Patent Application
20170258649
The present disclosure is directed to multi-component topsheets having three-dimensional materials. The present disclosure is also directed to absorbent articles having multi-component topsheets having three-dimensional materials.
A need exists for improved materials and improved materials for use in absorbent articles. In certain instances, a need exists for improved nonwoven materials or laminates of nonwoven materials or laminates comprising nonwoven materials that look and feel soft, have improved dryness, and have improved bowel movement (“BM”), or other bodily fluid, absorbency, retention, and reduced run-off. In particular, a need exists for improved nonwoven materials having three-dimensional features formed therein to provide improved softness, dryness, and BM, or other bodily fluid, absorbency, retention, and reduced run-off, as well as providing visual signals of softness, dryness, and BM, or other bodily fluid, absorbency, retention, and reduced run-off. These improved nonwoven materials with three-dimensional features are sometimes expensive to manufacture. As such, a need exists to reduce the end cost of the improved nonwoven materials having three-dimensional materials in absorbent articles.
The present disclosure provides improved three-dimensional nonwoven materials having improved softness, dryness, and BM, or other bodily fluid, absorbency, retention, and reduced run-off, as well as a visual signal of the same. The three-dimensional nonwoven materials may comprise apertures and create significant void volume for better absorbency, retention, and reduced run-off of BM and other bodily fluids. The apertures allow BM, and the other bodily fluids, to quickly penetrate into absorbent articles, while the increased void volumes allow for better BM, or other bodily fluid, retention. Further, the increased void volumes reduce the spread of BM, and other bodily fluids, once captured, thereby providing reduced run-off benefits and reduced BM leakage. Additionally, the three-dimensional materials of the present disclosure may act to wipe BM, or other bodily fluids, off of skin of a wearer, during wearer movement. Lastly, the three-dimensional nonwoven materials of the present disclosure provide high surface areas and contact with the skin, to entangle BM, or other bodily fluids, and at least reduce BM, or other bodily fluids, from sticking in the skin. As referenced above, these improved nonwoven materials having three-dimensional features may be expensive. As such, absorbent article manufacturers may want to reduce the amount of these materials used. The present disclosure solves this problem by providing the improved nonwoven materials having three-dimensional features only in a middle strip of a topsheet, with the two outer strips being cheaper and lower basis weight materials, such as lower basis weight nonwoven materials. The improved nonwoven materials being positioned in a middle strip (higher basis weight) and lower basis weight nonwoven materials being positioned in outer strips in a topsheet may maintain a majority of excreted bodily fluid proximate to a central longitudinal axis of the absorbent article and, therefore, provide for better bodily fluid acquisition.
The present disclosure is directed, in part, to an absorbent article comprising a first end edge, a second end edge, a first side edge, a second side edge, and a three-piece topsheet forming at least a portion of a wearer-facing surface. The three-piece topsheet comprises a first material positioned proximate to the first side edge and extending at least partially between the first end edge and the second end edge, a second material positioned proximate to the second side edge and extending at least partially between the first end edge and the second end edge, and a third material positioned intermediate the first material and the second material and extending at least partially between the first end edge and the second end edge. The first and second materials comprise the same material. The third material comprises a nonwoven acquisition material. The nonwoven acquisition material has a first surface and a second surface. The nonwoven acquisition material comprises a plurality of fibers, a generally planar first region, and a plurality of discrete integral second regions that comprise deformations forming protrusions extending outwardly from the first surface of the nonwoven acquisition material and openings in the second surface of the nonwoven acquisition material. Protrusions are formed from the fibers. The protrusions extend towards the absorbent core. The protrusions comprise a base proximate to the first surface of the nonwoven acquisition material, an opposed distal end extending outward in the Z-direction from the base, side walls between the base and the distal end of the protrusion, and a cap comprising at least a portion of the side walls and the distal end of the protrusions. The side walls have interior surfaces. Multiple fibers extend from the base of the protrusions to the distal end of the protrusions, and contribute to form a portion of the sides, ends, and caps of a protrusion. The fibers at least substantially surround the sides and ends of the protrusions. The interior surfaces of the side walls define a base opening at the base of the protrusion. The cap has a portion with a maximum interior width. The base opening has a width. The maximum interior width of the cap of the protrusions is greater than the width of the base opening.
The above-mentioned and other features and advantages of the present disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following description of non-limiting embodiments of the disclosure taken in conjunction with the accompanying drawings, wherein:
Various non-limiting forms of the present disclosure will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the multi-component topsheets having three-dimensional materials disclosed herein. One or more examples of these non-limiting forms are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the multi-component topsheets having three-dimensional materials described herein and illustrated in the accompanying drawings are non-limiting example forms and that the scope of the various non-limiting forms of the present disclosure are defined solely by the claims. The features illustrated or described in connection with one non-limiting form may be combined with the features of other non-limiting forms. Such modifications and variations are intended to be included within the scope of the present disclosure.
The term “absorbent article” includes disposable articles such as sanitary napkins, panty liners, tampons, interlabial devices, wound dressings, pants, diapers, adult incontinence articles, wipes, and the like. At least some of such absorbent articles are intended for the absorption of body liquids, such as menses or blood, vaginal discharges, urine, and feces. Wipes may be used to absorb body liquids, or may be used for other purposes, such as for cleaning surfaces. Various absorbent articles described above will typically comprise a liquid pervious topsheet, a liquid impervious backsheet joined to the topsheet, and an absorbent core between the topsheet and backsheet. The nonwoven material described herein can comprise at least part of other articles such as scouring pads, wet or dry-mop pads (such as SWIFFER® pads), and the like.
The term “absorbent core”, as used herein, refers to the component of the absorbent article that is primarily responsible for storing liquids. As such, the absorbent core typically does not include the topsheet or backsheet of the absorbent article.
The term “aperture”, as used herein, refers to a predetermined and intentional hole that extends completely through a web or structure (that is, a through hole). The apertures can either be punched cleanly through the web so that the material surrounding the aperture lies in the same plane as the web prior to the formation of the aperture (a “two dimensional” aperture), or the holes can be formed such that at least some of the material surrounding the opening is pushed out of the plane of the web. In the latter case, the apertures may resemble a depression with an aperture therein, and may be referred to herein as a “three dimensional” aperture, a subset of apertures. The term “aperture” does not refer to unintentional variances in the nonwoven material or unintentional tears formed during manufacturing, such as the unintentional tears illustrated in
Characteristic dimensions of the apertures (that is: length, width, aspect ratio, area) are all measured without strain applied at the time of making the measurement using a microscope at 60× magnification. The aspect ratio is defined as ratio between the largest length and the largest width.
The term “component” of an absorbent article, as used herein, refers to an individual constituent of an absorbent article, such as a topsheet, acquisition layer, liquid handling layer, absorbent core or layers of absorbent cores, backsheets, and barriers such as barrier layers and barrier cuffs.
The term “cross-machine direction” or “CD” means the path that is perpendicular to the machine direction in the plane of the web.
The term “deformable material”, as used herein, is a material which is capable of changing its shape or density in response to applied stresses or strains.
The term “discrete”, as used herein, means distinct or unconnected. When the term “discrete” is used relative to forming elements on a forming member, it is meant that the distal (or radially outwardmost) ends of the forming elements are distinct or unconnected in all directions, including in the machine and cross-machine directions (even though bases of the forming elements may be formed into the same surface of a roll, for example).
The term “disposable” is used herein to describe absorbent articles and other products which are not intended to be laundered or otherwise restored or reused as an absorbent article or product (i.e., they are intended to be discarded after use and, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner).
The term “forming elements”, as used herein, refers to any elements on the surface of a forming member that are capable of deforming a web.
The term “integral”, as used herein as in “integral extension” when used to describe the protrusions, refers to fibers of the protrusions having originated from the fibers of the precursor web(s). Thus, as used herein, “integral” is to be distinguished from fibers introduced to or added to a separate precursor web for the purpose of making the protrusions.
The term “joined to” encompasses configurations in which an element is directly secured to another element by affixing the element directly to the other element; configurations in which the element is indirectly secured to the other element by affixing the element to intermediate member(s) which in turn are affixed to the other element; and configurations in which one element is integral with another element, i.e., one element is essentially part of the other element. The term “joined to” encompasses configurations in which an element is secured to another element at selected locations, as well as configurations in which an element is completely secured to another element across the entire surface of one of the elements. The term “joined to” includes any known manner in which elements can be secured including, but not limited to mechanical entanglement.
The term “machine direction” or “MD” means the path that material, such as a web, follows through a manufacturing process.
The term “macroscopic”, as used herein, refers to structural features or elements that are readily visible and distinctly discernable to a human having 20/20 vision when the perpendicular distance between the viewer's eye and the web is about 12 inches (30 cm). Conversely, the term “microscopic” refers to such features that are not readily visible and distinctly discernable under such conditions.
The term “mechanically deforming”, as used herein, refers to processes in which a mechanical force is exerted upon a material in order to permanently deform the material.
The term “permanently deformed”, as used herein, refers to the state of a deformable material whose shape or density has been permanently altered in response to applied stresses or strains.
The terms “SELF” and “SELF'ing”, refer to Procter & Gamble technology in which SELF stands for Structural Elastic Like Film. While the process was originally developed for deforming polymer film to have beneficial structural characteristics, it has been found that the SELF'ing process can be used to produce beneficial structures in other materials. Processes, apparatuses, and patterns produced via SELF are illustrated and described in U.S. Pat. Nos. 5,518,801; 5,691,035; 5,723,087; 5,891,544; 5,916,663; 6,027,483; and 7,527,615 B2.
The term “tuft”, as used herein, refers to a particular type of feature that may be formed from fibers in a nonwoven web. Tufts may have a tunnel-like configuration which may be open at both of their ends.
