coalescing filter media

Abstract

The filter media are described in general. In some embodiments, the filter media has one or more properties that enhance its suitability for use in coalescing filters. For example, the filter media may have a particularly low pressure drop and / or may have a particularly high efficiency. In some cases, such properties can be obtained without containing fluorinated materials, regulated substances, and / or toxic substances (e.g., PFAS), or by containing no more than trace amounts of such substances.

Description

Technical Field

[0001] This disclosure relates generally to filter media, and more particularly to filter media suitable for coalescing applications. Background Technology

[0002] Filter media can be used in a variety of applications. For example, filter media can be used to remove contaminants from fluids. Some filter media may contain undesirable components (e.g., government-regulated components) and / or exhibit undesirable properties (e.g., low efficiency and / or high pressure drop).

[0003] Therefore, improved filter media design is needed. Summary of the Invention

[0004] The filter media, related components, and related methods are described in general.

[0005] In some embodiments, a filter medium is provided. The filter medium comprises a fiber web containing glass fibers and resin. The coalescing γ value of the fiber web is less than or equal to 30. The area weight of the fiber web is greater than or equal to 130 gsm. The fiber web is oleophilic.

[0006] In some embodiments, a filter medium is provided comprising a fiber web containing glass fibers. The fiber web has a weight per unit area greater than or equal to 130 gsm. The fiber web comprises pores. Pores with a diameter less than 1.25 micrometers account for less than or equal to 30% of the total pores. Pores with a diameter greater than or equal to 1.25 micrometers and less than 2.5 micrometers account for more than or equal to 40% of the total pores. The ratio of the number of pores with a diameter less than 1.25 micrometers to the number of pores with a diameter greater than or equal to 1.25 micrometers and less than 2.5 micrometers is less than or equal to 1.

[0007] Other advantages and novel features of the invention will become apparent when considered in conjunction with the accompanying drawings, based on the following detailed description of several non-limiting embodiments. Where this specification and any documents incorporated by reference contain conflicting and / or inconsistent disclosures, this specification shall prevail. If two or more documents incorporated by reference contain disclosures that conflict and / or are inconsistent with each other, the document with the later effective date shall prevail. Attached Figure Description

[0008] Non-limiting embodiments of the invention will be described by way of example with reference to the accompanying drawings, which are schematic and not intended to be drawn to scale. In the drawings, each identical or substantially identical component shown is generally indicated by a single reference numeral. For clarity, not every component is labeled in every drawing, nor is every component of every embodiment of the invention shown, where illustration is not required to enable those skilled in the art to understand the invention. In the drawings:

[0009] Figure 1 and Figure 2 Two non-limiting embodiments of the filter medium according to some implementation schemes are shown; and

[0010] Figures 3 to 4 A schematic diagram of foam laying is shown according to some implementation schemes. Detailed Implementation

[0011] The filter media are described in general. In some embodiments, the filter media has one or more properties that enhance its suitability for use in coalescing filters. For example, the filter media may have a particularly low pressure drop and / or may have a particularly high efficiency. In some cases, such properties can be obtained without containing fluorinated materials, regulated substances, and / or toxic substances (e.g., PFAS), or by containing no more than trace amounts of such substances.

[0012] Some filter media described herein include fiber webs with a porous structure, such that the amount and / or relative amount of pores with a specific size is advantageous. For example, the fiber web may have a relatively low number and / or percentage of pores so small that it excessively increases the pressure drop. As another example, the fiber web may have a relatively low number and / or percentage of pores so large that it excessively reduces efficiency. As a third example, in some embodiments, the fiber web has a relatively high number and / or percentage of pores large enough to maintain an acceptable pressure drop but small enough to maintain acceptable efficiency.

[0013] Some of the filter media described in this article include fiber webs with a relatively high weight per unit area. Including individual fiber webs with a relatively high weight per unit area can produce advantages that filter media with multiple lighter fiber webs do not offer, such as improved performance.

[0014] Some of the filter media described herein include fiber webs that are both relatively high in weight per unit area and wet-laid. Without being bound by any particular theory, it is thought that during wet lamination, a fiber web is formed as liquid is removed from the fiber-containing liquid. When the liquid is removed, it can affect the orientation and / or compression of the fibers in the final fiber web. It is also thought that wet lamination of fiber webs with relatively high weight per unit area involves removing liquid in a manner that promotes the formation of a pore structure with a favorable pore size distribution as described herein.

[0015] Some of the filter media described herein are relatively oleophilic and / or contain one or more relatively oleophilic components. Such components can advantageously be free of oleophobic components regulated by government agencies, while still exhibiting acceptable coalescing performance.

[0016] Figure 1 A non-limiting embodiment of the filter medium is shown. Figure 1 In this document, the filter medium 100 includes a fiber web 102. The fiber web described herein is similar to... Figure 1 Like the fiber web shown, it can be made of nonwoven fibers, such as wet-laid fiber webs.

[0017] In some embodiments, the filter medium includes one or more layers in addition to the fiber web, such as one or more additional fiber webs (e.g., one or more nonwoven fiber webs). In some embodiments, the filter medium includes an additional layer as a protective layer. Figure 2 A non-limiting embodiment of such a filter medium is shown. Figure 2 In this filter medium 200, a fiber web 202 (e.g., a first fiber web) and an additional layer 204 (e.g., a second fiber web) may be present. Optional additional fiber webs (not shown) (e.g., a third fiber web, a fourth fiber web, a fifth fiber web, etc.) may also be present.

[0018] In some embodiments, adjacent layers may be physically distinct from each other and / or physically separable without the use of specialized tools. Similarly, adjacent fiber webs may be physically distinct from each other and / or physically separable without the use of specialized tools. In some embodiments, two adjacent layers and / or fiber webs may include an interface therebetween, the interface representing two separate layers adjacent to each other across the interface. Some such interfaces can be observed by microscopy (e.g., by scanning electron microscopy) and / or density gradient structure analysis. Monolayers and / or fiber webs may not be separable into two or more components without the use of specialized tools, and / or may lack such interfaces.

[0019] In embodiments that include multiple additional layers (e.g., comprising one or more additional fiber webs), the positioning of the additional layers can be selected as desired. In some embodiments, all additional layers are positioned on one side of the fiber web (e.g., the fiber web is the outer layer). In some embodiments, the fiber web is surrounded by additional layers on two opposite sides (e.g., the fiber web is the inner layer).

[0020] The filter medium may comprise two or more layers that are identical to each other (e.g., two or more fiber webs that are identical to each other) and / or may comprise two or more layers that are different from each other in one or more respects. Furthermore, it should be understood that the fiber webs described herein may have some, all, or none of the features described herein.

[0021] It should also be noted that some filter media described herein may include one or more multiphase fiber webs. For example, the fiber web present in the filter media may include two or more phases that are interwoven and / or mixed with each other. For example, in some embodiments of the multiphase fiber web, the fiber web includes an interface between a first phase and a second phase, and the interface includes at least some fibers from the first phase that are mixed with and / or entangled with at least some fibers from the second phase. In some embodiments, the interface includes each of the fibers from the first phase that is mixed with and / or entangled with each of the fibers from the second phase. In some embodiments, the interface may take the form of a transitional phase between the first and second phases. The interface may also be substantially nonlinear and / or substantially free of (e.g., free of) adhesives. In some embodiments, the two phases are not joined by lamination.

[0022] In some cases, despite possessing one or more of the above characteristics, multiphase fiber webs comprise two or more phases that cannot be physically separated without the use of specialized tools. In such cases, the physical interactions between fibers within the phases may be sufficient to bind the phases together. Similarly, in some embodiments, multiphase fiber webs include an interface between two phases, which can be observed using the techniques described above for observing the interface between two adjacent fiber webs, but the type of this interface is significantly different from that between two adjacent fiber webs.

[0023] The type and arrangement of phases in a multiphase fiber web can be selected as desired. Some multiphase fiber webs include a single phase layered on top of another. Each phase in a multiphase fiber web may have one or more distinct characteristics (e.g., fiber type, average fiber diameter, pore structure, etc.) and may also have one or more common characteristics.

[0024] In some embodiments, the fiber web comprises glass fibers. In such cases, the amount of glass fibers present in the fiber web can be selected as desired. The glass fibers may constitute greater than or equal to 0.1 wt%, greater than or equal to 0.2 wt%, greater than or equal to 0.5 wt%, greater than or equal to 0.75 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 5 wt%, greater than or equal to 7.5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, greater than or equal to 20 wt%, greater than or equal to 25 wt%, greater than or equal to 30 wt%, greater than or equal to 35 wt%, greater than or equal to 40 wt%, greater than or equal to 45 wt%, greater than or equal to 50 wt%, greater than or equal to 55 wt%, greater than or equal to 60 wt%, greater than or equal to 65 wt%, greater than or equal to 70 wt%, greater than or equal to 75 wt%, greater than or equal to 80 wt%, greater than or equal to 85 wt%, greater than or equal to 90 wt%, greater than or equal to 95 wt%, greater than or equal to 99 wt%, or greater than or equal to 99.5 wt%. Glass fiber may comprise less than or equal to 99.9% by weight, less than or equal to 99.5% by weight, less than or equal to 90% by weight, less than or equal to 85% by weight, less than or equal to 80% by weight, less than or equal to 75% by weight, less than or equal to 70% by weight, less than or equal to 65% by weight, less than or equal to 60% by weight, less than or equal to 55% by weight, less than or equal to 50% by weight, less than or equal to 45% by weight, less than or equal to 40% by weight, less than or equal to 35% by weight, less than or equal to 30% by weight, less than or equal to 25% by weight, less than or equal to 20% by weight, less than or equal to 15% by weight, less than or equal to 10% by weight, less than or equal to 7.5% by weight, less than or equal to 5% by weight, less than or equal to 2% by weight, less than or equal to 1% by weight, less than or equal to 0.75% by weight, less than or equal to 0.5% by weight, or less than or equal to 0.2% by weight. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1% by weight and less than or equal to 99.9% by weight, greater than or equal to 0.5% by weight and less than or equal to 99.5% by weight, or greater than or equal to 1% by weight and less than or equal to 99% by weight). Other ranges are also possible.

[0025] When two or more types of glass fibers are present in a fiber web and / or phase, the amount of each type of glass fiber present in the fiber web and / or phase may independently fall within one or more of the above-mentioned ranges, and / or all glass fibers may be present together in amounts within one or more of the above-mentioned ranges. When two or more fiber webs and / or phases containing glass fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0026] The glass fibers present in the fiber web can have a variety of suitable average diameters. In some embodiments, the average diameter of the glass fibers present in the fiber web and / or phase is greater than or equal to 0.2 μm, greater than or equal to 0.5 μm, greater than or equal to 0.75 μm, greater than or equal to 1 μm, greater than or equal to 2 μm, greater than or equal to 4 μm, greater than or equal to 6 μm, or greater than or equal to 8 μm. In some embodiments, the average diameter of the glass fibers present in the fiber web and / or phase is less than or equal to 10 μm, less than or equal to 8 μm, less than or equal to 6 μm, less than or equal to 4 μm, less than or equal to 2 μm, less than or equal to 1 μm, less than or equal to 0.75 μm, or less than or equal to 0.5 μm. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.2 μm and less than or equal to 10 μm, greater than or equal to 0.2 μm and less than or equal to 8 μm, or greater than or equal to 0.2 μm and less than or equal to 6 μm). Other ranges are also possible.

