Filtering composite material

Abstract

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

Description

Cross-references to related applications

[0001] 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

[0002] 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

[0003] 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.

[0004] 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.

[0005] 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.

[0006] In some embodiments, the first high-efficiency fiber includes polyethylene terephthalate (PET), the second high-efficiency fiber includes PET, or both the first and second high-efficiency fibers include PET.

[0007] In some embodiments, the low-efficiency fibers have a fiber diameter in the range of 0.6 micrometers to 0.8 micrometers.

[0008] In some embodiments, the low-efficiency fiber includes polyethylene terephthalate (PET).

[0009] In some embodiments, the composite material is substantially resin-free.

[0010] In some embodiments, the composite material does not contain glass fibers.

[0011] In some embodiments, the first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium are discrete layers.

[0012] In some embodiments, the nonwoven filter media are configured to allow liquid to pass through a first nonwoven filter media, then through a second nonwoven filter media, and then through a third nonwoven filter media.

[0013] In some embodiments, the nonwoven filter media further includes a support layer. A third nonwoven filter media may be in contact with the support layer.

[0014] In some embodiments, microfibrillated fibers include microfibrillated cellulose fibers.

[0015] On the other hand, this disclosure describes a method for filtering a liquid stream, the method comprising passing a liquid stream containing a contaminant through a composite material as described herein, and removing the contaminant from the liquid stream. The liquid stream may contain air.

[0016] On the other hand, this disclosure describes a method for 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.

[0017] As used in this article, micron is equivalent to micrometer (µm).

[0018] As used herein, a "fiber" has an aspect ratio (i.e., the ratio of length to transverse dimension) greater than 3:1, and preferably greater than 5:1. For example, glass fibers typically have an aspect ratio greater than 100:1. In this context, "transverse dimension" refers to 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 maximum 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.

[0019] As used herein, "β ratio" or "β" refers to the ratio of upstream particles to downstream particles under steady-flow conditions (ISO 16889:2008), as illustrated in the examples. A higher filter efficiency results in a higher β ratio. The β ratio is defined as follows: .

[0020] in N d,U It is the upstream particle count per unit fluid volume for particles with a diameter of d or larger, and N d,D This is the downstream particle count per unit fluid volume for particles with a diameter of d or larger. If present, append a subscript to β (e.g., d () Indicates the particle size of the ratio being reported.

[0021] As used herein, the term "substantially free" indicates that the filter media does not contain any amount of the listed components (e.g., glass fibers or resins) that contribute to the activity or function of the filter media in any substantial way. This term is intended to include trace amounts of components that do not contribute substantially to the filtration properties of the filter media. For example, a substantially glass-free filter media may include less than 1 wt% glass fibers. For example, a substantially resin-free filter media may include less than 5 wt% resin.

[0022] As used herein, the term "free of" indicates that the filter media does not contain a certain amount of the listed components (e.g., glass fiber or resin). For example, "glass-free" filter media does not contain any glass, and "resin-free" media does not contain any resin.

[0023] Unless otherwise stated, any reference to standard methods (e.g., ASTM, TAPPI, etc.) refers to the most recent available version of that method at the time of submission of this disclosure.

[0024] The terms "preferred" and "ideally" refer to embodiments of the invention that may provide certain benefits in certain circumstances. However, other embodiments may also be preferred in the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.

[0025] Where the term "comprising" and its variations appear in the specification and claims, these terms are not restrictive. Such terms should be understood to imply inclusion of the stated steps or elements or a group of steps or elements, but not to exclude any other steps or elements or any other group of steps or elements.

[0026] "Comprising of..." means including and limited to anything contained in the phrase "comprising of...". Therefore, the phrase "comprising of..." indicates that the listed element is necessary or mandatory, and other elements may not be present. "Substantially comprising..." means including any element listed in the phrase, and limited to other elements that do not impede or contribute to the function or role specified in this disclosure for the listed element. Therefore, the phrase "substantially comprising..." indicates that the listed element is necessary or mandatory, but other elements are optional and may or may not be present, depending on whether they substantially affect the function or role of the listed element.

[0027] Unless otherwise stated, “a type”, “the” and “at least one type” are used interchangeably and mean one type or more than one type.

[0028] As used herein, the term “or” is generally used in its usual sense, which includes “and / or”, unless the context clearly indicates otherwise.

[0029] The term “and / or” means one or all of the listed elements or any combination of two or more of the listed elements.

[0030] Furthermore, in this document, the numerical range is described by endpoints to include all numbers falling within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0031] In this article, “maximum is” a certain number (e.g., maximum is 50) includes that number (e.g., 50).

[0032] The term "in the range" (and similar statements) includes the endpoints of the stated range.

[0033] For any method disclosed herein that includes discrete steps, these steps can be performed in any feasible order. Furthermore, any combination of two or more steps can be performed simultaneously, where appropriate.

[0034] All headings are intended to facilitate the reader and should not be used to limit the meaning of the text that follows the heading, unless otherwise specified.

[0035] Throughout this specification, the terms "an embodiment," "an embodiment," "some embodiments," or "a number of embodiments," etc., refer to specific features, configurations, compositions, or characteristics described in connection with that embodiment, which are included in at least one embodiment of this disclosure. Therefore, the appearance of such phrases throughout this specification does not necessarily refer to the same embodiment of this disclosure. Furthermore, in one or more embodiments, specific features, configurations, compositions, or characteristics may be combined in any suitable manner.

[0036] Unless otherwise stated, all figures indicating the quantity of components, molecular weight, etc., used in the specification and claims should be understood to be modified by the term "about" in all cases. When used herein in conjunction with the quantity measured, the term "about" refers to a variation in the measured quantity as would be expected by a person skilled in the art to perform the measurement and to operate with a level of care commensurate with the purpose of the measurement and the accuracy of the measuring equipment used. Therefore, unless otherwise indicated to the contrary, the numerical parameters set forth in this specification and claims are approximations, which may vary depending on the desired characteristics sought to be obtained by the invention. At least, and not in an attempt to limit the scope of the claims, each numerical parameter should be interpreted at least according to the number of significant digits reported and by applying general rounding methods.

[0037] While the numerical ranges and parameters illustrating the broad scope of the invention are approximate, the values ​​described in specific examples are reported as precisely as possible. However, all values ​​inherently contain ranges that are necessarily generated by the standard deviations found in their respective test measurements.

