Filtering composite material

Abstract

The present disclosure describes a filtration composite comprising multiple layers of filtration media. In some embodiments, the filtration composite is preferably glass-free or substantially glass-free. When the composite is glass-free or substantially glass-free, the composite preferably exhibits capacity and efficiency comparable to or better than similar glass-containing filtration media. The composite comprises: a first nonwoven filtration medium comprising bicomponent fibers, efficiency fibers having a fiber diameter in the range of 1 micrometer to 5 micrometers, and microfibillated fibers; an optional second nonwoven filtration medium; and a third nonwoven filtration medium comprising efficiency fibers having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 004,926, filed April 3, 2020, and U.S. Provisional Application No. 63 / 081,159, filed September 21, 2020, the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] Filter media, such as those used for fuel filtration, typically include glass microfibers. However, there are concerns that during certain types of filtration, glass microfibers may be released from the filter media, causing environmental pollution, or, in the case of fuel filtration, causing damage to the internal combustion engine. Summary of the Invention

[0004] This disclosure describes composite materials comprising multiple layers of filter media, methods for manufacturing these composite materials, and methods for using these composite materials. These compositions are preferably substantially glass-free or glass-free and exhibit capacity and efficiency comparable to or better than similar glass-containing filter media.

[0005] In one aspect, this disclosure describes a composite material comprising a first nonwoven filter medium; optionally, a second nonwoven filter medium; and a third nonwoven filter medium. The composite material is substantially free of glass fibers. The first nonwoven filter medium comprises 40 wt% to 90 wt% of a first bicomponent fiber having a fiber diameter in the range of 5 micrometers to 50 micrometers and a fiber length in the range of 0.1 cm to 15 cm; 0 wt% to 25 wt% of a first high-efficiency fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers; and 10 wt% to 60 wt% of a first microfibrillated fiber, wherein a majority of the microfibrillated fiber has a transverse dimension of a maximum of 4 micrometers. The optional second nonwoven filter medium comprises 40 wt% to 90 wt% of a second bicomponent fiber having a fiber diameter in the range of 5 micrometers to 50 micrometers and a fiber length of 0.1 cm to 15 cm; 0 wt% to 25 wt% of a second high-efficiency fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers; and 10 wt% to 60 wt% of a second microfibrillated fiber, wherein most of the microfibrillated fiber has a transverse dimension of up to 4 micrometers. The third nonwoven filter medium comprises small-efficiency fibers having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer.

[0006] In some embodiments, the structural polymer portion of the bicomponent fiber has a melting point of at least 240°C, and the adhesive polymer portion of the bicomponent fiber has a melting point in the range of 100°C to 190°C.

[0007] In some embodiments, the first high-efficiency fiber comprises polyethylene terephthalate (PET), the second high-efficiency fiber comprises PET, or both the first high-efficiency fiber and the second high-efficiency fiber comprise PET.

[0008] In some embodiments, the small-efficiency fiber has a fiber diameter in a range of 0.6 microns to 0.8 microns.

[0009] In some embodiments, the small-efficiency fiber comprises polyethylene terephthalate (PET).

[0010] In some embodiments, the composite material is substantially free of resin.

[0011] In some embodiments, the composite material is free of glass fibers.

[0012] In some embodiments, the first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium are discrete layers.

[0013] In some embodiments, the nonwoven filter medium is configured to pass a liquid through the first nonwoven filter medium, then through the second nonwoven filter medium, and then through the third nonwoven filter medium.

[0014] In some embodiments, the nonwoven filter medium further comprises a support layer. The third nonwoven filter medium can be in contact with the support layer.

[0015] In some embodiments, the microfibrillated fiber comprises microfibrillated cellulose fiber.

[0016] In another aspect, the disclosure describes a method of filtering a liquid stream, the method comprising passing a liquid stream comprising a contaminant through a composite material as described herein and removing the contaminant from the liquid stream. The liquid stream can comprise air.

[0017] In another aspect, the disclosure describes a method of manufacturing a composite material as described herein, the method comprising independently manufacturing the first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium.

[0018] As used herein, micron is equivalent to micrometer (pm).

[0019] As used herein, a "fiber" has an aspect ratio (i.e., a ratio of length to transverse dimension) of greater than 3: 1, and preferably greater than 5: 1. For example, glass fibers typically have an aspect ratio of greater than 100: 1. In this context, the "transverse dimension" is the width (in two dimensions) or diameter (in three dimensions) of the fiber. The term "diameter" refers either to the diameter of a circular cross-section of the fiber, or to the largest cross-sectional dimension of a non-circular cross-section of the fiber. The fiber length can be finite or infinite, depending on the desired outcome.

[0020] As used herein, the "beta ratio" or "beta" is the ratio of upstream to downstream particles under steady flow conditions (ISO 16889:2008) as described in the Examples. The higher the filter efficiency, the higher the beta ratio. The beta ratio is defined as follows:

[0021]

[0022] where N d,U is the count of upstream particles per unit fluid volume of particles having a diameter of d or greater, and N d,D is the count of downstream particles per unit fluid volume of particles having a diameter of d or greater. If present, the subscript (e.g., d) attached to beta indicates the particle size for which the ratio is being reported.

[0023] As used herein, the term "substantially free of" indicates that the filtration medium does not contain an amount of the listed component (e.g., glass fibers or resin) that contributes in any material way to the activity or action of the filtration medium. The term is intended to include the inclusion of trace components that do not provide any material contribution to the filtration properties of the filtration medium. For example, a filtration medium that is substantially free of glass can include less than 1 wt% glass fibers. For example, a filtration medium that is substantially free of resin can include less than 5 wt% resin.

[0024] As used herein, the term "free of" indicates that the filtration medium does not contain an amount of the listed component (e.g., glass fibers or resin). For example, a "free of glass" filtration medium does not include any glass, and a "free of resin" medium does not include any resin.

[0025] Unless otherwise indicated, any reference to a standard method (e.g., ASTM, TAPPI, etc.) refers to the most recent available version of that method at the time of filing of this disclosure.

[0026] The words "preferred" and "preferably" mean that under some circumstances one or more embodiments of the application can provide certain benefits. However, other embodiments can also be preferred under the same or other circumstances. In addition, the terms "preferred embodiment" and "preferred embodiments" do not mean that a

[0027] Where the term "comprising," or variations such as "comprise" or "comprises," or "include," or variations such as "includes," or "including," are used in the specification, these terms are to be interpreted as encompassing the presence of stated steps or elements, but not excluding the presence of other steps or elements.

[0028] "Consisting of means including and limited to any of the contents included in the phrase "consisting of." Thus, the phrase "consisting of indicates that the listed elements are required or mandatory, and that no other elements can be present. "Substantially consisting of means including any of the elements listed in the phrase, and limited to other elements that do not materially affect or substantially contribute to the function or action specified in this disclosure for the listed elements. Thus, the phrase "substantially consisting of indicates that the listed elements are required or mandatory, but that other elements are optional and can or can not be present, depending on whether they materially affect or substantially contribute to the function or action of the listed elements.

[0029] "An," "the," and "at least one" are used interchangeably, and mean one or more than one, unless otherwise indicated.

[0030] As used herein, the term "or" is generally employed in its usual sense, including "and / or," unless the context clearly indicates otherwise.

[0031] The term "and / or" means one or all of the listed elements or a combination of any two or more of the listed elements.

[0032] Also herein, recitation of ranges of values includes all values within the range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0033] In this document, "up to" a certain number (e.g., up to 50) includes the number (e.g., 50).

[0034] The term "in the range / within a range" (and similar statements) includes the endpoints of the stated range.

