WO2021028925A1

WO2021028925A1 - High barrier nonwoven substrate

Info

Publication number: WO2021028925A1
Application number: PCT/IL2020/050893
Authority: WO
Inventors: DeeAnn NELSON; Asaf KOTZER; Alon Zvigelski
Original assignee: Avgol Ltd.
Priority date: 2019-08-15
Filing date: 2020-08-13
Publication date: 2021-02-18
Also published as: AU2019100910A4

Abstract

The present invention is directed to a nonwoven substrate comprised essentially of filamentary components and more particularly to a filamentous material exhibiting useful fluidic control attributes while retaining aesthetic and physical performance necessary for mechanical processing of that material into useful and acceptable consumer products. The filamentous material includes at least one integrating network of essentially continuous filaments formed from at least one polymeric material. To said integrating network of continuous filaments a highly attenuated meltblown is applied wherein said meltblown exhibits smaller cross sectional diameters, higher diameter uniformity, and equivalent or better crystallinity. The resulting nonwoven substrate exhibits significant improvements in barrier and liquid management performance than technologies utilized heretofore.

Description

HIGH BARRIER NONWOVEN SUBSTRATE

BACKGROUND OF THE INVENTION

Nonwoven fabrics or substrates have been universally accepted and generally used in the construction of products exhibiting limited functional lifespans, such as components in disposable hygiene products, and specifically as a performance barrier in baby diapers, feminine hygiene products and adult incontinence devices. Particularly preferred nonwoven barrier substrates include those produced by meltspun “direct formation” fabrics such as the combination of spunbond and meltblown technologies, wherein the nonwoven substrate is fabricated rapidly and at reduced complexity and cost as compared to nonwoven fabrics utilizing finite length staple fiber manufacturing means. Over time, and in the interest of minimizing both raw material consumption and waste production, industries utilizing direct formation nonwoven fabrics have requested that the nonwoven fabric exhibit nominal weight while achieving specified performance targets such as air permeability and hydraulic head for increase end user comfort. This is particularly problematic in the production of a minimal weight nonwoven substrate having either finite or extended functional lifespan as there is a finite polymer mass of continuous filaments by which to achieve the performance requirements. Further, where it is desirable or advantageous to use chemical modification of one or more the continuous filaments in the nonwoven substrate, and given a finite filament polymer mass with which to treat or impart that chemical modification, issues of commercially viable, high speed, continuous production are encountered. This issue of continuous filament nonwoven substrates is particularly problematic when a material is desired to have a controlled fluidic barrier to certain predefined species and yet free fluidic passage to other species (i.e. breathable water barriers, oleophilic filter media, ethylene oxide sequestering, etc.) and yet retain required aesthetic and physical performance attributes. The present invention is directed to a nonwoven substrate comprised essentially of filamentary components and more particularly to a filamentous material exhibiting useful fluidic control attributes while retaining aesthetic and physical performance necessary for mechanical processing of that material into useful and acceptable consumer products. The filamentous material includes at least one integrating network of essentially continuous filaments formed from at least one polymeric material. To said integrating network of continuous filaments one or more layers of highly attenuated meltblown filaments are deposited. The highly attenuated meltblown filaments are produced using a volume of attenuation air flow that is at least 200% the volume conventionally practiced in current meltblown processes known to those skilled in the art. It is within the purview of the present invention that further employment of chemical surface energy modifiers in the integrating network of essentially continuous filamentous component and/or the highly attenuated meltblown layer or layers results in a material exhibiting a useful function of tactile and ductile properties while retaining finite control of fluids. Such finite fluid control includes management of both liquids and gases in the same composite. Further, nonwoven substrates incorporating the highly attenuated meltblown may optionally include one or more other layers comprised of spunbond, conventional meltblown, films, stable fiber, cellulosic pulps, superabsorbent materials and the mixtures or combinations thereof.

