shipping costs, and a liquid, such as water, can be added to increase the elasticity of the SAP when in use.

In some cases, maximum softness and elasticity of the materials and laminates of the present invention can be achieved, for example, by pre-hydrating the material or laminate or product (e.g., a pad comprising the material or laminate) with an amount of liquid, such as tap or distilled or physiological saline. For example, products used in operating rooms may be filled with sterile water or physiological saline. In other cases, a product comprising one or more materials or laminates of the present invention may be used in any absorbent product, and its softness and elasticity will be increased in situ after urine absorption. The products with absorbent cores of the present material or laminate are such that they will generally remain softer and more elastic over the time frame of wear with the fluff/SAP core. This capability can be advantageously used in adult underwear and special products such as pull-up underwear, mattresses, and breast pads for nursing mothers.

some embodiments of the absorbent material of the present invention are laminates. Some such laminates include: a first sublayer comprising a first sublayer of superabsorbent polymer (SAP) particles and an adhesive supporting the SAP particles in the porous matrix, the SAP particles in the first sublayer having a basis weight of 20 grams per square meter (gsm) to 130gsm, e.g., from 20gsm to 80 gsm; a second sub-layer comprising SAP particles and an adhesive supporting the SAP particles in a porous matrix, the SAP particles in the second sub-layer having a basis weight of from 20gsm to 130gsm, such as from 20gsm to 80 gsm; a third sub-layer disposed between and bonded to the first and second layers, the third sub-layer comprising a nonwoven web of wettable cellulosic fibers having a basis weight of from 2gsm to 80gsm, for example from 6gsm to 80gsm or from 6gsm to 50 gsm. The third sub-layer may comprise a hydroentangled nonwoven web, for example having a basis weight of 20gsm to 80gsm and/or comprising regenerated cellulose fibers. Alternatively, the third sub-layer may comprise a tissue, for example having a basis weight of from 15gsm to 35 gsm. Some embodiments of the absorbent laminate of the present invention further comprise: a fourth sublayer bonded to the first sublayer such that the first sublayer is disposed between the fourth sublayer and the third sublayer, the fourth sublayer comprising tissue; and a fifth sublayer bonded to the second sublayer such that the second sublayer is disposed between the fifth sublayer and the third sublayer, the fifth sublayer comprising tissue. The tissue of the fourth and/or fifth sub-layer may be creped and/or through-air dried. Additionally or alternatively, the thickness of the second sub-layer may be equal to the thickness of the first sub-layer, and/or the basis weight of the SAP particles in the second sub-layer may be equal to the basis weight of the SAP particles in the first sub-layer. Additionally or alternatively, the basis weight of the adhesive in the first sub-layer may be from 0.5 to 5gsm and the basis weight of the adhesive in the second sub-layer may be from 0.5 to 5 gsm.

Some embodiments of the absorbent laminate of the present invention have a thickness of less than 1.3 millimeters (mm). Some embodiments of the laminates of the present invention have a tensile strength of at least 40 newtons/50 mm (N/50mm) in at least one direction.

In some embodiments of the absorbent core for disposable absorbent articles of the present invention, the absorbent core comprises: one or more sheets of the absorbent laminate of one embodiment of the present invention, wherein the one or more sheets of the absorbent laminate define a plurality of layers of the absorbent laminate. For example, a single sheet of the absorbent laminate may be folded to define multiple layers of the absorbent laminate, or multiple sheets of the absorbent laminate may be stacked to define multiple layers of the absorbent laminate. Some embodiments of the absorbent core of the present invention further comprise: the absorbent laminate of one embodiment of the present invention of the add-on sheet is bonded to one of the upper outermost layers of the sub-layers of the absorbent laminate. For example, the plurality of layers of the absorbent laminate have a combined width and a combined length greater than the combined width, the combined length extending from the first end to the second end of the absorbent core, and the combined length is shorter than the combined length if an add-on sheet is present, and the add-on sheet can be disposed closer to the first end of the plurality of layers than to the second end of the plurality of layers. In some cores, the combined length of the layers of the absorbent laminate isThe additional sheet has from 50% to 70% of the absorbent laminate length. In some cores, the layers of the absorbent laminate are defined by a folded first sheet of the absorbent laminate, while the additional sheets of the absorbent laminate are not folded. Some embodiments of the cores of the present invention are configured to add 145 milliliters (mL) of water at 5X 10 when added to a 100mm by 100mm portion of the absorbent core³Pa, exhibits less than 150X 10 for the second compression cycle³A strain-based softness of Pa. Some embodiments of the core of the present invention are configured to exhibit less than 4 x 10 for a first compression cycle at a strain of 10% when 100 milliliters (mL) of water is added to a 100mm x 100mm portion of the absorbent core³A strain-based softness of Pa.

some embodiments of the disposable absorbent articles of the present invention comprise: a liquid permeable topsheet; a liquid impermeable backsheet; the absorbent core of one embodiment of the present invention is disposed between the topsheet and the backsheet. Such absorbent articles may, for example, omit or exclude the acquisition-distribution layer in addition to the absorbent core. For example, such an absorbent article may be a mattress and the absorbent core may have a width of at least 12 inches and a length of at least 18 inches.

In some embodiments of the present methods of making an absorbent laminate, the method can comprise: distributing an adhesive and superabsorbent polymer (SAP) particles on a first side of a nonwoven web of wettable cellulosic fibers, the cellulosic fibers defining a first sub-layer, such that the adhesive supports the SAP particles in a porous matrix to define a second sub-layer, the nonwoven web having a basis weight of from 6 grams per square meter (gsm) to 80gsm, the SAP particles in the second sub-layer having a basis weight of from 20gsm to 80 gsm; distributing an adhesive and superabsorbent polymer (SAP) particles on a second side of the nonwoven web of wettable cellulosic fibers such that the adhesive supports the SAP particles in the porous matrix to define a third sublayer, the SAP particles in the third sublayer having a basis weight of 20gsm to 80 gsm. Some embodiments further comprise: applying a fourth sublayer to the first sublayer such that the fourth sublayer is adhered to the first sublayer with the first sublayer disposed between the fourth sublayer and the third sublayer, the fourth sublayer comprising tissue paper, when the adhesive of the first sublayer is tacky; when the adhesive of the second sublayer is tacky, a fifth sublayer is applied to the second sublayer such that the fifth sublayer is adhered to the second sublayer, the second sublayer disposed between the fifth sublayer and the third sublayer, the fifth sublayer comprising tissue.

In some embodiments of the present methods of making an absorbent core for a disposable absorbent article, the method comprises: multiple layers of the absorbent laminate of one embodiment of the present invention are stacked. For example, multiple layers may be stacked by folding a single sheet of the absorbent laminate over itself.

