BACKGROUND

Conventional absorbent articles, including wiping products have been made from woven and knitted fabrics. Such wipers have been used in all different types of industries, such as for industrial applications, food service applications, health and medical applications, and for general consumer use. Conventional rags and washcloths can be reusable if laundered properly. Disposable wipers, however, continue to gain in popularity and are readily displacing many conventional woven or knitted products. Disposable wipers, for instance, can offer many advantages. For example, disposable wipers are generally more sterile, as they are generally free of debris and contaminants, and can also be pre-loaded with a cleaning solvent. Laundered rags and washcloths, for instance, can still contain residual debris from past use and can also pick up debris during the laundering process. In addition, laundering woven or knitted wipers can not only create a great expense, but also requires the use of copious amounts of water and detergents that must be properly disposed of. Further, laundered rags and dishcloths require separate solvents or surfactants to be kept on hand, as they cannot be pre- loaded unlike disposable wipers.

However, disposable wipers are often limited by conflicting interests. For instance, industrial wipers, food service wiping products, household cleaning wipers, medical wiping products, and the like generally need greater amounts of strength and should be capable of absorbing not only water-based solutions but also oily substances. Historically, however, problems have been encountered in producing such wipers that have both good water absorbency properties and good oil absorbency properties. For example, increasing the oil affinity of a wiping product may result in a more hydrophobic sheet that is less water absorbent. Similarly, increasing the water affinity of a wiping product may result in a hydrophilic sheet that has decreased oil absorbency. Additionally, providing a wiping product with good abrasiveness, for example, can limit the softness and overall absorbance of the wiper. Similarly, barrier fabrics, such as those used in masks and performance fabrics suffer from conflicting interests. For instance, treating the barrier fabric to have improved barrier properties can also increase the abrasiveness of the fabric, providing discomfort when the fabric contacted the skin of a user.

Further, altering the characteristics of these articles requires altering the composition used to form the base of the article, such as, by changing the fibers or other components used during formation of the underlying nonwoven web. This can cause further problems, as any change to the base composition can cause tradeoffs as discussed above, cause delays and difficulties during manufacturing, as well as be limited by the underlying properties of the material. Therefore, in one aspect, it would be beneficial to provide a base sheet that has overall improved performance. For instance, in one aspect, it would be beneficial to provide a base sheet that exhibits improved performance in one or more of softness, absorption, abrasion, and barrier properties. Furthermore, it would be beneficial to provide an article formed from a base sheet that exhibits improved properties on opposed sides of the article.

SUMMARY

In one aspect, the present disclosure is generally directed to a base sheet having a microstructured topography. The base sheet includes a nonwoven web having a first surface and an opposed second surface, and extends in a first plane. The base sheet further includes an adhesive, and a plurality of staple fibers that extend in one or more second planes that are not parallel to the first plane, that are affixed to the first surface of the nonwoven web by the adhesive. Furthermore, at least a portion of the staple fibers have a length of about 5000 micrometers or less, a denier of about 5 or less, or a combination thereof.

In a further aspect, the base sheet is a wiping product or an absorbent article. Furthermore, in an aspect, at least a portion of the staple fibers have a length of about 1500 micrometers or less and a denier of about 3 or less, or a length of about 1500 micrometers to about 5000 micrometers, and a denier of about 3 to about 5.

Moreover, in an aspect, the nonwoven web includes elastomeric fibers, three-dimensional fibers, debonded cellulosic fibers, pulp fibers, or mixtures thereof. Additionally or alternatively, the nonwoven web includes polyethylene fibers, polyethylene fibers, pulp fibers, or a combination thereof. In a further aspect, the nonwoven web is a spunbond nonwoven web. Furthermore, in one aspect, the nonwoven web is embossed

In yet another aspect, the plurality of staple fibers include polyethylene fibers, polypropylene fibers, rayon fibers, nylon fibers, or a combination thereof. Furthermore, in an aspect, the adhesive includes an anionic component, the plurality of staple fibers contain a cation, or a combination thereof. In one aspect, the anionic component and adhesive are coated on at least a portion of the nonwoven web. Additionally or alternatively, 50% or more of the nonwoven web is coated with the anionic component and adhesive. In one aspect, the anionic component and adhesive are applied on the nonwoven web in a pattern that includes circles, squares, lines, or a combination thereof. Moreover, in an aspect, the base sheet includes a second plurality of staple fibers adhered to the second surface of the nonwoven web by an adhesive. In an aspect, the second plurality of staple fibers have a different length, denier, or fiber composition than the first plurality of staple fibers, or a combination thereof. Furthermore, in one aspect, the nonwoven web exhibits: a water capacity of about 200% to about 800%, a cup crush load of less than about 100 grams, when measured using a 34 gsm nonwoven web, a bacterial filtration efficiency of about 80% or greater, or a combination thereof. In an aspect, the base sheet exhibits a 10% or greater improvement in one or more of water capacity, cup crush load, or bacterial filtration, as compared to the same nonwoven web that does not include the plurality of staple fibers

The present disclosure is also generally directed to a method of forming a base sheet. The method includes forming a nonwoven web that extends in a first plane, applying an adhesive to a first surface of the nonwoven web, and adhering a plurality of staple fibers to the nonwoven web. In such an aspect, at least a portion of the plurality of staple fibers extend in one or more second planes that are not parallel to the first plane, and have a length of 5000 micrometers or less, a denier of 5 or less, or a combination thereof.

In another aspect, the adhesive includes an anionic component, where the anionic component and the adhesive are printed on the nonwoven web. In yet a further aspect, the anionic component and the adhesive are flexographically printed onto the nonwoven web and the plurality of staple fibers are electrostatically adhered to the nonwoven web. Additionally or alternatively, the base sheet is calendared.

Other features and aspects of the present disclosure are discussed in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

Fig. 1 illustrates a cross-sectional view of an aspect of a base sheet according to the present disclosure;

Fig. 2 illustrates a cross-sectional view of an aspect of a base sheet according to the present discosure; and

Fig. 3 illustrates a method of forming a base sheet according to the present disclosure.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DEFINITIONS

The terms "about," "approximately,” or "generally,”, when used herein to modify a value, indicates that the value can be raised or lowered by 10%, such as 7.5%, such as 5%, such as 4%, such as 3%, such as 2%, or such as 1%, and remain within the disclosed aspect.

The term "fiber” as used herein refers to an elongate particulate having an apparent length greatly exceeding its apparent width, i.e. a length to diameter ratio of at least about 10. More specifically, as used herein, fiber refers to papermaking fibers. The present invention contemplates the use of a variety of papermaking fibers, such as, for example, natural fibers or synthetic fibers, or any other suitable fibers, and any combination thereof. Papermaking fibers useful in the present invention include cellulosic fibers commonly and more particularly wood pulp fibers.

The term "nonwoven web” generally refers to a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Examples of suitable nonwoven fabrics or webs include, but are not limited to, meltblown webs, spunbond webs, bonded carded webs, airlaid webs, coform webs, hydraulically entangled webs, and so forth.

The term "meltblown web” generally refers to a nonwoven web that is formed by a process in which a molten thermoplastic material is extruded through a plurality of fine, usually circular, die capillaries as molten fibers into converging high velocity gas (e.g., air) streams that attenuate the fibers of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. Such a process is disclosed, for example, in U.S. Patent No. 3,849,241 to Butin, et al., which is incorporated herein in its entirety by reference thereto for all purposes. Generally speaking, meltblown fibers may be microfibers that are substantially continuous or discontinuous, generally smaller than 10 microns in diameter, and generally tacky when deposited onto a collecting surface.

The term "spunbond web” generally refers to a web containing small diameter substantially continuous fibers. The fibers are formed by extruding a molten thermoplastic material from a plurality of fine, usually circular, capillaries of a spinnerette with the diameter of the extruded fibers then being rapidly reduced as by, for example, eductive drawing and/or other well-known spunbonding mechanisms. The production of spunbond webs is described and illustrated, for example, in U.S. Patent Nos. 4,340,563 to Appel, et al., 3,692,618 to Dorschner, et al., 3,802,817 to Matsuki, et al., 3,338,992 to Kinney, 3,341 ,394 to Kinney, 3,502,763 to Hartman, 3,502,538 to Levy, 3,542,615 to Dobo, et al., and 5,382,400 to Pike, et al., which are incorporated herein in their entirety by reference thereto for all purposes. Spunbond fibers are generally not tacky when they are deposited onto a collecting surface. Spunbond fibers may sometimes have diameters less than about 40 microns, and are often between about 5 to about 20 microns.

The term "coform" generally refers to composite materials comprising a mixture or stabilized matrix of thermoplastic fibers and a second non-thermoplastic material. As an example, coform materials may be made by a process in which at least one meltblown die head is arranged near a chute through which other materials are added to the web while it is forming. Such other materials may include, but are not limited to, fibrous organic materials such as woody or non-woody pulp such as cotton, rayon, recycled paper, pulp fluff and also superabsorbent particles, inorganic and/or organic absorbent materials, treated polymeric staple fibers and so forth. Some examples of such coform materials are disclosed in U.S. Patent Nos. 4,100,324 to Anderson, et al., 5,284,703 to Everhart, et al., and 5,350,624 to Georger, et al., each of which are incorporated herein in their entirety by reference thereto for all purposes.

