ZONED SPINNERET AND NONWOVEN FABRICS

TECHNICAL FIELD

Embodiments of the presently-disclosed invention relate generally a spinneret and a die including a spinneret, in which the spinneret includes zones configured to simultaneously melt-spin defined regions of a first group of monocomponent fibers having a first melting point and/or degree of crystallinity and a second group of monocomponent fiber having a second melting point and/or degree of crystallinity (e.g., amorphous) from a single polymeric composition. Embodiments of the presently-disclosed invention also relate generally to nonwoven fabrics and methods of forming such nonwoven fabrics.

BACKGROUND

In nonwoven fabrics, bicomponent fibers may be used in which a component of the bicomponent fibers, such as a sheath component of a bicomponent fibers having a sheath/core configuration, may be formed from a lower melting point polymeric composition while the other component is formed from a different polymeric composition that has a higher melting point. In this regards, the component of the bicomponent fibers formed from the lower melting point polymeric composition may be used for consolidation while maintaining the structural integrity of the component of the bicomponent fibers formed from the polymeric composition having the higher melting point. Alternatively, nonwoven fabrics may be formed from a mixture of fibers formed from different polymeric materials, such as a first group of fibers formed from a lower melting point polymeric composition and a second group of fibers formed from a higher melting point polymeric composition. Each of these approaches, however, requires the use of multiple polymeric compositions as well as multiple polymer flow pathways from respective polymer sources to respective spinneret capillaries.

Therefore, there remains a need in the art for methods and equipment that that utilize a single polymeric composition to provide nonwoven fabrics that include lower melting point regions, such as for consolidation, and higher melting point regions that may optionally remain in a solidified state during consolidation.

SUMMARY OF INVENTION

One or more embodiments of the invention may address one or more of the aforementioned problems. Certain embodiments according to the invention provide a spinneret for melt-spinning polymeric fibers comprising a spinneret body defining a plurality of orifices extending through the spinneret body, in which the plurality of orifices each comprise a capillary that is open at a face of the spinneret body for polymer filament extrusion therefrom. The plurality of orifices include (i) a first group of orifices each having a first capillary having a first capillary length (L) and first capillary hydraulic diameter (D_H) defining a first L/D_Hratio; and (ii) a second group of orifices each having a second capillary having a second capillary length (L) and second capillary hydraulic diameter (D_H) defining a second L/D_Hratio. The first L/D_Hratio, in accordance with certain embodiments of the invention is larger than the second L/D_Hratio. In this regard, fibers formed through the first group of orifices will have a higher melting point and/or degree of crystallinity as compared to fiber formed through the second group of orifices. In accordance, with certain embodiments of the invention, the first group of orifices define at least one first zone at the face of the spinneret body, and the second group of orifices define at least one second zone at the face of the spinneret body.

In another aspect, the present invention provides a die comprising a spinneret, such as those described and disclosed herein, and a polymer distribution pathway operatively connecting a first inlet to each of the plurality of orifices of the spinneret. In accordance with certain embodiments of the invention, the spinneret includes a spinneret body defining a plurality of orifices extending through the spinneret body, in which the plurality of orifices each comprise a capillary that is open at a face of the spinneret body for polymer filament extrusion therefrom. The plurality of orifices include (i) a first group of orifices each having a first capillary having a first capillary length (L) and first capillary hydraulic diameter (D_H) defining a first L/D_Hratio; and (ii) a second group of orifices each having a second capillary having a second capillary length (L) and second capillary hydraulic diameter (D_H) defining a second L/D_Hratio. The first L/D_Hratio, in accordance with certain embodiments of the invention is larger than the second L/D_Hratio. In this regard, fibers formed through the first group of orifices will have a higher melting point and/or degree of crystallinity as compared to fiber formed through the second group of orifices. In accordance, with certain embodiments of the invention, the first group of orifices define at least one first zone at the face of the spinneret body, and the second group of orifices define at least one second zone at the face of the spinneret body.

In another aspect, the present invention provides a system comprising a die, such as those described and disclosed herein, and a polymer source comprising a polymeric composition, in which the polymer source is operatively connected to the first inlet of the die. The polymer source, for example, may comprises a hopper, an extruder, and a metering pump, in which the hopper has a hopper outlet operatively connected to an extruder inlet, and the extruder has an extruder outlet operatively connected to a metering pump inlet, and the metering pump has a metering pump outlet operatively connected to the first inlet of the die.

In another aspect, the present invention provides a nonwoven fabric. The nonwoven fabric may comprise a plurality of interlaid fibers comprising a plurality of monocomponent fibers. The plurality of monocomponent fibers include (i) a first group of monocomponent fibers, the first group of monocomponent fibers having a first onset of melting temperature or melting temperature and (ii) a second group of monocomponent fibers defining at least one second region, the second group of monocomponent fibers having a second onset of melting temperature or melting temperature, wherein the second onset of melting temperature is lower than the first onset of melting temperature. The plurality of monocomponent fibers being formed from a single polymeric composition (e.g., the first group of monocomponent fibers and the second group of monocomponent fibers are formed from the same polymeric composition).

In another aspect, the present invention provides a composite comprising a nonwoven fabric, such as those described and disclosed herein, a film layer bonded (e.g., directly or indirectly) to the nonwoven fabric. The film layer, for example, may comprise a vapor permeable, liquid impermeable film layer.

In yet another aspect, the present invention provides a method of producing a nonwoven fabric, such as those described and disclosed herein. The method may comprise simultaneously melt spinning a plurality of monocomponent fibers from a single polymeric composition via a single spinneret, in which the plurality of monocomponent fibers comprise a first group of monocomponent fibers having a first onset of melting temperature or first melting point and a second group of monocomponent fibers having a second onset of melting temperature or a second melting point. The second onset of melting temperature being lower than the first onset of melting temperature. In accordance with certain embodiments of the invention, the first group of monocomponent fibers may have a higher melting point and/or degree of crystallinity as compared to the second group of monocomponent fibers. The plurality of monocomponent fibers form at least one first region including at least a majority (e.g., by number of fibers) of a portion of the first group of monocomponent fibers and at least one second region including at least a majority (e.g., by number of fibers) of a portion of the second group of monocomponent fibers. The method may also comprise collecting the plurality of monocomponent fibers, such as directly or indirectly onto a moving collection belt, and consolidating the plurality of monocomponent fibers, such as via a through-air-bonding process.

