Hydropatterned nonwoven fabric and its manufacturing method

Abstract

A method of forming a hydropatterned nonwoven fabric, comprising the steps of: forming a nonwoven batt comprised of continuous spunmelt fibers; calendaring the nonwoven batt to form a thermally bonded precursor nonwoven fabric having a bonding pattern defining bonding impressions and unbonded areas between individual bonding impressions; and hydrotreating the thermally bonded precursor nonwoven fabric with multiple passes of water jets as the thermally bonded nonwoven fabric passes over a screen, the bonding pattern having certain characteristics that provide advantages in terms of mechanical properties and appearance of the final nonwoven product.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 183,148, filed May 3, 2021, entitled "HYDRO-PATTERNED NONWOVEN AND METHOD OF MAKING THE SAME," the contents of which are incorporated by reference in their entirety into this specification.

[0002] The present invention relates to hydro-patterned nonwoven fabrics and an improved method for making hydro-patterned nonwoven fabrics in which a bonded pattern is imparted to the nonwoven fabric prior to subjecting it to a water pressure treatment. [Background technology]

[0003] Spunmelt nonwovens (e.g., spunbond nonwovens, meltblown nonwovens, and combinations thereof) are formed from thermoplastic continuous fibers, bicomponent or multicomponent fibers, such as polypropylene (PP), polyethylene terephthalate (PET), and blends of such spunmelt fibers with rayon, cotton, cellulosic pulp fibers, and the like. Traditionally, spunmelt nonwovens are thermally bonded, ultrasonically bonded, chemically bonded (e.g., with latex), or resin bonded, and the bonds are nearly indestructible and unaffected by post-bonding processing and conversion. Thermal and ultrasonic bonds provide permanent fusion, while chemical bonds may or may not be permanent.

[0004] It is known to subject fabrics to hydraulic treatment to improve their properties such as softness and bulk. For example, U.S. Patent No. 7,858,544 and U.S. Patent No. 10,767,296 describe one known hydraulic treatment process called hydraulic expansion. It is also known to form holes in nonwoven fabrics in a number of ways using different technological processes.

[0005] There is a need for a method to form hydropatterned nonwoven fabrics from thermally bonded precursor fabrics that results in products with an improved combination of properties such as softness, abrasion resistance, and tensile strength.

[0006] A method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention includes: forming a nonwoven batt of continuous spunmelt fibers; calendering the nonwoven batt to form a thermally bonded precursor nonwoven fabric having a bond pattern defining bond impressions and non-bonded areas between individual bond impressions; and a step of hydraulically treating the thermally bonded precursor nonwoven fabric with multiple water jets as the thermally bonded precursor nonwoven fabric passes over a screen. Including, The adhesive area of ​​the adhesive pattern is 10% to 25% in percentage, defining a virtual circle C as the largest circle delineable between the non-bonded regions and having a perimeter that intersects with a point on the perimeter of each of at least two adjacent bonded impressions in the bond pattern, the circle C having a radius of at least 0.5 mm, preferably at least 1.0 mm, more preferably at least 1.5 mm, and even more preferably at least 2.0 mm in the non-bonded regions; The adhesive pattern has an adhesive impression area of ​​at least 1 mm 2 The resulting bond consists of large-bold bonding impressions It is characterized by:

[0007] In an exemplary embodiment, in the step of forming the precursor fabric, the spunmelt fibers of the nonwoven batt are comprised of spunbond filaments.

[0008] In an exemplary embodiment, in the step of forming the precursor fabric, the nonwoven batt comprises two or more layers.

[0009] In an exemplary embodiment, the spunmelt fibers in each of the two or more layers comprise spunbond filaments.

[0010] In an exemplary embodiment, the difference in average fiber thickness between the layers is less than 20%, preferably less than 15%, more preferably less than 10%, and even more preferably less than 5%.

[0011] In an exemplary embodiment, at least one of the two or more layers is comprised of spunbond filaments and at least one other of the two or more layers is comprised of meltblown fibers.

[0012] In an exemplary embodiment, at least one layer of the spunbond filaments forms at least one outer layer of the nonwoven batt.

[0013] In an exemplary embodiment, the two or more layers comprise at least three layers forming a spunbond-meltblown-spunbond (SMS) structure.

[0014] In an exemplary embodiment, the method further includes the step of applying at least one layer formed from fibers and / or particles to the fully bonded nonwoven precursor fabric prior to the hydrotreating step.

[0015] In an exemplary embodiment, the fibers are short synthetic fibers, preferably polyester staple fibers or viscose fibers.

[0016] In an exemplary embodiment, the fibers are natural fibers, preferably cotton fibers or pulp, or modified cellulose such as rayon.

[0017] In an exemplary embodiment, in the step of forming the precursor fabric, the continuous spunmelt fibers are comprised of a polyolefin, or a polyamide, or a polyester, or a polysaccharide homopolymer, copolymer, or polymer blend.

[0018] In an exemplary embodiment, in the step of forming the precursor fabric, the continuous spunmelt fibers are comprised of 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.

[0019] In an exemplary embodiment, in the step of forming the precursor fabric, the spunmelt fibers comprise multicomponent, preferably bicomponent, continuous spunmelt fibers.

[0020] In an exemplary embodiment, the melting temperature of one component polymer composition present in an area of ​​at least 40% of each filament surface, preferably at least 50% of each filament surface, more preferably at least 60% of each filament surface, and even more preferably the entire surface of each filament, is lower than the melting temperature of at least one other component polymer composition by a difference of at least 2°C, more preferably at least 5°C.

[0021] In an exemplary embodiment, in the step of forming the precursor fabric, the spunmelt fibers comprise bicomponent core-sheath continuous spunmelt fibers having a core comprised of polypropylene and a sheath comprised of a blend of polypropylene and copolymer polypropylene-polyethylene.

[0022] In an exemplary embodiment, the continuous spunmelt fibers include an additive.

[0023] In an exemplary embodiment, the additive comprises a type of additive selected from the group consisting of: color pigments, softness enhancers, lubricants, fillers, and combinations thereof.

[0024] In an exemplary embodiment, in the step of forming the precursor fabric, the adhesive pattern has an adhesive impression area of ​​1 mm 2 The adhesive comprises small diameter like adhesive indentations having a diameter less than 1 mm.

[0025] In an exemplary embodiment, in the step of forming the precursor fabric, the radius of circle C is at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm, and even more preferably at least 4 mm.

[0026] In an exemplary embodiment, in the step of forming the precursor fabric, the minimum distance between adjacent adhesive impressions is at least 0.3 mm, preferably at least 0.4 mm, and more preferably at least 0.5 mm.

[0027] In an exemplary embodiment, in the process of forming the precursor fabric, the adhesive impression is a line shape of a constant width, with a line width (W) of up to 0.6 mm, preferably up to 0.5 mm, and most preferably up to 0.4 mm.

[0028] In an exemplary embodiment, in the process of forming the precursor fabric, the adhesive impressions are in the form of lines of irregular width having a line width (W) of up to 0.6 mm, preferably up to 0.5 mm, and most preferably up to 0.4 mm.

[0029] In an exemplary embodiment, in the step of forming the precursor fabric, the adhesive impression is a line shape having an outer adhesive shape periphery that includes at least one protrusion.

[0030] In an exemplary embodiment, in the step of forming the precursor fabric, the adhesive impression is in the form of a continuous line.

[0031] In an exemplary embodiment, in the step of forming the precursor fabric, the adhesive impression is in the form of a line having a length (L) of up to 30 mm, preferably up to 25 mm, and more preferably up to 20 mm.

[0032] In an exemplary embodiment, in the step of forming the precursor fabric, the adhesive pattern has an adhesive impression area of ​​1 mm 2 The adhesive indentations are of a large diameter.

[0033] In an exemplary embodiment, the water pressure treating step includes applying water pressure to the nonwoven precursor fabric with a water jet.

[0034] In an exemplary embodiment, the water pressure treating step includes applying water pressure to the nonwoven precursor fabric with at least two sets of water jets.

[0035] In an exemplary embodiment, this is done at a line speed of at least 150 m / min.

[0036] In an exemplary embodiment, the line speed is less than or equal to 450 m / min.

[0037] A hydropatterned nonwoven fabric according to an exemplary embodiment of the present invention is produced by a process including any of the steps described above.

[0038] In an exemplary embodiment, the hydropatterned nonwoven fabric has a basis weight of 60 gsm or less, preferably 50 gsm or less, more preferably 45 gsm or less, and even more preferably 35 gsm or less.

[0039] In an exemplary embodiment, the hydropatterned nonwoven fabric has a MD tensile strength of at least 4 N / cm.

[0040] In an exemplary embodiment, the hydropatterned nonwoven fabric has a CD tensile strength of at least 2 N / cm.

[0041] In an exemplary embodiment, the hydropatterned nonwoven fabric has a caliper of at least 10 microns / gsm of fabric, preferably at least 11 microns / gsm of fabric, and most preferably at least 12 microns / gsm of fabric.

[0042] In an exemplary embodiment, the water pressure treatment step includes applying water pressure to the nonwoven precursor fabric by one or more sets of the water jet devices, each set of water jet devices applying a water pressure higher than the water pressure applied by a set of water jet devices preceding it in the machine direction.

[0043] In an exemplary embodiment, the one or more sets of water injection devices include a first set of water injection devices, a second set of water injection devices preceding the first set of water injection devices in the machine direction, and a third set of water injection devices preceding the first and second sets of water injection devices in the machine direction, wherein the second set of water injection devices apply a water pressure that is 80% to 95% of the water pressure applied by the first set of water injection devices, and the third set of water injection devices apply a water pressure that is 64% to 90% of the water pressure applied by the second set of water injection devices.

[0044] In an exemplary embodiment, the water pressure treating step includes at least partially altering individual ones of the adhesive impressions by application of the water pressure.

[0045] In an exemplary embodiment, the at least partially altering step results in at least 60% of each of the adhesive impressions remaining fully bonded after the applying water pressure step.

[0046] In an exemplary embodiment, the at least partially altering step results in at least 70% of each of the adhesive impressions remaining fully bonded after the applying water pressure step.

[0047] In an exemplary embodiment, the at least partially altering step results in at least 80% of each of the adhesive impressions remaining fully bonded after the applying water pressure step.

[0048] In an exemplary embodiment, the at least partially altering step results in at least 90% intact adhesion of each of the adhesive impressions remaining after the applying water pressure step.

[0049] In an exemplary embodiment, the at least partially varying step separates each of the adhesive impressions into at least two portions.

[0050] In an exemplary embodiment, the at least partially transforming step causes fibers in an area around the perimeter of each of the adhesive impressions to randomly fray in and out of the major plane of the fully bonded precursor nonwoven fabric, such that at least a portion of each of the adhesive impressions are no longer three-dimensional.

