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    • 专利摘要:
    HIGH EFFICIENCY, HIGH CAPACITY, GLASS-FREE FUEL FILTERING MEANS AND FUEL FILTERS AND METHODS THAT EMPLOY THEM. High-efficiency, high-capacity, glass-free filtration media include a mixture of non-fibrillated basic length synthetic fibers and fibrillated basic length cellulosic fibers, wherein the fibrillated cellulosic fibers are present in the medium in an amount capable of achieving an overall filtration efficiency under 4 micrometers of 95% or higher and a media gauge filtration capacity ratio of 19,685 mg/m2/mm (0.5 mg/in2/mils) and greater. The filter medium is manufactured by forming a wet-laid sheet from a mixture of fibrous slurry of non-fibrillated basic length synthetic fibers and fibrillated basic length cellulosic fibers, followed by drying the sheet to obtain the filtering medium. Optionally, the filter medium can be provided with a binder resin and can be grooved and/or pleated.
    公开号:BR112014022222B1
    申请号:R112014022222-3
    申请日:2013-03-08
    公开日:2021-05-11
    发明作者:Ina PARKER
    申请人:Ahlstrom-Munksjö Oyj；
    IPC主号:
    专利说明:

    FIELD
    [0001] The embodiments set forth in this context generally refer to glass-free, high-efficiency and high-capacity fuel filtration means, and to fuel filters and fuel filtration methods employing the same BACKGROUND
    [0002] The filtering media that have high efficiency of filtering small particles require, in general, the presence of small pores in the medium, so that the particles to be filtered cannot pass through this medium. Nevertheless, small pores in a medium generally result in low permeability and, therefore, cause a high fluid pressure drop across the medium. When particles are physically trapped on the upstream side of the medium, over time they will gradually block the pores of the medium which, in turn, gradually increases the pressure drop of the fluid through the medium. Thus, the quality of any filtration medium is characterized by the amount of particles that are capable of being captured (also known as “media capacity”), which occurs under a predetermined specific pressure drop. Thus, if the predetermined specific pressure is reached too quickly, the resulting capacity of the medium will be low. The general rule in the filtration industry is that the higher the efficiency possessed by a filtration medium, the lower its capacity. For this reason, an agreement is often needed to achieve both efficiency and acceptable capabilities for the filtration medium.
    [0003] High efficiency filtration media, such as required for fuel filtration, often contain basic length glass microfibers. Glass microfibers have unique filtering properties due to their needle-like fiber shape, stiffness and small dimension. For this reason glass microfibers are widely used in conventional filter media to provide both high efficiency and high capacity.
    [0004] With increasing processing pressure, for example during filtration of heavy duty diesel fuel, concerns have increased that glass microfibers can be washed out of the filter media with the filtered fuel and thus , enter the internal combustion engine and damage it. In order to avoid problems that can result from glass microfibers being bleached from the filter media, efforts have been made to develop high-efficiency, high-capacity, glass-free alternatives to media containing glass microfibers. . Leaching of glass microfibers into the downstream filtrate is not only a concern in fuel filtration from internal combustion engines, but also, for example, in any kind of filtration capable of coming into contact with the human body, by example, through ingestion.
    [0005] Conventional commercially available glass-free filtration medium often contains a base medium that provides the required filtration efficiency, for example, from 100% wood pulp, and a laminated layer of fine long fibers that provide the required filtering capacity. The manufacture of these conventional forms of filter media requires high pressure pinching of the medium as well as a multi-step manufacturing process that includes the lamination of the layers for efficiency and capacity, resulting in high overall production cost. The multilayer structure of these conventional media also often results in relatively greater thickness, which is disadvantageous to the pleated geometry of the resulting filter.