[0038] The above summary of the invention is not intended to describe every disclosed embodiment or implementation of the invention. The following description provides more specific examples of illustrative embodiments. Throughout this application, guidance is provided by a list of examples that can be used in various combinations. In each case, the enumerated list is intended only as a representative group and should not be construed as an exclusive list. Attached Figure Description

[0039] Figure 1A The load capacity of the composite material prepared as described in Example 1 is shown. Figure 1B The efficiency of a composite material including a fine fiber layer prepared as described in Example 1 is shown.

[0040] Figure 2A A schematic diagram of an exemplary composite material is shown, which in some embodiments can be prepared as described in Example 1. Figure 2B A schematic diagram of an exemplary composite material is shown. Figure 2C A schematic diagram of an exemplary composite material is shown, which in some embodiments can be prepared as described in Example 2. Detailed Implementation

[0041] 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. Composite materials

[0042] In one aspect, this disclosure describes a composite material comprising a plurality of nonwoven filter media. In some embodiments, each nonwoven filter media is preferably substantially glass-free or glass-free.

[0043] The composite material comprises a first nonwoven filter medium, an optional second nonwoven filter medium, and a third nonwoven filter medium. The first nonwoven filter medium comprises a first bicomponent fiber; a first high-efficiency fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers; and a first microfibrillated fiber. The second nonwoven filter medium, if present, comprises a second bicomponent fiber; a second high-efficiency fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers; and a second microfibrillated fiber. The third nonwoven filter medium comprises small-efficiency fibers having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer. As used herein, a "high-efficiency fiber" is a fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers. As used herein, a "small-efficiency fiber" is a fiber having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer.

[0044] In some embodiments, the low-efficiency fiber preferably comprises polyethylene terephthalate (PET). In some embodiments, the first high-efficiency fiber preferably comprises PET. In some embodiments, the second high-efficiency fiber preferably comprises PET.

[0045] In some embodiments, fibers or composite material layers of one or more composite materials may be selected or treated to alter the electrostatic charge of the medium. Charge typically includes layers of positive or negative charges trapped at or near the polymer surface, or a charge cloud stored in the polymer bulk. Charge may also include polarization charges that are frozen when the dipoles of the molecules align. Methods for subjecting materials to charge 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.

[0046] In some embodiments, the composite material further includes a support layer.

[0047] In some embodiments, the first nonwoven filter medium, an 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 and second nonwoven filter media or between the second and third nonwoven filter media. If the second nonwoven filter medium is absent, there is no gradient between the first and third nonwoven filter media.

[0048] 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 material further includes a support layer, the third nonwoven filter medium may be in contact with the support layer.

[0049] In some embodiments, the composite material is configured to allow liquid to pass through a first nonwoven filter medium, then through a second nonwoven filter medium, and then through a third nonwoven filter medium.

[0050] In some embodiments, when the composite material includes a support layer, the composite material is configured to allow liquid to pass through a first nonwoven filter medium, then through a second nonwoven filter medium, then through a third nonwoven filter medium, and then through the support layer.

[0051] In some embodiments, the first nonwoven filter medium is in contact with a third nonwoven filter medium. When the composite material further includes a support layer, the third nonwoven filter medium may be in contact with the support layer.

[0052] In some embodiments, the composite material is configured to allow liquid to pass through a first nonwoven filter medium and then through a third nonwoven filter medium. When the composite material further includes a support layer, the composite material is configured to allow liquid to pass through the first nonwoven filter medium, then through the third nonwoven filter medium, and then through the support layer.

[0053] In some embodiments, the composite material is substantially resin-free. In some embodiments, the composite material does not contain resin.

[0054] The composite material is substantially free of glass (including, for example, glass fibers). In some embodiments, the composite material does not contain glass.

[0055] In an exemplary embodiment, the composite material 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 a first 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 first high-efficiency fiber; and 10 wt% to 60 wt% of a first microfibrilated fiber, wherein a majority of the microfibrilated fiber has a transverse dimension of at most 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; and 10 wt% to 60 wt% of a second microfibrilated fiber, wherein a majority of the microfibrilated fiber has a transverse dimension of at most 4 micrometers. The third nonwoven filter media contains low-efficiency fibers.

[0056] Figure 2C An exemplary embodiment is shown in the figure.

[0057] As described in Example 1, adding a 1µm diameter electrospun fiber layer to the filter media composite improved the composite's efficiency compared to the composite without the fiber layer. Further descriptions in Example 2 and as... Figure 2C As shown, the fine fiber layer can be replaced by a layer comprising low-efficiency fine fibers, and the resulting composite material is expected to have similar efficiency to the composite material comprising the fine fiber layer.

[0058] The result of Example 1 was unexpected, as it had been previously reported that creating interfaces between dielectric layers is undesirable, and instead, gradient structures should be pursued. See, for example (US Publication No. 2014 / 0360145.) To avoid being bound by theory, it is believed that creating an interface between media layers (including, for example, nonwoven filter media layers, which consist of layers containing low-efficiency fine fibers and filter media layers acting as load layers) can allow for higher efficiency than using gradient structures, because the inhomogeneity of each layer is not consistent throughout the depth of the media. First and second nonwoven filter media

[0059] The first nonwoven filter medium and the optional second nonwoven filter medium (if present) each comprise bicomponent fibers, high-efficiency fibers having a fiber diameter in the range of 1 micrometer to 5 micrometers, and microfibrillated fibers.

[0060] In some embodiments, either or both of the first and second nonwoven filter media serve as a load layer, i.e., a filter media distributed throughout the depth of the medium at locations where contaminants are collected. Figure 2C An exemplary embodiment in which both the first and second nonwoven filter media act as load layers is described. Figure 2B An exemplary embodiment is shown in which a second nonwoven filter media is not included.

[0061] In some embodiments, either or both of the first and second nonwoven filter media have 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 have a solidity of a maximum of 5%, a maximum of 6%, a maximum of 7%, a maximum of 8%, a maximum of 9%, a maximum of 10%, a maximum of 11%, a maximum of 12%, a maximum of 13%, a maximum of 14%, a maximum of 15%, a maximum of 16%, a maximum of 17%, a maximum of 18%, a maximum of 19%, or a maximum of 20%. In an exemplary embodiment, the first nonwoven filter media has a solidity in the range of 5% to 15%. In an exemplary embodiment, 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.