[0051] A method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention includes: forming a nonwoven batt of continuous spunmelt fibers; calendering the nonwoven batt to form a thermally bonded precursor nonwoven fabric having a bond pattern defining bond impressions and non-bonded areas between individual bond impressions; and a step of hydraulically treating the thermally bonded precursor nonwoven fabric with multiple water jets as the thermally bonded precursor nonwoven fabric passes over a screen. Including, The adhesive area of ​​the adhesive pattern is 10% to 25% in percentage, The adhesive pattern has an adhesive impression area of ​​1 mm 2 The adhesive pattern comprises small diameter adhesive indentations having an area of ​​adhesive indentations of at least 1 mm 2 The adhesive indentation is made up of large diameter like adhesive indentations.

[0052] A method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention includes: forming a nonwoven batt of continuous spunmelt fibers; calendering the nonwoven batt to form a thermally bonded precursor nonwoven fabric having a bond pattern defining bond impressions and non-bonded areas between individual bond impressions; and a step of hydraulically treating the thermally bonded precursor nonwoven fabric with multiple water jets as the thermally bonded precursor nonwoven fabric passes over a screen. Including, The adhesive area of ​​the regular adhesive pattern is 10% to 25% in percentage, The adhesive pattern formed in the calendaring step has an adhesive impression area of ​​at least 1 mm 2 It consists of a large diameter adhesive indentation, The adhesive impression is a line shape of irregular width with a maximum line width (W) of up to 0.6 mm, preferably up to 0.5 mm, most preferably up to 0.4 mm, The adhesive impression is in the form of a line having a length (L) of up to 30 mm, preferably up to 25 mm, more preferably up to 20 mm.

[0053] The above and related objects, features, and advantages of the present invention will be more fully understood by reference to the following detailed description of preferred but illustrative embodiments of the invention, taken in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0054] [Figure 1] FIG. 1 is a representative diagram of a system for forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 2A] FIG. 1 is a representative diagram of a system for forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 2B] FIG. 1 is a representative diagram of a system for forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 3A] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 3B] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 3C] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 3D] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 4A]1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 4B] 4A on a precursor fabric according to an exemplary embodiment of the present invention; [Diagram 5] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 6A] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 6B] 6A on a precursor fabric according to an exemplary embodiment of the present invention; [Figure 7A] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 7B] 7A on a precursor fabric according to an exemplary embodiment of the present invention; [Figure 8A] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 8B] 8A on a precursor fabric according to an exemplary embodiment of the present invention; [Figure 9] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 10A] 1 illustrates a bond pattern that can be used in a method of forming a hydropatterned nonwoven textile according to an exemplary embodiment of the present invention; [Figure 10B] 10A on a precursor fabric according to an exemplary embodiment of the present invention; [Figure 11] Table 1 lists certain characteristics of various bond patterns that can be used in the method of forming a hydropatterned nonwoven fabric according to an exemplary embodiment of the present invention; [Figure 12A] 1 is a photomicrograph of a bond pattern on a precursor fabric according to an exemplary embodiment of the present invention; [Figure 12B] 12B is a photomicrograph of a hydropatterned nonwoven fabric formed from the precursor fabric of FIG. 12A in accordance with an exemplary embodiment of the present invention; [Figure 13] 1 is a perspective view of a grading device for evaluating fuzz in the Martindale Average Abrasion Resistance Rating Test; [Figure 14] Martindale abrasion test method grade index; [Figure 15A] 1 shows in cross section the variation of an individual adhesive impression resulting from the process of an exemplary embodiment of the present invention; [Figure 15B] 1 shows in cross section the variation of an individual adhesive impression resulting from the process of an exemplary embodiment of the present invention; [Figure 15C] 1 shows in cross section the variation of an individual adhesive impression resulting from the process of an exemplary embodiment of the present invention; [Figure 15D] 1 shows in cross section the variation of an individual adhesive impression resulting from the process of an exemplary embodiment of the present invention; [Figure 15E] 1 is a photomicrograph showing in cross section the evolution of individual adhesive indentations resulting from a conventional hydraulic treatment process; [Figure 15F] 1 is a photomicrograph showing in cross section the evolution of individual adhesive indentations resulting from a conventional hydraulic treatment process; [Figure 16A] 1 is a plan view of a patterned nonwoven textile before and after water pressure treatment in accordance with an exemplary embodiment of the present invention; [Figure 16B] 1A-1C are plan views of patterned nonwoven textiles before and after water pressure treatment in accordance with an exemplary embodiment of the present invention.

[0055] Detailed Description of the Invention The present invention relates to an improved technique for hydro-treating nonwoven fabrics, and nonwoven fabrics made using the method. The hydro-treated fabrics described herein are referred to as "hydro-patterned" fabrics.

[0056] Nonwoven fabrics hydraulically treated according to the present invention may be suitable for use in disposable absorbent articles. As used herein, the term "absorbent article" refers to an article that absorbs and retains fluids and solids. For example, the absorbent article may be placed directly on or in close proximity to the body to absorb and retain various exudates discharged from the body. The absorbent article may be a worn article such as an infant diaper, an adult incontinence product, a feminine care product, or a sanitary product used to absorb fluids and solids, for example for medical personnel using products such as disposable gowns and zippers. In particular, nonwoven fabrics according to exemplary embodiments of the present invention may be used as or as part of a body contacting layer of an absorbent article, such as a topsheet, or may be used to form other components of the absorbent article, such as, for example, a backsheet, a waist belt, or fastening tabs. Nonwoven fabrics according to exemplary embodiments of the present invention may also be used to package or wrap articles such as absorbent articles. The term "disposable" is used herein to describe absorbent articles that are not intended to be laundered or restored or reused as absorbent articles, but instead are intended to be discarded after a single use, and preferably recycled, composted, or disposed of in an environmentally compatible manner.

[0057] The term "disposable" is used herein to describe absorbent articles that are not intended to be laundered or restored or reused as absorbent articles, but instead are intended to be discarded after a single use, and preferably recycled, composted, or disposed of in an environmentally compatible manner.

[0058] The terms "fiber" and "filament" are used interchangeably herein unless otherwise specified (e.g., "endless filament" or "staple fiber").

[0059] The term "batt" is used herein to refer to multiple fibrous materials before they are bonded together. A "batt" usually consists of individual fibers that are not bonded together, but there may be some degree of pre-bonding between the fibers, which may occur, for example, during or immediately after the laying of the fibers in a spunmelt process. However, this pre-bonding still leaves a significant number of the fibers free to move and reposition. A "batt" may be composed of several layers obtained by depositing fibers from several spinning heads in a spunmelt process. The "sub-layers" laid down from the individual heads do not have significant differences in fiber diameter and porosity distribution. Adjacent layers of fibers need not be separated from each other by an abrupt transition, and the individual layers may be partially intermixed in the regions near their boundaries.

[0060] As used herein, the term "nonwoven, nonwoven, sheet, or fabric" refers to a sheet or fabric made from directional or randomly oriented fibers or filaments. These fibers or filaments are first formed into batts and then laid one or more batts on top of each other and consolidated and bonded together. Consolidation and bonding is achieved by friction, cohesion, adhesion, or one or more patterns of bonding and bonding impressions resulting from localized compression and / or the application of pressure, heat, ultrasonic, or heating energy, or a combination thereof. This term does not include fabrics bonded by weaving, knitting, or sewing of yarns or filaments. The fibers may be of natural or synthetic origin, staple or continuous filaments, and may be formed in situ. Commercially available fibers have diameters ranging from about 0.0005 mm to about 0.25 mm and come in several different forms: short fibers (also known as staple fibers, or chopped fibers), continuous single fibers (filaments or monofilaments), untwisted bundles of continuous filaments (tows), and twisted bundles of continuous filaments (yarns). Nonwoven fabrics can be formed by a number of processes, including, but not limited to, meltblowing, spunbonding, spunmelt, solvent spinning, electrospinning, carding, film fibrillation, molten film fibrillation, airlaying, drylaying, wetlaying using staple fibers, and combinations of these processes known in the art. The basis weight of nonwoven fabrics is typically expressed in grams per square meter (gsm).

[0061] The term "spunmelt fibers" refers to fibers formed by heating a thermoplastic polymer (e.g., polypropylene, polyester, or nylon) and then extruding the polymer through a metal plate with hundreds of holes known as a spinneret or die. Examples of spunmelt fibers include spunbond and meltblown fibers. Spunmelt fibers can be monocomponent, formed from a single polymer component or a single blend of polymer components; or multicomponent, where the cross-section of each fiber is composed of at least two separate polymer components or blends of polymer components, or at least one separate polymer component and at least one separate blend of polymer components. Fibers having two separate components are sometimes called bicomponent fibers.

[0062] Fabrics or textiles made with spunmelt fibers are sometimes called "spunmelt fabrics or textiles."

[0063] As used herein, the term "spunbond fibers" refers to substantially continuous fibers or filaments having an average diameter in the range of 10 to 30 microns, including splittable bicomponent or multicomponent fibers having an average diameter in the range of 10 to 30 microns before splitting.

[0064] As used herein, the term "meltblown fibers" means substantially continuous fibers or filaments having an average diameter of less than 10 microns.

[0065] The term "fully-calendered nonwoven fabric" as used herein refers to a nonwoven fabric in which the fibers are fused together by melt solidification at adhesive impressions, as known to those skilled in the art. Such fabrics may be converted into various applications themselves, such as diapers, or may be used as precursors for further processing (e.g., hydrophilic spin-finish application or hydraulic treatment). For example, a fully-calendered nonwoven fabric may be produced by passing a batt through a nip point between two heated rolls under pressure, which creates a pattern of melt-embossed impressions in the fabric. The temperature and pressure in the nip are sufficient to soften and melt the individual fibers and then fuse the fibers together with the pattern of protrusions on at least one of the heated rolls to form a series of melt-embossed impressions, where most of the fibers in the melt-bonded impressions are no longer distinguishable as individual fibers. The adhesive impressions fuse the fibers together, or in the case of bicomponent fibers, fuse at least one of the components with the lowest melting temperature throughout the thickness of the fabric. The temperature and pressure of the rolls are adjusted according to the fabric composition and basis weight. For example, 20-25 gsm 100% polypropylene spunbond typically bonds with roll temperatures above 150°C and nip pressures above 90 N / mm. Temperature / pressure settings are adjusted to accommodate various basis weights and / or line speeds. Higher basis weights and / or line speeds may require higher nip pressures and / or temperatures to achieve a "fully" bonded fabric with fusion points. It is understood that temporary bonding is not within the definition of "fully bonded" for purposes of this disclosure.