Some embodiments of the disposable patient support article of the present invention comprise: a support core comprising one or more sheets of the absorbent laminate of one embodiment of the present invention, wherein the one or more sheets define a multi-layer absorbent laminate; and a liquid impermeable layer bonded to the support core. For example, a single sheet of the absorbent laminate may be folded to define a multi-layer absorbent laminate, or multiple sheets of the absorbent laminate may be stacked to define a multi-layer absorbent laminate. Some embodiments of the support core of the present invention further comprise: an absorbent laminate of one embodiment of the present invention with an additional sheet is bonded to one of the upper outermost layers of the absorbent laminate. For example, the multi-layer absorbent laminate has a combined width and a combined length greater than the combined width, the combined length extending from the first end to the second end of the absorbent core, and if an add-on sheet is present, the combined length is shorter than the combined length, and the add-on sheet can be disposed closer to the first ends of the plurality of layers than to the second ends of the plurality of layers. In some embodiments, the support core may have a width of at least 8 inches and a length of at least 8 inches. In some embodiments of the patient support article of the present invention, the support core is a first support core, the patient support article further comprising: a second support core comprising one or more sheets of the absorbent laminate of embodiments of the present invention, wherein the one or more sheets define multiple layers of the absorbent laminate, the second support core being bonded to the liquid impermeable layer and laterally spaced from the first support core.

In some embodiments of the patient support article of the present invention, the liquid impermeable layer is a backsheet and the patient support article further comprises: a topsheet; wherein the support core is arranged between the bottom sheet and the top sheet such that the bottom sheet and the top sheet form a shell in which the support core is arranged. The topsheet may be liquid permeable, such as a hydrophilic nonwoven or apertured film, or may be liquid impermeable, such as an elastic and three-dimensional polymeric film. In some configurations, the topsheet is water vapor permeable.

In some embodiments of the patient support article of the present invention, the patient support pad is configured to allow liquid to be delivered to the SAP particles prior to positioning the patient support pad under the patient. For example, the liquid impermeable layer may define a shell in which the support core is disposed, and the patient support cushion may further comprise: an inlet through which liquid may be introduced into the housing. Alternatively, the liquid impermeable layer may define a shell in which the support core is disposed, and the patient support cushion may further comprise: a container containing a volume of liquid that, when absorbed by the SAP particles, swells at least a portion of the SAP particles at least to a desired elasticity; wherein the container is disposed in the housing and is configured to rupture to release the liquid into the housing.

In some embodiments of the patient support article of the present invention, the backsheet and topsheet cooperate to define at least a portion of a pair of adult protective undergarments. For example, the protective undergarment is configured such that the support core aligns with at least a portion of one of the wearer's hips when worn by the user. In other embodiments of the patient support article of the present invention, the backsheet and topsheet cooperate to define at least a portion of the base of the mattress. In other embodiments of the patient support article of the present invention, the backsheet and topsheet cooperate to define at least a portion of: a pad having a skin adhesive configured to attach to the absorbent article, the skin adhesive configured to adhere the pad directly to the skin of a patient, and/or a pad shaped or contoured to overlie a portion of the human body, such as the heel of a patient. In other embodiments of the patient support article of the present invention, the backsheet and topsheet cooperate to define at least a portion of the chassis of the seat cushion.

Some embodiments of the method include: delivering a liquid to a support core of an embodiment of the disposable patient support article of the present invention; allowing the support core to absorb a sufficient volume of liquid to increase the compression resilience of the support core; after delivering the liquid to the support core, the patient support article is disposed between at least a portion of the patient and a surface supporting at least a portion of the patient.

The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically; two objects that are "bonded" may be unified with each other. The terms "a" and "an" are defined as one or more unless the disclosure clearly requires otherwise. The term "substantially" is defined as being large, but not necessarily completely specified (and including the specified content; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by one of ordinary skill in the art. In any disclosed embodiment, the term "substantially" may be substituted with the designation "within a percentage," where the percentage includes 0.1%, 1%, 5%, and 10%.

The term "comprising" and any form thereof, "having" and any form thereof, "including" and any form thereof, are open ended linking verbs. Thus, a device that "comprises," "has," or "includes" one or more elements possesses those one or more elements, but is not limited to possessing only those elements. Likewise, a method that "comprises," "has," or "includes" one or more steps has those one or more steps, but is not limited to having only those one or more steps.

Any embodiment of any of the materials, laminates, articles, and methods of the present invention may consist of, or consist essentially of, but does not include/comprise/have any of the described steps, elements, and/or features. Thus, in any claim, the term "consisting of or" consisting essentially of may be substituted for any of the open-ended linking verbs described above in order to alter the scope of a given claim using open-ended linking verbs.

Further, a material, laminate or article configured in a certain manner is configured in at least this manner, but it may also be configured in other manners than those specifically described.

One or more features of one embodiment may be applied to other embodiments, even if not described or illustrated, unless expressly prohibited by the nature of the disclosure or the embodiments.

Some details relating to the above-described embodiments and other embodiments are described below.

Drawings

The following drawings are presented by way of example and not limitation. For purposes of brevity and clarity, each feature of a given structure is not always labeled in every figure in which that structure appears. Like reference numerals do not necessarily denote like structure. Rather, the same reference numerals may be used to indicate similar features or features having similar functions, as may different reference numerals.

Fig. 1A depicts a bottom plan view of a prior art disposable absorbent article, particularly an adult protective undergarment, in an open configuration.

FIG. 1B depicts a perspective view of the protective undergarment of FIG. 1A in a closed configuration.

Fig. 2 depicts a schematic cross-sectional view of a first embodiment of an absorbent laminate.

Fig. 3 depicts a schematic cross-sectional view of a second embodiment of an absorbent laminate.

fig. 4A-4C depict stages of a method of making the laminate of fig. 2.

Fig. 4D depicts a further stage of the method of manufacturing the laminate of fig. 3.

Figure 5 depicts a perspective view of an embodiment of a core utilizing an embodiment of the absorbent laminate of the present invention.

fig. 6 depicts a side view of the core of fig. 4.

Fig. 7A depicts a schematic cross-sectional view of the first configuration of the core of fig. 5 taken along line 7-7 in fig. 5.

Fig. 7B depicts a schematic cross-sectional view of the second configuration of the core of fig. 5 taken along line 7-7 in fig. 5.

Fig. 8A-8C depict alternative configurations of the folded core of the present invention.

Fig. 9A and 9B depict the compression characteristics of a conventional fluff/SAP core and the core of fig. 5, respectively, after several compression cycles after fluid absorption.

Fig. 10 depicts a plan view of an embodiment of a disposable patient support pad.

Fig. 11 depicts an exploded cross-sectional view of a first configuration of the patient support pad of fig. 10.

Fig. 12 depicts an exploded cross-sectional view of a second configuration of the patient support pad of fig. 10.

Fig. 13 depicts a bottom plan view of a disposable absorbent article, particularly an adult protective undergarment including a patient support pad and in an open configuration.

Fig. 14-16 depict various views of an embodiment of the patient support pad of the present invention.

Detailed Description

Referring now to fig. 2, a first embodiment of an absorbent material is shown and designated by the reference numeral 100. As shown, the material 100 is a laminate that includes a first sub-layer 104, a second sub-layer 108, and a third sub-layer 112 disposed between the first and second sub-layers. The third sub-layer provides an intermediate base for the first and second sub-layers 104,108, which is more absorbing than the third sub-layer 112. As shown, the sublayers are arranged such that the lower side of the first sublayer 104 contacts the upper side of the third sublayer 112 and the upper side of the second sublayer 108 contacts the lower side of the third sublayer 112. In the illustrated embodiment, each sub-layer 104,108,112 has a substantially uniform thickness over its respective area. In other embodiments, the respective thicknesses of the sub-layers may vary. In some embodiments, each of the first, second, and third sub-layers 104,108,112 has a similar thickness.

