Apertured hydroentangled nonwovens and methods for making same

Abstract

A method of forming an apertured hydroentangled nonwoven web comprising the steps of forming a nonwoven batt comprising continuous spunmelt fibers, calender bonding the nonwoven batt to form a fully bonded precursor nonwoven web having a regular bond pattern defining individual bond impressions and unbonded areas between the individual bond impressions, the regular bond pattern having a bond area percentage of 10% to 25%, and hydroentifying the fully bonded precursor nonwoven web with a plurality of apertures, the step of hydroentifying comprising hydroprocessing the fully bonded precursor nonwoven web with a plurality of water jet steps as the fully bonded nonwoven web passes a plurality of bars.

Description

[0001] Related Applications

[0002] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 183,190, filed May 3, 2021, entitled “APERTURED HYDRO-PATTERNED NONWOVEN AND METHOD OF MAKING THE SAME,” the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0003] The present invention relates to apertured nonwovens and improved methods of making apertured nonwovens, wherein the nonwovens are imparted with a bond pattern prior to being subjected to hydroentanglement. BACKGROUND

[0005] Melt-spun nonwovens (e.g., spunbond nonwovens, meltblown nonwovens, or combinations thereof) are formed from thermoplastic continuous fibers such as polypropylene (PP), polyethylene terephthalate (PET), and the like, bicomponent or multicomponent fibers, and blends of such melt-spun fibers with rayon, cotton, and cellulose pulp fibers, and the like. Typically, melt-spun nonwovens are produced with bonds that are substantially non-friable and retain their properties through post-bonding processing and conversion by thermal bonding, ultrasonic bonding, chemical (e.g., through latex) bonding, or resin bonding, and the like. Thermal bonding and ultrasonic bonding produce permanent fusions, while chemical bonding can or can not produce permanent bonds.

[0006] It is known to apply hydroentanglement to improve fabric properties, such as softness or loft. One known method of hydroentanglement, referred to as hydroengorgement, is described in, for example, U.S. Patent No. 7,858,544. It is also known to form apertures in nonwoven webs through a number of methods using different technical processes. Such methods include applying heat (e.g., overbonding, heat needles or heat pins, and the like) or using different types of screens (e.g., by pushing the fabric into openings or around rods / protrusions) as described in, for example, U.S. Patent Nos. 7,455,800; 7,091,140; 6,321,425; 6,903,034; and 4,886,632. Aperture patterns formed by hydroentanglement are typically formed in the underlying bonded fabric through a plurality of water jetting steps, each passing through a respective screen having a predetermined pattern of holes, as described in, for example, U.S. Patent No. 10,737,459. For melt-spun fabrics, calendar bonding is used to provide most of the fabric mechanical properties, with subsequent hydroentanglement used to possibly enhance softness and provide apertures.

[0007] However, the need for lower levels of bonding limits the final fabric stability and tensile strength. Past work using hydroentangling techniques to open the apertures on higher bonded fabrics did not produce satisfactory results in terms of aperture definition and therefore it was difficult to use this technique to achieve the desired level of fabric quality such as softness and strength.

[0008] Therefore, there is a need for a method of producing an apertured nonwoven fabric from a fully bonded precursor web that results in a product that exhibits an improved combination of properties such as aperture definition, softness, abrasion resistance, or tensile strength. SUMMARY

[0009] The method of forming an apertured hydro- patterned nonwoven web according to an example embodiment of the present invention includes: forming a nonwoven batt comprising continuous meltspun fibers; calender bonding the nonwoven batt to form a fully bonded precursor nonwoven web having a regular bond pattern defining individual bond impressions and unbonded areas between the individual bond impressions, the regular bond pattern having a bond area percentage of 10% to 25%; and hydro-imbuing the fully bonded precursor nonwoven web with a plurality of apertures, the hydro-imbuing step including hydro- treating the fully bonded precursor nonwoven web by a plurality of water jet steps as the fully bonded nonwoven web passes over a plurality of bars.

[0010] The method of forming an apertured hydro- patterned nonwoven web according to an example embodiment of the present invention includes: forming a nonwoven batt comprising continuous meltspun fibers; calender bonding the nonwoven batt to form a fully bonded precursor nonwoven web having a regular bond pattern defining individual bond impressions and unbonded areas between the individual bond impressions, the regular bond pattern having a bond area percentage of 10% to 25%; and hydro-imbuing the fully bonded precursor nonwoven web with a plurality of apertures, the hydro-imbuing step including hydro- treating the fully bonded precursor nonwoven web by a plurality of water jet steps as the fully bonded nonwoven web passes over a plurality of bars.

[0011] In an example embodiment, each of the bars has a bottom and a top, wherein the area of the bottom is greater than the area of the top.

[0012] In an example embodiment, each bar is symmetrical with respect to a longitudinal axis of the bar.

[0013] In an example embodiment, each bar has a bottom, and the distance between the centers of immediately adjacent bars is at least 100% of the diameter of the bottom, preferably 150% of the diameter of the bottom.

[0014] In exemplary embodiments, the height of the rod is at least 100% of the thickness of the apertured nonwoven web, preferably at least 115% of the thickness of the apertured nonwoven web, more preferably at least 130% of the thickness of the apertured nonwoven web.

[0015] In exemplary embodiments, the height of the rod is at least 200% of the thickness of the precursor web, preferably at least 250% of the thickness of the precursor web, more preferably at least 300% of the thickness of the precursor web.

[0016] In exemplary embodiments, the rod is disposed on a surface moving at substantially the same speed as the calendered bonded precursor nonwoven web.

[0017] In exemplary embodiments, the rods vary in size and / or shape and are disposed on a screen or belt and the distance between the centers of directly adjacent rods is at least 100% of the diameter of the base of the largest of the rods, preferably at least 150% of the diameter of the base of the largest of the rods.

[0018] In exemplary embodiments, the step of forming the precursor web includes the meltspun fibers of the nonwoven batt consisting of spunbond filaments.

[0019] In exemplary embodiments, the step of forming the precursor web includes the nonwoven batt comprising two or more layers.

[0020] In exemplary embodiments, the step of forming the precursor web includes the meltspun fibers in each of the two or more layers comprising spunbond filaments.

[0021] In exemplary embodiments, the step of forming the precursor web includes an average fiber thickness difference between the layers of less than 20%, preferably less than 15%, more preferably less than 10%, even more preferably less than 5%.

[0022] In exemplary embodiments, the step of forming the precursor web includes at least one of the two or more layers comprising spunbond filaments and at least one other of the two or more layers comprising meltblown fibers.

[0023] In exemplary embodiments, the step of forming the precursor web includes at least one layer comprising spunbond filaments forming at least one outer layer of the nonwoven batt.

[0024] In exemplary embodiments, the step of forming the precursor web includes the nonwoven batt comprising three or more layers and the three or more layers forming a spunbond-meltblown-spunbond (SMS) structure.

[0025] In an exemplary embodiment, the method further comprises the step of applying at least one layer formed from fibers and / or particles to the fully bonded nonwoven precursor web prior to the hydroentangling step.

[0026] In an exemplary embodiment, the fibers are short synthetic fibers, preferably based on polyester or viscose.

[0027] In an exemplary embodiment, the fibers are natural fibers, preferably cotton fibers or pulp or modified cellulose such as rayon.

[0028] In an exemplary embodiment, the step of forming the precursor web comprises: the continuous melt-spun fibers are monocomponent fibers formed from a thermoplastic polymer, preferably a homopolymer, a polymer blend based on polyolefin or polyester or polyamide.

[0029] In an exemplary embodiment, the step of forming the precursor web comprises: the continuous melt-spun fibers are multicomponent fibers, preferably bicomponent fibers, and wherein each component is formed from a copolymer of a thermoplastic polymer, preferably a homopolymer, a polymer blend based on polyolefin or polyester or polyamide.

[0030] In an exemplary embodiment, at least 40% of the surface of each filament, preferably at least 50% of the surface of each filament, more preferably at least 60% of the surface of each filament, even more preferably the entire surface of each filament, is covered by a component polymer composition having a lower melting temperature compared to the melting temperature of at least one other component polymer, preferably the difference is at least 2°C, more preferably the difference is at least 5°C.

[0031] In an exemplary embodiment, the step of forming the precursor comprises: the continuous melt-spun fibers comprise a polyolefin or polyamide or polyester or polysaccharide homopolymer, copolymer or polymer blend.

[0032] In an exemplary embodiment, the step of forming the precursor web comprises: the continuous melt-spun fibers comprise polypropylene, polyethylene, polylactic acid, polyhydroxyalkanoate, polyhydroxybutyrate, polybutylene succinate, polyethylene terephthalate, thermoplastic starch, copolymers thereof, copolymers thereof with olefins, esters, amides or other polymers, or blends thereof.

[0033] In an exemplary embodiment, the step of forming the precursor web comprises: the continuous melt-spun fibers are bicomponent core-sheath fibers having a core comprising polypropylene and a sheath comprising a blend of polypropylene and polypropylene-polyethylene copolymer.

[0034] In an exemplary embodiment, the step of forming the precursor web comprises: the continuous melt-spun fibers comprise an additive.

[0035] In example embodiments, the additive comprises an additive selected from the group consisting of: a colorant pigment, a softness enhancer, a slip agent, a filler, and combinations thereof.

[0036] In example embodiments, the step of forming the precursor web comprises forming a bond impression having a bond shape.

[0037] In example embodiments, the bond impression has a first size, and the bond impression is formed by a bond point or nub having a second size, wherein the second size is less than the first size.

[0038] In example embodiments, the bond shape is oriented such that a line intersecting a perimeter of the bond shape having a maximum measurable length along the perimeter of the bond shape and intersecting an axis lying along a surface in a machine direction forms an angle aT of 0 degrees to 65 degrees.

[0039] In example embodiments, the bond shape comprises a convex portion.

[0040] In example embodiments, the bond shape comprises a concave portion.

[0041] In example embodiments, the bond shape comprises at least one of a convex portion and a concave portion.

[0042] In example embodiments, the bond shape is asymmetric.

[0043] In example embodiments, the step of forming the precursor web comprises forming a bond impression in a quilting pattern.

[0044] In example embodiments, the bond impression has a bond shape, and the bond shape is elliptical.

[0045] In example embodiments, the bond impression has a bond shape, and the bond shape is a line.

[0046] In example embodiments, the bond impression has a bond shape, the bond shape having a bond shape perimeter, the bond shape perimeter having a maximum measurable length and a maximum measurable width.

[0047] In example embodiments, an aspect ratio of the maximum measurable length to the maximum measurable width is at least 1.0, preferably at least 1.5, more preferably at least 2.0, even more preferably at least 2.5.

[0048] In example embodiments, the fully bonded nonwoven precursor web includes at least 20 bond impressions per square centimeter, preferably at least 40 bond impressions per square centimeter, more preferably at least 50 bond impressions per square centimeter, and even more preferably at least 60 bond impressions per square centimeter.

[0049] In example embodiments, the bond impression line intersects the bond shape perimeter having the greatest measurable length along the bond shape perimeter and intersects an axis lying on the surface along the machine direction to form an angle aT of 20 degrees to 80 degrees, preferably 40 degrees to 80 degrees, and even more preferably 50 degrees to 70 degrees.

[0050] In example embodiments, the step of forming the precursor web includes forming the fully bonded nonwoven precursor web with less than 20 bond impressions per square centimeter, preferably less than 15 bond impressions per square centimeter, more preferably less than 5 bond impressions per square centimeter.

[0051] In example embodiments, the bond impression has a bond shape having a bond shape perimeter having a greatest measurable length and a greatest measurable width, and an aspect ratio of the greatest measurable length to the greatest measurable width is at least 2.0, more preferably at least 2.5, and even more preferably at least 3.

[0052] In example embodiments, the bond shape is a line.

[0053] In example embodiments, the bond shape is an S-shape.

[0054] In example embodiments, the bond impression has a bond shape having a bond shape perimeter having a greatest measurable length and a greatest measurable width, and a bond impression line intersects the bond shape perimeter having the greatest measurable length along the bond shape perimeter and intersects an axis lying on the surface along the machine direction to form an angle aT of 5 degrees to 15 degrees, preferably 8 degrees to 12 degrees, and even more preferably 9 degrees to 11 degrees.

[0055] In example embodiments, the step of forming the precursor web includes forming bond impressions in a quilt pattern.

[0056] In example embodiments, the bond impressions of the quilt pattern have a quilt pattern line intersecting an imaginary line extending along the machine direction to form an angle aT of 5 degrees to 60 degrees, preferably 10 degrees to 50 degrees, and even more preferably 15 degrees to 40 degrees.

[0057] In example embodiments, the precursor nonwoven web has an MD HOM value of at least 5 g.

[0058] In an exemplary embodiment, the precursor nonwoven web has a CD HOM value of at least 2 g.

[0059] In an exemplary embodiment, the precursor nonwoven web has a MD HOM value of 30 g or less, preferably 25 g or less.

[0060] In an exemplary embodiment, the precursor nonwoven web has a CD HOM value of 20 g or less, preferably 15 g or less.

[0061] In an exemplary embodiment, the precursor nonwoven web has a basis weight of at least 5 gsm, preferably at least 10 gsm, preferably at least 15 gsm, more preferably 20 gsm or less.

[0062] In an exemplary embodiment, the precursor nonwoven web has a basis weight of 60 gsm or less, preferably 50 gsm or less, more preferably 45 gsm or less, even more preferably 35 gsm or less.

[0063] In an exemplary embodiment, the step of hydroentangling comprises applying water pressure to the nonwoven precursor web with water jets.

[0064] In an exemplary embodiment, the water pressure applied to the precursor web represents an energy flux of at least 0.2 kWh / kg, preferably at least 0.3 kWh / kg.

[0065] In an exemplary embodiment, the water pressure applied to the precursor web represents an energy flux of 1.9 kWh / kg or less, preferably 3.0 kWh / kg or less.