[0066] As used herein, the term "percentage bonded area" refers to the ratio of the area occupied by adhesive indentations to the total surface area of ​​a nonwoven fabric, expressed as a percentage, and is measured according to the percentage bonded area method described herein.

[0067] "Cross direction" (CD), with respect to the manufacture of nonwoven textile materials and to nonwoven textile materials themselves, refers to the direction along the textile material that is generally perpendicular to the direction of advance of the textile material on the manufacturing line that produces the textile material. With respect to a batt moving through the nip of a pair of calender rollers to form a bonded nonwoven textile, the cross direction is perpendicular to the direction of movement through the nip and parallel to the nip.

[0068] "Machine direction" (MD), with respect to the manufacture of nonwoven textile materials and the nonwoven textile materials themselves, refers to the direction along the textile material that is generally parallel to the direction of advancement of the textile material on the manufacturing line that produces the textile material. With respect to a nonwoven batt moving through the nip of a pair of calender rollers to form a bonded nonwoven textile, the machine direction is parallel to the direction of movement through the nip and perpendicular to the nip.

[0069] A "bonding protrusion" or "protrusion" is a radially outermost feature of a bonding roller surrounded by a concave region. With respect to the axis of rotation of the bonding roller, the bonding protrusion has a radially outermost bonding surface whose bonding surface shape and bonding surface shape area generally follow an outer cylindrical surface with a substantially constant radius from the axis of rotation of the bonding roller; however, multiple protrusions with individual and separate shapes of bonding surfaces are often so small with respect to the radius of the bonding roller that the bonding surface appears flat / planar; the bonding surface shape area closely approximates a planar area of ​​the same shape. The bonding protrusion may have sides perpendicular to the bonding surface, but the sides are usually inclined so that the cross section of the base of the bonding protrusion is larger than the bonding surface. Multiple bonding protrusions may be arranged in a pattern on the calender roller. Multiple bonding protrusions have a bonding area per unit surface area of ​​the outer cylindrical surface, which can be expressed as a percentage, which is the ratio of the sum of the bonding surface areas of the multiple protrusions in a unit to the total surface area of ​​the unit.

[0070] "Adhesive impression" or "fused adhesive impression" in nonwoven fabric refers to the surface structure formed by the impression of adhesive projections on the calendar rollers into the nonwoven fabric. Adhesive impression refers to the portion of molten or heat-sealed material that is deformed, interlocked, or entangled from the overlapping and pressed fibers in the Z direction under the adhesive projections, which form the bond or bond area. In the nonwoven structure, the individual bonds may be connected by loose fibers between the bonds. The shape and dimensions of the adhesive impression approximately correspond to the shape and dimensions of the adhesive surface of the adhesive projections on the calendar rollers. For the purposes of this application, "adhesive impression thickness" is understood to mean the width of the adhesive impression area in the plane of the nonwoven fabric. One or both peripheral surfaces of the rollers may be machined, etched, engraved, or otherwise formed to have an adhesive pattern of adhesive projections and recessed areas thereon, so that the adhesive pressure exerted on the butt at the nip is concentrated at the adhesive surface of the adhesive projections and reduced or nearly absent in the recessed areas. The adhesive surface has an adhesive surface shape. As a result, a fiber-to-fiber bond impression pattern is formed on the nonwoven fabric forming a fabric having bond impressions and bond features corresponding to the pattern of bond projections and bond surface features on the roller. A repeating pattern of bond projections and recessed areas may be formed on the bonding roller. The bond features represent the raised surfaces of the bond projections on the roller and the areas between the raised surfaces represent the recessed areas. The bond features of the bond projections imprint a plurality of similarly shaped bond impressions on the fabric during the calendaring process.

[0071] As used herein, "decrease" of mechanical properties, or tensile strength, abrasion rating, etc., refers to the difference in fabric properties before and after the hydro-patterning process and can be calculated according to the formula [(value of final hydro-patterned fabric property)-(value of precursor property)] / (value of precursor property), where all values ​​are expressed in the same units. The decline can be positive (increase in value during the hydro-patterning process) or negative (decrease in value during the hydro-patterning process) and can be expressed as a ratio (unitless) or a percentage. For example, the decline in MD tensile strength is calculated according to the formula: [(MD tensile strength of final hydro-patterned fabric)-(MD tensile strength of precursor)] / (MD tensile strength of precursor).

[0072] FIG. 1 is a block diagram illustrating various components used in a process for manufacturing a patterned nonwoven textile in accordance with an exemplary embodiment of the present invention. The process illustrated in FIG. 1 results in a nonwoven textile having a spunbond-meltblown-spunbond (SMS) structure (2:3:4), however, it is understood that the process may be reconfigured to form many other textile structures consisting of one or more spunbond layers and / or one or more meltblown layers, such as, for example, textiles having single or multiple spunbond layers. More specific examples include S, SS, SSS, etc.; textiles combining spunbond and meltblown layers, textiles having a spunbond layer that typically forms at least one outer surface of the textile; more specific examples include textiles having asymmetric compositions such as SSMS, SMSSMMS, SSMMS, SMMMSS, etc.; or textiles having symmetric compositions such as SMS, SMMS, SMMMS, SSMSS, etc.; textiles combining spunmelt layers with other layers, more specific examples include textiles having spunmelt layers formed from endless filaments and staple fibers formed from natural materials, etc. Nonwoven textile structures are not limited to the examples provided herein, and one of ordinary skill in the art will understand that many other such structures may be obtained by varying the number and arrangement of process components.

[0073] In general, it is to be understood that the number and configuration of beams are not limited to those shown and described herein, and in other exemplary embodiments, the number and configuration of beams may be varied to achieve different fabric structures. For example, a single spunbond beam may be used to form a nonwoven batt 6 on a conveyor belt 8 with a single spunbond layer, or multiple spunbond beams may be used to form a batt 6 with multiple spunbond layer structures, e.g., SS, SSS, SSSS, etc. The layers formed by the multiple beams may be the same or very similar to each other in terms of filament type, process parameters, etc., so that the multiple layers are nearly indistinguishable from each other, thereby appearing as a single layer structure. Alternatively, the multiple layers may be manufactured differently from each other, thus forming a clearly layered nonwoven product.

[0074] In another exemplary embodiment, only the spunbond beam 2 and the meltblown beam 3 are used to form the nonwoven batt 6 on the conveyor belt 8. According to a further exemplary embodiment of the present invention, multiple elements corresponding to the beams 2 and 3 may be incorporated into the system to form the batt 6 having multiple respective layers, e.g., SM, SMM, SSM, SSMM, etc. Again, the layers formed by the multiple beams may be the same or very similar to each other in terms of filament type, process parameters, etc., so that the multiple layers are nearly indistinguishable from each other, thereby appearing as a single layer structure. Alternatively, the multiple layers may be made different from each other, thus forming a clearly layered nonwoven product.

[0075] According to an exemplary embodiment of the present invention, spunmelt nonwoven batt 6 is produced from continuous filaments laid down on a moving conveyor belt 8 in a random distribution. Resin pellets may be processed under heat into a melt and then fed to spinnerets (or spinning beams 2 and 4) and a drawing device (not shown) may be used to create hundreds of filaments. Multiple spinnerets or beams (blocks in tandem) may be used to densify the spunbond fibers, for example, corresponding to each of spinning beams 2 and 4. The fibers are stretched from beams 2 and 4 by a jet of fluid (such as air) and then blown or conveyed onto a moving fabric (belt conveyor) 8 where they are laid down and sucked against fabric 8 by a suction box (not shown) in a random pattern to form batt 6. Meltblown layers may be accumulated by meltblown mechanism (or "beam") 3, preferably between the spunbond layers laid down by spinning beams 2 and 4. The meltblown ("MB") layer may be formed by a meltblowing process, but may also be formed by a variety of other known processes. For example, the meltblowing process involves inserting a thermoplastic polymer into a die. The thermoplastic polymer material is extruded through a number of fine capillaries in the die to form fibers. The fibers are forced into a high velocity gas (e.g., air) stream that attenuates the flow of molten thermoplastic polymer material, reducing the fiber diameter to microfiber diameter. The meltblown fibers are deposited semi-randomly by beam 3 onto the moving fabric, or onto a moving fabric that has been laid down by spinning beam 2 with a spunbond layer, to form a meltblown layer. To increase fiber coverage, one, two, or more meltblown blocks may be used in tandem. The meltblown fibers can be made tacky as they are deposited, which generally results in some adhesion between the meltblown fibers in the fabric.

[0076] In a preferred embodiment, 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", polyhydroxyalkanoates "PHA", polyhydroxybutyrate "PHB", polybutylene succinate "PBS", or polyethylene terephthalate "PET", etc.), polyamides, polysaccharides (e.g., thermoplastic starch "TPS", or starch-based polymers, etc.), copolymers thereof (with olefins, esters, amides, or other monomers), and blends thereof. Preferably, the fibers are made from polyolefins. Examples of polyolefins include polyethylene, polypropylene, their propylene-butylene copolymers, and blends thereof, such as ethylene / propylene copolymers and polyethylene / polypropylene blends. Resins with high crystallinity and low elongation at break may also be preferred, as they tend to fracture more easily. The fibers may also be formed from non-oily components, such as, for example, aliphatic polyesters, thermoplastic polysaccharides, or other biopolymers, or may contain these materials as additives or modifiers. As used herein, the term "blend" includes a homogeneous or semi-homogeneous mixture of at least two polymers.

[0077] Another approach involves forming nonwoven fabrics of multicomponent, or preferably "bicomponent" polymeric fibers. Such bicomponent polymeric fibers may be formed by a spinneret having two adjacent sections, representing a first component of one polymer or blend and a second component of the other polymer, forming a fiber having a cross section of the first component in one section and the second component in the other section (hence the term "bicomponent"). Advantageously, each component is selected to have a different melting temperature and / or expansion-contraction rate. These different attributes of the two polymers, when combined in an aligned sheath-core or asymmetric sheath-core configuration, may cause the bicomponent fiber product to curve or curl during the spinning process as it cools and is drawn from the spinneret. The resulting crimped fibers may then be laid into a batt and calendered in a pattern. It is believed that the crimping of the fibers provides the fabric with a bumpiness and fuzziness, promoting visual and tactile signs of softness.

[0078] In an exemplary embodiment, the batt 6 may be thermally calendered via rollers 10 and 12. The peripheral surface of one or both of rollers 10 and 12 may be machined, etched, engraved, or otherwise formed with a pattern of protrusions and recessed areas such that the bonding pressure applied to the batt 6 at the nip is concentrated on the outer surface of the protrusions and reduced or nearly eliminated in the recessed areas. According to an exemplary embodiment of the invention, roller 10 is a calender roll and roller 12 is a bonding roll that defines the bonding pattern. The thermal calendering process results in a thermally bonded precursor fabric 7, preferably a fully bonded precursor fabric 7. Preferred bonding patterns according to exemplary embodiments of the invention are further described below.