The term “web” is used herein to refer to a material whose primary dimension is X-Y, i.e., along its length (or longitudinal direction) and width (or transverse direction). It should be understood that the term “web” is not necessarily limited to single layers or sheets of material. Thus the web can comprise laminates or combinations of several sheets of the requisite type of materials.
The term “Z-dimension” refers to the dimension orthogonal to the length and width of the web or article. The Z-dimension usually corresponds to the thickness of the web or material. As used herein, the term “X-Y dimension” refers to the plane orthogonal to the thickness of the web or material. The X-Y dimension usually corresponds to the length and width, respectively, of the web or material.
The present disclosure is directed to nonwoven materials having discrete three-dimensional deformations, which deformations provide protrusions on one side of the material, and openings on the other side of the nonwoven materials. Methods of making the nonwoven materials are also disclosed. The nonwoven materials can be used in absorbent articles and other articles.
As used herein, the term “nonwoven” refers to a web or material having a structure of individual fibers or threads which are interlaid, but not in a repeating pattern as in a woven or knitted fabric, which latter types of fabrics do not typically have randomly oriented or substantially randomly-oriented fibers. Nonwoven webs will have a machine direction (MD) and a cross machine direction (CD) as is commonly known in the art of web manufacture. By “substantially randomly oriented” is meant that, due to processing conditions of the precursor web, there may be a higher amount of fibers oriented in the MD than the CD, or vice versa. For example, in spunbonding and meltblowing processes continuous strands of fibers are deposited on a support moving in the MD. Despite attempts to make the orientation of the fibers of the spunbond or meltblown nonwoven web truly “random,” usually a slightly higher percentage of fibers are oriented in the MD as opposed to the CD.
Nonwoven webs and materials are often incorporated into products, such as absorbent articles, at high manufacturing line speeds. Such manufacturing processes can apply compressive and shear forces on the nonwoven webs that may damage certain types of three-dimensional features that have been purposefully formed in such webs. In addition, in the event that the nonwoven material is incorporated into a product (such as a disposable diaper) that is made or packaged under compression, it becomes difficult to preserve the three-dimensional character of some types of prior three-dimensional features after the material is subjected to such compressive forces.
For instance,
While such a nonwoven material 10 provides well-defined tufts 12, the opening 20 at the base of the tuft structure can be relatively narrow and difficult to see with the naked eye. In addition, as shown in
Prior art nonwoven materials with certain other types of three dimensional deformations, such as conical structures, can also be subject to collapse when compressed. As shown in
The nonwoven materials of at least some embodiments of the present disclosure described herein are intended to better preserve the structure of discrete three-dimensional features in the nonwoven materials after compression.
The protrusions 32 may, in some cases, be formed from looped fibers (which may be continuous) 38 that are pushed outward so that they extend out of the plane of the nonwoven web in the Z-direction. The protrusions 32 will typically comprise more than one looped fiber. In some cases, the protrusions 32 may be formed from looped fibers and at least some broken fibers. In addition, in the case of some types of nonwoven materials (such as carded materials, which are comprised of shorter fibers), the protrusions 32 may be formed from loops comprising multiple discontinuous fibers. Multiple discontinuous fibers in the form of a loop are shown as layer 30A in
In some cases, if male/female forming elements are used to form the protrusions 32, and the female forming elements substantially surround the male forming elements, the fibers in at least part of the protrusions 32 may remain substantially randomly oriented (rather than aligned), similar to their orientation in the precursor web(s). For example, in some cases, the fibers may remain substantially randomly oriented in the cap of the protrusions, but be more aligned in the side walls such that the fibers extend in the Z-direction from the base of the protrusions to the cap. In addition, if the precursor web comprises a multi-layer nonwoven material, the alignment of fibers can vary between layers, and can also vary between different portions of a given protrusion 32 within the same layer.
The nonwoven material 30 may comprise a generally planar first region 40 and the three-dimensional deformations may comprise a plurality of discrete integral second regions 42. The term “generally planar” is not meant to imply any particular flatness, smoothness, or dimensionality. Thus, the first region 40 can include other features that provide the first region 40 with a topography. Such other features can include, but are not limited to small projections, raised network regions around the base openings 44, and other types of features. Thus, the first region 40 is generally planar when considered relative to the second regions 42. The first region 40 can have any suitable plan view configuration. In some cases, the first region 40 is in the form of a continuous inter-connected network which comprises portions that surround each of the deformations.
The term “deformation”, as used herein, includes both the protrusions 32 formed on one side of the nonwoven material and the base openings 44 formed in the opposing side of the material. The base openings 44 are most often not in the form of an aperture or a through-hole. The base openings 44 may instead appear as depressions. The base openings 44 can be analogized to the opening of a bag. A bag has an opening that typically does not pass completely through the bag. In the case of the present nonwoven materials 30, as shown in
As shown in
As shown in
As shown in
The protrusions 32 may be of any suitable shape. Since the protrusions 32 are three-dimensional, describing their shape depends on the angle from which they are viewed. When viewed from above (that is, perpendicular to the plane of the web, or plan view) such as in
As shown in
When the protrusions 32 have a length L that is greater than their width W, the length of the protrusions may be oriented in any suitable direction relative to the nonwoven material 30. For example, the length of the protrusions 32 (that is, the longitudinal axis, LA, of the protrusions) may be oriented in the machine direction, the cross-machine direction, or any desired orientation between the machine direction and the cross-machine direction. The protrusions 32 also have a transverse axis TA generally orthogonal to the longitudinal axis LA in the MD-CD plane. In the embodiment shown in
The protrusions 32 may have any suitable shape when viewed from the side. Suitable shapes include those in which there is a distal portion or “cap” with an enlarged dimension and a narrower portion at the base when viewed from at least one side. The term “cap” is analogous to the cap portion of a mushroom. (The cap does not need to resemble that of any particular type of mushroom. In addition, the protrusions 32 may, but need not, have a mushroom-like stem portion.) In some cases, the protrusions 32 may be referred to as having a bulbous shape when viewed from the end 60, such as in
The protrusions 32 may comprise fibers 38 that at least substantially surround the sides of the protrusions. This means that there are multiple fibers that extend (e.g., in the Z-direction) from the base 50 of the protrusions 32 to the distal end 54 of the protrusions, and contribute to form a portion of the sides 56 and cap 52 of a protrusion. In some cases, the fibers may be substantially aligned with each other in the Z-direction in the sides 56 of the protrusions 32. The phrase “substantially surround”, thus, does not require that each individual fiber be wrapped in the X-Y plane substantially or completely around the sides of the protrusions. If the fibers 38 are located completely around the sides of the protrusions, this would mean that the fibers are located 360° around the protrusions. The protrusions 32 may be free of large openings at their ends 60, such as those openings 18 at the leading end and trailing end of the tufts shown in
The protrusions 32 may have certain additional characteristics. As shown in
The side walls 56 of the protrusions 32 can have any suitable configuration. The configuration of the side walls 56, when viewed from the end of the protrusion such as in
In some embodiments, the distal end 54 of the protrusions 32 may be comprised of original basis weight, non-thinned, and non-broken fibers. If the base opening 44 faces upward, the distal end 54 will be at the bottom of the depression that is formed by the protrusion. The distal end 54 will be free from apertures formed completely through the distal end. Thus, the nonwoven materials may be nonapertured. The term “apertures”, as used herein, refers to holes formed in the nonwovens after the formation of the nonwovens, and does not include the pores typically present in nonwovens. The term “apertures” also does not refer to irregular breaks (or interruptions) in the nonwoven material(s) such as shown in
The protrusions 32 may be of any suitable size. The size of the protrusions 32 can be described in terms of protrusion length, width, caliper, height, depth, cap size, and opening size. (Unless otherwise stated, the length L and width W of the protrusions are the exterior length and width of the cap 52 of the protrusions.) The dimensions of the protrusions and openings can be measured before and after compression (under either a pressure of 7 kPa or 35 KPa, whichever is specified) in accordance with the Accelerated Compression Method described in the Test Methods section. The protrusions have a caliper that is measured between the same points as the height H, but under a 2 KPa load, in accordance with the Accelerated Compression Method. All dimensions of the protrusions and openings other than caliper (that is, length, width, height, depth, cap size, and opening size) are measured without pressure applied at the time of making the measurement using a microscope at 20× magnification.
In some embodiments, the length of the cap 52 may be in a range from about 1.5 mm to about 10 mm. In some embodiments, the width of the cap (measured where the width is the greatest) may be in a range from about 1.5 mm to about 5 mm. The cap portion of the protrusions may have a plan view surface area of at least about 3 mm2. In some embodiments, the protrusions may have a pre-compression height H that is in a range from about 1 mm to about 10 mm, alternatively from about 1 mm to about 6 mm. In some embodiments, the protrusions may have a post-compression height H that is in a range from about 0.5 mm to about 6 mm, alternatively from about 0.5 mm to about 1.5 mm. In some embodiments, the protrusions may have a depth D, in an uncompressed state that is in a range from about 0.5 mm to about 9 mm, alternatively from about 0.5 mm to about 5 mm. In some embodiments, the protrusions may have a depth D, after compression that is in a range from about 0.25 mm to about 5 mm, alternatively from about 0.25 mm to about 1 mm.
The nonwoven material 30 can comprise a composite of two or more nonwoven materials that are joined together. In such a case, the fibers and properties of the first layer will be designated accordingly (e.g., the first layer is comprised of a first plurality of fibers), and the fibers and properties of the second and subsequent layers will be designated accordingly (e.g., the second layer is comprised of a second plurality of fibers). In a two or more layer structure, there are a number of possible configurations the layers may take following the formation of the deformations therein. These will often depend on the extensibility of the nonwoven materials used for the layers. It is desirable that at least one of the layers have deformations which form protrusions 32 as described herein in which, along at least one cross-section, the width of the cap 52 of the protrusions is greater than the width of the base opening 44 of the deformations. For example, in a two layer structure where one of the layers will serve as the topsheet of an absorbent article and the other layer will serve as an underlying layer (such as an acquisition layer), the layer that has protrusions therein may comprise the topsheet layer. The layer that most typically has a bulbous shape will be the one which is in contact with the male forming member during the process of deforming the web.