[0062] In some embodiments, either or both of the first and second nonwoven filter media have a concentration of at least 20 g / m³. 2 At least 24 g / m 2 At least 25 g / m 2 At least 30 g / m 2 At least 35 g / m 2 At least 40 g / m 2 At least 50 g / m 2 At least 60 g / m 2 or at least 70 g / m 2 The basis weight. In some embodiments, the nonwoven filter media has a maximum weight of 25 g / m³. 2 The maximum is 30 g / m 2 The maximum is 35 g / m 2 The maximum is 40 g / m 2 The maximum is 50 g / m 2 The maximum is 60 g / m 2 The maximum is 70 g / m 2 The maximum is 75 g / m 2 The maximum is 80 g / m 2 The maximum is 85 g / m 2The maximum is 90 g / m 2 The maximum is 95 g / m 2 The maximum is 100 g / m 2 or a maximum of 105 g / m 2 The basis weight. In an exemplary embodiment, the first nonwoven filter medium has a basis weight of 24 g / m³. 2 Up to 100 g / m 2 The basis weight is within the range. In an exemplary embodiment, the second nonwoven filter medium has a basis weight of 24 g / m³. 2 Up to 100g / m 2 Basis weight within the range. In some embodiments, the basis weight is preferably measured using ASTM D646-13.

[0063] In some embodiments, either or both of the first and second nonwoven filter media have a pore size of at least 0.5 micrometers, at least 1 micrometer, at least 1.5 micrometers, at least 2 micrometers, at least 3 micrometers, at least 5 micrometers, or at least 10 micrometers. In some embodiments, the nonwoven filter media have a pore size of a maximum of 5 micrometers, a maximum of 10 micrometers, a maximum of 15 micrometers, or a maximum of 20 micrometers. In an exemplary embodiment, the first nonwoven filter media has a pore size in the range of 0.5 micrometers to 20 micrometers. In an exemplary embodiment, the second nonwoven filter media has a pore size in the range of 0.5 micrometers to 20 micrometers. In another exemplary embodiment, the first nonwoven filter media has a pore size in the range of 2 micrometers to 15 micrometers. In another exemplary embodiment, the second nonwoven filter media has a pore size in the range of 2 micrometers to 15 micrometers. As used herein, pore size refers to the average flow pore size, calculated as described in ASTM F316-03.

[0064] In some embodiments, either or both of the first and second nonwoven filter media have 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 media have 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 an exemplary embodiment, the first nonwoven filter media has a thickness in the range of 0.12 mm to 1 mm. In an exemplary embodiment, the second nonwoven filter media has a thickness in the range of 0.12 mm to 1 mm. In some embodiments, the thickness of the filter media is preferably measured using a foot pressure of 1.5 psi according to the TAPPI T411 om-15 test method.

[0065] In some embodiments, either or both of the first and second nonwoven filter media have a minimum depth of 1 ft at 0.5 inches of water. 3 / ft2 / min, at least 5 ft underwater at 0.5 inches. 3 / ft 2 / min, or at least 10 ft underwater at 0.5 inches. 3 / ft 2 / min of permeability. In some embodiments, the nonwoven filter media has a maximum permeability of 10 ft at 0.5 inches of water. 3 / ft 2 / min, maximum 20 ft at 0.5 inches underwater. 3 / ft 2 / min, maximum 50 ft at 0.5 inches underwater. 3 / ft 2 / min, maximum 75 ft at 0.5 inches underwater. 3 / ft 2 / min, or up to 100 ft at 0.5 inches of water. 3 / ft 2 / min of permeability. In an exemplary embodiment, the first nonwoven filter media has a permeability of 1 ft at 0.5 inches of water. 3 / ft 2 / min to 100 ft at 0.5 inches underwater 3 / ft 2 The permeability is within the range of / min. In an exemplary embodiment, the second nonwoven filter media has a permeability of 1 ft in 0.5 inches of water. 3 / ft 2 / min to 100 ft at 0.5 inches underwater 3 / ft 2 The permeability is within the range of / min. In another exemplary embodiment, the first nonwoven filter medium has a permeability of 10 ft at a depth of 0.5 inches underwater. 3 / ft 2 / min to 75 ft underwater at 0.5 inches 3 / ft 2 The permeability is within the range of / min. In another exemplary embodiment, the second nonwoven filter media has a permeability of 10 ft at a depth of 0.5 inches underwater. 3 / ft 2 / min to 75 ft underwater at 0.5 inches 3 / ft 2 Permeability within the range of / min. In some embodiments, permeability is preferably measured according to ASTM D737-18.

[0066] In some embodiments, either or both of the first and second nonwoven filter media are substantially resin-free.

[0067] In some embodiments, either or both of the first and second nonwoven filter media are substantially free of glass fibers. bicomponent fibers

[0068] The first and second filter media each comprise bicomponent fibers. Any suitable bicomponent fiber can be used for each media, and the bicomponent fiber can be selected based on the intended use of the media.

[0069] In some embodiments, each of the first and second filter media comprises 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% of bicomponent fibers. In some embodiments, each of the first and second filter media comprises 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%, a maximum of 60 wt%, a maximum of 65 wt%, a maximum of 70 wt%, a maximum of 75 wt%, a maximum of 80 wt%, a maximum of 85 wt%, or a maximum of 90 wt% of bicomponent fibers. In an exemplary embodiment, the first filter media comprises 40 wt% to 90 wt% of bicomponent fibers. In an exemplary embodiment, the second filter media comprises 40 wt% to 90 wt% of bicomponent fibers. In another exemplary embodiment, the first filter medium comprises 40 wt% to 75 wt% of bicomponent fibers. In an exemplary embodiment, the second filter medium comprises 40 wt% to 75 wt% of bicomponent fibers.

[0070] In some embodiments, the bicomponent fiber has a fiber diameter of at least 1 micrometer, at least 5 micrometers, at least 10 micrometers, at least 15 micrometers, or at least 20 micrometers. In some embodiments, the bicomponent fiber has a fiber diameter of a maximum of 5 micrometers, a maximum of 10 micrometers, a maximum of 15 micrometers, a maximum of 20 micrometers, a maximum of 25 micrometers, a maximum of 30 micrometers, a maximum of 35 micrometers, a maximum of 40 micrometers, a maximum of 45 micrometers, or a maximum of 50 micrometers. In an exemplary embodiment, the bicomponent fiber has a fiber diameter in the range of 5 micrometers to 50 micrometers. In another exemplary embodiment, the bicomponent fiber has a fiber diameter in the range of 5 micrometers to 25 micrometers. In another exemplary embodiment, the bicomponent fiber has a fiber diameter of 14 micrometers.