The successful production of a minimal mass, continuous filament nonwoven substrate is a compound problem comprising issues with formation of the continuous filament component to achieve required processing and end-use application physical and aesthetic performance attributes, suitable finite fluid management properties, and the attainment of these attributes by a viable commercial fabrication means wherein a nonwoven filamentous material exhibit useful aesthetic, physical and barrier qualities. Early prior art first address the means and methods of forming a basic spunmelt (as exemplified by spunbond and meltblown nonwoven technologies), such as is exemplified in U.S. Patent No.’s, 3,849,241 to Butin, et ah, 3,855,046 to Hansen, 4,041,203 to Brock, et al. and 7,611,594 to Sommer et al. U.S. Patent No. 5,464,688 to Timmons et ah, 5,662,978 and 6,100,208 to Brown et al. U.S. Patent No. 5,023,130 to Simpson et al., teaches a method by which unbonded continuous filaments are hydroentangled through application of high energy water jets. U.S. Patent No.’s 7,858,544 and 8,093,163 to Turi, et al. offer an approach wherein to attain suitable filament movement and integration it is necessary to have either a low thermal point bond of less than 10% of the material surface area or an anisoptropic bond pattern allowing for sufficient free filament length and engagement thereof. When one reviews the prior art more specific to end-use applications requiring high barrier performance, we again see the requirement for additional material layers which may be further formed into laminate or composite constructions. U.S. Patent No. 5,888,614 to Slocum et al., 6,929,853 to Forte, 6,420,002 to Bonke, et al, 7,396,498 to Johnstone and both 6,602,809 and 6,706,225 to Cabrey each are directed to the use of films, either alone or in combination with one or more other substrates to achieve a high barrier performance material. U.S. Patent No. 6.855,424 to Thomas et al., and 7,833,916 to Leeser et al. teach to use of foams applied to a substrate to impart a water vapor transfer performance. Each of the aforementioned prior art patents are incorporated by reference in their respective entireties.

While each of the above methods may produce a nonwoven fabric with a high barrier performance, the processes require the combination of film or foam layers, the means of such production result in either material of unfavorable consumer perceived qualities, complex or difficult production processes including additional chemical or mechanical modification steps, and/or materials that are problematic to convert into useful durable or semi-durable consumer products.

There remains an unmet need for a filamentous nonwoven substrate that exhibits functional fluid management barrier, light weight construction and aesthetic/physical features appealing to end-use customers, including durability and mechanical processing properties.

SUMMARY OF THE INVENTION

An object of the present invention is a nonwoven substrate exhibiting useful physical and aesthetic performance while imparting fluid management barrier attributes, which is suitable for mechanical processing into useful end-use products. The filamentous material includes at least one integrating network of essentially continuous filaments formed from at least one polymeric material and at least one highly attenuated meltblown component integrated therein. A further object of the present invention is the addition of at least one highly attenuated meltblown component to said integrating network results in a fluid management or barrier nonwoven exhibiting a useful function of mechanical converting or processing properties while retaining finite control of fluids.

A further object of the present invention is a fluid management or barrier nonwoven consisting essentially of an integrating network comprised of a spunbond component.

A further object of the present invention is a nonwoven substrate having a highly attenuated meltblown component wherein the attenuation volume of air is at least 200% of conventional air volumes used in commercially offered meltblown production lines.

A further object of the present invention is a nonwoven substrate having a highly attenuated meltblown component wherein the individual meltblown components exhibit 15% less filament to filament diameter variation than a conventional production process.

A further object of the present invention is a nonwoven substrate having a highly attenuated meltblown component wherein the individual meltblown components exhibit 10% finer filament to filament diameters than a conventional production process.

A further object of the present invention is a nonwoven substrate having a highly attenuated meltblown component wherein the nonwoven substrate has a normalized air permeability, or NAP (m³/m²/min/gm total basis weight), of 25% less than an equivalent combination and component weights of one integrating network of essentially continuous filaments and a conventional meltblown filaments.

