Method of applying a protein coating to a substrate and article thereof

What is claimed is:

1. A method of coating a permeable sheet with amphiphilic proteins, the method comprising the steps of:

providing a permeable sheet having a plurality of individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter;

providing an aqueous solution containing amphiphilic proteins, the solution having a surface tension of at least about 45 dynes per centimeter, and

contacting the solution containing amphiphilic proteins under shear stress conditions with the permeable sheet so that at least a portion of the amphiphilic proteins are adsorbed onto at least some individual exposed surfaces.

2. The method of claim 1, wherein the permeable sheet is a matrix of fibrous material.

3. The method of claim 1, wherein the matrix of fibrous material is selected from woven fabrics, knit fabrics and nonwoven fabrics.

4. The method of claim 1, wherein the permeable sheet is an apertured, film-like material.

5. The method of claim 1, wherein the apertured, film-like material is selected from perf-embossed films, textured apertured films, reticulated apertured films, contoured apertured films, film-nonwoven apertured laminates, and expanded plexi-filamentary films.

6. The method of claim 1, wherein the aqueous solution has an amphiphilic protein concentration of less than about 10 percent by weight.

7. The method of claim 1, wherein the aqueous solution has an amphiphilic protein concentration greater than about 0.01 to about 6 percent by weight.

8. The method of claim 1, wherein the aqueous solution is exposed to shear stress conditions characterized by a Reynold's number of at least about 200.

9. The method of claim 1, wherein the aqueous solution is exposed to shear stress conditions characterized by a Reynold's number of at least about 400.

10. The method of claim 1, wherein the aqueous solution is substantially a foam when contacted with the permeable sheet.

11. The method of claim 1, further comprising the step of washing the coated permeable sheet with an aqueous liquid having a relatively high surface tension.

12. The method of claim 1, further comprising the step of drying the coated permeable sheet material.

13. The method of claim 12, the treated material is dried utilizing infra-red radiation, yankee dryers, steam cans, microwaves, hot-air and/or through-air drying techniques, and ultrasonic energy.

14. The method of claim 11, wherein amphiphilic proteins are adsorbed onto at least some individual exposed surfaces thereby defining a patterned protein coating on the matrix of fibrous material.

15. The method of claim 1, further comprising the step of recontacting the solution containing amphiphilic proteins under shear stress conditions with the permeable sheet so that an additional portion of amphiphilic proteins are adsorbed onto at least some individual exposed surfaces.

16. The method of claim 1, wherein amphiphilic proteins are adsorbed onto a substantial portion of individual exposed surfaces having relatively low surface energies.

17. The method of claim 1, wherein the amphiphilic proteins adsorbed onto at least some individual exposed surfaces define a gradient distribution of amphiphilic protein coating along at least one dimension of the permeable sheet.

18. The method of claim 1, further comprising the step of adding one or more secondary materials to the coated permeable sheet.

19. A protein-coated permeable sheet comprising:

a permeable sheet having a plurality of individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter; and

amphiphilic proteins adsorbed onto at least some individual exposed surfaces to define a gradient distribution of amphiphilic protein coating along at least one dimension of the permeable sheet.

20. The protein-coated sheet of claim 19, wherein the gradient distribution of amphiphilic protein coating is along at least two dimensions of the permeable sheet.

21. The protein-coated sheet of claim 19, wherein the permeable sheet is a matrix of fibrous material.

22. The protein-coated sheet of claim 21, wherein the matrix of fibrous material is selected from woven fabrics, knit fabrics and nonwoven fabrics.

23. The protein-coated material of claim 22, wherein the nonwoven fabrics are selected from nonwoven webs of meltblown fibers, nonwoven webs of continuous spunbond filaments and bonded carded webs.

24. The protein-coated material of claim 23, wherein the nonwoven web of meltblown fibers further includes one or more secondary materials selected from the group consisting of textile fibers, wood pulp fibers, particulates and super-absorbent materials.

25. The protein-coated material of claim 21, wherein at least a portion of the fibrous material is a bi-component material selected from bi-component fibers and bi-component filaments.