[0066] In an exemplary embodiment, the step of hydroentangling comprises applying water pressure to the nonwoven precursor web with at least two groups of water jets.

[0067] In an exemplary embodiment, the method is carried out at a line speed of at least 150 m / min.

[0068] In an exemplary embodiment, the line speed is 450 m / min or less.

[0069] In an exemplary embodiment, the step of hydroentangling comprises applying water pressure to the nonwoven precursor web with four groups of water jets, each water jet applying a pressure of 150 bar or more.

[0070] In an exemplary embodiment, the step of hydroentangling comprises applying water pressure to the nonwoven precursor web with three groups of water jets, each group of water jets applying a pressure greater than the pressure applied by the group of water jets preceding said group of water jets in the machine direction.

[0071] In example embodiments, the three groups of water jets include a first group of water jets, a second group of water jets preceding the first group of water jets in the machine direction, and a third group of water jets preceding the first and second groups of water jets in the machine direction, the second group of water jets applying a pressure that is 80% to 95% of the pressure applied by the first group of water jets, and the third group of water jets applying a pressure that is 64% to 90% of the pressure applied by the second group of water jets.

[0072] In example embodiments, the step of hydroentangling includes applying water pressure to the nonwoven precursor web by three groups of water jets, each water jet applying a pressure of 200 bar or greater.

[0073] In example embodiments, the step of hydroentangling includes applying water pressure to the nonwoven precursor web by two groups of water jets, each water jet applying a pressure of 300 bar or greater.

[0074] In example embodiments, the step of hydroentangling includes applying a water jet to the calender bonded precursor nonwoven web at an angle of 80° to 100° relative to the calender bonded precursor nonwoven web.

[0075] In example embodiments, the step of hydro-empowering the fully bonded precursor nonwoven web with a plurality of apertures includes at least partially altering the individual bond impressions by applying water pressure.

[0076] In example embodiments, the step of at least partially altering results in at least 60% of the fully bonded portion of the individual bond impressions remaining after the step of hydro-empowering.

[0077] In example embodiments, the step of at least partially altering results in at least 70% of the fully bonded portion of the individual bond impressions remaining after the step of hydro-empowering.

[0078] In example embodiments, the step of at least partially altering results in at least 80% of the fully bonded portion of the individual bond impressions remaining after the step of hydro-empowering.

[0079] In example embodiments, the step of at least partially altering results in at least 90% of the fully bonded portion of the individual bond impressions remaining after the step of hydro-empowering.

[0080] In example embodiments, the step of at least partially altering results in dividing the individual bond impressions into at least two portions.

[0081] In exemplary embodiments, the step of at least partially altering results in fibers in the area around the perimeter of the respective bond impression randomly wearing into and out of the major plane of the fully bonded precursor nonwoven web so as to at least partially eliminate the three-dimensionality of the respective bond impression.

[0082] According to exemplary embodiments, the apertured hydroentangled nonwoven web is produced according to any of the preceding process steps.

[0083] In exemplary embodiments, the apertured hydroentangled nonwoven web has a basis weight of 60 gsm or less, preferably 50 gsm or less, more preferably 45 gsm or less, even more preferably 35 gsm or less.

[0084] In exemplary embodiments, the apertured hydroentangled nonwoven web has a MD tensile strength of at least 4 N / cm.

[0085] In exemplary embodiments, the apertured hydroentangled nonwoven web has a CD tensile strength of at least 2 N / cm.

[0086] In exemplary embodiments, the apertured hydroentangled nonwoven web has a thickness (caliper) of at least 12 microns / gsm of fabric.

[0087] In exemplary embodiments, the apertured hydroentangled nonwoven web does not exhibit two-sidedness.

[0088] In exemplary embodiments, the apertured hydroentangled nonwoven web does not exhibit visual two-sidedness when observed by the naked eye.

[0089] In exemplary embodiments, the apertured hydroentangled nonwoven web does not exhibit two-sidedness in terms of abrasion rating.

[0090] In exemplary embodiments, the apertured hydroentangled nonwoven web does not exhibit two-sidedness in terms of coefficient of friction.

[0091] In exemplary embodiments, the apertured hydroentangled nonwoven web has a visible aperture definition of at least 3 on a scale of 1 to 5.

[0092] The method of forming apertured hydro- patterned nonwoven web according to exemplary embodiments of the present application comprises: providing a fully bonded precursor nonwoven web having a regular bond pattern defining individual bond impressions and unbonded areas between the individual bond impressions, the regular bond pattern having a bond area percentage of 10% to 25%; and hydro- treating the fully bonded precursor nonwoven web by a plurality of water jetting steps as the fully bonded nonwoven web passes a plurality of bars so as to form a plurality of apertures in the fully bonded precursor nonwoven web. BRIEF DESCRIPTION OF DRAWINGS

[0093] The above and related objects, features and advantages of the present application will be more fully understood by reference to the following detailed description of the presently preferred, albeit illustrative, embodiments of the present application, when taken in conjunction with the accompanying drawings, in which:

[0094] FIG. 1 is a representative diagram of a system for forming a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0095] FIG. 2A is a representative diagram of a system for forming a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0096] FIG. 2B is a representative diagram of a system for forming a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0097] FIG. 3 is a diagram showing various dimensions of a bar according to exemplary embodiments of the present application;

[0098] FIG. 4 is a diagram showing various dimensions of a bond impression according to exemplary embodiments of the present application;

[0099] FIG. 5 is a diagram showing various dimensions of a bond impression according to exemplary embodiments of the present application;

[0100] FIG. 6 shows a bond pattern that can be used in a method for forming a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0101] FIG. 7 shows a bond pattern that can be used in a method for forming a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0102] FIG. 8 shows a bond pattern that can be used in a method for forming a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0103] FIG. 9 Bond pattern showing a method that can be used to form a patterned hydro- apertured nonwoven web according to exemplary embodiments of the present application;

[0104] FIG. 10 Macro and magnified view of two sides of a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0105] FIG. 11 Photograph showing a plan view of a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0106] FIG. 12 Photograph showing a plan view of a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0107] FIG. 13 Macro and magnified view of two sides of a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0108] FIG. 14 Macro and magnified view of two sides of a patterned hydro-apertured nonwoven web according to exemplary embodiments of the present application;

[0109] FIG. 15 Magnified view of two sides of a conventional apertured nonwoven web;

[0110] FIG. 16 Aperture definition visual grading scale according to exemplary embodiments of the present application;

[0111] FIG. 17 Perspective view of a grading scale for pile evaluation in the Martindale Average Abrasion Resistance Rating Test;

[0112] FIG. 18 Martindale Abrasion Test Method Grading Scale;

[0113] FIG. 19A to FIG. 19D Cross-sectional variations of individual bond impressions produced by the method of exemplary embodiments of the present application are shown;

[0114] FIG. 19E and FIG. 19F Microphotograph showing cross-sectional variations of individual bond impressions produced by a conventional hydroentanglement process;

[0115] FIG. 20A to FIG. 20C Photograph showing a plan view of a patterned hydro-apertured nonwoven web prepared according to Example 8 described herein;

[0116] FIG. 21A to FIG. 21Cis a photograph showing a plan view of a patterned hydro- apertured nonwoven web prepared according to Example 9 described herein;

[0117] FIG. 22A and FIG. 22B illustrate plan views of a patterned nonwoven web before and after hydroprocessing according to example embodiments of the present application; and

[0118] FIG. 23A and FIG. 23B illustrate plan views of a patterned nonwoven web before and after hydroprocessing according to example embodiments of the present application. DETAILED DESCRIPTION

[0119] The present application relates to improved techniques for hydroprocessing nonwoven fabrics and imparting apertures to nonwoven fabrics and to nonwoven fabrics manufactured using these methods.

[0120] The hydroprocessed and / or nonwoven webs formed with a pattern of apertures according to the present application can be suitable for use in disposable absorbent articles. As used herein, the term "absorbent article" refers to articles that absorb and contain fluids and solid materials. For example, absorbent articles can be placed against or near the body to absorb and contain various exudates discharged from the body. Absorbent articles can be articles that are worn, such as baby diapers, adult incontinence products, and feminine care products, or sanitary products for absorbing fluids and solid materials, such as for use in medical professionals using products such as disposable gowns and clamps. In particular, the nonwovens according to example embodiments of the present application can be used as or as part of a body contacting layer (e.g., a topsheet) of an absorbent article, or for forming other components of an absorbent article, such as a backsheet, a waistband, or a fastening tab. The nonwovens according to example embodiments of the present application can also be used to package or enclose articles such as absorbent articles. The term "disposable" is used herein to describe absorbent articles that are not intended to be washed or otherwise restored or reused as absorbent articles, but rather are intended to be discarded after a single use and preferably are recyclable, compostable, or otherwise disposed of in an environmentally compatible manner after a single use.

[0121] The term "fluff" as used herein refers to the fibrous material prior to being bonded to one another. The "fluff" includes individual fibers that are generally not bonded to one another, although some amount of pre-bonding between the fibers can occur, and such pre-bonding can occur, for example, during or shortly after laying down of the fibers in a melt spinning process. However, such pre-bonding still allows for a substantial amount of the fibers to move freely so that they can be repositioned. The "fluff" can include several layers, which are created by depositing fibers from several spinners in a melt spinning process, and the distribution of fiber diameters and porosity in the "sub-layers" laid down from the various heads are not significantly different. Adjacent layers of fibers need not be separated from one another by sharp changes, and the various layers can be partially intermixed in areas around the boundaries.

[0122] The terms "fiber" and "filament" are used interchangeably herein (e.g., "endless filaments" or "staple fibers" and the like) unless otherwise indicated.

[0123] The term "nonwoven, nonwoven fabric, sheet or web" as used herein refers to a sheet or web of randomly or regularly oriented fibers or filaments that are first formed into a fluff, and then one or more fluffs are laid on top of one another and consolidated and bonded together by friction, cohesion, adhesion or one or more bonding patterns and by localized compression and / or application of pressure, heat, ultrasonic, or thermal energy, or combinations thereof. The term does not include fabrics that are woven, knitted or stitch-bonded with yarns or filaments. The fibers can be natural or man-made and can be staple or continuous filaments or formed in situ. Commercially available fibers have diameters ranging from about 0.0005 mm to about 0.25 mm, and they come in several different forms: short fibers (known as staple or cut fibers), continuous single fibers (filaments or monofilaments), untwisted bundles of continuous filaments (tow) and twisted bundles of continuous filaments (yarn). Nonwoven fabrics can be formed by a number of processes including, but not limited to, meltblowing, spunbonding, meltspinning, solvent spinning, electrospinning, carding, film fibrillation, melt film fibrillation, air laying, dry-laying, wet laying with staple fibers and combinations of these processes as known in the art. The basis weight of nonwoven fabrics is often expressed in grams per square meter (gsm).

[0124] The term "meltspun fiber" refers to a fiber formed by heating a thermoplastic polymer (e.g., polypropylene, polyester, or nylon) and extruding it through a metal plate having hundreds of holes in it, called a spinneret or die. Examples of meltspun fibers include spunbond fibers and meltblown fibers. Meltspun fibers can be monocomponent, formed from a single polymer component or a single blend of polymer components, or can be multicomponent, where the cross-section of each fiber includes at least two discrete polymer components or blends of polymer components, or at least one discrete blend of polymer components and at least one discrete blend of polymer components. Fibers having two discrete components can be referred to as bicomponent fibers.

[0125] A web or fabric made with meltspun fibers can be referred to as a "meltspun web or fabric."

[0126] The term "spunbond fiber" as used herein means substantially continuous fibers or filaments having an average diameter of 10-30 micrometers. Also included are splitable bicomponent or multicomponent fibers having an average diameter of 5-30 micrometers prior to splitting.

[0127] The term "meltblown fiber" as used herein means substantially continuous fibers or filaments having an average diameter of less than 10 micrometers.

[0128] "Filament diameter" or "fiber diameter" or "fiber thickness" is measured in units of pm. The terms "filament diameter," "fiber diameter," and "fiber thickness" can be used interchangeably. The term "grams per 9000 m of filament" (also denier or den) or "grams per 10000 m of filament" (dTex) is used to express the fineness or coarseness of a filament because it relates to the filament diameter (assuming a circular filament cross-section) multiplied by the density of the material used.

[0129] The term "fully bonded nonwoven" as used herein and understood by those skilled in the art means a nonwoven having fibers that have been fused to one another under a bond impression via melting and solidification. Such fabrics can be used as is for various applications, for example, turned into a diaper or the like, or as a precursor for further processing, for example, hydrophilic spin finish applications or hydroentanglement. For example, a fully calender bonded nonwoven can be produced by passing a batt under pressure through the nip between two heated rolls, thereby providing a pattern of fused embossed impressions in the fabric. The pressure and temperature within the nip are sufficient to soften and melt the individual fibers, which are then fused together using a pattern of protrusions on at least one of the heated rolls to create a series of fused impressions in which the majority of the fibers within the fused impressions cannot be distinguished as individual fibers. The bond impressions result in fusing of the fibers, or in the case of bicomponent fibers, fusing of at least one component having the lowest melting temperature through the entire thickness of the fabric. The roll temperature and pressure are adjusted depending on the fabric formulation and basis weight. For example, 100% polypropylene copolymer spunbond at 20-25 gsm is typically bonded at a roll temperature of > 150°C and a nip pressure of greater than 90 N / mm. The temperature / pressure settings are adjusted to handle different basis weights and / or line speeds. Higher basis weights and / or line speeds can require increased nip pressure and / or temperature to obtain a "fully" bonded fabric with fused bond points. It should be understood that for the purposes of the present disclosure, adhesive bonding is not within the definition of "fully bonded".

[0130] The term "bond area percentage" as used herein means the ratio of the area occupied by bond impressions to the total surface of the nonwoven fabric, expressed as a percentage and measured according to the Bond Area Percentage method described herein.