In certain embodiments, such as shown in
As shown in
As shown in
Alternatively, as shown in
For dual layer and other multiple layer structures, the basis weight distribution (or the concentration of fibers) within the deformed material 30, as well as the distribution of any thermal point bonds 46 can be different between the layers. As used herein, the term “fiber concentration” has a similar meaning as basis weight, but fiber concentration refers to the number of fibers/given area, rather than g/area as in basis weight. In the case of bond sites 46, the fibers may be melted which may increase the density of the material in the bond sites 46, but the number of fibers will typically be the same as before melting.
Some such dual and multiple layer nonwoven materials may be described in terms of such differences between layers, without requiring one or more of the other features described herein (such as characteristics of the cap portion; controlled collapse under compression; and varying width of the protrusions). Of course such dual and multiple layer nonwoven materials may have any of these other features.
In such dual and multiple layer nonwoven materials each of the layers comprises a plurality of fibers, and in certain embodiments, the protrusions 32 will be formed from fibers in each of the layers. For example, one of the layers, a first layer, may form the first surface 34 of the nonwoven material 30, and one of the layers, a second layer, may form the second surface 36 of the nonwoven material 30. A portion of the fibers in the first layer form part of: the first region 40, the side walls 56 of the protrusions, and the distal ends 54 of the protrusions 32. A portion of the fibers in the second layer form part of: the first region 40, the side walls 56 of the protrusions, and the distal ends 54 of the protrusions 32.
As shown in
Forming deformations in the nonwoven material may also affect the bonds 46 (thermal point bonds) within the layer (or layers). In some embodiments, the bonds 46 within the distal end 54 of the protrusions 32 may remain intact (not be disrupted) by the deformation process that formed the protrusions 32. In the side walls 56 of the protrusions 32, however, the bonds 46 originally present in the precursor web may be disrupted. When it is said that the bonds 46 may be disrupted, this can take several forms. The bonds 46 can be broken and leave remnants of a bond. In other cases, such as where the nonwoven precursor material is underbonded, the fibers can disentangle from a lightly formed bond site (similar to untying a bow), and the bond site will essentially disappear. In some cases, after the deformation process, the side walls 56 of at least some of the protrusions 32 may be substantially free (or completely free) of thermal point bonds.
Numerous embodiments of dual layer and other multiple layer structures are possible. For example, a nonwoven layer 30B such as that shown in
In other embodiments, the acquisition layer 30A described in the preceding paragraph may have thermal point bonds 46 within first region 40 of nonwoven layer 30B and the distal end 54 of the protrusions 32 that remain intact. In the side walls 56 of the protrusions 32, however, the bonds 46 originally present in the precursor web comprising the acquisition layer 30A are disrupted such that the side walls 56 of the acquisition layer 30A are substantially free of thermal point bonds. In other cases, the thermal point bonds in the acquisition layer 30A at the top of the protrusions 32 may also be disrupted so that the distal end 54 of at least some of the protrusions are substantially or completely free of thermal point bonds.
In other embodiments, a dual layer or multiple layer structure may comprise a topsheet and an acquisition layer that is oriented with its base openings facing upward in which the concentration of fibers at the distal end 54 of each layer (relative to other portions of the layer) differs between layers. For example, in one embodiment, in the layer that forms the topsheet (second layer), the concentration of fibers in the first region and the distal ends of the protrusions are each greater than the concentration of fibers in the side walls of the protrusions. In the layer that forms the acquisition layer (first layer), the concentration of fibers in the first region of the acquisition layer may be greater than the concentration of fibers in the distal ends of the protrusions. In a variation of this embodiment, the concentration of fibers in the first region of the first layer (acquisition layer) is greater than the concentration of fibers in the side walls of the protrusions in the first layer, and the concentration of fibers in the side walls of the protrusions in the first layer is greater than the concentration of fibers forming the distal ends of the protrusions in the first layer. In some embodiments in which the first layer comprises a spunbond nonwoven material (in which the precursor material had thermal point bonds distributed substantially evenly throughout), a portion of the fibers that form the first region in the first layer comprise thermal point bonds, and the portion of the fibers in the first layer forming the side walls and distal ends of at least some of the protrusions may be substantially free of thermal point bonds. In these embodiments, in at least some of the protrusions, at least some of the fibers in the first layer may form a nest or circle around (that is, encircle) the perimeter of the protrusion at the transition between the wide wall and the base of the protrusion as shown in
The base openings 44 can be of any suitable shape and size. The shape of the base opening 44 will typically be similar to, or the same as, the plan view shape of the corresponding protrusions 32. The base opening 44 may have a width that is greater than about any of the following dimensions before (and after compression): 0.5 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or any 0.1 mm increment above 1 mm. The width of the base opening 44 may be in a range that is from any of the foregoing amounts up to about 4 mm, or more. The base openings 44 may have a length that ranges from about 1.5 mm or less to about 10 mm, or more. The base openings 44 may have an aspect ratio that ranges from about 1:1 to 20:1, alternatively from about 1:1 to 10:1. Measurements of the dimensions of the base opening can be made on a photomicrograph. When the size of the width of the base opening 44 is specified herein, it will be appreciated that if the openings are not of uniform width in a particular direction, the width, WO, is measured at the widest portion as shown in
The deformations may compress under load. In some cases, it may be desirable that the load is low enough so that, if the nonwoven is worn against a wearer's body, with the deformations in contact with the wearer's body, the deformations will be soft and will not imprint the skin. This applies in cases where either the protrusions 32 or the base openings 44 are oriented so that they are in contact with the wearer's body. For example, it may be desirable for the deformations to compress under pressures of 2 kPa or less. In other cases, it will not matter if the deformations imprint the wearer's skin. It may be desirable for at least one of the protrusions 32 in the nonwoven material 30 to collapse or buckle in the controlled manner described below under the 7 kPa load when tested in accordance with the Accelerated Compression Method in the Test Methods section below. Alternatively, at least some, or in other cases, a majority of the protrusions 32 may collapse in the controlled manner described herein. Alternatively, substantially all of the protrusions 32 may collapse in the controlled manner described herein. The ability of the protrusions 32 to collapse may also be measured under a load of 35 kPa. The 7 kPa and 35 kPa loads simulate manufacturing and compression packaging conditions. Wear conditions can range from no or limited pressure (if the wearer is not sitting on the absorbent article) up to 2 kPa, 7 kPa, or more.
The protrusions 32 may collapse in a controlled manner after compression to maintain the wide opening 44 at the base.
The deformations can be disposed in any suitable density across the surface of the nonwoven material 30. The deformations may, for example, be present in a density of: from about 5 to about 100 deformations; alternatively from about 10 to about 50 deformations; alternatively from about 20 to about 40 deformations, in an area of 10 cm2.
The deformations can be disposed in any suitable arrangement across the plane of the nonwoven material. Suitable arrangements include, but are not limited to: staggered arrangements, and zones.
The nonwoven webs 30 described herein can comprise any suitable component or components of an absorbent article. For example, the nonwoven webs can comprise the topsheet of an absorbent article, or as shown in
A two or more layer nonwoven structure may provide fluid handling benefits. If the layers are integrated together, and the protrusions 32 are oriented toward the absorbent core, they may also provide a dryness benefit. It may be desirable, on the other hand, for the protrusions 32 to point outward, away from the absorbent core in a pad for a wet or dry mop to provide a cleaning benefit. In some embodiments, when the nonwoven web 30 is incorporated into an absorbent article, the underlying layers can be either substantially, or completely free, of tow fibers. Suitable underlying layers that are free of tow fibers may, for example, comprise a layer or patch of cross-linked cellulose fibers. In some cases, it may be desirable that the nonwoven material 30 is not entangled with (that is, is free from entanglement with) another web.
The layers of the nonwoven structure (e.g., a topsheet and/or acquisition layer) may be colored. Color may be imparted to the webs in any suitable manner including, but not limited to by color pigmentation. The term “color pigmentation” encompasses any pigments suitable for imparting a non-white color to a web. This term therefore does not include “white” pigments such as TiO2 which are typically added to the layers of conventional absorbent articles to impart them with a white appearance. Pigments are usually dispersed in vehicles or substrates for application, as for instance in inks, paints, plastics or other polymeric materials. The pigments may for example be introduced in a polypropylene masterbatch. A masterbatch comprises a high concentration of pigment and/or additives which are dispersed in a carrier medium which can then be used to pigment or modify the virgin polymer material into a pigmented bicomponent nonwoven. An example of suitable colored masterbatch material that can be introduced is Pantone color 270 Sanylen violet PP 42000634 ex Clariant, which is a PP resin with a high concentration of violet pigment. Typically, the amount of pigments introduced by weight of the webs may be of from 0.3%-2.5%. Alternatively, color may be imparted to the webs by way of impregnation of a colorant into the substrate. Colorants such as dyes, pigments, or combinations may be impregnated in the formation of substrates such as polymers, resins, or nonwovens. For example, the colorant may be added to molten batch of polymer during fiber or filament formation.
Precursor Materials.
The nonwoven materials of the present disclosure can be made of any suitable nonwoven materials (“precursor materials”). The nonwoven webs can be made from a single layer, or multiple layers (e.g., two or more layers). If multiple layers are used, they can be comprised of the same type of nonwoven material, or different types of nonwoven materials. In some cases, the precursor materials may be free of any film layers.