[0027] When two or more types of glass fibers are present in a fiber web and / or phase, the average diameter of each type of glass fiber present in the fiber web and / or phase may independently fall within one or more of the aforementioned ranges, and / or all glass fibers may together have an average diameter within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing glass fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0028] The glass fibers present in the fiber web can have various suitable average lengths. In some embodiments, the average length of the glass fibers present in the fiber web and / or phase is greater than or equal to 0.1 mm, greater than or equal to 0.2 mm, greater than or equal to 0.5 mm, greater than or equal to 0.75 mm, greater than or equal to 1 mm, greater than or equal to 1.5 mm, greater than or equal to 2 mm, or greater than or equal to 2.5 mm. In some embodiments, the average length of the glass fibers present in the fiber web and / or phase is less than or equal to 3 mm, less than or equal to 2.5 mm, less than or equal to 2 mm, less than or equal to 1.5 mm, less than or equal to 1 mm, less than or equal to 0.75 mm, less than or equal to 0.5 mm, or less than or equal to 0.2 mm. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1 mm and less than or equal to 3 mm, greater than or equal to 0.1 mm and less than or equal to 2 mm, or greater than or equal to 0.1 mm and less than or equal to 1.5 mm). Other ranges are also possible.

[0029] When two or more types of glass fibers are present in a fiber web and / or phase, the average length of each type of glass fiber present in the fiber web and / or phase may independently fall within one or more of the aforementioned ranges, and / or all glass fibers may together have an average length within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing glass fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0030] Various suitable glass fibers can be used in the fiber webs described herein. For example, in some embodiments, the fiber web comprises ultrafine glass fibers. Ultrafine glass fibers can include ultrafine glass fibers drawn from a spinneret nozzle and further subjected to flame blowing or rotary spinning processes. In some cases, ultrafine glass fibers can be manufactured using a remelting method. Ultrafine glass fibers can be ultrafine glass fibers in which alkali metal oxides (e.g., sodium oxide, magnesium oxide) constitute 10% to 20% by weight of the fiber. Such fibers can have relatively low melting and processing temperatures. Non-limiting examples of ultrafine glass fibers include B glass fibers, M glass fibers, C glass fibers (e.g., Lauscha C glass fibers, JM 253 C glass fibers), and non-persistent glass fibers (e.g., fibers configured to completely dissolve in fluids present in the human lungs within 40 days or less). It should be understood that ultrafine glass fibers present in a fiber web may include one or more of the types of ultrafine glass fibers described herein.

[0031] In some embodiments, the fiber web comprises synthetic fibers. In such cases, the amount of synthetic fibers present in the fiber web and / or phase can be selected as desired. Synthetic fibers may constitute greater than or equal to 0.1 wt%, greater than or equal to 0.2 wt%, greater than or equal to 0.5 wt%, greater than or equal to 0.75 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 5 wt%, greater than or equal to 7.5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, greater than or equal to 20 wt%, greater than or equal to 25 wt%, greater than or equal to 30 wt%, greater than or equal to 35 wt%, greater than or equal to 40 wt%, or greater than or equal to 45 wt%. Synthetic fibers may comprise less than or equal to 50% by weight, less than or equal to 45% by weight, less than or equal to 40% by weight, less than or equal to 35% by weight, less than or equal to 30% by weight, less than or equal to 25% by weight, less than or equal to 20% by weight, less than or equal to 15% by weight, less than or equal to 10% by weight, less than or equal to 7.5% by weight, less than or equal to 5% by weight, less than or equal to 2% by weight, less than or equal to 1% by weight, less than or equal to 0.75% by weight, less than or equal to 0.5% by weight, or less than or equal to 0.2% by weight. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1% by weight and less than or equal to 50% by weight, greater than or equal to 0.5% by weight and less than or equal to 40% by weight, or greater than or equal to 1% by weight and less than or equal to 30% by weight). Other ranges are also possible.

[0032] When two or more types of synthetic fibers are present in a fiber web and / or phase, the amount of each type of synthetic fiber present in the fiber web and / or phase may independently fall within one or more of the aforementioned ranges, and / or all synthetic fibers may be present together in amounts within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing synthetic fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0033] Various suitable types of synthetic fibers can be used in the fiber webs described herein. Non-limiting examples of types of synthetic fibers that can be included in the fiber webs described herein include staple fibers, adhesive fibers, and multicomponent fibers. The fiber webs may contain single-component adhesive fibers and / or multicomponent adhesive fibers (e.g., bicomponent adhesive fibers, tricomponent adhesive fibers, adhesive fibers containing four or more components).

[0034] The synthetic fibers (e.g., short synthetic fibers) present in the fiber web, excluding the bonding fibers, can have a variety of suitable average diameters. In some embodiments, the average diameter of the synthetic fibers (excluding the bonding fibers) present in the fiber web and / or phase is greater than or equal to 3 micrometers, greater than or equal to 4 micrometers, greater than or equal to 5 micrometers, greater than or equal to 7.5 micrometers, greater than or equal to 10 micrometers, greater than or equal to 12.5 micrometers, greater than or equal to 15 micrometers, greater than or equal to 17.5 micrometers, greater than or equal to 20 micrometers, or greater than or equal to 22.5 micrometers. In some embodiments, the average diameter of the synthetic fibers (excluding the bonding fibers) present in the fiber web and / or phase is less than or equal to 25 micrometers, less than or equal to 22.5 micrometers, less than or equal to 20 micrometers, less than or equal to 17.5 micrometers, less than or equal to 15 micrometers, less than or equal to 12.5 micrometers, less than or equal to 10 micrometers, less than or equal to 7.5 micrometers, less than or equal to 5 micrometers, or less than or equal to 4 micrometers. Combinations of the above ranges are also possible (e.g., greater than or equal to 3 micrometers and less than or equal to 25 micrometers, greater than or equal to 4 micrometers and less than or equal to 20 micrometers, or greater than or equal to 5 micrometers and less than or equal to 15 micrometers). Other ranges are also possible.

[0035] When two or more types of synthetic fibers other than bonding fibers are present in a fiber web and / or phase, the average diameter of each type of such synthetic fiber present in the fiber web and / or phase may independently fall within one or more of the aforementioned ranges, and / or all such synthetic fibers may together have an average diameter within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing such synthetic fibers are present, the foregoing sentence may apply independently to each such fiber web and / or phase.

[0036] The synthetic fibers (e.g., short synthetic fibers) present in the fiber web, excluding the bonding fibers, can have various suitable average lengths. In some embodiments, the average length of the synthetic fibers (excluding the bonding fibers) present in the fiber web and / or phase is greater than or equal to 2 mm, greater than or equal to 5 mm, greater than or equal to 7.5 mm, greater than or equal to 10 mm, greater than or equal to 12.5 mm, greater than or equal to 15 mm, greater than or equal to 17.5 mm, greater than or equal to 20 mm, or greater than or equal to 22.5 mm. In some embodiments, the average length of the synthetic fibers (excluding the bonding fibers) present in the fiber web and / or phase is less than or equal to 25 mm, less than or equal to 22.5 mm, less than or equal to 20 mm, less than or equal to 17.5 mm, less than or equal to 15 mm, less than or equal to 12.5 mm, less than or equal to 10 mm, less than or equal to 7.5 mm, or less than or equal to 5 mm. Combinations of the above ranges are also possible (e.g., greater than or equal to 2 mm and less than or equal to 25 mm, greater than or equal to 2 mm and less than or equal to 20 mm, or greater than or equal to 2 mm and less than or equal to 15 mm). Other ranges are also possible.

[0037] When two or more types of synthetic fibers other than bonding fibers are present in a fiber web and / or phase, the average length of each type of such synthetic fiber may independently fall within one or more of the aforementioned ranges, and / or all such synthetic fibers may together have an average length within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing such synthetic fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0038] Synthetic staple fibers can contain a variety of materials, including but not limited to poly(esters) (e.g., poly(ethylene terephthalate), poly(butylene terephthalate)), poly(carbonate), poly(amides) (e.g., various nylon polymers), poly(aramids), poly(imides), poly(olefins) (e.g., poly(ethylene), poly(propylene)), poly(ether ether ketones), poly(acrylic acids) (e.g., poly(acrylonitrile), dry-spun (polyacrylic acid)), poly(vinyl alcohol), regenerated cellulose (e.g., synthetic cellulose such as cellulose acetate, rayon), copolymers of poly(ethylene) and PVDF, and poly(ether sulfone).

[0039] The amount of bonding fibers present in the fiber web can be selected as desired. Bonding fibers can account for ≥0% by weight, ≥1% by weight, ≥2% by weight, ≥3% by weight, ≥4% by weight, ≥5% by weight, ≥6% by weight, ≥7% by weight, ≥8% by weight, ≥9% by weight, or ≥9.3% by weight in the fiber web and / or its phase. Bonding fibers can account for ≤9.5% by weight, ≤9.3% by weight, ≤9% by weight, ≤8% by weight, ≤7% by weight, ≤6% by weight, ≤5% by weight, ≤4% by weight, ≤3% by weight, ≤2% by weight, or ≤1% by weight in the fiber web and / or its phase. Combinations of the above ranges are also possible (e.g., ≥0% by weight and ≤9.5% by weight, ≥0% by weight and ≤9.3% by weight, or ≥0% by weight and ≤9% by weight). Other ranges are also possible. In some implementations, the bonding fibers comprise exactly 0% by weight of the fiber web and / or its phase.

[0040] When two or more types of bonding fibers are present in a fiber web and / or phase, the amount of each type of bonding fiber in the fiber web and / or phase may independently be within one or more of the above-mentioned ranges, and / or all bonding fibers may be present together in amounts within one or more of the above-mentioned ranges. When two or more fiber webs and / or phases containing bonding fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0041] The bonding fibers present in the fiber web can have various suitable average diameters. In some embodiments, the average diameter of the bonding fibers present in the fiber web and / or phase is greater than or equal to 1 micrometer, greater than or equal to 2 micrometers, greater than or equal to 3 micrometers, greater than or equal to 4 micrometers, greater than or equal to 5 micrometers, greater than or equal to 7.5 micrometers, greater than or equal to 10 micrometers, greater than or equal to 15 micrometers, greater than or equal to 20 micrometers, greater than or equal to 25 micrometers, greater than or equal to 30 micrometers, or greater than or equal to 35 micrometers. In some embodiments, the average diameter of the bonding fibers present in the fiber web and / or phase is less than or equal to 40 micrometers, less than or equal to 35 micrometers, less than or equal to 30 micrometers, less than or equal to 25 micrometers, less than or equal to 20 micrometers, less than or equal to 15 micrometers, less than or equal to 10 micrometers, less than or equal to 7.5 micrometers, less than or equal to 5 micrometers, less than or equal to 4 micrometers, less than or equal to 3 micrometers, or less than or equal to 2 micrometers. Combinations of the above ranges are also possible (e.g., greater than or equal to 1 micrometer and less than or equal to 40 micrometers, greater than or equal to 2 micrometers and less than or equal to 35 micrometers, or greater than or equal to 2 micrometers and less than or equal to 30 micrometers). Other ranges are also possible.

[0042] When two or more types of bonding fibers are present in a fiber web and / or phase, the average diameter of each type of bonding fiber present in the fiber web and / or phase may independently fall within one or more of the aforementioned ranges, and / or all bonding fibers may together have an average diameter within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing bonding fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0043] The bonding fibers present in the fiber web can have various suitable average lengths. In some embodiments, the average length of the bonding fibers present in the fiber web and / or phase is greater than or equal to 2 mm, greater than or equal to 5 mm, greater than or equal to 7.5 mm, greater than or equal to 10 mm, greater than or equal to 12.5 mm, greater than or equal to 15 mm, greater than or equal to 17.5 mm, greater than or equal to 20 mm, or greater than or equal to 22.5 mm. In some embodiments, the average length of the bonding fibers present in the fiber web and / or phase is less than or equal to 25 mm, less than or equal to 22.5 mm, less than or equal to 20 mm, less than or equal to 17.5 mm, less than or equal to 15 mm, less than or equal to 12.5 mm, less than or equal to 10 mm, less than or equal to 7.5 mm, or less than or equal to 5 mm. Combinations of the above ranges are also possible (e.g., greater than or equal to 2 mm and less than or equal to 25 mm, greater than or equal to 2 mm and less than or equal to 20 mm, or greater than or equal to 2 mm and less than or equal to 15 mm). Other ranges are also possible.