[0035] For any method disclosed herein that includes discrete steps, the steps can be carried out in any feasible order. Also, depending on the context, any combination of two or more steps can be carried out simultaneously or concurrently.

[0036] All headings are for the convenience of the reader and are not to be used in the interpretation of the meaning of the text of the specification.

[0037] References throughout this specification to "one embodiment," "an embodiment," "certain embodiments," or "some embodiments," etc., mean that a particular feature, structure, composition, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of such phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, composition, or characteristic is described in one or more embodiments, it is submitted that it can be combined with one or more other particular features, structures, compositions, or characteristics described in any suitable combination.

[0038] Unless otherwise stated, all numbers expressing quantities of components, molecular weights, etc. used in the specification and claims are to be understood as being modified in all instances by the term "about." As used herein, the term "about" in connection with a measured quantity means the quantity ± / of the quantity as expected by one of ordinary skill in the art in light of the measurement precision asserted in the disclosure and the inherent errors associated with that quantity. Accordingly, unless otherwise indicated, the numerical parameters set forth in the specification and claims are approximations. At the very least, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. It is also possible, however, that an entirety of a particular numerical parameter is intentionally set forth by the language of the specification and / or claims to convey that the precision of the value is a specific aspect of the disclosure.

[0039] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0040] The above summary of the present application is not intended to describe each disclosed embodiment or every implementation of the present application. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used individually or in various combination. In each instance, the list of examples is not meant to be exclusive or exhaustive. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1A Load capacity of a composite material prepared as described in Example 1 is shown. Figure 1B Efficiency of a composite material including a fine fiber layer prepared as described in Example 1 is shown.

[0042] Figure 2A A schematic of an exemplary composite material, which in some embodiments can be prepared as described in Example 1, is shown. Figure 2B A schematic of an exemplary composite material is shown. Figure 2C A schematic of an exemplary composite material, which in some embodiments can be prepared as described in Example 2, is shown. DETAILED DESCRIPTION

[0043] The present disclosure describes composites comprising multiple layers of filtration media, methods of making these composites, and methods of using these composites. These compositions are preferably substantially glass-free or glass-free and exhibit capacities and efficiencies comparable to or better than similar glass-containing filtration media.

[0044] Composite

[0045] In an aspect, the present disclosure describes a composite comprising a plurality of nonwoven filtration media. In some embodiments, each nonwoven filtration medium is preferably substantially glass-free or glass-free.

[0046] The composite comprises a first nonwoven filtration medium, an optional second nonwoven filtration medium, and a third nonwoven filtration medium. The first nonwoven filtration medium includes first bicomponent fibers; first large efficiency fibers having a fiber diameter in the range of 1 micrometer to 5 micrometers; and first microfibillated fibers. The second nonwoven filtration medium, if present, includes second bicomponent fibers; second large efficiency fibers having a fiber diameter in the range of 1 micrometer to 5 micrometers; and second microfibillated fibers. The third nonwoven filtration medium comprises small efficiency fibers having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer. As used herein, “large efficiency fibers” are fibers having a fiber diameter in the range of 1 micrometer to 5 micrometers. As used herein, “small efficiency fibers” are fibers having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer.

[0047] In some embodiments, the small efficiency fibers preferably include polyethylene terephthalate (PET). In some embodiments, the first large efficiency fibers preferably include PET. In some embodiments, the second large efficiency fibers preferably include PET.

[0048] In some embodiments, one or more of the fibers of the composite or the layers of the composite can be selected or treated to alter the electrostatic charge of the medium. The charge typically includes a layer of positive or negative charges trapped at or near the surface of the polymer, or a cloud of charges stored in the bulk of the polymer. The charge can also include polarized charges that are frozen in when the dipoles of the molecules align. Methods of subjecting materials to charges are well known to those skilled in the art. These methods include, for example, thermal methods, liquid contact methods, electron beam methods, plasma methods, and corona discharge methods.

[0049] In some embodiments, the composite further comprises a support layer.

[0050] In some embodiments, the first nonwoven filter medium, the optional second nonwoven filter medium (if present), and the third nonwoven filter medium are discrete layers. That is, there is no gradient between the first nonwoven filter medium and the second nonwoven filter medium or between the second nonwoven filter medium and the third nonwoven filter medium. If the second nonwoven filter medium is not present, there is no gradient between the first nonwoven filter medium and the third nonwoven filter medium.

[0051] In some embodiments, the first nonwoven filter medium is in contact with the second nonwoven filter medium, and the second nonwoven filter medium is in contact with the third nonwoven filter medium. When the composite further comprises a support layer, the third nonwoven filter medium can be in contact with the support layer.

[0052] In some embodiments, the composite is configured to pass a liquid through the first nonwoven filter medium, then through the second nonwoven filter medium, and then through the third nonwoven filter medium.

[0053] In some embodiments, when the composite comprises a support layer, the composite is configured to pass a liquid through the first nonwoven filter medium, then through the second nonwoven filter medium, then through the third nonwoven filter medium, and then through the support layer.

[0054] In some embodiments, the first nonwoven filter medium is in contact with the third nonwoven filter medium. When the composite further comprises a support layer, the third nonwoven filter medium can be in contact with the support layer.

[0055] In some embodiments, the composite is configured to pass a liquid through the first nonwoven filter medium, then through the third nonwoven filter medium. When the composite further comprises a support layer, the composite is configured to pass a liquid through the first nonwoven filter medium, then through the third nonwoven filter medium, and then through the support layer.

[0056] In some embodiments, the composite is substantially free of resin. In some embodiments, the composite does not comprise resin.

[0057] The composite is substantially free of glass (including, for example, glass fibers). In some embodiments, the composite does not comprise glass.

[0058] In exemplary embodiments, the composite comprises a first nonwoven filter medium, an optional second nonwoven filter medium, and a third nonwoven filter medium. The first nonwoven filter medium comprises: 40 wt% to 90 wt% of first bicomponent fibers having a fiber diameter in the range of 5 microns to 50 microns and a fiber length of 0.1 cm to 15 cm; 0 wt% to 25 wt% of first large efficiency fibers; and 10 wt% to 60 wt% of first microfibillated fibers, wherein a majority of the microfibillated fibers have a transverse dimension of at most 4 microns. The optional second nonwoven filter medium comprises: 40 wt% to 90 wt% of second bicomponent fibers having a fiber diameter in the range of 5 microns to 50 microns and a fiber length of 0.1 cm to 15 cm; 0 wt% to 25 wt% of second large efficiency fibers; and 10 wt% to 60 wt% of second microfibillated fibers, wherein a majority of the microfibillated fibers have a transverse dimension of at most 4 microns. The third nonwoven filter medium comprises small efficiency fibers.

[0059] Figure 2C An exemplary embodiment is shown in FIG. 1.

[0060] As described in Example 1, the addition of a layer of electrospun fine fibers of 1 pm diameter to a composite filter medium increased the efficiency of the composite compared to a composite without a fine fiber layer. As further described in Example 2 and as shown in FIG. 2, the fine fiber layer can be replaced by a layer comprising small efficiency fine fibers, and the resulting composite is expected to have similar efficiency as the composite comprising a fine fiber layer. Figure 2C

[0061] The results of Example 1 are unexpected because it has been previously reported that creating an interface between layers of media is undesirable and that, instead, a gradient structure should be pursued. (See, e.g., U.S. Pub. No. 2014 / 0360145.) Without wishing to be bound by theory, it is believed that creating an interface between layers of media, including, for example, a layer of nonwoven filter medium comprising a layer of small efficiency fine fibers and a layer of filter medium that acts as a loading layer, can allow for higher efficiency than using a gradient structure because the non-uniformity of each layer is not consistent throughout the depth of the media.