The fibers of the nonwoven precursor material(s) can be made of any suitable materials including, but not limited to natural materials, synthetic materials, and combinations thereof. Suitable natural materials include, but are not limited to cellulose, cotton linters, bagasse, wool fibers, silk fibers, etc. Cellulose fibers can be provided in any suitable form, including but not limited to individual fibers, fluff pulp, drylap, liner board, etc. Suitable synthetic materials include, but are not limited to nylon, rayon and polymeric materials. Suitable polymeric materials include, but are not limited to: polyethylene (PE), polyester, polyethylene terephthalate (PET), polypropylene (PP), and co-polyester. In some embodiments, however, the nonwoven precursor materials can be either substantially, or completely free, of one or more of these materials. For example, in some embodiments, the precursor materials may be substantially free of cellulose, and/or exclude paper materials. In some embodiments, one or more precursor materials can comprise up to 100% thermoplastic fibers. The fibers in some cases may, therefore, be substantially non-absorbent. In some embodiments, the nonwoven precursor materials can be either substantially, or completely free, of tow fibers.
The precursor nonwoven materials can comprise any suitable types of fibers. Suitable types of fibers include, but are not limited to: monocomponent, bicomponent, and/or biconstituent, non-round (e.g., shaped fibers (including but not limited to fibers having a trilobal cross-section) and capillary channel fibers). The fibers can be of any suitable size. The fibers may, for example, have major cross-sectional dimensions (e.g., diameter for round fibers) ranging from 0.1-500 microns. Fiber size can also be expressed in denier, which is a unit of weight per length of fiber. The constituent fibers may, for example, range from about 0.1 denier to about 100 denier. The constituent fibers of the nonwoven precursor web(s) may also be a mixture of different fiber types, differing in such features as chemistry (e.g., PE and PP), components (mono- and bi-), shape (i.e. capillary channel and round) and the like.
The nonwoven precursor webs can be formed from many processes, such as, for example, air laying processes, wetlaid processes, meltblowing processes, spunbonding processes, and carding processes. The fibers in the webs can then be bonded via spunlacing processes, hydroentangling, calendar bonding, through-air bonding and resin bonding. Some of such individual nonwoven webs may have bond sites 46 where the fibers are bonded together.
In the case of spunbond webs, the web may have a thermal point bond 46 pattern that is not highly visible to the naked eye. For example, dense thermal point bond patterns are equally and uniformly spaced are typically not highly visible. After the material is processed through the mating male and female rolls, the thermal point bond pattern is still not highly visible. Alternatively, the web may have a thermal point bond pattern that is highly visible to the naked eye. For example, thermal point bonds that are arranged into a macro-pattern, such as a diamond pattern, are more visible to the naked eye. After the material is processed through the mating male and female rolls, the thermal point bond pattern is still highly visible and can provide a secondary visible texture element to the material.
The basis weight of nonwoven materials is usually expressed in grams per square meter (gsm). The basis weight of a single layer nonwoven material can range from about 8 gsm to about 100 gsm, depending on the ultimate use of the material 30. For example, the topsheet of a topsheet/acquisition layer laminate or composite may have a basis weight from about 8 to about 40 gsm, or from about 8 to about 30 gsm, or from about 8 to about 20 gsm. The acquisition layer may have a basis weight from about 10 to about 120 gsm, or from about 10 to about 100 gsm, or from about 10 to about 80 gsm. The basis weight of a multi-layer material is the combined basis weight of the constituent layers and any other added components. The basis weight of multi-layer materials of interest herein can range from about 20 gsm to about 150 gsm, depending on the ultimate use of the material 30. The nonwoven precursor webs may have a density that is between about 0.01 and about 0.4 g/cm3 measured at 0.3 psi (2 kPa).
The precursor nonwoven webs may have certain desired characteristics. The precursor nonwoven web(s) each have a first surface, a second surface, and a thickness. The first and second surfaces of the precursor nonwoven web(s) may be generally planar. It is typically desirable for the precursor nonwoven web materials to have extensibility to enable the fibers to stretch and/or rearrange into the form of the protrusions. If the nonwoven webs are comprised of two or more layers, it may be desirable for all of the layers to be as extensible as possible. Extensibility is desirable in order to maintain at least some non-broken fibers in the sidewalls around the perimeter of the protrusions. It may be desirable for individual precursor webs, or at least one of the nonwovens within a multi-layer structure, to be capable of undergoing an apparent elongation (strain at the breaking force, where the breaking force is equal to the peak force) of greater than or equal to about one of the following amounts: 100% (that is double its unstretched length), 110%, 120%, or 130% up to about 200%. It is also desirable for the precursor nonwoven webs to be capable of undergoing plastic deformation to ensure that the structure of the deformations is “set” in place so that the nonwoven web will not tend to recover or return to its prior configuration.
Materials that are not extensible enough (e.g., inextensible PP) may form broken fibers around much of the perimeter of the deformation, and create more of a “hanging chad” 90 (i.e., the cap 52 of the protrusions 32 may be at least partially broken from and separated from the rest of the protrusion (as shown in
When the fibers of a nonwoven web are not very extensible, it may be desirable for the nonwoven to be underbonded as opposed to optimally bonded. A thermally bonded nonwoven web's tensile properties can be modified by changing the bonding temperature. A web can be optimally or ideally bonded, underbonded, or overbonded. Optimally or ideally bonded webs are characterized by the highest breaking force and apparent elongation with a rapid decay in strength after reaching the breaking force. Under strain, bond sites fail and a small amount of fibers pull out of the bond site. Thus, in an optimally bonded nonwoven, the fibers 38 will stretch and break around the bond sites 46 when the nonwoven web is strained beyond a certain point. Often there is a small reduction in fiber diameter in the area surrounding the thermal point bond sites 46. Underbonded webs have a lower breaking force and apparent elongation when compared to optimally bonded webs, with a slow decay in strength after reaching the breaking force. Under strain, some fibers will pull out from the thermal point bond sites 46. Thus, in an underbonded nonwoven, at least some of the fibers 38 can be separated easily from the bond sites 46 to allow the fibers 38 to pull out of the bond sites and rearrange when the material is strained. Overbonded webs also have a lowered breaking force and elongation when compared to optimally bonded webs, with a rapid decay in strength after reaching the breaking force. The bond sites look like films and result in complete bond site failure under strain.
When the nonwoven web comprises two or more layers, the different layers can have the same properties, or any suitable differences in properties relative to each other. In one embodiment, the nonwoven web 30 can comprise a two layer structure that is used in an absorbent article. For convenience, the precursor webs and the material into which they are formed will generally be referred to herein by the same reference numbers. However, in some cases, for additional clarity the precursor web may be designated as 30′. As described above, one of the layers, a second layer 30B, can serve as the topsheet of the absorbent article, and the first layer 30A can be an underlying layer (or sub-layer) and serve as an acquisition layer. The acquisition layer 30A receives liquids that pass through the topsheet and distributes them to underlying absorbent layers. In such a case, the topsheet 30B may be less hydrophilic than sub-layer(s) 30A, which may lead to better dewatering of the topsheet. In other embodiments, the topsheet can be more hydrophilic than the sub-layer(s). In some cases, the pore size of the acquisition layer may be reduced, for example via using fibers with smaller denier or via increasing the density of the acquisition layer material, to better dewater the pores of the topsheet.
The second nonwoven layer 30B that may serve as the topsheet can have any suitable properties. Properties of interest for the second nonwoven layer, when it serves as a topsheet, in addition to sufficient extensibility and plastic deformation may include uniformity and opacity. As used herein, “uniformity” refers to the macroscopic variability in basis weight of a nonwoven web. As used, herein, “opacity” of nonwoven webs is a measure of the impenetrability of visual light, and is used as visual determination of the relative fiber density on a macroscopic scale. As used herein, “opacity” of the different regions of a single nonwoven deformation is determined by taking a photomicrograph at 20× magnification of the portion of the nonwoven containing the deformation against a black background. Darker areas indicate relatively lower opacity (as well as lower basis weight and lower density) than white areas.
Several examples of nonwoven materials suitable for use as the second nonwoven layer 30B include, but are not limited to: spunbonded nonwovens; carded nonwovens; and other nonwovens with high extensibility (apparent elongation in the ranges set forth above) and sufficient plastic deformation to ensure the structure is set and does not have significant recovery. One suitable nonwoven material as a topsheet for a topsheet/acquisition layer composite structure may be an extensible spunbonded nonwoven comprising polypropylene and polyethylene. The fibers can comprise a blend of polypropylene and polyethylene, or they can be bi-component fibers, such as a sheath-core fiber with polyethylene on the sheath and polypropylene in the core of the fiber. Another suitable material is a bi-component fiber spunbonded nonwoven comprising fibers with a polyethylene sheath and a polyethylene/polypropylene blend core.
The first nonwoven layer 30A that may, for example, serve as the acquisition layer can have any suitable properties. Properties of interest for the first nonwoven layer, in addition to sufficient extensibility and plastic deformation may include uniformity and opacity. If the first nonwoven layer 30A serves as an acquisition layer, its fluid handling properties must also be appropriate for this purpose. Such properties may include: permeability, porosity, capillary pressure, caliper, as well as mechanical properties such as sufficient resistance to compression and resiliency to maintain void volume. Suitable nonwoven materials for the first nonwoven layer when it serves as an acquisition layer include, but are not limited to: spunbonded nonwovens; through-air bonded (“TAB”) carded nonwoven materials; spunlace nonwovens; hydroentangled nonwovens; and, resin bonded carded nonwoven materials. Of course, the composite structure may be inverted and incorporated into an article in which the first layer 30A serves as the topsheet and the second layer 30B serves as an acquisition layer. In such cases, the properties and exemplary methods of the first and second layers described herein may be interchanged.