BRIEF DESCRIPTION OF THE DRAWING(S)

The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout, and wherein:

FIG. 1A illustrates a cross-sectional view of a spinneret illustrating a first orifice including a first capillary having a first diameter and a first length, a second orifice including a second capillary having a second diameter and a second length, in which the first length and the second length are the same while the first diameter is smaller than the second diameter in accordance with certain embodiments of the invention;

FIG. 1B illustrates a cross-sectional view of a spinneret illustrating a first orifice including a first capillary having a first diameter and a first length, a second orifice including a second capillary having a second diameter and a second length, in which the first diameter and the second diameter are the same while the first length is greater than the second length in accordance with certain embodiments of the invention;

FIG. 2 illustrates a spinneret including a zone of orifices with associated capillaries having a first L/D_Hratio and zone of orifices with associated capillaries having a second L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 3 illustrates a spinneret including a zone of orifices with associated capillaries having a second L/D_Hratio located adjacent and in between two zones of orifices with associated capillaries having a first L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 4 illustrates a spinneret including a spinneret including a zone of orifices with associated capillaries having a first L/D_Hratio located adjacent and in between two zones of orifices with associated capillaries having a second L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 5 illustrates a spinneret including alternating zones of orifices with associated capillaries having a first L/D_Hratio and orifices with associated capillaries having a second L/D_Hratio along a length direction (L) of the spinneret that may be associated with a machine direction (MD) when in operation, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 6 illustrates another spinneret including alternating zones of orifices with associated capillaries having a first L/D_Hratio and orifices with associated capillaries having a second L/D_Hratio along a length direction (L) of the spinneret that may be associated with a machine direction (MD) when in operation, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 7 illustrates a spinneret including alternating zones of orifices with associated capillaries having a first L/D_Hratio and orifices with associated capillaries having a second L/D_Hratio along a width direction (W) of the spinneret that may be associated with a cross-direction (CD) when in operation, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 8 illustrates a spinneret including alternating zones of orifices with associated capillaries having a first L/D_Hratio and orifices with associated capillaries having a second L/D_Hratio along a length direction (L) of the spinneret that may be associated with a machine-direction (MD) when in operation and a width direction (W) of the spinneret that may be associated with a cross-direction (CD) when in operation, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 9 illustrates a spinneret including a plurality of separate zones of orifices with associated capillaries having a first L/D_Hratio dispersed throughout a single zone or sea of orifices with associated capillaries having a second L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention;

FIG. 10 illustrates a spinneret including a plurality of separate zones of orifices with associated capillaries having a second L/D_Hratio dispersed throughout a single zone or sea of orifices with associated capillaries having a first L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention; and

FIG. 11 illustrates a spinneret, in accordance with certain embodiments of the invention, including a plurality of separate zones of orifices with associated capillaries, including a first zone of orifices with associated first capillaries having a first L/D_Hratio, a second zone of orifices with associated second capillaries having a second L/D_Hratio, and a third zone of orifices with associated second capillaries having a third L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, and the third L/D_Hratio is less than the second L/D_Hratio.

DETAILED DESCRIPTION

The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. As used in the specification, and in the appended claims, the singular forms “a”, “an”, “the”, include plural referents unless the context clearly dictates otherwise.

The presently-disclosed invention relates generally to spinnerets that generate a plurality of monocomponent fibers including a plurality of different groups of fibers that may each have a respective melting point or melting range despite each of the plurality of fibers being formed from the same single polymeric composition. The spinnerets, for example, may include at least one zone defined by capillaries having a first length-to-hydraulic diameter ratio and at least one second zone defined by capillaries having a second length-to-hydraulic diameter ratio that is different from the first length-to-hydraulic diameter ratio. In this regard, the particular length-to-hydraulic diameter ratio for a given capillary can impact the degree of crystallinity of the resulting fiber (e.g., moncomponent fiber), which may impact the melting point temperature and/or onset of melting point temperature of the resulting fiber. Fibers formed from capillaries having a larger length-to-hydraulic diameter ratio may have a higher degree of crystallinity and/or a larger melting point temperature and/or onset of melting point temperature as compared to fiber formed from capillaries having a smaller length-to-hydraulic diameter ratio. Accordingly, a single resin or polymeric composition may be melt-spun via a single spinneret and simultaneously provide a plurality of lower melting point fibers (e.g., less crystalline or amorphous) and a plurality of higher melting point fibers (e.g., more crystalline or semi-crystalline). In accordance with certain embodiments of the invention, for instance, resulting nonwoven webs (e.g., spunbond webs) may be consolidated via a through-air-bonding process in which, optionally, only the lower melting point fibers are softened, melted, and/or flowed throughout a portion of the nonwoven web to form bonds with the higher melting point fibers. In this regard, the structural integrity of the resulting nonwoven fabric, in accordance with certain embodiments of the invention, may be provided by the higher melting point fibers that may remain in a non-deformed or substantially non-deformed (e.g., the cross-section of the high melting point fibers remain the same or substantially the same before, during, and after the consolidation operation). To the contrary, the lower melting point fibers may have a deformed cross-section or individually undiscernible as individual fibers due to melting and/or flowing to provide the bonding mechanism for consolidation. For example, the lower melting point fibers may at least partially melt and flow through at least some of the gaps defined between the higher melting point fibers. As the lower point melting fibers flow through gaps between the higher melting point fibers, the deforming and flowing lower melting point fibers (e.g., less crystalline or amorphous) coat the surfaces of the higher melting point fibers. Upon solidification of the lower melting point material (e.g., the melted and flowed lower melting point fibers) after coating the surfaces of the higher melting point fibers, the lower melting point material forms bonds to and between the higher melting point material (e.g., the deformed lower melting point fibers). Accordingly, by the varying the length-to-hydraulic diameter of the capillaries of the different zones provides, for example, amorphous fibers and semi-crystalline fibers from the same (e.g., single) spinneret. Varying the length-to-hydraulic diameter of the capillaries of the different zones, for example, may result in different draw ratios due to the molten polymer experiencing different capillary exit speeds.

As used herein, a “spinneret” is a structure which includes a spinneret body having a number of small through-holes through which a fiber-forming polymer fluid is forced to form filaments or other fibers, and typically but not necessarily includes additional components used therewith, such as an overlying breaker plate for providing more uniform polymer feed distribution to the spinneret body, a filter layer or layers for filtering the polymer prior to its entering the breaker plate and/or spinneret body, or combinations thereof.

As used herein, “spinneret body” is typically one or more metal plates that comprises orifices, and these orifices comprising capillaries through which polymer is extruded to form filaments or other fibers. The spinneret body also may be an assembly of metal plate elements each having orifices that can form part of an overall pattern of orifices. A spinneret body can be, for example, a single-piece construction having an overall pattern of orifices or, alternatively may be assembled in modular fashion from a plurality of metal plate elements which as assembled together provide a body having an overall pattern of orifices.