[0062] The first and second nonwoven filter media

[0063] The first nonwoven filter medium and the optional second nonwoven filter medium, if present, each comprise bicomponent fibers, large efficiency fibers having a fiber diameter in the range of 1 micron to 5 microns, and microfibillated fibers.

[0064] In some embodiments, either or both of the first and second nonwoven filter media act as a loading layer, i.e., a filter medium that distributes locations of collection of contaminants throughout the depth of the media. Figure 2C ​Exemplary embodiments in which both the first and second nonwoven filter media serve as a loading layer are described. Figure 2B Exemplary embodiments in which the second nonwoven filter media is not included are shown.

[0065] In some embodiments, either or both of the first and second nonwoven filter media has a solidity of at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, or at least 10%. In some embodiments, the nonwoven filter media has a solidity of at most 5%, at most 6%, at most 7%, at most 8%, at most 9%, at most 10%, at most 11%, at most 12%, at most 13%, at most 14%, at most 15%, at most 16%, at most 17%, at most 18%, at most 19%, or at most 20%. In exemplary embodiments, the first nonwoven filter media has a solidity in the range of 5% to 15%. In exemplary embodiments, the second nonwoven filter media has a solidity in the range of 5% to 15%. In some embodiments, the solidity is preferably measured as described in the Examples.

[0066] In some embodiments, either or both of the first and second nonwoven filter media has a basis weight of at least 20 g / m2 2 , at least 24 g / m2 2 , at least 25 g / m2 2 , at least 30 g / m2 2 , at least 35 g / m2 2 , at least 40 g / m2 2 , at least 50 g / m2 2 , at least 60 g / m2 2 , or at least 70 g / m2 2 . In some embodiments, the nonwoven filter media has a basis weight of at most 25 g / m2 2 , at most 30 g / m2 2 , at most 35 g / m2 2 , at most 40 g / m2 2 , at most 50 g / m2 2 , at most 60 g / m2 2 , at most 70 g / m2 2 , at most 75 g / m2 2 , at most 80 g / m2 2 , at most 85 g / m2 2 , at most 90 g / m2 2 , at most 95 g / m2 2 , at most 100 g / m2 2 , or at most 105 g / m2 2 . In exemplary embodiments, the first nonwoven filter media has a basis weight in the range of 24 g / m22 to 100 g / m 2 In example embodiments, the second nonwoven filter medium has a basis weight in the range of 24 g / m 2 to 100 g / m 2 In some embodiments, the basis weight is preferably measured using ASTM D646-13.

[0067] In some embodiments, either or both of the first and second nonwoven filter media has a pore size of at least 0.5 microns, at least 1 micron, at least 1.5 microns, at least 2 microns, at least 3 microns, at least 5 microns, or at least 10 microns. In some embodiments, the nonwoven filter medium has a pore size of at most 5 microns, at most 10 microns, at most 15 microns, or at most 20 microns. In example embodiments, the first nonwoven filter medium has a pore size in the range of 0.5 microns to 20 microns. In example embodiments, the second nonwoven filter medium has a pore size in the range of 0.5 microns to 20 microns. In another example embodiment, the first nonwoven filter medium has a pore size in the range of 2 microns to 15 microns. In another example embodiment, the second nonwoven filter medium has a pore size in the range of 2 microns to 15 microns. As used herein, pore size refers to the mean flow pore size, as calculated as described in ASTM F316-03.

[0068] In some embodiments, either or both of the first and second nonwoven filter media has a thickness of at least 0.1 mm, at least 0.12 mm, at least 0.15 mm, or at least 0.2 mm. In some embodiments, the nonwoven filter medium has a thickness of at most 0.2 mm, at most 0.4 mm, at most 0.5 mm, at most 0.7 mm, or at most 1 mm. In example embodiments, the first nonwoven filter medium has a thickness in the range of 0.12 mm to 1 mm. In example embodiments, the second nonwoven filter medium has a thickness in the range of 0.12 mm to 1 mm. In some embodiments, the thickness of the filter medium is preferably measured according to TAPPI T411 om-15 test method using a foot pressure of 1.5 psi.

[0069] In some embodiments, either or both of the first and second nonwoven filter media has a flow rate of at least 1 ft 3 / ft 2 / min at 0.5 inches of water, at least 5 ft 3 / ft 2 / min at 0.5 inches of water, or at least 10 ft 3 / ft 2permeability of 1 ft 3 / ft 2 / min, a permeability of 20 ft 3 / ft 2 / min, a permeability of 50 ft 3 / ft 2 / min, a permeability of 75 ft 3 / ft 2 / min, or a permeability of 100 ft 3 / ft 2 / min. In exemplary embodiments, the first nonwoven filter medium has a permeability ranging from 1 ft 3 / ft 2 / min to 100 ft 3 / ft 2 / min. In exemplary embodiments, the second nonwoven filter medium has a permeability ranging from 1 ft 3 / ft 2 / min to 100 ft 3 / ft 2 / min. In another exemplary embodiment, the first nonwoven filter medium has a permeability ranging from 10 ft 3 / ft 2 / min to 75 ft 3 / ft 2 / min. In another exemplary embodiment, the second nonwoven filter medium has a permeability ranging from 10 ft 3 / ft 2 / min to 75 ft 3 / ft 2 / min. In some embodiments, the air permeability is preferably measured according to ASTM D737-18.

[0070] In some embodiments, either or both of the first and second nonwoven filter media are substantially free of resin. In some embodiments, either or both of the first and second nonwoven filter media do not include resin.

[0071] In some embodiments, either or both of the first and second nonwoven filter media are substantially free of glass fibers. In some embodiments, either or both of the first and second nonwoven filter media do not include glass fibers.

[0072] Bicomponent fibers

[0073] The first and second filtration media each include bicomponent fibers. Any suitable bicomponent fiber can be used for each medium, and the bicomponent fibers can be selected according to the intended use of the medium.

[0074] In some embodiments, each of the first and second filtration media includes at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, or at least 70 wt% bicomponent fibers. In some embodiments, each of the first and second filtration media includes at most 30 wt%, at most 35 wt%, at most 40 wt%, at most 45 wt%, at most 50 wt%, at most 55 wt%, at most 60 wt%, at most 65 wt%, at most 70 wt%, at most 75 wt%, at most 80 wt%, at most 85 wt%, at most 90 wt% bicomponent fibers. In an exemplary embodiment, the first filtration medium includes 40 wt% to 90 wt% bicomponent fibers. In an exemplary embodiment, the second filtration medium includes 40 wt% to 90 wt% bicomponent fibers. In another exemplary embodiment, the first filtration medium includes 40 wt% to 75 wt% bicomponent fibers. In an exemplary embodiment, the second filtration medium includes 40 wt% to 75 wt% bicomponent fibers.

[0075] In some embodiments, the bicomponent fibers have a fiber diameter of at least 1 micron, at least 5 microns, at least 10 microns, at least 15 microns, or at least 20 microns. In some embodiments, the bicomponent fibers have a fiber diameter of at most 5 microns, at most 10 microns, at most 15 microns, at most 20 microns, at most 25 microns, at most 30 microns, at most 35 microns, at most 40 microns, at most 45 microns, or at most 50 microns. In an exemplary embodiment, the bicomponent fibers have a fiber diameter in a range of 5 microns to 50 microns. In another exemplary embodiment, the bicomponent fibers have a fiber diameter in a range of 5 microns to 25 microns. In another exemplary embodiment, the bicomponent fibers have a fiber diameter of 14 microns.