The term "bonded carded web" refers to webs made from staple fibers which are sent through a combing or carding unit, which breaks apart and aligns the staple fibers in the machine direction to form a generally machine direction-oriented fibrous nonwoven web. Such fibers are usually purchased in bales which are placed in a picker or fiberizer which separates the fibers prior to the carding unit. Once the web is formed, it is then bonded by one or more of several known bonding methods.

The term "elastomeric” and "elastic” and refers to a material that, upon application of a stretching force, is stretchable in at least one direction (such as the CD direction), and which upon release of the stretching force, contracts/returns to approximately its original dimension. For example, a stretched material may have a stretched length that is at least 50% greater than its relaxed unstretched length, and which will recover to within at least 50% of its stretched length upon release of the stretching force. A hypothetical example would be a one (1) inch sample of a material that is stretchable to at least 1 .50 inches and which, upon release of the stretching force, will recover to a length of not more than 1 .25 inches. Desirably, the material contracts or recovers at least 50%, and even more desirably, at least 80% of the stretched length.

The term "thermal point bonding” generally refers to a process performed, for example, by passing a material between a patterned roll (e.g., calender roll) and another roll (e.g., anvil roll), which may or may not be patterned. One or both of the rolls are typically heated.

The term "ultrasonic bonding” generally refers to a process performed, for example, by passing a material between a sonic horn and a patterned roll (e.g., anvil roll). For instance, ultrasonic bonding through the use of a stationary horn and a rotating patterned anvil roll is described in U.S. Patent Nos. 3,939,033 to Grgach, et al., 3,844,869 to Rust Jr., and 4,259,399 to Hill, which are incorporated herein in their entirety by reference thereto for all purposes. Moreover, ultrasonic bonding through the use of a rotary horn with a rotating patterned anvil roll is described in U.S. Patent Nos. 5,096,532 to Neuwirth, et al., 5,110,403 to Ehlert, and 5,817,199 to Brennecke, et al., which are incorporated herein in their entirety by reference thereto for all purposes. Of course, any other ultrasonic bonding technique may also be used in the present invention.

The term "slurry” as used herein refers to a mixture comprising fibers and water. The term "absorbent article” or "article” when used herein refers to products made from fibrous webs which includes, but is not limited to, personal care absorbent articles, such as baby wipes, mitt wipes, diapers, pant diapers, open diapers, training pants, absorbent underpants, incontinence articles, feminine hygiene products (e.g., sanitary napkins), swim wear and so forth; medical absorbent articles, such as garments, fenestration materials, underpads, bedpads, bandages, absorbent drapes, and medical wipes; food service wipers; clothing articles; pouches, and so forth. Materials and processes suitable for forming such articles are well known to those skilled in the art. An absorbent article, for example, can include a liner, an outer cover, and an absorbent material or pad formed from a fibrous web positioned therebetween.

The term "wiping product” as used herein refers to products made from fibrous webs and includes paper towels, industrial wipers, foodservice wipers, napkins, medical pads, and other similar products. It should be understood that, in one aspect, a wiping product may be included when referring to an absorbent article or absorbent web according to the present disclosure.

As used herein, the term "basis weight” generally refers to the dry weight per unit area of a fibrous product and is generally expressed as grams per square meter (gsm). Basis weight is measured using TAPPI test method T-220.

The term "machine direction" as used herein refers to the direction of travel of the forming surface onto which fibers are deposited during formation of a nonwoven web.

The term "cross-machine direction" as used herein refers to the direction which is perpendicular to the machine direction defined above and in the plane of the forming surface.

The term "pulp" as used herein refers to fibers from natural sources such as woody and non- woody plants. Woody plants include, for example, deciduous and coniferous trees. Non-woody plants include, for example, cotton, flax, esparto grass, milkweed, straw, jute, hemp, and bagasse. Pulp fibers can include hardwood fibers, softwood fibers, and mixtures thereof.

The term "average fiber length" as used herein refers to an average length of fibers, fiber bundles and/or fiber-like materials determined by measurement utilizing microscopic techniques. A sample of at least 20 randomly selected fibers is separated from a liquid suspension of fibers. The fibers are set up on a microscope slide prepared to suspend the fibers in water. A tinting dye is added to the suspended fibers to color cellulose-containing fibers so they may be distinguished or separated from synthetic fibers. The slide is placed under a Fisher Stereomaster II Microscope-S19642/S19643 Series. Measurements of 20 fibers in the sample are made at 20X linear magnification utilizing a 0-20 mils scale and an average length, minimum and maximum length, and a deviation or coefficient of variation are calculated. In some cases, the average fiber length will be calculated as a weighted average length of fibers (e.g., fibers, fiber bundles, fiber-like materials) determined by equipment such as, for example, a Kajaani fiber analyzer Model No. FS-200, available from Kajaani Oy Electronics, Kajaani, Finland. According to a standard test procedure, a sample is treated with a macerating liquid to ensure that no fiber bundles or shives are present. Each sample is disintegrated into hot water and diluted to an approximately 0.001% suspension. Individual test samples are drawn in approximately 50 to 100 ml portions from the dilute suspension when tested using the standard Kajaani fiber analysis test procedure. The weighted average fiber length may be an arithmetic average, a length weighted average or a weight weighted average and may be expressed by the following equation: where k=maximum fiber length

XFfiber length n/=number of fibers having length xi n=total number of fibers measured.

One characteristic of the average fiber length data measured by the Kajaani fiber analyzer is that it does not discriminate between different types of fibers. Thus, the average length represents an average based on lengths of all different types, if any, of fibers in the sample.

The term "staple fibers" means discontinuous fibers made from synthetic polymers such as polypropylene, polyester, post consumer recycle (PCR) fibers, polyester, nylon, and the like, and those not hydrophilic may be treated to be hydrophilic. Staple fibers may be cut fibers or the like. Staple fibers can have cross-sections that are round, bicomponent, multicomponent, shaped, hollow, or the like.

As used herein, the term "abrasive" is intended to represent a surface texture which enables the nonwoven web to scour a surface being wiped or cleaned with the nonwoven web and remove dirt and the like. The abrasiveness can vary depending on the polymer used to prepare the abrasive fibers and the degree of texture of the nonwoven web.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary aspects only, and is not intended as limiting the broader aspects of the present disclosure.

Generally speaking, the present disclosure is directed to a base sheet having a microstructured topography that is formed from a nonwoven web and at least a first plurality of staple fibers adhered to a first side of the nonwoven web. Particularly, the present disclosure has found that by carefully selecting staple fibers and adhering the staple fibers to the nonwoven web such that the staple fibers extend in a direction generally non-planar with the nonwoven web, one or more properties of the base sheet can be improved without impacting the properties of the nonwoven web, and without the need for altering the composition of the nonwoven web. Furthermore, in one aspect, the present disclosure has found that a second plurality of staple fibers can be adhered to a second side of the nonwoven web. In such an aspect, the second plurality of staple fibers can be different in size, shape, or properties (such as water absorbency, oil absorbency, etc) than the first plurality of fibers, providing the base sheet with different properties on each of its surfaces, without requiring change in composition or treatment of the nonwoven web.

For instance, in one aspect, the first and/or second plurality of staple fibers may be selected to improve one or more properties of the nonwoven web, such as water absorbency, oil absorbency, softness, abrasiveness, durability, barrier properties or the like. For instance, a staple fiber may be selected based upon the material's ability to improve these properties, and can be formed from one or more synthetic fibers. In one aspect, the staple fiber(s) can be formed from polypropylene, polyester, post consumer recycle (PCR) fibers, pre-consumer (e.g. post industrial) recycle fibers, rayon, polyester, nylon, and the like. In one aspect, the fibers can be formed from polypropylene, polyester, rayon, nylon, or a combination thereof. While a fiber inherently have one or more of the above properties may be selected, it should be understood that, in one aspect, the fiber(s) selected may be treated to impart, or increase their hydrophobicity, absorbency, or others as known in the art. However, in one aspect, the staple fibers can also include cellulosic fibers, such as cotton, including fibers from waste and recycling, including agro-industrial and textile waste.

Nonetheless, in one aspect, one or more of the above materials may be used to form the staple fibers, and the length and/or denier of the fiber may be altered to impart further advantages. For instance, shorter and/or thinner (e.g. lower denier) fibers can provide a softer surface whereas longer and/or thicker (e.g. higher denier) fibers can improve abrasiveness or durability. Thus, in one aspect, the first and/or second plurality of staple fibers can have a denier of about 20 or less, such as about 17.5 or less, such as about 15 or less, such as about 12.5 or less, such as about 10 or less, such as about 8 or less, such as about 6 or less, such as about 5 or less, such as about 4 or less, such as about 3 or less, such as about 2 or less, or any ranges or values therebetween.

Furthermore, additionally or alternatively, the fibers may have a length, which is the staple fiber's longest dimension, of about 10 micrometers to about 5000 micrometers, such as about 50 micrometers to about 4000 micrometers, such as about 100 micrometers to about 3000 micrometers, such as about 150 micrometers to about 2000 micrometers, such as about 200 micrometers to about 1000 micrometers, such as about 250 micrometers toa bout 750 micrometers, or any ranges or values therebetween.