As used herein, “capillary(ies)” refers to the small through-holes from which polymer exits the spinneret body to form the fiber. Capillaries have a length, a cross-sectional shape, hydraulic diameter, and length to hydraulic diameter ratio. While not mandatory in the present invention, in general the hydraulic diameter and cross-sectional shape are substantially uniform along the length of a capillary.

As used herein, “capillary length” or “length” refers to the length of the capillary through the spinneret body to a capillary opening at the face of the spinneret.

As used herein, the term “capillary cross-sectional area” or “CA” is a measurement of the exit area of the cross-sectional shape of one or more capillaries at the face of the spinneret body of the spinneret as described herein.

As used herein, “capillary perimeter” or “perimeter” or “CP” is the distance along the periphery defined by the exit geometry of the capillary at the face of the spinneret body surface. For a capillary having a circular cross-sectional shape, the perimeter is defined as the circumference of the capillary.

As used herein, “hydraulic diameter” or “D_H” is calculated by the formula:

D
_H=4R_H

wherein R_Hrepresent hydraulic radius. Hydraulic radius (R_H) is calculated from the ratio: CA/CP, wherein CA is the capillary cross-sectional area of the capillary opening at the polymer exit at the face of the spinneret body of spinnerets of the present invention, and CP is the capillary perimeter of the same capillary opening. For calculating the hydraulic diameter of a capillary having a circular cross-sectional shape and a diameter “D” thereof, for example, use of the indicated formula for hydraulic diameter provides: D_H=4*(πD²/4)/(TD), which reduces to D, which refers to a measurement of the longest dimension from one side of the circular cross-sectional shape or area to the other. The CA and CP values can be determined for the capillary openings at the polymer exit at the face of the spinneret body in spinnerets of the present invention, such as by capturing a digital image of a representative opening of a zone of capillaries, such as by Scanning Electron Microscope (SEM) or optical microscope which can include a calibration scale on the viewer and/or digital images generated therewith. One knowledgeable in the art will select a method to measure the capillary perimeter and cross-sectional area that is appropriate to the shape of the opening at the polymer exit at the face of the spinneret body in spinnerets of the present invention. These methods are typically based on studying the capillary opening at the polymer exit at the face of the spinneret body using a microscope and more typically an optical microscope. For example, for simple geometric shapes such as a circle, square, rectangle or triangle, one can use an optical microscope in combination with a calibration standard (e.g., optical grid calibration slide 03A00429Stage Mic 1MM/0.01 DIV from Pyser-SGI Limited, Kent UK) to measure the variables used to calculate either the perimeter or cross-sectional area. For more complex cross-sectional shapes, such are multi-lobal, an example of a method is to use a microscope capable of capturing the image of the polymer exit of the capillary opening at the face of the spinneret body digitally, and using software to analyze the image to calculate the perimeter and cross-sectional area of the exit at the face of the spinneret body. The cross-sectional area and perimeter dimensions of the capillary opening shape can be determined with use of any of calculations with known rules of geometry, or determinations using known or commercially available software algorithms applicable to evaluating digital or photographic images of cross-sectional shapes, or manual determinations.

As used herein, “capillary length to capillary hydraulic diameter ratio” or “length to hydraulic diameter ratio” refers to the numerical result of dividing a capillary length by a capillary hydraulic diameter.

The terms “substantial” or “substantially” may encompass the whole amount as specified, according to certain embodiments of the invention, or largely but not the whole amount specified (e.g., 95%, 96%, 97%, 98%, or 99% of the whole amount specified) according to other embodiments of the invention.

The terms “polymer” or “polymeric”, as used interchangeably herein, may comprise homopolymers, copolymers, such as, for example, block, graft, random, and alternating copolymers, terpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” or “polymeric” shall include all possible structural isomers; stereoisomers including, without limitation, geometric isomers, optical isomers or enantionmers; and/or any chiral molecular configuration of such polymer or polymeric material. These configurations include, but are not limited to, isotactic, syndiotactic, and atactic configurations of such polymer or polymeric material. The term “polymer” or “polymeric” shall also include polymers made from various catalyst systems including, without limitation, the Ziegler-Natta catalyst system and the metallocene/single-site catalyst system. The term “polymer” or “polymeric” shall also include, in according to certain embodiments of the invention, polymers produced by fermentation process or biosourced.

The terms “nonwoven” and “nonwoven web”, as used herein, may comprise a web having a structure of individual fibers, filaments, and/or threads that are interlaid but not in an identifiable repeating manner as in a knitted or woven fabric. Nonwoven fabrics or webs, according to certain embodiments of the invention, may be formed by any process conventionally known in the art such as, for example, meltblowing processes, spunbonding processes, needle-punching, hydroentangling, air-laid, and bonded carded web processes. A “nonwoven web”, as used herein, may comprise a plurality of individual fibers that have not been subjected to a consolidating process. In certain instances, the “nonwoven web” may comprises a plurality of layers, such as one or more spunbond layers and/or one or more meltblown layers. For instance, a “nonwoven web” may comprises a spunbond-meltblown-spunbond structure.

The terms “fabric” and “nonwoven fabric”, as used herein, may comprise a web of fibers in which a plurality of the fibers are mechanically entangled or interconnected, fused together, and/or chemically bonded together. For example, a nonwoven web of individually laid fibers may be subjected to a bonding or consolidation process to bond at least a portion of the individually fibers together to form a coherent (e.g., united) web of interconnected fibers.

The term “consolidated” and “consolidation”, as used herein, may comprise the bringing together of at least a portion of the fibers of a nonwoven web into closer proximity or attachment there-between (e.g., thermally fused together, chemically bonded together, and/or mechanically entangled together) to form a bonding site, or bonding sites, which function to increase the resistance to external forces (e.g., abrasion and tensile forces), as compared to the unconsolidated web. The bonding site or bonding sites, for example, may comprise a discrete or localized region of the web material that has been softened or melted and optionally subsequently or simultaneously compressed to form a discrete or localized deformation in the web material. Furthermore, the term “consolidated” may comprise an entire nonwoven web that has been processed such that at least a portion of the fibers are brought into closer proximity or attachment there-between (e.g., thermally fused together, chemically bonded together, and/or mechanically entangled together), such as by thermal bonding or mechanical entanglement (e.g., hydroentanglement) as merely a few examples. Furthermore, the term “consolidated” and “consolidation” may comprise the bonding by means of a through-air-bonding operation. The term “through-air bonded” and “though-air-bonding”, as used herein, may comprise a nonwoven web consolidated by a bonding process in which hot air is used to fuse the fibers at the surface of the web and optionally internally within the web. By way of example only, hot air can either be blown through the web in a conveyorized oven or sucked through the web as it passes over a porous drum as a vacuum is developed. The temperature of and the rate of hot air are parameters that may determine the level or the extent of bonding in nonwoven web. In accordance with certain embodiments of the invention, the temperature of the hot air may be high enough to melt, induce flowing, and/or fuse the a plurality of fibers having a lower melting point temperature or onset of lower melting point temperature (e.g., amorphous fibers) to a plurality of fibers having a higher melting point temperature or onset of lower melting point temperature (e.g., semi-crystalline or crystalline fibers). Such a web may be considered a “consolidated nonwoven”, “nonwoven fabric” or simply as a “fabric” according to certain embodiments of the invention.