[0079] According to an exemplary embodiment of the invention, the precursor nonwoven textile 7 is then hydro-treated using one or more water jet injectors. Although three water jets 16a, 16b, and 16c are shown in FIG. 1, it should be understood that the process may use only one injector. One or more injectors are provided in a single water treatment station. According to an exemplary embodiment of the invention, as the precursor nonwoven textile 7 is conveyed by the belt 22 under the injectors 16a-16c, high pressure water jets of the water jets impinge on and pass through the fabric. Again, although three water jets are shown in FIG. 1, it should be understood that the number of water jets is not limited to three and any number and arrangement of water jets may be provided on a particular line as appropriate. In an exemplary embodiment, it is possible to provide one or more water jets, preferably 2-6 water jets, more preferably 3-4 water jets.

[0080] Below the location of each jetting device (set) 16a-16c, a corresponding water removal system 20a, 20b, and 20c may be positioned to suck and remove the water and dry the precursor fabric 7. The water removal systems 20a, 20b, and 20c may be equipped with, for example, vacuum boxes, suction boxes, Uhle boxes, fans, and / or vacuum slots. The nonwoven precursor fabric 7 may then be dried by blowing hot air through the fibrous fabric, using an infrared (IR) dryer, or other drying techniques (e.g., air drying).

[0081] In accordance with an exemplary embodiment of the present invention, belt 22 incorporates one or more screens, each having a predetermined pattern for supporting precursor nonwoven fabric 7 during hydrostatic treatment by a respective water jet 16a-16c. As will be described in more detail below with reference to Figures 2A and 2B, one or more screens may be substituted for one or more drums 14, with one drum, or the last drum in the series of drums, being provided with a sleeve 18.

[0082] According to an exemplary embodiment of the present invention, water injection is multiple steps by using one or more drums, each connected to one or more water injection devices. The desired water pressure at each step depends on many parameters such as the number of water injection steps and the line speed. In general, the more water injection steps utilized in a process, the lower the pressure required at each step to achieve the desired fabric properties. In other words, the energy flux obtained by multiple water injection devices each applying a certain amount of water pressure can also be obtained by increasing the number of water injection devices and decreasing the water pressure applied by each injection device. The desired water pressure at each step also depends, at least in part, on the line speed. The faster the line speed, the higher the pressure required to maintain a constant flux. In other words, the energy flux obtained by line speed and injection device pressure can also be obtained by reducing both the line speed and the injection device pressure.

[0083] Without being bound by theory, it is believed that the preferred total water jet pressure applied to precursor fabric 7 may be expressed in terms of energy flux. According to an exemplary embodiment, the preferred energy flux applied to precursor fabric 7 is in the range of 0.1-1.5 kWh / kg, preferably in the range of 0.2-1.0 kWh / kg. For example, the desired energy flux may be obtained by varying the machine speed and / or water pressure at each water jet. The desired energy flux is preferably achieved by using one or more water jets at a relatively low pressure, rather than by reducing the number of water jets at a higher pressure. The energy flux is calculated using the following formula: Flux = ((J^1.5)*(G^2)*(I)*(L / 1000)*(7 / 100000000000)) / F: Therefore TIFF2024516027000002.tif20137J=Water pressure (bar) G = jet zone hole diameter (microns) I = number of holes / length of jet zone (m) L = width of nonwoven fabric (m) F = nonwoven mass flow rate (i.e., nonwoven fabric throughput calculated based on line speed, product width, and basis weight) (kg / hr)

[0084] In a preferred exemplary embodiment of the present invention, a relatively large number of water jets are used. Without being bound by theory, this allows for higher line speeds without the need for increased water pressure. Figures 2A and 2B show an exemplary embodiment of the present invention employing one or more drums for imparting a pattern to the nonwoven fabric. Similar elements are numbered the same as in Figure 1.

[0085] Without being bound by theory, it is believed that the properties of the precursor nonwoven textile have a strong influence on the characteristics of the final textile. In this regard, hydropatterned textiles according to exemplary embodiments of the present invention are subjectively pleasing in both visual appearance and tactile feel. The process of the present invention results in a nonwoven textile with an enhanced pattern of adhesive impressions on the precursor, such that the final nonwoven product may appear to have a 3D pattern even without 3D shaping during the hydrotreatment step. Combining a suitable precursor pattern enhances the 3D effect, providing additional benefits such as improved tactile properties and increased thickness while maintaining the same basis weight, as well as performance benefits such as space for liquid management control. At the same time, the thermally bonded, preferably fully bonded, precursor provides the necessary mechanical properties for the textile, such as strength, elongation, and abrasion resistance.

[0086] The precursor nonwoven fabric is subjected to a hydropatterning process as described herein to provide desirable improvements in pattern visual effects, thickness, and softness with limited degradation in mechanical properties such as, for example, tensile strength, elongation, or abrasion resistance. Important features of the precursor nonwoven fabric according to exemplary embodiments of the present invention are described below.

[0087] The prior art, particularly U.S. Patent No. 7,858,544 and related applications, describes the advantages of using elliptical and so-called anisotropic patterned adhesive impressions (fusion bonds), but the advantages are limited to only a percentage of the total bonded area. Surprisingly, it has been found that non-anisotropic patterns of adhesive impressions are well suited to the hydropatterning process disclosed herein and provide the desired visual effect.

[0088] In an exemplary embodiment, the precursor nonwoven fabric may have a bonded area percentage of at least 5%, preferably at least 10%. Without being bound by theory, it is believed that a lower bonded area percentage does not provide sufficient stability to the batt, causing the fabric to become unstable during the hydropatterning process.

[0089] In an exemplary embodiment, the maximum bonded area percentage of the precursor nonwoven fabric may be preferably 30%, preferably 25%. Without being bound by theory, it is believed that a higher bonded area percentage would result in an excessively large area of ​​fusion imprints, which, while not damaging the bond imprints, would not provide enough space for the water flow to interact with the textile filaments, thereby significantly reducing the mechanical properties of the final textile fabric compared to the precursor.

[0090] In addition to the percentage of bonded area, the size and shape of the bonded indentations, as well as the distance between the bonded indentations, are important parameters in the whole hydropatterning process.

[0091] Generally, there are two groups of adhesive indentations: adhesive indentation area of ​​1 mm 2 "Small diameter adhesive indentation" less than 1 mm 2 The dimensions of the adhesive impression are generally provided by the calendar manufacturer, but can also be measured on the precursor or estimated from the hydropatterned fabric. When measuring from the fabric, the same method used to determine the percentage adhesive area is used to measure at least 20 single adhesive impressions in each type of fabric, and the arithmetic mean value is calculated.

[0092] The small diameter-like adhesive indentations are typically arranged in a regular pattern with rows and columns, or formed in a linear or other various shapes. For the purposes of this disclosure, adjacent small diameter-like adhesive indentations are considered to be individual adhesive indentations if the minimum distance between adjacent adhesive indentations is at least 0.3 mm, preferably at least 0.4 mm, and most preferably at least 0.5 mm.

[0093] According to an exemplary embodiment of the present invention, 1 cm of fabric 2 The number of small diameter-like adhesive impressions per square centimeter is at least 20 per square centimeter, preferably at least 30 per square centimeter, more preferably at least 40 per square centimeter, more preferably at least 50 per square centimeter, and even more preferably at least 60 per square centimeter.

[0094] The large-diameter-like adhesive impressions can also be arranged in a regular pattern with rows and columns, and the features are large enough to be clearly visible to the naked eye on the thermally bonded fabric. The adhesive pattern may be formed by repeating one feature many times, or by combining one or more large-diameter-like adhesive features.

[0095] It is also possible to combine large and small adhesive impressions, as described, for example, in EP 3 452 652.

[0096] Examples of various patterns formed from small-diameter-like adhesive indentations, large-diameter-like adhesive indentations, and combinations of small-diameter-like adhesive indentations and large-diameter-like adhesive indentations are shown in the figures and described below.

[0097] Without being bound by theory, it is believed that the presence of small-diameter-like adhesive indentations is advantageous in the hydropatterning process because the small-diameter-like adhesive indentations have a small area and the amount of fused filaments in each indentation is small, so the indentations are slightly mobile within the fabric. When the water flow is about to hit the small-diameter-like adhesive indentations, the adhesive indentations can move slightly in any direction and can even tilt in the Z direction, thus avoiding the full energy from the water flow and limiting the possible resulting damage. Without being bound by theory, it is believed that the presence of small-diameter-like adhesive indentations reduces the degradation of the mechanical properties of the fabric during the hydropatterning process.

[0098] Large-diameter-like adhesive indentations with carefully selected indentation shapes are also suitable for use in exemplary embodiments of the present invention, as they are free to move / tilt and avoid receiving the full energy from the water flow.

[0099] Without being bound by theory, it is believed that large diameter-like adhesive indentations having a linear shape that is straight or contoured or curved and of constant or irregular width are advantageous for use in the hydropatterning process according to exemplary embodiments of the present invention in that such adhesive indentations minimize degradation of the mechanical properties of the fabric during the hydropatterning process.

[0100] In an exemplary embodiment, the linear large-diameter-like adhesive indentations are in the form of a continuous line with a line width (W) of at most 0.6 mm, preferably at most 0.5 mm, most preferably at most 0.4 mm. The linear large-diameter-like adhesive indentations are preferably not continuous with each other. In an exemplary embodiment, the maximum line length (L) of the linear large-diameter-like adhesive indentations is 30 mm, preferably 25 mm, more preferably 20 mm.

[0101] Figures 3A, 3B, 3C, and 3D show various preferred linear bond patterns for use in accordance with exemplary embodiments of the present invention. Figure 3A shows a pattern formed with straight lines of constant width, where the straight lines making up each individual impression are not continuous with one another. Figure 3B shows a pattern formed with curved lines of constant width, where the curved lines making up each individual impression are not continuous with one another. Figures 3C and 3D show patterns formed with curved lines of irregular width, where the curved lines are continuous with one another. Figure 3C shows a continuous pattern on a precursor fabric, and Figure 3D shows a continuous pattern on a hydropatterned fabric.

[0102] For purposes of this disclosure, the length L of the adhesive impression is measured by identifying the shape length line that intersects the perimeter of the adhesive shape at the intersection point that is the greatest distance apart that can be identified on the perimeter, i.e., the distance between the two furthest points on the perimeter. As reflected in Figures 3A and 3B, the adhesive shape has a width W, which is measured by identifying each shape width line that is tangent to the shape perimeter at one or more outermost points that are furthest from the shape length lines on both sides and parallel to the shape length lines. It is understood that for some shapes (e.g., semicircles), one of the shape width lines may be coincident / collinear with the shape length line. Width W is the distance between the shape width lines.