[0131] With respect to the manufacture of nonwoven web materials and the nonwoven web materials themselves, the "cross direction" (CD) refers to the direction along the web material that is substantially perpendicular to the direction of forward travel of the web material through a production line that manufactures the web material. With respect to a batt of nonwoven web material moving through the nip of a pair of calender rolls to form a bonded nonwoven web, the cross direction is perpendicular to the direction of movement through the nip and parallel to the nip.

[0132] With respect to the manufacture of nonwoven web materials and the nonwoven web materials themselves, the "machine direction" (MD) refers to the direction along the web material that is substantially parallel to the direction of forward travel of the web material through a production line that manufactures the web material. With respect to a nonwoven batt of nonwoven web material moving through the nip of a pair of calender rolls to form a bonded nonwoven web, the machine direction is parallel to the direction of movement through the nip and perpendicular to the nip.

[0133] A "bonding protrusion" or "protrusion" is a feature of a bonding roll that is surrounded by a recessed area at its radially outermost portion. A bonding protrusion contains a radially outermost bonding surface having a bonding surface shape and a bonding surface shape area that generally lays along an outer cylindrical surface having a substantially constant radius from the bonding roll axis of rotation; however, a protrusion having a discrete and separate shaped bonding surface generally has a radius from the bonding roll that is small enough so that the bonding surface can appear to be flat / planar; and the bonding surface shape area approximates a planar area of the same shape. A bonding protrusion can have sides that are perpendicular to the bonding surface, although generally the sides have angled bevels so that the cross-section of the base of the bonding protrusion is larger than its bonding surface. A plurality of bonding protrusions can be arranged in a pattern on a calender roll. A plurality of bonding protrusions have a bonding area per unit surface area of the outer cylindrical surface that can be expressed as a percentage, and the percentage of the outer cylindrical surface per unit surface area is the ratio of the sum of the bonding shape areas of the protrusions within a cell to the total surface area of the cell.

[0134] A "bonding impression" or "fused bonding impression" in a nonwoven web is a structure of the nonwoven web resulting from the impression of a bonding protrusion on a calender roll. A bonding impression is a location of deformed, intermeshed or entangled, and melted or heat fused material from fibers that are stacked and compressed in the z-direction under a bonding protrusion, which forms a bond or bonding area. Individual bonds can be connected in a nonwoven structure by loose fibers between them. The shape and size of a bonding impression generally corresponds to the shape and size of the bonding surface of a bonding protrusion on a calender roll. For purposes of this disclosure, "bonding impression thickness" is understood to mean the width of a bonding impression area in the plane of the nonwoven web. One or both of the rolls can have its peripheral surface machined, etched, engraved, or otherwise formed to have a bonding pattern of bonding protrusions and recessed areas thereon so that the bonding pressure exerted on the batt at the nip is concentrated at the bonding surfaces of the bonding protrusions and is reduced or substantially eliminated at the recessed areas. The bonding surfaces have a bonding surface shape. Thus, an impression pattern of bonds is formed on the nonwoven web between the fibers that form the web that has bonding impressions and bonding shapes corresponding to the pattern and bonding surface shapes of the bonding protrusions on the roll. A repeating pattern of bonding protrusions and recessed areas can be formed on a bonding roll. The bonding shapes delineate the raised surfaces of the bonding protrusions on the roll, while the areas between them represent the recessed areas. During the calender bonding (or calendering) process, the bonding shapes of the bonding protrusions press similarly shaped bonding impressions onto the web.

[0135] FIG. 1 is a block diagram showing various components used in a process for making an apertured nonwoven web according to an exemplary embodiment of the present invention. Although FIG. 1The illustrated method produces a nonwoven web having an SMS structure (2; 3; 4), it being understood that the method can be reconfigured to form many other web structures including one or more spunbond layers and / or one or more meltblown layers, for example, fabrics having a single or multiple spunbond layers, more specific examples being S, SS, SSS, etc.; fabrics having a combination of spunbond and meltblown layers, typically having a spunbond layer forming at least one outer surface of the fabric, more specific asymmetric combinations being SSMS, SMSSMMS, SMMMSS, etc. fabrics or symmetric examples being SMS, SMMS, SMMMS, SSMSS, etc. fabrics; fabrics combining meltspun layers with other layers, more specific examples being a combination of a meltspun layer formed from endless filaments with staple fibers formed from natural materials, etc. The nonwoven web structures are not limited to the examples provided herein, and one of ordinary skill in the art will understand that many other such structures can be obtained by varying the number and arrangement of process components.

[0136] Generally, it is to be understood that the number and configuration of the dies are not limited to the number and configuration illustrated and described herein, and in other example embodiments the number and configuration of the dies can be varied to achieve different web structures. For example, a single spunbond die can be used to form a nonwoven batt 6 on a conveyor 8 having a single spunbond layer, or multiple spunbond dies can be used to form a batt 6 having a multiple spunbond layer structure, for example, SS, SSS, SSSS, etc. The layers formed by the multiple dies can be the same as or very similar to one another in terms of filament type, process parameters, etc., such that the layers are essentially indistinguishable from one another, thereby forming something that appears to be a single layer structure, or they can be produced differently from one another, thereby forming a nonwoven product that is distinctly layered.

[0137] In another example embodiment, only spunbond dies 2 and meltblown dies 3 are used to form a nonwoven batt 6 on a conveyor 8. According to another example embodiment of the present application, multiple elements corresponding to the dies 2, 3 can be incorporated in a system to form a batt 6 having multiple corresponding layers, for example, SM, SMM, SSM, SSMM, etc. Again, the layers formed by the multiple dies, typically the same type of dies, can be the same as or very similar to one another in terms of filament type, process parameters, etc., such that the layers are essentially indistinguishable from one another, thereby forming something that appears to be a single layer structure, or they can be produced differently from one another, thereby forming a nonwoven product that is distinctly layered.

[0138] According to exemplary embodiments of the present application, the melt-spun nonwoven batt 6 is made from continuous filaments laid in a random distribution on a moving conveyor belt 8. Resin pellets can be processed into a melt under heat and then fed through a spinneret (or spinning dies 2 and 4) to produce hundreds of filaments by use of a stretching device (not shown). Multiple spinnerets or dies (blocks in series) can be used to provide increased density of spunbond fibers corresponding to, for example, each of the spinning dies 2 and 4. A jet of fluid (e.g., air) causes the fibers from the dies 2 and 4 to be elongated and then the fibers are blown or carried onto a moving web (conveyor belt) 8 where they are laid flat and drawn in a random pattern against the web 8 by suction boxes (not shown) to form the batt 6. A meltblown layer can be deposited by a meltblown mechanism (or "die") 3 preferably between spunbond layers laid by the spinning dies 2 and 4. The meltblown ("MB") layer can be formed by a meltblown process, but can also be formed by various other known processes. For example, the meltblown process involves inserting a thermoplastic polymer into a die. The thermoplastic polymer material is extruded through a plurality of fine capillaries in the die to form fibers. The stream of molten thermoplastic polymer material is attenuated by a high velocity gas (e.g., air) stream to reduce their diameters, which can be microfiber diameters. The meltblown fibers are deposited quasi-randomly by the die 3 onto the moving web or moving web having spunbond layers laid by the spinning dies 2 to form a meltblown layer. One, two or more meltblown blocks can be used in series to increase the coverage of fibers. The meltblown fibers can be tacky when deposited, which often results in some bonding between the meltblown fibers of the web.

[0139] In preferred embodiments, the fibers used to form the batt 6 are thermoplastic polymers, examples of which include polyolefins (e.g., polypropylene "PP" or polyethylene "PE"), polyesters (e.g., polylactic acid "PLA" or polyhydroxyalkanoate "PHA" or polyhydroxybutyrate "PHB" or polybutylene succinate "PBS" or polyethylene terephthalate "PET" and the like), polyamides, polysaccharides thereof (e.g., thermoplastic starch "TPS" or starch-based polymers and the like), copolymers thereof (with olefins, esters, amides or other monomers), and blends thereof. Preferably, the fibers are made from polyolefins, examples of which include polyethylene, polypropylene, propylene-butylene copolymers thereof, and blends thereof, including, for example, ethylene / propylene copolymers and polyethylene / polypropylene blends. Resins with higher crystallinity and lower elongation at break can also be suitable due to the likelihood of easier breakage. The fibers can also be formed from, for example, non-oil based components, such as aliphatic polyesters, thermoplastic polysaccharides or other biopolymers, or they can contain such substances as additives or modifiers. As used herein, the term "blend" includes a uniform or semi-uniform mixture of at least two polymers.

[0140] Another method involves forming a nonwoven web of multi-component or preferably "bicomponent" polymer fibers. Such bicomponent polymer fibers can be formed through a spinneret having two adjacent sections representing a first component from one polymer or blend and a second component from another to form a fiber having a cross-section with the first component in one section and the second component in the other section (hence the term "bicomponent"). The components can be advantageously selected to have different melting temperatures and / or expansion-contraction rates. These different properties of the two polymers, when combined in a side-by-side or asymmetric sheath-core geometry, can result in the bicomponent fiber product crimping as they cool and are pulled from the spinneret during spinning. The resulting crimped fibers can then be laid in a batt and calender bonded in a pattern. The crimp in the fibers is believed to increase the loft and pile of the web, enhancing the visual and tactile softness signals.

[0141] Other formulation variations can also be employed, such as the addition of CaCO3, to provide a more readily broken and / or permanently deformed spunbond fiber and thus provide improved aperturing. Those skilled in the art will appreciate many other formulation variations, e.g., color additives, processing additives, filament surface modifiers, such as softness enhancers, etc., depending on further requirements for end fabric performance or specific meltspun thread requirements.

[0142] In one exemplary embodiment, the batt 6 can be heat calender bonded via the rollers 10 and 12. One or both rollers 10 and 12 can have a circumferential surface that is machined, etched, engraved, or otherwise formed to have a pattern of protrusions and recessed areas thereon such that the bonding pressure exerted on the batt 6 at the nip is concentrated at the outward facing surfaces of the protrusions and is reduced or substantially eliminated at the recessed areas. In accordance with an exemplary embodiment of the present application, the roller 10 is a calender roller and the roller 12 is a bonding roller that defines a bonding pattern. The heat calender bonding produces a fully bonded precursor web 7. Preferred bonding patterns in accordance with an exemplary embodiment of the present application are further described below.

[0143] In accordance with an exemplary embodiment of the present application, the precursor nonwoven web 7 is then hydroentangled using a plurality of water jet sprayers 16a, 16b, and 16c. FIG. 1Each of the elements 16a, 16b, and 16c shown may represent a group of multiple jets in a corresponding predetermined arrangement. According to an exemplary embodiment of the invention, as the precursor nonwoven web 7 is conveyed below the jets 16a to 16c via the belt 22, the high-pressure water jets of the jets 16a, 16b, and 16c act on and pass through the fabric. In an exemplary embodiment, the belt 22 includes a bar pattern for imparting holes to the precursor nonwoven web 7. According to an exemplary embodiment of the invention, the bars have a bottom, and the distance between the centers of directly adjacent bars is at least 100% of the bottom diameter, and in a preferred embodiment, 150% of the bottom diameter.

[0144] The corresponding dewatering systems 20a, 20b, and 20c can be positioned below each ejector (group) 16a to 16c to draw water away and dry the precursor fabric 7. The dewatering systems 20a, 20b, and 20c may include, for example, a vacuum chamber, a suction chamber, a Uhle chamber, a fan, and / or a vacuum trough. The nonwoven precursor web 7 can then be dried by blowing hot air over the web, via an IR dryer, or other drying techniques (e.g., air drying).

[0145] According to an exemplary embodiment of the invention, band 22 may be combined with one or more screens (not shown), each screen having a predetermined pattern for supporting the precursor nonwoven web 7, while being hydraulically treated by corresponding water jets 16a to 16c. See below for reference. FIG. 2A and FIG. 2B In further detail, one or more screens may be replaced by one or more rollers 14, with one roller or the last roller in a series of rollers having a sleeve 18. The screen or sleeve may include a bar pattern for imparting apertures to the precursor nonwoven web 7. According to an exemplary embodiment of the invention, fewer than three sets of jets 16a to 16c may be used to hydraulically treat and / or impart apertures to the precursor nonwoven web 7.

[0146] According to exemplary embodiments of the present application, one or more cylinders are used, where one cylinder or the last cylinder in a series of cylinders has a sleeve with a pattern of bars, and each cylinder is also associated with one or more water jets, resulting in multiple water jetting steps. The required water pressure at each step depends on multiple parameters, including the number of water jetting steps and the line speed. Generally, the more water jetting steps used in the process, the less pressure is required at each step to obtain the desired fabric properties. In other words, the energy flux obtained with multiple water jets (each water jet applying an amount of water pressure) can also be obtained by increasing the number of water jets and decreasing the amount of water pressure applied by each jet. The water pressure required in each step also depends at least in part on the line speed. Higher line speeds require higher pressure to maintain a constant flux. In other words, the energy flux obtained using line speed and jet pressure can also be obtained by decreasing the line speed and the jet pressure.

[0147] Without being bound by theory, it is believed that the preferred total water jet pressure applied to the precursor web 7 can be expressed in terms of energy flux. According to exemplary embodiments, the preferred energy flux applied to the precursor web 7 is at least 0.2 kWh / kg, preferably at least 0.3 kWh / kg, preferably at least 0.5 kWh / kg, preferably from 0.2 to 3.0 kWh / kg, preferably from 0.3 to 1.9 kWh / kg, and also preferably from 0.5 to 1.9 kWh / kg. The required energy flux can be obtained by, for example, changing the machine speed and / or the water pressure at each water jet. Preferably, the required energy flux is achieved by using one or more water jets at a relatively lower pressure rather than using fewer water jets at a higher pressure. The energy flux can be calculated using the following formula:

[0148] Flux = ((J1.5)*(G2)*(I)*(L / 1000)*(7 / 10000000000)) / F, where:

[0149]

[0150] J = water pressure, bar

[0151] g = jet orifice diameter, microns

[0152] I = orifices per meter of jet

[0153] L = nonwoven width, m

[0154] F = nonwoven mass flow (i.e., production of nonwoven web, calculated based on line speed, product width, and basis weight), kg / hr

[0155] In exemplary embodiments using a series of rollers, the rod on the last roller on the process line provides the entire aperturing of the precursor web 7. In this regard, the rollers prior to the last roller in the production line are preferably not provided with a rod, but rather can be provided with a mesh screen. In exemplary embodiments, the second to last roller in a row of rollers can be provided with a rod to prepare the precursor fabric for aperturing, but the actual opening / aperturing of the precursor web 7 is preferably performed at the last roller. It should be understood that in other exemplary embodiments of the present application, the rods can be provided on the belt rather than on the rollers.