[0071] 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 a maximum of 0.5 cm, a maximum of 1 cm, a maximum of 5 cm, a maximum of 10 cm, or a maximum of 15 cm. In an exemplary embodiment, the bicomponent fibers have a fiber length in the range of 0.1 cm to 15 cm. In another exemplary embodiment, the bicomponent fibers have a fiber length of 6 mm.

[0072] 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 binder polymer portion.

[0073] The structural polymer portion and the adhesive polymer portion can be made of any suitable material. For example, the structural polymer portion may include PET, and the adhesive polymer portion may include copolymerized PET (coPET). In other examples, the structural polymer portion may include PET, and the adhesive polymer portion may include polyethylene (PE), PET, nylon, polypropylene (PP), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyphenylene sulfide (PPS), meta-aramid, or para-aramid. In other examples, the adhesive polymer portion may 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.

[0074] In some embodiments, the structural polymer portion is the core of the bicomponent fiber, and the thermoplastic adhesive polymer portion is the sheath of the bicomponent fiber.

[0075] 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 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 adhesive polymer portion has a melting point of at most 115°C) is 271P, a 14 µm diameter fiber available from Advansa (Hamm, Germany).

[0076] 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. In one exemplary embodiment, 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 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 adhesive polymer portion of the bicomponent fiber has a melting point in the range of 140°C to 160°C.

[0077] Exemplary bicomponent fibers (wherein 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) and TJ04BN (with a binder polymer portion melting point of 150°C), both available from Teijin Fibers Limited, Osaka, Japan; 271P (with a binder polymer portion melting point of 110°C), available from Advansa GmbH, 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.

[0078] In some embodiments, the first bicomponent fiber and the second bicomponent fiber may comprise two different bicomponent fibers or two different combinations of bicomponent fibers. In an exemplary embodiment, the bicomponent fiber may comprise a first bicomponent fiber (where the structural portion has a melting point of at least 240°C and the adhesive 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 adhesive polymer portion has a melting point in the range of 100°C to 190°C). For example, the bicomponent fiber may comprise Advansa 271P and TJ04BN. High-efficiency fibers

[0079] The first and second filter media may each include “high-efficiency fibers,” wherein “high-efficiency fibers,” as used herein, are fibers having a fiber diameter in the range of 1 micrometer to 5 micrometers. In some embodiments, one or both of the first and second filter media may not include high-efficiency fibers.

[0080] In some embodiments, the high-efficiency fiber is preferably PET fiber. In some embodiments, the high-efficiency fiber may be substantially composed of PET. In some embodiments, the high-efficiency fiber may be composed of PET.

[0081] Alternatively or alternatively, low-efficiency fibers may include nylon, acrylic, rayon, polypropylene, polyethylene, ethylene-vinyl alcohol (EVOH), polylactic acid (PLA), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), or other suitable meltable polymers.

[0082] In some embodiments, each of the first and second filter media comprises 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% high-efficiency fibers. In some embodiments, each of the first and second filter media comprises a maximum of 15 wt%, a maximum of 20 wt%, or a maximum of 25 wt% high-efficiency fibers. In an exemplary embodiment, the first filter media comprises 0 wt% to 25 wt% high-efficiency fibers. In an exemplary embodiment, the second filter media comprises 0 wt% to 25 wt% high-efficiency fibers. In another exemplary embodiment, the first filter media comprises 10 wt% to 25 wt% high-efficiency fibers. In another exemplary embodiment, the second filter media comprises 10 wt% to 25 wt% high-efficiency fibers.

[0083] In some embodiments, the high-efficiency fiber has a fiber diameter of at least 1 micrometer, at least 1.5 micrometers, at least 2 micrometers, at least 3 micrometers, or at least 4 micrometers. In some embodiments, the high-efficiency fiber has a fiber diameter of a maximum of 1.5 micrometers, a maximum of 2 micrometers, a maximum of 3 micrometers, a maximum of 4 micrometers, or a maximum of 5 micrometers. For example, in an exemplary embodiment, the high-efficiency fiber has a fiber diameter in the range of 2 micrometers to 4 micrometers. In another exemplary embodiment, the high-efficiency fiber has a fiber diameter of 2.7 micrometers. In yet another exemplary embodiment, the high-efficiency fiber has a fiber diameter of 2.5 micrometers.

[0084] In this example, the high-efficiency fiber comprises PET and has a fiber diameter of 2.7 micrometers.

[0085] In some embodiments, the high-efficiency fiber has a length of at least 0.5 mm, at least 1 mm, or at least 1.5 mm. In some embodiments, the high-efficiency fiber has 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 high-efficiency fiber has a length in the range of 1 mm to 15 mm. In another exemplary embodiment, the high-efficiency fiber has a length in the range of 1 mm to 12 mm.

[0086] In some embodiments, when the high-efficiency fiber comprises PET, the PET has a melting point of at least 250°C, more preferably at least 275°C, and even more preferably at least 290°C. Microfiber

[0087] The first and optional second filter media each comprise microfibrillated fibers. As used herein, microfibrillated fibers are fibers that have been processed to produce fibers with a higher surface area and branched structure than unprocessed fibers.

[0088] 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. In some embodiments, the microfibrillated fiber may be a microfibrillated p-aramid fiber, including, for example, Twaron Pulp (Teijin Aramid, BV, Netherlands). In some embodiments, the microfibrillated fiber may be a microfibrillated liquid crystal polymer (LCP) fiber, including, for example, microfibrillated Vectran fiber (available from Engineered Fiber Technology, Sheldon, Connecticut). In some embodiments, the microfibrillated fiber may be a microfibrillated poly(p-phenylenebenzobisoxazole) (PBO) fiber, including, for example, fibrillated Zylon fiber (available from Engineered Fiber Technology, Sheldon, Connecticut).

[0089] 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.

[0090] In some embodiments, microfibrillated fibers may include microfibrillated cellulose. As used herein, microfibrillated cellulose (MFC) refers to cellulose produced by G. Chinga-Carrasco. Nanoscale Research Letters [ Nanotechnology Research Express The material defined in [ ], 2011; 6:417: "MFC materials may consist of: (1) nanofibers, (2) filamentous particles, (3) fiber fragments and (4) fibers. This implies that MFC is not necessarily synonymous with microfibers, nanofibers or any other cellulose nanostructures. However, properly manufactured MFC materials contain nanostructures, i.e., nanofibers, as the main component." The diameters of these components (or "lateral dimensions" for microfibrillated cellulose fibers) are reproduced in Table 1 of the same document and are as follows: (1) nanofibers (< 0.1 µm); (2) filamentous particles (< 1 µm); (3) fibers or fiber fragments (10 to 50 µm).