As used herein, “meltspun” or “melt-spun” generally refers to fiber forming processes of spunbonding or melt-blowing.

The term “spunbond”, as used herein, may comprise fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular, capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced. According to an embodiment of the invention, spunbond fibers are generally not tacky when they are deposited onto a collecting surface and may be generally continuous as disclosed and described herein. It is noted that the spunbond used in certain composites of the invention may include a nonwoven described in the literature as SPINLACE®. Spunbond fibers, for example, comprise continuous fibers.

As used herein, the term “continuous fibers” refers to fibers which are not cut from their original length prior to being formed into a nonwoven web or nonwoven fabric. Continuous fibers may have average lengths ranging from greater than about 15 centimeters to more than one meter, and up to the length of the web or fabric being formed. For example, a continuous fiber, as used herein, may comprise a fiber in which the length of the fiber is at least 1,000 times larger than the average diameter of the fiber, such as the length of the fiber being at least about 5,000, 10,000, 50,000, or 100,000 times larger than the average diameter of the fiber.

The term “monocomponent”, as used herein, with respect to a fiber or collection of fibers means fiber(s) having the same or essentially the same composition (e.g., polymeric composition) across their cross-section. The polymer composition may, for example, include a polymer component (e.g., one or more polymers) and/or an additive component (e.g., surfactants, processing aids, fillers, etc.), in which a continuous phase of uniform composition (e.g., polymeric composition) extends across the cross-section and over the length of the fiber. To the contrary, the term “multi-component fibers”, as used herein, may comprise fibers formed from at least two different polymeric materials or compositions (e.g., two or more) extruded from separate extruders but spun together to form one fiber. The term “bi-component fibers”, as used herein, may comprise fibers formed from two different polymeric materials or compositions extruded from separate extruders but spun together to form one fiber. The polymeric materials or polymers are arranged in a substantially constant position in distinct zones across the cross-section of the multi-component fibers and extend continuously along the length of the multi-component fibers. The configuration of such a multi-component fiber may be, for example, a sheath/core arrangement wherein one polymer is surrounded by another, an eccentric sheath/core arrangement, a side-by-side arrangement, a pie arrangement, or an “islands-in-the-sea” arrangement, each as is known in the art of multicomponent, including bicomponent, fibers.

As used herein, the term “aspect ratio” comprises a ratio of the length of the major axis to the length of the minor axis of the cross-section of the fiber in question.

The term “machine direction” or “MD”, as used herein, comprises the direction in which the fabric produced or conveyed. The term “cross-direction” or “CD”, as used herein, comprises the direction of the fabric substantially perpendicular to the MD.

Certain embodiments according to the invention provide a spinneret for melt-spinning polymeric fibers comprising a spinneret body defining a plurality of orifices extending through the spinneret body, in which the plurality of orifices each comprise a capillary that is open at a face of the spinneret body for polymer filament extrusion therefrom. The plurality of orifices include (i) a first group of orifices each having a first capillary having a first capillary length (L) and first capillary hydraulic diameter (D_H) defining a first L/D_Hratio; and (ii) a second group of orifices each having a second capillary having a second capillary length (L) and second capillary hydraulic diameter (D_H) defining a second L/D_Hratio. The first L/D_Hratio, in accordance with certain embodiments of the invention is larger than the second L/D_Hratio. In this regard, fibers formed through the first group of orifices will have a higher melting point and/or degree of crystallinity as compared to fiber formed through the second group of orifices. In accordance, with certain embodiments of the invention, the first group of orifices define at least one first zone at the face of the spinneret body, and the second group of orifices define at least one second zone at the face of the spinneret body. In accordance with certain embodiments of the invention, the spinneret body may have a length and a width that is greater than the length. In this regard, the plurality of orifices may define a plurality of rows extending independently from each other along at least about 20% of the body width, such as at least about any of the following: 20, 30, 40, 50, 60, and 70% of the body width, and/or, at most about any of the following: 100, 95, 90, 80, and 70% of the body width.

In accordance with certain embodiments of the invention, the first L/D_Hratio may be from about 0.9 to about 10, such as at least about any of the following: 0.9, 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, and 4, and/or at most about any of the following: 10, 9.5, 9, 8.5, 8, 7.5, 7, 6.5, 6, 5.5, 5, 4.8, 4.5, 4.2, and 4. Additionally or alternatively, the second L/D_Hratio may be from about 0.8 to about 9, such as at least about any of the following: 0.8, 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, and 4, and/or at most about any of the following: 9, 8.5, 8, 7.5, 7, 6.5, 6, 5.5, 5, 4.8, 4.5, 4.2, and 4. Additionally or alternatively, the spinneret may include a zoned-ratio between the first L/D_Hratio and the second L/D_Hratio that may be from about 1.1:1 to about 12.5:1, such as at least about any of the following: 1.1:1, 1.2:1, 1.4:1, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.5:1, 2.8:1, 3:1, 3.2:1, 3.4:1, 3.5:1, 3.8:1, 4:1, 4.5:1, and 5:1, and/or at most about any of the following: 12.5:1, 12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5.8:1, 5.5:1, 5.2:1, 5:1, 4.8:1, 4.6:1, 4.5:1, 4.4:1, 4.2:1, and 4:1. Additionally or alternatively, the plurality of orifices may comprise from about 50 to about 95% by number of the first group of orifices (e.g., producing the semi-crystalline or more crystalline fibers), such as at least about any of the following: 50, 55, 60, 65, 70, and 75% by number of the first group of orifices, and/or at most about any of the following: 95, 90, 85, 80, and 75% by number of the first group of orifices. Additionally or alternatively, the plurality of orifices may comprise from about 5 to about 50% by number of the second group of orifices (e.g., producing the amorphous or less crystalline fibers), such as at least about any of the following: 5, 8, 10, 12, 15, 18, 20, 22, and 25% by number of the second group of orifices, and/or at most about any of the following: 50, 45, 40, 35, 32, 30, 28, and 25% by number of the second group of orifices. In accordance with certain embodiments of the invention, the first capillaries of the first group of orifices (e.g., monocomponent orifices) may have a first ribbon cross-section at the face of the spinneret body. For example, the first ribbon cross-section may have an aspect ratio from about 1.5:1 to about 10:1, such as at least about any of the following: 1.5:1, 2:1, 3:1, 4:1, and 5:1, and/or at most about any of the following: 10:1, 9:1, 8:1, 7:1, 6:1, and 5:1. Additionally or alternatively, the first capillaries of the first group of orifices (e.g., monocomponent orifices) may have a first round cross-section at the face of the spinneret body. For example, the first round cross-section has an aspect ratio from 0.8:1 to 1.2:1, such as at least about any of the following: 0.8:1, 0.9:1, and 1:1, and/or at most about any of the following: 1.2:1, 1.1:1, and 1:1. Additionally or alternatively, the second capillaries of the second group of orifices (e.g., monocomponent orifices) nay have a second ribbon cross-section at the face of the spinneret body. For example, the second ribbon cross-section may have an aspect ratio from about 1.5:1 to about 10:1, such as at least about any of the following: 1.5:1, 2:1, 3:1, 4:1, and 5:1, and/or at most about any of the following: 10:1, 9:1, 8:1, 7:1, 6:1, and 5:1. Additionally or alternatively, the second capillaries of the second group of orifices (e.g., monocomponent orifices) may have a second round cross-section at the face of the spinneret body. For example, the second round cross-section has an aspect ratio from 0.8:1 to 1.2:1, such as at least about any of the following: 0.8:1, 0.9:1, and 1:1, and/or at most about any of the following: 1.2:1, 1.1:1, and 1:1.