[0156] Preferred exemplary embodiments of the present application involve the use of a relatively large number of water jets. Without being bound by theory, the use of a larger number of jets allows for a higher line speed without having to increase the jet pressure. It should be noted that for the purposes of the present disclosure, two or more water jets having the same settings, particularly with respect to the number and geometry of the water jets and the water pressure, are considered to be a single water jet.

[0157] In exemplary embodiments, the plurality of water jetting steps can include exposing the fully calender bonded polyolefin-based nonwoven precursor web 7 to a plurality of water jets, each water jet applying a pressure of 180 bar, preferably 200 bar or greater. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, for a more specific example, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0158] In exemplary embodiments, the plurality of water jetting steps can include exposing the fully calender bonded polyolefin-based nonwoven precursor web 7 to two water jets, each water jet applying a pressure of 250 bar, preferably 300 bar or greater. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, for a more specific example, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0159] In exemplary embodiments, the plurality of water jetting steps can include exposing the fully calender bonded polyolefin-based nonwoven precursor web 7 to at least four water jets, each water jet applying a pressure of 150 bar or greater. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, for a more specific example, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0160] In exemplary embodiments, the plurality of water jetting steps can include exposing the fully calender bonded, polyester-based nonwoven precursor web 7 to at least three water jets, each water jet applying a pressure of 60 bar, preferably 75 bar or higher. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm, and a line speed of 150 to 450 meters / minute, in a more particular embodiment, the precursor web has a basis weight of 25 gsm, and a line speed of 200 meters / minute.

[0161] In exemplary embodiments, the plurality of water jetting steps includes exposing the fully calender bonded nonwoven precursor web 7 to three water jets (where each water jet has a set of jets / nozzles), where each water jet applies a higher pressure in the machine direction than the immediately preceding water jet. For example, water jet 16c can apply a higher pressure than water jet 16b, and water jet 16b can apply a higher pressure than water jet 16a. In particular exemplary embodiments, the amount of pressure applied by water jet 16b is at least 80%, preferably 80% to 95%, of the pressure applied by water jet 16c, and the amount of pressure applied by water jet 16a is at least 80%, preferably 80% to 95%, of the pressure applied by water jet 16b. In embodiments, the amount of pressure applied by water jet 16a is at least 64%, preferably 64% to 90%, of the pressure applied by water jet 16c. The relatively low pressure applied by water jet 16a results in initial softening of the precursor web without opening the apertures, the higher pressure applied by water jet 16b prepares the precursor web for aperturing by beginning to change the individual bond impressions (as explained in further detail below), and the final water jet 16c, which applies the highest amount of pressure in the machine direction, creates apertures in the precursor web and further changes the individual bond impressions. Without being bound by theory, it is believed that the rising gradient of applied pressure helps to preserve the individual bond impressions during the softening and preparation stages of the process, and allows for controlled changes to the individual bond impressions and aperture creation in the final stage.

[0162] In embodiments, the plurality of water jetting steps includes exposing the fully calender bonded nonwoven precursor web 7 to two water jets (where each water jet has a set of jets / nozzles), where each water jet applies a higher pressure in the machine direction than the immediately preceding water jet. For example, water jet 16c can apply a higher pressure than water jet 16b, and water jet 16a can be excluded.

[0163] In embodiments, the plurality of water jetting steps includes exposing the fully calender bonded nonwoven precursor web 7 to four or more water jets (where each water jet has a set of jets / nozzles), where each water jet applies a higher pressure in the machine direction than the immediately preceding water jet.

[0164] In exemplary embodiments, the step of hydro-impregnating the plurality of apertures of the fully bonded precursor nonwoven web comprises at least partially altering each bond impression by applying water pressure. In this regard, applying water pressure can result in at least some of the fully bonded portions of each bond impression being removed, such that at least 60%, preferably at least 70%, more preferably 80%, and even more preferably 90% of the fully bonded portions of each bond impression remain after the hydro-impregnation step.

[0165] In embodiments, applying water pressure can result in each bond impression being divided into at least two portions. In embodiments, applying water pressure can result in a reduction in the overall size of each bond impression while maintaining the overall profile of each bond impression. For example, as shown in FIG. 20A to FIG. 20C , FIG. 22A and FIG. 22B in the case of an elliptical bond impression (e.g., Pattern 1), the alteration can result in a reduction in the size of the elliptical shape while maintaining the overall elliptical profile of the bond impression. As other examples, as shown in FIG. 21A to FIG. 21C , FIG. 23A and FIG. 23B in the case of an S-shaped bond impression having a bond area in the shape of a relatively narrow line forming an S-shape (e.g., Pattern 3), the alteration can result in the S-shaped line being divided into several portions. Without being bound by theory, it is believed that the at least partial alteration of each bond impression results in an improvement in tactile softness and does not significantly reduce the tensile strength and / or abrasion resistance of the final product. Tactile softness is a complex value that is difficult to express by simple measurements because it represents the sensation provided by a human finger. The values measured in this application (thickness, HOM, COF) are partial measurements of tactile softness and their values do not represent tactile softness in their complexity.

[0166] In embodiments, as shown in FIG. 19A to FIG. 19F applying water pressure results in fibers in the area around the perimeter of each bond impression randomly grinding into and out of the major plane of the fully bonded precursor nonwoven web so as to at least partially remove the naturally reinforced fibers around the perimeter of each bond impression, thereby at least partially eliminating the three-dimensionality of each bond impression. More specifically, FIG. 19A is a cross-sectional view showing the formation of a single bond impression with a patterned calender roll 12 and a smooth calender 10 with naturally reinforced fibers at the edge of the bond impression, FIG. 19B is a cross-sectional view of a bonded precursor web having a single bond impression 100 and naturally reinforced fibers at the edge of the bond impression, and FIG. 19C is a cross-sectional view showing a hydro-processed nonwoven web having an altered single bond impression with no naturally reinforced fibers at the edge of the bond impression and the bond impression itself slightly smaller. FIG. 19Dis a microphotograph of a cross-section of a single bonded impression according to an exemplary embodiment of the present application showing how hydroprocessing causes an abraded edge around the bonded impression, with no naturally reinforced fibers around the perimeter of the bonded impression. In contrast, FIG. 19E and FIG. 19F is a microphotograph of a cross-section of a conventional precursor bonded impression as shown in U.S. Patent No. 8,410,007, where naturally reinforced fibers are clearly visible.

[0167] Without being bound by theory, it is believed that the randomization of fibers around the perimeter of each bonded impression results in a softer final product (tactile softness).

[0168] FIG. 2A and 2B shows an exemplary embodiment of the present application employing one or more cylinders for imparting apertures in the nonwoven fabric. Like elements are marked with the same reference numerals as in FIG. 1 and a repeated detailed description of these elements is omitted here.

[0169] As FIG. 2A shown, spunbond die 2, meltblown die 3, and spunbond die 4 can be used to form batt 6 on conveyor belt 8. Batt 6 can then be bonded with calender rolls 10 and 12 to form fully bonded precursor nonwoven 7. Likewise, according to other exemplary embodiments of the present application, multiple elements corresponding to each of dies 2, 3, 4 can be incorporated in the system to form a SM or SMS type of fabric by, for example, depositing multiple meltblown layers, thereby forming batt 6 having multiple corresponding layers. It should be understood that the number, type, and arrangement of dies is not limited to those described and shown herein, and it should be understood that any other combination of meltblown, spunbond, and / or meltblown / spunbond web structures can be formed according to exemplary embodiments of the present application by varying the number, type, and / or arrangement of dies.

[0170] According to exemplary embodiments of the present application, apertures are hydro- imparted to the nonwoven precursor web 7 by passing web 7 around cylinder 14 as one or more water jets 16 apply pressurized water to web 7. According to exemplary embodiments of the present application, cylinder 14 can be covered with sleeve 18, which can be made of metal or plastic, and which has a predetermined pattern of bars that form apertures in precursor fabric / web 7 under the influence of the water pressure applied by water jets 16. According to exemplary embodiments of the present application, the bars have a base, and the distance between the centers of the bars is at least 100% of the base diameter, preferably at least 150% of the base diameter, more preferably at least 200% of the base diameter. For the purposes of this measurement, as FIG. 3As shown, the bottom is used to indicate the portion of the rod before it begins to flare outward to contact the flat portion of the sleeve. Where the bottom of the rod is not circular, the "diameter" is considered to refer to the shortest dimension passing through the bottom of the rod (e.g., if the rod is elliptical, the "diameter" would be the length of the minor axis of the ellipse).

[0171] The precursor nonwoven web 7 is wound around the roller 14, and as it passes beneath the jets 16, the high-pressure water jets of the jets 16 act on and penetrate the fabric to deform it according to the bar pattern on the sleeve 18. A dewatering system 20 can be positioned below each jet 16 to draw water away from or through the holes, thereby creating holes in the precursor fabric (web 7) corresponding to the bar pattern on the sleeve 18 beneath the fabric 7. The perforated nonwoven web 9 can then be dried by blowing hot air through the web, by using an IR dryer or other drying techniques (e.g., air drying).

[0172] According to an exemplary embodiment of the invention, the height of the bar is at least 100% of the thickness of the perforated nonwoven web, preferably at least 115% of the thickness of the perforated nonwoven web, and more preferably at least 130% of the thickness of the perforated nonwoven web, wherein the thickness of the perforated nonwoven web is measured on the final dried product. For the purposes of this disclosure, the height of the bar is considered to refer to the height measured from the bottom to the top of the bar as described above.

[0173] According to an exemplary embodiment of the invention, the height of the rod is at least 150% of the precursor thickness, preferably at least 200% of the precursor web thickness, more preferably at least 250% of the precursor web thickness, and more preferably at least 300% of the precursor web thickness, wherein the thickness of the precursor nonwoven web is measured on the dried precursor before entering the water treatment process.

[0174] like FIG. 2A As shown, at least one, preferably multiple, waterjet nozzles (jeters 16) can be used to make openings on a roller 14 so that subsequent rollers do not damage the clarity of the opening pattern.

[0175] According to an exemplary embodiment of the present invention, using FIG. 2Aa single cylinder 14 with sleeves having patterns provided with rods, wherein the single cylinder 14 is associated with one or more water jets, resulting in multiple water jetting steps. The required water pressure at each step depends on the number of water jetting steps. According to exemplary embodiments, the preferred energy flux applied to the precursor web 7 is 0.2 to 3.0 kWh / kg, preferably 0.3 to 1.9 kWh / kg. The required energy flux can be obtained by, for example, varying the machine speed and / or the water pressure at each water jet. Preferably, the required energy flux is achieved by using one or more water jetting stations at a relatively low pressure instead of fewer water jetting stations at a higher jet pressure.

[0176] In exemplary embodiments, the multiple water jetting steps can include exposing the fully calender bonded nonwoven precursor web 7 to three sets of water jets, each water jet applying a pressure of 200 bar or greater, as the web 7 travels around the single cylinder 14. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, in more particular embodiments, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0177] In exemplary embodiments, the multiple water jetting steps can include exposing the fully calender bonded nonwoven precursor web 7 to two sets of water jets, each water jet applying a pressure of 250 bar or greater, as the web 7 travels around the single cylinder 14. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, in more particular embodiments, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0178] In exemplary embodiments, the multiple water jetting steps can include exposing the fully calender bonded nonwoven precursor web 7 to at least four sets of water jets, each water jet applying a pressure of 150 bar or greater, as the web 7 travels around the single cylinder 14. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, in more particular embodiments, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0179] FIG. 2B A system for imparting apertures to a nonwoven web using more than one cylinder according to exemplary embodiments of the present application is shown. As FIG. 2BAs shown, spunbond die 2 and meltblown die 3 can be used to form a wadding 6 on conveyor belt 8. The wadding 6 can then be bonded using calendering rollers 10 and 12 to form a fully bonded precursor nonwoven web 7. Similarly, according to another exemplary embodiment of the invention, multiple elements corresponding to each of dies 2, 3, and 4 can be incorporated into the system, for example, by depositing multiple meltblown layers to form SMMS or SMMMS fabrics to form a wadding 6 with multiple corresponding layers. Likewise, it should be understood that the number, type, and arrangement of dies are not limited to those described and shown herein, and it should be understood that any other combination of meltblown, spunbond, and / or meltblown / spunbond web structures can be formed by varying the number, type, and / or arrangement of dies according to exemplary embodiments of the invention.

[0180] like FIG. 2B As shown, the method according to this exemplary embodiment includes using two rollers, a first roller 14a and a second roller 14b, wherein the second roller 14b follows the processing line after the first roller 14a. It should be understood that the number of rollers is not limited to two, and any number of rollers can be used. According to an exemplary embodiment of the invention, when one or more water jets 16b apply pressurized water to the web 7, perforation hydraulics are imparted to the nonwoven precursor web 7 by causing the web 7 to bypass the roller 14b (the last roller of two rollers in a row). According to an exemplary embodiment of the invention, the roller 14b may be covered by a sleeve 18, which may be made of metal or plastic and has a predetermined pattern of bars forming perforations in the precursor fabric / web 7. According to an exemplary embodiment of the invention, the bars have bottoms, and the distance between the centers of the bars is at least 100% of the bottom diameter, preferably at least 150% of the bottom diameter, and more preferably at least 200% of the bottom diameter.