[0091] Furthermore, as used herein, the term “microfibrillated cellulose” does not include dry-milled cellulose (also known as micronized cellulose or fine cellulose) and does not include microcrystalline cellulose obtained by removing the amorphous portion through acid hydrolysis, as described in U.S. Patent No. 5,554,287.

[0092] In some embodiments, a majority (i.e., more than half) of the microfibrils have a lateral dimension (e.g., width in two dimensions) of up to 1 micrometer, up to 1.5 micrometers, up to 2 micrometers, up to 3 micrometers, or up to 4 micrometers. In some embodiments, a majority of the microfibrils have a lateral dimension of at least 0.5 micrometers or at least 0.7 micrometers. In an exemplary embodiment, a majority of the microfibrils have a lateral dimension in the range of 0.5 micrometers to 4 micrometers. In another exemplary embodiment, a majority of the microfibrils have a lateral dimension in the range of 0.5 micrometers to 1.5 micrometers. In yet another exemplary embodiment, a majority of the microfibrils have a lateral dimension of up to 2 micrometers.

[0093] In some embodiments, microfibrillated fibers are incorporated (i.e., distributed throughout) into a fiber medium to form filter media (also referred to herein as "filtration medium" or "filter medium"). Third nonwoven filter media

[0094] The third nonwoven filter media includes “small efficiency fibers”, wherein “small efficiency fibers” as used herein are fibers having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer.

[0095] In some embodiments, the low-efficiency fiber preferably comprises PET. In some embodiments, the low-efficiency fiber may be substantially composed of PET. In some embodiments, the low-efficiency fiber may be composed of PET.

[0096] Alternatively or alternatively, low-efficiency fibers may include nylon, acrylic, rayon, polypropylene, polyethylene, ethylene-vinyl alcohol (EVOH), polylactic acid (PLA), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), or other suitable meltable polymers.

[0097] In some embodiments, in addition to low-efficiency fibers, the third nonwoven filter media may also include fibers and components. These additional fibers and components may include bicomponent fibers, monocomponent heat-fusible fibers, resins, etc.

[0098] When the third nonwoven filter media may include fibers and components other than low-efficiency fibers, the third nonwoven filter media preferably includes 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 low-efficiency fibers. In some embodiments, the third nonwoven filter media includes 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 low-efficiency fibers.

[0099] In some embodiments, the low-efficiency fiber has a fiber diameter of at least 0.1 micrometer, at least 0.2 micrometer, at least 0.3 micrometer, at least 0.4 micrometer, at least 0.5 micrometer, at least 0.6 micrometer, or at least 0.7 micrometer. In some embodiments, the low-efficiency fiber has a fiber diameter of at most 0.7 micrometer, at most 0.8 micrometer, at most 0.9 micrometer, or less than 1 micrometer. For example, in an exemplary embodiment, the low-efficiency fiber has a fiber diameter of at least 0.4 micrometer and less than 1 micrometer. In another exemplary embodiment, the low-efficiency fiber has a fiber diameter in the range of 0.6 micrometer to 0.8 micrometer. In yet another exemplary embodiment, the low-efficiency fiber has a fiber diameter of 0.7 micrometer (700 nm).

[0100] 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 at most 10 mm, at most 11 mm, at most 12 mm, or at most 15 mm. In an exemplary embodiment, the low-efficiency fibers have a length in the range of 1 mm to 15 mm. In another exemplary embodiment, the low-efficiency fibers have a length in the range of 1 mm to 12 mm.

[0101] In one exemplary embodiment, the low-efficiency fiber is a PET fiber with a fiber diameter of 0.7 micrometers.

[0102] In some embodiments, when the low-efficiency fiber comprises PET, the PET of the low-efficiency fiber has a melting point of at least 250°C, more preferably at least 275°C, and even more preferably at least 290°C. support layer

[0103] In some embodiments, the composite material includes a support layer (also known as a loose fabric). Any suitable support layer can be used.

[0104] The support layer may comprise or be made of any suitable porous material. In some embodiments, the support layer may preferably be a polymer.

[0105] 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 woven or nonwoven form. Examples of synthetic nonwovens include polyester nonwovens, nylon nonwovens, polyolefin (e.g., polypropylene) nonwovens, polycarbonate nonwovens, or blends or multicomponent nonwovens thereof. Sheet-like support layers (e.g., cellulose webs, synthetic webs, and / or glass webs or composite 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 spunbond fabrics.

[0106] In some embodiments, the support layer comprises a plurality of fibers or strands. The fibers or strands of the support layer may be continuous or discontinuous. Continuous fibers (e.g., strands) are made by “continuous” fiber-forming processes, such as meltblowing, melt spinning, extrusion, weaving yarns, laying loose fabrics, and / or spunbonding, and typically have a longer length than discontinuous fibers, as described in more detail below. Discontinuous fibers are, for example, short fibers that are typically cut (e.g., from filaments) or formed as discontinuous discrete fibers to have a specific length or length range.

[0107] In some embodiments, the multiple fibers or strands of the support layer comprise synthetic fibers or strands (e.g., synthetic polymer fibers or strands). The synthetic fibers or strands of the support layer may be continuous fibers. Non-limiting examples of suitable synthetic fibers / strands include polyesters, aromatic polyamides, polyimides, polyolefins (e.g., polyethylene such as high-density polyethylene, low-density polyethylene, and / or linear low-density polyethylene), ethylene-vinyl acetate, polyacrylamide, polylactic acid, polypropylene, Kevlar, Nomex, halogenated polymers (e.g., polyethylene terephthalate), acrylic fibers, polyphenylene ether, polyphenylene sulfide, thermoplastic elastomers (e.g., thermoplastic polyurethane), polymethylpentene, and combinations thereof.

[0108] In some embodiments, the average pore size of the support layer is 100 micrometers or less, and typically at least 0.5 micrometers.

[0109] In some embodiments, the porosity of the supporting loose fabric is 20% or greater, and typically does not exceed 90%.

[0110] Exemplary support layers include those available from Midwest Filtering, Cincinnati, Ohio, under the trade names FINON C303NW and FINON C3019 NW, or under the trade name CEREX 23200 (Cerex Advanced Fabrics, Cantoment, Florida). CEREX 23200 comprises nylon 6,6 with a thickness of 8.4 mils (0.21 mm) and a density of 67.8 g / m². 2 Basis weight, 28% density, and a permeability / density of 615.1. Other exemplary loosely woven fabric materials are described, for example, in U.S. Patent Publication 2009 / 0120868. Methods using composite materials

[0111] On the other hand, this disclosure describes methods for using the composite materials described herein.