[0044] When two or more types of bonding fibers are present in a fiber web and / or phase, the average length of each type of bonding fiber may independently fall within one or more of the aforementioned ranges, and / or all bonding fibers may together have an average length within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing bonding fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0045] Non-limiting examples of suitable materials that can be included in synthetic adhesive fibers include: poly(vinyl alcohol); poly(olefins), such as poly(ethylene), poly(propylene), and poly(butene); poly(esters) and copoly(esters), such as poly(ethylene terephthalate), copoly(ethylene terephthalate), poly(butylene terephthalate), and poly(ethylene isophthalate); poly(amides) and copoly(amides), such as nylon and aromatic polyamides; epoxy resins; phenolic resins; and melamine. Suitable copoly(ethylene terephthalate) may comprise repeating units formed by the polymerization of polyethylene terephthalate monomers, and may also comprise repeating units formed by the polymerization of one or more comonomers. Such comonomers may include linear, cyclic, and branched aliphatic dicarboxylic acids having 4 to 12 carbon atoms (e.g., succinic acid, glutaric acid, adipic acid, dodecanoic acid, and 1,4-cyclohexanedicarboxylic acid); aromatic dicarboxylic acids having 8 to 12 carbon atoms (e.g., isophthalic acid and 2,6-naphthalenedicarboxylic acid); linear, cyclic, and branched aliphatic diols having 3 to 8 carbon atoms (e.g., 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, and 1,4-cyclohexanediol); and / or aliphatic ether diols and aromatic / aliphatic ether diols having 4 to 10 carbon atoms (e.g., hydroquinone bis(2-hydroxyethyl) ether and those with a molecular weight of less than 460). g / mol of poly(vinyl ether) glycol, such as diethylene ether glycol.

[0046] Synthetic multicomponent fibers can include bicomponent fibers (i.e., fibers containing two components), tricomponent fibers (i.e., fibers containing three components), and / or fibers containing four or more components. Multicomponent fibers can have a variety of suitable structures. For example, the fiber web and / or phase can contain one or more of the following types of bicomponent fibers: core / sheath fibers (e.g., concentric core / sheath fibers, non-concentric core-sheath fibers), segmented disc fibers, parallel fibers, tip-trefoil fibers, split fibers, and “island” fibers. Core-sheath bicomponent fibers can contain a sheath having a melting point lower than that of the core. When heated (e.g., during a bonding step), the sheath can melt before the core, thereby bonding the multicomponent fibers together while the core remains solid. In such embodiments, the multicomponent fibers can act as a binder for the fiber web and / or phase.

[0047] Non-limiting examples of suitable material pairs that can be included in bicomponent fibers include poly(ethylene) / poly(ester) (e.g., poly(ethylene) / poly(ethylene terephthalate)), poly(propylene) / poly(ester) (e.g., poly(propylene) / poly(ethylene terephthalate)), copoly(ester) / poly(ester) (e.g., copoly(ethylene terephthalate) / poly(ethylene terephthalate)), poly(butylene terephthalate) / poly(ethylene terephthalate), copoly(amide) / poly(amide), poly(amide) / poly(propylene), and poly(ethylene) / poly(propylene). In the foregoing list, materials with lower melting points are listed first, followed by materials with higher melting points. A core-sheath bicomponent fiber containing one of such pairs can have a sheath containing a first material and a core containing a second material. In one set of embodiments, the core-sheath bicomponent fiber can comprise a core containing a thermosetting polymer and a sheath containing a thermoplastic polymer.

[0048] The adhesives and multicomponent fibers described herein may contain components having a variety of suitable melting points. In some embodiments, the adhesive fibers and / or multicomponent fibers contain components having melting points of ≥70°C, ≥80°C, ≥90°C, ≥100°C, ≥110°C, ≥120°C, ≥130°C, ≥140°C, ≥150°C, ≥160°C, ≥170°C, ≥180°C, ≥190°C, ≥200°C, ≥210°C, ≥220°C, ≥250°C, ≥300°C, ≥250°C, ≥300°C, ≥350°C, or ≥400°C. In some embodiments, the adhesive fibers and / or multi-component fibers comprise components having the following melting points: less than or equal to 450°C, less than or equal to 400°C, less than or equal to 350°C, less than or equal to 300°C, less than or equal to 250°C, less than or equal to 220°C, less than or equal to 210°C, less than or equal to 200°C, less than or equal to 190°C, less than or equal to 180°C, less than or equal to 170°C, less than or equal to 160°C, less than or equal to 150°C, less than or equal to 140°C, less than or equal to 130°C, less than or equal to 120°C, less than or equal to 110°C, less than or equal to 100°C, less than or equal to 90°C, or less than or equal to 80°C. Combinations of the above ranges are also possible (e.g., greater than or equal to 70°C and less than or equal to 450°C, greater than or equal to 80°C and less than or equal to 450°C, greater than or equal to 80°C and less than or equal to 230°C, or greater than or equal to 110°C and less than or equal to 230°C). Other ranges are also possible. In some embodiments, the bonding fibers and / or multi-component fibers contain components with a melting point less than or equal to 100°C.

[0049] The melting points of the components in bonded fibers and multicomponent fibers can be determined by differential scanning calorimetry (DSC). A DSC measurement can be performed by heating the fiber to 500°C at 20°C / min, cooling the fiber to room temperature, and then reheating it to 500°C at 20°C / min to determine the melting point.

[0050] When adhesive fibers and / or multicomponent fibers contain two components, each component may independently have a melting point within one or more of the ranges described above. Adhesive fibers and multicomponent fibers containing two or more components may contain only components with the same melting point, only components with different melting points, or at least one pair of components with the same melting point and at least one pair of components with different melting points.

[0051] In some embodiments, the bonding fibers and / or multi-component fibers comprise two components with a melting point difference of the following: greater than or equal to 50°C, greater than or equal to 75°C, greater than or equal to 100°C, greater than or equal to 125°C, greater than or equal to 150°C, greater than or equal to 175°C, greater than or equal to 200°C, greater than or equal to 225°C, greater than or equal to 250°C, greater than or equal to 275°C, greater than or equal to 300°C, greater than or equal to 325°C, or greater than or equal to 350°C. In some embodiments, the bonding fibers and / or multi-component fibers comprise two components with a melting point difference of the following: less than or equal to 380°C, less than or equal to 350°C, less than or equal to 325°C, less than or equal to 300°C, less than or equal to 275°C, less than or equal to 250°C, less than or equal to 225°C, less than or equal to 200°C, less than or equal to 175°C, less than or equal to 150°C, less than or equal to 125°C, less than or equal to 100°C, or less than or equal to 75°C. Combinations of the above ranges are also possible (e.g., greater than or equal to 50°C and less than or equal to 75°C). Other ranges are also possible.

[0052] In some embodiments, the fiber web comprises fibrillated fibers. In such cases, the amount of fibrillated fibers present in the fiber web and / or phase can be selected as desired. The fibrillated fibers may account for greater than or equal to 0.1 wt%, greater than or equal to 0.2 wt%, greater than or equal to 0.5 wt%, greater than or equal to 0.75 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 5 wt%, greater than or equal to 7.5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, greater than or equal to 20 wt%, greater than or equal to 25 wt%, greater than or equal to 30 wt%, greater than or equal to 35 wt%, greater than or equal to 40 wt%, or greater than or equal to 45 wt%. The fibrillated fibers may comprise less than or equal to 50% by weight, less than or equal to 45% by weight, less than or equal to 40% by weight, less than or equal to 35% by weight, less than or equal to 30% by weight, less than or equal to 25% by weight, less than or equal to 20% by weight, less than or equal to 15% by weight, less than or equal to 10% by weight, less than or equal to 7.5% by weight, less than or equal to 5% by weight, less than or equal to 2% by weight, less than or equal to 1% by weight, less than or equal to 0.75% by weight, less than or equal to 0.5% by weight, or less than or equal to 0.2% by weight. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1% by weight and less than or equal to 50% by weight, greater than or equal to 0.5% by weight and less than or equal to 40% by weight, or greater than or equal to 1% by weight and less than or equal to 30% by weight). Other ranges are also possible.

[0053] When two or more types of fibrillated fibers are present in a fiber web and / or phase, the amount of each type of fibrillated fiber in the fiber web and / or phase may independently fall within one or more of the aforementioned ranges, and / or all fibrillated fibers may be present together in amounts within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing fibrillated fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0054] The fibrillated fibers present in the fiber web can have various suitable average diameters. In some embodiments, the average diameter of the fibrillated fibers present in the fiber web and / or phase is greater than or equal to 0.1 micrometers, greater than or equal to 0.15 micrometers, greater than or equal to 0.2 micrometers, greater than or equal to 0.3 micrometers, greater than or equal to 0.5 micrometers, greater than or equal to 0.75 micrometers, greater than or equal to 1 micrometer, greater than or equal to 2 micrometers, greater than or equal to 3 micrometers, greater than or equal to 5 micrometers, greater than or equal to 7.5 micrometers, greater than or equal to 10 micrometers, greater than or equal to 13 micrometers, greater than or equal to 15 micrometers, or greater than or equal to 17.5 micrometers. In some embodiments, the average diameter of the fibrillated fibers present in the fiber web and / or phase is less than or equal to 20 micrometers, less than or equal to 17.5 micrometers, less than or equal to 15 micrometers, less than or equal to 13 micrometers, less than or equal to 10 micrometers, less than or equal to 7.5 micrometers, less than or equal to 5 micrometers, less than or equal to 3 micrometers, less than or equal to 2 micrometers, less than or equal to 1 micrometer, less than or equal to 0.75 micrometers, less than or equal to 0.5 micrometers, less than or equal to 0.2 micrometers, or less than or equal to 0.15 micrometers. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1 micrometers and less than or equal to 20 micrometers, greater than or equal to 0.1 micrometers and less than or equal to 15 micrometers, or greater than or equal to 0.15 micrometers and less than or equal to 13 micrometers). Other ranges are also possible.

[0055] When two or more types of fibrillated fibers are present in a fiber web and / or phase, the average diameter of each type of fibrillated fiber may independently fall within one or more of the aforementioned ranges, and / or all fibrillated fibers may together have an average diameter within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing fibrillated fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0056] The fibrillated fibers present in the fiber web can have various suitable average lengths. In some embodiments, the average length of the fibrillated fibers present in the fiber web and / or phase is greater than or equal to 1 mm, greater than or equal to 1.25 mm, greater than or equal to 1.5 mm, greater than or equal to 1.75 mm, greater than or equal to 2 mm, greater than or equal to 2.5 mm, greater than or equal to 3 mm, greater than or equal to 3.5 mm, greater than or equal to 4 mm, greater than or equal to 4.5 mm, greater than or equal to 5 mm, or greater than or equal to 5.5 mm. In some embodiments, the average length of the fibrillated fibers present in the fiber web and / or phase is less than or equal to 6 mm, less than or equal to 5.5 mm, less than or equal to 5 mm, less than or equal to 4.5 mm, less than or equal to 4 mm, less than or equal to 3.5 mm, less than or equal to 3 mm, less than or equal to 2.5 mm, less than or equal to 2 mm, less than or equal to 1.75 mm, less than or equal to 1.5 mm, or less than or equal to 1.25 mm. Combinations of the above ranges are also possible (e.g., greater than or equal to 1 mm and less than or equal to 6 mm, greater than or equal to 1.5 mm and less than or equal to 5 mm, or greater than or equal to 2 mm and less than or equal to 4 mm). Other ranges are also possible.