[0181] The precursor fabric 7 is wound around rollers 14a and 14b, and as the fabric 7 passes beneath the ejector 16b associated with the second roller 14b, a high-pressure water jet from the ejector 16b acts on and passes through the fabric to deform it according to the bar pattern on the sleeve 18. Water tanks or vacuum tanks / areas 20a, 20b can be positioned below each ejector 16a, 16b to draw water away or through holes, thereby creating holes in the precursor fabric (fabric 7) corresponding to the bar pattern on the sleeve 18 beneath the fabric 7. The perforated nonwoven fabric 9 can then be dried by blowing hot air through the fabric, by an IR dryer, or by other drying techniques such as air drying.

[0182] The entire aperturing is preferably performed at the second (last in the row) cylinder 14b with at least one, preferably multiple water jet dies (sprayers 16b) so that the subsequent cylinders do not destroy the clarity of the aperturing pattern. In this regard, the cylinders prior to the last cylinder in the line (e.g., cylinder 14a) are preferably not provided with rods, but can be provided with a mesh screen. In an exemplary embodiment, the second to last cylinder in the row of cylinders can be provided with rods to prepare the precursor fabric for aperturing, but the actual opening / aperturing of the precursor fabric is preferably performed at the last cylinder.

[0183] According to exemplary embodiments of the present application, only the last cylinder 14b (in the row of cylinders) with a sleeve provided with a rod pattern is used, wherein the cylinder 14b is associated with one or more water sprayers, resulting in multiple water spraying steps. The required water pressure at each step depends on the number of water spraying steps. According to exemplary embodiments, the preferred energy flux applied to the precursor web 7 is 0.2 to 3.0 kWh / kg, preferably 0.3 to 1.9 kWh / kg. The required energy flux can be obtained by, for example, changing the machine speed and / or the water pressure at each water jet. Preferably, the required energy flux is achieved by using one or more water spraying stations at a milder pressure instead of fewer water spraying stations at a higher sprayer pressure.

[0184] In an exemplary embodiment, the multiple water spraying steps can include exposing the fully calender bonded nonwoven precursor web 7 to three water sprayers, each applying a pressure of 300 bar or more, as the web 7 travels around the cylinder 14b. In an exemplary embodiment, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, in a more particular embodiment, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0185] In an exemplary embodiment, the multiple water spraying steps can include exposing the fully calender bonded nonwoven precursor web 7 to two water sprayers, each applying a pressure of 250 bar or more, as the web 7 travels around the cylinder 14b. In an exemplary embodiment, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute, in a more particular embodiment, the precursor has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0186] In exemplary embodiments, the plurality of water jetting steps can include exposing the fully calender bonded nonwoven precursor web 7 to at least four water jets as the web 7 travels around the drum 14b, each water jet applying a pressure of 150 bar or greater. In exemplary embodiments, the precursor web 7 has a basis weight of 15 gsm to 45 gsm and a line speed of 150 to 450 meters / minute. In more particular embodiments, the precursor web has a basis weight of 25 gsm and a line speed of 200 meters / minute.

[0187] Without being bound by theory, it is believed that the precursor nonwoven web properties have a strong influence on the final fabric characteristics. The fully bonded precursor nonwoven web is exposed to hydro patterning as discussed herein, which forces the fibers in the web to shape around the bars on the screen through fiber movement, breakage, and / or inelastic deformation. This shape is retained in the web and thus provides the desired level of definition of the apertures as well as improvements in other attributes such as softness, mechanical stability, etc. Important features of the precursor nonwoven according to exemplary embodiments of the present application are described below.

[0188] In exemplary embodiments, the precursor nonwoven web can have a percent bond area of preferably at least 5%, preferably at least 10%, more preferably 10% to 25%. The "percent bond area" on a nonwoven web refers to the ratio of the area occupied by the bond impressions to the total surface area of the web, expressed as a percentage and measured according to the percent bond area method described herein. The method for measuring percent bond area is described in U.S. Patent No. 8,841,507, the contents of which are incorporated by reference in their entirety herein, and is also described below.

[0189] In exemplary embodiments, the precursor nonwoven web can have a bond pattern made up of a number of bond impressions, each bond impression having a maximum measurable length and a maximum measurable width.

[0190] FIG. 4 A bond pattern on a precursor nonwoven web according to exemplary embodiments of the present application is shown, referred to herein as "Pattern 3"; the bond shape 100 of each bond impression has a maximum measurable length L, which is measured by identifying a shape length line 104 that intersects the perimeter of the shape at an intersection point that is the maximum distance apart that can be identified on the perimeter, i.e., the distance between the two most distant points on the perimeter. As shown, the bond shape 100 has a maximum measurable width W, which is measured by identifying a shape width line 106 that intersects the perimeter of the shape at an intersection point that is the maximum distance apart that can be identified on the width, i.e., the distance between the two most distant points on the width. FIG. 4As shown, the bond shape 100 has a maximum measurable width W, which is measured by identifying a respective shape width line 105a, 105b that is parallel to the shape length line 104 and that is tangent to the shape perimeter at one or more outermost points that are furthest from the shape length line 104 on either side thereof. It will be appreciated that for some shapes (e.g., semicircles), one of the shape width lines 105a, 105b can coincide / collinear with the shape length line 104. The maximum measurable width W is the distance between the shape width lines 105a, 105b.

[0191] Shapes within the scope of the present invention have an aspect ratio of the maximum measurable length L to the maximum measurable width W of at least 1.0, preferably at least 1.5, more preferably at least 2.0, even more preferably at least 2.5. For example, ellipses within an elliptical pattern according to an exemplary embodiment of the present invention (referred to herein as “Pattern 1”) have an aspect ratio of the maximum measurable length L to the maximum measurable width W of 1.8, and straight lines within a straight line pattern (referred to herein as “Pattern 2”) have an aspect ratio of the maximum measurable length L to the maximum measurable width W of 8.5. The bond shapes and dimensions pressed onto the nonwoven web will reflect and correspond to the bond shapes 100 and their dimensions on the calender roll.

[0192] Without wishing to be bound by theory, it is believed that a calender roll bond protrusion having a bond shape with one or more features as described herein has an aerodynamic effect on the airflow in and around the nip of the calender roll, which causes the air in and around the nonwoven fibers to accelerate and decelerate in a manner that repositions the fibers. This repositioning of the fibers can achieve a tear or a loft that is advantageous in forming a hole shape around the rod during the hydrographic patterning process as described herein.

[0193] Additionally, the rotational orientation of the protrusions has an aerodynamic effect. In exemplary embodiments, a pattern having bond impressions spaced apart has bond shapes 100, and the bond protrusions supporting them can be arranged along a shape tilt angle with respect to the machine direction and the cross direction. Without wishing to be bound by theory, it is believed that the shape tilt angle should not exceed a certain amount at which the bond protrusions have a maximum beneficial effect on the airflow. Again referring to FIG. 1, the shape tilt angle is the angle between the bond shape 100 and the machine direction 102. FIG. 4The shape tilt angle aTmay be expressed as the smaller angle formed by the intersection of an axis along the machine direction 108 with the shape length line 104. It is believed that the shape and shape tilt angle have a synergistic effect on air flow. It is believed that the shape tilt angle aTprovides the desired influence on air flow such that it should not exceed 65 degrees, more preferably 40 degrees, still more preferably 30 degrees. It is believed that a shape tilt angle within this range effectively provides air flow through the nip while imparting a lateral vector component to the air flow through the nip. Conversely, a shape tilt angle greater than 50 degrees can create too much resistance to air flow through the nip to have a beneficial effect, and even greater shape tilt angles in combination with a sufficient density of bonding protrusions can have the effect of creating sufficient resistance at the nip to substantially divert air flow from the nip (i.e., toward the side of the bonding roll) rather than through the nip. The bonding shape and rotational orientation imprinted on the nonwoven web will reflect and correspond to the bonding shape and rotational orientation on the roll.

[0194] In other exemplary embodiments of the present application, the bonding impressions form a so-called "quilted seam pattern". For the purposes of this specification, a nonwoven having a quilted seam pattern is a nonwoven having relatively large and regularly spaced un-bonded areas. The un-bonded areas are formed by the intersection of bonding lines that extend from opposite edges of the nonwoven and generally cross the web in a diagonal direction. The bonding lines are spaced apart from one another such that they leave un-bonded areas between the lines. In exemplary embodiments, the surface area of the un-bonded areas is greater than the thickness of the bonding lines as measured on the surface of the web. For example, with reference to FIG. 9 (Pattern 4), which illustrates a quilted seam pattern, the square between the bonding lines has a surface area that is preferably at least 3 times the thickness of the bonding lines, more preferably at least 4 times the thickness of the bonding lines, most preferably at least 5 times the thickness of the bonding lines. The bonding lines can be formed by unbroken lines or individual bonding points arranged in a consistent direction.

[0195] For the quilted seam pattern, without being bound by theory, it is believed that the quilted seam pattern tilt angle aTqprovides the desired influence on air flow such that it should not exceed 60 degrees, more preferably 50 degrees, still more preferably 40 degrees. With reference to FIG. 5 , the pattern tilt angle aTqmay be expressed as the smaller angle formed by the intersection of an axis along the machine direction 108 with the quilted seam pattern line 104q.

[0196] Without being bound by theory, it is believed that less uniform filament direction on a microscale tends to form more stable hole edges in all directions. Conversely, more uniform microscale orientation can tend to form holes with higher density of filaments aligned in a preferred direction on the hole edges. It is believed that for optimal results, it is even more desirable that the quilting pattern tilt angle aTq is from 5 to 15 degrees, more preferably from 8 to 12 degrees, and even more preferably from 9 to 11 degrees. The rotational orientation of the bond pattern imprinted on the nonwoven web will reflect and correspond to the rotational orientation of the bond pattern on the roll.

[0197] Still referring to FIG. 4 , the bond shape 100 can have a shape perimeter with a convexity 102a, 102b on both sides of the shape length line 104. FIG. 4 It is also shown that the convexity can have a varying radius or radii. In other exemplary embodiments, the bond shape 100 can include only a single convexity (e.g., to form a single arc rather than multiple arcs as shown in FIG. 4 It is believed that in keeping with this specification, the bond protrusions having bond surfaces, repeating and arranged in a pattern, have a beneficial effect on the acceleration and deceleration of air through the nonwoven fibers at and around the nip, and have the advantage of forming holes in the fully bonded nonwoven around the rod. Likewise, the bond shape and size imprinted on the nonwoven web will reflect and correspond to the bond shape and size on the roll.

[0198] The shape perimeter can have a convexity on both sides of the shape length line, forming a symmetrical shape, such as a circle, an ellipse, etc. Such a shape can be found in Pattern 1 mentioned herein.

[0199] The shape perimeter can have a convexity on both sides of the shape length line 104, with or without varying radii, such that it has the overall profile of an airfoil with symmetrical curvature in cross-section. In another alternative, the shape perimeter can have a convexity on one side of the shape length line 104, with a straight portion on the shape length line 104 or on the other side of the shape length line 104, such that it has the overall profile of an airfoil / aircraft wing with asymmetrical curvature in cross-section. In another alternative, the shape perimeter can have a convexity and a concavity 103 on one side of the shape length line 104, disposed substantially opposite the concavity, as shown in FIG. 4 Such a shape is found in Pattern 3 referred to herein.

[0200] Table 1 describes bond patterns that can be used in exemplary embodiments of the present invention, but are not limited thereto:

[0201]

[0202]

[0203] Table 1

[0204] The bond-crease patterns 1 to 3 disclosed herein are formed from bond-creases each having a limited area. Such bond-creases are referred to as "discontinuous". The bond-crease pattern 4 has a minimum distance of 0.6 mm between adjacent bond-creases, thus the bond-creases are considered to be one continuous bond-crease (quilt pattern).

[0205] As can be seen from the examples given, bond-creases can have different sizes, and thus bond-patterns can look very different for comparable bond areas. For example, pattern 1 has small bond-creases in close proximity to each other (approximately 50 bond-creases per cm2), whereas, in contrast, pattern 3 provides large bond-creases in the form of S-shaped lines that are relatively far apart from each other (approximately 2.5 bond-creases per cm2). It should be noted that particularly large bond shapes or quilt patterns are preferably formed from one large uniform bond-crease, but can also consist of several smaller bond-creases that form an overall bond shape. For example, the individual S-shapes within pattern 3 can be generated by a number of smaller bond points or dots. For the purposes of the present disclosure, adjacent bond-creases are considered to be one bond-crease when the minimum distance between adjacent bond-creases is less than 0.7 mm, preferably less than 0.5 mm, even more preferably less than 0.4 mm, most preferably less than 0.3 mm.

[0206] In exemplary embodiments, the precursor nonwoven web 7 has at least 20 bond-creases per cm2, preferably at least 30 bond-creases per cm2, more preferably at least 40 bond-creases per cm2, more preferably at least 50 bond-creases per cm2, even more preferably at least 60 bond-creases per cm2. For the purposes of the present specification, a bond-crease having a value of bond-creases per cm2 within these ranges is considered to be a "small" size bond-crease.

[0207] For certain pattern designs, it can not be clear how to determine the number of bond-creases per defined area. This can occur, for example, for patterns having several different types of bond-crease size or shape, or for patterns having un-bonded areas that serve as part of the design. In such cases, a bond-crease is considered to be small when the total area of the bond-creases (fused filament area) is less than 1 mm 2

[0208] ​Without being bound by theory, it is believed that the size and shape of the bond impressions that make up the bond pattern affect the final hydro- patterned fabric properties, such as hole definition, softness, stiffness, and pattern visibility, to name a few examples. For example, where the bond impressions are small in size and much smaller than the holes formed, during the hydro- patterning process, the bond impressions are moved aside by the bar and thus a higher density of bond impressions is formed compared to the precursor web, which in turn increases the stiffness of the apertured fabric product (see FIG. 10 ).