[0112] In some embodiments, the method of using a composite material includes filtering a liquid stream. For example, such a method may include passing a liquid stream containing contaminants through the composite material and removing the contaminants from the liquid stream.

[0113] Liquid flows may include, for example, fuel, hydraulic oil, process water, air, diesel engine fluid (DEF), diesel engine lubricating oil, leaks, and combinations thereof.

[0114] In some embodiments, the method of using composite materials includes passing a liquid stream through a first nonwoven filter medium, then through a second nonwoven filter medium, and then through a third nonwoven filter medium. Methods for manufacturing composite materials

[0115] In another aspect, this disclosure describes methods for manufacturing composite materials.

[0116] In some embodiments, the first and second nonwoven filter media can be manufactured independently. In some embodiments, the first and third nonwoven filter media can be manufactured independently. In some embodiments, the second and third nonwoven filter media can be manufactured independently. In some embodiments, the first, second, and third nonwoven filter media can be manufactured independently. When the nonwoven filter media are manufactured independently, even if they are formed by the same method, they are not manufactured in the same process. For example, even if each of the three filter media is manufactured using a wet web forming process, if they are manufactured independently, they are formed in three separate wet web forming processes and then placed in contact with each other, rather than being formed in a single wet web forming process.

[0117] In some embodiments, at least one of the first nonwoven filter media, the second nonwoven filter media, and the third nonwoven filter media is formed using a wet web forming process.

[0118] In some embodiments, a method of manufacturing a composite material includes placing a first nonwoven filter medium in contact with a second nonwoven filter medium, or placing the second nonwoven filter medium in contact with a third nonwoven filter medium, or both.

[0119] When the composite material includes a support layer, the method may further include placing a third nonwoven filter medium in contact with the support layer. In some embodiments, the method may include forming the third nonwoven filter medium on the support layer.

[0120] In some embodiments, a method of manufacturing the composite material includes combining a first nonwoven filter medium with a second nonwoven filter medium, or combining a second nonwoven filter medium with a third nonwoven filter medium, or both. Any suitable bonding means may be used, including, for example, lamination. Exemplary composite materials

[0121] A1 is a composite material comprising: a first nonwoven filter medium comprising: 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 microfibrilated fiber, wherein a majority of the microfibrilated fiber has a transverse dimension of a maximum of 4 micrometers; optionally, a second nonwoven filter medium comprising: 40 wt% to 90 wt% of a second bicomponent fiber having a fiber diameter in the range of 5 to 50 micrometers and a fiber length in the range 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 first microfibrilated 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 second high-efficiency fiber; and 10 wt% to 60 wt% of a first microfibrilated fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers; and 10 wt% to 60 wt% of a first microfibrilated fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers and a fiber length in the range of 1.1 cm to 15 cm; 0 wt% to 25 wt% of a second microfibril; and 10 wt% to 60 wt% of a first microfibrilated fiber having a fiber diameter in the range of 1 micrometer to 5 micrometers; and 10 wt% to The composite material comprises wt% of a second microfibril, most of which has a transverse dimension of up to 4 micrometers; and a third nonwoven filter medium comprising small efficiency fibers having a fiber diameter of at least 0.1 micrometers and less than 1 micrometer; wherein the composite material is substantially free of glass fibers.

[0122] Aspect A2 is a composite material as described in aspect A1, wherein the first bicomponent fiber comprises a structural polymer portion and a thermoplastic binder polymer portion, wherein the structural polymer portion has a higher melting point than the binder polymer portion.

[0123] Aspect A3 is a composite material as described in aspects A1 or A2, wherein the second bicomponent fiber comprises a structural polymer portion and a thermoplastic binder polymer portion, wherein the structural polymer portion has a higher melting point than the binder polymer portion.

[0124] Aspect A4 is a composite material as described in aspects A2 or A3, 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 of at most 115°C.

[0125] Aspect A5 is a composite material as described in aspects A2 or A3, 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.

[0126] Aspect A6 is a composite material as described in aspect A5, wherein the binder polymer portion of the bicomponent fiber has a melting point in the range of 140°C to 160°C.

[0127] Aspect A7 is a composite material as described in any one of aspects A1 to A6, wherein the first bicomponent fiber or the second bicomponent fiber comprises at least two different bicomponent fibers.

[0128] Aspect A8 is a composite material as described in any one of aspects A1 to A7, wherein the first nonwoven filter medium comprises 40 wt% to 60 wt% of the first bicomponent fiber.

[0129] Aspect A9 is a composite material as described in any one of aspects A1 to A8, wherein the second nonwoven filter medium comprises 40 wt% to 60 wt% of the second bicomponent fiber.

[0130] Aspect A10 is a composite material as described in any one of aspects A1 to A9, wherein the first high-efficiency fiber has a fiber diameter of 2.7 micrometers.

[0131] Aspect A11 is a composite material as described in any one of aspects A1 to A10, wherein the first high-efficiency fiber comprises PET.

[0132] Aspect A12 is a composite material as described in any one of aspects A1 to A11, wherein the second fiber high-efficiency fiber has a fiber diameter of 2.7 micrometers.

[0133] Aspect A13 is a composite material as described in any one of aspects A1 to A12, wherein the second most efficient fiber comprises PET.

[0134] Aspect A14 is a composite material as described in any one of aspects A1 to A13, wherein the first nonwoven filter medium comprises at least 10 wt% of the first high-efficiency fiber.

[0135] Aspect A15 is a composite material as described in any one of aspects A1 to A14, wherein the second nonwoven filter medium contains at least 10 wt% of the second high-efficiency fiber.

[0136] Aspect A16 is a composite material as described in any one of aspects A1 to A15, wherein most of the microfibrils of the first nonwoven filter medium have a transverse dimension of up to 2 micrometers.

[0137] Aspect A17 is a composite material as described in any one of aspects A1 to A16, wherein most of the microfibrils of the second nonwoven filter medium have a transverse dimension of up to 2 micrometers.

[0138] Aspect A18 is a composite material as described in any one of aspects A1 to A17, wherein most of the microfibrillated fibers of the first nonwoven filter medium have a transverse dimension in the range of 0.5 micrometers to 1.5 micrometers.