A further object of the present invention is a nonwoven substrate having a highly attenuated meltblown component wherein the nonwoven substrate has a normalized hydraulic head, or NHH (cm/gm total basis weight), of 25% more than an equivalent combination and component weights of one integrating network of essentially continuous filaments and a conventional meltblown filaments. A further object of the present invention is a barrier nonwoven having retention of form and function when subjected to external forces, such as those imparted by stretching, loading, straining, wetting, or abrasion, whether such forces are of a singular, periodic, cyclical, or variable nature.

A further object of the present invention is a barrier nonwoven having finite fluid control wherein such control includes management of both liquids and gases in the same composite.

A further object of the present invention is a fluid management nonwoven substrate further comprising at least one mechanical process including, but not limited to, three- dimensional displacement of one or more component fibers, aperturing through one or more component fiber layers, and the combination thereof.

A further object of the present invention is a fluid management nonwoven substrate further comprising at least one chemical process including, but not limited to, increasing or decreasing the hydrophilicity or hydrophobicity of one or more component layers by topical or melt additive modification, increased tactile or ductile performance, altered aesthetic qualities such as coloration, and the combination thereof.

A further object of the present invention is a fluid management nonwoven substrate further comprises a superabsorbent fiber.

A further object of the present invention is a fluid management nonwoven substrate wherein the superabsorbent fiber is a component which is introduced before, during, or after the deposition of one or more highly attenuated meltblown components.

A further object of the present invention is a fluid management nonwoven substrate wherein nonwoven construct includes at least three component layers in relative surface orientation wherein a first component layer comprised of an integrating network of essentially continuous filaments forms one exterior planar surface, a second component layer comprised of an integrating network of essentially continuous filaments forms a second exterior planar surface opposite said first component layer, and at least one component layer comprised on highly attenuated meltblown filaments or filament fragments positioned intermediate between the first and second exterior surface layers. Said first component surface layer exhibits a philic performance that is greater than said second component surface layer, and wherein said intermediate layer(s) exhibits a philic performance less than said first component surface layer and greater than said opposite second component surface layer.

A further object of the present invention is a non woven material comprising highly attenuated meltblown filaments which exhibits attributes such as strength and elongation to allow and facilitate subsequent converting processes.

Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more easily understood by a detailed explanation of the invention including drawings. Accordingly, drawings, which are particularly suited for explaining the inventions, are attached herewith; however, it should be understood that such drawings are for descriptive purposes only and as thus are not necessarily to scale beyond the measurements provided. The drawings are briefly described as follows:

FIGURE 1 is a representative method of producing fluid management barrier nonwoven by a coadunation process in accordance with the present invention.

FIGURE 2 is a filamentous material in accordance with the present invention utilizing an asymmetric or anisotropic thermal bond pattern.

FIGURE 3 is a representative filamentous material in accordance with the present invention utilizing an asymmetric or anisotropic thermal bond pattern. FIGURE 4 is a representative filamentous material in accordance with the present invention utilizing an asymmetric or anisotropic thermal bond pattern.

FIGURE 5 is a representative filamentous material in accordance with the present invention utilizing a contiguous thermal bond pattern comprising a single bonding point extending completely though the machine direction, cross direction or combined machine and cross direction of the first repeating unit surface area.

FIGURE 6 is a representative filamentous material in accordance with the present invention utilizing a contiguous thermal bond pattern comprising thermal point bonds induced by a plurality of individual contact elements on a contact surface whereby the distance between any two individual contact elements is less than 0.5mm .

FIGURE 6A is an enlarged partial view of the area designated SA1 in FIGURE 6.

FIGURE 6B is an enlarged partial view of the area designated SA2 in FIGURE 6.

FIGURE 7A is an air permeability comparison chart of equivalent component basis weight materials utilizing commercially available meltblown production lines versus a highly attenuated meltblown in accordance with the present invention.

FIGURE 7B is a hydraulic head comparison chart of equivalent component basis weight materials utilizing commercially available meltblown production lines versus a highly attenuated meltblown in accordance with the present invention.

FIGURE 8 is a representative application of the present invention to create a fluid management construct.