In the illustrated embodiment, the intermediate substrate sub-layer, i.e., the third sub-layer 112, comprises a nonwoven web, such as a spunlace nonwoven. For example, the intermediate substrate sublayer, i.e., the third sublayer 112, can comprise wettable regenerated cellulose fibers, such as viscose orA fiber. The intermediate substrate sub-layer, i.e., the third sub-layer 112, may have a basis weight of 2 grams per square meter (gsm) to 80gsm, such as 10gsm to 30gsm, 17gsm to 23gsm, equal to 20gsm, or equal to 30 gsm. For example, an intermediate substrateThe layer may use a spunlace viscose web having a basis weight of from 20gsm to 80gsm, for example 20gsm or 30 gsm; alternatively, a spunbond viscose web having a basis weight of 6gsm to 40gsm may be used. In other embodiments, the intermediate substrate layer, i.e., the third sublayer 112, may comprise a through-air-dried (TAD) tissue having a basis weight of 10gsm to 35gsm, such as 15gsm to 30gsm, 18gsm to 28gsm, or equal to 19 gsm. In still further embodiments, the intermediate substrate layer, i.e., the third sub-layer 112, may comprise a wettable TAD or resin bonded carded polyester nonwoven, such as of the type commonly used as an acquisition distribution layer in absorbent products.

Each absorbent sublayer (first and second sublayers 104,108) comprises superabsorbent polymer (SAP) particles 116 and a binder 120 supporting the SAP particles in a porous matrix. In addition to allowing fluid to pass through the absorbent sublayer, the porous matrix also improves the compressibility and resiliency of the laminate, even when the SAP particles are dry. The basis weight of the SAP particles in each absorbent sublayer (first and second sublayers 104,108) is from 20gsm to 80gsm, such as from 35gsm to 65gsm, from 45gsm to 55gsm, or equal to 50 gsm. The basis weight of the adhesive in each absorbent sub-layer (first and second sub-layers 104,108) may be from 0.5gsm to 10gsm, such as from 0.5gsm to 5gsm, from 1gsm to 3gsm, or equal to 2 gsm. The adhesive basis weight may also be expressed as a percentage of the SAP basis weight; for example, the basis weight of the adhesive may be 2% to 6% of the basis weight of the SAP particles.

In the illustrated embodiment, the first sub-layer 104 is similar to the second sub-layer 108, including an SAP basis weight and thickness; however, in other embodiments, the second sub-layer 108 may differ from the first sub-layer 104 in any of a variety of properties, such as SAP basis weight, thickness, and the like. In one example, the first sublayer 104 may have an SAP basis weight of 40gsm and an adhesive basis weight of 1.5gsm, while the second sublayer 108 may have an SAP basis weight of 60gsm and an adhesive basis weight of 2.5 gsm. The adhesive (120) may be configured to provide adhesion while being liquid permeable to allow liquid to enter and/or pass through the absorbent sub-layers (first and second sub-layers 104, 108). For example, the adhesive may be included in the absorbent sublayer in a sufficient amount to provide the absorbent laminate 10 with minimal structural properties, e.g., an elongation at break of at least 100%, such as 600% to 1800%, to reduce gel blocking when the SAP is swollen by body fluids.

As mentioned above, the SAP material may be in the form of particles 116. Exemplary superabsorbent polymer materials can include any superabsorbent polymer particles known in the superabsorbent literature, such as described in modern superabsorbent polymer technology, f.l.buchholz, a.t.graham, Wiley. For example, the SAP particles may be spherical, spheroidal or irregularly shaped particles, such as sausage-shaped particles, or ellipsoidal particles of the type typically obtained by inverse suspension polymerization. The SAP particles may also optionally agglomerate, at least to some extent, to form larger irregular particles. In some embodiments, the SAP particles 116 may also have surface modifications, such as partial or complete surface coatings, for example to increase the hydrophilicity of the SAP particles.

The SAP particles may comprise any one or combination of a variety of materials, including organic compounds, such as crosslinked polymers. "crosslinking" is a commonly understood term and refers to any method effective to render normally water-soluble materials substantially water-insoluble but swellable. These polymers may include, for example, carboxymethylcellulose, alkali metal salts of polyacrylic acids, polyacrylamides, polyvinyl ethers, hydroxypropyl cellulose, polyvinyl morpholinone, polymers and copolymers of vinyl sulfonic acid, polyacrylates, polyacrylamides, polyvinyl pyridine, and the like. Other suitable polymers include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, and isobutylene maleic anhydride copolymers, and mixtures thereof. Organic superabsorbent materials can include natural materials such as agar, pectin, guar gum, and peat moss. Superabsorbent materials can include inorganic materials in addition to organic materials, such as absorbent clays and silica gels. Suitable examples of SAPs include T9030, T9600, T9900 and Saviva polymers from BASF corporation of Charlotte, N.C.; w211, W112A, W125, S125D, QX-W1482, QX-W1486, QX-W1504, and QX-W1505 from Shokubai corporation, japan, houston, tx.i.i.i. of texas, japan; AQUA KEEP SA50II, SA55SX II, SA60N II, SA65S, HP500E, HP600E, and HP700E from Sumitomo Seika chemicals, osaka, japan.

The SAP particles 116 may have a particle size distribution within the typical range of SAPs commercially used in disposable hygiene products. In some embodiments, the SAP particles are between about 45 micrometers (μm) and 4000 μm in size, such as between 45 μm and 2000 μm, or between 100 μm and 1000 μm. The particle size distribution of the material in particulate form can be determined, for example, by dry sieve analysis (EDANA420.02 particle size distribution). In some embodiments, at least 90%, such as at least 95% or at least 98%, of the SAP particles have a particle size diameter of 45 to 850 μm, such as 100 μm to 800 μm or 200 μm to 500 μm. When particles larger than 500 μm in size are provided less than 2% of the mass of the SAP particles, the surface roughness of the laminated pad of the present invention may in some cases be reduced considerably. Surface roughness may also be reduced when the outer layers 104,108 comprise TAD tissue, for example having a basis weight of 18 to 20 gsm.

In some embodiments, the unitary absorbent laminate and/or SAP particles may have a relatively high absorbent capacity, i.e., may have a centrifuge retention capacity or "CRC" of at least 20 grams of saline per gram of material (g/g), or at least 30g/g, tested in 0.9% saline. In some embodiments, the CRC may be up to 45g/g or 50 g/g.

in the illustrated embodiment, each of the first and second sub-layers 104,108 is bonded to the third sub-layer 112. In other embodiments, the first and second sub-layers 104,108 need not be bonded to the third sub-layer; for example, instead of a laminate construction, the first and second sub-layers may be formed separately and stacked with the third sub-layer 112 in the depicted construction but without bonding, and the sub-layers folded together, as discussed below with reference to fig. 7A and 7B, such that the folding, rather than bonding, maintains the relative positions of the sub-layers.