    [0006] For that reason, it would be highly desirable if a filtration medium could be provided that was glass-free (ie, without containing any glass fibers), but still exhibiting high filtering capacity and efficiency. Such filter medium should also have a minimum strength sufficient to be further processed and/or pleated (for example, in order to allow the formation of filter units comprising that medium). It is, therefore, towards the fulfillment of these desirable attributes that the present invention is developed. Summary of Exemplary Achievements
    [0007] According to one aspect, the embodiments set out in this context provide a glass-free non-woven filtration medium which is comprised of a mixture of basic length synthetic fibers and fibrillated cellulosic fibers. According to certain embodiments, basic length synthetic fibers will comprise or more preferably consist of synthetic microfibres. Optionally, the filter medium of some other embodiments may contain non-fibrillated cellulosic fibers in an amount that does not significantly detrimentally affect the filtration efficiency and/or capacity of the medium.
    [0008] Some embodiments will be in the form of a high-efficiency, high-capacity, glass-free non-woven filtration medium comprising a mixture of non-fibrillated basic length synthetic fibers and fibrillated basic length cellulosic fibers, wherein the fibrillated cellulosic fibers are present in the medium in an amount to achieve an overall filtration efficiency under 4 micrometers of about 95% or greater and a filtration capacity to medium gauge ratio of 19.685 mg/m2/mm (0.5 mg/in2/ mils) and greater.
    [0009] Non-fibrillated basic length synthetic fibers can be formed from a thermoplastic polymer selected from the group consisting of polyesters, polyalkylenes, polyacrylonitriles and polyamides. Polyesters, especially polyalkylene terephthalates, are especially desirable. Some embodiments will include non-fibrillated polyethylene terephthalate (PET) basic length microfibers having an average fiber diameter less than about 10 micrometers and an average length less than about 25 millimeters. Basic length synthetic fibers can be present in an amount ranging from about 50% by weight to about 99.5% by weight ODW.
    [0010] The fibrillated basic length cellulosic fibers may comprise fibrillated lyocell nanofibers. Some embodiments will include fibrillated lyocell nanofibers in an amount ranging from about 0.5 to about 50%, by weight, ODW. The fibrillated basic length cellulosic fibers can be provided with a Canadian Standard Refining Degree (CSF) of about 300 ml or less.
    [0011] Some embodiments will include a blend of basic length polyethylene terephthalate microfibers having an average fiber diameter of less than about 10 micrometers and an average length of less than about 25 millimeters that are present in an amount between about from 50% by weight to about 99.5% by weight ODW, and fibrillated basic length lyocell fibers which are provided with a Canadian Standard Refining Grade (CSF) of about 300 ml or less which are present in an amount of at least about 0.5 to about 50% by weight ODW. The fibrillated cellulosic fibers can have an average diameter of about 1000 nanometers or less and an average length of between about 1 mm to about 8 mm.
    [0012] Other components and/or additives may be included in the filter medium. By way of example, some embodiments may include natural wood pulp blended with the non-fibrillated base length synthetic fibers and fibrillated base length cellulosic fibers. If employed, natural wood pulp may be present in an amount of about 25% by weight ODW or less. Wet strength additives, optical brighteners, fiber retaining agents, dyes, fuel-water separation aids (eg silicone additives and associated catalysts), water or oil repellants (eg fluorocarbons) , fire or flame retardants, and the like may also be employed as desired.
    [0013] Binding resins can also be added to the filtration medium to achieve the desired physical properties. If employed, these binder resins can be present in an amount ranging from about 2 to about 50% by weight SDC.
    [0014] The filtration medium can be formed by means of a wet suspension process. By way of example, the filtration medium may be prepared by forming a wet-laid sheet from a fibrous slurry comprised of a mixture of non-fibrillated basic length synthetic fibers and fibrillated basic length cellulosic fibers, and drying of the sheet to obtain the filter medium. The filter medium may be grooved and/or pleated in order to facilitate its use in filter devices (eg filter units associated with on-board fuel filter systems).
    [0015] An advantageous feature of some embodiments of the invention is their ability to separate water from fuel. The filter medium according to the invention can be used to separate water without the addition of silicone.