FIGURE 9 is a representative application of the present invention to create a filamentous directional flow material. LIST OF REFERENCE NUMERALS

First component surface layer 10, intermediate component layer 20, second component surface layer 30.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated. Unless otherwise indicated, general practices in the art may be found in such collections as “Nonwoven Fabrics” by Albrecht, et al., incorporated herein by reference.

The present invention is directed to a nonwoven substrate comprising filamentary components and more particularly to a filamentous material exhibiting useful fluid management barrier attributes while retaining aesthetic and physical performance necessary for mechanical processing of that material into useful and acceptable consumer products. The filamentous material includes at least one integrating network consisting essentially of continuous filaments formed from at least one polymeric material. Suitable polymeric materials include thermal melt and thermoset polymers, with thermal melt plastics being particularly preferred. Thermal melt plastics include polyolefins, and more preferably polypropylene or polyethylene. Other polymers suitable for use include polyesters, such as polyethylene terephthalate; polyamides; polyacrylates; polystyrenes; thermoplastic elastomers, block polymers, polymer alloys; and blends of these and other known fiber forming thermoplastic materials.

Representative filamentous material in accordance with present invention are depicted in FIGURES 1 to 6B. It should be noted that pre-treatment by chemical or mechanical modification, and application of bonding energy may be effected by at various stages of lay-down of one or more integrating networks. Included in this process is at least one highly attenuated meltblown component. A representative means for production of an integrating network of continuous filaments includes those produced by spunbond nonwoven technology, though other preformed woven, knitted or other continuous spinning technologies are equally suitable, either alone or in combination. The spunbond continuous filaments used in the present invention have a component basis weight of at least about 1 gsm, with a preferred target final construct nonwoven substrate basis weight of 5 to 100 gsm and most preferably in the basis weight range of 10 to 60 gsm.

A process for the formation of spunbond as used to form the integrating network of continuous filaments involves supplying a molten thermal melt polymer, which is then extruded under pressure through a plate known as a spinneret or die head. The die head includes a spaced array of die orifices having diameters of generally about 0.1 to about 1.0 millimeters (mm). The resulting continuous filaments are quenched and drawn by any of a number of methods, such as slot draw systems, attenuator guns, or Godet rolls. The continuous filaments are collected as a loose web upon a moving collection surface, such as a wire mesh conveyor belt. When more than one spinneret is used in line for the purpose of forming a multi-layered fabric, the subsequent webs of filaments are collected upon the uppermost surface of the previously formed layer or web either continuously or in separately initiated batch processes.

The individual continuous filamentary elements within the integrating network may further be of homogenous or heterogeneous composition, include performance or aesthetic modifying melt additives, and be comprised of monocomponent, bicomponent, and/or multicomponent filament or fiber construction. Further, it is anticipated and within the purview of the present invention that one or more additional continuous filament integrating networks may be layered with a first continuous filament integrating network such that in the manufacturing or lay-down process: 1.) the components of each network type alternate in order of lay-down; 2.) two or more layers of a component type are sequentially ordered for lay-down; 3.) an equal number of component type are used; 4.) and odd number of component types are used; 5.) the amount of component types are introduced in equal mass, composition or diameter; 6.) the amount of component types are introduced in different, varying, or incremental adjustment of introduced mass, composition, or diameter; and, 7.) combinations thereof. As mentioned previously, one or more coadunation process steps and one or more optional consolidation steps may be used between one or more lay- down steps in the manufacturing process. Chemical based performance and/or aesthetic modifying melt additives includes one or more of those chemistries which result in modified properties of the filaments, such as to render the fibrous element with tactile softness, ductile softness, hydrophobic, oleophobic, anti-static, flame retardant, modify crystallinity or strength, alter melt- flow rheology, pigments, organic fillers and the like. A preferred embodiment of the present inventive material includes use of a hydrophobic melt additive. Representative hydrophobic melt additives include silicones, fluorochemicals, hindered amines, as well as nonionic, anionic and cationic surfactants and the like. U.S. Patent No. 8,080,613 to Moad et al, 7,790,807 to Brunner et ah, and 8,258,217 to Gerster, each represent admixture chemistries of particular interest and are hereby incorporated by reference in their respective entireties.