[0139] Aspect A19 is a composite material as described in any one of aspects A1 to A18, wherein most of the microfibrillated fibers of the second nonwoven filter medium have a transverse dimension in the range of 0.5 micrometers to 1.5 micrometers.

[0140] Aspect A20 is a composite material as described in any one of aspects A1 to A19, wherein the first nonwoven filter medium comprises 10 wt% to 40 wt% microfibrillated fibers.

[0141] Aspect A21 is a composite material as described in any one of aspects A1 to A20, wherein the second nonwoven filter medium comprises 10 wt% to 40 wt% microfibrillated fibers.

[0142] Aspect A22 is a composite material as described in any one of aspects A1 to A21, wherein the first nonwoven filter medium has a solidity in the range of 5% to 15%.

[0143] A23 is a composite material as described in any one of A1 to A22, wherein the first nonwoven filter medium has a density of 24 g / m³. 2 Up to 100 g / m 2 Basis weight within the range.

[0144] Aspect A24 is a composite material as described in any one of aspects A1 to A23, wherein the first nonwoven filter medium has a pore size of 0.5 micrometers to 20 micrometers.

[0145] Aspect A25 is a composite material as described in any one of aspects A1 to A24, wherein the first nonwoven filter medium has a thickness in the range of 0.12 mm to 1 mm.

[0146] A26 is a composite material as described in any one of A1 to A25, wherein the first nonwoven filter medium has a filtration efficiency of 1 ft underwater at 0.5 inches. 3 / ft 2 / min to 100 ft at 0.5 inches underwater 3 / ft 2 Permeability within the range of / min.

[0147] Aspect A27 is a composite material as described in any one of aspects A1 to A26, wherein the second nonwoven filter medium has a solidity in the range of 5% to 15%.

[0148] A28 is a composite material as described in any one of A1 to A27, wherein the second nonwoven filter medium has a density of 24 g / m³. 2 Up to 100 g / m 2 Basis weight within the range.

[0149] Aspect A29 is a composite material as described in any one of aspects A1 to A28, wherein the second nonwoven filter medium has a pore size of 0.5 micrometers to 20 micrometers.

[0150] Aspect A30 is a composite material as described in any one of aspects A1 to A29, wherein the second nonwoven filter medium has a thickness in the range of 0.12 mm to 1 mm.

[0151] Aspect A31 is a composite material as described in any one of aspects A1 to A30, wherein the second nonwoven filter media has a filtration efficiency of 1 ft underwater at 0.5 inches. 3 / ft 2 / min to 100 ft at 0.5 inches underwater 3 / ft 2 Permeability within the range of / min.

[0152] Aspect A32 is a composite material as described in any one of aspects A1 to A31, wherein the low-efficiency fiber has a fiber diameter of at least 0.4 micrometers and less than 1 micrometer.

[0153] Aspect A33 is a composite material as described in any one of aspects A1 to A32, wherein the low-efficiency fiber has a fiber diameter in the range of 0.6 micrometers to 0.8 micrometers.

[0154] Aspect A34 is a composite material as described in any one of aspects A1 to A33, wherein the low-efficiency fiber comprises fibers having a fiber diameter of 0.7 micrometers.

[0155] Aspect A35 is a composite material as described in any one of aspects A1 to A34, wherein the low-efficiency fiber PET comprises polyethylene terephthalate (PET).

[0156] Aspect A36 is a composite material as described in any one of aspects A1 to A35, wherein the composite material is substantially resin-free.

[0157] Aspect A37 is a composite material as described in any one of aspects A1 to A36, wherein the composite material does not contain glass fibers.

[0158] Aspect A38 is a composite material as described in any one 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.

[0159] Aspect A39 is a composite material as described in any one of aspects A1 to A38, 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.

[0160] Aspect A40 is a composite material as described in any one of aspects A1 to A39, wherein the nonwoven filter medium further comprises a support layer.

[0161] A41 is a composite material as described in aspect A40, wherein the support layer comprises a porous polymer material.

[0162] Aspect A42 is a composite material as described in aspects A40 or A41, 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, then through the third nonwoven filter medium, and then through the support layer.

[0163] Aspect A43 is a composite material as described in any one of aspects A40 to A42, wherein the third nonwoven filter medium is in contact with the support layer.

[0164] Aspect A44 is a composite material as described in any one of aspects A1 to A43, wherein 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.

[0165] Aspect A45 is a composite material as described in any one 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.

[0166] Aspect A46 is a composite material as described in any one 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.

[0167] Aspect A47 is a composite material as described in any one of aspects A1 to A46, wherein the microfibrillated fibers of the first nonwoven filter medium comprise microfibrillated cellulose fibers.

[0168] Aspect A48 is a composite material as described in any one of aspects A1 to A47, wherein the microfibrillated fibers of the second nonwoven filter medium include microfibrillated cellulose fibers. Exemplary methods using composite materials

[0169] Aspect B1 is a method for filtering a liquid stream, the method comprising passing a liquid stream containing a contaminant through a composite material of any one of the "Exemplary Composite Material Aspects" (Aspects A1 to A48) and removing the contaminant from the liquid stream.

[0170] Aspect B2 is the method as described in aspect B1, wherein the liquid flow includes fuel, hydraulic oil, process water, air, diesel engine fluid (DEF), diesel engine lubricating oil, or leaks or combinations thereof.

[0171] Aspect B3 is the method as described in aspects B1 or B2, wherein the liquid is passed through the first nonwoven filter medium, then through the second nonwoven filter medium, and then through the third nonwoven filter medium. Exemplary methods for manufacturing composite materials

[0172] Aspect C1 is a method of manufacturing a composite material according to any one of the "Exemplary Composite Material Aspects" (Aspects A1 to A48), the method comprising independently manufacturing the first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium.

[0173] Aspect C2 is the method as described in aspect C1, wherein the first nonwoven filter medium, the second nonwoven filter medium, and the third nonwoven filter medium are formed using a wet web forming process.

[0174] Aspect C3 is the method as described in aspects C1 or C2, the method further comprising placing the first nonwoven filter medium in contact with the second nonwoven filter medium, or placing the second nonwoven filter medium in contact with the third nonwoven filter medium.

[0175] Aspect C4 is the method as described in aspect C3, the method further comprising combining the first nonwoven filter medium with the second nonwoven filter medium, or combining the second nonwoven filter medium with the third nonwoven filter medium, or both.

[0176] Aspect C5 is the method as described in aspect C4, wherein the combination includes lamination.