Furthermore, in one aspect, a staple fiber providing softness may have a denier of about 4 or less, such as about 3.5 or less, such as about 3 or less, such as about 2.5 or less, such as about 2 or less, such as about 1 .5 or less, such as about 1 or less, such as about 0.9 or less, such as about 0.8 or less, or any ranges or values therebetween, and/or a length of about 2000 micrometers or less, such as about 1750 micrometers or less, such as about 1500 micrometers or less, such as about 1000 micrometers or less, such as about 500 micrometers or less. For instance, in one aspect, soft fibers have a denier of about 2.5 to about 3.5 and a length of about 1000 micrometers to about 1700 micrometers, a denier of about 1 to about 2 and a length of about 500 micrometers to about 1500 micrometers, a denier of about 0.5 to about 1 , and a length of about 250 micrometers to about 1000 micrometers, or any ranges or values therebetween.

Similarly, a fiber having good abrasiveness or wear properties may have a denier of about 4 or greater, such as about 5 or greater, such as about 7.5 or greater, such as about 10 or greater, such as about 15 or greater, such as about 20 or greater, such as about 25 or greater, such as about 30 or greater, such as about 35 or greater, such as about 45 or less, such as about 40 or less, such as about 35 or less, such as about 30 or less, such as about 25 or less, or any ranges or values therebetween, and/or a length of about 10 millimeters or less, such as about 9 millimeters or less, such as about 8 millimeters or less, such as about 7 millimeters or less, such as about 6000 micrometers or less, such as about 5000 micrometers or less, such as about 4000 micrometers or less, such as about 3000 micrometers or less, such as about 2000 micrometers or less, such as about 1200 micrometers or greater, such as about 1300 micrometers or greater, such as about 1400 micrometers or greater, such as about 1500 micrometers or greater, or any values or ranges therebetween. For instance, in one aspect, an abrasive fiber has a denier of about 5 to about 7 and a length of about 1250 micrometers to about 4000 micrometers, a denier of about 9.5 to about 12 and a length of about 2500 micrometers to about 5500 micrometers, a denier of about 19 to about 21 and a length of about 4500 micrometers to about 7500 micrometers, a denier of about 38 to about 41 and a length of about 6500 micrometers to about 10,000 micrometers, or any ranges or values therebetween.

Regardless of the type and size of fibers selected, the fibers are treated with a cation. In one aspect, the cation is incorporated during formation of the staple fibers, however, it should be understood that the cation can be incorporated into the staple fibers after formation, such as by treating the staple fibers. In one aspect, the cation is a metal cation, such as an alkali metal cation, and, in one aspect, may be selected from potassium, sodium, lithium, or a combination thereof. In one aspect, a suitable cationically charged fibers can be obtained as treated staple fibers from Agatex.

Particularly, in one aspect, as discussed above, the plurality of fibers are attached to the nonwoven web via an adhesive after being exposed to a magnetic field. As will be discussed in greater detail below, the adhesive can be applied to the nonwoven web using a variety of techniques, including printing, spraying, dipping, and the like. Nonetheless, in one aspect, the adhesive may be any adhesive known in the art, but may be treated with an anion. Thus, as will be discussed in greater detail below, the plurality of fibers may be plated or deposited on the nonwoven web due to the attraction between the cation incorporated into or onto the fibers, and the anionic component incorporated into the adhesive. While any anion known in the art may be used, in one aspect, the anion is an anion with suitable attraction to a metal cation, such as an alkali metal cation. Thus, in one aspect, the anion can include a mineral anion, such as chlorine, bromine, iodine, or a fluorinated salt anion, such as PFe ", SCN", CIO4 ", CF3SO3 ", (FSO2)2N", (CFsSC ^N", (C2F5SO2)2N", and (CF ₃ SO2)3C", or a combination thereof. In one aspect, a suitable anionically treated adhesive can be obtained from Agatex.

Notwithstanding the adhesive selected, in one aspect, the fibers are adhered to one or more surfaces of the nonwoven web via the adhesive. For instance, referring to Fig. 1 , a nonwoven web 102 can have an adhesive 104 applied thereon, and a first plurality of staple fibers 106 affixed to the nonwoven web via the adhesive to form a base web 100 having a microstructured topography. Moreover, referring to Fig. 2, and as discussed above, in one aspect, the first plurality of staple fibers are affixed to a first side 108 of the nonwoven web, and a second plurality of staple fibers 114 are affixed to a second side 110 of the nonwoven web 102 via adhesive 112. In one aspect, the first plurality of staple fibers 106 may be the same or different than the second plurality of staple fibers 114 as discussed above. Similarly, in one aspect, the adhesive 112 may be the same or different than adhesive 104. For instance, in one aspect, the adhesive itself may be generally the same or similar, but adhesive 104 may be treated with a different anion that adhesive 112. However, in one aspect, adhesive 104 is the same, or generally the same, as adhesive 112.

Further, while the adhesive 104 and/or 112 is shown in Figs. 1 and 2 as covering the entire nonwoven web 102, it should be understood that, in some aspects, that the adhesive may be applied to about 50% or more of the nonwoven web, such as about 60% or more, such as about 70% or more, such as about 75% or more such as about 80% or more, such as about 85% or more, such as about 90% or more, such as about 95% or more, such as about 100% or less, such as about 99% or less, such as about 95% or less, such as about 90% or less, such as about 85% or less, such as ab out 80% or less of the first and/or second surface of the nonwoven web, or any ranges or values therebetween. Thus, in one aspect, the adhesive may be applied in a pattern, such as dots, squares, lines, and the like.

Nonetheless, as shown in Figs. 1 and 2, the first and/or second plurality of staple fibers 106/114 extend along their length (e.g. largest dimension from the surface of the nonwoven web to a distal end of the staple fiber) in one or more planes which are not planar with or parallel to nonwoven web 102. Particularly, as shown, in one aspect, and for example only, nonwoven web 102 extends in a generally horizontal direction along the x-axis, whereas staple fibers 106/116 extend in a variety of second planes that are not planar with, or parallel to the x-axis, forming a microstructured topography on the first and/or second surface of the nonwoven web. It should be understood that, due to the process of attaching the fibers, which will be discussed in greater detail below, some staple fibers 106/114 may become attached such that the length extends generally parallel to nonwoven web 102, however, at least a portion, such as about 50% or more, such as about 60% or more, such as about 70% or more, such as about 75% or more, such as about 80% or more, of the fibers may extend in one or more second planes that are not planar with or parallel to the first plane in which nonwoven web 102 extends. Thus, the first or second plurality of staple fibers are further distinguished from an outer layer in a laminate or layered nonwoven configuration.

Furthermore, the present disclosure has surprisingly found that the plurality of staple fibers do not diminish the underlying properties of the base web, and can, in fact, increase one or more of absorbency, abrasiveness, softness, barrier properties or the like.

For instance, in one aspect, the nonwoven web may be capable of absorbing between 3.5 and 6.0 grams of water per gram of nonwoven web. In certain exemplary aspects, the water capacity of the nonwoven web, determined by measuring the increase in the weight of a material sample resulting from the absorption of a liquid, may be between about 200% to about 800%, such as about 250% to about 750%, such as about 300% to about 700%, such as about 350% to about 600%, or any ranges or values therebetween. Further, the nonwoven web may be capable of absorbing between 3.7 and 4.3 grams of water in an amount of time between about 1 second and about 2 seconds, such as about 1 .1 seconds to about 1 .9 seconds, such as about 1 .2 seconds to about 1 .8 seconds, such as about 1 .25 to about 1 .6 second, or any ranges or values therebetween. Moreover, as discussed above, it was unexpectedly found that by forming the base sheet according to the present disclosure, the properties of the nonwoven web may be maintained at the above levels, or even increased if a fiber improving absorbency is selected.

In one aspect, the nonwoven web may also exhibit good barrier properties, and may filter at least about 70% or more of airborne particles having a size of about 0.65 microns or greater according to EN 13274-7 (utilizing a Sodium Chloride aerosol have a particle size of 0.65 microns and a velocity of 95 liters/minute over an area of 100 cm), such as about 75% or more, such as about 80% or more, such as about 85% or more, such as about 90% or more of particles having a size of about 0.65 microns or greater. Similarly, these barrier properties may be exhibited while maintaining good air permeability through the nonwoven web. For instance, the nonwoven web can exhibit an air permeability measured according to ASTM D737 (2020, measured using a 38 cm ² sample and a pressure of 125 Pa) of about 20 cfm or greater, such as about 25 cfm or greater, such as about 30 cfm or greater, such as about 32.5 cfm or greater, such as about 35 cfm or greater, such as about 40 cfm or greater, or any ranges or values therebetween. Additionally or alternatively, the nonwoven web may exhibit a bacterial filtration efficiency (BCE), the test for which is defined below, of about 80% or greater, such as about 85% or greater, such as about 90% or greater, such as about 95% or greater.

The nonwoven web may also have softness measured as cup crush energy, of less than about 1500 gm-mm, such as about 1400 gm-mm or less, such as about 1300 gm-mm or less, such as about 1200 gm-mm or less, and cup crush load of less than about 100 grams, such as about 95 grams, such as about 90 grams, such as about 85 grams, such as about 80 grams, such as about 75 grams, such as about 70 grams, when testing a 34 gsm web according to the cup crush test set forth below.