The web of continuous filaments, whether formed by a single spinneret station (i.e. a “beam”) or subsequent layers formed by one or more additional beams, are subjected in the manufacturing sequence to at least one application of a highly attenuated meltblown component. The highly attenuated meltblown component is a result of substantially increasing the mass of air acting upon a meltblown die such that volume of air is at least greater than 1.5x convention mass flow level as per practiced in the art, preferably greater than 2.0x flow level, and most preferably greater than 2.5x flow level.

Without being constrained to a specific theory of function or result, it is believed that the higher ratios of motive force in the form of air mass per unit time acting on a given fine polymer stream such as found in a meltblown technology creates a rapid draw of the stream into a proportionally larger number of finer filaments or filament fragments. These filaments or filament fragments in turn exhibit less diameter variation while retaining equivalent or better crystallinity as compared to existing commercial meltblown technologies wherein high velocity air streams (versus high total mass) are practiced.

The individual or combined layers or webs (whether continuous filament and/or highly attenuated meltblown) may be optionally consolidated at any step in the overall process, whether in an intermediate form or in a final, pre-conversion roll for, such as by means involving; 1.) heat and pressure, such as by thermal point bonding, 2.) application of hydraulic energy, such as by direct pressurized streams or sprays of water, 3.) chemical bonding, such as by glues or adhesives, 4) thermal bonding, such as passage of elevated of elevated temperature air through the material, and 5.) combinations thereof. When a thermal point bond consolidation method is used, the web or layers of webs come into contact with a thermal conductive roll, which may be either smooth or with an embossed pattern of individual contact elements to impart and achieve the desired degree of point bonding, usually on the order of 1 to 40 percent of the overall surface area being so bonded. These thermal point bonds may remain present in the final material, partially removed due to the application of a first degree of applied hydraulic energy, or essentially removed due to the application of a second degree of applied hydraulic energy. Further, the pattern or profile of the embossed roll may include a cross directional bias to the elements which impart the partial or complete consolidation of the fibrous components so as to alter the response of the fibrous components to force vector imparted by an applied hydraulic energy.

The formation of thermal point bonds by application of pressure and/or heat through direct contact of the integrating network of continuous filaments, the highly attenuated meltblown component, or combinations thereof with one or more patterned rolls or rollers can exhibit particularly useful attributes in terms of both mode of integration and material formation, as well as resulting performance attributes in the finished article. U.S. Patent numbers 6,537,644 and 6,610,390 to Kauschke, et ah, hereby incorporated by reference in their respective entireties, in conjunction with the previously referenced U.S. Patent No.’s 7,858,544 and 8,093,163 to Turi, et ah, direct their focus to fibrous materials exhibiting a defined nature of a bonding pattern to achieve a desired result (reference Figures 7, 8 and 9). Specifically, the referenced patents disclose nonwovens having a non-symmetrical pattern of fusion bonds (that is, an anisotropic or asymmetrical pattern). As disclosed in these documents, bonds in an asymmetrical pattern may have a common orientation and common dimensions, yet define a total bond area along one direction (e.g., the MD) greater than along another direction (e.g., the CD) which is oriented orthogonally to the first direction, such that the points form a uniform pattern of bond density in one direction different from the uniform pattern of bond density in the other direction. Alternatively, as also disclosed in these documents, the bonds themselves may have varying orientations or varying dimensions, thereby to form a pattern of bond density which differs along the two directions. The bonds may be simple fusion bonds or closed figures elongated in one direction. The bonds may be closed figures elongated in one direction and selected from the group consisting of closed figures (a) oriented in parallel along the one direction axis, (b) oriented transverse to adjacent closed figures along the one direction axis, and (c) oriented sets with proximate closed figures so as to form there between a closed configuration elongated along the one direction axis.