[0103] Without being bound by theory, it is believed that the linear large-diameter-like adhesive indentations are more advantageous in avoiding mechanical damage during the hydropatterning process when oriented approximately in the MD direction. The linear adhesive indentations may be oblique to the MD direction, such that the feature inclination angle αT is expressed as the smaller of the angles formed by the intersection of the axis along the machine direction with the feature length line. The feature inclination angle αT is preferably 50 degrees or less, more preferably 40 degrees or less, even more preferably 30 degrees or less, and most preferably 20 degrees or less.

[0104] Without being bound by theory, it is believed that the linear large-diameter-like adhesive indentation is more advantageous in avoiding mechanical damage during the hydro-patterning process when the adhesive indentation shape includes at least one protrusion along the periphery of the indentation. For example, the linear large-diameter-like adhesive indentation may have a protrusion along the periphery of the indentation to present a C-shape, a circular shape, or a J-shape. For example, the linear large-diameter-like adhesive indentation may have two protrusions to present an S-shape, a B-shape, an 8-shape, etc.

[0105] The distance between the adhesive indentations, in other words the area of ​​unbonded filaments between the adhesive indentations, provides space that can absorb the energy from the water stream, resulting in an increase in the thickness and softness of the fabric compared to the precursor fabric. During the fabric forming process, free filaments are laid on a belt to form a batt, and defined areas within the batt are fused to form adhesive indentations. Usually, one filament extends through many adhesive indentations. Importantly, the path of the filament is not a straight line, but instead forms various loops and bends throughout three dimensions, which are mostly in the MD-CD plane. The water stream energy of the subsequent hydropatterning process moves the free parts of the filaments, strengthening the path of the filaments in three dimensions (across the thickness of the fabric). As a result, the thickness of the fabric increases. Hydropatterning also smooths or loosens the stiff edges of the adhesive indentations (formed by the protrusions on the calender rolls and oriented along the fabric surface), improving the tactile properties of the fabric. Therefore, the hydropatterned fabric according to the exemplary embodiment of the present invention is very comfortable to the touch and feels pleasant to the touch when worn. Furthermore, changing the orientation of the free portions of the filaments changes the visual effect of the fabric. For example, such a change may enhance the pattern or parts of the pattern, making even a flat fabric perceivable in 3D. To enhance this desired effect, it is preferable to have some areas of the shape and size of the filaments that are not bonded.

[0106] Without being bound by theory, it is believed that increasing the size of the free filament area unencumbered by the adhesive marks enhances the desired effect of the hydropatterning process. In this regard, the size of the free filament area in the adhesive pattern may be measured by defining a maximum imaginary circle C, which has a perimeter that encompasses the free filament area and passes through a point on the perimeter of each of at least two adhesive impressions in the pattern. Here, the size of the free filament area is defined as the radius of the imaginary circle. Figures 4A, 5, 6A, 7A, 7B, 8A, 9, 10A, and 10B show circles C defined in various adhesive patterns in accordance with exemplary embodiments of the present invention.

[0107] In an exemplary embodiment, the radius of circle C is at least 0.5 mm, preferably at least 1 mm, more preferably at least 1.5 mm, and even more preferably at least 2 mm.

[0108] Without being bound by theory, it is believed that the non-linear shape of the adhesive indentation provides an advantage when combined with small diameter-like indentations and / or free filament regions. Such adhesive indentations may have a non-linear shape, such as, for example, a circle, ellipse, diamond, square, rectangle, etc., and do not have a discernible width W or length L as described above. For purposes of this disclosure, non-linear adhesive indentations or linear adhesive indentations having a width of at least 0.6 mm are referred to as large diameter-like adhesive indentations.

[0109] In an exemplary embodiment, various pattern features may be combined to provide synergistic benefits to the benefits provided by the hydro-pattern treatment process. Table 1 shows various pattern features that may be used in a process according to an exemplary embodiment of the present invention.

[0110] For example, the reference pattern P1 (FIGS. 4A and 4B) consists of small-diameter-like adhesive indentations arranged in rows and columns forming a regular pattern. In this pattern, the radius of the circle C is less than 0.5 mm and does not include large-diameter-like adhesive indentations. With this reference pattern, it can be expected that the deterioration of the mechanical properties will be relatively small, but the thickness will not increase significantly.

[0111] In an exemplary embodiment, small diameter-like adhesive indentations may be arranged around the free filament region to achieve a desired effect. For example, small diameter-like adhesive indentations may be arranged directly adjacent to one another to form lines like a stone path on a lawn. Such a pattern is designated P6 and is shown in FIG. 5. In this case, the water flow / pressure treatment results in only a slight decrease in mechanical properties and a large increase in fabric thickness.

[0112] In an exemplary embodiment, the pattern of adhesive impressions has a bond area of ​​1 mm 2and the minimum distance between adjacent adhesive indentations is at least 0.3 mm, preferably at least 0.4 mm, and most preferably at least 0.5 mm, and in this pattern the radius of circle C is at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm, and even more preferably at least 4 mm.

[0113] In an exemplary embodiment, the large-diameter-like adhesive indentations may be arranged around the free filament region to achieve a desired effect. For example, elliptical large-diameter-like adhesive indentations may be arranged such that the free filament region separates the large-diameter-like adhesive indentations. Figures 6A and 6B show such a pattern, designated P2, in Figures 6A and 6B. In this case, the mechanical properties of the large-diameter-like adhesive indentations are greatly reduced, but the fabric thickness in the free filament region is increased.

[0114] In an exemplary embodiment, the pattern of adhesive impressions has a bonded area of ​​at least 1 mm 2 The radius of circle C is at least 0.5 mm, preferably at least 1.0 mm, more preferably at least 1.5 mm, and even more preferably at least 2.0 mm.

[0115] In an exemplary embodiment, the pattern of adhesive impressions has a bonded area of ​​at least 1 mm 2 The radius of circle C is at least 0.5 mm, preferably at least 1.5 mm, and more preferably at least 2.0 mm.

[0116] In an exemplary embodiment, the linear large-diameter-like adhesive indentations may be arranged around the free filament region to achieve a desired effect. For example, the linear large-diameter-like adhesive indentations may consist of a series of curved lines that cross each other to form the free filament region. Such a pattern is designated P7 and is shown in Figures 7A and 7B. In this case, the mechanical properties of the linear large-diameter-like adhesive indentations are not significantly reduced, and the fabric thickness in the free filament region is increased.

[0117] In an exemplary embodiment, the pattern of adhesive indentations consists of linear large-diameter-like adhesive indentations with a maximum line width (W) of 0.6 mm, preferably 0.5 mm, and most preferably 0.4 mm, and the radius of the circle C is at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm, and even more preferably at least 4 mm. The perimeter of the linear adhesive indentations preferably includes at least one protrusion.

[0118] In an exemplary embodiment, discontinuous linear large-diameter-like adhesive indentations may be arranged around the free filament region to achieve a desired effect. For example, the linear large-diameter-like adhesive indentations may be I-shaped or S-shaped, where the adhesive indentations are arranged in rows and columns. Such a pattern is designated P3 and is shown in Figures 8A and 8B. In this case, the mechanical properties of the linear discontinuous large-diameter-like adhesive indentations are not significantly reduced, and the fabric thickness in the free filament region is increased.

[0119] In an exemplary embodiment, the pattern of adhesive indentations consists of linear large-diameter-like adhesive indentations with a maximum line width (W) of 0.6 mm, preferably 0.5 mm, most preferably 0.4 mm, the maximum length (L) of said linear large-diameter-like adhesive indentations is 30 mm, preferably 25 mm, more preferably 20 mm, and the radius of circle C is at least 0.5 mm, preferably at least 1.0 mm, more preferably at least 1.5 mm, even more preferably at least 2.0 mm. The perimeter of the linear adhesive indentations preferably includes at least one protrusion.

[0120] In an exemplary embodiment, the large-diameter-like adhesive indentations and the small-diameter-like adhesive indentations may be arranged around the free filament area to achieve a desired effect. For example, the circular large-diameter-like adhesive indentations are arranged relatively far apart, and the small-diameter-like adhesive indentations form connecting lines between some of the large-diameter-like adhesive indentations, thereby forming free filament areas between the large-diameter-like adhesive indentations and the small-diameter-like adhesive indentations. Such a pattern is designated P9 and is shown in FIG. 9. In this case, the synergistic effect of the described combination results in a significant increase in thickness and visual effect, with a slight decrease in mechanical properties. For example, the hydropatterning process visually emphasizes the large-diameter-like adhesive indentations and visually suppresses the small-diameter-like adhesive indentations, thereby providing an overall soft and fluffy cushion-like visual effect with improved mechanical properties and wear evaluation properties.

[0121] In an exemplary embodiment, the pattern of adhesive impressions has a bonded area of ​​at least 1 mm 2 The adhesive indentation is large and the adhesive area is 1 mm 2 and the radius of circle C is at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm, and even more preferably at least 4 mm.

[0122] In an exemplary embodiment, discontinuous linear large-diameter-like adhesive indentations and small-diameter-like adhesive indentations may be arranged around the free filament region. For example, discontinuous linear large-diameter-like adhesive indentations may be used to form a visually dominant pattern (e.g., a sun-shaped pattern) that is spaced relatively far apart from each other, with various small-diameter-like adhesive indentations arranged between the visually dominant patterns. Such a pattern is designated P8 and is shown in Figures 10A and 10B. In this case, the synergistic effect of the described combination results in a significant increase in thickness and visual effect, with a slight decrease in mechanical properties. For example, the hydropatterning process visually emphasizes the visually dominant pattern and visually suppresses the small-diameter-like adhesive, thereby providing an overall soft and fluffy visual effect with improved mechanical and wear evaluation properties.

[0123] In an exemplary embodiment, the pattern of adhesive indentations is a line-shaped large diameter-like adhesive indentation having a maximum line width (W) of 0.6 mm, preferably 0.5 mm, and most preferably 0.4 mm, a maximum length (L) of 30 mm, preferably 25 mm, and more preferably 20 mm, and an adhesive area of ​​1 mm 2 The radius of the circle C is at least 1 mm, preferably at least 2 mm, more preferably at least 3 mm, and even more preferably at least 4 mm. The outer periphery of the linear adhesive impression preferably includes at least one convex portion.

[0124] It is to be understood that the present invention is not limited to the patterns described herein, and exemplary embodiments may include various other combinations of patterns to achieve the desired effect of the hydro-patterning process.