Furthermore, the present disclosure has found that these properties can be maintained or even improved by incorporating staple fibers according to the present disclosure. For instance, one or more of the above properties may be improved by about 10% of the above values or more, such as about 20%, such as about 30%, such as about 40%, such as about 50% or more based upon the fiber, denier, and length selected. Furthermore, in one aspect, a property that is not inherent to the nonwoven web may be imparted to the nonwoven web/base sheet by incorporating a fiber having one or more of the above properties without impacting (e.g. decreasing or reducing) the above discussed properties of the nonwoven web. For instance, a nonwoven web having barrier properties according to the above may be combined with fibers having high softness, improving the softness of the barrier fabric without impacting the barrier properties. In such an aspect, the base sheet may have a softness that is 10% or greater than the same nonwoven web having barrier properties that has not been treated with a plurality of staple fibers, such as about 15% or greater, such as about 20% or greater, such as about 25% or greater. Similarly, in one aspect, an absorbent nonwoven web may be treated with abrasive fibers which increase the abrasiveness by about 10% or more than the same absorbent nonwoven web that has not been treated with a plurality of staple fibers, such as about 15% or greater, such as about 20% or greater, such as about 25% or greater. Moreover, in one aspect, a nonwoven web having water or oil absorbency may contain a plurality of fibers to improve the other of water or oil absorbency, such that a first side of the nonwoven web may be oil absorbent and the opposite be water absorbent. For instance, the absorbent nonwoven web may be treated with oil or water absorbent fibers which increase the respective absorbency by about 10% or more than the same absorbent nonwoven web that has not been treated with a plurality of staple fibers, such as about 15% or greater, such as about 20% or greater, such as about 25% or greater. Of course, as noted above, it should be understood that a first plurality of fibers may be adhered to a first side of the nonwoven wed, and a second plurality may be adhered to a second side of the nonwoven web, such that two or more of the above properties may be improved while maintaining, if not improving, the properties of the nonwoven web.

The nonwoven web may be formed from one or more of a variety of polymers that can be used in forming the nonwoven web material can include olefins (e.g., polyethylenes and polypropylenes), polyesters (e.g., polybutylene terephthalate, polybutylene naphthalate), polyamides (e.g., nylons), polycarbonates, polyphenylene sulfides, polystyrenes, polyurethanes (e.g., thermoplastic polyurethanes), etc. In one particular embodiment, the fibers of the nonwoven web material can include an olefin homopolymer. One suitable olefin homopolymer is a propylene homopolymer having a density of 0.91 grams per cubic centimeter (g/cm ³ ), a melt flow rate of 1200 g/10 minute (230°C, 2.16 kg), a crystallization temperature of 113°C, and a melting temperature of 156°C, and is available as METOCENE MF650X polymer from LyondellBasell Industries in Rotterdam, The Netherlands. Another suitable propylene homopolymer that can be used has a density of 0.905 g/cm ³ , a melt flow rate of 1300 g/10 minute (230°C, 2.16 kg), and a melting temperature of 165°C, and is available as Polypropylene 3962 from Total Petrochemicals in Houston, Texas. Another suitable polypropylene is available as EXXTRAL™ 3155, available from ExxonMobil Chemical Company of Houston, Texas.

Further, a variety of thermoplastic elastomeric and plastomeric polymers may generally be employed in the nonwoven web material of the present invention, such as elastomeric polyesters, elastomeric polyurethanes, elastomeric polyamides, elastomeric copolymers, elastomeric polyolefins, and so forth. In one particular embodiment, elastomeric semi-crystalline polyolefins are employed due to their unique combination of mechanical and elastomeric properties. Semi-crystalline polyolefins have or are capable of exhibiting a substantially regular structure. For example, semi-crystalline polyolefins may be substantially amorphous in their undeformed state, but form crystalline domains upon stretching. The degree of crystallinity of the olefin polymer may be from about 3% to about 60%, in some embodiments from about 5% to about 45%, in some embodiments from about 5% to about 30%, and in some embodiments, from about 5% and about 15%. Likewise, the semi-crystalline polyolefin may have a latent heat of fusion (AHf), which is another indicator of the degree of crystallinity, of from about 15 to about 210 Joules per gram (" J/g”), in some embodiments from about 20 to about 100 J/g, in some embodiments from about 20 to about 65 J/g, and in some embodiments, from 25 to about 50 J/g. The semi-crystalline polyolefin may also have a Vicat softening temperature of from about 10°C to about 100°C, in some embodiments from about 20°C to about 80°C, and in some embodiments, from about 30°C to about 60°C. The semi-crystalline polyolefin may have a melting temperature of from about 20°C to about 120°C, in some embodiments from about 35°C to about 90°C, and in some embodiments, from about 40°C to about 80°C. The latent heat ef fusion (AHf) and melting temperature may be determined using differential scanning calorimetry ("DSC”) in accordance with ASTM D-3417 as is well known to those skilled in the art. The Vicat softening temperature may be determined in accordance with ASTM D-1525.

Exemplary semi-crystalline polyolefins include polyethylene, polypropylene, as well as their blends and copolymers thereof. In one particular embodiment, a polyethylene is employed that is a copolymer of ethylene and an a-olefin , such as a C3-C20 a-olefin or C3-C12 a-olefin. Suitable a- olefins may be linear or branched (e.g., one or more C1-C3 alkyl branches, or an aryl group). Specific examples include 1 -butene; 3-methyl-1 -butene; 3, 3-dimethyl-1 -butene; 1 -pentene; 1 -pentene with one or more methyl, ethyl or propyl substituents; 1-hexene with one or more methyl, ethyl or propyl substituents; 1 -heptene with one or more methyl, ethyl or propyl substituents; 1 -octene with one or more methyl, ethyl or propyl substituents; 1-nonene with one or more methyl, ethyl or propyl substituents; ethyl, methyl or dimethyl-substituted 1-decene; 1-dodecene; and styrene. Particularly desired a-olefin comonomers are 1 -butene, 1-hexene, and 1 -octene. The ethylene content of such copolymers may be from about 60 mole% to about 99 mole%, in some embodiments from about 80 mole% to about 98.5 mole%, and in some embodiments, from about 87 mole% to about 97.5 mole%. The a-olefin content may likewise range from about 1 mole% to about 40 mole%, in some embodiments from about 1 .5 mole% to about 15 mole%, and in some embodiments, from about 2.5 mole% to about 13 mole%.

The density of the polyethylene may vary depending on the type of polymer employed, but generally ranges from about 0.85 g/cm ³ to about 0.96 g/cm ³ . Polyethylene "plastomers”, for instance, may have a density in the range of from 0.85 g/cm ³ to 0.91 g/cm ³ . Likewise, "linear low density polyethylene” ("LLDPE”) may have a density in the range of from about 0.91 g/cm ³ to about 0.94 g/cm ³ ; "low density polyethylene” ("LDPE”) may have a density in the range of from about 0.91 g/cm ³ to about 0.94 g/cm ³ ; and "high density polyethylene” ("HDPE”) may have density in the range of from 0.94 g/cm ³ to 0.96 g/cm ³ . Densities may be measured in accordance with ASTM 1505.

Particularly suitable polyethylene copolymers are those that are "linear” or "substantially linear.” The term "substantially linear” means that, in addition to the short chain branches attributable to comonomer incorporation, the ethylene polymer also contains long chain branches in the polymer backbone. "Long chain branching” refers to a chain length of at least 6 carbons. Each long chain branch may have the same comonomer distribution as the polymer backbone and be as long as the polymer backbone to which it is attached. Preferred substantially linear polymers are substituted with from 0.01 long chain branch per 1000 carbons to 1 long chain branch per 1000 carbons, and in some embodiments, from 0.05 long chain branch per 1000 carbons to 1 long chain branch per 1000 carbons. In contrast to the term "substantially linear”, the term "linear” means that the polymer lacks measurable or demonstrable long chain branches. That is, the polymer is substituted with an average of less than 0.01 long chain branch per 1000 carbons.

The density of a linear ethylene/a-olefin copolymer is a function of both the length and amount of the a-olefin. That is, the greater the length of the a-olefin and the greater the amount of a-olefin present, the lower the density of the copolymer. Although not necessarily required, linear polyethylene "plastomers” are particularly desirable in that the content of a-olefin short chain branching content is such that the ethylene copolymer exhibits both plastic and elastomeric characteristics - i.e., a "plastomer.” Because polymerization with a-olefin comonomers decreases crystallinity and density, the resulting plastomer normally has a density lower than that of polyethylene thermoplastic polymers (e.g., LLDPE), but approaching and/or overlapping that of an elastomer. For example, the density of the polyethylene plastomer may be 0.91 g/cm ³ or less, in some embodiments, from about 0.85 g/cm ³ to about 0.88 g/cm ³ , and in some embodiments, from about 0.85 g/cm ³ to about 0.87 g/cm ³ . Despite having a density similar to elastomers, plastomers generally exhibit a higher degree of crystallinity and may be formed into pellets that are non-adhesive and relatively free flowing.

The distribution of the a-olefin comonomer within a polyethylene plastomer is typically random and uniform among the differing molecular weight fractions forming the ethylene copolymer. This uniformity of comonomer distribution within the plastomer may be expressed as a comonomer distribution breadth index value (“CDBI”) of 60 or more, in some embodiments 80 or more, and in some embodiments, 90 or more. Further, the polyethylene plastomer may be characterized by a DSC melting point curve that exhibits the occurrence of a single melting point peak occurring in the region of 50 to 110°C (second melt rundown).