    These and other attributes of the various embodiments according to the invention will be better understood by reference to their detailed descriptions set out below. Brief Description of the Attached Drawings
    [0017] Figure 1 is a graph of efficiency (%) of multipass (MP) under 4 micrometers versus the content of fibrillated Liocel nanofibers (% by weight) present in the filtration medium.
    [0018] Figure 2 is a schematic view of an arrangement for testing dewatering ability.
    [0019] Figures 3a, 3b, 4a and 4b show the test results of two embodiments of the invention compared to a reference filtration medium. Definitions
    As used in this context and in the appended claims the terms used hereinafter are intended to have the definitions set out below.
    [0021] "Fiber" is a fibrous or filament structure that is endowed with a high proportion of length to diameter.
    [0022] "Medium length fiber" means a fiber that appears naturally or that has been cut or further processed to define relatively short individual segments or lengths.
    [0023] “Nanofibers” means fibers that are endowed with an average diameter of less than about 1000 nanometers.
    [0024] "Fibro so" means a material that is composed predominantly of fiber and/or fiber of basic length.
    [0025] "Non-woven" means a set of fibers and/or fibers of basic length in a texture or weft that are randomly intertwined, tangled and/or bonded together to form a self-supporting structural element.
    [0026] "Synthetic fiber" and/or "artificial fiber" refers to fiber that is chemically produced, manufactured from fiber-forming substances including polymers synthesized from chemical compounds and modified or transformed natural polymer. Such fibers can be produced by means of conventional melt-spinning, solution or solvent spinning, and similar filament production techniques.
    [0027] A "cellulosic fiber" is a fiber composed or derived from cellulose.
    [0028] "Degree of refining" is the measure, in ml, of the rate at which a diluted suspension of medium length fiber can be drained, as described in Canadian TAPPI standard method T 227 om-94 (1994) (hereinafter referred to as sometimes referred to as “Canadian Standard Refining Grade” or “CSF”), the entire contents of which are expressly included herein by reference.
    [0029] "Fibrils" are tiny, tiny, irregular threadlike elements associated with a medium-length fiber.
    "Fibrillated" means fibers of basic length which have been further acted upon to form numerous fibrils and which exhibit a Canadian Standard Refining Degree of about 300 ml or less, preferably about 200 ml or less, typically between about from 10 to about 200 ml.
    [0031] "Non-fibrillated" means unprocessed basic length fibers that are essentially fibril-free and exhibit a Canadian Standard Refining Degree greater than about 500 ml.
    [0032] "Fibrillatable" means non-fibrillated basic length fibers that inherently have the ability to be fibrillated using standard mechanical beaters, refiners and the like employed in the papermaking industry.
    [0033] “Oven dried weight” or “ODW” means the total weight of fibers or texture after drying in a hot air oven at 117°C (350°F) for 5 minutes.
    [0034] "Dry saturated cured" or "SDC" means a medium saturated with resin, subjected to air drying or subjected to drying under low heat for a period of time sufficient to evaporate solvent from the resin and cured in an oven of hot air under 117°C (350°F) for 5 minutes. Detailed Description A. Non-Fibrillated Basic Length Synthetic Fibers
    Virtually any conventional non-fibrillated basic length synthetic fibers can be employed in the filtration medium of this invention. Especially preferred embodiments will include non-fibrillated basic length synthetic fibers formed from a thermoplastic polymer, such as polyesters (e.g., polyalkylene terephthalates such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT) and the like), polyalkylenes (e.g. , polyethylenes, polypropylenes and the like), polyacrylonitriles (PAN), and polyamides (nylons, e.g., nylon-6, nylon 6.6, nylon-6.12, and the like). Basic length PET fibers are preferred.
    [0036] Synthetic basic length fibers are most preferably micro fibers, that is, basic length fibers that have average fiber diameters of less than about 10 micrometers, sometimes less than about 8 micrometers or even less of about 5 micrometers, and lengths of less than about 25 millimeters, sometimes less than about 10 millimeters, such as less than about 6.5 millimeters (eg less than about 3.5 millimeters). mm).