26. The protein-coated sheet of claim 19, wherein the permeable sheet is an apertured, film-like material.

27. The protein-coated sheet of claim 26, wherein the apertured, film-like material is selected from perf-embossed films, textured apertured films, reticulated apertured films, contoured apertured films, film-nonwoven apertured laminates, and expanded plexi-filamentary films.

28. The protein-coated sheet of claim 19, wherein the permeable sheet further includes one or more secondary materials.

29. The protein-coated sheet of claim 19, wherein the permeable sheet is formed from a thermoplastic polymer.

30. The protein-coated sheet of claim 29, wherein the thermoplastic polymer comprises a polymer selected from polyolefins, polyamides and polyesters.

31. The protein-coated sheet of claim 30, wherein the polyolefin is selected from polyethylene, polypropylene, polybutene, ethylene copolymers, propylene copolymers, and butene copolymers and blends of the same.

32. The protein-coated sheet of claim 31 wherein the coated sheet has a critical surface tension of wetting greater than about 45 dynes per centimeter.

33. The protein-coated sheet of claim 32 wherein the coated sheet has a critical surface tension of wetting greater than about 50 dynes per centimeter.

34. The protein-coated sheet of claim 33 wherein the coated sheet has a critical surface tension of wetting greater than about 60 dynes per centimeter.

35. The protein-coated sheet of claim 19, wherein the protein-coated sheet has a basis weight of from about 6 to about 400 grams per square meter.

36. The protein-coated sheet of claim 19 wherein the amphiphilic proteins are adsorbed onto at least some individual exposed surfaces thereby defining a patterned protein coating on the permeable sheet.

37. The protein-coated sheet of claim 19 wherein the coating of amphiphilic proteins uniformly adsorbed onto individual exposed surfaces is present in only discrete portions of the sheet material.

38. The protein-coated sheet of claim 19 wherein the amphiphilic proteins are selected from the group consisting of globular proteins and random coil proteins.

39. The protein-coated sheet of claim 19 wherein the amphiphilic proteins are selected from milk proteins.

40. The protein-coated sheet of claim 19 wherein the amphiphilic proteins are selected from milk caseins.

41. The protein-coated sheet of claim 19 wherein the amphiphilic proteins are .beta.-casein.

42. The protein-coated sheet of claim 19 wherein coating of amphiphilic proteins comprises multiple layers.

43. The protein-coated sheet of claim 19 wherein the thickness of the protein coating ranges from about 1 nanometer to about 1 micron.

44. The protein-coated sheet of claim 43 wherein the thickness of the protein coating ranges from about 5 nanometers to about 900 nanometers.

45. A multilayer material comprising at least two layers of the protein-coated sheet of claim 19.

46. A multilayer material comprising at least one layer of the protein-coated sheet of claim 19 and at least one other layer.

47. The multilayer material of claim 46 wherein the other layer is selected from the group consisting of woven fabrics, knit fabrics, bonded carded webs, continuous spunbond filament webs, meltblown fiber webs, films, apertured films, and combinations thereof.

48. A protein-coated fibrous material comprising:

a matrix of fibrous material having individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter; and

amphiphilic proteins adsorbed onto at least some individual exposed surfaces to define a gradient distribution of amphiphilic protein coating along at least one dimension of the matrix of fibrous material.

49. A protein-coated film-like material comprising:

an apertured film-like material having individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter; and

amphiphilic proteins adsorbed onto at least some individual exposed surfaces to define a gradient distribution of amphiphilic protein coating along at least one dimension of the apertured film-like material.

50. A method of coating a permeable sheet with amphiphilic proteins at discrete locations, the method comprising the steps of:

providing a permeable sheet having a plurality of individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter;

providing an aqueous solution containing amphiphilic proteins, the solution having a surface tension of at least about 45 dynes per centimeter:,

contacting the solution containing amphiphilic proteins under shear stress conditions at discrete locations with the permeable sheet so that at least a portion of the amphiphilic proteins are adsorbed onto at least some individual exposed surfaces within the discrete locations; and

washing the coated fibrous material with a liquid to define a pattern of protein coating on the permeable sheet.