Preferred plastomers for use in the present invention are ethylene-based copolymer plastomers available under the designation EXACT™ from ExxonMobil Chemical Company of Houston, Texas. Other suitable polyethylene-based plastomers are available under the designation ENGAGE™ and AFFINITY™ from Dow Chemical Company of Midland, Michigan. An additional suitable polyethylene-based plastomer is an olefin block copolymer available from Dow Chemical Company of Midland, Michigan under the trade designation INFUSE™, such as INFUSE™ 9807. A polyethylene that can be used in the fibers of the present invention is DOW™ 61800.41 . Still other suitable ethylene polymers are available from The Dow Chemical Company under the designations DOWLEX™ (LLDPE), ASPUN™ (LLDPE), and ATTANE™ (ULDPE). Other suitable ethylene polymers are described in U.S. Patent Nos. 4,937,299 to Ewen et al.; 5,218,071 to Tsutsui et al.; 5,272,236 to Lai, et al.; and 5,278,272 to Lai, et al., which are incorporated herein in their entirety by reference thereto for all purposes.

Of course, the present invention is by no means limited to the use of ethylene polymers. For instance, propylene polymers may also be suitable for use as a semi-crystalline polyolefin. Suitable plastomeric propylene polymers may include, for instance, copolymers or terpolymers of propylene include copolymers of propylene with an a-olefin (e.g., C3-C20), such as ethylene, 1 -butene, 2-butene, the various pentene isomers, 1 -hexene, 1 -octene, 1 -nonene, 1 -decene, 1 -unidecene, 1 -dodecene, 4- methyl-1 -pentene, 4-methyl-1 -hexene, 5-methyl-1 -hexene, vinylcyclohexene, styrene, etc. The comonomer content of the propylene polymer may be about 35 wt.% or less, in some embodiments from about 1 wt.% to about 20 wt.%, and in some embodiments, from about 2 wt.% to about 10 wt.%. Preferably, the density of the polypropylene (e.g., propylene/a-olefin copolymer) may be 0.91 grams per cubic centimeter (g/cm ³ ) or less, in some embodiments, from 0.85 to 0.88 g/cm ³ , and in some embodiments, from 0.85 g/cm ³ to 0.87 g/cm ³ . Suitable propylene-based copolymer plastomers are commercially available under the designations VISTAMAXX™ (e.g., 2330, 6202, and 6102), a propylene-ethylene copolymer-based plastomer from ExxonMobil Chemical Co. of Houston, Texas; Fl NA™ (e.g., 8573) from Atofina Chemicals of Feluy, Belgium; TAFMER™ available from Mitsui Petrochemical Industries; and VERSIFY™ available from Dow Chemical Co. of Midland, Michigan. Other examples of suitable propylene polymers are described in U.S. Patent No. 6,500,563 to Datta, et al.; 5,539,056 to Yang, et al.; and 5,596,052 to Resconi, et al., which are incorporated herein in their entirety by reference thereto for all purposes.

Any of a variety of known techniques may generally be employed to form the semi-crystalline polyolefins. For instance, olefin polymers may be formed using a free radical or a coordination catalyst (e.g., Ziegler-Natta). Preferably, the olefin polymer is formed from a single-site coordination catalyst, such as a metallocene catalyst. Such a catalyst system produces ethylene copolymers in which the comonomer is randomly distributed within a molecular chain and uniformly distributed across the different molecular weight fractions. Metallocene-catalyzed polyolefins are described, for instance, in U.S. Patent. Nos. 5,571 ,619 to McAlpin et al.; 5,322,728 to Davis et al.; 5,472,775 to Obijeski et al.; 5,272,236 to Lai et al.; and 6,090,325 to Wheat, et al., which are incorporated herein in their entirety by reference thereto for all purposes. Examples of metallocene catalysts include bis(n- butylcyclopentadienyl)titanium dichloride, bis(n-butylcyclopentadienyl)zirconium dichloride, bis(cyclopentadienyl)scandium chloride, bis(indenyl)zirconium dichloride, bis(methylcyclopentadienyl)titanium dichloride, bis(methylcyclopentadienyl)zirconium dichloride, cobaltocene, cyclopentadienyltitanium trichloride, ferrocene, hafnocene dichloride, isopropyl(cyclopentadienyl,-1 -flourenyl)zirconium dichloride, molybdocene dichloride, nickelocene, niobocene dichloride, ruthenocene, titanocene dichloride, zirconocene chloride hydride, zirconocene dichloride, and so forth. Polymers made using metallocene catalysts typically have a narrow molecular weight range. For instance, metallocene-catalyzed polymers may have polydispersity numbers (M _w /M _n ) of below 4, controlled short chain branching distribution, and controlled isotacticity.

The melt flow index (Ml) of the semi-crystalline polyolefins may generally vary, but is typically in the range of about 0.1 grams per 10 minutes to about 100 grams per 10 minutes, in some embodiments from about 0.5 grams per 10 minutes to about 30 grams per 10 minutes, and in some embodiments, about 1 to about 10 grams per 10 minutes, determined at 190°C. The melt flow index is the weight of the polymer (in grams) that may be forced through an extrusion rheometer orifice (0.0825-inch diameter) when subjected to a force of 5000 grams in 10 minutes at 190°C, and may be determined in accordance with ASTM Test Method D1238-E.

Of course, other thermoplastic polymers may also be used to form nonwoven web material. For instance, a substantially amorphous block copolymer may be employed that has at least two blocks of a monoalkenyl arene polymer separated by at least one block of a saturated conjugated diene polymer. The monoalkenyl arene blocks may include styrene and its analogues and homologues, such as o-methyl styrene; p-methyl styrene; p-tert-butyl styrene; 1 ,3 dimethyl styrene p- methyl styrene; etc., as well as other monoalkenyl polycyclic aromatic compounds, such as vinyl naphthalene; vinyl anthrycene; and so forth. Preferred monoalkenyl arenes are styrene and p-methyl styrene. The conjugated diene blocks may include homopolymers of conjugated diene monomers, copolymers of two or more conjugated dienes, and copolymers of one or more of the dienes with another monomer in which the blocks are predominantly conjugated diene units. Preferably, the conjugated dienes contain from 4 to 8 carbon atoms, such as 1 ,3 butadiene (butadiene); 2-methyl-1 ,3 butadiene; isoprene; 2,3 dimethyl-1 ,3 butadiene; 1 ,3 pentadiene (piperylene); 1 ,3 hexadiene; and so forth.

The amount of monoalkenyl arene (e.g., polystyrene) blocks may vary, but typically constitute from about 8 wt.% to about 55 wt.%, in some embodiments from about 10 wt.% to about 35 wt.%, and in some embodiments, from about 25 wt.% to about 35 wt.% of the copolymer. Suitable block copolymers may contain monoalkenyl arene endblocks having a number average molecular weight from about 5,000 to about 35,000 and saturated conjugated diene midblocks having a number average molecular weight from about 20,000 to about 170,000. The total number average molecular weight of the block polymer may be from about 30,000 to about 250,000.

Particularly suitable thermoplastic elastomeric block copolymers are available from Kraton Polymers LLC of Houston, Texas under the trade name KRATON™ . KRATON™ polymers include styrene-diene block copolymers, such as styrene-butadiene, styrene-isoprene, styrene-butadiene- styrene, and styrene-isoprene-styrene. KRATON™ polymers also include styrene-olefin block copolymers formed by selective hydrogenation of styrene-diene block copolymers. Examples of such styrene-olefin block copolymers include styrene-(ethylene-butylene), styrene-(ethylene-propylene), styrene-(ethylene-butylene)-styrene, styrene-(ethylene-propylene)-styrene, styrene-(ethylene- butylene)-styrene-(ethylene-butylene), styrene-(ethylene-propylene)-styrene-(ethylene-propylene), and styrene-ethylene-(ethylene-propylene)-styrene. These block copolymers may have a linear, radial or star-shaped molecular configuration. Specific KRATON™ block copolymers include those sold under the brand names G 1652, G 1657, G 1730, MD6673, MD6703, MD6716, and MD6973. Various suitable styrenic block copolymers are described in U.S. Patent Nos. 4,663,220, 4,323,534, 4,834,738, 5,093,422 and 5,304,599, which are hereby incorporated in their entirety by reference thereto for all purposes. Other commercially available block copolymers include the S-EP-S and S-E-E-P-S elastomeric copolymers available from Kuraray Company, Ltd. of Okayama, Japan, under the trade designation SEPTON™ . Still other suitable copolymers include the S-l-S and S-B-S elastomeric copolymers available from Dexco Polymers of Houston, Texas under the trade designation VECTOR™. Also suitable are polymers composed of an A-B-A-B tetrablock copolymer, such as discussed in U.S. Patent No. 5,332,613 to Taylor, et al., which is incorporated herein in its entirety by reference thereto for all purposes. An example of such a tetrablock copolymer is a styrene- poly(ethylene-propylene)-styrene-poly(ethylene-propylene) (“S-EP-S-EP”) block copolymer.