    Particularly preferred synthetic basic length microfibres are water-dispersible polyalkylene terephthalate microfibres. Preferred are basic length polyethylene terephthalate (PET) microfibers. According to certain preferred embodiments, basic length PET microfibers are the result of washing in water non-water-dispersible sulfopolyester fibers which are endowed with a glass transition temperature (Tg) of at least 25°C, with the sulfopolyester comprising: (i) about 50 to about 96 mol% of one or more isophthalic acid or terephthalic acid residues; (ii) about 4 to about 30 mols%, based on total acid residues, of a sodiosulfoisophthalic acid residue; (iii) one or more diol residues wherein at least 25 mol%, based on the total diol residues, is a poly(ethylene glycol) having an H-(OCH2-CH2)n-OH structure, wherein n is an integer in the range of 2 to about 500; and (iv) 0 to about 20 mols%, based on total repeating units, of residues of a branching monomer that is provided with 3 or more hydroxyl, and/or carboxyl functional groups. These preferred basic length PET synthetic microfibers and their production methods are more fully described in published US patent applications Nos. 2008/0311815 and 2011/0168625 (the entire contents of each being expressly included herein by reference) and are found commercially available from Eastman Chemical Company, Kingsport, TN.
    [0038] Basic length synthetic fibers will be employed in the filtration medium in an amount between about 50% by weight, up to about 99.5% by weight, ODW, preferably between 75% by weight, up to about 97.5% by weight ODW. Especially preferred embodiments will include the basic length synthetic fibers in an amount ranging from about 80% by weight to about 90% by weight ODW. B. Cellulosic Fibers
    [0039] The filtration medium will necessarily include fibrillated basic length cellulosic fibers having a Canadian Standard Refining Degree (CSF) of about 300 ml or less, preferably about 200 ml or less, typically between about 10 to about 200 ml.
    Preferred fibrillatable cellulosic base length fibers are those produced by direct dissociation and spinning of wood pulp in an organic solvent, such as an amine oxide, and are known as lyocell base length fibers. The fibrillatable basic length cellulose fibers can thus be fibrillated by being subjected to conventional mechanical beaters, refiners and the like which are employed in the papermaking industry.
    [0041] The fibrillated cellulosic basic length fibers will be employed in the filtration medium in an amount between about 0.5 to about 50% by weight, ODW, preferably between 2.5 to about 25%, in weight, ODW. Especially preferred embodiments will include the fibrillated cellulosic base length fibers in an amount of between about 10 to about 20%, by weight, ODW.
    Especially preferred fibrillated cellulosic basic length fibers include lyocell basic length fibers. Lyocell basic length fibers are most preferably nanofibers, i.e. basic length fibers having an average diameter of about 1000 nanometers or less, or sometimes about 400 nanometers or less, for example about 100 nanometers . Some especially preferred embodiments will include fibrillated basic length cellulosic fibers of about 250 nanometers. The average length of the basic length lyocell nanofibers is typically between about 1 mm to about 8 mm, or between about 2 mm to about 6 mm, or about 3 mm to about 4 mm.
    Preferred fibrillated lyocell nanofibers are commercially available from Engineered Fibers Technology, LLC under the tradename EFTec™ Nanofibrillated Fibers. Preferred commercially available forms of fibrillated lyocell nanofibers include EFTec™ L010-4, L040-4 and L200-6 Nanofibrillated fibers which are provided with fibrillation degrees under 4mm or 6mm fiber length of <10 CSF, 40 CSF and 200 CSF, respectively.