While practice of an asymmetrical bonding pattern can be used to beneficially impact the production and performance of spunmelt nonwoven fabric, the inventors have found that similar or enhanced properties can be obtained through a contiguous bonding pattern methodology. A contiguous bonding pattern is defined as a pattern of thermal point bonds wherein the pattern is comprised of a first and a second repeating unit surface area. The first and second repeating surface areas are proximal to one another such that pattern of repeating surface areas extending in both the machine direction of production (length) and the cross direction of production (width). The first repeating unit surface area includes a thermal bond area of 1.) of at least 30% of the total area making up the first repeating unit surface area or 2.) a single bonding point extending completely though the machine direction, cross direction or combined machine and cross direction of the first repeating unit surface area. The second repeating unit surface area comprises a thermal bond area of less than 10% of the total area making up the second repeating unit surface area.

In the instance, whereby the first repeating unit surface area is comprised of a thermal point bond of at least 30% of the total surface area of the first repeating unit surface area, the thermal point bond may be induced by a plurality of individual contact elements on a contact surface whereby the distance between any two individual contact elements is less than 0.5mm, as represented by Figure 6. As exemplified in Figure 6, multiple thermal point bonds are induced in the first repeating unit surface area (“SA1”) to create more bonding than are created in the adjacent second repeating unit surface area (“SA2”). It should be noted that the repeating unit surface area for SA1 and SA2 are defined as being rectilinear boundaries having the same total area. Further, it should be noted that a given SA1 will be circumscribed by a total of four (4) identical SA1 units, wherein each SA1 comes into contact with the vertex of an SA1 unit, (Figure 6A) and four (4) identical SA2 units, wherein each SA2 unit comes into contact with the side of an SA1 unit (Figure 6B). Conversely, it should be noted that a given SA2 will be circumscribed by a total of four (4) identical SA2 units, wherein each SA2 comes into contact with the vertex of an SA2 unit, and four (4) identical SA1 units, wherein each SA1 unit comes into contact with the side of an SA2 unit.

The individual components and/or the nonwoven substrate in accordance with the present invention, including selective application to continuous filament integrating network elements, to performance modifying filamentous components, or precursor combinations thereof, may be optionally subjected to mechanical modifications. Mechanical modifications include such exemplars as commonly understood by those skilled in the art, such as embossing, aperturing, application of hydraulic energy, tenting, stuffing, and the like. Embossing can include any suitable method of hot or cold rolls, ring rolls, and the like. Aperturing can be performed using interdigitated knifes or pins, which can form full material penetration, partial material penetration, and the combinations thereof. Water jet treatment allows for hydraulic energy to be imparted as a force on the elements in the filamentous material being produced. This hydraulic energy acts to displace or motivate elements with the filamentous material to inter-engage and form a composite performance, with such processes being known in the art as being “hydroentangled” or “hydroengorged”. Application of hydraulic energy may occur upon either expansive plane or face of the filamentous material being produced and may occur in one or more sequential or alternating steps. The water jets are preferably present in an amount of 1-10 heads or manifolds per side and the water is provided at a pressure predetermined by the quality of the resultant fabric desired. Preferably the pressure of the water in the jets is in a range of about 50-about 400 bar per head, with the range of 100 to 300 bar being preferred. Unique to the produced filamentous material of the present invention, a high degree of integration is obtained wherein the fiber volume, as defined by the basis weight divided by bulk, in the range of 0.05 milligrams/cubic centimeter to 0.40 milligrams/cubic centimeter and exhibits an air permeability of 250 1/sqm/sec or greater per gram/square meter material construct total or final weight. Through a combination of manufacturing controls and specific management of the filamentary and fibrous composition, production and lay-down, we have identified means by which to allow effective application of hydraulic energy to filamentous material having a low volume of filamentary and fibrous targets by which to impinge said hydraulic energy and induce movement by relative force vectors imparted thereby.