A single polymer as discussed above can be used to form the fibers from which the nonwoven web material is comprised, and when utilized, can be utilized in amount up to 100 wt.% based on the total weight of the nonwoven web material, such as from about 75 wt.% to about 99 wt.%, such as from about 80 wt.% to about 98 wt.%, such as from about 85 wt.% to about 95 wt.%. However, in other embodiments, the nonwoven web material can include two or more polymers from the polymers discussed above. For instance, monocomponent fibers from which the nonwoven web material can include fibers formed from an olefin homopolymer in an amount ranging from about 5 wt.% to about 80 wt.%, such as from about 10 wt.% to about 75 wt.%, such as from about 15 wt.% to about 70 wt.%, based on the total weight of the nonwoven web material. Meanwhile, the fibers can also include a derivative of an olefin polymer. For instance, the nonwoven web material can include an elastomeric semi-crystalline polyolefin or "plastomer” (e.g., an ethylene/o-olefin copolymer, a propylene/o-olefin copolymer, or a combination thereof); a thermoplastic elastomeric block copolymer; or a combination thereof in an amount ranging from about 20 wt.% to about 95 wt.%, such as from about 25 wt.% to about 90 wt.%, such as from about 30 wt.% to about 85 wt.% based on the total weight of the nonwoven web material.

In additional embodiments, the fibers from which the nonwoven web material is formed can be multicomponent and can have a sheath-core arrangement or side-by-side arrangement. For instance, in a sheath-core multicomponent fiber arrangement, the sheath can include a blend of a polypropylene and a polypropylene-based plastomer, (e.g., VISTAMAXX™), while the core can include a blend of a polyethylene and a polyethylene-based plastomer (e.g., INFUSE™). On the other hand, the sheath can include a blend of a polyethylene and a polyethylene-based plastomer (e.g., INFUSE™), while the core can include a blend of a polypropylene and a polypropylene-based plastomer, (e.g., VISTAMAXX™). Further, in still other embodiments, the core can include 100% of a polyethylene or a polypropylene homopolymer.

For instance, in some embodiments, the fibers from which the nonwoven web material is formed can have a sheath-core arrangement where the sheath can include from about 20 wt.% to about 90 wt.%, such as from about 25 wt.% to about 80 wt.%, such as from about 30 wt.% to about 70 wt.% of an olefin homopolymer (e.g., polypropylene or polyethylene) based on the total weight of the sheath component of the multicomponent fiber. Meanwhile, the sheath can also include from about 10 wt.% to about 80 wt.%, such as from about 20 wt.% to about 75 wt.%, such as from about 30 wt.% to about 70 wt.% of an olefin-based plastomer (e.g., a polypropylene-based plastomer or an ethylenebased plastomer) based on the total weight of the sheath component of the multicomponent fiber.

In addition, the core can include from about 30 wt.% to about 100 wt.%, such as from about 40 wt.% to about 95 wt.%, such as from about 50 wt.% to about 90 wt.% of an olefin homopolymer (e.g., polypropylene or polyethylene) based on the total weight of the core component of the multicomponent fiber. Further, the core can include from about 0 wt.% to about 70 wt.%, such as from about 5 wt.% to about 60 wt.%, such as from about 10 wt.% to about 50 wt.% of an olefin-based plastomer (e.g., a polypropylene-based plastomer or an ethylene-based plastomer) based on the total weight of the core component of the fiber.

Further, the weight percentage of the sheath can range from about 10 wt.% to about 70 wt.%, such as from about 15 wt.% to about 65 wt.%, such as from about 20 wt.% to about 60 wt.%, based on the total weight of the fiber. Meanwhile, the weight percentage of the core can range from about 30 wt.% to about 90 wt.%, such as from about 35 wt.% to about 85 wt.%, such as from about 40 wt.% to about 80 wt.% based on the total weight of the fiber. In addition, the fibers from which the nonwoven web material is formed can have a side-by- side arrangement where two fibers are coextruded adjacent each other. In such an embodiment, the first side can include a polyethylene and a polyethylene-based plastomer, while the second side can include a polypropylene and a polypropylene-based plastomer. The polyethylene can be present in the first side in an amount ranging from about 30 wt.% to about 90 wt.%, such as from about 35 wt.% to about 80 wt.%, such as from about 40 wt.% to about 70 wt.% based on the total weight of the first side. Meanwhile, the polyethylene-based plastomer can be present in the first side in an amount ranging from about 20 wt.% to about 80 wt.%, such as from about 25 wt.% to about 70 wt.%, such as from about 30 wt.% to about 60 wt.% based on the total weight of the first side. In addition, the polypropylene can be present in the second side in an amount ranging from about 30 wt.% to about 90 wt.%, such as from about 35 wt.% to about 80 wt.%, such as from about 40 wt.% to about 70 wt.% based on the total weight of the second side. Meanwhile, the polypropylene-based plastomer can be present in the second side in an amount ranging from about 20 wt.% to about 80 wt.%, such as from about 25 wt.% to about 70 wt.%, such as from about 30 wt.% to about 60 wt.% based on the total weight of the second side.

With such fiber configurations as those discussed above, in some embodiments, a propyleneethylene copolymer can be utilized in either the sheath and/or the core or the first side and/or the second side to act as a compatibilizer and enhance bonding between the sheath and core. For instance, the propylene-ethylene copolymer can be present in the sheath in an amount ranging from about 0.5 wt.% to about 20 wt.%, such as from about 1 wt.% to about 15 wt.%, such as from about 2 wt.% to about 10 wt.% based on the total weight of the sheath. Alternatively, the propylene-ethylene copolymer can be present in the core in an amount ranging from about 0.5 wt.% to about 20 wt.%, such as from about 1 wt.% to about 15 wt.%, such as from about 2 wt.% to about 10 wt.% based on the total weight of the core.

Other additives may also be incorporated into the nonwoven web material, such as melt stabilizers, processing stabilizers, heat stabilizers, light stabilizers, antioxidants, heat aging stabilizers, whitening agents, antiblocking agents, viscosity modifiers, etc. Viscosity modifiers may also be employed, such as polyethylene wax (e.g., EPOLENE™ C-10 from Eastman Chemical). Phosphite stabilizers (e.g., IRGAFOS available from Ciba Specialty Chemicals of Tarrytown, N.Y. and DOVERPHOS available from Dover Chemical Corp, of Dover, Ohio) are exemplary melt stabilizers. In addition, hindered amine stabilizers (e.g., CHIMASSORB available from Ciba Specialty Chemicals) are exemplary heat and light stabilizers. Further, hindered phenols are commonly used as an antioxidant in the production of films. Some suitable hindered phenols include those available from Ciba Specialty Chemicals of under the trade name IRAGANOX™, such as IRGANOX™ 1076, 1010, or E 201 . When employed, such additives (e.g., antioxidant, stabilizer, etc.) may each be present in an amount from about 0.001 wt.% to about 25 wt.%, in some embodiments, from about 0.005 wt.% to about 20 wt.%, and in some embodiments, from 0.01 wt.% to about 15 wt.% of the nonwoven web material.

The polymer(s) discussed above, as well as the other optional additive components discussed above, can be formed into monocomponent or multicomponent fibers and extruded or spun to form the nonwoven web material of the present invention, which can then be used in various products such a wipe, an absorbent article, a wearable article, or the like, and discussed in more detail below. Monocomponent fibers can be formed from a polymer or a blend of polymers as well as an optional tackifier, which are compounded and then extruded from a single extruder. Meanwhile, multicomponent fibers can be formed from two or more polymers (e.g., bicomponent fibers) extruded from separate extruders, where one or more of the polymers can be compounded with a tackifier, although this is not required when one of the polymers exhibits inherent tackiness, such as VISTAMAXX™ polymers and INFUSE™ polymers. The polymers may be arranged in substantially constantly positioned distinct zones across the cross-section of the fibers. The components may be arranged in any desired configuration, such as sheath-core, side-by-side, pie, island-in-the-sea, three island, bull's eye, or various other arrangements known in the art, and so forth. Various methods for forming multicomponent fibers are described in U.S. Patent Nos. 4,789,592 to Taniguchi et al. 5,336,552 to Strack et al., 5,108,820 to Kaneko, et al., 4,795,668 to Krueqe, et al., 5,382,400 to Pike, et al., 5,336,552 to Strack, et al., and 6,200,669 to Marmon, et al., which are incorporated herein in their entirety by reference thereto for all purposes. Multicomponent fibers having various irregular shapes may also be formed, such as described in U.S. Patent Nos. 5,277,976 to Hoqle, et al., 5,162,074 to Hills, 5,466,410 to Hills, 5,069,970 to Larqman, et al., and 5,057,368 to Larqman, et al., which are incorporated herein in their entirety by reference thereto for all purposes. In addition, hollow fibers are also contemplated by the present invention, and such fibers can reduce the amount of polymer required, as well as the basis weight of the resulting nonwoven web material.