[0125] Without being bound by theory, it is believed that Equation 1 can be used to predict suitable thermal bond patterns for the hydropatterning process. TIFF2024516027000003.tif47136K=[(1cm 2 (Number of adhesive impressions per unit area)*100) / [(Adhesive area percentage (%))*(Minimum adhesive impression area in pattern (mm 2 ))*(area of ​​the largest possible circle C (mm 2 )) Equation 1 cannot be applied to patterns that contain continuous linear large-diameter-like adhesive indentations.

[0126] Without being bound by theory, it is believed that a K value greater than 5 is desirable for the hydropatterning process. At K values ​​greater than 20, the fabric exhibits an increase in thickness during the hydropatterning process, and at K values ​​greater than 50, the hydropatterned fabric exhibits a significant improvement in visual properties without a significant decrease in mechanical properties. It should be noted that all K values ​​above a certain threshold, e.g., 100, may be equivalent or similar in quality, so a K value of, e.g., 200 is not necessarily better than a K value of 150.

[0127] In an exemplary embodiment, the K value is at least 5, preferably at least 10, more preferably at least 15, even more preferably at least 25, and most preferably at least 50. Properties of adhesive patterns that can be used in a hydropatterning process according to an exemplary embodiment of the present invention are shown in Table 1 of FIG.

[0128] Hydropatterned fabrics according to exemplary embodiments of the present invention produced by the processes described herein are soft, have good tactile properties, and are comfortable to wear.

[0129] According to an exemplary embodiment, the CD tensile strength loss is less than 50%, preferably less than 40%, more preferably less than 30%, and most preferably less than 20%.

[0130] According to an exemplary embodiment, the tensile strength loss in the MD is less than 50%, preferably less than 40%, more preferably less than 30%, and most preferably less than 20%.

[0131] According to an exemplary embodiment, the hydro-patterned nonwoven fabric has a basis weight of 10 gsm to 60 gsm, preferably 15 gsm to 45 gsm, and most preferably 20 gsm to 35 gsm.

[0132] According to an exemplary embodiment, the caliper of the hydropatterned nonwoven fabric is at least 10 microns / gsm of fabric, preferably at least 11 microns / gsm of fabric, and most preferably at least 12 microns / gsm of fabric.

[0133] According to an exemplary embodiment, the hydropatterned nonwoven fabric has a MD tensile strength of at least 4 N / cm.

[0134] According to an exemplary embodiment, the hydropatterned nonwoven fabric has a CD tensile strength of at least 2 N / cm.

[0135] According to an exemplary embodiment, the hydro-patterned nonwoven fabric provides a high level of softness. Softness itself is a very general term that encompasses many different perceptions, some of which may be expressed by measurements such as Handle-O-meter, cantilever testing, compressibility, thickness, coefficient of friction, and / or many other methods. It should be noted that each test provides only limited information regarding softness and may only be suitable for some applications or for some ranges of basis weights, polymer compositions, etc.

[0136] The nonwoven fabric may be incorporated into a nonwoven laminate. The nonwoven laminate may include additional layers of continuous fibers, such as spunbond or meltblown fibers, or may include composite nonwovens, such as spunbond-meltblown-spunbond laminates. The nonwoven laminate may also include short fibers, such as staple fibers, or pulp fibers. These short fibers may be in the form of consolidated fabrics, such as worsted fabrics or tissue sheets, or may not be natively consolidated. The nonwoven laminate may include superabsorbent material in either particulate or fiberized form. The laminate may be formed by conventional means, such as, but not limited to, thermal bonding, ultrasonic bonding, chemical bonding, adhesive bonding, and / or hydroentanglement. According to an exemplary embodiment of the present invention, the fabric may form a nonwoven laminate resulting from one or more of the processes described above for use as a topsheet, absorbent core, or backsheet of an absorbent article.

[0137] In other exemplary embodiments of the invention, the screen or roll sleeve may not be flat, but may instead include a 3D shape to be imparted to the fabric. In an exemplary embodiment using a series of drums, the 3D screen may be used only on the last drum in the process line to generally shape the precursor fabric. In this regard, the drum before the last drum in the process line preferably does not include a 3D screen, but may instead include a mesh screen. In an exemplary embodiment, the drums up to the penultimate drum in the line of drums may be used to prepare the precursor fabric for 3D shaping, although again, the actual shaping of the precursor fabric is preferably performed on the last drum. It should be understood that in other exemplary embodiments of the invention, the 3D screen may be provided on a belt rather than on a drum.

[0138] In an exemplary embodiment, the multiple steps of water jetting include subjecting the thermally bonded nonwoven precursor fabric 7 to multiple water jet devices (each water jet device having a set of jets / nozzles), each water jet device applying a higher water pressure in the machine direction than the water jet device immediately preceding it. For example, water jet device 16c may apply a higher water pressure than water jet device 16b, which in turn may apply a higher water pressure than water jet device 16a. In a specific exemplary embodiment, water jet device 16b applies a water pressure that is at least 80%, preferably 80%-95% of the water pressure applied by water jet device 16c, and water jet device 16a applies a water pressure that is at least 80%, preferably 80%-95% of the water pressure applied by water jet device 16b. In an embodiment, water jet 16a applies a water pressure of at least 64%, preferably 64%-90% of the water pressure applied by water jet 16c, to desirably improve the visual effect, thickness, and softness of the pattern, and to limit the degradation of mechanical properties, such as tensile strength, elongation, and abrasion resistance. Water jet 16a applies a relatively low water pressure to initially soften the precursor fabric, and water jets 16b and 16c apply a relatively high water pressure to improve the thickness and the desired visual effect. Without being bound by theory, it is believed that the increasing gradient of the applied water pressure helps to retain the individual adhesive impressions during the softening and thickening stages, so as to minimize the degradation of mechanical properties, such as tensile strength, elongation, or abrasion resistance.

[0139] In an embodiment, the multiple steps of water jetting include subjecting the thermally bonded nonwoven precursor fabric 7 to two water jet devices (each water jet device having a set of jets / nozzles), each water jet device applying a higher water pressure in the machine direction than the previous water jet device. For example, water jet device 16c may apply a higher water pressure than water jet device 16b, and water jet device 16a may be excluded.

[0140] In an embodiment, the multiple water jetting steps include subjecting the thermally bonded nonwoven precursor fabric 7 to four or more water jet devices (each water jet device having a set of jets / nozzles), each water jet device applying a higher water pressure in the machine direction than the water jet device immediately preceding it.

[0141] In an exemplary embodiment, the water pressure treatment alters at least a portion of the individual adhesive impressions by applying water pressure, in that the application of water pressure removes at least a portion of the fully bonded portions of the individual adhesive impressions, such that at least 60%, preferably at least 70%, more preferably 80%, and even more preferably 90% of the fully bonded portions of the individual adhesive impressions remain after the step of applying water pressure.

[0142] In an embodiment, the application of water pressure may separate the individual adhesive indentations into at least two parts. In an embodiment, the application of water pressure may reduce the overall dimensions of the individual adhesive indentations while maintaining their general characteristics. For example, as shown in Figures 16A and 16B, the change may reduce the dimensions of the adhesive indentations while maintaining their general characteristics. Without being bound by theory, it is believed that the at least partial change of the individual adhesive indentations improves the tactile softness without significantly decreasing the tensile strength and / or wear resistance of the final product. Tactile softness is a complex value that is difficult to express by simple measurements in the way that a human finger expresses the sensation. The values ​​measured in this application (caliper, handle-o-meter (HOM), coefficient of friction (COF)) are partial measurements of tactile softness and do not represent tactile softness in a complex manner.

[0143] In an embodiment, as shown in Figures 15A-15F, application of water pressure causes fibers in the area around the periphery of each adhesive impression to randomly fray in and out of the main plane of the fully bonded precursor nonwoven fabric, and at least partially removes the natural reinforcing fibers around the periphery of the adhesive impression, so that at least some of the individual adhesive impressions are no longer three-dimensional. More specifically, Figure 15A is a cross-sectional view showing the formation of individual adhesive impressions by patterned calender rolls 12 and smooth calender 10 with natural reinforcing fibers at the edges of the adhesive impressions, Figure 15B is a cross-sectional view of a bonded precursor fabric with individual adhesive impressions 100 and natural reinforcing fibers at the edges of the adhesive impressions, and Figure 15C is a cross-sectional view of a water pressure treated nonwoven fabric with altered individual adhesive impressions, in which the edges of the adhesive impressions are free of natural reinforcing fibers and the adhesive impressions themselves are somewhat smaller. Figure 15D is a cross-sectional photomicrograph of an individual modified adhesive imprint according to an exemplary embodiment of the present invention, showing how hydraulic treatment has caused the edges to fray around the perimeter of the adhesive imprint, resulting in a lack of natural reinforcing fibers around the perimeter of the adhesive imprint. In contrast, Figures 15E and 15F are cross-sectional photomicrographs of a conventional precursor adhesive imprint, as shown in U.S. Patent No. 8,410,007, in which the natural reinforcing fibers are clearly visible.

[0144] Without being bound by theory, it is believed that the randomization of fibers around the perimeter of each adhesive impression results in a softer final product (tactile softness).

[0145] The following examples and comparative examples illustrate the advantages of the present invention.

[0146] Comparative Example 1 (Precursor Fabric of Example 1) A 25 gsm spunmelt nonwoven batt was produced on-line in a continuous process from a mixture of polypropylene (type 3155E5, Exxon) and copolymer (Vistamaxx 6202, Exxon) in a weight ratio of 80:10, and a flexibility-promoting additive based on erucamide (CESA-slip PP 42161, Avient). Here, monocomponent polypropylene filaments with fiber diameters of 13-25 μm were produced and then collected on a moving belt. The batt was produced with REICOFIL 3.1 technology (Reifenhauser Reicofil, Troisdorf, Germany) from four spunbond beams. The nonwoven batt was completely bonded by a pair of heated rollers, where one roller had a raised pattern P2 (Figures 6A, 6B). The temperatures of the calendar rollers (smooth roller / pattern roller) were 160°C / 156°C and the bonding pressure was 110 N / mm. The resulting nonwoven fabric was considered to be completely unbonded and had the material properties shown in Tables 2 and 3.