51. A method of coating a permeable sheet with amphiphilic proteins, the method comprising the steps of:

providing a permeable sheet having a plurality of individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter;

providing an aqueous solution containing amphiphilic proteins, the solution having a surface tension of at least about 45 dynes per centimeter; and

contacting the solution containing amphiphilic proteins under shear stress conditions with the permeable sheet so that at least a portion of the amphiphilic proteins are adsorbed onto at least some individual exposed surfaces to define a gradient distribution of amphiphilic protein coating along at least one dimension of the permeable sheet,

52. A protein-coated fibrous material comprising:

a matrix of fibrous polyolefin material having individual exposed surfaces, at least a portion of which having a surface energy of less than about 45 dynes per centimeter, and

amphiphilic proteins adsorbed onto at least some individual exposed surfaces to define a gradient distribution of amphiphilic protein coating along at least one dimension of the matrix of fibrous polyolefin material.

Description Submit all comments and votes

FIELD OF THE INVENTION

This invention relates to a method of applying a protein coating to a substrate. The invention also relates to a protein-coated substrate.

BACKGROUND OF THE INVENTION

Sheets of apertured films, woven fabrics and nonwoven materials are widely used in many types of products such as, for example, personal care products, garments, medical fabrics and the like. Some sheets made from certain inexpensive raw materials could have an even wider range of applications in these products if the sheets could be designed to have enhanced properties or attributes.

For example, polyolefins are widely used in the manufacture of sheets of apertured films, woven fabrics, and nonwoven materials. Many types of polyolefin sheets tend to be hydrophobic and relatively inert. That is, the low surface free energy of polyolefins (e.g., polypropylene) and their relatively chemically inert nature render many unmodified polyolefins ill-suited for providing attributes other than those based on hydrophobic interactions.

In the past, chemical coatings and/or internal additives have been added to sheets of materials to impart desired properties. Many of these coatings and/or additives present problems related to cost, effectiveness, durability and/or the environment.

It has been proposed that biofunctional materials (e.g., proteins) can be deposited from solutions onto different substrates (i.e., sheets of materials) to modify the surface properties of the substrates and/or serve as a functionalized surface that can be chemically reactive. However, many of the economically desirable substrates (e.g., substrates formed of polymers such as polyolefins) have surfaces that are unsuitable for the rapid and inexpensive deposition of biofunctional materials, especially when durable, tightly-bound coatings of satisfactory adherence are desired.

It has also been proposed that surfaces of these substrates can be modified to improve the adherence of biofunctional materials. Some suggested surface modification techniques involve: 1) irradiating the surface of a polymeric material in the presence of oxygen to create active sites and then chemically grafting a polymer onto the active sites; 2) providing an organic surface coating by plasma discharge in the presence of a plasma polymerizable, halogenated hydrocarbon gas; and 3) treating (e.g., oxidizing) the surface of a substrate so that it has a hydrophilic character with a high amount of cation-exchange groups.

Such treatments can be complex, expensive, environmentally unsuitable, leave trace amounts of undesirable compounds, unsuited for high-speed manufacturing processes, and/or cause degradation of the substrate. In particular, a trend toward increasing environmental awareness and government regulation in the areas of air, water, product and food quality make some of these treatments relatively unattractive. Furthermore, these treatments fail to address the need for a practical method of depositing a durable, tenacious coating of proteins on the unmodified surface (or surfaces) of a relatively inert, hydrophobic substrate.

Thus, there is still a need for a simple method of producing a durable and chemically reactive protein coating on an unmodified, relatively inert, hydrophobic substrate. A need exists for a practical method of producing a durable and chemically reactive protein coating on an unmodified, relatively inert, polyolefin substrate. A need exists for a pattern or gradient of surface modification on a relatively inert, hydrophobic substrate. There is also a need for a protein-coated fibrous and/or apertured film-like material having a protein coating such that the resulting coated material can generally be considered wettable. A need also exists for fibrous and/or apertured film-like substrates formed from a relatively inert, hydrophobic material (e.g., a polyolefin) that are coated with a readily available, inexpensive, natural, renewable and nontoxic material, especially if such a coated material can be produced in a high-speed manufacturing process. Meeting these needs are important since it is both economically and environmentally desirable to substitute relatively complex chemical surface modification and/or functionalization of inexpensive (and often recyclable) substrates with inexpensive, readily available natural materials.