[0177] Aspect C6 is the method as described in any one of aspects C1 to C5, the method further comprising placing the third nonwoven filter medium in contact with the support layer.

[0178] The present invention is illustrated by the following examples. It should be understood that specific examples, materials, quantities, and procedures should be interpreted broadly in accordance with the scope and spirit of the invention as set forth herein. Example

[0179] All reagents, starting materials, and solvents used in the following examples were purchased from commercial suppliers (e.g., Sigma-Aldrich, St. Louis, Missouri) and, unless otherwise specified, can be used without further purification. Medium characterization Liquid filtration performance test

[0180] The pressure difference and β (β) were calculated using a circular plate. 4 µm The test medium is as described in ISO 16889:2008 (Hydraulic fluid power — Filters — Multi-pass method for evaluating the filtration performance of a filter element), except that the hydraulic fluid is loaded with ISO fine test dust instead of ISO medium test dust. The medium area is 0.0507 m². 2 The test flow rate was 2 L / min, and the test was conducted up to a terminal element pressure difference of 200 kPa. Reality

[0181] The solidity (c) of nonwoven layers (including, for example, non-fiber layers or composites comprising both fiber and non-fiber layers) is calculated using the following equation: c = BW / ρZ.

[0182] Where BW is the basis weight, ρ is the fiber density, and Z is the thickness of the medium.

[0183] Measure thickness according to TAPPI T411 om-15, titled "Thickness (caliper) of paper, paperboard, and combined board"; use a foot pressure of 1.5 psi. Measure basis weight using TAPPI T410. Example 1

[0184] This example illustrates the improved efficiency and lifespan achieved by using composite materials that include a layer of fine fibers.

[0185] Preparation of a plate comprising a loosely woven cloth (1 oz / yd) 2 Polyester (sold under the trade name Reemay) and Synteq® 10XP overlaid on a loosely woven fabric (Donaldson Company, Inc., Minneapolis, Minnesota) Figure 2A (left image), or use the same loosely woven fabric (with 1 µm diameter fine fibers having an electrospun layer on it) and Synteq® 10XP superimposed on the fine fiber layer ( Figure 2A (See right image).

[0186] like Figure 1A As shown, adding a microfiber layer improves the load capacity (i.e., lifespan) of the plate compared to a plate without a microfiber layer. Figure 1B As shown, adding a fiber layer improves the efficiency of the plate compared to a plate without a fiber layer.

[0187] These results were unexpected, as it had been previously reported that creating interfaces between dielectric layers was undesirable, and instead, gradient structures should be pursued. See, for example US Publication No. 2014 / 0360145.

[0188] Not wanting to be bound by theory, it is believed that creating interfaces between dielectric layers could allow for higher efficiency, since the inhomogeneity of each layer is not consistent throughout the depth of the dielectric. Example 2

[0189] In a flat sheet comprising a loosely woven fabric, a 700 nm diameter PET fiber layer, and a handsheet prepared as described in Example 1, the same improvement in loading capacity and efficiency reported in Example 1 is expected. This handsheet comprises 40%–60% bicomponent fibers with a diameter of 14 µm, 0%–25% PET fibers with a diameter of 2.5 µm, and 10%–40% fibrillated rayon fibers with a diameter of 1 µm. Figure 2B ).

[0190] Without being bound by theory, it is believed that the 700 nm diameter PET fiber layer will act as the efficiency layer, and the hand-copied sheet will act as the load layer. Variable efficiency (which would otherwise be observed if the hand-copied sheet were used alone) is expected to be eliminated by combining it with the 700 nm diameter PET fiber (acting as the efficiency layer).

[0191] Not wanting to be bound by theory, it is believed that creating interfaces between dielectric layers could allow for higher efficiency, since the inhomogeneity of each layer is not consistent throughout the depth of the dielectric.

[0192] All disclosures of patents, patent applications, publications, and materials available electronically in connection with this application are incorporated herein by reference. In the event of any discrepancy between the disclosures in this application and those in any other document incorporated herein by reference, the disclosures in this application shall prevail. The detailed descriptions and examples above are provided for clarity only and should not be construed as unnecessarily limiting. The invention is not limited to the precise details shown and described, and variations that will be apparent to those skilled in the art will be included within the scope of the invention as defined by the claims.

Claims

1. A glass-free filter 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; The second nonwoven filter medium comprises small-efficiency fibers with a fiber diameter of at least 0.1 micrometers and less than 1 micrometer; as well as Support layer.

2. The composite material according to claim 1 further includes a third nonwoven filter medium, wherein the third nonwoven filter medium is disposed between the first nonwoven filter medium and the second nonwoven filter medium, and the third nonwoven filter medium 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 The second microfibrillated fiber comprises 10 wt% to 60 wt% of a microfibrillated fiber, wherein most of the microfibrillated fiber has a transverse dimension of up to 4 micrometers.

3. The composite material according to 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.

4. The composite material according to claim 1 or 2, wherein the first high-efficiency fiber comprises polyethylene terephthalate (PET), or wherein the second high-efficiency fiber comprises PET, or wherein the first high-efficiency fiber comprises PET and the second high-efficiency fiber comprises PET.

5. The composite material according to claim 1, wherein, Small efficiency fibers have a fiber diameter in the range of 0.6 micrometers to 0.8 micrometers.

6. The composite material according to claim 1 or 5, wherein, Low-efficiency fibers include polyethylene terephthalate (PET).

7. The composite material according to claim 1, wherein, Composite materials contain virtually no resin.

8. The composite material according to claim 2, wherein, The first, second, and third nonwoven filter media are discrete layers.

9. The composite material according to claim 2, wherein, The nonwoven filter media are configured to allow liquid to pass through a first nonwoven filter media, then through a second nonwoven filter media, and then through a third nonwoven filter media.

10. The composite material according to claim 1, wherein, The third nonwoven filter media comes into contact with the support layer.

11. The composite material according to claim 1 or 2, wherein, The first microfibrillated fiber or the second microfibrillated fiber, or both, may include microfibrillated cellulose fibers.

12. A method for filtering a liquid stream, the method comprising: To allow a liquid containing contaminants to flow through the composite material of claim 1 or 2, and Remove contaminants from the liquid stream.

13. The method according to claim 12, wherein, The liquid flow includes air.

14. A method for manufacturing the composite material as claimed in claim 2, the method comprising: The first nonwoven filter media, the second nonwoven filter media, and the third nonwoven filter media are manufactured independently.

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