[0076] In some embodiments, the bicomponent fibers have a fiber length of at least 0.1 cm, at least 0.5 cm, or at least 1 cm. In some embodiments, the bicomponent fibers have a fiber length of at most 0.5 cm, at most 1 cm, at most 5 cm, at most 10 cm, or at most 15 cm. In an exemplary embodiment, the bicomponent fibers have a fiber length in a range of 0.1 cm to 15 cm. In another exemplary embodiment, the bicomponent fibers have a fiber length of 6 mm.

[0077] In some embodiments, the bicomponent fiber includes a structural polymer portion and a thermoplastic binder polymer portion, the structural polymer portion having a higher melting point than the melting point of the binder polymer portion.

[0078] The structural polymer portion and the binder polymer portion can be made of any suitable material. For example, the structural polymer portion can include PET, and the binder polymer portion can include coPET. In further examples, the structural polymer portion can include PET, and the binder polymer portion can include polyethylene (PE), PET, nylon, polypropylene (PP), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyphenylene sulfide (PPS), meta-aramid, or para-aramid. In further examples, the binder polymer portion can include polyethylene (PE), polylactic acid (PLA), nylon, ethylene-vinyl alcohol (EVOH), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF) (e.g., Kynar®), or any other polymer or modified polymer designed to have a lower melting temperature than the core structural polymer. YNAR

[0079] In some embodiments, the structural polymer portion is a core of the bicomponent fiber, and the thermoplastic binder polymer portion is a sheath of the bicomponent fiber.

[0080] In some embodiments, the structural polymer portion of the bicomponent fiber has a melting point of at least 240 °C, and the binder polymer portion of the bicomponent fiber has a melting point of at most 115 °C. An exemplary bicomponent fiber in which the structural polymer portion has a melting point of at least 240 °C and the binder polymer portion has a melting point of at most 115 °C is 271P, a 14 pm diameter fiber available from Advansa (Hamm, Germany).

[0081] In some embodiments, the structural polymer portion of the bicomponent fiber has a melting point of at least 240 °C, and the binder polymer portion of the bicomponent fiber has a melting point in the range of 100 °C to 190 °C. In one exemplary embodiment, the structural polymer portion of the bicomponent fiber has a melting point of at least 240 °C, and the binder polymer portion of the bicomponent fiber has a melting point in the range of 120 °C to 170 °C. In another exemplary embodiment, the structural polymer portion of the bicomponent fiber has a melting point of at least 240 °C, and the binder polymer portion of the bicomponent fiber has a melting point in the range of 140 °C to 160 °C.

[0082] ​Exemplary bicomponent fibers (where the structural polymer portion has a melting point of at least 240°C and the binder polymer portion has a melting point in the range of 100°C to 190°C) are TJ04CN (with a binder polymer portion melting point of 110°C), TJ04BN (with a binder polymer portion melting point of 150°C), both available from Teijin Fibers Limited of Osaka, Japan; 271P (with a binder polymer portion melting point of 110°C), available from Advansa, Hamm, Germany; and T-202 or T-217 (each with a binder polymer portion melting point of 180°C), both available from Fiber Innovation Technology, Inc. of Johnson City, TN.

[0083] In some embodiments, the first bicomponent fiber and the second bicomponent fiber can include two different bicomponent fibers or two different combinations of bicomponent fibers. In exemplary embodiments, the bicomponent fibers can include a first bicomponent fiber (where the structural portion has a melting point of at least 240°C and the binder polymer portion has a melting point of at most 115°C) and a second bicomponent fiber (where the structural polymer portion has a melting point of at least 240°C and the binder polymer portion has a melting point in the range of 100°C to 190°C). For example, the bicomponent fibers can include Advansa 271P and TJ04BN.

[0084] High efficiency fibers

[0085] The first and second filter media can each include“high efficiency fibers,” where“high efficiency fibers” as used herein are fibers having a fiber diameter in the range of 1 micron to 5 microns. In some embodiments, one or both of the first and second filter media do not include high efficiency fibers.

[0086] In some embodiments, the high efficiency fibers are preferably PET fibers. In some embodiments, the high efficiency fibers can consist essentially of PET. In some embodiments, the high efficiency fibers can consist of PET.

[0087] Additionally or alternatively, the low efficiency fibers can include nylon, acryl, rayon, polypropylene, polyethylene, ethylene-vinyl alcohol (EVOH), polylactic acid (PLA), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), or other suitable meltable polymers.

[0088] In some embodiments, each of the first and second filtration media includes at least 0 wt%, at least 0.1 wt%, at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, or at least 25 wt% of large efficiency fibers. In some embodiments, each of the first and second filtration media includes at most 15 wt%, at most 20 wt%, or at most 25 wt% of large efficiency fibers. In an exemplary embodiment, the first filtration media includes 0 wt% to 25 wt% of large efficiency fibers. In an exemplary embodiment, the second filtration media includes 0 wt% to 25 wt% of large efficiency fibers. In another exemplary embodiment, the first filtration media includes 10 wt% to 25 wt% of large efficiency fibers. In another exemplary embodiment, the second filtration media includes 10 wt% to 25 wt% of large efficiency fibers.

[0089] In some embodiments, the large efficiency fibers have a fiber diameter of at least 1 micron, at least 1.5 microns, at least 2 microns, at least 3 microns, or at least 4 microns. In some embodiments, the large efficiency fibers have a fiber diameter of at most 1.5 microns, at most 2 microns, at most 3 microns, at most 4 microns, or at most 5 microns. For example, in an exemplary embodiment, the large efficiency fibers have a fiber diameter in a range of 2 microns to 4 microns. In another exemplary embodiment, the large efficiency fibers have a fiber diameter of 2.7 microns. In a further exemplary embodiment, the large efficiency fibers have a fiber diameter of 2.5 microns.

[0090] In an example, the large efficiency fibers include PET and have a fiber diameter of 2.7 microns.

[0091] In some embodiments, the large efficiency fibers have a length of at least 0.5 mm, at least 1 mm, or at least 1.5 mm. In some embodiments, the large efficiency fibers have a length of at most 10 mm, at most 11 mm, at most 12 mm, or at most 15 mm. In an exemplary embodiment, the large efficiency fibers have a length in a range of 1 mm to 15 mm. In a further exemplary embodiment, the large efficiency fibers have a length in a range of 1 mm to 12 mm.

[0092] In some embodiments, when the large efficiency fibers include PET, the PET has a melting point of at least 250 °C, more preferably at least 275 °C, even more preferably at least 290 °C.

[0093] Microfibillated fibers

[0094] The first and optional second filtration media each include microfibillated fibers. As used herein, microfibillated fibers are fibers that have been processed to produce fibers with a higher surface area, branched structure than the unprocessed fibers.

[0095] In some embodiments, the microfibrillated fiber may be a microfibrillated acrylic fiber, including, for example, fibrillated CFF fiber (available from Engineered Fiber Technology, Sheldon, Connecticut). In some embodiments, the microfibrillated fiber may be a microfibrillated cellulose fiber, including, for example, rayon such as Lyocell or Tencel. ENCEL In some embodiments, the microfibrillated fiber may be a microfibrillated p-aramid fiber, which includes, for example, T... WARON Pulp (Teijin Aramid, BV, Netherlands). In some embodiments, the microfibrillated fibers may be microfibrillated liquid crystal polymer (LCP) fibers, which include, for example, microfibrillated V... ECTRAN Fibers (available from Engineered Fibers Technologies, Sheldon, Connecticut). In some embodiments, the microfibrillated fiber may be microfibrillated poly(p-phenylenebenzobisoxazole) (PBO) fiber, which includes, for example, fibrillated Z… YLON Fiber (available from Engineered Fiber Technologies, Sheldon, Connecticut).