[0057] When two or more types of fibrillated fibers are present in a fiber web and / or phase, the average length of each type of fibrillated fiber may independently fall within one or more of the aforementioned ranges, and / or all fibrillated fibers may together have an average length within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing fibrillated fibers are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0058] The fibrillated fibers present in the fiber web may have various suitable fibrillation levels. In some embodiments, the fibrillated fibers have a Canadian standard freeness value greater than or equal to 20 CSF, greater than or equal to 30 CSF, greater than or equal to 40 CSF, greater than or equal to 50 CSF, greater than or equal to 60 CSF, greater than or equal to 75 CSF, greater than or equal to 100 CSF, greater than or equal to 200 CSF, greater than or equal to 300 CSF, greater than or equal to 400 CSF, greater than or equal to 500 CSF, greater than or equal to 600 CSF, or greater than or equal to 700 CSF. In some implementations, the Canadian Standard Freeness (CSF) value of the fibrillated fibers is less than or equal to 850 CSF, less than or equal to 700 CSF, less than or equal to 600 CSF, less than or equal to 500 CSF, less than or equal to 400 CSF, less than or equal to 300 CSF, less than or equal to 200 CSF, less than or equal to 100 CSF, less than or equal to 75 CSF, less than or equal to 60 CSF, less than or equal to 50 CSF, less than or equal to 40 CSF, or less than or equal to 30 CSF. Combinations of the above ranges are also possible (e.g., greater than or equal to 20 CSF and less than or equal to 850 CSF, greater than or equal to 40 CSF and less than or equal to 700 CSF, or greater than or equal to 60 CSF and less than or equal to 500 CSF). Other ranges are also possible.

[0059] When two or more types of fibrillated fibers are present in a fiber web and / or phase, the Canadian standard freeness value for each type of fibrillated fiber may independently fall within one or more of the aforementioned ranges, and / or all fibrillated fibers may together have a Canadian standard freeness value within one or more of the aforementioned ranges. When two or more fiber webs and / or phases containing fibrillated fibers are present, the foregoing sentence may apply independently to each such fiber web and / or phase.

[0060] The Canadian Standard Freeness (CSF) of fibrillated fibers can be measured according to the Canadian Standard Freeness Test specified by TAPPI Test Method T-227-om-09 for pulp freeness. This test provides an average CSF value.

[0061] Various suitable types of fibrillated fibers can be included in the fiber webs described herein. Fibrillated fibers may include a parent fiber branching into fibrils of smaller diameter, which in some cases may further branch into fibrils of even smaller diameters, where further branching is also possible. The branching nature of the fibrils can increase the surface area of ​​the fiber web in which fibrillated fibers are used, and can increase the number of contact points between the fibrillated fibers and other fibers in the fiber web. Such an increase in contact points between the fibrillated fibers and other fibers in the fiber web can improve one or more mechanical properties of the fiber web (e.g., flexibility, strength, filtration efficiency). Fibrillated fibers may be microfibrillated (e.g., which may include fibrils with diameters on the order of micrometers) and / or nanofibrillated (e.g., which may include fibrils with submicrometer diameters). Fibrillated fibers may also lack a parent fiber. Non-limiting examples of fibrillated fiber types that may be included in the fiber webs described herein include lyocell fibers, nanocellulose, and / or microfibrillated cellulose.

[0062] In some embodiments, the fiber web comprises resin. In such cases, the amount of resin present in the fiber web and / or phase can be selected as desired. The resin may account for greater than or equal to 0.1 wt%, greater than or equal to 0.2 wt%, greater than or equal to 0.5 wt%, greater than or equal to 0.75 wt%, greater than or equal to 1 wt%, greater than or equal to 2 wt%, greater than or equal to 5 wt%, greater than or equal to 7.5 wt%, greater than or equal to 10 wt%, greater than or equal to 15 wt%, greater than or equal to 20 wt%, greater than or equal to 25 wt%, greater than or equal to 30 wt%, or greater than or equal to 35 wt%. The resin may comprise less than or equal to 40% by weight, less than or equal to 35% by weight, less than or equal to 30% by weight, less than or equal to 25% by weight, less than or equal to 20% by weight, less than or equal to 15% by weight, less than or equal to 10% by weight, less than or equal to 7.5% by weight, less than or equal to 5% by weight, less than or equal to 2% by weight, less than or equal to 1% by weight, less than or equal to 0.75% by weight, less than or equal to 0.5% by weight, or less than or equal to 0.2% by weight. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1% by weight and less than or equal to 40% by weight, greater than or equal to 0.5% by weight and less than or equal to 30% by weight, or greater than or equal to 1% by weight and less than or equal to 25% by weight). Other ranges are also possible.

[0063] When two or more types of resin are present in the fiber web and / or phase, the amount of each type of resin present in the fiber web and / or phase may independently be within one or more of the above-mentioned ranges, and / or all resins may be present together in amounts within one or more of the above-mentioned ranges. When two or more resin-containing fiber webs and / or phases are present, the foregoing sentences may apply independently to each such fiber web and / or phase.

[0064] In some embodiments, the resin present in the fiber web can be oleophilic. In some embodiments, this can make the fiber web in which the resin is disposed oleophilic. For example, the resin present in the fiber web can be sufficiently oleophilic such that the fiber web and / or phase in which the resin is disposed has a relatively low oil grade. As an example, in some embodiments, the fiber web and / or phase containing the oleophilic resin has an oil grade of exactly 0. In some embodiments, the oil grade of the fiber web and / or phase containing the oleophilic resin is less than or equal to 1 (and greater than or equal to 0). In some embodiments, the fiber web and / or phase containing the oleophilic resin is so oleophilic that it cannot be accurately measured by determining the oil grade. For example, droplets with a surface tension higher than Kaydol, formed according to the steps of AATCC TM118 (1997) described below, placed on the fiber web and / or phase containing the oleophilic resin in the manner described in those steps, and analyzed by the steps described below, can wet the surface of the fiber web and / or phase as described in the steps described below.

[0065] When there are two or more fiber webs and / or phases containing oleophilic resins, each fiber web and / or phase may independently have the oleophilicity and / or oiliness grades as described in the preceding paragraphs.

[0066] Oil grades can be determined according to AATCC TM 118 (1997) at 23°C and 50% relative humidity (RH). In short, five droplets (average droplet diameter approximately 2 mm) of each test oil are placed at five different locations on the surface of the fiber web and / or phase. The test oil with the highest surface tension (e.g., a contact angle greater than or equal to 90°) that does not wet the surface of the fiber web and / or phase after 30 seconds of contact at 23°C and 50% RH corresponds to the oil grade (listed in Table 1). For example, if a test oil with a surface tension of 26.6 mN / m does not wet (i.e., a contact angle greater than or equal to 90°) the surface of the fiber web and / or phase after 30 seconds, but a test oil with a surface tension of 25.4 mN / m wets the surface of the fiber web and / or phase within 30 seconds, then the oil grade for the fiber web and / or phase is 4. As another example, if a test oil with a surface tension of 25.4 mN / m fails to wet the surface of the fiber web and / or phase after 30 seconds, but a test oil with a surface tension of 23.8 mN / m wets the surface of the fiber web and / or phase within 30 seconds, then the oil grade for the fiber web and / or phase is 5. As yet another example, if a test oil with a surface tension of 23.8 mN / m fails to wet the surface of the fiber web and / or phase after 30 seconds, but a test oil with a surface tension of 21.6 mN / m wets the surface of the fiber web and / or phase within 30 seconds, then the oil grade for the fiber web and / or phase is 6. In some embodiments, if, in a given test, three or more of five droplets partially wet the surface (e.g., droplets form on the surface, but are not perfectly round), the oil grade is expressed as the nearest 0.5 value determined by subtracting 0.5 from the number of test liquids. For example, if a test oil with a surface tension of 25.4 mN / m fails to wet the surface of the fiber web and / or phase after 30 seconds, but a test oil with a surface tension of 23.8 mN / m only partially wets the surface of the fiber web and / or phase within 30 seconds (e.g., three or more test droplets form non-circular droplets on the surface of the fiber web and / or phase), then the oil grade for the fiber web and / or phase is 5.5. If all test oils listed in Table 1 below wet the surface of the fiber web and / or phase after 30 seconds, then the oil grade for the fiber web and / or phase is 0.

[0067] Table 1.

[0068]

[0069] The resin present in the fiber web can be hydrophilic or hydrophobic (e.g., except that it is oleophilic).

[0070] The resin present in the fiber web can be hydrophilic or hydrophobic (e.g., except for being oleophilic). In some embodiments, the water-repellent class number of the fiber web and / or phase containing the resin is greater than or equal to 0, greater than or equal to 1, greater than or equal to 2, greater than or equal to 3, greater than or equal to 4, greater than or equal to 5, greater than or equal to 6, or greater than or equal to 7. In some embodiments, the water-repellent class number of the fiber web and / or phase containing the resin is less than or equal to 8, less than or equal to 7, less than or equal to 6, less than or equal to 5, less than or equal to 4, less than or equal to 3, less than or equal to 2, or less than or equal to 1. Combinations of the above ranges are also possible (e.g., greater than or equal to 0 and less than or equal to 8). Other ranges are also possible.

[0071] When there are two or more resin-containing fiber webs and / or phases, each fiber web and / or phase may independently have a number of water-repellent grades within one or more of the above ranges.

[0072] The water repellency rating of the fiber web and / or phase can be determined according to AATCC 193 TM 193 (2005). In short, a similar procedure to that described above for determining the oil rating of the fiber web and / or phase can be performed, except that: (1) three droplets are used for each test liquid; (2) each droplet is allowed to contact the fiber web and / or phase for ten seconds; (3) the contact is performed at 21°C and 65% RH; and (4) the test liquids and their corresponding water repellency ratings are provided below in Table 2. Similar to the procedure for determining the oil rating, the water repellency rating of the fiber web and / or phase corresponds to the test liquid with the maximum surface tension, which does not wet the surface of the fiber web and / or phase after the relevant contact step (e.g., a contact angle with the surface greater than or equal to 90°). If all the test liquids listed in Table 2 below wet the surface of the fiber web and / or phase after 10 seconds, the water repellency rating of the fiber web and / or phase is 0.

[0073] Table 2.

[0074]

[0075] Resins suitable for inclusion in the fiber webs described herein can have a variety of suitable chemical compositions. Non-limiting examples of resin types that may be included in the fiber webs described herein include resins containing thermoplastic polymers (e.g., acrylics, polyvinyl acetate, polyesters, polyamides, polycarboxylic acids, nylon, etc.), resins containing thermosetting polymers (e.g., epoxy resins, phenolic resins, melamine, etc.), and combinations thereof. In some embodiments, the resin includes one or more of vinyl acetate resins and polyvinyl alcohol resins. In some embodiments, the fiber web comprises acrylic resins.

[0076] In some embodiments, the fiber web, phase, and / or filter media described herein contain relatively small amounts of fluorinated substances (e.g., molecules containing one or more fluorine atoms, government-regulated fluorinated substances, toxic fluorinated substances, PFAS). In such embodiments, the fluorinated substance may constitute less than or equal to 10% by weight, less than or equal to 7.5% by weight, less than or equal to 5% by weight, less than or equal to 2.5% by weight, less than or equal to 1% by weight, less than or equal to 0.75% by weight, less than or equal to 0.5% by weight, less than or equal to 0.2% by weight, or less than or equal to 0.1% by weight. In such embodiments, the fluorinated substance may constitute greater than or equal to 0% by weight, greater than or equal to 0.1% by weight, greater than or equal to 0.2% by weight, greater than or equal to 0.5% by weight, greater than or equal to 0.75% by weight, greater than or equal to 1% by weight, greater than or equal to 2.5% by weight, greater than or equal to 5% by weight, or greater than or equal to 7.5% by weight. Combinations of the above ranges are also possible (e.g., less than or equal to 10% by weight and greater than or equal to 0% by weight). In some embodiments, the fluorinated material comprises exactly 0% by weight of the fiber web, phase, and / or filter media.

[0077] In some embodiments, the total fluoride content of the fiber web, phase, or filter media is within one or more of the above-mentioned ranges. In some embodiments, the total PFAS content of the fiber web, phase, or filter media is within one or more of the above-mentioned ranges. When two or more fiber webs and / or phases are present in the filter media, the foregoing two sentences may apply independently to each such fiber web and / or phase.