The layers of a two or more layered nonwoven web structure can be combined together in any suitable manner. In some cases, the layers can be unbonded to each other and held together autogenously (that is, by virtue of the formation of deformations therein). For example, both precursor webs 30A and 30B contribute fibers to deformations in a “nested” relationship that joins the two precursor webs together, forming a multi-layer web without the use or need for adhesives or thermal bonding between the layers. In other embodiments, the layers can be joined together by other mechanisms. If desired an adhesive between the layers, ultrasonic bonding, chemical bonding, resin or powder bonding, thermal bonding, or bonding at discrete sites using a combination of heat and pressure can be selectively utilized to bond certain regions or all of the precursor webs. In addition, the multiple layers may be bonded during processing, for example, by carding one layer of nonwoven onto a spunbond nonwoven and thermal point bonding the combined layers. In some cases, certain types of bonding between layers may be excluded. For example, the layers of the present structure may be non-hydroentangled together.
If adhesives are used, they can be applied in any suitable manner or pattern including, but not limited to: slots, spirals, spray, and curtain coating. Adhesives can be applied in any suitable amount or basis weight including, but not limited to between about 0.5 and about 30 gsm, alternatively between about 2 and about 5 gsm. Examples of adhesives could include hot melt adhesives, such as polyolefins and styrene block copolymers.
A certain level of adhesive may reduce the level of fuzz on the surface of the nonwoven material even though there may be a high percentage of broken fibers as a result of the deformation process. Glued dual-layer laminates produced as described herein are evaluated for fuzz. The method utilizes a Martindale Abrasion Tester, based upon ASTM D4966-98. After abrading the samples, they are graded on a scale of 1-10 based on the degree of fiber pilling (1=no fiber pills; 10=large quantity and size of fiber pills). The protrusions are oriented away from the abrader so the land area in between the depressions is the primary surface abraded. Even though the samples may have a significant amount of fiber breakage (greater than 25%, sometimes greater than 50%) in the side walls of the protrusions/depressions, the fuzz value may be low (around 2) for several different material combinations, as long as the layers do not delaminate during abrasion. Delamination is best prevented by glue basis weight, for example a glue basis weight greater than 3 gsm, and glue coverage.
When the precursor nonwoven web comprises two or more layers, it may be desirable for at least one of the layers to be continuous, such as in the form of a web that is unwound from a roll. In some embodiments, each of the layers can be continuous. In alternative embodiments, such as shown in
The nonwoven materials are made by a method comprising the steps of: a) providing at least one precursor nonwoven web; b) providing an apparatus comprising a pair of forming members comprising a first forming member (a “male” forming member) and a second forming member (a “female” forming member); and c) placing the precursor nonwoven web(s) between the forming members and mechanically deforming the precursor nonwoven web(s) with the forming members. The forming members have a machine direction (MD) orientation and a cross-machine direction (CD) orientation.
The first and second forming members can be plates, rolls, belts, or any other suitable types of forming members. In some embodiments, it may be desirable to modify the apparatus for incrementally stretching a web described in U.S. Pat. No. 8,021,591, Curro, et al. entitled “Method and Apparatus for Incrementally Stretching a Web” by providing the activation members described therein with the forming elements of the type described herein. In the embodiment of the apparatus 100 shown in
First Forming Member.
The first forming member (such as “male roll”) 102 has a surface comprising a plurality of first forming elements which comprise discrete, spaced apart male forming elements 112. The male forming elements are spaced apart in the machine direction and in the cross-machine direction. The term “discrete” does not include continuous or non-discrete forming elements such as the ridges and grooves on corrugated rolls (or “ring rolls”) which have ridges that may be spaced apart in one, but not both, of the machine direction and in the cross-machine direction.
As shown in
The base 116 and the top 118 of the male elements 112 may have any suitable plan view configuration, including but not limited to: a rounded diamond configuration as shown in
The side walls 120 of the male elements 112 may have any suitable configuration. The male elements 112 may have vertical side walls 120, or tapered side walls 120. By vertical side walls, it is meant that the side walls 120 have zero degree side wall angles relative to the perpendicular from the base 116 of the side wall. In other embodiments, as shown in
Numerous other embodiments of the male forming elements 112 are possible. In other embodiments, the top 118 of the male elements 112 can be of different shapes from those shown in the drawings. In other embodiments, the male forming elements 112 can be disposed in other orientations on the first forming member 102 rather than having their length oriented in the machine direction (including CD-orientations, and orientations between the MD and CD). The male forming elements 112 on the first forming member 102 may, but need not, all have the same configuration or properties. In certain embodiments, the first forming member 102 can comprise some male forming elements 112 having one configuration and/or properties, and other male forming elements 112 having one or more different configurations and/or properties.
The method of making the nonwoven materials may be run with the first forming member 102 and male elements 112 under any of the following conditions: at room temperature; with a chilled first forming member 102 and/or male elements 112; or with heated first forming member and/or male elements. In some cases, it may be desired to avoid heating the first forming member 102 and/or male elements 112. It may be desirable to avoid heating the first forming member and/or the male elements altogether. Alternatively, it may be desirable to avoid heating the first forming member and/or the male elements to a temperature at or above that which would cause the fibers of the nonwoven to fuse together. In some cases, it may be desirable to avoid heating the first forming member and/or the male elements to a temperature that is greater than or equal to any of the following temperatures: 130° C., 110° C., 60° C., or greater than 25° C.
Second Forming Member.
As shown in
As a result, the recess 114 on the female roll may completely encompass the discrete male element 112 when the rolls 102 and 104 are intermeshed. The recesses 114 have a depth D1 shown in FIG. 23. In some cases, the depth D1 of the recesses may be greater than the height H1 of the male forming elements 112.
The recesses 114 have a plan view configuration, side walls 128, a top edge or rim 134 around the upper portion of the recess where the side walls 128 meet the surface 124 of the second forming member 104, and a bottom edge 130 around the bottom 132 of the recesses where the side walls 128 meet the bottom 132 of the recesses.
The recesses 114 may have any suitable plan view configuration provided that the recesses can receive the male elements 112 therein. The recesses 114 may have a similar plan view configuration as the male elements 112. In other cases, some or all of the recesses 114 may have a different plan view configuration from the male elements 112.
The side walls 128 of the recesses 114 may be oriented at any suitable angle. In some cases, the side walls 128 of the recesses may be vertical. In other cases, the side walls 128 of the recesses may be oriented at an angle. Typically, this will be an angle that is tapered inwardly from the top 134 of the recess 114 to the bottom 132 of the recess. The angle of the side walls 128 of the recesses can, in some cases, be the same as the angle of the side walls 120 of the male elements 112. In other cases, the angle of the side walls 128 of the recesses can differ from the angle of the side walls 120 of the male elements 112.
The top edge or rim 134 around the upper portion of the recess where the side walls 128 meet the surface 124 of the second forming member 104 may have any suitable configuration. The rim 134 can be in the form of a sharp edge (as shown in
As discussed above, the recesses 114 may be deeper than the height H1 of the male elements 112 so the nonwoven material is not nipped (or squeezed) between the male and female rolls 102 and 104 to the extent possible. However, it is understood that passing the precursor web(s) between two rolls with a relatively small space therebetween will likely apply some shear and compressive forces to the web(s). The present method, however, differs from some embossing processes in which the top of the male elements compress the material to be embossed against the bottom of the female elements, thereby increasing the density of the region in which the material is compressed.
The depth of engagement (DOE) is a measure of the level of intermeshing of the forming members. As shown in
As shown in
Some of the aforementioned male element 112 configurations alone, or in conjunction with the second forming member 104 and/or recess 114 configurations may provide additional advantages. This may be due to by greater lock of the nonwoven material on the male elements 112, which may result in more uniform and controlled strain on the nonwoven precursor material. This may produce more well-defined protrusions 32 and a stronger visual signal for consumers, giving the appearance of softness, absorbency, and/or dryness.
The precursor nonwoven web 30 is placed between the forming members 102 and 104. The precursor nonwoven web can be placed between the forming members with either side of the precursor web (first surface 34 or second surface 36) facing the first forming member, male forming member 102. For convenience of description, the second surface 36 of the precursor nonwoven web will be described herein as being placed in contact with the first forming member 102. (Of course, in other embodiments, the second surface 36 of the precursor nonwoven web can be placed in contact with the second forming member 104.)
The precursor material is mechanically deformed with the forming members 102 and 104 when a force is applied on the nonwoven web with the forming members 102 and 104. The force can be applied in any suitable manner. If the forming members 102 and 104 are in the form of plates, the force will be applied when the plates are brought together. If the forming members 102 and 104 are in the form of counter-rotating rolls (or belts, or any combination of rolls and belts), the force will be applied when the precursor nonwoven web passes through the nip between the counter-rotating elements. The force applied by the forming members impacts the precursor web and mechanically deforms the precursor nonwoven web.
Numerous additional processing parameters are possible. If desired, the precursor nonwoven web may be heated before it is placed between the forming members 102 and 104. If the precursor nonwoven web is a multi-layer structure, any layer or layers of the same can be heated before the layers are combined. Alternatively, the entire multi-layer nonwoven web can be heated before it is placed between the forming members 102 and 104. The precursor nonwoven web, or layer(s) of the same, can be heated in any suitable manner including, but not limited to using conductive heating (such as by bringing the web(s) in contact with heated rolls), or by convective heating (i.e., by passing the same under a hot air knife or through an oven). The heating should be non-targeted, and without the help of any agent. The first forming member 102 and/or second forming member 104 (or any suitable portion thereof) can also be heated. If desired, the web could be additionally, or alternatively, heated after it is mechanically deformed.
If the precursor material is fed between forming members comprising counter-rotating rolls, several processing parameters may be desirable. With regard to the speed at which the precursor web is fed between the counter-rotating rolls, it may be desirable to overfeed the web (create a negative draw) going into the nip 106 between the rolls. The surface speed of the metering roll immediately upstream of the forming members 102 and 104 may be between about 1 and 1.2 times the surface speed of the forming members 102 and 104. It may be desirable for the tension on the precursor web immediately before forming members 102 and 104 to be less than about 5 lbs. force (about 22 N), alternatively less than about 2 lbs. force (about 9 N) for a web width of 0.17 m. With regard to the speed at which the deformed web 30 is removed from between the counter-rotating rolls, it may be desirable to create a positive draw coming out of the nip between the rolls. The surface speed of the metering roll immediately downstream of the forming members 102 and 104 may be between about 1 and 1.2 times the surface speed of the forming members 102 and 104. It may be desirable for the tension on the web immediately after the forming members 102 and 104 to be less than about 5 lbs. force (about 22 N), alternatively less than about 2 lbs. force (about 9 N).