DEFINITIONS

As used herein, the term "amphiphilic protein" refers to proteins having both hydrophobic regions and hydrophilic regions. For example, amphiphilic proteins may be selected from classes of globular and/or random coil proteins. As another example, amphiphilic proteins may be milk proteins. As a further example, amphiphilic proteins may include proteins such as those found in bovine milk including, but not limited to, various caseins and whey proteins.

As used herein, the term "relatively low surface energy" refers to surface energies (i.e., surface free energies) attributed to materials that are not generally considered to be water wettable. Generally speaking, such materials have a surface energy of less than about 45 dynes per centimeter (dynes/cm) as determined in accordance with critical surface tension of wetting techniques described by Bennet, M. K. and Zisman, W. A.; Relation of Wettability by Aqueous Solutions to the Surface Constitution of Low Energy Solids; J. Phys. Chem., pps. 1241-1246, Volume 63 (1959). Many such materials have a surface energy of ranging from about 29 to about 35 dynes/cm.

As used herein, the term "relatively high surface tension" refers to a level of attractive force in a liquid exerted by the molecules below the surface upon those at the surface/air interface, resulting from the high molecular concentration of a liquid compared to the low molecular concentration of a gas. Relatively high surface tensions are characteristic of, for example, some aqueous liquids and/or aqueous solutions having little or no added surfactants or other agents that reduce the surface tension. Surface tension may be determined from measurements of the contact angle of sessile drops using a goniometer such as, for example goniometer model No. 100-00 115 (equipped with videocamera) available from Rame-Hart, Inc., or by methods such as, for example, DuNouy ring methods. Relatively high surface tension for the purposes of the present invention is a surface tension of at least about 45 dynes/cm. Desirably, the surface tension is greater than 45 dynes/cm.

As used herein, the term "shear stress conditions" refers to conditions under which a shearing stress (force per unit area) is applied to a liquid. As an example, for a given volume of a liquid, increasing the rate at which the liquid penetrates or passes through a relatively permeable sheet such as, for example, a polyolefin nonwoven fibrous web (i.e., by decreasing the exposure time) results in an increased shear stress at the fiber/liquid interface. In this case, a long exposure time generally indicates little or no shear stresses and a short exposure time generally indicates shear stress conditions. Shear stress conditions may occur in liquid flow having generally laminar or turbulent flow characteristics.

As used herein, the term "adsorbed" refers to a type of adhesion which takes place at the surface of a solid in contact with another medium (e.g., a liquid), resulting in the accumulation or increased concentration of molecules from that medium in the immediate vicinity of the surface.

As used herein, the term "nonwoven web" refers to a web that has a structure of individual fibers or filaments which are interlaid, but not in an identifiable repeating manner. Nonwoven webs have been, in the past, formed by a variety of processes known to those skilled in the art such as, for example, meltblowing, spunbonding, wet-forming and various bonded carded web processes.

As used herein, the term "spunbonded web" refers to a web of small diameter fibers and/or filaments which are formed by extruding a molten thermoplastic material as filaments from a plurality of fine, usually circular, capillaries in a spinnerette with the diameter of the extruded filaments then being rapidly reduced, for example, by non-eductive or eductive fluid-drawing or other well known spunbonding mechanisms. The production of spunbonded nonwoven webs is illustrated in patents such as Appel, et al., U.S. Pat. No. 4,340,563.

As used herein, the term "meltblown fibers" means fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into a high-velocity gas (e.g. air) stream which attenuates the filaments of molten thermoplastic material to reduce their diameters, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high-velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. The meltblown process is well-known and is described in various patents and publications, including NRL Report 4364, "Manufacture of Super-Fine Organic Fibers" by V. A. Wendt, E. L. Boone, and C. D. Fluharty; NRL Report 5265, "An Improved Device for the Formation of Super-Fine Thermoplastic Fibers" by K. D. Lawrence, R. T. Lukas, and J. A. Young; and U.S. Pat. No. 3,849,241, issued Nov. 19, 1974, to Buntin, et al.