FIG. 1A, for instance, illustrates a cross-sectional view of a spinneret 1 illustrating a first orifice 2 including a first capillary 3 having a first diameter (D1) and a first length (L), a second orifice 4 including a second capillary 5 having a second diameter (D2) and a second length (L), in which the first length and the second length are the same while the first diameter is smaller than the second diameter in accordance with certain embodiments of the invention. In this regard, fibers formed from the first capillary 3 will have a more crystalline nature and exhibit a higher melting point temperature or higher onset of melting point temperature compared to fibers formed from the second capillary 5. FIG. 1B illustrates a cross-sectional view of a spinneret 1 illustrating a first orifice 2 including a first capillary 3 having a first diameter (D) and a first length (L1), a second orifice 4 including a second capillary 5 having a second diameter (D) and a second length (L2), in which the first diameter and the second diameter are the same while the first length (L1) is greater than the second length (L2) in accordance with certain embodiments of the invention. In this regard, fibers formed from the second capillary 5 will have a more crystalline nature and exhibit a higher melting point temperature or higher onset of melting point temperature compared to fibers formed from the first capillary 3.

FIG. 2, for example, illustrates a spinneret 1 including a zone of orifices with associated capillaries having a first L/D_Hratio and a zone of orifices with associated capillaries having a second L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention. As shown in FIG. 2, the at least one first zone of the first group of orifices 10 comprises a first group of one or more rows including a first outermost row extending along a width direction of the spinneret. In the particular spinneret of FIG. 2, the at least one second zone of the second group of orifices 20 comprises a different group of one or more rows including the second outermost row extending along the width of direction of the spinneret.

FIG. 3 illustrates, in accordance with certain embodiments of the invention, a spinneret 1 including a zone of orifices with associated capillaries having a second L/D_Hratio 20 located adjacent and in between two zones 10,15 of orifices with associated capillaries having a first L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio. In this regard, the at least one first zone comprises a second group of one or more rows including a second outermost row extending along the width direction of the spinneret body as shown in FIG. 3. Accordingly, the spinneret will form nonwoven webs having lower melting point fibers disposed between two regions of higher melting point fibers.

FIG. 4 illustrates yet another spinneret 1, in accordance with certain embodiments of the invention. FIG. 4 illustrates a spinneret 1 including a zone of orifices with associated capillaries having a first L/D_Hratio 10 located adjacent and in between two zones of orifices with associated capillaries having a second L/D_Hratio 20,25, in which the first L/D_Hratio is larger than the second L/D_Hratio.

In accordance with certain embodiments of the invention, and as illustrated in FIGS. 2 and 4, the at least one second zone (e.g., capillaries having a second L/D_Hratio) may comprise a first group of one or more rows including a first outermost row extending along a width direction of the spinneret. In certain embodiments, the at least one second zone comprises a second group of one or more rows including a second outermost row extending along the width direction of the spinneret, such as illustrated in FIG. 4. As shown in FIG. 4, the at least one first zone 10 comprises a third group of one or more rows extending along a width direction of the spinneret body and being located directly or indirectly between the first group of one or more rows and the second group of one or more rows.

The spinneret, in accordance with certain embodiments of the invention, may have a total number of rows, and the first group of one or more rows may comprise from about 1 to about 45% of the total number of rows, such as at least about 1, 3, 5, 8, 10, 12, 15, 18, and 20% of the total number of rows, and/or at most about any of the following: 45, 40, 38, 35, 32, 30, 28, 25, 22, and 20% of the total number or rows. Additionally or alternatively, the second group of one or more rows may comprise from about 1 to about 45% of the total number of rows, such as at least about 1, 3, 5, 8, 10, 12, 15, 18, and 20% of the total number of rows, and/or at most about any of the following: 45, 40, 38, 35, 32, 30, 28, 25, 22, and 20% of the total number or rows. Additionally or alternatively, the spinneret may have a total number of rows, and the third group of one or more rows (e.g., if there are two separate groups of either the first capillaries or the second capillaries) may comprise about 10 to about 99% of the total number of rows, such as at least about 10, 12, 15, 20, 25, 30, 35, 40, 45, and 50% of the total number of rows, and/or at most about any of the following: 99, 98, 95, 90, 85, 80, 75, 70, 65, 60, 55, and 50% of the total number or rows.

In accordance with certain embodiments of the invention, the at least one first zone comprises a plurality of first zones, and the at least one second zone comprises a plurality of second zones. By way of example only, FIG. 5 illustrates a spinneret 1 including alternating zones of orifices with associated capillaries having a first L/D_Hratio 10,15 and orifices with associated capillaries having a second L/D_Hratio 20,25 along a length direction (L) of the spinneret that may be associated with a machine direction (MD) when in operation, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention. Similarly, FIG. 6 illustrates another spinneret 1 including alternating zones of orifices with associated capillaries having a first L/D_Hratio 10,15,17 and orifices with associated capillaries having a second L/D_Hratio 20,25 along a length direction (L) of the spinneret that may be associated with a machine direction (MD) when in operation, in which the first L/D_Hratio is larger than the second L/D_Hratio, in accordance with certain embodiments of the invention. As generally illustrated by FIGS. 5 and 6, the spinneret may include a plurality of first zones and a plurality of second zones that are located in an alternating pattern along a length direction.