Fig. 3 depicts a second embodiment of an absorbent laminate 100 a. The absorbent laminate 100a is substantially similar to the absorbent laminate 100, except that the absorbent laminate 100a includes additional outer layers. Accordingly, the differences will be primarily described herein, and it should be understood that those components of the laminate 100a not labeled in fig. 3 or described herein are substantially similar to the components of the laminate 100. As shown in fig. 3, the laminate 100a includes a fourth sub-layer 124 and a fifth sub-layer 128. The fourth sublayer 124 is bonded to the first sublayer 104 such that the first sublayer 104 is disposed between the fourth sublayer 124 and the third sublayer 112, and the fifth sublayer 128 is bonded to the second sublayer 108 such that the second sublayer 108 is disposed between the fifth sublayer 128 and the third sublayer 112. In this embodiment, each outer sub-layer, i.e., the fourth and fifth sub-layers 124,128, comprises tissue paper having sufficient porosity to allow fluid to pass through the tissue paper into the absorbent sub-layer, e.g., creped or through-air dried tissue paper. The tissue can have a basis weight of 10gsm to 25gsm, such as 15gsm to 20gsm, or equal to 17 gsm. One example of a tissue suitable for the outer layer (i.e., the fourth and fifth sub-layers) in at least some embodiments is a 17-gsm 3995 machine-creped tissue from Dunn paper. In other embodiments, each of the outer sub-layers (i.e., the fourth and fifth sub-layers 124,128) includes a nonwoven material. In one example of a material having the configuration of fig. 3, the first sub-layer 104 comprises a spunlaced nonwoven of viscose fibers having a basis weight of 20gsm, each of the second and third sub-layers 108,112 comprises 50gsm of BASF T9900SAP particles and 2gsm of Savare E60W adhesive, and each of the fourth sub-layers 104, the fifth sub-layers 124,128 comprises 17gsm 3995 machine-creped tissue from Dunn paper, such that the entire laminate is extremely flexible and has a basis weight of 158gsm and is thinner than 1.5 millimeters (mm).

in some embodiments, the outer sub-layers, i.e., the fourth and fifth sub-layers 124,128, may comprise TAD tissue, standard tissue, spunbonded synthetic nonwoven, carded synthetic nonwoven, or apertured film. For example, in one example, the fourth sub-layer 124 comprises TAD tissue, the fifth sub-layer 128 comprises standard tissue, and the third sub-layer 112 comprises spunlace nonwoven or TAD tissue. In still further embodiments, the laminate 100a may include additional inner substrate layers and SAP/adhesive layers. For example, the laminate 100 may, in some cases, include two or more third sub-layers 112 of hydroentangled or TAD tissue having a corresponding number of SAP/adhesive sub-layers, similar to, for example, the sub-layers 104, 108.

In the embodiment of fig. 3, the basis weight of the SAP in the sub-layers 104 and 108 may be selected for a particular core configuration. For example, the sub-layers 104 and 108 may each include 50gsm, 75gsm, 100gsm, or 150gsm of SAP. Once the basis weight of the SAP in each sub-layer 104 and 108 is known, the number of layers of the laminate can be selected to obtain the desired total basis weight of SAP in the absorbent core. For example, when a total basis weight of SAP of 300gsm is desired, three layers each having a total of 100gsm laminate with 50gsm SAP in each sub-layer 104,108 may be used; two layers each having a total of 150gsm laminate may be used, with 75gsm SAP in each sub-layer 104, 108; alternatively, one layer having a total of 300gsm laminate with 150gsmSAP in each sub-layer 104,108 may be used. Conversely, if a total SAP basis weight of 200gsm is desired, two layers of a laminate each having a total of 100gsm may be used, with 50gsm SAP in each sub-layer 104, 108; one ply of laminate having a total of 200gsm may be used, with 100gsm of SAP in each sub-layer 104, 108. Qualitative observations of partially hydrated TIP cores indicate that elasticity and softness decrease with increasing basis weight of the individual SAP layers in the laminate, and decrease with decreasing number of layers of the absorbent laminate in the core.

Fig. 4A-4C depict various stages of a method of manufacturing the laminate 100 of fig. 2. As shown in fig. 4A, the process begins with an intermediate base sub-layer, the third sub-layer 112.

as shown in fig. 4B, the first sublayer 104 is added to the first side of the third sublayer 112. For example, adding the first sub-layer 104 may include distributing an adhesive on the first side of the third sub-layer 112, such as by spraying, and air laying superabsorbent polymer (SAP) particles in contact with the adhesive on the first side of the third sub-layer 112 to define the first sub-layer 104. The adhesive on the first side of the third sub-layer 112 may, for example, comprise foam. In some embodiments, the adhesive and SAP of each sub-layer are applied to the nonwoven web as a mixture.

As shown in fig. 4C, the second sublayer 108 is added to the second side of the third sublayer 112. For example, adding the second sub-layer 108 may include distributing an adhesive on the second side of the third sub-layer 112, such as by spraying, and air laying superabsorbent polymer (SAP) particles in contact with the adhesive on the first side of the third sub-layer 112 to define the second sub-layer 108. The adhesive on the second side of the third sub-layer 112 may, for example, comprise foam. As shown in fig. 4C, because the SAP particles are air laid in this embodiment, the third sub-layer 112 is flipped over so that the second side of the third sub-layer (112) faces upward to receive the adhesive and the SAP particles. In some embodiments, the adhesive and SAP of each sub-layer are applied to the nonwoven web as a mixture.

In the method of making the laminate 100 of the present invention, the SAP particles may be conventionally mixed with hot melt adhesive fibers of the type produced by commercially available meltblown-type die heads widely used in the manufacture of disposable absorbent articles. The hot melt adhesive can be any adhesive, such as a pressure sensitive adhesive, suitable for high speed manufacture of disposable absorbent articles, having the necessary rheology to form the viscose fibers in a commercially available meltblown system. In one aspect, the hot melt adhesive can be a tacky pressure sensitive synthetic rubber based adhesive such as, but not limited to, styrene-butadiene-styrene (SBS) or styrene-isoprene-styrene (SIS) block copolymer based adhesive types. The hot melt adhesive fibers must be added in an amount sufficient to produce a laminate having sufficient strength to withstand the mechanical forces applied during the conversion process, but not so much as to interfere with the swelling of the SAP particles. In some embodiments, the glass transition temperature of the adhesive is above room temperature, i.e., 73 degrees, to maintain stability while maintaining flexibility. Examples of suitable commercially available adhesives are HBFuller NW 1023 AAZP and Savare E60W. In some embodiments, each absorbent sublayer, i.e., the first and second sublayers 104,108, is formed by sequentially distributing adhesive, air laying the SAP particles, dispensing the adhesive, and air laying the SAP particles in multiple steps to form the respective absorbent sublayer.

Fig. 4D depicts another stage of the method of manufacturing the laminate 100a of fig. 3. As shown, the outer sub-layers (i.e., the fourth and fifth sub-layers 124,128) are added to the outer sides of the respective absorbing sub-layers (i.e., the first and second sub-layers 104, 108). In some embodiments, before the adhesive of that sub-layer has completely cooled, tissue paper is added and pressure is applied to adhere the tissue paper to the respective absorbent sub-layer (i.e., first or second sub-layer 104, 108). In other embodiments, the adhesive is distributed and the SAP particles are air-laid to the respective tissue sub-layer (i.e., the fourth or fifth sub-layer 124,128), and then the tissue sub-layer and the absorbent sub-layer positioned relative to the intermediate substrate layer (i.e., the third sub-layer 112) are combined.