Following mechanical treatment, and preferably before final winding of the resultant nonwoven material, the nonwoven material can be treated with one or more chemical agents to further affect, e.g., enhance or modify, web secondary properties such as hydrophobicity, softness, flame retardancy, anti-static nature, and the like. The chemical agents may be topically applied over the entire surface of the filamentous material or within preselected zones. These zones may be provided with the same surfactant or additive or a different surfactant or additive in order to provide zones with different or the same properties. An example of topical treatment suitable for use is described in U.S. Pat. Nos. 5,709,747 and 5,885,656, incorporated herein by reference.

A variation upon the topical treatment of the filamentous material is that the surfactants can be applied as an array or in discrete strips across the width of the filamentous material in order to create zone treatments to which different performance, functional and/or aesthetic properties can be provided.

The invention allows for the production of a filamentous material in one continuous process including various features to provide new or enhanced properties within the filamentous material, in particular with respect to barrier and softness. However, the invention also allows for the production of the nonwoven filamentous material in different individual process stages, e.g., as a two or more-step process wherein one is the manufacture of the integrating network of continuous filaments, one is the application or manufacture of performance modifying filamentous components and one involving hydraulic processing of the composite. This versatility allows for capital cost savings since a continuous line does not have to be provided in one place or utilized at one continuous time. For example, a composite including an integrating network and a performance modifying filamentous component can be produced and then wound for temporary storage before being subjected to mechanical and/or chemical treatment. Further, the layers may be subjected to mechanical and/or chemical treatment to provide for a filamentous material of the invention which is usable as such or may be placed in storage and subsequently treated based upon a desired end use for the filamentous material. This versatility provides for cost efficiency in terms of plant space required for the provision of equipment, versatility in the use of different equipment with respect to timing and products and the ability to provide filamentous material with varying properties based on the application to which the material will be put.

The performance of the nonwoven material of the instant invention also lends itself beneficially to the inclusion of superabsorbent materials to create a fluid management stmcture, as shown in FIGURE 8. Application of one or more superabsorbent materials as either an intermediate layer between one or more continuous filament layers (“SB”) and one or more highly attenuated meltblown layers (“MB”), or as a congruent addition with one or more of any of the layers, will yield an absorbent structure. The degree of absorbent performance can be tailored through the mass of superabsorbent material is added as well as the combinations of different absorbent materials, such as superabsorbent fiber and cellulosic pulp, which is beneficial in the hygiene, medical, food packaging and related fields.

The present invention may also be employed to construct comprising filamentary components and more particularly to a filamentous directional flow material The filamentous directional flow material includes at least three component layers in relative surface orientation wherein a first component layer comprises one exterior planar surface, a second component layer comprises a second exterior planar surface opposite said first component layer, and at least one component layer comprising highly attenuated meltblown positioned intermediate between the first and second exterior surface layers. Said first component surface layer exhibits a preferential philic or phobic performance that is in turn greater than said second component surface layer, and wherein said intermediate layers exhibits a preferential liquid philic or phobic performance less than said first component surface layer and greater than said opposite second component surface layer (FIGURE 9).

The nonwoven substrate of the present invention exhibits retention of form and function when subjected to external forces, such as those imparted by stretching, loading, straining, wetting, or abrasion, whether such forces are of a singular, periodic, cyclical, or variable in nature. This durability aspect of the nonwoven substrate is useful in the making of numerous end-use consumer products, including but not limited to hygiene products, personal and surface wipes as well as medical products. Of particular importance, the durable aesthetic and physical performance of the inventive breathable barrier embodiment offers desirable integration as one or more components of baby diapers, feminine hygiene and adult incontinence products. An advantage of a durable yet soft barrier fabric is with regard to particulate retention such as when used in conjunction with a superabsorbent particle in a core and the desire is to also retain this particulate in the intended location or zone. A further advantage of this same inventive material is as a breathable backsheet material for a hygiene product wherein the material is a direct replacement for convention film/nonwoven laminations.