[0096] In some embodiments, each of the first and second filter media comprises at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 50 wt%, or at least 55 wt% of microfibrillated fibers. In some embodiments, the filter media comprises a maximum of 15 wt%, a maximum of 20 wt%, a maximum of 25 wt%, a maximum of 30 wt%, a maximum of 35 wt%, a maximum of 40 wt%, a maximum of 45 wt%, a maximum of 50 wt%, a maximum of 55 wt%, or a maximum of 60 wt% of microfibrillated fibers. In an exemplary embodiment, the filter media comprises 10 wt% to 60 wt% of microfibrillated fibers. In another exemplary embodiment, the filter media comprises 10 wt% to 40 wt% of microfibrillated fibers.

[0097] In some embodiments, the microfibrillated fibers can include microfibrillated cellulose. As used herein, microfibrillated cellulose (MFC) herein refers to a material as defined by G. Chinga-Carrasco in Nanoscale Research Letters [Nanoscale Research Letters], 2011; 6:417: “The MFC material can consist of (1) nanofibrils, (2) fibril-like fines, (3) fiber fragments, and (4) fibers. This implies that MFC is not necessarily synonymous with microfibrils, nanofibrils, or any other cellulose nanostructure. However, properly produced MFC material contains nanostmctures, i.e. nanofibrils, as the main component.” The diameters (or, for microfibrillated cellulose fibers, “cross dimensions”) of these components are reproduced in Table 1 of the same document and are as follows: (1) nanofibrils (<0.1 pm); (2) fibril-like fines (<1 pm); (3) fibers or fiber fragments (10 to 50 pm).

[0098] Further, the term “microfibrillated cellulose” as used herein does not include dry ground cellulose (also known as micronized cellulose or microfine cellulose), and does not include microcrystalline cellulose obtained by removing amorphous parts by acid hydrolysis, as described in U.S. Patent No. 5,554,287.

[0099] In some embodiments, a majority (i.e., more than half) of the microfibrillated fibers have a cross dimension (e.g., width in two dimensions) of at most 1 micron, at most 1.5 microns, at most 2 microns, at most 3 microns, or at most 4 microns. In some embodiments, a majority of the microfibrillated fibers have a cross dimension of at least 0.5 microns or at least 0.7 microns. In exemplary embodiments, a majority of the microfibrillated fibers have a cross dimension in the range of 0.5 microns to 4 microns. In another exemplary embodiment, a majority of the microfibrillated fibers have a cross dimension in the range of 0.5 microns to 1.5 microns. In further exemplary embodiments, a majority of the microfibrillated fibers have a cross dimension of at most 2 microns.

[0100] In some embodiments, the microfibrillated fibers are incorporated (i.e., distributed throughout) into a fibrous medium, thereby forming a filter media (also referred to herein as “filtration medium” or “filter medium”).

[0101] Third nonwoven filter medium

[0102] The third nonwoven filter medium includes “small efficiency fibers,” where “small efficiency fibers” as used herein are fibers having a fiber diameter of at least 0.1 microns and less than 1 micron.

[0103] In some embodiments, the low-efficiency fibers preferably comprise PET. In some embodiments, the low-efficiency fibers can consist essentially of PET. In some embodiments, the low-efficiency fibers can consist of PET.

[0104] Additionally or alternatively, the low-efficiency fibers can comprise nylon, acrylic, rayon, polypropylene, polyethylene, ethylene-vinyl alcohol (EVOH), polylactic acid (PLA), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), or other suitable melt-fusible polymer.

[0105] In some embodiments, the third nonwoven filter media can comprise fibers and components in addition to the low-efficiency fibers. These additional fibers and components can comprise bicomponent fibers, monocomponent heat fusible fibers, resins, and the like.

[0106] When the third nonwoven filter media can comprise fibers and components in addition to the low-efficiency fibers, the third nonwoven filter media preferably comprises at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, or at least 45 wt% of the low-efficiency fibers. In some embodiments, the third nonwoven filter media comprises a maximum of 15 wt%, a maximum of 20 wt%, a maximum of 25 wt%, a maximum of 30 wt%, a maximum of 35 wt%, a maximum of 40 wt%, a maximum of 45 wt%, or a maximum of 50 wt% of the low-efficiency fibers.

[0107] In some embodiments, the low-efficiency fibers have a fiber diameter of at least 0.1 microns, at least 0.2 microns, at least 0.3 microns, at least 0.4 microns, at least 0.5 microns, at least 0.6 microns, or at least 0.7 microns. In some embodiments, the low-efficiency fibers have a fiber diameter of a maximum of 0.7 microns, a maximum of 0.8 microns, a maximum of 0.9 microns, or less than 1 micron. For example, in an exemplary embodiment, the low-efficiency fibers have a fiber diameter of at least 0.4 microns and less than 1 micron. In another exemplary embodiment, the low-efficiency fibers have a fiber diameter in a range of 0.6 microns to 0.8 microns. In a further exemplary embodiment, the low-efficiency fibers have a fiber diameter of 0.7 microns (700 nm).

[0108] In some embodiments, the low-efficiency fibers have a length of at least 0.5 mm, at least 1 mm, or at least 1.5 mm. In some embodiments, the low-efficiency fibers have a length of a maximum of 10 mm, a maximum of 11 mm, a maximum of 12 mm, or a maximum of 15 mm. In an exemplary embodiment, the low-efficiency fibers have a length in a range of 1 mm to 15 mm. In a further exemplary embodiment, the low-efficiency fibers have a length in a range of 1 mm to 12 mm.

[0109] In one exemplary embodiment, the low-efficiency fibers are PET fibers having a fiber diameter of 0.7 microns.

[0110] In some embodiments, when the low-efficiency fibers comprise PET, the PET of the low-efficiency fibers has a melting point of at least 250°C, more preferably at least 275°C, even more preferably at least 290°C.

[0111] Support Layer

[0112] In some embodiments, the composite material comprises a support layer (also referred to as scrim). Any suitable support layer can be used.

[0113] The support layer can comprise or be made of any suitable porous material. In some embodiments, the support layer can preferably be polymeric.

[0114] Examples of suitable materials for the support layer include spunbond, wet-laid, carded, or meltblown nonwoven materials, or combinations thereof, including, for example, spunbond-meltblown-spunbond materials. The fibers can be in the form of a woven or nonwoven. Examples of synthetic nonwovens include polyester nonwovens, nylon nonwovens, polyolefin (e.g., polypropylene) nonwovens, polycarbonate nonwovens, or blended or multicomponent nonwovens thereof. Sheet-like support layers (e.g., cellulose webs, synthetic webs, and / or glass or combination webs) are typical examples of filter support layers. Other examples of suitable support layers include polyester or bicomponent polyester fibers or polypropylene / polyethylene terephthalate, or polyethylene / polyethylene terephthalate bicomponent fibers in a spunbond fabric.

[0115] In some embodiments, the support layer comprises a plurality of fibers or strands. The fibers or strands of the support layer are continuous or non-continuous. Continuous fibers (e.g., strands) are made by a “continuous” fiber forming process, such as a meltblown process, a meltspun process, an extrusion process, a woven yarn, a laid scrim, and / or a spunbond process, and typically have a longer length than non-continuous fibers, as described in more detail below. Non-continuous fibers are, for example, staple fibers, which are typically cut (e.g., from a filament) or formed into non-continuous discrete fibers to have a particular length or length range.