Reference is now made to fig. 5 and 6; fig. 5 depicts a perspective view of an embodiment of a core 200 utilizing an embodiment of an absorbent laminate of the present invention, such as laminate 100 or laminate 100 a; and figure 6 depicts a side view of the core 200. The core 200 comprises one or more sheets of laminate, such as sheet laminate 100 or sheet laminate 100a, defining a plurality of layers 204 of absorbent laminate. For example, in the illustrated embodiment, the monolithic laminate 100 is folded to define an upper layer 204a, a middle layer 204b, and a lower layer 204c of the absorbent laminate. In other embodiments, multiple sheets of the absorbent laminate are stacked to define a multi-layer absorbent laminate, e.g., each sheet defining a different layer. Although the depicted embodiment includes three primary layers of laminate, other embodiments may include any number of laminate layers.

In the embodiment shown in fig. 5 and 6, the core 200 further comprises an additional component 208 of an absorbent laminate, in particular the laminate 100 as shown, which is bonded to one of the upper outermost layers of the absorbent laminate, in particular the upper layer 204 a. As shown in fig. 5, the core 200 (i.e., the layers 204a, 204b, 204c of the absorbent laminate) has a combined width "W" and a combined length "L" that is greater than the combined width and extends from the first end 212 of the core 200 to the second end 216 of the core 200. In this embodiment, the appendage 208 has a length 220 that is shorter than the combined length "L" and is closer to the first end 212 than the second end 216.

the core 200 may be manufactured by stacking a plurality of layers 204a, 204b, 204 c. In embodiments where a single sheet of absorbent laminate or material defines multiple layers, the layers may be stacked by folding the sheet of absorbent laminate upon itself. For example, fig. 7A depicts a first configuration in which the sheet of absorbent laminate is folded in a C-fold configuration. Fig. 7B depicts a second configuration in which the sheet of absorbent laminate is folded in a Z-folded configuration. The multiple cover layers of the absorbent laminate define transverse channels between the layers that allow fluid to flow transversely between the layers, for example, to distribute fluid over a relatively large area of each layer for absorption. In addition, the relative position of the SAP particles 216 of adjacent layers at the interface between the layers may affect the surface topography of each sheet and may result in a relatively random distribution of laterally extending valleys and corresponding micro-channels to further promote fluid dispersion between adjacent absorbent laminate layers. The use of highly crosslinked SAP with higher gel hardness or SAP particles with larger particle size can increase the surface topography of adjacent hydration layers, thereby facilitating this type of channeling.

The depicted core 200 may be used in various absorbent articles, such as an undergarment 10 in place of the core 74, which includes a liquid permeable topsheet; a liquid impermeable backsheet; and a core 200 disposed between the topsheet and the backsheet. In some such articles, the article does not include a separate ADL, other than the core (200). In one example of such an absorbent article, the absorbent article is a mattress and the core 200 has a width "W" of at least 12 inches and a length "L" of at least 18 inches. In some embodiments of absorbent articles comprising the core 200, an outer sheet, such as a topsheet, having antimicrobial properties and/or a smooth or lubricious surface to reduce friction is used on the surface of the product that is in contact with the skin.

Fig. 8A, 8B and 8C depict alternative embodiments 200a, 200B, 200C of the folded core of the present invention. In each of these embodiments, the core comprises a first sheet 224 of the laminate of the present invention, such as laminate 100 or laminate 100a, folded to define a plurality of layers, and a second component 228 of the laminate of the present invention, such as laminate 100 or laminate 100a, unfolded. In the core 200a, a first sheet 224 of the laminate is folded in a C-fold configuration, wherein the transverse portions of the sheet are folded over each other such that each of the three layers has a substantially equal width. In the core 200b, a first sheet 224 of laminate is folded such that the transverse portions of the laminate are first folded inwardly in two steps to define a central channel between two separate transverse zones, wherein the sheet defines a three-layer laminate. In this embodiment of fig. 8B, each lateral region is folded in a C-folded configuration, but in other configurations, each lateral region may be folded in a Z-folded configuration. The core 200c is similar to the core 200b in that the laminate is folded to define two separate transverse sections, but differs from the core 200b in that each transverse section is folded only once to define a two-layer laminate. In these embodiments, the length 232 of the first sheet 224 is less than, for example, 50% to 70% of the length 236 of the second sheet 228. In other embodiments, the second sheet 228 may or may not be folded to define multiple layers of the laminate such that the first sheet 224 defines the entire area of the core.

Reference is now made to fig. 9A and 9B; FIG. 9A depicts the compression performance of a conventional fluff/SAP core over several compression cycles after fluid absorption; and figure 9B depicts the compression characteristics of the core 200 over several compression cycles after fluid absorption. As shown in fig. 9A, a conventional fluff/SAP core recovers only about two-thirds of its original thickness upon release of a compressive force. In contrast, as shown in fig. 9B, upon release of the compressive force, the core 200 recovers more than 90% of its original thickness. After the first compression cycle, the pad consisting of fluff/SAP becomes stiffer. This is illustrated by the increase in the slope of the compression force curve in fig. 9A. In contrast, the "TIP" core in fig. 9B remains soft for three compression cycles. The slope of the compressive force curve at a particular stress or strain, expressed as the compressive modulus, is a measure of the softness of the partially hydrated core. The lack of elasticity and softness of the partially hydrated fluff/SAP pad may be due to the redistribution of the fluff/SAP in the X-Y plane of the pad, leaving permanent depressions at the compression points and ridges of material around them. After repositioning body weight, these hard material ridges can create stress concentrations against the skin and promote the formation of pressure ulcers, particularly in the area of bony prominences. In contrast, the material of the present invention may exhibit improved elasticity due to a combination of, for example, SAP gel strength properties (as indicated by CRC), SAP basis weight per layer and SAP particle size distribution. In the multi- (sub-) laminar laminates of the present invention, the inner substrate or non-SAP sublayer may reinforce the location of the SAP particles, stabilizing the swollen gel during compression, thereby maintaining a soft, resilient mat during repeated compression cycles. For example, the internal hydroentangling and/or the surface texture of the TAD tissue layer may resist the spreading or lateral movement of the SAP particles, thereby promoting elastic compression of the SAP particles.

A partially hydrated "TIP" core including a T9900SAP is shown in FIG. 9B, shown when in"Strain-based" softness for the second compression cycle when 100ml water is added to a 100mm x 100mm core section at 0.9 x 10³Results of 10% strain at Pa. The fluff/SAP core shown in FIG. 9A, containing about 20% SAP, has an 8X 10³Pa "strain-based" softness. The "TIP" core, having the same composition as in fig. 9B, but made with HP700E SAP was not as soft. It has 34 x 10 in the second compression cycle³Pa's "strain-based" softness is not as good as a "TIP" core made with T9900 SAP. However, the elasticity of the "TIP" core made with the P700E SAP after the first compression was 91%, almost as good as the TIP core made with the T9900 SAP.