As shown in
The apparatus 100 for deforming the web can comprise multiple nips for deforming portions of the web in the same location such as described in U.S. Patent Publication No. US 2012/0064298 A1, Orr, et al. For example, the apparatus may comprise a central roll and satellite rolls with equal DOE or progressively greater DOE with each successive roll. This can provide benefits such as reducing damage to the web and/or helping to further ensure that the deformations are permanently set in the web thereby preventing the web from recovering toward its undeformed condition.
The apparatus for deforming the web can also comprise belts, or other mechanisms, for holding down the longitudinal edges of the web to prevent the web from being drawn inward in the cross-machine direction.
When deforming multiple webs that are laminated together with an adhesive, it may be desirable to chill the forming members in order to avoid glue sticking to and fouling the forming members. The forming members can be chilled using processes know in the art. One such process could be an industrial chiller that utilizes a coolant, such as propylene glycol. In some cases, it may be desirable to operate the process in a humid environment such that a layer of condensate forms on the forming members.
The apparatus 100 for deforming the web can be at any suitable location in any suitable process. For example, the apparatus can be located in-line with a nonwoven web making process or a nonwoven laminate making process. Alternatively, the apparatus 100 can be located in-line in an absorbent article converting process (such as after the precursor web is unwound and before it is incorporated as part of the absorbent article).
The process forms a nonwoven web 30 comprising a generally planar first region 40 and a plurality of discrete integral second regions 42 that comprise deformations comprising protrusions 32 extending outward from the first surface 34 of the nonwoven web and openings in the second surface 36 of the nonwoven web. (Of course, if the second surface 36 of the precursor nonwoven web is placed in contact with the second forming member 104, the protrusions will extend outward from the second surface of the nonwoven web and the openings will be formed in the first surface of the nonwoven web.) Without wishing to be bound by any particular theory, it is believed that the extensibility of the precursor web (or at least one of the layers of the same) when pushed by the male forming elements 112 into the recesses 114 with depth of engagement DOE being less than the depth D1 of the recesses, stretches a portion of the nonwoven web to form a deformation comprising a protrusion with the enlarged cap and wide base opening described above. (This can be analogized to sticking one's finger into an uninflated balloon to stretch and permanently deform the material of the balloon.)
In cases in which the precursor nonwoven material 30′ comprises more than one layer, and one of the layers is in the form of discrete pieces of nonwoven material, as shown in
In some instances, the ratio of the circumference of the protrusions (loop circumference length) to the length of the second surface opening 64 (see
A plurality of apertures may be formed in the nonwoven material. The nonwoven material may have one or more layers. In one example, the nonwoven material may be a topsheet and acquisition layer of an absorbent article, for example. Apertures may be formed through all of, or through one or more of these layers in the nonwoven material. The apertures may be coincident if formed through one or more of the layers or all of the layers. The apertures may be formed in portions of the generally planar first region and/or in at least some of, or all of, the discrete integral second regions in all of the layers of the nonwoven material or in some of the layers of the nonwoven material. The apertures in the nonwoven material may be formed in a predetermined and intentional pattern. Stated another way, the apertures are not merely unintentional variances in the nonwoven material or unintentional tears formed during manufacturing, such as the unintentional tears illustrated in
Referring to
Referring to
Referring to
In various forms, apertures in the generally planar first regions may be smaller than apertures in the discrete integral second regions. Smaller apertures in the generally planar first regions may be desired for purposes of reduced rewet and softness, since these apertures may be in contact with an absorbent article wearer. Larger apertures in the discrete integral second regions may be desired for fluid handling and do not have rewet and softness issues, since these larger apertures are not in contact with an absorbent article wearer.
For
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Some current two-dimensional apertured topsheets are effective at allowing BM to pass through the topsheet into the layers below. These two-dimensional apertured topsheets, however, provide very little void volume under themselves in that the generally planar topsheets are in a facing relationship with the generally planar layer below (typically at acquisition layer). Thus, BM or other bodily fluid acquisition of these two-dimensional apertured topsheets has its limits and needs to be improved. The three-dimensional nonwoven materials of the present disclosure having apertures provide this improvement in BM or other bodily fluid acquisition, while also providing reduced skin marking and softness, owing to only having small apertures present on generally planar wearer-facing surfaces 922, 1022. The nonwoven materials 930 and 1030 of
The apertures in the nonwoven materials described herein may be formed using any suitable aperturing process, such as pin aperturing, water-jet aperturing, laser aperturing, overbonding and ring rolling aperturing, cutting, and/or hot air aperturing, for example. Referring to
Referring to
First, a precursor material 3102 is supplied as the starting material. The precursor material 3102 may be supplied as discrete webs, e.g. sheets, patches, etc. of material for batch processing. For commercial processing, however, the precursor material 3102 may be supplied as roll stock, and, as such it can be considered as having a finite width and an infinite length. In this context, the length is measured in the machine direction (MD). Likewise, the width is measured in the cross machine direction (CD).
The precursor material 3102 may be one or more nonwoven materials (same or different), one or more films (same or different), a combination of one or more nonwoven materials and one or more films, or any other suitable materials or combinations thereof. In an instance, the precursor material 3102 may comprise a topsheet, an acquisition layer, a tissue layer, a distribution layer, and/or other layer or layers of an absorbent article, for example. The precursor material 3102 may be purchased from a supplier and shipped to where the nonwoven materials of the present disclosure are being formed or the precursor material 3102 formed at the same location as where the nonwoven materials of the present disclosure are being produced.
The precursor material 3102 may be extensible or non-elastic.
The precursor material 3102 may comprise or be made of mono-component, bi-component, multi-constituent blends, or multi-component fibers comprising one or more thermoplastic polymers. In an example, the bicomponent fibers of the present disclosure may be formed of a polypropylene core and a polyethylene sheath, a polypropylene core and polypropylene sheath, or a polyethylene core and a polyethylene sheath. Further details regarding bi-component or multi-component fibers and methods of making the same may be found in U.S. Patent Application Publ. No. 2009/0104831, published on Apr. 23, 2009, U.S. Pat. No. 8,226,625, issued on Jul. 24, 2012, U.S. Pat. No. 8,231,595, issued on Jul. 31, 2012, U.S. Pat. No. 8,388,594, issued on Mar. 5, 2013, and U.S. Pat. No. 8,226,626, issued on Jul. 24, 2012. The various fibers may be sheath/core, side-by-side, islands in the sea, or other known configurations of fibers. The fibers may be round, hollow, or shaped, such as trilobal, ribbon, capillary channel fibers (e.g., 4DG). The fibers may comprise microfibers or nanofibers.
The precursor material 3102 may be unwound from a supply roll 3104 and travel in a direction indicated by the arrow associated therewith as the supply roll 3104 rotates in the direction indicated by the arrow associated therewith. The precursor material 3102 may pass through a nip 3106 of a weakening roller (or overbonding) arrangement 3108 formed by rollers 3110 and 3112, thereby forming a weakened precursor material. The weakened precursor material 3102 may have a pattern of overbonds, or densified and weakened areas, after passing through the nip 3106. At least some of, or all of, these overbonds may be used to form apertures in the precursor material 3102. Therefore, the overbonds may correlate generally to the patterns of apertures created in the precursor material 3102.
Referring to
The patterned calendar roller 3110 may be configured to have a cylindrical surface 3114, and a plurality of protuberances or pattern elements 3116 which extend outwardly from the cylindrical surface 3114. The pattern elements 3116 are illustrated as a simplified example of a pattern of a patterned calendar roller 3110, but other patterned calendar rollers with other patterns may also be used. The protuberances 3116 may be disposed in a predetermined pattern with each of the protuberances 3116 being configured and disposed to precipitate a weakened, melt-stabilized location in the precursor material 3102 to affect a predetermined pattern of weakened, melt-stabilized locations 3202 in the precursor material 3102. The protuberances 3116 may have a one-to-one correspondence to the pattern of melt stabilized locations in the precursor material 3102. As shown in
The protuberances 3116 may extend radially outwardly from the surface 3114 and have distal end surfaces 3117. The anvil roller 3112 may be a smooth surfaced, circular cylinder of steel, rubber or other material. The anvil roller 3112 and the patterned calendar roller 3110 may be switched in position (i.e., anvil on top) and achieve the same result.
From the weakening roller arrangement 3108, the material 3102 may then be passed through a nip 3130 formed by an incremental stretching system 3132 employing opposed pressure applicators having three-dimensional surfaces which at least to a degree may be complementary to one another. The incremental stretching system 3132 is optional. Instead, the material 3102 may be instead sent through the process of
Referring now to
The teeth 3160 on the roller 3134 may intermesh with or engage the grooves 3163 on the roller 3136 while the teeth 3162 on the roller 3136 may intermesh with or engage the grooves 3161 on the roller 3134. The spacing and/or pitch of the teeth 3162 and/or the grooves 3163 may match the pitch and/or spacing of the plurality of weakened, melt stabilized locations 3202 in the precursor material 3102 or may be smaller or larger. As the precursor material 3102 having weakened, melt-stabilized locations 3202 passes through the incremental stretching system 3132 the precursor material 3102 may be subjected to tensioning in the CD causing the material 3102 to be extended (or activated) in the CD, or generally in the CD. Additionally the material 3102 may be tensioned in the MD, or generally in the MD. The CD tensioning force placed on the material 3102 may be adjusted such that it causes the weakened, melt-stabilized locations 3202 to at least partially, or fully, rupture thereby creating a plurality of partially formed, or formed apertures 3204 coincident with the weakened melt-stabilized locations 3202 in the material 3102. However, the bonds of the material 3102 (in the non-overbonded areas) are strong enough such that they do not rupture during tensioning, thereby maintaining the material 3102 in a coherent condition even as the weakened, melt-stabilized locations rupture. However, it may be desirable to have some of the bonds rupture during tensioning.