[0078] The fiber webs and their phases described herein can have a variety of suitable weights per unit area. In some embodiments, the weight per unit area of ​​the fiber webs and / or phases is greater than or equal to 130 gsm, greater than or equal to 140 gsm, greater than or equal to 150 gsm, greater than or equal to 175 gsm, greater than or equal to 200 gsm, greater than or equal to 225 gsm, greater than or equal to 250 gsm, greater than or equal to 275 gsm, greater than or equal to 300 gsm, greater than or equal to 325 gsm, greater than or equal to 350 gsm, or greater than or equal to 380 gsm. In some embodiments, the area weight of the fiber web and / or phase is less than or equal to 400 gsm, less than or equal to 380 gsm, less than or equal to 350 gsm, less than or equal to 325 gsm, less than or equal to 300 gsm, less than or equal to 275 gsm, less than or equal to 250 gsm, less than or equal to 225 gsm, less than or equal to 200 gsm, less than or equal to 175 gsm, less than or equal to 150 gsm, or less than or equal to 140 gsm. Combinations of the above ranges are also possible (e.g., greater than or equal to 130 gsm and less than or equal to 400 gsm, greater than or equal to 140 gsm and less than or equal to 380 gsm, or greater than or equal to 150 gsm and less than or equal to 350 gsm). Other ranges are also possible.

[0079] When the filter media comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have a unit area weight within one or more of the above ranges.

[0080] The weight per unit area of ​​a fiber web or phase can be measured according to ISO 536:2012.

[0081] Some of the fiber webs and / or their phases described herein have relatively high coalescence γ values. In some embodiments, the coalescence γ value of the fiber web and / or phase is less than or equal to 35, less than or equal to 30, less than or equal to 25, less than or equal to 20, less than or equal to 15, less than or equal to 10, less than or equal to 7.5, less than or equal to 5, or less than or equal to 2. In some embodiments, the coalescence γ value of the fiber web and / or phase is greater than or equal to 1, greater than or equal to 2, greater than or equal to 5, greater than or equal to 7.5, greater than or equal to 10, greater than or equal to 15, greater than or equal to 20, greater than or equal to 25, or greater than or equal to 30. Combinations of the above ranges are also possible (e.g., less than or equal to 35 and greater than or equal to 1, or less than or equal to 30 and greater than or equal to 5). Other ranges are also possible.

[0082] When the filter medium comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have a coalescence γ value within one or more of the above ranges.

[0083] The coalescence γ value of the fiber web or phase can be determined by evaluating the following equation:

[0084]

[0085] in Let be the saturation pressure drop, and be the efficiency for the mineral oil droplets described below.

[0086] The saturation pressure drop and efficiency can be determined by the following steps: exposing a fiber web or phase to mineral oil droplets, and then measuring the pressure drop and efficiency after the fiber web or phase is saturated with mineral oil. This measurement can be performed while the fiber web or phase has a flat sheet geometry. Exposure may include generating mineral oil droplets using an aerosol generator, suspending these droplets in the air, and then blowing them towards the fiber web or phase at a distance of 100 cm. 2 Partial. The kinematic viscosity of mineral oil can be 46 mm. 2 The mineral oil droplets can be polydisperse, with an average diameter of less than 1 micrometer and greater than 0.1 micrometers. When impacted onto a fiber web or phase, air containing suspended mineral oil droplets can travel at a surface velocity of 20 cm / s under atmospheric pressure. Its concentration in air can be 2.5 g / m³. 3 During this process, pressure drop can be measured using pressure sensors upstream and downstream of the fiber web and / or phase. The concentration of mineral oil particles downstream of the fiber web and / or phase can be measured using scattered light spectroscopy.

[0087] When this step is performed, the saturation of the fiber web and / or phase is assessed by measuring the stability of the pressure drop of the fiber web and / or phase. Saturation is achieved after the pressure drop has stabilized (i.e., reached equilibrium) for 30 minutes. The efficiency is the average efficiency calculated over the 30-minute stabilization period, and the saturation pressure drop is the average pressure drop calculated over the 30-minute stabilization period.

[0088] When subjected to the processes described above for measuring efficiency and pressure drop, some of the fiber webs and phases described herein allow a relatively small number of target mineral oil droplets to pass through them. In some embodiments, during the time period for measuring saturated pressure drop and efficiency, the average concentration of mineral oil droplets downstream of the fiber web and / or phase is less than or equal to 1,000,000 drops / cm³. 3 Less than or equal to 900,000 drops / cm 3 Less than or equal to 800,000 drops / cm 3 Less than or equal to 500,000 drops / cm 3Less than or equal to 200,000 drops / cm 3 Less than or equal to 100,000 drops / cm 3 Less than or equal to 75,000 drops / cm 3 Less than or equal to 50,000 drops / cm 3 Less than or equal to 20,000 drops / cm 3 Less than or equal to 10,000 drops / cm 3 ≤7,500 drops / cm 3 Less than or equal to 5,000 drops / cm 3 Less than or equal to 2,000 drops / cm 3 Less than or equal to 1,000 drops / cm 3 Less than or equal to 750 drops / cm 3 Less than or equal to 500 drops / cm 3 Less than or equal to 200 drops / cm 3 Less than or equal to 100 drops / cm 3 Less than or equal to 75 drops / cm 3 Less than or equal to 50 drops / cm 3 Or less than or equal to 20 drops / cm 3 In some implementations, during the time period for measuring saturation pressure drop and efficiency, the average concentration of mineral oil droplets downstream of the fiber web and / or phase is greater than or equal to 10 drops / cm². 3 ≥20 drops / cm 3 ≥50 drops / cm 3 ≥75 drops / cm 3 ≥100 drops / cm 3 ≥200 drops / cm 3 ≥500 drops / cm 3 ≥750 drops / cm 3 ≥1,000 drops / cm 3 ≥2,000 drops / cm 3 ≥5,000 drops / cm 3 ≥7,500 drops / cm 3 ≥10,000 drops / cm 3 ≥20,000 drops / cm 3 ≥50,000 drops / cm 3 ≥75,000 drops / cm 3 ≥100,000 drops / cm 3 ≥200,000 drops / cm3 ≥500,000 drops / cm 3 ≥800,000 drops / cm 3 Or greater than or equal to 900,000 drops / cm 3 Combinations of the above ranges are also possible (e.g., less than or equal to 1,000,000 drops / cm). 3 And greater than or equal to 10 drops / cm 3 Other ranges are also possible.

[0089] When the filter media comprises two or more fiber webs and / or phases, during the time period for measuring saturation pressure drop and efficiency, each fiber web and / or phase may independently have an average concentration of mineral oil droplets downstream of one or more of the fiber webs and / or phases within the ranges described above.

[0090] In some embodiments, the fiber web and / or phase has a relatively favorable pore size distribution. In such cases, the fiber web and / or phase may have a relatively low number and / or percentage of pores with a diameter less than 1.25 micrometers. In some embodiments, less than 30%, less than or equal to 25%, less than or equal to 20%, less than or equal to 15%, less than or equal to 10%, or less than or equal to 7.5% of the pores in the fiber web and / or phase have a diameter less than 1.25 micrometers. In some embodiments, greater than or equal to 5%, greater than or equal to 7.5%, greater than or equal to 10%, greater than or equal to 15%, greater than or equal to 20%, or greater than or equal to 25% of the pores in the fiber web and / or phase have a diameter less than or equal to 1.25 micrometers. Combinations of the above ranges are also possible (e.g., less than or equal to 30% and greater than or equal to 5%). Other ranges are also possible.

[0091] When the filter media comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have a number and / or percentage of pores with a diameter of less than 1.25 micrometers within one or more of the ranges described above.

[0092] The number and / or percentage of pores with a diameter less than 1.25 micrometers can be measured according to ASTM F316 (2003).

[0093] In some embodiments, the fiber web and / or phase may have a relatively high number and / or percentage of pores with a diameter greater than or equal to 1.25 micrometers and less than or equal to 2.5 micrometers. In some embodiments, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, or 90% or more of the pores in the fiber web and / or phase have a diameter greater than or equal to 1.25 micrometers and less than or equal to 2.5 micrometers. In some embodiments, 95% or more, 90% or more, 85% or more, 80% or more, 75% or more, 70% or more, 65% or more, 60% or more, 55% or more, 50% or more, or 45% or more of the pores in the fiber web and / or phase have a diameter greater than or equal to 1.25 micrometers and less than or equal to 2.5 micrometers. Combinations of the above ranges are also possible (e.g., greater than or equal to 40% and less than or equal to 95%). Other ranges are also possible.

[0094] When the filter media comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have a number and / or percentage of pores with a diameter greater than or equal to 1.25 micrometers and less than or equal to 2.5 micrometers, within one or more of the ranges described above.

[0095] The number and / or percentage of holes with a diameter greater than or equal to 1.25 micrometers and less than or equal to 2.5 micrometers can be measured according to ASTM F316 (2003).

[0096] In some embodiments, the ratio of the number of pores with a diameter less than 1.25 micrometers to the number of pores with a diameter greater than or equal to 1.25 micrometers and less than or equal to 2.5 micrometers may be relatively low. In some embodiments, this ratio is less than or equal to 1, less than or equal to 0.95, less than or equal to 0.9, less than or equal to 0.85, less than or equal to 0.8, less than or equal to 0.75, less than or equal to 0.7, less than or equal to 0.65, less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, less than or equal to 0.45, less than or equal to 0.4, less than or equal to 0.35, less than or equal to 0.3, less than or equal to 0.25, less than or equal to 0.2, or less than or equal to 0.15. In some implementations, the ratio is greater than or equal to 0.1, greater than or equal to 0.15, greater than or equal to 0.2, greater than or equal to 0.25, greater than or equal to 0.3, greater than or equal to 0.35, greater than or equal to 0.4, greater than or equal to 0.45, greater than or equal to 0.5, greater than or equal to 0.55, greater than or equal to 0.6, greater than or equal to 0.65, greater than or equal to 0.7, greater than or equal to 0.75, greater than or equal to 0.8, greater than or equal to 0.85, greater than or equal to 0.9, or greater than or equal to 0.95. Combinations of the above ranges are also possible (e.g., less than or equal to 1 and greater than or equal to 0.1). Other ranges are also possible.

[0097] When the filter medium comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have a ratio of the number of pores with a diameter less than 1.25 micrometers to the number of pores with a diameter greater than or equal to 1.25 micrometers and less than or equal to 2.5 micrometers, within one or more of the above ranges.

[0098] The fiber web described herein can have a variety of suitable average flow apertures. In some embodiments, the average flow aperture of the fiber web and / or its phase is greater than or equal to 0.5 micrometers, greater than or equal to 0.75 micrometers, greater than or equal to 1 micrometer, greater than or equal to 2 micrometers, greater than or equal to 5 micrometers, greater than or equal to 7.5 micrometers, greater than or equal to 10 micrometers, greater than or equal to 12.5 micrometers, greater than or equal to 15 micrometers, greater than or equal to 17.5 micrometers, greater than or equal to 20 micrometers, or greater than or equal to 22.5 micrometers. In some embodiments, the average flow aperture of the fiber web and / or its phase is less than or equal to 25 micrometers, less than or equal to 22.5 micrometers, less than or equal to 20 micrometers, less than or equal to 17.5 micrometers, less than or equal to 15 micrometers, less than or equal to 12.5 micrometers, less than or equal to 10 micrometers, less than or equal to 7.5 micrometers, less than or equal to 5 micrometers, less than or equal to 2 micrometers, less than or equal to 1 micrometer, or less than or equal to 0.75 micrometers. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.5 micrometers and less than or equal to 25 micrometers, greater than or equal to 0.5 micrometers and less than or equal to 20 micrometers, or greater than or equal to 0.5 micrometers and less than or equal to 15 micrometers). Other ranges are also possible.