    Other non-fibrillated cellulosic basic length fibers may optionally be blended with the non-fibrillated synthetic basic length fibers and the fibrillated cellulosic basic length fibers in order to impart additional stiffness to the filtration medium. For that reason, according to some embodiments, the addition of 0 to about 25% by weight ODW may be desired, e.g. from 0% by weight to about 20% by weight ODW or up to about 15% by weight ODW of natural wood pulp (non-lyocell) basic length fibers. A variety of non-fibrillated, non-lyocell, cellulosic base length fibers are commercially available and can be blended with the other components of the filter media set forth in this context as may be desired. C. Other Components
    [0045] The filtration medium according to certain embodiments may include a resin binder to achieve the desired physical properties. For this purpose any suitable resin binders can be added to the filtration medium. Examples of suitable resin binders which may optionally be employed include polymers such as styrene acrylic, acrylic, polyethylene vinyl chloride, styrene butadiene rubber, polystyrene acrylate, polyacrylates, polyvinyl chloride, polynitriles, polyvinyl acetate, derivatives of polyvinyl alcohol, starch polymers, epoxide, phenolics and their combinations, including both water-based and solvent-based versions. In some cases the resin binder may be in the form of a latex, such as a water-based emulsion.
    [0046] If employed, the resin binder may be present in amounts between about 2 to about 50% by weight SDC, preferably between 10 to about 30% by weight SDC. Especially preferred embodiments will include the resin binder in an amount ranging from about 12 to about 25%, by weight, SDC.
    Preferred resin binders include phenolic resins, acrylic resins (eg, acrylic vinyl latex resins), melamine resins, silicone resins, epoxy resins, and the like. A phenolic resin (phenol formaldehyde) that may be employed includes DURITE® SL161A commercially available from Momentive Specialty Chemicals Inc. of Louisville, KY. A suitable latex-based resin filler that may be employed is PD 0458 M1 (a branched nonylphenol polyoxymethylene ether phosphate dispersed in formaldehyde) commercially available from the HB Fuller Co. of St. Paul, MN. A suitable melamine binder resin may be the ASTRO® Celrez PA-70 methylated melamine resin system commercially available from Momentive Specialty Chemicals Inc. of Louisville, KY. Acrylic resins that are suitable include the ACRODUR® formaldehyde-free water-based acrylic resins, commercially available from BASF Corporation.
    [0048] The filter medium may also contain conventionally employed wet deposited filter media, such as, for example, wet strength additives, optical brighteners, fiber retention agents, dyes, fuel - water separation aids (eg, silicone additives and associated catalysts), water or oil repellants (eg, fluorocarbons), fire or flame retardants, and the like. If present, these additives can be included in amounts of up to about 20% by weight ODW, preferably up to about 10% by weight ODW, for example, between about 1 to about 10%, in Weight. D. Preparation Methods
    [0049] The filtration medium described in this context can be prepared by any conventional "wet deposited" papermaking technology. Thus, for example, predetermined amounts of the non-fibrillated synthetic staple length fibers and the fibrillated cellulosic staple length fibers (together with any optional components such as natural wood pulp fibers and/or additives) and water can be placed in a pulper or mixer. The fibers are mixed and dispersed by the pulper or mixer evenly in the water to form a slurry batch. A certain amount of mechanical work can also be performed on the fibers to alter physical parameters such as permeability, surface properties and fiber structure. The slurry batch can thereafter be transferred to a mixing box where additional water is added and the fibers are homogeneously mixed. The mixed slurry can then be transferred to a machine box where one or more batches of slurry can be combined, allowing for a transfer from one batch to a continuous process. The consistency of the slurry is defined and maintained by stirring to ensure uniform dispersion of the fibers. In this regard, the slurry can be optionally passed through a refiner to adjust the physical parameters.
    [0050] The slurry is then transferred to a moving wire mesh where water is removed by means of gravity and suction. When the water is removed, the fibers form into a non-woven fibrous mat or sheet that is endowed with characteristics determined by a number of process variables, including, for example, slurry flow rate, machine speed, and drainage parameters. The formed sheet can optionally be compressed while in the wet condition in order to compact the paper and/or modify its surface characteristics. The wet paper mat is then moved through a drying section comprised of heated rollers (or "cans" in technical jargon) where most of the remaining entrained water is removed. The dried texture can then receive a binder which can be applied by any conventional means, such as dipping, spray coating, roller application (engraving) and the like. Heat can then be applied subsequently to dry the texture.