Referring to
As the material 3102 having the weakened, melt-stabilized locations 3202 passes through the incremental web stretching apparatus 3132, the material 3102 may be subjected to tensioning in the cross machine direction, or substantially in the cross machine direction, thereby causing the nonwoven web 3102 to be extended in the cross machine direction. The tensioning force placed on the material 3102 may be adjusted by varying the pitch, DOE, or teeth size, such that the incremental stretching is sufficient to cause the weakened, melt-stabilized locations 3202 to at least partially, or fully rupture, thereby creating, or at least partially creating, a plurality of apertures 3204 coincident with the weakened, melt-stabilized locations 3202 in the material 3102.
After the material 3102 passes through the incremental web stretching apparatus 3132, the web 3102 may be advanced to and at least partially around a cross machine directional tensioning apparatus 3132′ (see e.g.,
The outer longitudinal portions of the roll may comprise vacuum, a low tack adhesive, a high coefficient of friction material or surface, such as rubber, and/or other mechanisms and/or materials to hold the material 3102 to the outer lateral portions of the roll during movement of the outer longitudinal portion or portions relative to the middle portion of the roll. The vacuum, low tack adhesive, high coefficient of friction material or surface, and/or other mechanisms and/or materials may prevent, or at least inhibit, the held portions of the material 3102 from slipping relative to the longitudinal axis, A, of the roll during stretching of the outer lateral portions of the material in the cross machine direction or generally in the cross machine direction.
Regardless of whether one or both of the outer longitudinal portions 2020 is moved, slid, rotated, fixed, and/or expanded relative to the middle portion 2000, this relative motion or positioning between the outer longitudinal portions 2020 and the middle portion 2000 stretches the materials 3102 in a cross machine direction to further rupture or further define the weakened locations 2020 in the material 3102 and create, or further form, a plurality the apertures 2040 the material 3102. The cross machine directional tensioning force applied by the cross machine directional tensioning apparatus 3132′ may be, for example, 10-25 grams or 15 grams. In an instance, the cross machine directional tensioning apparatus may be similar to, or the same as, the incremental stretching apparatus 3132 to apply the cross machine directional tensioning force. In still other instances, any suitable cross machine directional tensioning apparatus may be used to apply the cross machine directional tensioning force to the material 3102.
If desired, the incremental stretching step or the cross machine directional stretching step described herein may be performed at elevated temperatures. For example, the material 3102 and/or the rolls may be heated. Utilizing heat in the stretching step may serve to soften the material, and may aid in extending the fibers without breaking.
Referring again to
It is important to note that the overbonding step illustrated in
One of ordinary skill in the art will recognize that it may be advantageous to submit the material 3102 to multiple incremental stretching processes depending on various desired characteristics of the finished product. Both the first and any additional incremental stretching may either be done on-line or off-line. Furthermore, one of ordinary skill will recognize that the incremental stretching may be done either over the entire area of the material or only in certain regions of the material depending on the final desired characteristics.
The overbonding and ring rolling process described with respect to
A plurality of different methods may be used to create a three-dimensional nonwoven material with apertures. In an instance, a first layer (e.g., a topsheet, acquisition layer, or other layer) may be overbonded (e.g.,
In other instances, a first layer (e.g., a topsheet, acquisition layer, or other layer may be overbonded (e.g.,
In an instance, a first layer (e.g., a topsheet, acquisition layer, other layer) may be pin apertured or otherwise apertured (either at a supplier or upstream in the process), then may be brought together with one or more second non-apertured layers (e.g., acquisition layer, topsheet, or other layer), and then may be run through the process of
In an instance, a first layer (e.g., a topsheet, acquisition layer, or other layer) may be overbonded (e.g.,
In an instance, a two or more layer laminate (e.g., a topsheet and an acquisition layer, or two other layers) may be overbonded (e.g.,
In an instance, a two or more layer laminate (e.g., a topsheet and an acquisition layer, or two other layers) may be overbonded (e.g.,
In an instance, a two or more layer laminate (e.g., a topsheet and an acquisition layer, or two other layers) may be brought together and overbonded (e.g.,
In an instance, a two or more layer laminate (e.g., a topsheet and an acquisition layer, or two or more other layers) may be brought together and pin apertured or otherwise apertured, and then run through the process of
In an instance, a two or more layer laminate (e.g., a topsheet and an acquisition layer, or two or more other layers) may be separately pre-apertured (using any suitable processes), then brought together, and then run through the process of
In some forms, apertures and the three-dimensional structures may be created in nonwoven materials using a single process. Referring to
By using either male or female forming elements having pins, the pins may form apertures in a substrate passing through the first and second forming members 102 and 104 (see
In other instances, pins may be located intermediate male forming elements on the first forming member 102 to create apertures in portions of the generally planar first region. Pin receiving-cavities may be formed on the second forming member 104 to at least partially receive the pins. In other instances, pins may be located intermediate female forming elements on the second forming roll 104 to create apertures in portions of the generally planar first region. Pin receiving-cavities may be formed on the first forming member 102 to at least partially receive the pins. Either of the first or second forming members 102, 104 may be heated to enable better aperture formation. Using the apparatuses described in this paragraph, apertures may be formed in portions of the generally planar first region. Apertures may also be formed the discrete integral second regions, as described in the preceding paragraph.
In an instance, whether the nonwoven material has apertures or not, in an absorbent article context, portions of a nonwoven acquisition material may form a portion of a wearer-facing surface.
An absorbent article, such as a diaper or a sanitary napkin, may comprise an absorbent core, a backsheet, a first end edge, a second end edge, a first side edge, a second side edge, and a three-piece topsheet forming at least a portion of a wearer-facing surface. The three-piece topsheet may comprise a first material (or topsheet material) positioned proximate to the first side edge and extending at least partially between the first end edge and the second end edge, a second material (or topsheet material) positioned proximate to the second side edge and extending at least partially between the first end edge and the second end edge, and a third material (or acquisition material) positioned intermediate the first material and the second material and extending at least partially between the first end edge and the second end edge. The first and second materials (e.g., 5000) may comprise the same material, which may be one or more generally planar nonwoven materials. In some instances, the first and second materials 500 may be free of the plurality of discrete integral second regions, although they may be embossed, for example. The third material (e.g., 5002) may comprise a nonwoven or other acquisition material. In some instances, none of the first, second, and third materials may extend from the first side edge to the second side edge of the absorbent article. The first and second materials may have the same or substantially the same basis weights while the nonwoven acquisition material may have a different basis weight. The basis weight of the first and second material may be lower than the basis weight of the nonwoven acquisition material. The basis weight of the first and second materials may be in the range of about 5 gsm to about 25 gsm, or about 10 gsm to about 20 gsm, or about 15 gsm, for example, and the basis weight of the third material may be in the range of about 15 gsm to about 100 gsm, for example. The first and second materials may generally be much cheaper materials than the third material, thereby allowing absorbent article manufacturers to use less of the more expensive third material and save significant costs.
Referring to
By providing an acquisition material as part of the wearer-facing surface (i.e., no topsheet material covering most of it, or all of it), BM and other bodily fluids may quickly be absorbed into an absorbent article, as the BM and other bodily fluids may directly contact the acquisition material and not the topsheet material, which typically has a lower permeability that the acquisition material. An additional advantage may be dryness as the acquisition material is typically higher in permeability and has less fluid retention than the topsheet material, thereby providing better dewatering of the acquisition material compared to a topsheet material. The presence of the three-dimensional texture in the acquisition material of the three-piece topsheet may reduce BM, or other bodily fluid spreading (i.e., run-off), improve in acquiring BM, or other bodily fluids, compared to them sticking to the skin, and improve in wiping BM or other bodily fluids off of the skin of a wearer, during wearer movement.
It may be desirable for the acquisition material (e.g., 5002) forming a portion of the wearer-facing surface of an absorbent article to have a low density to provide good permeability and void volume for quickly acquiring bodily fluids. The density of the acquisition material may be less than 0.05 g/cc, but greater than 0.01 g/cc or greater than 0.005 g/cc, or less than 0.03 g/cc, but greater than 0.01 g/cc or greater than 0.005 g/cc, for example. The low density of the acquisition material may lead to improved softness and a good cushiony feel. The low density may be achieved by specific fibers, such as spiral or bicomponent eccentric fibers, such as PE/PET or blending a fraction of thicker fibers. Additionally, the low density may be achieved by re-lofting the nonwoven acquisition material after unwinding it on an absorbent article manufacturing line, by the use of heat tunnels, for example. Softness of the acquisition materials may further be improved by using small denier fibers, for example fibers have a denier less than 4, but greater than 1, or less than 3, but greater than 1. Low density of the acquisition materials in combination with small denier fibers may still deliver sufficient permeability. Additionally, fiber softness may be improved by selecting for the fibers particular polymers, such as polyethylene or soft melt additives, or by coating the fibers with soft polymers. Further, the combination of hydrophobic and hydrophilic fibers may help with facilitating drainage of the bodily fluids into layers below the acquisition materials, wherein hydrophilic and hydrophobic fibers may be blended within the nonwoven acquisition material. In some instances, multilayer configurations of the nonwoven acquisition material may be desirable. Stated another way, the nonwoven acquisition material may be made of different layers where each layer may have different properties. The different properties may comprise fiber composition, fiber shape, hydrophilicity, and/or density. The layers may also have different deniers. The process illustrated in
The apertures may be present in nonwoven materials (e.g., topsheet, or topsheet an acquisition layer laminate) in absorbent articles or other consumer products in patterns and/or zones. For example, a first zone of a nonwoven material may have a first pattern of apertures and a second zone of the nonwoven material may have a second pattern of apertures. The patterns may be the same or different. The first zone may be in the nonwoven material on a first side of a lateral axis of the absorbent article and the second zone may be in the nonwoven material on a second side of the lateral axis, for example. In other instances, the first zone may be a central area of the nonwoven material over at least a portion of a longitudinal axis of the absorbent article and the second zone may be an area at least partially, or fully, surrounding the central area of the nonwoven material. Any other suitable first zones and second zones in the nonwoven material area also within the scope of the present disclosure. More than two zones may also be provided. At least a third zone may have the same pattern of apertures as the first and/or second zones or a different pattern of apertures as the first and/or second zones. The various patterns of apertures may by different in size of apertures, areas of the apertures, shapes of the apertures, placement of the apertures (e.g., in the generally planar first regions or in the discrete integral second regions), and/or angle of the apertures relative to a longitudinal axis of a consumer product (e.g., an absorbent article), for example.