Reference is now made to fig. 10 and 11; fig. 10 depicts a plan view of an embodiment 300 of a disposable patient support pad; and fig. 11 depicts an exploded cross-sectional view of the patient support pad 300. In this embodiment, the pad 300 includes a support core 304 and a layer 308 bonded to the support core 304. The support core 304 is similar in some respects to the core 200, the support core 304 comprising one or more sheets of the absorbent laminate of the present invention, e.g., laminate 100 or laminate 100a, which define multiple layers of the absorbent laminate, similar to, e.g., layers 204a, 204b, 204 c. In the illustrated embodiment, a single sheet of the absorbent laminate may be folded to define multiple layers of the absorbent laminate; however, in other embodiments, multiple sheets of the absorbent laminate are stacked to define multiple layers of the absorbent laminate, e.g., each sheet defines a different layer. Additionally, similar to the core 200, some embodiments of the support core 304 further include additional absorbent laminates, e.g., laminate 100 or 100a, bonded to the upper outermost layer of the sub-layers of the absorbent laminate. In the embodiment shown, where the disposable support article is a patient support cushion such as a mattress or seat cushion, the support core 304 has a width "W" of at least 8 inches and a length "L" of at least 8 inches.

In the embodiment shown in fig. 10 and 11, the pad 300 further includes a second layer 312 bonded to the first layer 308 to define a pocket in which the support core 304 is disposed. In this embodiment, the first layer 308 can be considered a topsheet because it defines the body-facing surface of the pad, and the second layer 312 can be considered a backsheet because it defines the outer surface of the pad that faces away from the patient or user when the pad is in use. In some configurations, the first layer or topsheet 308 is treated or finished to exhibit certain properties, for example, reduced friction, increased hydrophilicity, and/or increased antimicrobial properties relative to the untreated or unpolished material of the layer. In the illustrated embodiment, the support core 304 may be wetted with a liquid to swell the SAP particles prior to placing the support cushion 300 under the patient. Specifically, pad 300 is configured to allow liquid to be delivered to the SAP particles prior to positioning the pad under the patient. For example, as shown in FIG. 10, the illustrated embodiment of pad 300 includes a container 316, such as a rupturable pouch, disposed within the housing and retaining a volume of liquid that swells at least a portion of the SAP particles to have at least a desired elasticity when absorbed by the SAP particles of support core 304; and the container is configured to rupture to release the liquid within the housing to swell the SAP particles. Such a rupturable capsule may be similar to, for example, those in chemical cold packs known and used for emergency purposes, wherein a liquid is released to initiate an endothermic chemical reaction and reduce the temperature of the cold pack. In other embodiments, the pad 300 includes an inlet, such as a sealable inlet, through which liquid can be introduced into the housing. The support core may be secured to the first layer 308 and/or the second layer 312 by a foamed adhesive, which may further increase the degree of resiliency for the pad 300 and may further separate the support core from the respective layer to reduce the likelihood that liquid may travel to and through the respective layer and be perceived by a user as being wet.

In the embodiment shown in fig. 10 and 11, both the first layer 304 and the second layer 308 are liquid impermeable, such that the pad 300 will retain liquid even under pressure due to the weight of the patient, e.g., to prevent liquid from penetrating the first layer at the skin interface with the patient's skin. In some embodiments, the topsheet 308 comprises a three-dimensional polymeric film, such as a film that is also elastic, which can flex to accommodate shear forces due to compression of the support core 304 in use. In other embodiments, the first layer or topsheet 308 comprises a breathable material, such as a breathable backsheet useful in disposable absorbent articles. For example, the first layer or topsheet 308 can comprise, for example, an inner liquid impermeable film and an outer nonwoven sheet that can be a nonwoven. A "film" is a film-like layer of material formed from one or more polymers that does not have a form consisting essentially of a network of fibers and/or other fibers. In some embodiments in which the first layer or topsheet 308 is breathable, for example, the inner liquid impermeable film of layer 308 can comprise a breathable film. The terms "breathable", "breathable film", "breathable laminate" or "breathable outer cover material" or "breathable backsheet" refer to a film, laminate or outer cover material having a water vapor transmission rate ("WVTR") of at least about 300 grams per square meter per 24 hours. Breathable materials generally rely on molecular diffusion of vapors and are substantially liquid impermeable. The breathability of layer 308 may allow some vapor to diffuse through the layer to reduce moisture build-up at the skin interface between the patient and pad 300. In other embodiments, the first layer or topsheet 308 comprises a liquid permeable material, such as an apertured film or a hydrophilic nonwoven having sufficient porosity; for example, the SAP particles in the support core 304 may be sufficiently wet to swell and impart some elasticity, but not so much that the SAP particles are fully saturated, and thus may absorb additional body fluids from a patient supported by the support cushion.

Some embodiments of the patient support cushion of the present invention further comprise a second support core 304. For example, the second support core may be disposed on top of or below the first support core in a stacked configuration, or may be laterally spaced apart such that the first support core is configured to be disposed below a first portion of the patient, e.g., a first heel, and the second support core is configured to be disposed below a second portion of the patient, e.g., a second heel. In such embodiments, the patient support cushion may define a separate shell for the support core, or may define a single shell in which two support cores are provided, e.g., adhered or otherwise bonded to the first layer or top sheet 308.

In its simplest form, other embodiments of the pad 300 may omit the second or backsheet 312; in such a configuration, the pad may be placed with the support core 308 facing an impermeable surface, such as a solid chair surface, and the first layer or top sheet 308 provides a barrier facing the patient without having to prevent moisture from the support core from contacting or penetrating to some extent onto the support surface. Such an embodiment may be useful, for example, where such buffering may be required for temporary or short-term use, but the time of use is short enough and/or other circumstances make the additional cost of a complete housing unreasonable.

Fig. 12 depicts an exploded cross-sectional view of a second configuration 300a of the patient support pad of fig. 10. The pad 300a is similar in several respects to the pad 300, the main difference being that the pad 300a includes the absorbent core 200 in addition to the support core 304 and defines two compartments for the respective cores. More specifically, the pad 300a includes an intermediate layer 320 that divides the housing into two compartments. In this embodiment, the first layer 308 comprises a liquid permeable topsheet and the intermediate layer 320 comprises a liquid impermeable material to define a first compartment in which the absorbent core 200 is disposed to receive bodily fluid exudates from a patient disposed on the pad 300 a. Both the intermediate layer 320 and the backsheet 312 are liquid impermeable to contain liquid in the compartment in which the support core 304 is disposed. Like pad 300, pad 300a is configured to allow liquid to be delivered to support core 304 prior to positioning pad 300a under a patient, for example, through reservoir 316 or a separate inlet as described above. In some embodiments, the intermediate layer 320 comprises a three-dimensional polymer film, such as a film that is also elastic, that can flex to accommodate shear forces generated by compression of the support core 304 in use. In this embodiment, the absorbent core 200 may perform the conventional absorbent function of a conventional mattress, while the support core 300 may independently perform the support function of a conventional patient support cushion or seat cushion.