[0147] Example 1 The same nonwoven fabric as described in Comparative Example 1 was formed, but with the addition of a hydropatterning step. The hydropatterning was performed using two drums with the same setup (one wire mesh screen and two jets on each drum, each jet had a water pressure of 125 bar). Each jet had two rows of holes, each row of holes spaced 0.6 mm apart from each other (type 2j12). The fabric travel speed was 300 m / min. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0148] Comparative Example 2 (Precursor Fabric of Example 2) A 25 gsm spunmelt nonwoven batt was produced on-line in a continuous process from a mixture of polypropylene (type 3155E5, Exxon) and copolymer (Vistamaxx 6202, Exxon) in a weight ratio of 80:10, and a flexibility-promoting additive based on erucamide (CESA-slip PP 42161, Avient). Here, monocomponent polypropylene filaments with fiber diameters of 13-25 μm were produced and then collected on a moving belt. The batt was produced with REICOFIL 3.1 technology (Reifenhauser Reicofil, Troisdorf, Germany) from four spunbond beams. The nonwoven batt was completely bonded by a pair of heated rollers, where one roller had a raised pattern P2 (Figures 6A, 6B). The temperatures of the calendar rollers (smooth roller / pattern roller) were 163°C / 161°C and the bonding pressure was 130 N / mm. The resulting nonwoven fabric was considered to be fully bonded and had the material properties shown in Tables 2 and 3.

[0149] Example 2 The same nonwoven fabric as described in Comparative Example 2 was formed, but with the addition of a hydropatterning step. The hydropatterning was performed using two drums with the same setup (one wire mesh screen and two jets on each drum, each jet had a water pressure of 125 bar). Each jet had two rows of holes, each row of holes spaced 0.6 mm apart from each other (type 2j12). The fabric travel speed was 300 m / min. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0150] Comparative Example 3 (Precursor Fabric of Example 3) A 25 gsm spunmelt nonwoven batt was produced on-line in a continuous process from a mixture of polypropylene (type 3155E5, Exxon) and copolymer (Vistamaxx 6202, Exxon) in a weight ratio of 75:15, and a softness-promoting additive based on erucamide (CESA-slip PP 42161, Avient). Here, monocomponent polypropylene filaments with fiber diameters of 13-25 μm were produced and then collected on a moving belt. The batt was produced with REICOFIL 3.1 technology (Reifenhauser Reicofil, Troisdorf, Germany) from four spunbond beams. The nonwoven batt was completely bonded by a pair of heated rollers, where one roller had a raised pattern P3 (Figures 8A, 8B). The temperatures of the calendar rollers (smooth roller / pattern roller) were 160°C / 163°C and the bonding pressure was 130 N / mm. The resulting nonwoven fabric was considered to be fully bonded and had the material properties shown in Tables 2 and 3.

[0151] Example 3 The same nonwoven fabric as described in Comparative Example 3 was formed, but with the addition of a hydropatterning step. The hydropatterning was performed using two drums with the same setup (one wire mesh screen and two jets on each drum, each jet had a water pressure of 125 bar). Each jet had two rows of holes, each row of holes spaced 0.6 mm apart from each other (type 2j12). The fabric travel speed was 300 m / min. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0152] Comparative Example 4 (Precursor Fabric of Example 4) A 25 gsm spunmelt nonwoven batt was produced on a production line in a continuous process from a mixture of polypropylene (type 3155E5, Exxon), a low molecular weight additive (L-MODU, Idemitu Kosan), and a softness-promoting additive based on erucamide (CESA-slip PP 42161, Avient). Here, monocomponent polypropylene filaments with fiber diameters of 13-25 μm were produced and then collected on a moving belt. The batt was produced with REICOFIL 3.1 technology (Reifenhauser Reicofil, Troisdorf, Germany) from four spunbond beams. The nonwoven batt was completely bonded by a pair of heated rollers, where one roller had a raised pattern P7 (Figure 7A, Figure 7B). The temperature of the calender rollers (smooth roller / pattern roller) was 160 °C / 165 °C, and the bonding pressure was 110 N / mm. The resulting nonwoven fabric was considered to be fully bonded and had the material properties shown in Tables 2 and 3.

[0153] Example 4 The same nonwoven fabric as described in Comparative Example 4 was formed, but with the addition of a hydropatterning step. The hydropatterning was performed using two drums with the same setup (one wire mesh screen and two jets on each drum, each jet had a water pressure of 125 bar). Each jet had two rows of holes, each row of holes spaced 0.6 mm apart from each other (type 2j12). The fabric travel speed was 300 m / min. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0154] Comparative Example 5 (Precursor Fabric of Example 5) A 25 gsm spunmelt nonwoven batt was produced on a production line in a continuous process from a mixture of polypropylene (Mosten NB425, Unipetrol) and copolymer (Vistamaxx 6202, Exxon) in a weight ratio of 95:5, a color additive (SCC91056, Standridge Color), and a softness-promoting additive based on erucamide (CESA-slip PP 42161, Avient). Here, monocomponent polypropylene filaments with fiber diameters of 13-25 μm were produced and then collected on a moving belt. The batt was produced with REICOFIL 3.1 technology from four beams. The nonwoven batt was completely bonded by a pair of heated rollers, where one roller had a raised pattern P5 (Figure 9). The temperature of the calender rollers (smooth roller / pattern roller) was 162°C / 162°C, and the bonding pressure was 105 N / mm. The resulting nonwoven fabric was considered to be fully bonded and had the material properties shown in Tables 2 and 3.

[0155] Example 5 The same nonwoven fabric as described in Comparative Example 5 was formed, but with the addition of a hydropatterning step. The hydropatterning was performed using two drums with the same setup (one wire mesh screen and two jets on each drum, each jet had a water pressure of 125 bar). Each jet had two rows of holes, each row of holes spaced 0.6 mm apart from each other (type 2j12). The fabric travel speed was 300 m / min. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0156] Comparative Example 6 (Precursor Fabric of Example 6) A 35 gsm spunmelt nonwoven batt was produced on a production line in a continuous process from a mixture of polypropylene (type 3155E5, Exxon) and color additive (SCC91056, Standridge Color). Here, monocomponent polypropylene filaments with fiber diameters of 13-25 μm were produced and then collected on a moving belt. The batt was produced with REICOFIL5 technology from three spunbond beams. The nonwoven batt was completely bonded by a pair of heated rollers, where one roller had a raised pattern P6 (Figure 5). The temperature of the calender rollers (smooth roller / pattern roller) was 160°C / 162°C and the bonding pressure was 75 N / mm. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0157] Example 6 The same nonwoven fabric as described in Comparative Example 6 was formed, but with the addition of a hydropatterning step. The hydropatterning was performed using two drums. The first drum had a wire mesh screen and one jet disposed on the drum applying a water pressure of 80 bar, the one jet on the first drum having two rows of holes, the holes in each band spaced 1.2 mm apart from each other. The second drum had a micro-porous shell screen (MPC screen) and three jets applying water pressures of 90 bar, 90 bar, and 150 bar, respectively. Each of the three jets on the second drum had two bands of holes, the holes in each band spaced 0.6 mm apart from each other. The travel speed of the nonwoven fabric was 100 m / min. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0158] Comparative Example 7 (Precursor Fabric of Example 7) A 30 gsm spunmelt nonwoven batt was produced on a production line in a continuous process from bicomponent filaments with a core / sheath ratio of 80:20. The core was made of an aliphatic polyester (PLA Ingeo 6100D, Nature Works), and the sheath was made of an aliphatic polyester with low melting point and crystallinity (PLA Ingeo 6752s, Nature Works) and a lubricant (Avient CR Bio 2144, Avient). Bicomponent filaments with fiber diameters of 15-30 μm were produced and then collected on a moving belt. The batt was produced from a single spunbond beam with REICOFIL4 technology. The nonwoven batt was completely bonded by a pair of heated rollers, where one roller had a raised pattern P1 (Figure 4A). The temperatures of the calender rollers (smooth roller / pattern roller) were 140°C / 138°C, and the bonding pressure was 50 N / mm. The resulting nonwoven fabric had the material properties shown in Table 4.

[0159] Example 7 The same nonwoven fabric as described in Comparative Example 7 was formed, but with the addition of a hydropatterning step. The hydropatterning was performed using two drums. The first drum had a wire mesh screen and one jet disposed on the drum applying a water pressure of 80 bar, the one jet on the first drum having two rows of holes, the holes in each band being spaced 1.2 mm apart from each other. The second drum had an MPC screen and three jets applying water pressures of 90 bar, 90 bar, and 150 bar, respectively. Each of the three jets on the second drum had two bands of holes, the holes in each band being spaced 0.6 mm apart from each other. The travel speed of the nonwoven fabric was 100 m / min. The resulting nonwoven fabric had the material properties shown in Tables 2 and 3.

[0160] [Table 2]

[0161] [Table 3]

[0162] As is evident from Table 2, the thickness of each nonwoven fabric described in Examples 1-6 is improved over the corresponding Comparative Example, and the mechanical properties are reduced to a certain level. The results vary depending on the thermal bond pattern on the precursor. Examples 1 and 2 show the difference between a low bonded (not fully bonded) precursor and a fully bonded precursor with the same pattern and the same process conditions. Both examples show a positive effect on thickness (22% and 17%, respectively), with the low bonded material having a higher thickness increase (22%) compared to the fully bonded material. The difference is not large, but still noticeable. Of note is the difference in the reduction of mechanical properties, with the reduction in tensile strength in both CD and MD being significantly lower for the fully bonded material (-22% in MD, -35% in CD) than the low bonded material (-35% in MD, -54% in CD). Since proper adhesion level is a key factor for fabric tensile strength, the tensile strength of the fully bonded precursor was higher compared to the low bonded precursor, and the difference in tensile strength after hydropatterning was even greater.

[0163] The examples show the effect of different thermal bond pattern types on the final fabric properties. Examples 1 and 2 use patterns with large-diameter-like adhesive indentations that vary the free filament area between the indentations. As expected, this combination results in a relatively large decrease in mechanical properties along with a moderate increase in thickness. According to the current disclosure, when large-diameter-like adhesive indentations are present in a pattern without changing the free filament area, as is the case with pattern P1, the decrease in mechanical properties is expected to be at least the same as observed in Examples 1 and 2, with a less significant increase in thickness. In contrast, when large-diameter-like adhesive indentations are placed to create a larger free filament area, a larger increase in thickness can be expected.

[0164] Example 3 shows the desirable mechanical properties of the precursor provided by linear discontinuous adhesive indentations arranged in a regular pattern of rows and columns. This design with offset linear rows results in a free filament area with a circle C of radius 0.99 mm. As expected, Example 3 shows minimal mechanical degradation (+1% and -3% of values) and a significant increase in thickness (+14%). Note that this increase is not comparable to Examples 1 and 2 due to the different polymer compositions. The use of a higher amount of copolymer in the polymer composition of Example 3 results in a softer fabric with more flexible filaments (see H-O-M values) and does not achieve the same level of thickness as the slightly stiffer polymer composition used in Examples 1 and 2.