    [0051] If used as a pleated filtration medium, the dry texture can be advantageously subjected to grooving in the machine direction (longitudinal) using conjugated male/female rollers. If employed, the medium may be provided with about 50 slots extending longitudinally over 200 mm of width of the medium. Each groove will thus preferably have a nominal width of about 4 mm. A typical high efficiency fuel class that contains grooved glass is endowed with dimensions such as a total SD gauge (saturated and dry, but not cured) of about 0.9652 mm (38 mils), SD groove depth of about 0.3302 mm (13 mils), and SD optical gauge (optical measurement of the thickness of the middle in a groove, therefore representing the corresponding flat thickness) of about 0.7112 mm (28 mils).
    [0052] The finished filter medium (optionally grooved) can then be collected on a roller for further processing into finished filter products. For example, one or more sheets of finished filter media can be laminated with one or more sheets of material (e.g., at least one additional filter media layer, backing layer, and the like) to achieve physical and performance characteristics. desired. The filter medium may also be pleated and taken in the form of a cylindrical filter cartridge which may then be provided as a component part of a filter unit (e.g. an on-board fuel filter unit). Co-pleating the filter medium with a layer of wire mesh may be desirable in certain end-use applications.
    [0053] The basis weight of the finished filter medium is not of major importance. Thus, the finished filter medium can have a basis weight of at least about 15 grams per square meter (gsm), more preferably at least about 35 gsm to about 300 gsm. Some embodiments of the filter medium can have a basis weight in the range of from about 50 to about 200 gsm.
    [0054] The present invention will be further illustrated by means of its non-limiting examples set out below. EXAMPLES Example 1
    In the examples described below, the following components were employed: • PET microfibers: Basic length non-fibrillated PET microfibers having an average diameter of 2.5 micrometers, commercially available from Eastman Chemical Company, • Lyocel Fibrillated: Nanofibers of commercially available fibrillated lyocell from Engineered Fibers Technology LLC under the trade name EFTec™ fibers with Lyocel L010 having a CSF of < 10 ml; Lyocel L040 having a CSF of 40 ml; and Liocel L200 having a CSF of 200 ml. • Sodra Red: Chemi-Thermal-Mechanical (CTM) Softwood Pulp with a Refining Grade of 600-700ml and SR of 15, and a pH of 7.5, manufactured by Sodra, Sweden. The mass is 4 cm3/g. • Alabama Pine or Alabama River Softwood: Elemental Chlorine-Free Kraft Pulp (ECF) from Southern Softwood manufactured by Georgia-Pacific, USA with CSF ranges ranging from 300 to 740 ml and mass from 1.48 - 2.1 cm3/g. • HPZIII: Mercerized Southern Softwood sourced from Buckeye Technologies, Inc. having an average fiber length of 1.8 mm and mass of 7.3 cm3/g. • Northern softwood GRAND PRAIRIE: sourced from Weyerhaeuser. • Co. having an average fiber length of 2.3 mm, CSF ranges between 648 - 300, mass ranges between 1.52 - 1.24 cm3/g. • FIBRIA: Fibria ECF Bleached Eucalyptus Pulp from Aracruz Cellulose (USA) Included with a drainage capacity of 22-55. SR and a fiber length of about 0.70mm • KYMENE: A wet strength additive consisting of 12-13% solids of an aqueous solution of a cationic amine polymer adduct - epichlorohydrin having a specific gravity of 1 .03, the pH is 3.5-4.5 and the solution contains 12-13% solids. • MOMENTIVE 161A: EPON™ Resin 161, a multifunctional epoxidized novolac phenolic resin binder commercially available from Momentive Specialty Chemicals, Inc. and having an epoxide equivalent weight of 169-178 g/eq (ASTM D1652), a viscosity ( 25°C) of 18-28 Pa.s (18,000-28,000 cP) (ASTM D2196) and a density (25°C) of 1198.26 g/l (10.0 lb/Gal). Procedure:
    [0056] The samples were produced using a manual sheet mold deposited by wet laboratory. The supply as described in the recipe was mixed with 2 liters of tap water and disintegrated with a conventional laboratory disintegrator (Noram) under 1500 revolutions. The supply was then poured into the wet mold and diluted with approximately 25 liters of running water, agitated 3 times with a pedal stirrer, and drained through a conventional paper machine screen.