Fig. 13 depicts a bottom plan view of a disposable absorbent article 10a, particularly an adult protective undergarment, including a patient support pad 300 and in an open configuration. The undergarment 10a is substantially similar to the undergarment 10, except that the patient support pad 300 is similar to those described above, but sized for the depicted configuration. In this embodiment, the patient support cushion 300 is shaped to extend around the hips of the wearer to provide cushioning to distribute forces and reduce local maxima of TIP, thereby reducing the likelihood of pressure sores. In other embodiments, additionally or alternatively, the patient support pad 300 may be sized and/or shaped to cover the buttocks of the patient.

in use, liquid may be delivered to the support core 304 of the patient support cushion 300 or 300a prior to placing the patient support cushion 304 under a portion of the patient and allowing the support core to absorb a sufficient volume of liquid to increase the compression resilience of the support core. The liquid used to swell the SAP particles may include water, saline, and the like; also, in some instances, such liquids include antimicrobial additives and/or skin care additives, such as vitamin E and the like.

Fig. 14-16 depict various views of an embodiment of the patient support pad of the present invention. More specifically, fig. 14 depicts a top view of a patient support pad 300b sized and/or contoured to cover a portion of a patient's body, such as the buttocks, shoulders, elbows, or head. Pad 300b is similar in structure to pad 300 of fig. 11. In addition, the pad 300a includes an adhesive 324 configured to bond the pad to a user. For example, the adhesive 320 may include a skin adhesive configured to adhere the pad directly to the skin of the patient, or an adhesive 324 may be configured to adhere the pad to the inner surface of the clothing or absorbent article of the patient. Fig. 15 depicts a pad 300c that is similar in structure to pad 300b, except that pad 300c is contoured to cover the sacrum or heel of the patient. Fig. 16 depicts a cross-sectional view of an alternative configuration for any of the pads 300, 300a, 300b, and 300 c. In the configuration of fig. 16, the support core 304a comprises layers of an absorbent laminate of the present invention, e.g., the layers are not bonded to each other, thereby allowing sliding relative to each other. In the depicted embodiment, the support core spans only a particular area of the pad, e.g., less than 50% of the overall lateral dimension of the pad.

Examples of the invention

Several samples of the laminate shown in figure 3 were prepared and tested, with the materials and basis weights listed in table 1 below.

table 1: sample laminate structure

	Sample 1	Sample 2	sample 3
				Component part	Basis weight	Basis weight	Basis weight
Thin paper surface (124)	17gsm	17gsm	17gsm
				Adhesive (120)	2gsm	2gsm	4gsm
SAP(116)	50gsm	56gsm	80gsm
				Nonwoven (112)	20gsm	20gsm	20gsm
Adhesive (120)	2gsm	2gsm	1gsm
				SAP(116)	50gsm	56gsm	21gsm
thin paper surface (128)	17gsm	17gsm	17gsm
				Total of	158gsm	170gsm	160gsm

The tissue paper used for the fourth and fifth sub-layers 124,128 is a 17 grams per square meter (gsm)3995 tissue paper from Dunn paper. The adhesive (120) in the first sub-layer 104 and the second sub-layer 108 is E60W from Savare specialty adhesives. The SAP (116) in the first sublayer 104 and the second sublayer 108 is T9900 from BASF. The nonwoven fabric for the sub-layer 112 is a 20gsm, 100% viscose spunlace nonwoven from the Jacob-Holm Group. Although the SAP and adhesive are listed separately, the SAP and adhesive are applied as a mixture for each sub-layer 104, 108.

Certain tests were also performed on each of these three samples to determine the mechanical properties of their respective structures. The results of these tests are listed in table 2 below.

Table 2: sample laminate test data

Tensile strength was measured dry in the Machine Direction (MD) using a Zwick Model Z005 material test frame with TestXpert software. Specifically, a50 mm x 240mm sample of each sample laminate was cut and clamped into the jaws of a tensile tester with the 240mm dimension oriented parallel to the direction of stretching of the tensile tester. The jaws were then moved apart at a rate of 100mm per minute until the sample broke or until a jaw spacing of 500 mm was reached and newton's force was recorded at the point of sample breakage or the force required to separate the jaws further down to 95% or less of the maximum force. Caliper measurements were measured using an Emveco electronic micromodel 200A at a pressure of 0.0725 pounds per square inch (psi).

Core sample and test

Core samples using the laminate samples described above were constructed and tested for collection and run-off performance. For comparison, conventional fluff/SAP diaper cores were subjected to similar acquisition and runoff performance tests.

For collection testing, reference is made to the fluid inlet return and evaluation apparatus shown and described in FIG. 5 and FIG. 6 of U.S. Pat. No.5,147,343 to Kellenberger, column 10, lines 21-65, which is incorporated herein by reference. The sample core or diaper was placed on a 3 inch x 6 inch overhead platform according to the position described in the Kellenberger patent to center the metering tube on the product target. A880 g cap with a 5.1cm Inner Diameter (ID) metering tube was placed on the core over the alignment pins that centered the metering tube on the raised platform.

a 100 milliliter (mL) dose of 0.9% saline (12 drops of McCormick Green food color per 20 liters of saline) was added to a metering tube with a graduated cylinder and the time required to discharge the liquid into the wick was recorded as the time of collection. After 30 minutes, remove the top of the device, place a stack of 10 Whatman No.4, 70 mm diameter filter paper circles on the core target, and place a 0.7psi weight on top of the filter paper circles for exactly 2 minutes. The filter paper circle was then removed and weighed, and the liquid absorbed by the filter paper was recorded as rewet. The metering plate was then replaced and the procedure repeated with a second 100mL dose of saline. This test was performed three times for each core sample and diaper core, and the average value and standard deviation of each core sample or diaper core were calculated.

Core samples were prepared by stacking two 200mm x 300mm sample 1 laminates (as described above) and folding them longitudinally to prepare 100mm x 300mm cores with 4 layers of material. A15 gsm surfactant treated spunbond polypropylene diaper topsheet was placed on top of the folded core sample to prevent liquid from interfering with the surface of the core. The first control/comparative variant was prepared by cutting the elastic around the periphery of the core of a large-sized conventional fluff/SAP core diaper to allow the diaper to lay flat in the apparatus. A second control/comparative variant was prepared by carefully removing the nonwoven acquisition-distribution layer (ADL) using a heat gun to separate the ADL from the topsheet of a similarly sized large conventional fluff/SAP core diaper, after which the topsheet replaced the core. All three variants were tested according to the procedure described above. The collection time data is recorded in table 3 below. Particularly after the sample core is wetted (after the first acquisition), the sample core (with ADL alone) exhibits an acquisition time consistent with conventional diaper cores with discreet ADLs. The caliper of the sample core is also significantly smaller relative to the conventional core. Specifically, a conventional fluff/SAP diaper core has a thickness of about 5.4mm in the target area, while a sample core has a thickness of about 3.7mm in the target area.

Table 3: collecting test data

for the acquisition test-the effect of capillary properties of the core is intended to be accounted for to allow liquid to diffuse through the core and prevent it from leaking before the SAP has had time to absorb-a 45 degree run-off set is constructed. The apparatus includes a sample support surface at a 45 degree angle relative to a horizontal support surface. The sample support surface was sized to support a 150mm by 100mm core sample at a 45 degree incline, while a metering tube with an ID of 1/8 inches was centered over the sample, with the discharge of the metering tube set at 25mm above the inclined sample support surface. The 150mm dimension of the sample was oriented along the bevel and the sample was held on the sample support plate by six sharp pins projecting outwardly from the sample support surface. The sample is placed on the bottom row of pins to position it relative to the metering tube, and the remaining pins pierce the sample core, holding it in place along the sample support surface. In operation, the metering tube dispenses 50ml of 0.9% saline from the funnel using gravity feed in about 6 seconds. Any metered liquid that is not absorbed by the sample flows down the sample support surface to a collection trough at the bottom of the sample support surface. The collection trough is also angled to direct liquid into a small beaker to collect as run off. The runoff was then poured from the beaker into a 100ml measuring cylinder and the runoff was recorded.