As used herein, the term "microfibers" means small diameter fibers having an average diameter not greater than about 100 microns, for example, having a diameter of from about 0.5 microns to about 50 microns, more specifically microfibers may also have an average diameter of from about 1 micron to about 20 microns. Microfibers having an average diameter of about 3 microns or less are commonly referred to as ultra-fine microfibers. A description of an exemplary process of making ultra-fine microfibers may be found in, for example, U.S. Pat. No. 5,213,881, entitled "A Nonwoven Web With Improved Barrier Properties".

As used herein, the term "apertured film-like material" refers to a generally flat or planar layer of material which has been punched, drilled, apertured, stretched, perforated, embossed, patterned, crinkled and/or otherwise processed so that it may have relatively gross or visible openings with or without a pattern or texture in the thickness dimension (i.e., Z-direction) of the material. Exemplary apertured film-like materials include, but are not limited to, perf-embossed films, textured apertured films, reticulated apertured films, contoured apertured films, film-nonwoven apertured laminates, and expanded plexi-filamentary films.

As used herein, the term "sheet" refers to a material that can be a woven fabric, knit fabric, nonwoven fabric or film-like material (e.g., an apertured film-like material).

As used herein, the term "solution" refers to any relatively uniformly dispersed mixture of one or more substances (e.g., solute) in one or more other substances (e.g., solvent). Generally speaking, the solvent may be a liquid such as, for example, water and/or mixtures of liquids. The solvent may contain additives such as salts, acids, bases, viscosity modifiers, preservatives, disinfectants, anti-microbial agents and the like. The solute may be any material adapted to uniformly disperse in the solvent at the appropriate level, (e.g., ionic level, molecular level, colloidal particle level or as a suspended solid). For example, a solution may be a uniformly dispersed mixture of ions, of molecules, of colloidal particles, or may even include mechanical suspensions.

As used herein, the terms "permeable" and "permeability" refer to the ability of a fluid, such as, for example, a gas to pass through a particular porous material. Permeability may be expressed in units of volume per unit time per unit area, for example, (cubic feet per minute) per square foot of material (e.g., (ft.sup.3 /minute/ft.sup.2)). Permeability may be determined utilizing a Frazier Air Permeability Tester available from the Frazier Precision Instrument Company and measured in accordance with Federal Test Method 5450, Standard No. 191A, except that the sample size was 8".times.8" instead of 7".times.7". Although permeability is generally expressed as the ability of air or other gas to pass through a permeable sheet, sufficient levels of gas permeability may correspond to levels of liquid permeability to enable the practice of the present invention. For example, a sufficient level of gas permeability may allow an adequate level of liquid to pass through a permeable sheet with or without assistance of a driving force such as, for example, an applied vacuum or applied gas pressure. Generally speaking, a permeable sheet may have a permeability of at least about 20 cubic feet per minute per square foot (cfm/ft.sup.2), as measured for a substantially dry sheet prior to processing. It is contemplated that a sheet having a permeability of less than about 20 cfm/ft.sup.2, as measured for a substantially dry sheet prior to processing, could be used successfully in the practice of the present invention with (or in some cases without) assistance of a driving force such as, for example, an applied vacuum or applied gas pressure. As an example, a permeable sheet may have a permeability of from about 25 to over 200 cfm/ft.sup.2, as measured for a substantially dry sheet prior to processing. As another example, a permeable sheet may have a permeability of from about 35 to about 150 cfm/ft.sup.2, as measured for a substantially dry sheet prior to processing.

As used herein, the term "superabsorbent" refers to absorbent materials capable of absorbing at least 10 grams of aqueous liquid (e.g. water, saline solution or synthetic urine Item No. K-C 399105 available from PPG Industries) per gram of absorbent material while immersed in the liquid for 4 hours and holding the absorbed liquid while under a compression force of up to about 1.5 pounds per square inch.

As used herein, the term "consisting essentially of" does not exclude the presence of additional materials which do not significantly affect the desired characteristics of a given composition or product. Exemplary materials of this sort would include, without limitation, pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, particulates or materials added to enhance processability of a composition.

SUMMARY OF THE INVENTION

The problems described above are addressed by the present invention which is directed to a method of coating a permeable sheet with amphiphilic proteins. The method includes the steps of: 1) providing a permeable sheet having a plurality of individual exposed surfaces, at least a portion of which having relatively low surface energies; 2) providing an aqueous solution containing amphiphilic proteins, the solution having a relatively high surface tension; and 3) contacting the solution containing amphiphilic proteins under shear stress conditions with the permeable sheet so that at least a portion of the amphiphilic proteins are adsorbed onto at least some individual exposed surfaces.