    [0057] The handsheets were then squeezed with a wringer roller passed 3 times, pre-dried in a table speed oven for 5 minutes at 176.5 °C (350° °F) and subsequently subjected to drying in an oven for 5 minutes at 176.5°C (350°F). Raw physical data, such as gross basis weight, gauge, air permeability, were collected immediately after oven drying.
    The samples were then saturated with a standard phenolic resin (161A from Momentive Specialty Chemicals, Inc.) to a content of 6% (resin bath bath solids were 18% in methanol as solvent). The samples were then air-dried for 24 hours at ambient conditions, and cured to reach the SDC (dry saturated cured) level under 176.5°C (350°F) for 5 minutes. SDC basis weight was recorded immediately following curing, and other SDC data such as SDC gauge and SDC air permeability were measured subsequently. Specifically, these physical parameters were measured as follows:
    [0059] SDC gauge: The gauge (thickness) of the SDC medium was measured using an 89-100 Thickness Tester from Thwing-Albert Instrument Company according to TAPPI Standard T411, “Paper thickness (gauge) , cardboard and board combined” (fully included in this context by reference).
    [0060] Air Permeability of SDC: The air permeability of the SDC medium was tested with an FX3300 LabAir IV Air Permeability Tester from TexTest, in accordance with ASTM D737, “Standard Test Method for Air Permeability of Textile Fabrics ” fully included in this context by reference). Measurements were recorded under 125 Pa at 0.028 m3/min. [Cubic Feet per Minute (cfm)] per area of 0.093 m2 (one square foot).
    [0061] Filtration performance was measured using a multi-pass (MP) tester in accordance with ISO 19438:2003, "Diesel and gasoline fuel filters for internal combustion engines - Filtration efficiency using particle counting and contaminant holding capacity” (included in this context by reference). ISO 19438:2003 specifies a multi-pass filtration test, with a continuous injection of contaminants using the online particle counting method, to evaluate the performance of fuel filters for internal combustion engines subjected to a flow rate. constant of the test liquid. The test procedure determines the contaminant removal capability of a filter, its particulate removal characteristics and differential pressure. ISO 19438:2003 is applicable to filter elements that have a nominal flow between 50 l/h and 800 l/h; however, upon agreement between the filter manufacturer and the user, and with minor modifications, the procedure is permitted for application to fuel filters with higher flow rates. The parameters used in the PM Test are: Test powder used: ISO Fine Flow rate: 1.89 liters/min. Oil viscosity: 15 mm2/s @ 43°C = Gravimetric injection under 43°C: 75.7 mg/liter BUGL (Basic Upstream Gravimetric Level): 10 mg/liter
    [0062] Hand sheets were prepared using 2.5 micrometer PET microfiber (Eastman Chemical Company), different grades of fibrillated lyocell (Grades L010, L040, L200 from Engineered Fibers Technology, LLC), and wood pulp of three different types. Most handsheets also contained Kymene, a wet strength additive, to mimic production conditions, in quantities indicated in the tables below.