[0209] According to another exemplary embodiment, the bond impressions are large in size and thus can be comparable in size to the holes and in exemplary embodiments, can be larger in size than the holes. Such relatively large bond impressions can provide a relatively small bond impression density for the precursor web, such as less than 20 bond impressions per square centimeter, preferably less than 15 bond impressions per square centimeter, more preferably less than 10 bond impressions per square centimeter, and even more preferably less than 5 bond impressions per square centimeter. For the purposes of this specification, bond impressions having a value of bond impressions per square centimeter within these ranges are considered to be "large" size bond impressions.

[0210] Without being bound by theory, it is believed that the large bond impressions on the precursor web 7 that undergo the above-described hydro-aperturing process can result in a fabric having a high definition hole pattern, where the bond impressions are visible to the naked eye, providing the fabric with a desired and highly visible design of both holes and bond impressions.

[0211] Without being bound by theory, it is believed that the bond impression shape and orientation in the MD / CD direction also affect the hole definition and the integrity of the bond pattern in the hydro-patterned fabric. For example, certain bond pattern shapes can negatively interact with the bar during the hydro- patterning process, resulting in reduced hole definition in the fabric and a damaged bond pattern. Conversely, bond patterns having spaced bond impressions arranged in rows and / or columns and / or having certain shapes can avoid interference with the bar pattern, resulting in high definition holes with visible and intact bond impressions between the holes.

[0212] Without being bound by theory, it is believed that large bond impressions behave differently than small bond impressions during the hydro-patterning process. For example, during the hydro-patterning process, large impressions are not as easily moved aside, such that the bond impression density does not significantly change, if at all, compared to the impression density of the precursor web. For example, as shown in FIG. 11 S-shaped bond impressions of pattern 3 provide space for the bar arranged in a regular "square" bar pattern to form holes and the shape, slant, and aspect ratio of the impressions provide enhanced hole definition and enhanced mechanical properties, such as softness. Also as shown in FIG. 11As shown, the S-shaped bond impressions of pattern 3 are visible to the naked eye in the fabric, due to the fact that the bond impressions are able to "flow" around the rod during the hydro patterning process.

[0213] As another example, FIG. 12 It is shown that the bond impressions of pattern 4 (big dots) are visible in the holes, although not very pronounced compared to pattern 3. In particular, in this example, the precursor web is fully bonded using pattern 4 consisting of big circles and small diamonds very close together. The small diamonds act as small bond impressions and are not clear to the naked eye after the hydro patterning process. In contrast, the big circles of pattern 4 are still visible, thus forming together with the holes a different visual effect than the initial thermal bond pattern on the precursor.

[0214] In an exemplary embodiment, the precursor nonwoven web 7 provides bond impressions of different sizes. For example, WO2017190717 discloses a bond pattern consisting of primary and secondary bond impressions. In this case, the density of the big bond impressions, the small bond impressions should be judged separately. For example, the density of the small (or secondary) bond impressions should be estimated from the area, without considering the big (or primary) bond impressions.

[0215] In an exemplary embodiment, the precursor nonwoven web can have a stiffness represented by the Handle-O-Meter method (HOM). During the test, the fabric is forced to bend into a nip having a relatively small proportion (6.2 mm wide, 8.0 mm deep), which is considered similar to the filament bending around the rod. If the bending force is too small, the filaments act in an elastic manner and thus tend to return to their initial position after the hydro patterning, which in turn leads to at least partial closure of the holes after the hydro patterning. If the bending force is high, the filaments can tend to break and the free ends of the filaments can interfere with the holes, thus reducing the level of clarity of the holes. Furthermore, when the bending force is too high, the fabric resistance can not allow the rod to enter the structure and prevent the formation of the holes.

[0216] According to an exemplary embodiment, the precursor nonwoven web 7 has an MD HOM value of at least 5 g.

[0217] According to an exemplary embodiment, the precursor nonwoven web 7 has an MD HOM value of at most 30 g, preferably at most 25 g.

[0218] In an exemplary embodiment, the precursor nonwoven web 7 has a CD HOM value of at least 2 g.

[0219] According to an exemplary embodiment, the precursor nonwoven web 7 has a CD HOM value of at most 20 g, preferably at most 15 g.

[0220] According to exemplary embodiments, the apertured hydro- patterned nonwoven web 9 has a basis weight of 10 gsm to 45 gsm, preferably 20 gsm to 35 gsm.

[0221] According to exemplary embodiments, the apertured hydro- patterned nonwoven web 9 has a thickness of at least 12 microns / gsm of fabric.

[0222] According to exemplary embodiments, the apertured hydro- patterned nonwoven web 9 has an MD tensile strength of at least 4 N / cm.

[0223] According to exemplary embodiments, the apertured hydro- patterned nonwoven web 9 has a CD tensile strength of at least 2 N / cm.

[0224] According to exemplary embodiments, the apertured hydro- patterned nonwoven web 9 does not exhibit two-sidedness. This can be seen in FIG. 13 and FIG. 14 , FIG. 13 and FIG. 14 macro and magnified photographs of a fabric according to exemplary embodiments of the present application. The apertured hydro-patterned nonwoven web 9 does not exhibit two-sidedness, at least in terms of physical and material properties.

[0225] In contrast, most conventional aperturing techniques result in the formation of three-dimensional or conical holes, which in turn results in the final web product exhibiting two-sidedness. For example, conventional techniques that use heat with a needle / stick typically provide holes that have a less than ideal tactile feel due to the fact that one side of the hole is clearly evident (see FIG. 15 ). The two-sidedness associated with conventional apertured web products can interfere with the performance of such products due to the fact that one side of the fabric exhibits undesirable properties.

[0226] The apertured hydro-patterned nonwoven web 9 according to exemplary embodiments of the present application exhibits a relatively high level of softness. This is due, at least in part, to the lack of sharp edges around the holes. This is in contrast to most conventional techniques that use heat to provide openings in a fabric. It should be noted that softness is itself a very general term that involves many various sensations, some of which can be represented by measurements, such as Handle-O-Meter, cantilever test, compressibility, thickness, coefficient of friction, and / or many other methods. Each test provides only a partially limited information about softness and can be applicable to some applications or some ranges of basis weight, some polymer compositions, etc.

[0227] The nonwoven web 9 can be bonded into a nonwoven laminate. The nonwoven laminate can include additional layers of continuous fibers, such as spunbond fibers and meltblown fibers, and can include composite nonwovens, such as spunbond-meltblown-spunbond laminates. The nonwoven laminate can also include short fibers such as staple fibers or can include pulp fibers. These short fibers can be in the form of a consolidated web, such as a carded web or a tissue sheet, or can be initially unconsolidated. The nonwoven laminate can also include superabsorbent material in particulate form or in fibrous form. The laminate can be formed by conventional means, including but not limited to thermal bonding, ultrasonic bonding, chemical bonding, adhesive bonding, and / or hydroentanglement. According to embodiments of the present application, the web 9 can form a nonwoven laminate resulting from one or more of the above-mentioned processes for use as a topsheet, an absorbent core, or a backsheet of an absorbent article.

[0228] The following examples and comparative examples illustrate the advantages of the present application.

[0229] Comparative Example 1 (precursor web of Example 1)

[0230] A 25 gsm meltspun nonwoven batt was produced in-line from a mixture of polypropylene (type 3155E5 from Exxon) with a color additive (SCC 91056 from Standridge Color Corporation) and a softening enhancer additive based on erucamide (CESA-Slip PP 42161 from Avient) in a continuous process, where monocomponent polypropylene filaments of 13-25 pm diameter were produced and subsequently collected on a moving belt. The batt was produced using REICOFIL 3.1 technology (REICOFIL® by Reicofil GmbH & Co. KG, Troisdorf, Germany), from a single spunbond die. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 3 ) on its surface. The temperature of the calender rolls (smooth roll / embossed roll) was 160°C / 162°C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 2. FIG. 8

[0231] Example 1

[0232] ​The same nonwoven web was formed as described in Comparative Example 1, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last cylinder in the row provided the web with apertures. The first cylinder had a wire screen and two jets at the cylinder, each jet applied the water pressure shown in Table 2. The first cylinder was used to hydro treat the web before aperturing at the second cylinder. Each jet had two rows of holes, the holes in each row were spaced 0.6 mm apart from each other. The second cylinder had a screen with an Al pattern with bars (the bars were spaced 4.5 mm apart from each other) as described herein. Three jets applying water pressure as shown in Table 2 were used to hydro pattern the web with apertured pattern by forcing the web down onto the bars. The three jets at the second cylinder each had two bands of holes, the holes within each band were spaced 0.6 mm apart from each other. The aperturing method of Example 1 is summarized in Table 3. The resulting nonwoven web had the material properties shown in Table 2.

[0233] Comparative Example 2 (precursor web of Example 2)

[0234] A 25 gsm melt-spun nonwoven batt was produced in-line from a mixture of polypropylene (Mosten NB425 from Unipetrol) and copolymer (Vistamaxx 6202 from Exxon) in a weight ratio of 75:15, a colorant additive (SCC 91056 from Standridge Color Corporation), and a softening additive based on erucamide (CESA-slipPP 42161 from Avient) in a continuous process, where monocomponent polypropylene filaments with a fiber diameter of 13-25 pm were produced and subsequently collected on a moving belt. The REICOFIL 3.1 technology was employed, and the batt was produced from four dies. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 3 FIG. 8 ) on its surface. The temperature of the calender rolls (smooth roll / embossed roll) was 150 °C / 155 °C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 2.

[0235] Example 2

[0236] The same nonwoven web was formed as described in Comparative Example 2, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 200 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two rows of holes, the holes within each band spaced 1.2 mm apart from each other. The second cylinder had a screen with the A1 pattern of bars (the bars spaced 4.5 mm apart from each other) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar, respectively, were used to hydro pattern the web with the pattern of apertures by forcing the web down onto the bars. The three jets at the second cylinder each had two bands of holes, the holes within each band spaced 0.6 mm apart from each other. The aperturing method of Example 2 is summarized in Table 3. The resulting nonwoven web had the material properties shown in Table 2.

[0237] Comparative Example 3 (precursor web of Example 3)

[0238] A 25 gsm melt-spun nonwoven batt was produced in-line from a mixture of polypropylene (type 3155E5 from Exxon) with a colorant additive (SCC 91056 from Standridge Color Corporation) in a continuous process, where monocomponent polypropylene filaments with a fiber diameter of 13-25 μιη were produced and subsequently collected on a moving belt. The batt was produced using REICOFIL 3.1 technology from four spunbonding dies. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 2 FIG. 7 The temperature of the calender rolls (smooth roll / embossed roll) was 160°C / 162°C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 2.

[0239] Example 3

[0240] The same nonwoven web was formed as described in Comparative Example 3, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 200 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two bands of holes, each row of holes spaced 1.2 mm apart from each other. The second cylinder had a screen with an Al pattern of bars (the bars spaced 4.5 mm apart from each other) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar, respectively, were used to hydro pattern the web with the pattern of apertures by forcing the web down onto the bars. The three jets at the second cylinder each had two bands of holes, the holes within each band spaced 0.6 mm apart from each other. The aperturing method of Example 3 is summarized in Table 3. The resulting nonwoven web had the material properties shown in Table 2.

[0241] Comparative Example 4 (precursor web of Example 4)

[0242] A 25 gsm melt-spun nonwoven batt was produced in-line from a mixture of polypropylene (Mosten NB425 from Unipetrol) and copolymer (Vistamaxx 6102 from Exxon) in a weight ratio of 75:15, a colorant additive (SCC 91056 from Standridge Color Corporation), and a softening additive based on erucamide (CESA-slipPP 42161 from Avient) in a continuous process, where monocomponent polypropylene filaments with a fiber diameter of 13-25 pm were produced and subsequently collected on a moving belt. The REICOFIL 3.1 technology was employed to produce the batt from the die. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 2 FIG. 7 ) applied to the surface of the roll. The temperature of the calender rolls (smooth roll / embossed roll) was 150 °C / 155 °C, and the pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 2.

[0243] Example 4

[0244] The same nonwoven web was formed as described in Comparative Example 4, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 200 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two bands of holes, the holes in each band spaced 1.2 mm apart from each other. The second cylinder had a screen with the A1 pattern of bars (the bars spaced 4.5 mm apart from each other) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar, respectively, were used to hydro pattern the web with the pattern of apertures by forcing the web down onto the bars. The three jets at the second cylinder each had two bands of holes, the holes in each band spaced 0.6 mm apart from each other. The aperturing method of Example 4 is summarized in Table 3. The resulting nonwoven web had the material properties shown in Table 2.

[0245] Comparative Example 5 (precursor web of Example 5)

[0246] A 25 gsm meltspun nonwoven batt was produced in-line from a mixture of polypropylene (type 3155E5 from Exxon) with a colorant additive (SCC 91056 from Standridge Color Corporation) in a continuous process, where monocomponent polypropylene filaments with a fiber diameter of 13-25 μιη were produced and subsequently collected on a moving belt. The batt was produced using REICOFIL 3.1 technology from four spunbond dies. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 1 FIG. 6 ) on the surface. The temperature of the calender rolls (smooth roll / embossed roll) was 160°C / 162°C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 2.

[0247] Example 5

[0248] The same nonwoven web was formed as described in Comparative Example 5, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 200 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two bands of holes, the holes within each band spaced 1.2 mm apart from each other. The second cylinder had a screen with the A1 pattern of bars (the bars spaced 4.5 mm apart from each other) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar, respectively, were used to hydro pattern the web with the pattern of apertures by forcing the web down onto the bars. The three jets at the second cylinder each had two bands of holes, the holes within each band spaced 0.6 mm apart from each other. The aperturing method of Example 5 is summarized in Table 3. The resulting nonwoven web had the material properties shown in Table 2.