In accordance with certain embodiments of the invention, the at least one first zone comprises a plurality of first zones, and the at least one second zone comprises a plurality of second zones. By way of example only, FIG. 7 illustrates a spinneret 1 wherein the plurality of first zones 20a-20i and the plurality of second zones 10a-10g are located in an alternating pattern along a width direction.

In accordance with certain embodiments of the invention, the at least one first zone comprises a plurality of first zones, and the at least one second zone comprises a plurality of second zones. By way of example only, FIG. 8 illustrates a spinneret 1 in which the plurality of first zones 20a-20o and the plurality of second zones 10a-10o are located in an alternating pattern along both the length direction and the width direction.

FIG. 9 illustrates a spinneret 1 in which the at least one second zone 10 comprises a continuous sea of the plurality of orifices, and the at least one first zone comprises a plurality of first zones 20a-20c comprising islands of the plurality of orifices dispersed throughout the continuous sea of the plurality of orifices. Alternatively, FIG. 10 illustrates a spinneret 1 in which the at least one first zone 10 comprises a continuous sea of the plurality of orifices, and the at least one second zone comprises a plurality of second zones 10a-10e comprising islands of the plurality of orifices dispersed throughout the continuous sea of the plurality of orifices.

Although FIGS. 1A through FIG. 10 illustrate example spinnerets with capillaries each having one of only two (2) different L/D_Hratios, spinnerets in accordance with certain embodiments of the invention may comprise capillaries having from two or more different L/D_Hratios in the same spinneret. For example, a single spinneret may capillaries including from 2 to about 10 different (e.g., unique) L/D_Hratios, such as at least about any of the following: 2, 3, 4, and 5 different (e.g., unique) L/D_Hratios in the same spinneret, and/or at most about any of the following: 10, 9, 8, 7, 6, and 5 different (e.g., unique) L/D_Hratios in the same spinneret. Each of the capillaries having their respective L/D_Hratio may define one or more zones of such capillaries within the single spinneret. In this regard, the fibers extruded from the respective capillaries that can define corresponding respective zones thereof may provide a resulting nonwoven web having fibers formed from the same polymeric material but having a range of fibers with differing melting points and/or melting ranges, which may be distinct and/or unique (e.g., non-overlapping melting ranges) and/or have overlapping melting point ranges. By way of example only, a single spinneret may include a first zone of orifices with associated first capillaries having a first L/D_Hratio, a second zone of orifices with associated second capillaries having a second L/D_Hratio, and a third zone of orifices with associated third capillaries having a third L/D_Hratio, wherein the first L/D_Hratio is larger than the second L/D_Hratio, and the second L/D_Hratio is larger than the third L/D_Hratio. Accordingly, fibers formed or extruded from the first zone will have the most crystalline nature or degree and exhibit the highest melting point, while fibers formed or extruded from the third zone will have the least crystalline nature or degree (e.g., amorphous) and exhibit the lowest melting point, and the fibers formed or extruded from second zone will have a degree of crystallinity and melting point generally between those formed from the first and third zones. In this regard, the resulting nonwoven web (e.g., spunbond web) will be composed of three separate groups of fibers as determined by degree of crystallinity and/or melting point or melting range, in which all of the fibers of the nonwoven web are formed from the same resin or polymeric material. Such a formed nonwoven web, therefore, could be initially heat treated (e.g., annealed, lightly consolidated) to a temperature sufficient to melt the fibers formed from the third zone of capillaries (e.g., fibers with the lowest melting point) and lightly consolidate that nonwoven web to impart sufficient durability for subsequent processing (e.g., conveyance, mating with other materials, such as films, nonwovens, etc.). A final consolidation step may subsequently be performed by heating the fibers to a temperature that melts the fibers formed from the second zone of capillaries (e.g., fibers with the intermediate melting point) to provide a more robust level of consolidation, while the fibers formed from the first zone (e.g., fibers with the highest melting point) remain in a generally non-melted and/or non-deformed configuration as noted above.

FIG. 11 illustrates an example embodiment for a spinneret 100 including a first zone of orifices 110 with associated first capillaries having a first L/D_Hratio, a second zone of orifices 120 with associated second capillaries having a second L/D_Hratio, and a third zone of orifices 130 with associated second capillaries having a third L/D_Hratio, in which the first L/D_Hratio is larger than the second L/D_Hratio, and the third L/D_Hratio is less than the second L/D_Hratio. The first zone of orifices 110 may be located, for example, through a middle portion of spinneret and be located directly between two second zones of orifices 120, which may be bookended by two third zones of orifices 130 as illustrated by the example embodiment of FIG. 11. Although FIG. 11 illustrates one configuration of a spinneret including orifices having three (3) different L/D_Hratios, it should be understood that other configurations including different relative positioning of the different zones of orifices is contemplated.

In accordance with certain embodiments of the invention, the plurality of orifices are all monocomponent orifices having monocomponent capillaries (e.g., all orifices of the spinneret form monocomponent fibers). For example, the first capillaries of the first group of orifices, the second capillaries of the second group of orifices, or both are monocomponent spinning capillaries.

In another aspect, the present invention provides a nonwoven fabric. The nonwoven fabric may comprise a plurality of interlaid fibers comprising a plurality of monocomponent fibers. The plurality of monocomponent fibers include (i) a first group of monocomponent fibers having a first onset of melting temperature or melting temperature and (ii) a second group of monocomponent fibers defining at least one second region, the second group of monocomponent fibers having a second onset of melting temperature or melting temperature, wherein the second onset of melting temperature is lower than the first onset of melting temperature. The plurality of monocomponent fibers being formed from a single polymeric composition (e.g., the first group of monocomponent fibers and the second group of monocomponent fibers are formed from the same polymeric composition).

In accordance with certain embodiments of the invention, the first group of monocomponent fibers has a first melting point range, and the second group of monocomponent fibers has a second melting point range, in which the first melting point range and the second melting point range do not overlap. For example, a difference between the first melting point range and the second melting point range (e.g., closest temperatures between the two ranges) may be from 2 to 20° C., such as at least about any of the following: 2, 3, 4, 5, 6, 7, 8, 9, and 10° C., and/or at most about any of the following: 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, and 10° C.

As noted above, the nonwoven fabric, in accordance with certain embodiments of the invention, may be consolidated via the second group of monocomponent fibers. For instance, the second group of monocomponent fibers may be deformed (or individually indiscernible) from an initially spun cross-section and fused with the second group of monocomponent fibers.