[0099] When the filter medium comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have an average flow orifice diameter within one or more of the above ranges.

[0100] The average flow orifice diameter of the fiber web or phase can be measured according to ASTM F316 (2003).

[0101] The fiber web described herein can have various suitable thicknesses. In some embodiments, the thickness of the fiber web and / or its phase is greater than or equal to 0.1 mm, greater than or equal to 0.2 mm, greater than or equal to 0.3 mm, greater than or equal to 0.5 mm, greater than or equal to 0.75 mm, greater than or equal to 1 mm, greater than or equal to 1.5 mm, greater than or equal to 2 mm, greater than or equal to 2.5 mm, greater than or equal to 3 mm, greater than or equal to 3.5 mm, greater than or equal to 4 mm, or greater than or equal to 4.5 mm. In some embodiments, the thickness of the fiber web and / or its phase is less than or equal to 5 mm, less than or equal to 4.5 mm, less than or equal to 4 mm, less than or equal to 3.5 mm, less than or equal to 3 mm, less than or equal to 2.5 mm, less than or equal to 2 mm, less than or equal to 1.5 mm, less than or equal to 1 mm, less than or equal to 0.75 mm, less than or equal to 0.5 mm, less than or equal to 0.3 mm, or less than or equal to 0.2 mm. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1 mm and less than or equal to 5 mm, greater than or equal to 0.2 mm and less than or equal to 4.5 mm, or greater than or equal to 0.3 mm and less than or equal to 4 mm). Other ranges are also possible.

[0102] When the filter medium comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have a thickness within one or more of the above ranges.

[0103] The thickness of the fiber web or phase can be 1 N / cm. 2 The pressure applied is measured according to ISO 534 (2012).

[0104] The fiber web described herein can have a variety of suitable air permeability. In some embodiments, the air permeability of the fiber web and / or phase is greater than or equal to 5 L / (m²). 2 • seconds), greater than or equal to 7 L / (m 2 • seconds), greater than or equal to 10 L / (m 2 • seconds), greater than or equal to 20 L / (m 2 • seconds), greater than or equal to 50 L / (m 2 • seconds), greater than or equal to 75 L / (m 2 • seconds), greater than or equal to 100 L / (m 2 • seconds), greater than or equal to 150 L / (m 2 • seconds), greater than or equal to 200 L / (m 2 • seconds), greater than or equal to 250 L / (m 2 • seconds), greater than or equal to 300 L / (m2 · seconds), greater than or equal to 350 L / (m 2 • seconds), or greater than or equal to 380 L / (m 2 • seconds). In some embodiments, the air permeability of the fiber web and / or phase is less than or equal to 400 L / (m²). 2 • seconds), less than or equal to 380 L / (m 2 • seconds), less than or equal to 350 L / (m 2 • seconds), less than or equal to 300 L / (m 2 • seconds), less than or equal to 250 L / (m 2 • seconds), less than or equal to 20 L / (m 2 • seconds), less than or equal to 150 L / (m 2 • seconds), less than or equal to 100 L / (m 2 • seconds), less than or equal to 75 L / (m 2 • seconds), less than or equal to 50 L / (m 2 • seconds), less than or equal to 20 L / (m 2 • seconds), less than or equal to 10 L / (m 2 • seconds), or less than or equal to 7 L / (m 2 • seconds). Combinations of the above ranges are also possible (e.g., greater than or equal to 5 L / (m 2 • seconds) and less than or equal to 400 L / (m 2 • seconds), greater than or equal to 7 L / (m 2 • seconds) and less than or equal to 380 L / (m 2 • seconds), or greater than or equal to 10 L / (m 2 · seconds) and less than or equal to 350 L / (m 2 (·seconds). Other ranges are also possible.

[0105] When the filter media comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have an air permeability within one or more of the above ranges.

[0106] The air permeability of the fiber web and / or phase can be measured at a pressure of 200 Pa according to EN / ISO 9237 (1995).

[0107] The fiber web described herein can have a variety of suitable pore permeability indices. In some embodiments, the pore permeability indices of the fiber web and / or phase are greater than or equal to 0.1, greater than or equal to 0.2, greater than or equal to 0.5, greater than or equal to 0.75, greater than or equal to 1, or greater than or equal to 1.25. In some embodiments, the pore permeability indices of the fiber web and / or phase are less than or equal to 1.5, less than or equal to 1, less than or equal to 0.75, less than or equal to 0.5, or less than or equal to 0.2. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1 and less than or equal to 1.5). Other ranges are also possible.

[0108] When the filter medium comprises two or more fiber webs and / or phases, each fiber web and / or phase may independently have a pore permeability index within one or more of the above ranges.

[0109] The pore permeability index of the fiber web and / or phase can be calculated by evaluating the following equation:

[0110]

[0111] The thickness of the filter media, including the fiber web described herein, can be selected as desired. In some embodiments, the thickness of the filter media is greater than or equal to 0.1 mm, greater than or equal to 0.2 mm, greater than or equal to 0.3 mm, greater than or equal to 0.5 mm, greater than or equal to 0.75 mm, greater than or equal to 1 mm, greater than or equal to 2 mm, greater than or equal to 5 mm, greater than or equal to 7.5 mm, greater than or equal to 10 mm, greater than or equal to 12.5 mm, greater than or equal to 15 mm, or greater than or equal to 17.5 mm. In some embodiments, the thickness of the filter media is less than or equal to 20 mm, less than or equal to 17.5 mm, less than or equal to 15 mm, less than or equal to 12.5 mm, less than or equal to 10 mm, less than or equal to 7.5 mm, less than or equal to 5 mm, less than or equal to 2 mm, less than or equal to 1 mm, less than or equal to 1 mm, less than or equal to 0.75 mm, less than or equal to 0.5 mm, or less than or equal to 0.2 mm. Combinations of the above ranges are also possible (e.g., greater than or equal to 0.1 mm and less than or equal to 20 mm). Other ranges are also possible.

[0112] The thickness of the filter media can be specified according to ISO 534 (2012) at 1 N / cm. 2 Measurements were taken under applied pressure.

[0113] The air permeability of the filter media, including the fiber webs described herein, can be selected as desired. In some embodiments, the air permeability of the filter media is within one or more of the ranges described elsewhere herein for the air permeability of the fiber webs.

[0114] The air permeability of the filter media can be measured at a pressure of 200 Pa according to EN / ISO 9237 (1995).

[0115] As described above, in some embodiments, the fiber web (and any phase therein) is manufactured by a wet web-forming process. Typically, a wet web-forming process involves blending one or more types of fibers together; for example, multiple glass fibers may be blended individually or with multiple fibrillated fibers and / or multiple bonded fibers to provide a fiber slurry. The slurry may be, for example, a water-based slurry. In some embodiments, the fibers are optionally stored individually or in combination in various storage tanks prior to blending.

[0116] In some embodiments, the individual fibers can be mixed and pulped together in separate containers. As an example, multiple glass fibers can be mixed and pulped together in one container, multiple fibrillated fibers can be mixed and pulped in a second container, and multiple bonded fibers can be mixed and pulped in a third container. Subsequently, the multiple fibers can be combined together to form a fiber mixture. The mixture can be processed by a pulper before and / or after the appropriate fibers are mixed together. In some embodiments, the mixture is processed by a pulper and / or storage tank before the fiber combination is mixed together. It is understood that other components (e.g., resins) can also be introduced into the mixture. Furthermore, it should be understood that other combinations of fiber types (e.g., the fiber types described herein) can be used in the fiber mixture.

[0117] Wet web forming processes may include applying a dispersion (e.g., pulp) or slurry of a solvent (e.g., an aqueous solvent such as water) onto a web conveyor belt in a paper machine (e.g., a fourdrinier or rotoformer) to form a single fiber web supported by the conveyor belt. During this process, a vacuum may be continuously applied to the fiber dispersion to remove the solvent from the fibers, thereby obtaining an article comprising a single fiber web.

[0118] In some implementations, multiple fiber webs can be formed simultaneously or sequentially in a wet web-forming process. For example, a fiber web can be formed as described above, and then one or more fiber webs can be formed on that fiber web by following the same steps. As an example, a dispersion or slurry in a solvent can be applied to a first fiber web on a web conveyor belt, and a vacuum can be applied to the dispersion or slurry to form a second fiber web on the first fiber web. Additional fiber webs can be formed on the first and second fiber webs by following the same process.

[0119] Any suitable method for producing the fiber pulp can be used. In some embodiments, additional additives are added to the pulp to facilitate processing. The temperature can also be adjusted to a suitable range, such as 33℉ to 100℉ (e.g., 50℉ to 85℉). In some cases, the temperature of the pulp is maintained. In some cases, the temperature is not actively regulated.

[0120] In some implementations, the wet web forming process uses equipment similar to that in conventional papermaking processes, such as hydraulks, forming machines or headboxes, dryers, and / or optional converters. In some cases, the web can also be made using laboratory papermaking molds. As discussed above, the pulp can be prepared in one or more pulpers. After the pulp is properly mixed in the pulper, it can be pumped to a headbox, where it may or may not be combined with other pulps. Additional additives may or may not be added. The pulp can also be diluted with additional water to achieve a final fiber concentration within a suitable range, for example, about 0.1% to 0.5% by weight.

[0121] In some cases, the pH of the pulp can be adjusted as desired. For example, the fibers in the pulp can be dispersed under acidic or neutral conditions.

[0122] Before feeding the pulp to the headbox, the pulp may optionally be passed through a centrifugal purifier and / or pressure screen to remove unwanted material (e.g., unfiberized material). The pulp may be passed through additional equipment (e.g., a refining machine or a defibrillator) to further improve fiber dispersion, or the pulp may not be passed through additional equipment (e.g., a refining machine or a defibrillator) to further improve fiber dispersion. For example, a defibrillator can be used to smooth or remove lumps or protrusions that may appear at any point during fiber pulp formation. The fibers can then be collected onto the screen or web at an appropriate rate using any suitable equipment (e.g., a fourdrinier paper machine, a cylinder forming machine, or an inclined fourdrinier paper machine).

[0123] In some embodiments, the fiber web (and any phase therein) is manufactured by a foaming process (e.g., the process described in U.S. Patent Application No. 18 / 326,932, which is incorporated herein by reference in its entirety for all purposes). In some embodiments, foaming involves adding one or more foaming additives (e.g., one or more surfactants, air) to a fiber dispersion to form a foam slurry comprising the fiber dispersion. The foam slurry may have any of a variety of suitable liquid fractions and / or foam densities that provide sufficient spacing between the fibers in the foam slurry, wherein the spacing between the fibers is occupied by liquid and / or gas (e.g., one or more air bubbles) in the foam slurry. The foam slurry is applied to a carrier and dried to provide a fiber web for use as a filter medium.

[0124] Figures 3 to 4 A schematic diagram of foam web formation according to some implementation schemes is shown. (Refer to...) Figure 3 Foam web formation may include providing a fiber dispersion 306. In some embodiments, the fiber dispersion 306 comprises fibers dispersed in a liquid. In some embodiments, the liquid comprises water. In some embodiments, providing the fiber dispersion 306 includes forming the fiber dispersion 306 in a pulper.

[0125] According to some implementation schemes, foam web formation involves adding one or more foaming additives to the fiber dispersion. For example, see reference... Figure 3 The method shown includes adding one or more foaming additives 308 to the fiber dispersion 306. In some embodiments, adding one or more foaming additives to the fiber dispersion provides a foam slurry in which the fibers are relatively uniformly dispersed (e.g., uniformly distributed) throughout the foam slurry.

[0126] In some embodiments, one or more foaming additives comprising surfactants are used. When present, the surfactants can advantageously reduce the surface tension of the liquid (e.g., water) in which the surfactant is present in the fibrous dispersion. Any of a variety of suitable surfactants can be used. In some embodiments, for example, the surfactants include amine oxides, ethoxylates, alkyl sulfates / salts, alkyl esters, ethanolamine, isotrigine ethoxylate, polyesters, polyacrylates, polysiloxanes, alkyl phosphates / salts, sodium lauryl sulfate, polyvinyl alcohol, stearylamine, and / or combinations thereof.