The permeable sheet may be a matrix of fibrous material. The matrix of fibrous material may be, but is not limited to, one or more woven fabrics, knit fabrics, nonwoven fabrics and combinations of the same. The matrix of fibrous material may further include one or more secondary materials.

The matrix of fibrous material may be a nonwoven fabric such as, for example, nonwoven webs of meltblown fibers, nonwoven webs of continuous spunbond filaments and bonded carded webs. In an embodiment of the invention, the nonwoven web of meltblown fibers may further include one or more secondary materials selected from the group consisting of textile fibers, wood pulp fibers, particulates and superabsorbent materials.

The fibrous material may be formed from a thermoplastic polymer. For example, thermoplastic polymer may be selected from polyolefins, polyamides and polyesters. The polyolefin may be selected from polyethylene, polypropylene, polybutene, ethylene copolymers, propylene copolymers, and butene copolymers and blends of the same.

In one aspect of the invention, at least a portion of the fibrous material may be a multi-component or bi-component material selected from multi-component or bi-component fibers and multi-component or bi-component filaments. It is contemplated that at least a portion, if not all, of these fibers may be textured by use of an expanding agent.

The permeable sheet may be an apertured, film-like material. The apertured, film-like material may include, but is not limited to perf-embossed films, one or more textured apertured films, reticulated apertured films, contoured apertured films, film-nonwoven apertured laminates, expanded plexi-filamentary films and combination of the same. The apertured film-like material may further include one or more secondary materials.

The apertured film-like material may be formed from a thermoplastic polymer. For example, the thermoplastic polymer may be selected from polyolefins, polyamides and polyesters. If the polymer is a polyolefin, it may be selected from polyethylene, polypropylene, polybutene, ethylene copolymers, propylene copolymers, and butene copolymers and blends of the same. The permeable sheet may be composed of combinations of one or more matrices of fibrous material and apertured, film-like material.

According to the present invention, the aqueous solution may have an amphiphilic protein concentration of less than about 10 percent by weight. Desirably, the aqueous solution has an amphiphilic protein concentration greater than about 0.01 up to about 6 percent by weight.

In an aspect of the present invention, the aqueous solution may be exposed to shear stress conditions such that it has a Reynold's number of at least about 200. For example, the aqueous solution may be exposed to shear stress conditions such that it has a Reynold's number of at least about 400. In another aspect of the invention, the aqueous solution may be in the form of a foam (i.e., a colloidal system of gas dispersed in a liquid) when contacted with the matrix of fibrous material.

The method of the present invention may further include the step of washing or rinsing the coated permeable sheet with an aqueous liquid having a relatively high surface tension. The method of the present invention may further include the step of drying the coated permeable sheet. For example, the material treated as described above may be dried using infra-red radiation, yankee dryers, steam cans, microwaves, hot-air and/or through-air drying techniques, and ultrasonic energy.

The method of the present invention may further include the step of recontacting a solution containing amphiphilic proteins under shear stress conditions with the permeable sheet so that an additional portion of amphiphilic proteins are adsorbed onto at least some individual exposed surfaces.

In the practice of the present invention amphiphilic proteins may be adsorbed onto at least some individual exposed surfaces thereby defining a patterned protein coating on the permeable sheet. The present invention also encompasses a method wherein amphiphilic proteins are adsorbed onto a substantial portion of individual exposed surfaces having relatively low surface energies to define a relatively uniform coating. In another aspect of the invention, amphiphilic proteins may be adsorbed onto at least some individual exposed surfaces to define a gradient distribution of amphiphilic protein coating along at least one dimension of the permeable sheet.

The method of the present invention further includes the step of adding one or more secondary materials to the coated permeable sheet. For example, the secondary materials may include particulates and or fibrous material. Suitable fibrous material may include pulp, synthetic and/or natural fibers and the like. Suitable particulate material may include activated carbon, zeolites, clays, superabsorbent particulates and the like.

The present invention encompasses a