In accordance with certain embodiments of the invention, the first group of monocomponent fibers may define at least a first higher melting point region including a first outermost surface of the nonwoven fabric. The first group of monocomponent fibers may further define a second higher melting point region including a second outermost surface of the nonwoven fabric. In accordance with certain embodiments of the invention, the second group of monocomponent fibers may define at least a first lower melting point region located adjacent to the first higher melting point region, the second higher melting point region, or both. Additionally or alternatively, the nonwoven fabric may have a total basis weight from about 10 grams-per-meter-squared (gsm) to about 200 gsm, such as at least about any of the following: 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 45, and 50 gsm, and/or at most about any of the following: 200, 180, 150, 120, 100, 80, 70, 60, and 50 gsm. Additionally or alternatively, the first group of monocomponent fibers may comprise from about 50 to about 90% by weight of the total basis weight, such as at least about any of the following: 50, 55, 60, 65, and 70% by weight of the total basis weight, and/or at most about any of the following: 90, 85, 80, 75, and 70% by weight of the total basis weight. Additionally or alternatively, the second group of monocomponent fibers may comprise from about 10 to about 50% by weight of the total basis weight, such as at least about any of the following: 10, 15, 20, 25, and 30% by weight of the total basis weight, and/or at most about any of the following: 50, 45, 40, 35, and 30% by weight of the total basis weight.

In accordance with certain embodiments of the invention, the second group of monocomponent fibers may define at least first lower melting point region including a first outermost surface of the nonwoven fabric. The second group of monocomponent fibers may further define a second lower melting point region including a second outermost surface of the nonwoven fabric. In accordance with certain embodiments of the invention, the first group of monocomponent fibers may define at least a higher melting point region located adjacent to the first lower melting point region, the second lower melting point region, or both. Additionally or alternatively, the nonwoven fabric may have a total basis weight from about 10 grams-per-meter-squared (gsm) to about 200 gsm, such as at least about any of the following: 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 45, and 50 gsm, and/or at most about any of the following: 200, 180, 150, 120, 100, 80, 70, 60, and 50 gsm. Additionally or alternatively, the first group of monocomponent fibers may comprise from about 50 to about 90% by weight of the total basis weight, such as at least about any of the following: 50, 55, 60, 65, and 70% by weight of the total basis weight, and/or at most about any of the following: 90, 85, 80, 75, and 70% by weight of the total basis weight. Additionally or alternatively, the second group of monocomponent fibers may comprise from about 10 to about 50% by weight of the total basis weight, such as at least about any of the following: 10, 15, 20, 25, and 30% by weight of the total basis weight, and/or at most about any of the following: 50, 45, 40, 35, and 30% by weight of the total basis weight.

In accordance with certain embodiments of the invention, the first group of monocomponent fibers define a plurality of first higher melting point regions, and the second group of monocomponent fibers define a plurality of first lower melting point regions. For example, the plurality of first higher melting point regions and the plurality of first lower melting point regions may be located in an alternating pattern along a machine-direction of the nonwoven fabric, a z-direction that is perpendicular to the machine-direction and a cross-direction, or both. In accordance with certain embodiments of the invention, the plurality of first higher melting point regions and the plurality of first lower melting point regions are located in an alternating pattern along a cross-direction of the nonwoven fabric, a z-direction that is perpendicular to the cross-direction and a machine-direction, or both. In accordance with certain embodiments of the invention, the plurality of first higher melting point regions and the plurality of first lower melting point regions are located in an alternating pattern along a cross-direction and a machine-direction. Additionally or alternatively, the plurality of first higher melting point regions and the plurality of first lower melting point regions are also located in an alternating pattern in a z-direction of the nonwoven fabric, wherein the z-direction is perpendicular to the cross-direction and the machine-direction. In accordance with certain embodiments of the invention, the nonwoven fabric may have a total basis weight from about 10 grams-per-meter-squared (gsm) to about 200 gsm, such as at least about any of the following: 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 45, and 50 gsm, and/or at most about any of the following: 200, 180, 150, 120, 100, 80, 70, 60, and 50 gsm. Additionally or alternatively, the first group of monocomponent fibers may comprise from about 50 to about 90% by weight of the total basis weight, such as at least about any of the following: 50, 55, 60, 65, and 70% by weight of the total basis weight, and/or at most about any of the following: 90, 85, 80, 75, and 70% by weight of the total basis weight. Additionally or alternatively, the second group of monocomponent fibers may comprise from about 10 to about 50% by weight of the total basis weight, such as at least about any of the following: 10, 15, 20, 25, and 30% by weight of the total basis weight, and/or at most about any of the following: 50, 45, 40, 35, and 30% by weight of the total basis weight.

The nonwoven fabric, in accordance with certain embodiments of the invention, includes the first group of monocomponent fibers that define a higher melting point region comprising a continuous region, and the second group of monocomponent fibers define a plurality of lower melting point regions comprising separate islands dispersed throughout the continuous region. Alternatively, the second group of monocomponent fibers may define a lower melting point region comprising a continuous region, and the first group of monocomponent fibers define a plurality of higher melting point regions comprising separate islands dispersed throughout the continuous region. Additionally or alternatively, the nonwoven fabric may have a total basis weight from about 10 grams-per-meter-squared (gsm) to about 200 gsm, such as at least about any of the following: 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 45, and 50 gsm, and/or at most about any of the following: 200, 180, 150, 120, 100, 80, 70, 60, and 50 gsm. Additionally or alternatively, the first group of monocomponent fibers may comprise from about 50 to about 90% by weight of the total basis weight, such as at least about any of the following: 50, 55, 60, 65, and 70% by weight of the total basis weight, and/or at most about any of the following: 90, 85, 80, 75, and 70% by weight of the total basis weight. Additionally or alternatively, the second group of monocomponent fibers comprises from about 10 to about 50% by weight of the total basis weight, such as at least about any of the following: 10, 15, 20, 25, and 30% by weight of the total basis weight, and/or at most about any of the following: 50, 45, 40, 35, and 30% by weight of the total basis weight.

In accordance with certain embodiments of the invention, the first group of monocomponent fibers may comprise a round outermost cross-section, a non-round outermost cross-section, or both. Additionally or alternatively, the first group of monocomponent fibers (e.g., continuous spunbond fibers) may comprise an average diameter from about 8 to about 40 microns, such as at least about any of the following: 8, 10, 12, 15, 18, and 10 microns, and/or at most about any of the following: 40, 28, 35, 32, 30, 28, 25, 22, and 20 microns. Additionally or alternatively, the first group of monocomponent fibers may comprise a round outermost cross-section having an aspect ratio from 0.8 to 1.2, such as about 0.8, 0.9, and 1, and/or at most about 1.2, 1.1, and 1. Additionally or alternatively, the first group of monocomponent fibers may comprise a non-round outermost cross-section having an aspect ratio of at least 1.5, such as at least about any of the following: 1.5, 2, 3, 4, and 5, and/or at most about any of the following: 10, 9, 8, 7, 6, and 5.