[0127] In some embodiments, one or more gas-containing foaming additives are used. When present, in some embodiments, the gas includes air (e.g., atmospheric air). When present, according to some embodiments, the gas (e.g., air) may be used in combination with one or more surfactants.

[0128] In some implementations, one or more foaming additives may be added to the fiber dispersion in the pulper. Prior to adding one or more foaming additives, the fiber dispersion may be transferred (e.g., flowed) from the pulper to a foam molding machine.

[0129] In some embodiments, foam web formation includes adding one or more resins to the fiber dispersion. For example, see reference... Figure 3 Foaming can include adding one or more resins 310 to the fiber dispersion 306.

[0130] In some implementations, one or more binders may be added to the fiber dispersion in the pulper. Prior to adding one or more binders, the fiber dispersion may also be transferred (e.g., flowed) from the pulper to a foam molding machine.

[0131] In some embodiments, foam web formation includes shaping a foam slurry containing a fiber dispersion. In some embodiments, the foam slurry can be formed as a result of adding one or more foaming additives (e.g., one or more surfactants and / or air) to the fiber dispersion. For example, see reference... Figure 3 The method includes forming a foam slurry 312 as a result of adding one or more foaming additives 308 to a fiber dispersion 306.

[0132] In some embodiments, the foam slurry can be formed in a foam molding machine. For example, in some embodiments, the fiber dispersion can be transferred (e.g., flowed) from a pulper to a foam molding machine before one or more foaming additives are added to the fiber dispersion.

[0133] Foam molding machines can include any of a variety of suitable fluid connections. For example, in some embodiments, a foam molding machine includes one or more fluid connections configured to transfer (e.g., flow) a fiber dispersion from a pulper to the foam molding machine. In some embodiments, one or more fluid connections configured to transfer the fiber dispersion from a pulper to the foam molding machine can be configured to control the flow rate of the fiber dispersion. In some embodiments, a foam molding machine can include one or more fluid connections configured to add one or more foaming additives and / or one or more binders to the fiber dispersion. In some embodiments, one or more fluid connections configured to add one or more foaming additives and / or one or more binders to the fiber dispersion can be configured to control the flow rate of one or more foaming additives and / or one or more binders.

[0134] In some implementations, the foam molding machine may include one or more temperature regulators for adjusting the temperature of the foam slurry in the foam molding machine.

[0135] In some implementations, the foam molding machine may include one or more pressure regulators for adjusting the pressure of the foam slurry in the foam molding machine.

[0136] According to some implementation schemes, foam web formation involves applying a foam slurry onto a carrier. For example, see reference... Figure 4 Foam web formation may include applying foam slurry 412 onto a carrier 414. In some embodiments, the carrier 414 is a semi-continuous or continuously moving carrier. According to some embodiments, the carrier 414 is planar. In some embodiments, for example, the foam slurry 412 is applied to the planar carrier 414 such that the foam slurry 412 has a two-dimensional planar structure.

[0137] Any of a variety of suitable carriers can be used. In some implementations, for example, carrier 414 can be a net.

[0138] In some embodiments, applying the foam slurry to a carrier (e.g., a semi-continuous or continuously moving carrier) involves allowing the foam slurry to flow through an applicator and onto the carrier. In some embodiments, the applicator may be configured to spread the foam slurry uniformly onto the carrier (e.g., a mesh).

[0139] Any of a variety of suitable applicators can be used, such as headboxes, foam nozzles, curtain coaters, and / or slot dies.

[0140] In some embodiments, foam web formation includes drying the foam slurry. For example, see reference... Figure 4 The method shown includes applying heat 416 to the foam slurry 412. In some embodiments, heat 416 may be applied to the foam slurry 412 as it travels along a carrier 414. For example, in some embodiments, applying heat 416 to the foam slurry 412 as it travels along the carrier 414 includes a contact drying process, such that the foam slurry 412 comes into contact with a heated surface. In some such embodiments, the carrier 414 may be a heated surface. According to some embodiments, applying heat 416 to the foam slurry 412 as it travels along the carrier 414 causes a liquid (e.g., water) to evaporate. In some embodiments, the liquid (e.g., water) may be removed from the foam slurry with or without heat applied.

[0141] Foam slurry can be dried using any of a variety of suitable heat sources. In some embodiments, for example, the foam slurry can be dried using one or more heated drying tanks and / or cylinders, air dryers and / or ovens (e.g., by means of air dryers and / or ovens), belt dryers and / or infrared (IR) heaters.

[0142] The filter media described herein can be used in a variety of applications. In some embodiments, the filter media described herein are coalescing filter media. In some embodiments, the filter media described herein are capable of separating and / or configured to separate oil from gases (e.g., compressed gases, air).

[0143] In some embodiments, the filter media described herein are part of a filter element (e.g., a coalescing filter element). That is, the filter media can be incorporated into an article of manufacture suitable for use by the end user.

[0144] Non-limiting examples of suitable filter elements include flat panel filters, metal mesh-backed panel filters, cartridge filters, swirl-in filter elements, integrated filter elements, pleated panel filters, bag filters, mini-pleated filters, V-bank filters (including, for example, 1 to 24 Vs), thermoformed filters, cylindrical filters, conical filters, channel flow filters, and radially sealed filters. Channel flow filters may include alternating rows of flat and corrugated filter media. In some embodiments, these alternating rows may surround a cellular network of channels. In some embodiments, channel flow filters may include channels sealed with adhesive (e.g., channel flow filters may include alternating sealed and unsealed channels). In use, air can flow into the open channels of the channel flow filter, through the filter element, and then out of adjacent open channels.

[0145] Filter elements can have a variety of suitable shapes, such as circular, oval, cubic, and / or prismatic. Filter elements can have any suitable height (e.g., 2 inches to 124 inches for flat plate filters, 4 inches to 124 inches for V-type filters, and 1 inch to 124 inches for cartridge and cylindrical filter media). Filter elements can also have any suitable width (2 inches to 124 inches for flat plate filters and 4 inches to 124 inches for V-type filters). Some filter media (e.g., cartridge and cylindrical filter media) may be characterized by their diameter rather than their width; these filter media can have any suitable diameter value (e.g., 1 inch to 124 inches). Filter elements typically include a frame, which can be made of one or more materials such as cardboard, aluminum, steel, alloys, wood, and polymers.

[0146] The filter elements described herein can be single-stage or multi-stage elements. In some cases, the filter media can be pleated or rolled (e.g., around a core), supported or unsupported, or co-wound / co-pleated with multiple filter media. In some designs, the filter media is pleated with a rolled core at the center.

[0147] In some embodiments, the filter media described herein are integral parts of a filter element and are pleated. As mentioned above, in some embodiments, the filter media described herein can be integral parts of a filter element and can be pleated. It is not intended to be bound by any particular theory, but it is considered advantageous to pleat the filter media in a manner proportional to the number of pleats present to increase its surface area. This increased surface area can improve the filtration efficiency of the filter media. Some pleated filter media may comprise two or more layers connected by a co-pleating process. Pleating can be achieved by forming crisscrosses spaced appropriately apart from each other, thereby allowing the filter media to be folded.

[0148] The pleat height and pleat density (the number of pleats per unit length of the filter medium) can be selected as desired. In some embodiments, the pleat height is greater than or equal to 3 mm, greater than or equal to 5 mm, greater than or equal to 10 mm, greater than or equal to 15 mm, greater than or equal to 20 mm, greater than or equal to 25 mm, greater than or equal to 30 mm, greater than or equal to 35 mm, greater than or equal to 40 mm, greater than or equal to 45 mm, greater than or equal to 50 mm, greater than or equal to 53 mm, greater than or equal to 55 mm, greater than or equal to 60 mm, greater than or equal to 65 mm, greater than or equal to 70 mm, greater than or equal to 75 mm, greater than or equal to 80 mm, greater than or equal to 85 mm, greater than or equal to 90 mm, greater than or equal to 95 mm, greater than or equal to 100 mm, greater than or equal to 125 mm, greater than or equal to 150 mm, greater than or equal to 175 mm, greater than or equal to 200 mm, greater than or equal to 225 mm, greater than or equal to 250 mm, greater than or equal to 275 mm, greater than or equal to 300 mm, greater than or equal to 325 mm, greater than or equal to 350 mm, greater than or equal to 375 mm. mm, greater than or equal to 400 mm, greater than or equal to 425 mm, greater than or equal to 450 mm, greater than or equal to 475 mm, or greater than or equal to 500 mm. In some embodiments, the pleat height is less than or equal to 510 mm, less than or equal to 500 mm, less than or equal to 475 mm, less than or equal to 450 mm, less than or equal to 425 mm, less than or equal to 400 mm, less than or equal to 375 mm, less than or equal to 350 mm, less than or equal to 325 mm, less than or equal to 300 mm, less than or equal to 275 mm, less than or equal to 250 mm, less than or equal to 225 mm, less than or equal to 200 mm, less than or equal to 175 mm, less than or equal to 150 mm, less than or equal to 125 mm, less than or equal to 100 mm, less than or equal to 95 mm, less than or equal to 90 mm, less than or equal to 85 mm, less than or equal to 80 mm, less than or equal to 75 mm, less than or equal to 70 mm, less than or equal to 65 mm, less than or equal to 60 mm, less than or equal to 55 mm, less than or equal to 53 mm, less than or equal to 50 mm, less than or equal to 45 mm, less than or equal to 40 mm, less than or equal to 35 mm, less than or equal to 35 mm. mm, less than or equal to 30 mm, less than or equal to 25 mm, less than or equal to 20 mm, less than or equal to 15 mm, less than or equal to 10 mm, or less than or equal to 5 mm.Combinations of the above ranges are also possible (e.g., greater than or equal to 3 mm and less than or equal to 510 mm, greater than or equal to 10 mm and less than or equal to 510 mm, or greater than or equal to 10 mm and less than or equal to 100 mm). Other ranges are also possible.

[0149] In some embodiments, the pleat density of the filter medium is greater than or equal to 5 pleats per 100 mm, greater than or equal to 6 pleats per 100 mm, greater than or equal to 10 pleats per 100 mm, greater than or equal to 15 pleats per 100 mm, greater than or equal to 20 pleats per 100 mm, greater than or equal to 25 pleats per 100 mm, greater than or equal to 28 pleats per 100 mm, greater than or equal to 30 pleats per 100 mm, or greater than or equal to 35 pleats per 100 mm. In some embodiments, the pleat density of the filter media is less than or equal to 40 pleats per 100 mm, less than or equal to 35 pleats per 100 mm, less than or equal to 30 pleats per 100 mm, less than or equal to 28 pleats per 100 mm, less than or equal to 25 pleats per 100 mm, less than or equal to 20 pleats per 100 mm, less than or equal to 15 pleats per 100 mm, less than or equal to 10 pleats per 100 mm, or less than or equal to 6 pleats per 100 mm. Combinations of the above ranges are also possible (e.g., greater than or equal to 5 pleats per 100 mm and less than or equal to 100 pleats per 100 mm, greater than or equal to 6 pleats per 100 mm and less than or equal to 100 pleats per 100 mm, or greater than or equal to 25 pleats per 100 mm and less than or equal to 28 pleats per 100 mm). Other ranges are also possible.

[0150] Other pleat heights and pleat densities are also possible. For example, the filter media in a flat panel filter or V-type filter can have a pleat height of 1 / 4 inch to 24 inches and / or a pleat density of 1 pleat / inch to 50 pleats / inch. As another example, the filter media in a cartridge filter or cone filter can have a pleat height of 1 / 4 inch to 24 inches and / or a pleat density of 1 / 2 pleat / inch to 100 pleats / inch.