[0249] Comparative Example 6 (precursor web of Example 6)

[0250] A 25 gsm melt-spun nonwoven batt was produced in-line from a mixture of polypropylene (Mosten NB425 from Unipetrol) and copolymer (Vistamaxx 6102 from Exxon) in a weight ratio of 75:15, a colorant additive (SCC 91056 from Standridge Color Corporation), and a softening additive based on erucamide (CESA-slipPP 42161 from Avient) in a continuous process. Single component polypropylene filaments with a fiber diameter of 13-25 pm were produced therein and subsequently collected on a moving belt. The batt was produced with the REICOFIL 3.1 technology from four dies. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 1 FIG. 6 ) applied to the surface of the roll. The temperature of the calender rolls (smooth roll / embossed roll) was 150 °C / 155 °C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 2.

[0251] Example 6

[0252] The same nonwoven web was formed as described in Comparative Example 6, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 200 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two rows of holes, the holes in each band spaced 1.2 mm apart from each other. The second cylinder had a screen with the A1 pattern of bars (the bars spaced 4.5 mm apart from each other) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar, respectively, were used to hydro pattern the web with the pattern of apertures by forcing the web down onto the bars. The three jets at the second cylinder each had two bands of holes, the holes in each band spaced 0.6 mm apart from each other. The aperturing method of Example 6 is summarized in Table 3. The resulting nonwoven web had the material properties shown in Table 2.

[0253]

[0254] Table 2

[0255]

[0256] Table 3

[0257] Comparative Example 7 (precursor web of Example 7)

[0258] A 35 gsm melt-spun nonwoven batt was produced in-line from a mixture of polypropylene (type 3155E5 from Exxon) with a colorant additive (SCC 91056 from Standridge Color Corporation) in a continuous process, where monocomponent polypropylene filaments of 13-25 μιη diameter were produced and subsequently collected on a moving belt. The batt was produced using REICOFIL 5 technology, from three spunbonding dies. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 3 FIG. 8 The temperature of the calender rolls (smooth roll / embossed roll) was 160°C / 162°C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 4.

[0259] Example 7

[0260] The same nonwoven web was formed as described in Comparative Example 7, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 150 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two rows of holes, the holes within each band spaced 1.2 mm apart from each other. The second cylinder had a screen with a Q5 pattern with sticks (cores) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar, respectively, were used to hydro pattern the web with the apertured pattern by forcing the web down onto the sticks. The three jets at the second cylinder each had two bands of holes, the holes within each band spaced 0.6 mm apart from each other. The aperturing method of Example 7 is summarized in Table 5. The resulting nonwoven web had the material properties shown in Table 4.

[0261] Comparative Example 8 (precursor web of Example 8)

[0262] A 25 gsm melt-spun nonwoven batt was produced in-line from a mixture of polypropylene (Mosten NB425 from Unipetrol) with a colored additive (SCC 91056 from Standridge Color Corporation) in a continuous process, where monocomponent polypropylene filaments with a fiber diameter of 13-25 pm were produced and subsequently collected on a moving belt. The batt was produced with three spunbond dies using REICOFIL 4 technology. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 1 FIG. 6 ) on the surface. The temperature of the calender rolls (smooth roll / embossed roll) was 160 °C / 162 °C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 4.

[0263] Example 8

[0264] The same nonwoven web was formed as described in Comparative Example 8, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 150 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two rows of holes, the holes within each band spaced 1.2 mm apart from each other. The second cylinder had a screen with a Q5 pattern with sticks (cores) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar, respectively, were used to hydro pattern the web with the apertured pattern by forcing the web down onto the sticks. The three jets at the second cylinder each had two bands of holes, the holes within each band spaced 0.6 mm apart from each other. The aperturing method of Example 8 is summarized in Table 5. The resulting nonwoven web had the material properties shown in Table 4.

[0265] Comparative Example 9 (precursor web of Example 9)

[0266] A 25 gsm melt-spun nonwoven batt was produced in-line from a mixture of polypropylene (Mosten NB425 from Unipetrol) with a colored additive (SCC 91056 from Standridge Color Corporation) in a continuous process, where monocomponent polypropylene filaments with a fiber diameter of 13-25 pm were produced and subsequently collected on a moving belt. The batt was produced with three spunbond dies using REICOFIL 4 technology. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 3 FIG. 8 ) on the surface. The temperature of the calender rolls (smooth roll / embossed roll) was 160 °C / 162 °C, and the bonding pressure was 75 N / mm. The resulting nonwoven web had the material properties shown in Table 4.

[0267] Example 9

[0268] The same nonwoven web was formed as described in Comparative Example 9, but with an additional hydroentanglement step. Hydroentanglement was achieved with two cylinders, the last one in the row providing the web with apertures. The first cylinder had a wire screen and one jet at the cylinder, which applied a water pressure of 150 bar to hydro treat the web before opening the apertures at the second cylinder. The one jet at the first cylinder had two rows of holes, the holes within each band spaced 1.2 mm apart from each other. The second cylinder had a screen with a Q5 pattern with bars (cores) as described herein. Three jets applying a water pressure of 220 bar, 220 bar, and 250 bar respectively were used to hydro pattern the web with the pattern of apertures by forcing the web down onto the bars. The three jets at the second cylinder each had two bands of holes, the holes within each band spaced 0.6 mm apart from each other. The aperturing method of Example 9 is summarized in Table 5. The resulting nonwoven web had the material properties shown in Table 4.

[0269] Comparative Example 10 (precursor web of Example 10)

[0270] A 30 gsm melt-spun nonwoven batt was produced in-line from core / sheath bicomponent filaments in a ratio of 80:20 in a continuous process. The core was formed from an aliphatic polyester (PLA Ingeo 6100D from Nature Works) and the sheath was formed from an aliphatic polyester with lower melting point and crystallinity (PLA Ingeo 6752s from Nature Works) with a slip additive (Avient CR Bio 2144 from Avient). Bicomponent filaments with a fiber diameter of 15-30 pm were produced and subsequently collected on a moving belt. The batt was produced from one spunbond die using REICOFIL 4 technology. The nonwoven batt was fully bonded by a pair of heated rolls, one of which had a raised pattern 1 FIG. 6 ) on the surface. The temperature of the calender rolls (smooth roll / embossed roll) was 140 °C / 138 °C and the bonding pressure was 50 N / mm. The resulting nonwoven web had the material properties shown in Table 4.

[0271] Example 10

[0272] The same nonwoven web was formed as described in Comparative Example 10, but with an additional hydroentanglement step. Hydroentanglement was achieved with two rolls, the last roll in the row provided the web with apertures. The first roll had a wire screen and one jet at the roll, 100 bar of water pressure was applied to hydro treat the web before aperturing at the second roll. The one jet at the first roll had two rows of holes, the holes in each band were spaced 1.2 mm apart from each other. The second roll had a screen with a Q5 pattern of bars (cores) as described herein. Three jets with 110 bar, 110 bar, and 120 bar of water pressure respectively were used to hydro pattern the web with the apertured pattern by forcing the web down onto the bars. The three jets at the second roll each had two bands of holes, the holes in each band were spaced 0.6 mm apart from each other. The aperturing method of Example 9 is summarized in Table 5. The resulting nonwoven web had the material properties shown in Table 4.

[0273]

[0274] Table 4

[0275]

[0276] Table 5

[0277] As can be seen in Table 2, each of the nonwoven webs described in Examples 1-6 were improved in thickness over their respective comparative examples, with an average increase of at least 100%. It is also important to note that the COF of each of the nonwoven webs described in Examples 1-6 was significantly higher than the COF of their respective comparative examples. Higher COF is generally preferred by converters such as diaper manufacturers because it prevents diaper-to-diaper slippage, particularly when diapers are tightly packed to fit multiple diapers in a single package. Although the tensile strength of each of the nonwovens described in Examples 1-6 was lower than the tensile strength of their respective comparative examples, it is important to note that each of the hydro patterned nonwoven webs described in Examples 1-6 provided a unique fabric to the hygiene product manufacturer that met typical product strength requirements and excellent abrasion resistance, while providing a visually distinct (apertured) fabric and higher thickness. Visual distinctness is a function of fiber modulus, which is created by its composition and / or additives, in combination with the bonding pattern and bar geometry used to calender the bonded precursor web. The hydro apertured sample with the best visual distinctness and abrasion performance was the result of the fiber without softening additives and the hot bonding pattern that overlaid with minimal conflict to the aperturing roll design to allow the creation of the aperture via movement of the fibers. This is demonstrated by Example 3, which had the lowest abrasion performance, but had good visual distinctness, while Example 5 had similar visual distinctness, but had superior abrasion performance due to the difference in calender bonding geometry.

[0278] It should be noted that the tensile strength drop of the web during hydroentanglement is not always the key parameter to evaluate. In the case of polyolefin-based fabrics, the tensile drop usually needs to be as small as possible to meet the converter and end product requirements. In contrast, Example 10 provides a polyester-based fabric with a fairly high tensile strength. PLA-based nonwoven webs usually have a higher tensile strength, lower elongation, and higher HOM values. The hydroentanglement of the PLA-based nonwoven according to the present application can cause a relatively high tensile strength drop (-67% in MD and -56% in CD) to values similar to those of polyolefin-based fabrics. But more importantly, the softness indicators, in particular the HOM, also drop to values closer to the desired level of polyolefin (average HOM from 22.8 to 7.8), and even the open fabric provides a higher caliper than the precursor (thicker fabrics usually provide higher HOM values). Moreover, the abrasion resistance remains high (close to 4 after hydroentanglement) and the visual clarity is perfect.

[0279] While in the foregoing specification this application has been described in relation to certain specific embodiments thereof, it is to be understood that many other changes can be made which will embody the purpose and broad aspects of the application, and the general principles of the or the same.

[0280] Test Methods

[0281] The "tensile strength" and "elongation" of the nonwoven fabric are measured according to the WSP 110.4.R4(12) standard using the test method. The tensile strength can also be expressed as "MDT" for the MD direction and "CDT" for the CD direction. Thus, the elongation can also be expressed as "MDE" for the MD direction and "CDE" for the CD direction.

[0282] The "Handle-O-Meter" or "HOM" stiffness test of the nonwoven material is performed according to the WSP test method 90.3 with slight modifications. The quality of the "hand" is considered to be a combination of resistance due to surface friction and bending stiffness of the sheet. The equipment for this test method is available from Thwing Albert Instrument Co. In this test method, a 100 x 100 mm sample is used for the HOM measurement and the final reading obtained is reported as "as is" in grams, without doubling the reading according to the WSP test method 90.3. The average HOM is obtained by taking the average of the MD and CD HOM values. In general, the lower the HOM value, the higher the softness and flexibility, while a higher HOM value means a lower softness and flexibility of the nonwoven fabric.

[0283] The "thickness" or "caliper" of a nonwoven material is determined by the test method according to European Standard EN ISO 9073-2:1995 (corresponding to method WSP 120.6) modified in the following way:

[0284] 1. The material is measured by using a sample taken from the manufacturing which is not subjected to higher deformation forces or to pressure action for more than one day (for example by the pressure exerted by the rolls on the manufacturing equipment) but the material has to be placed on a surface free standing for at least 24 hours.

[0285] 2. The total pressure for the thickness measurement is 14.7 g / cm2.

[0286] 3. When the fabric provides a difference in thickness between the edge of the hole and the nonwoven itself, the value of the nonwoven between the holes should be considered as the measured value.

[0287] The "coefficient of kinetic friction" or "kinetic CoF" of a nonwoven material is determined by using a testing Machines Inc. 32-07 Series Friction Tester according to ASTM D 1894 standard. The reported data represent the kinetic coefficient of friction (CoF) of a nonwoven against itself on a 10 cm x 10 cm nonwoven sample placed under a 200 g sled pulled over a 25 cm x 10 cm clamped sample of the same nonwoven, keeping the side slip and the orientation consistency (A side to A side; MD direction to MD direction) at 150 mm / min speed.

[0288] The "visual clarity" is determined visually by at least five people independently by naked eye according to the Hole Clarity Visual Rating Scale (see FIG. 16 ) by at least three of the five people (or at least 3 / 5 of the evaluation group) are required to have the same evaluation on each fabric in order to record the evaluation. Single assessments that are not in agreement with the other at least three evaluations are not counted.

[0289] The "Martindale Average Abrasion Resistance Rating Test" or "Martindale"

[0290] FIG. 17 is a perspective view of the equipment for the Martindale Average Abrasion Resistance Rating Test. In particular, FIG. 17 a rating scale for the pile evaluation in the Martindale Average Abrasion Resistance Rating Test is shown.

[0291] The average abrasion resistance rating of a nonwoven is measured using a Martindale Abrasion Tester. The test is performed dry.

[0292] The nonwoven samples are conditioned at 23 ± 2 °C and 50 ± 2 % relative humidity for 24 hours.

[0293] Ten 162 mm (6.375 inch) diameter circular samples were cut from each nonwoven sample. One piece of standard felt was cut into a 140 mm diameter circle.

[0294] Each sample was secured in each test abrader station on a Martin Dawbarn by first placing the cut felt, then the cut nonwoven sample. The clamping ring was then secured so that no wrinkles were visible on the nonwoven sample.

[0295] The abrasive holder was assembled. The abrasive was 38 mm diameter FDA compliant 1 / 32 inch thick silicone rubber (from McMaster Carr, item 86045K21-50A). The desired weight was placed in the abrasive holder to exert a 9 kPa pressure on the sample. The assembled abrasive holder was placed in the #864 type Martin Dawbarn so that the abrasive contacted the NW sample as indicated in the operator’s guide.