In some instances, apertures may be present in an entire topsheet, or most of the topsheet, and the three-dimensional texture may be present in only a zone. In other instances, apertures may be present in an entire topsheet and acquisition layer, or most of the topsheet and acquisition layer, and the three-dimensional texture may be present in only a zone. In yet other instances, the three-dimensional texture may be present in an entire topsheet, most of the topsheet, an entire topsheet and acquisition layer, or most of the entire topsheet and acquisition layer, and apertures may only be present in a zone of the topsheet or a zone of the topsheet and acquisition layer.
In some instances, the three-dimensional texture may be present in a first zone and apertures may be present in a second zone. The first and second zones may or may not overlap. If the first zone partially overlaps the second zone, only apertures may be present in a non-overlapping area of the second zone, only the three-dimensional texture may be present in a non-overlapping area of the first zone, and both apertures and the three-dimensional texture may be present in the overlapping area of the first and second zones.
In some instances, the three-dimensional texture may be in all zones and the apertures may be in all zones.
In some instances, where the nonwoven material comprises two layers (e.g., a topsheet and an acquisition layer), one or more certain portions of the two layers may not have an adhesive therebetween. By eliminating the adhesive in such one or more certain portions, after an insult of bodily exudates, the layers may at least partially separate and create a void intermediate the layers for receiving at least some of the bodily exudates. Stated another way, such one or more certain portions lacking an adhesive may create an unbonded window that essentially may create a pocket for receiving bodily exudates. Areas around the one or more certain portions may have an adhesive between them such that they remain laminated together even after a bodily exudate insult. In such contexts, the topsheet and acquisition layer may or may not be nested together in the unbonded window. In certain instances, only the topsheet or only the acquisition layer may have the three-dimensional texture.
An absorbent article may comprise the two layer nested nonwoven material described herein having the generally planar first regions and the plurality of discrete integral second regions. The first layer may form a topsheet of the absorbent article. The second layer may form an acquisition layer of the absorbent article. The absorbent article may have a central lateral axis and a central longitudinal axis. The topsheet may have a first width measured parallel to the central lateral axis. The acquisition layer may have a second width measured parallel to the central lateral axis. The first width may be larger than the second width.
An absorbent article may comprise the two layer nested nonwoven material described herein having the generally planar first regions and the plurality of discrete integral second regions. The first layer may form a topsheet of the absorbent article. The second layer may form an acquisition layer of the absorbent article. The absorbent article may have a central lateral axis and a central longitudinal axis. The topsheet may have a first length measured parallel to the central longitudinal axis. The acquisition layer may have a second length measured parallel to the central longitudinal axis. The first length may be larger than the second length.
In a form, an absorbent article may comprises a nested laminate comprising a topsheet and an acquisition layer, a backsheet, and an absorbent core positioned at least partially between the nested laminate and the backsheet. The laminate may comprise a generally planar first region and a plurality of discrete integral second regions that comprise deformations forming three-dimensional protrusions extending toward the core. At least some of the plurality of discrete integral regions may have apertures formed in areas most proximal to the absorbent core. The acquisition layer may be free of apertures.
In a form, an absorbent article may comprise a nested laminate comprising a topsheet and an acquisition layer, a backsheet, and an absorbent core positioned at least partially between the nested laminate and the backsheet. The laminate may comprise a generally planar region and a plurality of discrete three-dimensional structures extending toward the core. At least some of the plurality of discrete three-dimensional structures may have apertures formed in areas proximal to the absorbent core. The acquisition layer may be free of apertures.
A few different topsheet/acquisition layer (TS/AQL) laminates were tested according to the Roll Test procedure below. Each of the TS/AQL laminate samples (labeled as “codes 1-4” below) was tested in such procedure in combination with a 222 gsm cross-linked cellulosic fiber layer glued to an 8 gsm SMS (Spunbond-Meltblown-Spunbond) support layer. Cross-linked cellulosic fiber layers have been used in disposable diapers as part of an acquisition/distribution system, for example, U.S. Pat. Publ. No. 2008/0312622 A1 to Hundorf. The TS/AQL laminate is placed with the AQL side facing the cellulosic fiber layer. The TS/AQL laminate is positioned on the cellulosic fiber layer such that it is centered over both a central lateral axis of the cellulosic fiber layer and a central longitudinal axis of the cellulosic fiber layer. The other side of the cellulosic fiber layer is facing the 8 gsm SMS support layer. The support layer is facing a flat board, such that the entire composite is on the flat board. The laminate is then secured on the board via lateral hooks present on the sides of the board. The TS/AQL laminate was 380 mm long and 180 mm wide, with the AQL being 90 mm wide. The cellulosic fiber layer was 235 mm long and 80 mm wide and had a density of ca. 0.05 g/cm3.
The test fluid is a solution made with 0.5% by weight Carbopol, 5% by weight 1M NaOH solution, 95.4% by weight deionized water.
After the laminate is set up and secured to the board, 5+/−0.01 grams of test fluid are gently and uniformly applied via a syringe onto the topsheet in an area which is 20 mm wide (in a direction parallel to a central lateral axis of the TS/AQL laminate) and 60 mm long (in a direction parallel to a central longitudinal axis of the TS/AQL laminate). The area has 10 mm on each side of the central longitudinal axis of the TS/AQL laminate. The 60 mm length begins at end edge of the cellulosic fiber layer and continues 60 mm toward the other end edge of the cellulosic fiber layer. One minute after the application of the test fluid, a Plexiglas roll, having a diameter of ca. 100 mm, a width of ca. 95 mm, and a weight of 1100 g, is rolled one time over the test fluid without exerting extra pressure to the roll until reaching the opposite end of the TS/AQL laminate material along the central longitudinal axis. The roll is covered with a collagen layer via double sided adhesive tape, wherein the collagen layer is replaced after each replicate of the test.
The TS/AQL laminate and the cellulosic fiber layer are weighed prior to the rolling and after the rolling. The difference between the cellulosic fiber layer's weight after the rolling and the cellulosic fiber layer's weight prior to rolling represents the amount of test fluid that is absorbed into the cellulosic fiber layer (CABS). A higher value of CABS is desired as in fact it means that there is less fluid present over and within the TS/AQL laminate: as the test fluid is a proxy for runny BM of babies, in an in-use situation, this would mean less runny BM closer to the skin of the baby.
Code 5 used the Roll Test procedure as described above, but did not have a TS. So other than the TS/AQL laminate, everything else was the same.
Code 1: Pattern of
Code 2: Pattern of
Code 3: Pattern of
Code 4: Pattern of
Code 5: Pattern of
Amount of test fluid absorbed in the cellulosic fiber layer (CABS)
Where N is the number of replicates.
As can be seen, out of Codes 1-4, Code 4 absorbed the most fluid into the cellulosic fiber layer and Code 4 has apertures at bottom of the plurality of discrete integral second regions and in the generally planar first regions. Thus, apertures in the three-dimensional TS/AQL laminates of the present disclosure perform better in absorbent articles that three-dimensional TS/AQL laminates without apertures.
Further for Code 5, just using an AQL out performed all of Codes 1-4, since no topsheet was present.
Some example aperture sizes were determined in a nonwoven two layer web of the present disclosure in the generally planar first region (as described herein) and in the plurality of discrete integral second regions (as described herein). The apertures in the generally planar first regions were considerable smaller than the apertures in the discrete integral second regions owing to the deformation process (e.g.,
Sample Preparation and MicroCT Scanning
Image Visualization and Analysis
Sample 1 was produced by first overbonding a 25 gsm PE/PP spunbond bicomponent layer, laminating that layer to a layer of 65 gsm carded, through-air bonded PE/PET nonwoven with a spiral glue pattern, and then passing the laminate through a pair of rolls, as illustrated in
Sample 2 was produced in the same way as Sample 1, except the spunbond bicomponent layer was ring rolled (e.g.,
A. Accelerated Compression Method.
B. Tensile Method
The MD and CD tensile properties are measured using World Strategic Partners (WSP) (harmonization of the two nonwovens organizations of INDA (North American based) and EDANA (Europe based)) Tensile Method 110.4 (05) Option B, with a 50 mm sample width, 60 mm gauge length, and 60 mm/min rate of extension. Note that the gauge length, rate of extension and resultant strain rate are from different from that specified within the method.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “90°” is intended to mean “about 90°”.
It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.
All documents cited in the Detailed Description are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present disclosure. To the extent that any meaning or definition of a term in this written document conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this written document shall govern.
While particular embodiments of the present disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
This application claims the benefit, under 35 U.S.C. §119(e), to U.S. Provisional Patent Application No. 62/306,877, filed on Mar. 11, 2016, the entire disclosure of which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62306877 | Mar 2016 | US |