The sample core was constructed by stacking 4 150mm x 100mm sample laminates (as described above). These four layers were then wrapped in a 15gsm spunbond nonwoven diaper topsheet and the topsheet material was stapled to the periphery to prevent leakage of the laminate when wet.

For comparison, a large-size, conventional fluff/SAP core diaper was cut transversely 150mm below the front waist of the core. Scissors are used to cut the elastic material from the periphery of the core, but to keep the sides bonded to contain the core when wet. The core was then rolled back into the cross cut edge and the backsheet was stapled to the topsheet to retain the core material after wetting.

To five of each sample core and regular diaper core (N ═ 5) 50mL of saline was given, run off was recorded, then each was allowed to equilibrate for 30 minutes before the subsequent times, and the process was repeated five (5) times. The measured run-off data are shown in table 4 below. As shown, the sample core exhibited run-off comparable to the first conventional diaper, rather than a thinner core as would normally be expected, e.g., a pulp-free core exhibited poor run-off results.

Considering the small void volume of the example 1 core, it is difficult to obtain a runoff value similar to that of a thicker conventional fluff SAP diaper due to its thinness.

Table 4: runoff test data

Additional core samples and elasticity/softness tests

Several samples of the laminate shown in figure 3 were prepared and tested, with the materials and basis weights listed in table 5 below. To investigate the effect of SAP-type and intermediate substrate (112) materials on elasticity (caliper recovery after compression) and softness (compression modulus, K), four additional sample laminates were made using two different SAPs and two different intermediate substrates, as listed in table 5.

table 5: additional sample laminate Structure

the tissue paper used for the fourth and fifth sub-layers 124,128 is a 17 grams per square meter (gsm)3995 tissue paper from Dunn paper. The adhesive (120) in the first sub-layer 104 and the second sub-layer 108 is E60W from Savare specialty adhesives. Although the SAP and adhesive are listed separately, the SAP and adhesive are applied as a mixture for each sub-layer 104, 108.

From these four additional sample laminates, four additional core samples were formed in the manner described above, with three layers of the respective sample laminate wrapped in a nonwoven topsheet material.

The elasticity and softness of the absorbent core were measured using a compression/extension device of a 5943 type tensile strength tester equipped with a 1kN compression/extension load cell. The test sample was constructed using 100mm x 100mm portions of the absorbent core (fluff/SAP or layers of laminate) attached to a typical polymeric backsheet material by a light application of hot melt adhesive. A 12gsm polypropylene topsheet was placed on the surface of the absorbent core. The test samples were uniformly hydrated and equilibrated with 100mL or 145mL of tap water for 30 minutes at 22 ℃, 50% relative humidity prior to compression. After equilibration, the sample was placed between two tensile tester compression plates (150 mm diameter) that were initially separated by a distance greater than the swollen thickness of the sample. The lower plate is rigidly attached to the base of the tensile strength tester apparatus and the upper plate is attached to the compression load cell. The sample was subjected to three consecutive compression/decompression cycles at a coupling speed of 10 mm/min. The maximum compression is set to a compression force of 20N or 50N. The thickness of the sample is defined as the interval of compressing the plates when the sample is compressed with a force of 2N.

The elasticity and softness associated with the absorbent core of the absorbent product were determined by adding 100mL of tap water to the sample and cycling to a maximum compression force of 20N. Elasticity is defined as the percent recovery of the thickness of the sample after the first compression cycle. Higher recovery values are generally considered better. For example, if the sample recovers to its original swollen thickness after one compression cycle, the recovery is 100%. The "strain-based" softness metric is defined as the compressive modulus (i.e., the slope of the compressive force versus strain curve in Pa) at 10% compressive strain in the second compression cycle. Strain is the reduction in thickness in compression divided by the sample thickness at the beginning of the compression cycle. A smaller value of the compression modulus indicates a softer core.

The elasticity and softness associated with the absorbent core of the disposable patient support article were determined by adding 145mL of tap water to the sample and cycling to a maximum compressive force of 20N or 50N. Elasticity is defined as the percent recovery of the thickness of the sample after the first compression cycle. The "strain-based" softness measurement is defined as the compressive modulus at a maximum force of 20N or 50N (i.e., at 2X 10³Pa or 5X 10³Pa maximum pressure, 100mm x 100mm sample).

The elasticity and softness of the middle substrate of four samples made with T9900SAP or HP700E SAP and 28gsm viscose spunlace or 21gsm through-air-dried tissue were measured. Specifically, for flexibility and softness, each core section was hydrated with 145mL of water, and then subjected to multiple cycles of compressive force between 2N and 50N in a 100mm by 100mm area. After each compression cycle, the percentage of the original thickness was measured while the compressive force was removed. The results of these tests are listed in table 6 below.

The hydrated thickness of the sample core made with the laminate containing the T9900SAP was 28% -48% greater than the hydrated thickness of the sample core made with the HP700E SAP. The HP700E SAP has a finer particle size distribution than the T9900SAP, providing a higher packing density for the HP700 ESAP. Another difference between SAPs was their centrifuge retention capacity or CRC, 33g/g for T9900SAP and 47g/g for HP700E SAP, as determined by the WSP 241.2 method.

For a sample core with a three-layer absorbent laminate, the elasticity (i.e., caliper recovery after cycles 1,2, and 3) of all four possible combinations of SAP and the intermediate substrate (112) was comparable. The first compression cycle has an elasticity in the range of 87% to 89% and the third compression cycle has an elasticity in the range of 84% to 88%. All sample cores provided better elasticity values than achieved with fluff/SAP cores. Specifically, when compressed to 2 × 10³Pa (0.3psi) to 5X 10³The partially hydrated fluff/SAP core typically has an elasticity of less than 70% at Pa (0.7 psi).

For sample cores made with T9900SAP, softness (i.e., 5X 10)³Compressive modulus of Pa) is low. Specifically, the compressive modulus of the partially hydrated sample cores containing the T9900SAP was at 5X 10³Pa is 72X 10³Pa. In contrast, the softness of a partially hydrated fluff/SAP core is typically greater than 70X 10 under such pressure³Pa. Comparable softness values were obtained for sample cores made using laminates containing a hydroentangled cloth and an inner tissue layer.

Table 6: elasticity and softness data

The above specification and examples provide a complete description of the structure and use of the illustrative embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. Therefore, the various illustrative embodiments of the method and system are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alterations falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiments. For example, elements may be omitted or combined into a single structure, and/or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any other examples described to form other examples having comparable or different properties and/or functionalities, and to address the same or different issues. Similarly, it is to be understood that the above advantages and advantages may relate to one embodiment or may relate to multiple embodiments.

The claims are not intended to be inclusive and should not be interpreted as including means-plus or step-plus-function limitations unless such limitations are expressly set forth in a given claim using the phrases "means-plus" or "step-plus" respectively.