In accordance with certain embodiments of the invention, the first group of monocomponent fibers may comprise a combination of round outermost cross-section fibers and non-round outermost cross-section fibers. The round outermost cross-section fibers may comprise from 1 to about 99% of a total number of the first group of monocomponent fibers, such as at least about any of the following: 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50% of a total number of the first group of monocomponent fibers, and/or at most about any of the following: 99, 98, 95, 90, 85, 80, 75, 70, 65, 60, 55, and 50% of a total number of the first group of monocomponent fibers. Additionally or alternatively, the non-round outermost cross-section fibers may comprise from 1 to about 99% of a total number of the first group of monocomponent fibers, such as at least about any of the following: 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50% of a total number of the first group of monocomponent fibers, and/or at most about any of the following: 99, 98, 95, 90, 85, 80, 75, 70, 65, 60, 55, and 50% of a total number of the first group of monocomponent fibers.

In accordance with certain embodiments of the invention, the second group of monocomponent fiber may comprise a round outermost cross-section, a non-round outermost cross-section, or both. Additionally or alternatively, the second group of monocomponent fibers may comprise an average diameter from about 8 to about 40 microns, such as at least about any of the following: 8, 10, 12, 15, 18, and 10 microns, and/or at most about any of the following: 40, 28, 35, 32, 30, 28, 25, 22, and 20 microns. Additionally or alternatively, the second group of monocomponent fibers comprise a round outermost cross-section having an aspect ratio from 0.8 to 1.2, such as about 0.8, 0.9, and 1, and/or at most about 1.2, 1.1, and 1. Additionally or alternatively, the first second group of monocomponent fibers may comprise a non-round outermost cross-section having an aspect ratio of at least 1.5, such as at least about any of the following: 1.5, 2, 3, 4, and 5, and/or at most about any of the following: 10, 9, 8, 7, 6, and 5.

In accordance with certain embodiments of the invention, the second group of monocomponent fibers may comprise a combination of round outermost cross-section fibers and non-round outermost cross-section fibers. For example, the round outermost cross-section fibers may comprise from 1 to about 99% of a total number of the first group of monocomponent fibers, such as at least about any of the following: 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50% of a total number of the first group of monocomponent fibers, and/or at most about any of the following: 99, 98, 95, 90, 85, 80, 75, 70, 65, 60, 55, and 50% of a total number of the first group of monocomponent fibers. Additionally or alternatively, the non-round outermost cross-section fibers may comprise from 1 to about 99% of a total number of the first group of monocomponent fibers, such as at least about any of the following: 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50% of a total number of the first group of monocomponent fibers, and/or at most about any of the following: 99, 98, 95, 90, 85, 80, 75, 70, 65, 60, 55, and 50% of a total number of the first group of monocomponent fibers.

The first group of monocomponent fibers and the second group of monocomponent fibers, in accordance with certain embodiments of the invention, may comprise the single polymeric composition, in which the single polymeric composition comprises a polymer component comprising a polyolefin or copolymer thereof, a polyester or copolymer thereof, a polyamide or a copolymer thereof, or a biopolymer, such as polylactic acid. The polyolefin, for example, may comprise a polypropylene a copolymer thereof, a polyethylene a copolymer thereof, or blends thereof.

The nonwoven fabric, in accordance with certain embodiments of the invention, comprises a through-air-bonded nonwoven fabric. As noted above, the second group of monocomponent fibers may be amorphous or at least less crystalline than the first group of monocomponent fibers. In this regard, the second group of monocomponent fibers may have a deformed cross-section (or be individually indiscernible) from at least partially melting, flowing, and bonding to the first group of monocomponent fibers. In accordance with certain embodiments of the invention, the first group of monocomponent fibers have a non-deformed cross-section (e.g., as compared to prior to the laydown and/or pre-consolidated cross-section(s)).

In accordance with certain embodiments of the invention, the nonwoven fabric comprises a plurality of bond sites, such as from a thermal calandering operation or ultrasonic bonding operation. For example, the nonwoven fabric may have a bonded area defined by the plurality of bond sites, the bonded area comprising from about 1% to about 40%, such as at least about any of the following: 1, 2, 3, 5, 6, 8, 10, 12, 15, 18, 20, 21, and 22%, and/or at most about any of the following: 40, 38, 35, 32, 30, 28, 25, and 22%.

In accordance with certain embodiments of the invention, the film layer is a single layer film. The single layer film may be a vapor permeable, liquid impermeable (VPLI) film. The VPLI film, for example, may be a monolithic film (e.g., devoid or substantially devoid of micropores) or a microporous film. Alternatively, the film layer may comprise a multi-layer film including a core layer and at least a first skin layer. The multi-layer film, for example, may also include a second skin layer, in which the core layer is located between and adjacent the first skin layer and the second skin layer. In accordance with certain embodiments of the invention, the core layer may be a microporous layer or a monolithic layer. In accordance with certain embodiments of the invention, the first skin layer, the second skin layer, or both comprises a microporous layer or a monolithic layer. The multi-layer film, in accordance with certain embodiments of the invention, may be a VPLI film. following: 40, 38, 35, 32, 30, 28, 25, and 22%.

In accordance with certain embodiments of the invention, the film layer may have a basis weight from about 5 to about 50 gsm, such as at least about any of the following: 5, 10, 12, 15, 18, 20, 22, and 25 gsm, and/or at most about any of the following: 50, 45, 40, 35, 30, 28, and 25 gsm.

In accordance with certain embodiments of the invention, the film layer may be melt extruded directly onto the nonwoven fabric. Alternatively, the film layer may be adhesively bonded to the nonwoven fabric via an adhesive layer.

In accordance with certain embodiments of the invention, consolidating the plurality of monocomponent fibers comprises bonding the plurality of monocomponent fibers via a TAB process, in which the TAB process comprises subjecting the plurality of monocomponent fibers to an elevated temperature equal to or greater than the second onset of melting temperature. In accordance with certain embodiments of the invention, the elevated temperature is below the first onset of melting temperature. In this regard, the second group of monocomponent fibers may soften, melt, and/or at least partially flow prior to solidifying and bonding to the first group of monocomponent fibers. As noted above, second group of monocomponent fibers may have deformed cross-section as compared to an initial cross-section prior to being subjected to the TAB process and/or be individually indiscernible from one another. Additionally or alternatively, consolidating the plurality of monocomponent fibers comprises a thermal calendaring operation or a thermal area bonding operation. Additionally or alternatively, the consolidation method may comprises an ultrasonic bonding operation.

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

ZONED SPINNERET AND NONWOVEN FABRICS

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