[0151] In some embodiments, the pleats are separated by pleat separators made of, for example, polymers, glass, aluminum, and / or cotton. In other embodiments, the filter element does not have pleat separators. When present, the pleat separators may be positioned on the upstream surface of the filter media and / or on the downstream surface of the filter media. The pleat separators may include portions that separate the pleats and have the following widths (i.e., in the direction separating the pleats): greater than or equal to 1 / 2 inch, greater than or equal to 1 inch, greater than or equal to 1.5 inches, greater than or equal to 2 inches, greater than or equal to 2.5 inches, greater than or equal to 3 inches, greater than or equal to 3.5 inches, or greater than or equal to 4 inches. In some embodiments, the pleat separators include portions that separate the pleats and have the following widths: less than or equal to 5 inches, less than or equal to 4 inches, less than or equal to 3.5 inches, less than or equal to 3 inches, less than or equal to 2.5 inches, less than or equal to 2 inches, less than or equal to 1.5 inches, or less than or equal to 1 inch. Combinations of the above ranges are also possible (e.g., greater than or equal to 3 inches and less than or equal to 2 inches, greater than or equal to 2 inches and less than or equal to 1 inch).

[0152] In some implementations, the filter media includes one or more additional structural elements. For example, the filter media may also include rigid elements, such as polymer mesh and / or metal mesh. As another example, the filter media may also include a screen backing, which can help maintain the filter media in a pleated configuration. Such filter media may be metal mesh backed (e.g., by expanding a metal mesh) and / or include extruded plastic mesh. The filter media may also be self-supporting.

[0153] Some embodiments relate to methods in which fluid passes through a filter medium (e.g., a filter medium positioned in a filter element) as described herein. The fluid may be a gas, such as compressed gas and / or air (e.g., compressed or uncompressed). The fluid passing through the filter medium may also contain one or more contaminants from which the filter medium is to be filtered and / or separated. In some such embodiments, the fluid contains oil as a contaminant.

[0154] Example 1

[0155] This embodiment compares the performance of wet-laid nonwoven fiber webs with different weights per unit area. It also compares the performance of single-layer wet-laid nonwoven fiber webs with that of dual-layer filter media.

[0156] As described elsewhere in this document, selected physical properties of various wet-laid nonwoven fiber webs and filter media were measured and summarized in Tables 3 through 5. All fiber webs compared contained ultrafine glass fibers and an oleophilic resin. The dual-layer filter media consisted of two fiber webs containing ultrafine glass fibers and an oleophilic resin.

[0157] Table 3.

[0158]

[0159] Table 4.

[0160]

[0161] Table 5.

[0162]

[0163] As can be seen from Tables 3 and 5, the coalescence γ of monolayer samples with higher unit area weight is below 30, while the coalescence γ of monolayer samples with lower unit area weight is above 30. This holds true for different efficiencies, saturation pressure drop, permeability, and average flow rate orifice sizes. It can be seen that for monolayer samples with comparable permeability, samples with higher unit area weight have lower saturation pressure drop and higher efficiency. Similarly, for samples with comparable saturation pressure drop, samples with higher unit area weight have higher efficiency (e.g., comparing sample 1 with sample 5, which have comparable average flow rate orifice sizes).

[0164] As can be seen from Tables 3 and 5, the monolayer samples outperformed the bilayer samples with comparable total area weight and average flow rate orifice size. For example, Sample 2 exhibits a lower pressure drop, higher efficiency, and lower coalescence γ than Sample 8, which has comparable permeability. As another example, Sample 2 demonstrates higher efficiency and lower coalescence γ than Sample 9, which has comparable area weight and average flow rate orifice size.

[0165] Table 4 shows the impact of pore size distribution on performance. This can be seen by comparing the data for samples 2 and 3 in Table 5 with the data for samples 7 through 9. The former samples have fewer pores smaller than 1.25 μm in diameter and more pores larger than or equal to 1.25 μm but smaller than 2.5 μm in diameter than the latter samples. The coalescence γ values ​​of the former samples are also all lower than those of the latter samples.

[0166] While numerous embodiments of the invention have been described and illustrated herein, those skilled in the art will readily conceive of a variety of other means and / or structures for performing the functions described herein and / or obtaining the results and / or one or more advantages described herein, and each such variation and / or modification is considered to be within the scope of the invention. More generally, those skilled in the art will readily understand that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and actual parameters, dimensions, materials, and / or configurations will depend on one or more specific applications using the teachings of the invention. Those skilled in the art will recognize or be able to determine many equivalents of specific embodiments of the invention described herein using only conventional experimentation. Therefore, it should be understood that the foregoing embodiments are presented by way of example only, and the invention can be practiced in ways other than those specifically described and claimed within the scope of the appended claims and their equivalents. The invention relates to the individual features, systems, articles, materials, kits, and / or methods described herein. Furthermore, any combination of such features, systems, articles, materials, kits, and / or methods is included within the scope of the invention if two or more such features, systems, articles, materials, kits, and / or methods do not contradict each other.

[0167] All definitions defined and used herein should be understood to take precedence over dictionary definitions, definitions in incorporated documents by reference, and / or the general meaning of the terms they define.

[0168] Unless otherwise expressly stated, names without quantifiers as used herein in the specification and claims shall be understood to mean “at least one / a kind”.

[0169] As used herein in the specification and in the claims, the phrase “and / or” should be understood to mean “any one or two” of the elements so combined, i.e., elements that coexist in some cases and exist separately in others. Multiple elements listed with “and / or” should be understood in the same way, i.e., “one or more” of the elements so combined. In addition to the elements specifically indicated by the “and / or” clause, other elements may optionally be present, whether related to or unrelated to those specifically indicated. Thus, as a non-limiting example, when used in conjunction with open-ended language such as “comprising,” a reference to “A and / or B” may, in one embodiment, refer only to A (optionally including elements other than B); in another embodiment, refer only to B (optionally including elements other than A); in yet another embodiment, refer to both A and B (optionally including other elements); and so on.

[0170] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when items in a separate list are separated, “or” or “and / or” should be understood to be inclusive, i.e., including multiple elements or at least one of the elements in the list, but also including more than one of them, and optionally including additional unlisted items. Only explicitly indicating the opposite terms, such as “only one” or “exactly one”, or when used in a claim, “consisting of…”, will mean including multiple elements or exactly one of the elements in the list. Generally, when preceded by an exclusive term (e.g., “any,” “one,” “only one,” or “exactly one”), the term “or” as used herein should only be understood to indicate an exclusive alternative (i.e., “one or the other, but not both”). “Substantially consisting of…” when used in a claim should have its ordinary meaning as used in the field of patent law.

[0171] As used herein in the specification and in the claims, the phrase “at least one” when referring to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list, but does not necessarily include each and every element specifically listed in the list, nor exclude any combination of elements in the list. This definition also allows for the optional presence of elements other than those specifically indicated in the list of elements referred to by the phrase “at least one,” whether related to or unrelated to those specifically indicated elements. Thus, as a non-limiting example, “at least one of A and B” (or equivalently, “at least one of A or B”, or equivalently, “at least one of A and / or B”) in one embodiment may refer to at least one A, optionally including more than one A, but without B (and optionally including elements other than B); in another embodiment, it may refer to at least one B, optionally including more than one B, but without A (and optionally including elements other than A); in yet another embodiment, it may refer to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other elements); and so on.

[0172] It should also be understood that, unless expressly indicated to the contrary, in any method claimed herein that includes more than one step or action, the order of the steps or actions of the method is not necessarily limited to the listed order of the steps or actions of the method.

[0173] In the claims and the foregoing description, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “constituting,” etc., should be understood as open-ended, that is, meaning including but not limited to. As described in Section 2111.03 of the U.S. Patent Examination Procedure Manual, only the transitional phrases “constituting of” and “substantially consisting of” should be closed or semi-closed transitional phrases, respectively.

Claims

1. A filter medium, comprising: Fiber web, the fiber web comprising glass fiber and resin, wherein: The coalescence γ value of the fiber web is less than or equal to 30. The fiber web has a unit area weight greater than or equal to 130 gsm, and The fiber web is oleophilic.

2. A filter medium, comprising: Fiber web, the fiber web comprising glass fibers, wherein: The weight per unit area of ​​the fiber web is greater than or equal to 130 gsm. The fiber web includes pores. Holes with a diameter less than 1.25 micrometers account for less than or equal to 30% of the total number of pores. Holes with a diameter greater than or equal to 1.25 micrometers and less than 2.5 micrometers account for greater than or equal to 40% of the total number of pores, and The ratio of the number of pores with a diameter less than 1.25 micrometers to the number of pores with a diameter greater than or equal to 1.25 micrometers and less than 2.5 micrometers is less than or equal to 1.

3. The filter medium according to any of the preceding claims, wherein the fiber web is a nonwoven fiber web.

4. The filter medium according to any of the preceding claims, wherein the fiber web is wet-laid.

5. The filter medium according to any of the preceding claims, wherein the fiber web comprises resin.

6. The filter medium according to any of the preceding claims, wherein the resin is oleophilic.

7. The filter medium according to any of the preceding claims, wherein the resin is hydrophilic.

8. The filter medium according to any of the preceding claims, wherein the resin is hydrophobic.

9. The filter medium according to any of the preceding claims, wherein the resin is an acrylic resin.

10. The filter medium according to any of the preceding claims, wherein the fiber web comprises ultrafine glass fibers.

11. The filter medium according to any of the preceding claims, wherein the average diameter of the glass fibers is greater than or equal to 0.2 micrometers and less than or equal to 6 micrometers.

12. The filter medium according to any of the preceding claims, wherein the fiber web comprises synthetic fibers.

13. The filter medium according to any of the preceding claims, wherein the fiber web comprises fibrillated fibers.

14. The filter medium according to any of the preceding claims, wherein the filter medium comprises adhesive fibers.

15. The filter medium according to any of the preceding claims, wherein the filter medium comprises lyocell fibers.

16. The filter medium according to any of the preceding claims, wherein the weight per unit area of ​​the fiber web is greater than or equal to 150 gsm and less than or equal to 400 gsm.

17. The filter medium according to any of the preceding claims, wherein the air permeability of the fiber web is greater than or equal to 5 L / (m²). 2 • seconds) and less than or equal to 400 L / (m 2 ·Second).

18. The filter medium according to any of the preceding claims, wherein the thickness of the fiber web is greater than or equal to 0.1 mm and less than or equal to 5 mm.

19. The filter medium according to any of the preceding claims, wherein the average flow pore size of the fiber web is greater than or equal to 0.5 micrometers and less than or equal to 15 micrometers.

20. The filter medium according to any of the preceding claims, wherein the pore permeability index of the fiber web is greater than or equal to 0.1 and less than or equal to 1.

5.

21. The filter medium according to any of the preceding claims, wherein the filter medium further comprises an additional layer.

22. The filter medium according to any of the preceding claims, wherein the additional layer is a fiber web.

23. The filter medium according to any of the preceding claims, wherein the additional layer is a nonwoven fiber web.

24. The filter medium according to any of the preceding claims, wherein the additional layer is the same as the fiber web.

25. The filter medium according to any of the preceding claims, wherein the additional layer is a protective layer.

26. A filter element comprising a filter medium according to any of the preceding claims.

27. The filter medium or filter element according to any of the preceding claims, wherein the filter medium is pleated.

28. The filter medium or filter element according to any of the preceding claims, wherein the filter medium is wound.

29. The filter medium or filter element according to any of the preceding claims, wherein the filter element is a coalescing filter element.

30. A method comprising passing fluid through a filter medium or filter element according to any of the preceding claims.

31. The method of claim 30, wherein the fluid comprises a gas.

32. The method according to any one of claims 30 to 31, wherein the gas is a compressed gas.

33. The method according to any one of claims 30 to 32, wherein the gas comprises air.

34. The method according to any one of claims 30 to 33, wherein the fluid comprises oil.

Images