[0296] The Martin Dawbarn was operated under the following conditions:

[0297] Mode: Abrasion test

[0298] Speed: 47.5 cycles / minute; and

[0299] Cycles: 80 cycles

[0300] After the test was stopped, the abraded nonwoven was placed on a smooth, matte, black surface and its nub level was graded using the scale provided in FIG. 17 Each sample was evaluated by viewing from the top to determine the size and number of defects, and from the side to determine the loft height of the defects. A number from 5 to 1 was assigned based on the best match to the grading scale. The Martin Dawbarn average abrasion resistance grade was then calculated as the average rating of all samples and reported to the nearest tenth.

[0301] “Percent Bond Area” was determined using ImageJ software (Vs. 1.43u, National Institutes of Health, USA) by identifying the single repeating pattern of bond impressions and un-bonded areas and zooming in on the image so that the repeating pattern filled the field of view. A box was drawn in ImageJ that contained the repeating pattern. The area of the box was calculated and recorded to the nearest 0.01 mm 2 . Next, with the area tool, individual bond impressions or their entirety within the box were traced and the area of all bond impressions or their entirety within the box was calculated. This was recorded to the nearest 0.01 mm 2 . Percent Bond Area was calculated as follows:

[0302] Percent Bond Area = (sum of areas of bond impressions within the frame) / (area of frame) x 100%

[0303] Repeat a total of five non-adjacent ROIs randomly selected throughout the sample. Record the percent bond area to the nearest 0.01%. Measure two samples from each article. Measure a total of three identical articles for each sample set. Calculate the average and standard deviation of the percent of all 30 bond area measurements and report to the nearest 0.001 units.

Claims

1. A method of forming an apertured hydroentangled nonwoven web comprising: forming a nonwoven batt comprising continuous meltspun fibers; calender bonding the nonwoven batt to form a fully bonded precursor nonwoven web having a regular bond pattern defining individual bond impressions and unbonded areas between the individual bond impressions, the regular bond pattern having a bond area percentage of 10% to 25%; and hydroentifying the fully bonded precursor nonwoven web with a plurality of apertures, the hydroentifying step comprising hydroprocessing the fully bonded precursor nonwoven web by a plurality of water jet steps as the fully bonded nonwoven web passes a plurality of bars.

2. The method of claim 1, wherein each of the bars has a base and a top, wherein the base has an area greater than the area of the top.

3. The method of claim 1, wherein each bar is symmetrical about a longitudinal axis of the bar.

4. The method of claim 1, wherein each bar has a base, and the distance between the centers of immediately adjacent bars is at least 100% of the diameter of the base.

5. The method of claim 1, wherein the height of the bars is at least 100% of the thickness of the apertured nonwoven web.

6. The method of claim 1, wherein the height of the bars is at least 115% of the thickness of the apertured nonwoven web.

7. The method of claim 1, wherein the height of the bars is at least 200% of the thickness of the precursor nonwoven web.

8. The method of claim 1, wherein the bars are disposed on a surface that is moving at substantially the same speed as the calender bonded precursor nonwoven web.

9. The method of claim 1, wherein the bars vary in size and / or shape, and are disposed on a screen or belt, and the distance between the centers of immediately adjacent bars is at least 100% of the diameter of the base of the largest bar.

10. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: the meltspun fibers of the nonwoven batt are comprised of spunbond filaments.

11. The method of claim 10, wherein the step of forming the precursor nonwoven web comprises: the nonwoven batt comprises two or more layers.

12. The method of claim 11, wherein the step of forming the precursor nonwoven web comprises: the meltspun fibers in each of the two or more layers comprise spunbond filaments.

13. The method of claim 11, wherein the step of forming the precursor nonwoven web comprises an average fiber thickness difference between the layers of less than 20%.

14. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: the nonwoven batt comprises two or more layers, at least one of the two or more layers comprises spunbond filaments, and at least one other of the two or more layers comprises meltblown fibers.

15. The method of claim 13, wherein the step of forming the precursor nonwoven web comprises: at least one layer comprising spunbond filaments forms at least one outer layer of the nonwoven batt.

16. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: the nonwoven batt comprises three or more layers, and the three or more layers form a spunbond-meltblown-spunbond (SMS) structure.

17. The method of claim 1, further comprising the step of applying at least one layer formed of fibers and / or particles to the fully bonded precursor nonwoven web prior to the hydroprocessing step.

18. The method of claim 17, wherein the fibers are staple synthetic fibers.

19. The method of claim 17, wherein the fibers are natural fibers.

20. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: The continuous melt-spun fibers are monocomponent fibers formed from thermoplastic polymers.

21. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: The continuous melt-spun fibers are monocomponent fibers formed from polyolefin or polyester or polyamide based homopolymers, copolymers or polymer blends.

22. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: The continuous melt-spun fibers are multicomponent fibers, and wherein each component is formed from a thermoplastic polymer.

23. The method of claim 22, wherein the continuous melt-spun fibers are bicomponent fibers.

24. The method of claim 22, wherein each component is formed from polyolefin or polyester or polyamide based homopolymers, copolymers or polymer blends.

25. The method of claim 22, wherein at least 40% of the component polymer composition present on the surface of each filament has a lower melting temperature than the melting temperature of at least one other component polymer composition.

26. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: The continuous melt-spun fibers comprise polyolefin or polyamide or polyester or polysaccharide homopolymers, copolymers or polymer blends.

27. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: The continuous melt-spun fibers comprise polypropylene, polyethylene, polylactic acid, polyhydroxyalkanoate, polyhydroxybutyrate, polybutylene succinate, polyethylene terephthalate, thermoplastic starch, copolymers thereof, copolymers thereof with olefins, esters, amides or other polymers, or blends thereof.

28. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: The continuous melt-spun fibers are bicomponent core-sheath fibers having a core comprising polypropylene and a sheath comprising a blend of polypropylene and polypropylene-polyethylene copolymer.

29. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: The continuous melt-spun fibers comprise an additive.

30. The method of claim 29, wherein the additive comprises an additive selected from the group consisting of a color pigment, a softening enhancer, a slip aid, a filler, and combinations thereof.

31. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises: forming a bond impression having a bond shape.

32. The method of claim 31, wherein the bond impression has a first dimension, and the bond impression is formed from a bond point having a second dimension, wherein the second dimension is less than the first dimension.

33. The method of claim 31, wherein the bond shape is oriented such that a line intersecting a perimeter of the bond shape having a maximum measurable length along the perimeter of the bond shape intersects an axis lying on the surface along the machine direction to form an angle aT of 0 degrees to 65 degrees.

34. The method of claim 31, wherein the bond shape comprises a convex portion.

35. The method of claim 31, wherein the bond shape comprises a concave portion.

36. The method of claim 31, wherein the bond shape comprises at least one of a convex portion and a concave portion.

37. The method of claim 31, wherein the bond shape is asymmetric.

38. The method of claim 31, wherein the bond impression has a bond shape, and the bond shape is elliptical.

39. The method of claim 31, wherein the bond impression has a bond shape, and the bond shape is a line.

40. The method of claim 31, wherein the bond impression has a bond shape, the bond shape having a bond shape perimeter, the bond shape perimeter having a maximum measurable length and a maximum measurable width.

41. The method of claim 40, wherein an aspect ratio of the maximum measurable length to the maximum measurable width is at least 1.

0.

42. The method of claim 31, wherein the fully bonded precursor nonwoven web comprises at least 20 bond impressions per square centimeter.

43. The method of claim 31, wherein a bond impression line intersecting the bond shape perimeter where the maximum measurable length exists along the bond shape perimeter intersects an axis lying on a surface along a machine direction to form an angle aT of 20 degrees to 80 degrees.

44. The method of claim 31, wherein the step of forming the precursor nonwoven web comprises forming the fully bonded precursor nonwoven web with less than 20 bond impressions per square centimeter.

45. The method of claim 44, wherein the bond impression has a bond shape, the bond shape having a bond shape perimeter, the bond shape perimeter having a maximum measurable length and a maximum measurable width, and an aspect ratio of the maximum measurable length to the maximum measurable width is at least 2.

0.

46. The method of claim 44, wherein the bond shape is a line.

47. The method of claim 44, wherein the bond shape is an S shape.

48. The method of claim 45, wherein the bond impression has a bond shape, the bond shape having a bond shape perimeter, the bond shape perimeter having a maximum measurable length and a maximum measurable width, and a bond impression line intersecting the bond shape perimeter where the maximum measurable length exists along the bond shape perimeter intersects an axis lying on a surface along a machine direction to form an angle aT of 5 degrees to 15 degrees.

49. The method of claim 1, wherein the step of forming the precursor nonwoven web comprises forming bond impressions in the form of a quilt pattern.

50. The method of claim 49, wherein the bond impressions of the quilt pattern have a quilt pattern line intersecting an imaginary line extending along a machine direction to form an angle aTq of 5 degrees to 60 degrees.

51. The method of claim 1, wherein the precursor nonwoven web has an MD HOM value of at least 5 g.

52. The method of claim 1, wherein the precursor nonwoven web has a CD HOM value of at least 2 g.

53. The method of claim 1, wherein the precursor nonwoven web has an MD HOM value of 30 g or less.

54. The method of claim 1, wherein the precursor nonwoven web has a CD HOM value of 20 g or less.

55. The method of claim 1, wherein the precursor nonwoven web has a basis weight of at least 5 gsm.

56. The method of claim 1, wherein the precursor nonwoven web has a basis weight of 60 gsm or less.

57. The method of claim 1, wherein the step of hydroentangling comprises applying water pressure to the precursor nonwoven web with water jets.

58. The method of claim 57, wherein the water pressure applied to the precursor nonwoven web represents an energy flux of at least 0.2 kWh / kg.

59. The method of claim 57, wherein the water pressure applied to the precursor nonwoven web represents an energy flux of 3.0 kWh / kg or less.

60. The method of claim 57, wherein the step of hydroentangling comprises applying water pressure to the precursor nonwoven web through at least two groups of water jets.

61. The method of claim 57, wherein the method is conducted at a line speed of at least 150 m / min.

62. The method of claim 61, wherein the line speed is 450 m / min or less.

63. The method of claim 57, wherein the step of hydroentangling comprises applying water pressure to the precursor nonwoven web through three groups of water jets, each group of water jets applying a pressure of 150 bar or greater.

64. The method of claim 57, wherein the step of hydroentangling comprises applying water pressure to the precursor nonwoven web through three groups of water jets, each group of water jets applying a pressure that is greater than the pressure applied by a group of water jets preceding the group of water jets in the machine direction.

65. The method of claim 64, wherein the three groups of water jets comprise a first group of water jets, a second group of water jets preceding the first group of water jets in the machine direction, and a third group of water jets preceding the first group of water jets and the second group of water jets in the machine direction, the second group of water jets applying a pressure that is 80% to 95% of the pressure applied by the first group of water jets, and the third group of water jets applying a pressure that is 64% to 90% of the pressure applied by the second group of water jets.

66. The method of claim 57, wherein the step of hydroentangling comprises applying water pressure to the precursor nonwoven web through three groups of water jets, each water jet applying a pressure of 200 bar or greater.

67. The method of claim 57, wherein the step of hydroentangling comprises applying water pressure to the precursor nonwoven web through two groups of water jets, each water jet applying a pressure of 300 bar or greater.

68. The method of claim 57, wherein the step of hydroentangling comprises applying a water jet to the calender bonded precursor nonwoven web at an angle of 80° to 100° relative to the calender bonded precursor nonwoven web.

69. The method of claim 1, wherein the step of hydroentangling the fully bonded precursor nonwoven web comprises at least partially altering the individual bond impressions by applying water pressure.

70. The method of claim 69, wherein the step of at least partially altering results in at least 60% of a fully bonded portion of the individual bond impressions remaining after the step of hydroentangling.

71. The method according to claim 69, wherein said step of at least partially altering results in at least 70% of the fully bonded portion of each bond impression remaining after said hydrodynamic imposition step.

72. The method according to claim 69, wherein said step of at least partially altering results in at least 80% of the fully bonded portion of each bond impression remaining after said hydrodynamic imposition step.

73. The method according to claim 69, wherein said step of at least partially altering results in at least 90% of the fully bonded portion of each bond impression remaining after said hydrodynamic imposition step.

74. The method according to claim 69, wherein said step of at least partially altering results in the division of each bond impression into at least two portions.

75. The method according to claim 69, wherein said step of at least partially altering results in fibers in the area around the perimeter of each bond impression being randomly ground into and out of the plane of the fully bonded precursor nonwoven web so as to at least partially eliminate the three-dimensionality of each bond impression.

76. An apertured hydrodyamcally patterned nonwoven web produced according to the method of claim 1.

77. The apertured hydrodyamcally patterned nonwoven web of claim 76, wherein the web has a basis weight of 60 gsm or less.

78. The apertured hydrodyamcally patterned nonwoven web of claim 76, wherein the web has an MD tensile strength of at least 4 N / cm.

79. The apertured hydrodyamcally patterned nonwoven web of claim 76, wherein the web has a CD tensile strength of at least 2 N / cm.

80. The apertured hydrodyamcally patterned nonwoven web of claim 76, wherein the web has a thickness of at least 12 microns / gsm of fabric.

81. The apertured hydrodyamcally patterned nonwoven web of claim 76, wherein the web does not exhibit two-sidedness in terms of abrasion rating.

82. The apertured hydrodyamcally patterned nonwoven web of claim 76, wherein the web does not exhibit two-sidedness in terms of coefficient of friction.

83. The apertured hydrodyamcally patterned nonwoven web of claim 76, wherein the web has a visual aperture clarity of at least 3 on a scale of 1 to 5.

84. A method of forming an apertured hydrodyamcally patterned nonwoven web, comprising: providing a fully bonded precursor nonwoven web having a regular bond pattern defining each bond impression and unbonded areas between the each bond impression, the regular bond pattern having a bond area percentage of 10% to 25%; and hydrodyamcally treating the fully bonded precursor nonwoven web by a plurality of water jet steps as the fully bonded nonwoven web passes a plurality of bars so as to form a plurality of apertures in the fully bonded precursor nonwoven web.

Images