Apparatus useful in preparing the filamentous material of the invention is conventional in nature and known to one skilled in the art. Such apparatus includes extmders, conveyor lines, water jets, rewinders or unwinders, topical applicators, calenders or compactors, and the like.

EXAMPLE

Sample materials with highly attenuated filaments were produced in accordance with the present inventions and tested against equivalent component weight constmcts produced from conventional commercially available meltblown technology. All tests were conducted per industrial standards.

FIGURES 7 A and 7B presents normalized air permeability and hydraulic head respectively for representative samples. These samples were also reviewed by scanning electron microscopy to determine consistency of filament diameter. The sampling size for each material is n =100.

From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.

Claims

CLAIMS:

1. A non woven substrate comprising an integrating network of at least one essentially continuous filaments and at least one highly attenuated meltblown component, wherein said highly attenuated meltblown component is formed by an attenuation volume of air which is at least 200% of the air volumes as used in conventional meltblown technology.

2. A nonwoven substrate as claimed in Claim 1 wherein said attenuation air mass flow is equal to or greater than 1.5x.

3. A nonwoven substrate as claimed in Claim 1 wherein said attenuation air mass flow is equal to or greater than 2.0x.

4. A nonwoven substrate as claimed in Claim 1 wherein said attenuation air mass flow is equal to or greater than 2.5x.

5. A nonwoven substrate as claimed in Claim 1 wherein said essentially continuous filaments are comprised of a spunbond component.

6. A nonwoven substrate as claimed in Claim 1 wherein said highly attenuated meltblown component exhibit 15% less filament to filament diameter variation than a conventional production process.

7. A nonwoven substrate as claimed in Claim 1 wherein said highly attenuated meltblown component exhibit 10% finer filament to filament diameters than a conventional production process.

8. A nonwoven substrate as claimed in Claim 1 wherein said nonwoven substrate has a normalized air permeability, or NAP (m³/m²/min/gm total basis weight), of 25% less than an equivalent conventional material.

9. A nonwoven substrate as claimed in Claim 1 wherein said nonwoven substrate has a normalized hydraulic head, or NHH (cm/gm total basis weight), of 25% more than an equivalent conventional material.

10. A nonwoven substrate as claimed in Claim 1 wherein said nonwoven substrate further comprises at least one mechanical process including, but not limited to, three- dimensional displacement of one or more component fibers, aperturing through one or more component fiber layers, and the combination thereof.

11. A nonwoven substrate as claimed in Claim 1, wherein said nonwoven substrate further comprises at least one chemical process including, but not limited to, increasing or decreasing the hydrophilicity or hydrophobicity of one or more component layers by topical or melt additive modification, increased tactile or ductile performance, altered aesthetic qualities such as coloration, and the combination thereof.

12. A nonwoven substrate as claimed in Claim 1 wherein said nonwoven substrate is a barrier nonwoven fabric having finite fluid control wherein such control includes management of both liquids and gases in the same composite.

13. A nonwoven substrate as claimed in Claim 12, wherein said nonwoven substrate further comprises a superabsorbent material.

14. A nonwoven substrate as claimed in Claim 13, wherein said superabsorbent material is a superabsorbent fiber.

15. A nonwoven substrate as claimed in Claim 14, wherein said superabsorbent material is a component which is introduced before, during, or after the deposition of one or more highly attenuated meltblown components.

16. A nonwoven substrate as claimed in Claim 12, wherein said non woven substrate further comprises at least three component layers in relative surface orientation wherein a first component layer comprised of an integrating network of essentially continuous filaments forms one exterior planar surface, a second component layer comprised of an integrating network of essentially continuous filaments forms a second exterior planar surface opposite said first component layer, and at least one component layer comprised of highly attenuated meltblown filaments or filament fragments is positioned intermediate between the first and second exterior surface layers, wherein said first component surface layer exhibits a philic performance that is greater than said second component surface layer, and wherein said intermediate layer(s) exhibits a philic performance less than said first component surface layer and greater than said second component surface layer.