[0165] Example 4 uses a continuous linear adhesive indentation with a convex portion and a large free filament area with a circle C of radius 2.18 mm. As expected, Example 4 shows minimal mechanical degradation (-4%; +5%) and a significant increase in thickness (+11%). Using small diameter-like adhesive indentations of the same shape as Example 4, a larger increase in thickness can be expected since the filaments are not fixed in a closed continuous adhesive shape. It is also expected that large diameter-like discontinuous linear adhesive indentations forming a similar design to P7 will increase thickness and also provide mechanical properties somewhere between the adhesive indentations, which are provided by the same shape formed from the P7 pattern and small diameter-like adhesive indentations.

[0166] Pattern P7 provides a high level of tensile strength (see MDT values ​​compared to other examples) while also providing a subjective sensation of soft touch in contact with human skin. This subjective value is not easily expressed in a single measurement and is evaluated by a group of trained people. A significant increase in this subjective sensation of soft touch was observed. Both precursor fabrics and treated products were observed under an electron microscope, and the difference can be seen in Figures 12A and 12B. Although the adhesive impression may appear unclear in the hydropattern photographs, without being bound by theory, it is believed that the energy flux does not generate enough energy to significantly damage the linear adhesive impression, but may partially change the adhesive impression surface, making it softer in human perception. It is noted that an increase in the subjective sensation of soft touch was observed in all hydropattern treated samples.

[0167] In Example 5, the adhesive indentation was small (0.9 mm 2 ), large diameter adhesive indentation (23.7mm 2 ), and free filament area (circle C radius 2.54 mm). As expected, a significant increase in thickness (+54%) was observed in Example 5. Without being bound by theory, it is believed that the significant increase in thickness is due to the large radius of circle C combined with the small diameter-like adhesive indentations that form a border around the free filament area. The decrease in mechanical properties due to the presence of the large diameter-like adhesive indentations is within acceptable limits (-36%; -29%). It is noted that the final fabric had a visual 3D-like "cushion" effect resulting from the large diameter-like adhesive points of the P5 pattern.

[0168] Although the foregoing specification has provided detailed descriptions of specific embodiments of the invention, it will be understood that many of the details provided herein may be significantly altered by those skilled in the art without departing from the spirit and scope of the invention.

[0169] The "tensile strength" and "elongation" of nonwoven fabrics are measured using a test method that conforms to the NONWOVEN STANDARD PROCEDURES (WSP) 110.4.R4 (12) standard. Tensile strength can also be expressed as "MDT" in the MD direction and "CDT" in the CD direction. Therefore, elongation can also be expressed as "MDE" in the MD direction and "CDE" in the CD direction.

[0170] The "Handle-O-Meter" or "HOM" stiffness evaluation of nonwoven materials is performed using WSP Test Method 90.3 with some modifications. The quality of "hand" is considered as the combined resistance due to surface friction and bending stiffness of the sheet material. The equipment used for this test method is manufactured by Thwing Albert Instruments. In this test method, 100x100mm samples were used for HOM measurement and the final reading obtained was recorded "as is" in grams instead of doubling the reading as per WSP Test Method 90.3. The average HOM was determined by taking the average of the MD and CD HOM values. Generally, the lower the HOM value, the softer and more flexible the material is, and a higher HOM value means that the nonwoven is less soft and flexible.

[0171] The "thickness" or "measurement height" or "caliper" of nonwoven materials is measured by the test measurement method according to the European standard EN ISO 9073-2:1995 (corresponding to method WSP120.6) and corrected in the following manner: 1. Materials shall be measured using samples taken from the manufacturing process, which have not been subjected to high deformation forces or pressure effects (e.g. pressure from rollers on manufacturing equipment) for more than one day, or shall be left on the surface for at least 24 hours. 2. The total pressure applied during thickness measurement is 14.7g / cm 2 It is.

[0172] The "Kinematic Coefficient of Friction" or "Dynamic CoF" of nonwoven materials is measured using a Testing Machines Corporation 32-07 Series Friction Tester in accordance with ASTM Standard D1894. Data reported represent the nonwoven-nonwoven kinetic coefficient of friction (CoF) of a 10 cm x 10 cm nonwoven placed under a 200 g sled, pulled across a fixed 25 cm x 10 cm specimen of the same nonwoven specimen at a rate of 150 mm / min while maintaining plane and orientation conformity (A-side to A-side; MD to MD).

[0173] Abrasion evaluation "Martindale average abrasion resistance rating test" or "Martindale" Fig. 13 is a perspective view showing the apparatus for the Martindale average abrasion resistance rating test. Specifically, Fig. 14 shows the rating index for evaluating fuzzing in the Martindale average abrasion resistance rating test.

[0174] The Martindale average abrasion resistance rating of the nonwoven fabric is measured by a Martindale abrasion tester. The test is carried out under dry conditions. 1. Condition the nonwoven fabric sample at a temperature of 23±2°C and a relative humidity of 50±2% for 24 hours. 2. Cut ten circular samples, each 162 mm (6.375 in) in diameter, from each nonwoven sample. Cut the reference felt into a 140 mm diameter circle. 3. For each sample, first place the cut-out felt on each position of the Martindale test polishing table, then fix the cut-out nonwoven fabric sample in place. After that, fix the clamp ring so that the nonwoven fabric sample does not wrinkle. 4. Assemble the abrader holder. The abrader is a 38 mm diameter, 1 / 32 inch thick silicone rubber (McMaster-Carr part number 86045K21-50A) that is FDA compliant. Place the desired weight in the abrader holder so that a pressure of 9 kPa is applied to the sample. Place the assembled abrader holder into the Model #864 so that the abrader is in contact with the nonwoven (NW) sample as instructed in the Operator Guide. 5. Martindale abrasion is performed under the following conditions: 1. Mode: Abrasion test 2. Speed: 47.5 cycles / min 3. Cycles: 80 cycles (unless otherwise specified) 6. After the test is completed, place the polished nonwoven on a smooth, non-shiny black surface and rate the level of fuzzing using the scale shown in Figure 14. Evaluate each sample by observing both from above to determine the size and number of defects and from the side to determine the height of the defect protrusions. Assign a number from 1 to 5 to the sample that best meets each rating scale. The Martindale Average Abrasion Resistance Grade is then calculated as the average rating of all samples and reported to the nearest grade on a 10-point scale.

[0175] The "percentage of adhesive area" was determined by using ImageJ software (Version 1.43u, National Institutes of Health, USA) to identify a single repeating pattern of adhesive impressions and non-adhesive areas, and enlarging the image so that the repeating pattern filled the field of view. A frame was drawn in ImageJ to surround the repeating pattern. The area of ​​the frame was calculated and adjusted to within 0.01 mm. 2 Then, using the area tool, trace each adhesive impression or part of it completely into the frame and calculate the area of ​​all adhesive impressions or parts of it that are within the frame. 2 Record in increments. Calculate as follows: Adhesive area percentage = (total area of ​​adhesive impressions within the frame) / (area of ​​the frame) x 100% Repeat the above procedure for a total of five non-adjacent regions of interest (ROIs) randomly selected across the test specimen. Record as percentage bonded area to the nearest 0.01%. Measurements are performed on both comparative and example specimens for each article. Three identical articles are measured for each sample set. Calculate the mean and standard deviation of the 30 percent bonded area measurements and report to the nearest 0.001.

Claims

1. 1. A method of forming a hydropatterned nonwoven fabric, comprising: forming a nonwoven batt of continuous spunmelt fibers; calendering the nonwoven batt to form a thermally bonded precursor nonwoven textile having a bond pattern defining bond impressions and unbonded areas between individual bond impressions; and Hydraulically treating the thermally bonded precursor nonwoven fabric with multiple water jets as the fabric passes over a screen. Including, The adhesive area of ​​the adhesive pattern is 10% to 25% in percentage, Define an imaginary circle C as the largest circle describable between the non-bonded regions and having a perimeter that intersects with a point on the perimeter of each of at least two adjacent bonded impressions in the bond pattern, the circle C having a radius of at least 0.5 mm, preferably at least 1.0 mm, more preferably at least 1.5 mm, and even more preferably at least 2.0 mm in the non-bonded regions; The adhesive pattern has an adhesive impression area of ​​at least 1 mm 2 It consists of a large diameter adhesive indentation A method comprising:

2. 2. The method of claim 1, wherein in the step of forming said precursor fabric, said spunmelt fibers of said nonwoven batt comprise spunbond filaments.

3. 2. The method of claim 1, wherein in the step of forming the precursor fabric, the nonwoven batt comprises two or more layers.

4. 2. The method of claim 1, wherein in the step of forming said precursor fabric, said continuous spunmelt fibers comprise a polyolefin, or a polyamide, or a polyester, or a polysaccharide homopolymer, copolymer, or polymer blend.

5. 2. The method of claim 1, wherein in the step of forming said precursor fabric, said spunmelt fibers comprise multicomponent, preferably bicomponent, continuous spunmelt fibers.

6. 2. The method of claim 1, wherein in the step of forming said precursor fabric, the minimum distance between adjacent said adhesive impressions is at least 0.3 mm.

7. 2. The method according to claim 1, wherein in the step of forming the precursor fabric, the adhesive impression is in the form of a line having a constant width (W) of up to 0.6 mm.

8. 2. The method of claim 1, wherein in the step of forming the precursor fabric, the adhesive impressions are in the form of lines of irregular width with a line width (W) of up to 0.6 mm.

9. 2. The method of claim 1, wherein in the step of forming the precursor fabric, the adhesive impression is a line shape having an outer adhesive shape perimeter that includes at least one protrusion.

10. 2. The method of claim 1, wherein in the step of forming the precursor fabric, the adhesive impression is in the form of a continuous line.

11. 2. The method of claim 1, wherein the water pressure treating step comprises applying water pressure to the nonwoven precursor fabric with water jets.

12. 2. The method of claim 1, wherein said water pressure treating step includes the step of at least partially altering each of said adhesive impressions by application of water pressure.

13. 13. The method of claim 12, wherein the at least partially changing step results in at least 60% of the fully bonded portions of the individual adhesive impressions remaining after the step of applying water pressure, preferably at least 70% of the fully bonded portions of the individual adhesive impressions remaining after the step of applying water pressure, more preferably at least 80% of the fully bonded portions of the individual adhesive impressions remaining after the step of applying water pressure, and most preferably at least 90% of the fully bonded portions of the individual adhesive impressions remaining after the step of applying water pressure.

14. 13. The method of claim 12, wherein said at least partially varying step divides each of said adhesive impressions into at least two portions.

15. 13. The method of claim 12, wherein the at least partially transforming step causes fibers in areas around the perimeter of each of the adhesive impressions to fray randomly in and out of the major plane of the fully bonded precursor nonwoven textile, such that at least a portion of each of the adhesive impressions are no longer three-dimensional.

Images