In any event, whether the nonwoven web material is formed by meltblowing, spunbonding, or any other nonwoven web material technique, when a tackifier and/or any optional additives are compounded with one or more polymers However, it is also to be understood that, in some embodiments, the core can be a blend of two or more polymers such as polypropylene and a VISTAMAXX™ plastomer, while the sheath can also be a blend of two or polymers such as polyethylene and an INFUSE™ plastomer. Generally, the composition of the core can be chosen such that the resulting overall material is cloth-like, drapable, and soft, while the composition of the sheath can be chosen such that the sheath provides the level of tackiness needed for efficient dirt removal without the user experiencing stick and slip motion, while at the same time leaving no residue. Various embodiments of forming the fibers and nonwoven web material of the present invention will now be described in greater detail. Of course, it should be understood that the description provided below is merely exemplary, and that other methods of forming nonwoven web materials are contemplated by the present Disclosure. Particularly, the nonwoven web material can be formed from meltblown fibers or by other methods than meltblowing, such as spunbonding. One advantage of forming the nonwoven web material by spunbonding is that higher molecular weight polymers can be utilized as compared to the polymers used to form a meltblown nonwoven web material because the size of the capillary dies used in spunbonding equipment is larger than in meltblowing equipment. However, it is also to be understood that in the case of forming a meltblown nonwoven web material, the size of the capillary of the melt blown die can be increased to accommodate high viscosity (e.g., high molecular weight. Generally, however, the melt flow rate of the polymers of the present invention can range from about 3 grams per 10 minutes to about 50 grams per 10 minutes when subjected to a load of 2160 grams at a temperature of 190°C according to ASTM Test Method D1238-E. As such, in forming spunbond nonwoven web materials, polymers having higher viscosity and crystallinity can be used. For instance, polypropylene having a melt flow rate of from about 15 grams per 10 minutes to about 50 grams per 10 minutes, such as from about 20 grams per 10 minutes to about 35 grams per 10 minutes; olefinic block copolymer plastomers having a melt flow rate of from about 3 grams per 10 minutes to about 20 grams per 10 minutes, such as from about 10 grams per 10 minutes to about 15 grams per 10 minutes; and polyethylenes having a melt flow rate of from about 5 grams per 10 minutes to about 30 grams per 10 minutes, such as from about 10 grams per 10 minutes to about 25 grams per 10 minutes can be utilized.

If desired, the nonwoven web material may have a multi-layer structure. Suitable multilayered materials may include, for instance, spunbond/meltblown/spunbond (SMS) laminates and spunbond/meltblown (SM) laminates, where the spunbond and meltblown layers are formed generally as discussed above. However, in one aspect, the present disclosure includes nonwoven webs and/or base sheets that are free of SMS laminates. Particularly, as discussed above, nonwoven webs according to the present disclosure may instead have properties introduced to the nonwoven web via the adhered staple fibers, and may therefore not require any of the traditional benefits associated with SMS laminates.

Another example of a nonwoven web material that is contemplated by the present invention is a spunbond web produced on a multiple spin bank machine in which a spin bank deposits fibers over a layer of fibers deposited from a previous spin bank. Such an individual spunbond nonwoven web may also be thought of as a multi-layered structure. In this situation, the various layers of deposited fibers in the nonwoven web may be the same, or they may be different in basis weight and/or in terms of the composition, type, size, level of crimp, and/or shape of the fibers produced. As another example, a single nonwoven web may be provided as two or more individually produced layers of a spunbond web, a carded web, etc., which have been bonded together to form the nonwoven web. These individually produced layers may differ in terms of production method, basis weight, composition, and fibers.

A nonwoven web material as contemplated by the present invention may also contain an additional fibrous component such that it is considered a composite. For example, a nonwoven web may be entangled with another fibrous component using any of a variety of entanglement techniques known in the art (e.g., hydraulic, air, mechanical, etc.). In one embodiment, a nonwoven web formed from one polymer can be integrally entangled with fibers containing another polymer using hydraulic entanglement. A typical hydraulic entangling process utilizes high pressure jet streams of water to entangle fibers to form a highly entangled consolidated fibrous structure, e.g., a nonwoven web. Hydraulically entangled nonwoven webs are disclosed, for example, in U.S. Patent Nos. 3,494,821 to Evans and 4,144,370 to Boulton, which are incorporated herein in their entirety by reference thereto for all purposes. The fibrous component of the composite may contain any desired amount of the resulting composite. For instance, the fibrous component may contain greater than about 50% by weight of the composite, and in some embodiments, from about 60% to about 90% by weight of the composite. Likewise, the nonwoven web may contain less than about 50% by weight of the composite, and in some embodiments, from about 10% to about 40% by weight of the composite. In some embodiments, the nonwoven web can include a spunbond polyolefin-based web (e.g., polypropylene or polyethylene), while the fibrous component can include fibers containing a blend of polypropylene and VISTAMAXX™ or any other propylene-based plastomer, or a blend of polyethylene and INFUSE™ or any other suitable ethylene-based plastomer.

The nonwoven web material can also be hydroentangled. Hydroentangled nonwoven webs are disclosed, for example, in U.S. Patent No. 7,779,521 to Topolkaraev, et al. With hydroentangling, layer of fibers is deposited on a foraminous support. The foraminous support is commonly a continuous wire screen, sometimes called a forming fabric. Forming fabrics are commonly used in the nonwovens industry and particular types are recognized by those skilled in the art as being advantageous for hydroentangling purposes. Alternatively, the foraminous support may be the surface of a cylinder, and generally may be any surface that supports the fibers and transports them under the water jets or water curtain that impart the energy to entangle the fibers. Innovent Inc. of Peabody, Mass., USA, the aforementioned Rieter Perfojetand, and Fleissner sell screens and cylinders suitable for this purpose. Typically the foraminous support has holes to allow water drainage, but alternatively or additionally the foraminous support may have elevations or grooves, to allow drainage and impart topographic features on the finished fabric. In this context "water" indicates a fluid that is predominantly water, but may contain intentional or unintentional additives, including minerals, surfactants, defoamers, and various processing aides.

When the fibers are deposited on the support they may be completely unbonded, alternatively the fibers may be lightly bonded in the form of a nonwoven when they are deposited on the foraminous support. In other aspects of this invention, unbonded fibers may be deposited on the support and prior to hydroentangling the fibers may be lightly bonded using heat or other means. It is generally desirable that the fibers passing under the water jets have sufficient motility to efficiently hydroentangle.

The general conditions of hydroentangling, i.e., water pressure, nozzle-type, design of the foraminous support, are well known to those skilled in the art. "Hydroentangle" and its derivatives refer to a process for forming a fabric by mechanically wrapping and knotting fibers into a web through the use of a high-velocity jets or curtains of water. The resulting hydroentangled fabric is sometimes called "spunlaced" or "hydroknit" in the literature.

Generally, a high pressure water system delivers water to nozzles or orifices from which high velocity water is expelled. The layer of fibers is transported on the foraminous support member through at least one high velocity water jet or curtain. Alternatively, more than one waterjet or curtain may be used. The direct impact of the water on the fibers causes the fibers to wind and twist and entangle around nearby fibers. Additionally, some of the water may rebound off the foraminous support member, this rebounding water also contributes to entanglement. The water used for hydroentangling is then drained into a manifold, typically from beneath the support member, and generally recirculated. As a result of the hydroentangling process, the fibers are converted into a coherent fabric.

Regardless of the type of nonwoven web material formed, the basis weight of the nonwoven web material may generally vary, such as from about 10 grams per square meter (“gsm”) to about 150 gsm, in some embodiments from about 20 gsm to about 125 gsm, and in some embodiments, from about 25 gsm to about 100 gsm. When multiple nonwoven web materials are used, such materials may have the same or different basis weights.

Furthermore, the present disclosure also generally includes a method of forming a base sheet according to the present disclosure. For instance, referring to Fig. 3, a nonwoven web 202, formed according to any method known in the art using the above discussed materials or the like may be unwound from a first roll 204. The nonwoven web 202 can undergo various processes as known in the art, including embossing (not shown) and has an adhesive 206 applied thereto. As shown in Fig. 3, the present disclosure has found that the adhesive may be applied in-line using a flexographic printer 208. However, it should be understood that, in some aspects, other application methods may be used. Nonetheless, the nonwoven web 202 having the adhesive 206 applied thereto, enters an electroplating apparatus 210 containing staple fibers treated with a cation. As known in the art, the electroplating module 210 contains an electrode, and an electrolyte, causing the plurality of staple fibers to be plated or deposited onto the anion containing adhesive 206. Finally, in one aspect, the nonwoven web 202 containing the electroplated fibers 210 may be calandered 212 to further improve fiber adhesion before being wound on roll 214 as a base sheet according to the present disclosure.

Once the meltblown nonwoven web material, the spunbond nonwoven web material, or any other nonwoven web material is formed, and either prior to or after undergoing electroplating and/or calandering, the nonwoven web material can be further processed to reduce lint left behind when the nonwoven web material is used, to minimize the amount of residue or streaks present on a surface after the surface is contacted with the nonwoven web material, and to enhance the dust holding capacity of the nonwoven web material.

For instance, as discussed above, the nonwoven web material can be apertured, postbonded, or both. Aperturing can enhance the dust holding capacity of the nonwoven web material by creating pockets in the nonwoven web material in which particulates, dust, pathogens, etc. can be trapped. Aperturing can occur by any suitable method known to one having ordinary skill in the art, such as laser aperturing, slit aperturing, pin aperturing, or thermal aperturing using a patterned roll. Meanwhile post-bonding can reduce the amount of lint produced by the nonwoven web material and can also enhance the dust holding capacity of the nonwoven web material by creating indentations in the nonwoven web material in which particulates, dust, pathogens, etc. can be trapped. Although not required, the processes to form apertures and bonds in the nonwoven web material can occur concurrently. However, it should be understood that other methods of forming the apertures and bonds that are not concurrent can also be utilized, as is known to those having ordinary skill in the art. To concurrently form apertures and textured elements on the nonwoven web material, a patterned bonding technique (e.g., thermal point bonding, ultrasonic bonding, etc.) is generally used in which the nonwoven web material is supplied to a nip defined by at least one patterned roll. Thermal point bonding, for instance, typically employs a nip formed between two rolls, at least one of which is patterned. Ultrasonic bonding, on the other hand, typically employs a nip formed between a sonic horn and a patterned roll. Regardless of the technique chosen, the patterned roll contains a plurality of raised bonding elements to concurrently bond the nonwoven web material and form apertures in the nonwoven web material. The size of the bonding elements may be specifically tailored to facilitate the formation of apertures in the nonwoven web material and enhance bonding between the fibers contained in the nonwoven web material. For example, the length dimension of the bonding elements may be from about 300 to about 5000 micrometers, in some embodiments from about 500 to about 4000 micrometers, and in some embodiments, from about 1000 to about 2000 micrometers. The width dimension of the bonding elements may likewise range from about 20 to about 500 micrometers, in some embodiments from about 40 to about 200 micrometers, and in some embodiments, from about 50 to about 150 micrometers. In addition, the "element aspect ratio” (the ratio of the length of an element to its width) may range from about 2 to about 100, in some embodiments from about 4 to about 50, and in some embodiments, from about 5 to about 20.