[0116] In certain embodiments, the plurality of fibers or strands of the support layer comprises synthetic fibers or strands (e.g., synthetic polymeric fibers or strands). The synthetic fibers or strands of the support layer can be continuous fibers. Non-limiting examples of suitable synthetic fibers / strands include polyesters, aramids, polyimides, polyolefins (e.g., polyethylenes such as high density polyethylene, low density polyethylene, and / or linear low density polyethylene), ethylene-vinyl acetate, polyacrylamides, polylactic acid, polypropylene, Kevlar, Nomex, halogenated polymers (e.g., polyethylene terephthalate), acrylics, polyphenylene oxide, polyphenylene sulfide, thermoplastic elastomers (e.g., thermoplastic polyurethane), polymethylpentene, and combinations thereof.

[0117] In some embodiments, the average pore size of the support layer is 100 microns or less, and typically at least 0.5 microns.

[0118] In some embodiments, the support scrim has a porosity of 20% or greater, and typically no more than 90%.

[0119] Exemplary support layers include those available from Midwest Filtering of Cincinnati, Ohio under the trade designations FINON C303NW and FINON C3019 NW, or those available under the trade designation CEREX 23200 (Cerex Advanced Fabrics, Cantonment, Florida). CEREX 23200 includes nylon 6,6 having a thickness of 8.4 mils (0.21 mm), a basis weight of 67.8 g / m2, a solidity of 28%, and a permeability / solidity of 615.1. Other exemplary scrim materials are described, for example, in U.S. Patent Publication 2009 / 0120868. 2 Basis weight, solidity, and permeability / solidity. Other exemplary scrim materials are described, for example, in U.S. Patent Publication 2009 / 0120868.

[0120] Methods of using the composite material

[0121] In another aspect, the present disclosure describes methods of using the composite material described herein.

[0122] In some embodiments, the method of using the composite material comprises filtering a liquid stream. For example, such a method can comprise passing a liquid stream comprising a contaminant through the composite material and removing the contaminant from the liquid stream.

[0123] The liquid stream can comprise, for example, fuel, hydraulic oil, process water, air, diesel engine fluid (DEF), diesel engine lubricating oil, blow-by gas, and the like, and combinations thereof.

[0124] In some embodiments, the method of using a composite material includes passing a liquid stream through a first nonwoven filtration medium, then through a second nonwoven filtration medium, then through a third nonwoven filtration medium.

[0125] Method of manufacturing a composite material

[0126] In another aspect, the disclosure describes a method of manufacturing a composite material.

[0127] In some embodiments, the first nonwoven filtration medium and the second nonwoven filtration medium can be independently manufactured. In some embodiments, the first nonwoven filtration medium and the third nonwoven filtration medium can be independently manufactured. In some embodiments, the second nonwoven filtration medium and the third nonwoven filtration medium can be independently manufactured. In some embodiments, the first nonwoven filtration medium, the second nonwoven filtration medium, and the third nonwoven filtration medium can be independently manufactured. When nonwoven filtration media are independently manufactured, they are not manufactured in the same process even if they are formed using the same method. For example, if each of the three filtration media is manufactured using a wet-laid process, if they are independently manufactured, they are formed in three separate wet-laid processes and then placed in contact with one another, rather than being formed in a single wet-laid process.

[0128] In some embodiments, at least one of the first nonwoven filtration medium, the second nonwoven filtration medium, and the third nonwoven filtration medium is formed using a wet-laid process. In some embodiments, the first nonwoven filtration medium, the second nonwoven filtration medium, and the third nonwoven filtration medium are formed using a wet-laid process.

[0129] In some embodiments, the method of manufacturing a composite material includes placing the first nonwoven filtration medium in contact with the second nonwoven filtration medium, or placing the second nonwoven filtration medium in contact with the third nonwoven filtration medium, or both.

[0130] When the composite material includes a support layer, the method can further include placing the third nonwoven filtration medium in contact with the support layer. In some embodiments, the method can include forming the third nonwoven filtration medium on the support layer.

[0131] In some embodiments, the method of manufacturing a composite material includes bonding the first nonwoven filtration medium to the second nonwoven filtration medium, or bonding the second nonwoven filtration medium to the third nonwoven filtration medium, or both. Any suitable means of bonding can be used, including, for example, lamination.

[0132] Exemplary composite material aspects

[0133] Aspect Al is a composite material comprising: a first nonwoven filtration medium comprising: 40 wt% to 90 wt% of a first bicomponent fiber having a fiber diameter in a range of 5 microns to 50 microns and a fiber length of 0.1 cm to 15 cm; 0 wt% to 25 wt% of a first high efficiency fiber having a fiber diameter in a range of 1 micron to 5 microns; and 10 wt% to 60 wt% of a first microfibillated fiber, wherein a majority of the microfibillated fiber has a transverse dimension of at most 4 microns; optionally, a second nonwoven filtration medium comprising: 40 wt% to 90 wt% of a second bicomponent fiber having a fiber diameter in a range of 5 to 50 microns and a fiber length of 0.1 cm to 15 cm; 0 wt% to 25 wt% of a second high efficiency fiber; and 10 wt% to 60 wt% of a second microfibillated fiber, wherein a majority of the microfibillated fiber has a transverse dimension of at most 4 microns; and a third nonwoven filtration medium comprising a low efficiency fiber having a fiber diameter of at least 0.1 micron and less than 1 micron; wherein the composite material is substantially free of glass fibers.

[0134] Aspect A2 is the composite material of Aspect Al, wherein the first bicomponent fiber includes a structural polymer portion and a thermoplastic binder polymer portion, wherein the structural polymer portion has a higher melting point than the melting point of the binder polymer portion.

[0135] Aspect A3 is the composite material of Aspect Al or A2, wherein the second bicomponent fiber includes a structural polymer portion and a thermoplastic binder polymer portion, wherein the structural polymer portion has a higher melting point than the melting point of the binder polymer portion.

[0136] Aspect A4 is the composite material of Aspect A2 or A3, wherein the structural polymer portion of the bicomponent fiber has a melting point of at least 240 °C and the binder polymer portion of the bicomponent fiber has a melting point of at most 115 °C.

[0137] Aspect A5 is the composite material of Aspect A2 or A3, wherein the structural polymer portion of the bicomponent fiber has a melting point of at least 240 °C and the binder polymer portion of the bicomponent fiber has a melting point in a range of 100 °C to 190 °C.

[0138] Aspect A6 is the composite material of Aspect A5, wherein the binder polymer portion of the bicomponent fiber has a melting point in a range of 140 °C to 160 °C.

[0139] Aspect A7 is the composite material of any one of Aspects Al to A6, wherein the first bicomponent fiber or the second bicomponent fiber includes at least two different bicomponent fibers.

[0140] Aspect A8 is the composite material of any of Aspects A1 to A7, wherein the first nonwoven filter media comprises 40 wt% to 60 wt% of the first bicomponent fibers.

[0141] Aspect A9 is the composite material of any of Aspects A1 to A8, wherein the second nonwoven filter media comprises 40 wt% to 60 wt% of the second bicomponent fibers.

[0142] Aspect A10 is the composite material of any of Aspects A1 to A9, wherein the first large efficiency fiber has a fiber diameter of 2.7 microns.

[0143] Aspect A11 is the composite material of any of Aspects A1 to A10, wherein the first large efficiency fiber comprises PET.

[0144] Aspect A12 is the composite material of any of Aspects A1 to A11, wherein the second fiber large efficiency fiber has a fiber diameter of 2.7 microns.

[0145] Aspect A13 is the composite material of any of Aspects A1 to A12, wherein the second large efficiency fiber comprises PET.

[0146] Aspect A14 is the composite material of any of Aspects A1 to A13, wherein the first nonwoven filter media comprises at least 10 wt% of the first large efficiency fiber.

[0147] Aspect A15 is the composite material of any of Aspects A1 to A14, wherein the second nonwoven filter media comprises at least 10 wt% of the second large efficiency fiber.

[0148] Aspect A16 is the composite material of any of Aspects A1 to A15, wherein a majority of the microfibillated fibers of the first nonwoven filter media have a transverse dimension of at most 2 microns.

[0149] Aspect A17 is the composite material of any of Aspects A1 to A16, wherein a majority of the microfibillated fibers of the second nonwoven filter media have a transverse dimension of at most 2 microns.

[0150] Aspect A18 is the composite material of any of Aspects A1 to A17, wherein a majority of the microfibillated fibers of the first nonwoven filter media have a transverse dimension in a range of 0.5 microns to 1.5 microns.

[0151] Aspect A19 is the composite material of any of Aspects A1 to A18, wherein a majority of the microfibillated fibers of the second nonwoven filter media have a transverse dimension in a range of 0.5 microns to 1.5 microns.

[0152] Aspect A20 is the composite material of any of Aspects A1 to A19, wherein the first nonwoven filter medium comprises 10 wt% to 40 wt% microfibillated fibers.

[0153] Aspect A21 is the composite material of any of Aspects A1 to A20, wherein the second nonwoven filter medium comprises 10 wt% to 40 wt% microfibillated fibers.

[0154] Aspect A22 is the composite material of any of Aspects A1 to A21, wherein the first nonwoven filter medium has a solidity in the range of 5% to 15%.

[0155] Aspect A23 is the composite material of any of Aspects A1 to A22, wherein the first nonwoven filter medium has a basis weight in the range of 24 g / m 2 to 100 g / m 2 .

[0156] Aspect A24 is the composite material of any of Aspects A1 to A23, wherein the first nonwoven filter medium has a pore size of 0.5 microns to 20 microns.

[0157] Aspect A25 is the composite material of any of Aspects A1 to A24, wherein the first nonwoven filter medium has a thickness in the range of 0.12 mm to 1 mm.

[0158] Aspect A26 is the composite material of any of Aspects A1 to A25, wherein the first nonwoven filter medium has a permeability in the range of 0.5 inches of water per 1 ft 3 / ft 2 / minute at 0.5 inches of water per 100 ft 3 / ft 2 / minute.

[0159] Aspect A27 is the composite material of any of Aspects A1 to A26, wherein the second nonwoven filter medium has a solidity in the range of 5% to 15%.

[0160] Aspect A28 is the composite material of any of Aspects A1 to A27, wherein the second nonwoven filter medium has a basis weight in the range of 24 g / m 2 to 100 g / m 2 .

[0161] Aspect A29 is the composite material of any of Aspects A1 to A28, wherein the second nonwoven filter medium has a pore size of 0.5 microns to 20 microns.

[0162] Aspect A30 is the composite material of any of Aspects A1 to A29, wherein the second nonwoven filter medium has a thickness ranging from 0.12 mm to 1 mm.

[0163] Aspect A31 is the composite material of any of Aspects A1 to A30, wherein the second nonwoven filter medium has a thickness ranging from 0.5 inches of water under 1 ft 3 / ft 2 / ft 3 / ft 2 / ft

[0164] Aspect A32 is the composite material of any of Aspects A1 to A31, wherein the low efficiency fiber has a fiber diameter of at least 0.4 microns and less than 1 micron.

[0165] Aspect A33 is the composite material of any of Aspects A1 to A32, wherein the low efficiency fiber has a fiber diameter ranging from 0.6 microns to 0.8 microns.

[0166] Aspect A34 is the composite material of any of Aspects A1 to A33, wherein the low efficiency fiber comprises a fiber having a fiber diameter of 0.7 microns.

[0167] Aspect A35 is the composite material of any of Aspects A1 to A34, wherein the low efficiency fiber PET comprises polyethylene terephthalate (PET).

[0168] Aspect A36 is the composite material of any of Aspects A1 to A35, wherein the composite material is substantially free of resin.

[0169] Aspect A37 is the composite material of any of Aspects A1 to A36, wherein the composite material is free of glass fibers.

[0170] Aspect A38 is the composite material of any of Aspects A1 to A37, wherein the first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium are discrete layers.

[0171] Aspect A39 is the composite material of any of Aspects A1 to A38, wherein the nonwoven filter medium is configured to pass a liquid through the first nonwoven filter medium, then through the second nonwoven filter medium, and then through the third nonwoven filter medium.

[0172] Aspect A40 is the composite material of any of Aspects A1 to A39, the nonwoven filter medium further comprising a support layer.

[0173] A41 is the composite of aspect A40, the support layer comprising a porous polymeric material.

[0174] Aspect A42 is the composite of any of aspects A40 or A41, wherein the nonwoven filtration medium is configured to pass liquid through the first nonwoven filtration medium, then through the second nonwoven filtration medium, then through the third nonwoven filtration medium, and then through the support layer.

[0175] Aspect A43 is the composite of any of aspects A40 to A42, wherein the third nonwoven filtration medium is in contact with the support layer.

[0176] Aspect A44 is the composite of any of aspects A1 to A43, wherein the first nonwoven filtration medium is in contact with the second nonwoven filtration medium, and the second nonwoven filtration medium is in contact with the third nonwoven filtration medium.

[0177] Aspect A45 is the composite of any of aspects A1 to A44, wherein the first high efficiency fiber comprises PET and the PET has a melting point of at least 250°C, at least 275°C, or at least 290°C.

[0178] Aspect A46 is the composite of any of aspects A1 to A45, wherein the second high efficiency fiber comprises PET and the PET has a melting point of at least 250°C, at least 275°C, or at least 290°C.

[0179] Aspect A47 is the composite of any of aspects A1 to A46, wherein the microfibillated fibers of the first nonwoven filtration medium comprise microfibillated cellulose fibers.

[0180] Aspect A48 is the composite of any of aspects A1 to A47, wherein the microfibillated fibers of the second nonwoven filtration medium comprise microfibillated cellulose fibers.

[0181] Exemplary methods using composite aspects

[0182] Aspect B1 is a method of filtering a liquid stream, the method comprising passing a liquid stream comprising a contaminant through a composite of any of the “Exemplary Composite Aspects” (aspects A1 to A48) and removing the contaminant from the liquid stream.

[0183] Aspect B2 is the method of aspect B1, wherein the liquid stream comprises fuel, hydraulic oil, process water, air, diesel engine fluid (DEF), diesel engine lubricating oil, or blowby gas, or combinations thereof.

[0184] Aspect B3 is the method of Aspect B1 or B2, wherein the liquid stream is passed through the first nonwoven filtration medium, then through the second nonwoven filtration medium, then through the third nonwoven filtration medium.

[0185] Exemplary methods of making composite materials

[0186] Aspect C1 is a method of making the composite material of any of the “Exemplary Composite Material Aspects” (Aspects Al to A48), the method comprising independently making the first nonwoven filtration medium, the second nonwoven filtration medium, and the third nonwoven filtration medium.

[0187] Aspect C2 is the method of Aspect C1, wherein the first nonwoven filtration medium, the second nonwoven filtration medium, and the third nonwoven filtration medium are formed using a wet-laid process.

[0188] Aspect C3 is the method of Aspect C1 or C2, the method further comprising placing the first nonwoven filtration medium in contact with the second nonwoven filtration medium, or placing the second nonwoven filtration medium in contact with the third nonwoven filtration medium.