Besides the size of the bonding elements, the overall bonding pattern may also be selectively controlled to achieve the desired aperture formation. In one embodiment, for example, a bonding pattern is selected in which the longitudinal axis (longest dimension along a center line of the element) of one or more of the bonding elements is skewed relative to the machine direction (“MD”) of the nonwoven web material. For example, one or more of the bonding elements may be oriented from about 30° to about 150°, in some embodiments from about 45° to about 135°, and in some embodiments, from about 60° to about 120° relative to the machine direction of the nonwoven web material. In this manner, the bonding elements will present a relatively large surface to the nonwoven web material in a direction substantially perpendicular to that which the nonwoven web material moves. This increases the area over which shear stress is imparted to the nonwoven web material and, in turn, facilitates aperture formation.

The pattern of the bonding elements is generally selected so that the nonwoven web material has a total bond area of less than about 50% (as determined by conventional optical microscopic methods), in some embodiments, less than about 40%, and in some embodiments, less than about 25%. The bond density is also typically greater than about 50 bonds per square inch, and in some embodiments, from about 75 to about 500 pin bonds per square inch. One suitable bonding pattern for use in the present invention is known as an "S-weave” pattern and is described in U.S. Patent No. 5,964,742 to McCormack, et al., which is incorporated herein in its entirety by reference thereto for all purposes. S-weave patterns typically have a bonding element density of from about 50 to about 500 bonding elements per square inch, and in some embodiments, from about 75 to about 150 bonding elements per square inch. An example of a suitable "S-weave” pattern in shown in Fig. 9, which illustrates S-shaped bonding elements 88 having a length dimension “L” and a width dimension “W.” Another suitable bonding pattern is known as the "rib-knit” pattern and is described in U.S. Patent No. 5,620,779 to Levy, et al., which is incorporated herein in its entirety by reference thereto for all purposes. Rib-knit patterns typically have a bonding element density of from about 150 to about 400 bonding elements per square inch, and in some embodiments, from about 200 to about 300 bonding elements per square inch. An example of a suitable "rib-knit” pattern in shown in Fig. 10, which illustrates bonding elements 89 and bonding elements 91 , which are oriented in a different direction. Yet another suitable pattern is the "wire weave” pattern, which has a bonding element density of from about 200 to about 500 bonding elements per square inch, and in some embodiments, from about 250 to about 350 bonding elements per square inch. An example of a suitable "wire-weave” pattern in shown in Fig. 11 , which illustrates bonding elements 93 and bonding elements 95, which are oriented in a different direction. Other bond patterns that may be used in the present invention are described in U.S. Patent Nos. 3,855,046 to Hansen et al.; 5,962,112 to Haynes et al.; 6,093,665 to Sayovitz et al.; 0375,844 to Edwards, et al.; 0428,267 to Romano et al.; and 0390,708 to Brown, which are incorporated herein in their entirety by reference thereto for all purposes.

The selection of an appropriate bonding temperature (e.g., the temperature of a heated roll) will help melt and/soften nonwoven web material at regions adjacent to the bonding elements. The softened nonwoven web material may then flow and become displaced during bonding, such as by pressure exerted by the bonding elements.

To achieve such concurrent aperture and bond formation without substantially softening the polymer(s) of the nonwoven web material, the bonding temperature and pressure may be selectively controlled. For example, one or more rolls may be heated to a surface temperature of from about 50°C to about 160°C, in some embodiments from about 60°C to about 140°C, and in some embodiments, from about 70°C to about 120°C. Likewise, the pressure exerted by rolls ("nip pressure”) during thermal bonding may range from about 75 to about 600 pounds per linear inch (about 1339 to about 10,715 kilograms per meter), in some embodiments from about 100 to about 400 pounds per linear inch (about 1786 to about 7143 kilograms per meter), and in some embodiments, from about 120 to about 200 pounds per linear inch (about 2143 to about 3572 kilograms per meter). Of course, the residence time of the materials may influence the particular bonding parameters employed.

Another factor that influences concurrent aperture and bond formation is the degree of tension in the nonwoven web material. An increase in nonwoven web material tension when it is passed over the bonding elements, for example, typically correlates to an increase in aperture size. Of course, a tension that is too high may adversely affect the integrity of the nonwoven web material, which could negatively impact the ability to form a cloth with sufficient tackiness and minimal lint production. Thus, in most embodiments of the present invention, a stretch ratio of about 1 .5 or more, in some embodiments from about 2.5 to about 7.0, and in some embodiments, from about 3.0 to about 5.5, is employed to achieve the desired degree of tension in the film during lamination. The stretch ratio may be determined by dividing the final length of the film by its original length.

Generally, the size and/or pattern of the resulting apertures in the nonwoven web material correspond to the size and/or pattern of the bonding elements discussed above. That is, the apertures may have a length, width, aspect ratio, and orientation as described above. For example, the length dimension of the apertures may be from about 200 to about 5000 micrometers, in some embodiments from about 350 to about 4000 micrometers, and in some embodiments, from about 500 to about 2500 micrometers. The width dimension of the apertures may likewise range from about 20 to about 500 micrometers, in some embodiments from about 40 to about 200 micrometers, and in some embodiments, from about 50 to about 150 micrometers. In addition, the "aspect ratio” (the ratio of the length of an aperture to its width) may range from about 2 to about 100, in some embodiments from about 4 to about 50, and in some embodiments, from about 5 to about 20. Similarly, the longitudinal axis of one or more of the apertures (longest dimension along a center line of the aperture) may be skewed relative to the machine direction of the nonwoven web material, such as from about 30° to about 150°, in some embodiments from about 45° to about 135°, and in some embodiments, from about 60° to about 120° relative to the machine direction of the nonwoven web material.

Furthermore, certain aspects of the present disclosure may be better understood according to the following examples, which are intended to be non-limiting and exemplary in nature.

Examples:

Cup Crush: The softness of a nonwoven fabric may be measured according to the "cup crush" test. The cup crush test evaluates fabric stiffness by measuring the peak load (also called the "cup crush load" or just "cup crush") required for a 4.5 cm diameter hemispherically shaped foot to crush a 23 cm by 23 cm piece of fabric shaped into an approximately 6.5 cm diameter by 6.5 cm tall inverted cup while the cup shaped fabric is surrounded by an approximately 6.5 cm diameter cylinder to maintain a uniform deformation of the cup shaped fabric. An average of 10 readings is used. The foot and the cup are aligned to avoid contact between the cup walls and the foot which could affect the readings. The peak load is measured while the foot is descending at a rate of about 0.25 inches per second (380 mm per minute) and is measured in grams. The cup crush test also yields a value for the total energy required to crush a sample (the "cup crush energy") which is the energy from the start of the test to the peak load point, i.e. the area under the curve formed by the load in grams on one axis and the distance the foot travels in millimeters on the other. Cup crush energy is therefore reported in gm-mm. Lower cup crush values indicate a softer laminate. A suitable device for measuring cup crush is a model FTD-G-500 load cell (500 gram range) available from the Schaevitz Company, Pennsauken, N.J. Example 1

A spunbond/spunbond nonwoven web having a basis weight of about 23 gsm and barrier properties was formed. A water-based adhesive treated with an anionic agent supplied by Agatex was applied by flexographic printing to the nonwoven web at a thickness of 100 micrometers. Polyethylene staple fibers having a denier of about 1 .5 and having a length of 500 micrometers treated with a cation supplied by Agatex were adhered to the nonwoven web using an electroplating apparatus described above, forming a base sheet. The base sheet exhibited improved softness while maintaining good barrier properties. For instance, after attachment of the staple fibers, the base sheet exhibited a bacterial filtration efficiency of 98.2% as measured according to UNE-EN 14683:2019 annex B, a breathability of 14.1 Pa/cm2 as measured according to UNE-EN 14683:2019 annex C, and a splash resistance of less than 10.6 kPa as measured according to ISO 22609:2004 ASTM F1862.

Example 2

A polypropylene nonwoven web coformed with pulp fibers was prepared having a basis weight of about 82 gsm. A water-based adhesive treated with an anionic agent supplied by Agatex was applied to the nonwoven web via flexographic printing at a thickness of 100 micrometers. Polyethylene staple fibers having a denier of about 1 .5 and having a length of 500 micrometers were treated with a cation supplied by Agatex, and adhered to the nonwoven web using an electroplating apparatus described above, forming a 150 gsm base sheet with 15% improvement in abrasion as compared to the same nonwoven web without the plurality of staple fibers.

These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various aspects may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.