[0189] Aspect C4 is the method of Aspect C3, the method further comprising bonding the first nonwoven filtration medium with the second nonwoven filtration medium, or bonding the second nonwoven filtration medium with the third nonwoven filtration medium, or both.

[0190] Aspect C5 is the method of Aspect C4, wherein bonding comprises lamination.

[0191] Aspect C6 is the method of any of Aspects C1 to C5, the method further comprising placing the third nonwoven filtration medium in contact with a support layer.

[0192] The present application is illustrated by the following examples. It is to be understood that the particular examples, materials, amounts, and procedures are to be interpreted broadly and are only for purposes of illustration and not limitation.

[0193] Examples

[0194] All reagents, starting materials, and solvents used in the following examples were purchased from commercial suppliers (e.g., Sigma-Aldrich, St. Louis, MO) and used without further purification unless otherwise noted.

[0195] Medium characterization

[0196] Liquid filtration performance testing

[0197] Differential pressure and 4 pm beta (beta 4μm). The test medium was as described in ISO 16889:2008 (Hydraulic fluid power— Filters— Multi-pass method for evaluating filtration performance of a filter element) except that ISO fine test dust was used instead of ISO medium test dust to load the hydraulic fluid. The medium area was 0.0507 m 2 ; the test flow rate was 2 L / min, and the test was run to a terminal element differential pressure of 200 kPa.

[0198] Caliper

[0199] The caliper (c) of a nonwoven layer (including, for example, a non-fine fiber layer or a composite including a fine fiber layer and a non-fine fiber layer) was calculated using the following equation:

[0200] c = BW / pZ

[0201] where BW is the basis weight, p is the density of the fiber, and Z is the thickness of the medium.

[0202] Thickness was measured according to TAPPI T411 om-15, entitled "Thickness (caliper) of paper, paperboard, and combined board" using a foot pressure of 1.5 psi. Basis weight was measured using TAPPI T410.

[0203] Example 1

[0204] This example describes the improved efficiency and life obtained by using a composite including a fine fiber layer.

[0205] A flat sheet was prepared including a scrim (1 oz / yd 2 Reemay, sold under the trade designation Reemay®) and a 10XP (Donaldson Company, Inc., Minneapolis, MN Figure 2A , left panel), or using the same scrim (having a layer of electrospun 1 pm diameter fine fibers thereon) and a 10XP Figure 2A , right panel).

[0206] As shown in FIG. 1 Figure 1A , the addition of a fine fiber layer improves the load capacity (i.e., life) of the flat sheet compared to a flat sheet without a fine fiber layer. As shown in FIG. 2Figure 1B As shown, the addition of the fine fiber layer improves the efficiency of the flat sheet compared to a flat sheet without the fine fiber layer.

[0207] These results are unexpected because it has been previously reported that creating interfaces between media layers is undesirable and that, instead, a graded structure should be pursued. (See, for example, U.S. Pub. No. 2014 / 0360145.)

[0208] Without wishing to be bound by theory, it is believed that creating interfaces between media layers can allow for higher efficiency because the inhomogeneity of each layer is not uniform across the depth of the media.

[0209] Example 2

[0210] In a flat sheet comprising a scrim, a 700 nm diameter PET fiber layer, and a handsheet prepared as described in Example 1 comprising 40-60% 14 pm diameter bicomponent fibers, 0-25% 2.5 pm diameter PET fibers, and 10-40% 1 pm diameter fibrillated rayon fibers Figure 2B ) it is expected to see the same increase in loading capacity and efficiency reported in Example 1.

[0211] Without wishing to be bound by theory, it is believed that the 700 nm diameter PET fiber layer will act as an efficiency layer and the handsheet will act as a loading layer. The variable efficiency (that would otherwise be observed if the handsheet was used alone) is expected to be eliminated by the combination with the 700 nm diameter PET fibers (acting as an efficiency layer).

[0212] Without wishing to be bound by theory, it is believed that creating interfaces between media layers can allow for higher efficiency because the inhomogeneity of each layer is not uniform across the depth of the media.

[0213] The entire disclosure of all patents, patent applications, and publications cited herein and the electronically available material on the internet are incorporated by reference. In the event that any inconsistency exists between the disclosure of the present application and the disclosure(s) by virtue of their incorporation into the present application by reference, the disclosure of the present application shall govern. The foregoing detailed description and examples have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. The application is not limited to the exact details shown and described, for variations obvious to one skilled in the art will be included within the application defined by the claims.

Claims

1. A composite material, the composite material comprising: The first nonwoven filter media comprises: The first bicomponent fiber comprises 40 wt% to 90 wt% of fiber diameter in the range of 5 micrometers to 50 micrometers and fiber length in the range of 0.1 cm to 15 cm. The first high-efficiency fiber has a fiber diameter in the range of 1 micrometer to 5 micrometers, ranging from 0 wt% to 25 wt%. as well as 10 wt% to 60 wt% of the first microfibrillated fiber, wherein most of the microfibrillated fiber has a transverse dimension of up to 4 micrometers; Optionally, the second nonwoven filter media comprises: 40 wt% to 90 wt% of a second bicomponent fiber, the second bicomponent fiber having a fiber diameter in the range of 5 micrometers to 50 micrometers and a fiber length of 0.1 cm to 15 cm; The second most efficient fiber is 0 wt% to 25 wt%, and the second most efficient fiber has a fiber diameter in the range of 1 micrometer to 5 micrometers; as well as 10 wt% to 60 wt% of a second microfibril, wherein most of the microfibril has a transverse dimension of up to 4 micrometers; as well as The third nonwoven filter medium comprises small-efficiency fibers with a fiber diameter of at least 0.1 micrometers and less than 1 micrometer; The composite material contains less than 1 wt% glass fiber.

2. The composite material as described in claim 1, wherein, The structural polymer portion of the bicomponent fiber has a melting point of at least 240°C, and the adhesive polymer portion of the bicomponent fiber has a melting point in the range of 100°C to 190°C.

3. The composite material as described in claim 1 or 2, wherein, The first high-efficiency fiber comprises polyethylene terephthalate (PET), or the second high-efficiency fiber comprises PET, or the first high-efficiency fiber comprises PET and the second high-efficiency fiber comprises PET.

4. The composite material according to any one of claims 1-2, wherein, The low-efficiency fiber has a fiber diameter in the range of 0.6 micrometers to 0.8 micrometers.

5. The composite material according to any one of claims 1-2, wherein, The low-efficiency fiber includes polyethylene terephthalate (PET).

6. The composite material according to any one of claims 1-2, wherein, The composite material is essentially resin-free.

7. The composite material according to any one of claims 1-2, wherein, The composite material does not contain glass fiber.

8. The composite material according to any one of claims 1-2, wherein, The first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium are discrete layers.

9. The composite material according to any one of claims 1-2, wherein, The nonwoven filter medium is configured to allow liquid to pass through the first nonwoven filter medium, then through the second nonwoven filter medium, and then through the third nonwoven filter medium.

10. The composite material according to any one of claims 1-2, wherein the nonwoven filter medium further comprises a support layer.

11. The composite material as claimed in claim 10, wherein, The third nonwoven filter medium is in contact with the support layer.

12. The composite material according to any one of claims 1-2, wherein, The microfibrillated fibers include microfibrillated cellulose fibers.

13. A method for filtering a liquid stream, the method comprising: The liquid containing contaminants is passed through the composite material described in any one of the preceding claims, and Remove the contaminants from the liquid stream.

14. The method of claim 13, wherein, The liquid stream contains air.

15. A method for manufacturing the composite material as claimed in claim 1, the method comprising: The first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium are manufactured independently.

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