    [0063] The "Capacity/Gage Ratio" was calculated by dividing the average capacity (mg/in2) by the average gauge (mils) in order to normalize the capacity data capable of accounting for different sheet gauge thicknesses. The “overall efficiency under 4 micrometers” was determined using the multipass filtering test (MP) described above. TABLE 1


    [0064] The data in Table 1 above demonstrate that the filtration medium formed from PET microfibers and fibrillated lyocell microfibers exhibited an advantageous capacity/gauge ratio of 19.685 mg/m2/mm (0.5 mg/in2/mils) and greater at approximately 98% efficiency under 4 micrometers or greater. Example 2
    [0065] Example 1 was repeated with the exception that the filter medium was formed on a standard Fourdrinier wet papermaking line. The results of these tests are illustrated in Table 2 below. TABLE 2

    [0066] The data in Table 2 above confirm that the capacity / gauge ratio is 19.685 mg/m2/mm (0.5 mg/in2/mils) and higher for all basis weights, even though the ratio has the trend decreasing with an increase in basis weight. The data also demonstrate that the medium had an acceptable filtration efficiency of 95% or greater under 4 micrometers, typically 97% or greater under 4 micrometers. Example 3
    [0067] Example 1 was repeated with different amounts of natural wood pulp mixed with PET microfibers and fibrillated lyocell microfibers in varying amounts. The data are shown in Table 3 below. TABLE 3

    [0068] The data in the previous table demonstrate that the addition of natural wood pulp to the mixture of PET nanofibers and fibrillated lyocell deteriorates the capacity properties of the filtration medium. At levels above about 20-25% by weight, wood pulp can cause the capacity/gauge ratio to drop below 19.685 mg/m2/mm (0.5 mg/in2/mils) and, therefore, it should be avoided. Example 4
    Example 1 was repeated with different amounts of fibrillated lyocell. The data are shown below in Table 4. TABLE 4

    [0070] The data in Table 4 above shows that fibrillated basic length lyocell fibers when added in a relatively small amount (e.g., about 2.5% by weight or more) to PET microfibers increase filtration efficiency. the middle one. This is further demonstrated by the graph of Figure 1. Specifically, Figure 1 demonstrates that under 2.5% by weight fibrillated lyocell increased filtration efficiencies across all basis weights of the resulting filter medium. Thus, for higher basis weight media, amounts of fibrillated lyocell less than 2.5% by weight may be present in order to achieve filtration efficiency of about 98% or greater.
    [0071] The data also show that, although the relative amounts of PET nanofibers and fibrillated lyocell nanofibers can be varied, in general it is the fibrillated lyocell nanofibers that contribute to increased efficiency, while PET nanofibers contribute for increased filtering capacity. With higher basis weight, the filter media generally exhibits higher capacity due to the increase in gauge, and the pore structure becomes smaller and more compact due to the filtration depth. For this reason, using the same two components, the content of fibrillated lyocell nanofibers must be decreased with an increase in basis weight in order to maintain the same level of efficiency (which in this case means that the capacity will increase). With different grades (ie different CSF characteristics) of fibrillated lyocell nanofibers, the absolute amount of fibers will vary greatly. For example, the data demonstrates that substantially doubling the amount of EFTec™ L200 lyocell nanofibers produces the same level of efficiency when compared to EFTec™ L010 lyocell nanofibers. The data generally show that a minimum amount of about 2.5% by weight of EFTec™ L010 fibrillated lyocell nanofibers will be required, whereas a maximum of 50% by weight of lyocell nanofibers will be required fibrillated EFTec™ L200 to achieve acceptable efficiency performance characteristics. Example 5
    [0072] Experimental glass-free media of this invention were grooved to obtain the dimensions shown below:

    [0073] The above table shows that although the actual “flat” gauge of the experimental medium is much smaller than the actual “flat” gauge of the commercial glass medium, the same overall grooved gauge could be obtained by transmitting a very large groove. bigger. This means that additional three-dimensional filtering area is created, resulting in additional filtering performance in a converted filter. It has also been noted that other handsheets embodying the present invention may be grooved without cracking under SD Groove Depth up to 0.7366 mm (29 mils). Example 6
    [0074] The water-separating ability of the filtration medium according to the invention was tested in a manner set out below. Description of Test Methods:
    [0075] There are a number of standards available for evaluating fuel/water separation. SAE J1839 is applied for the evaluation of raw water removal (particle size 180 - 260 µm). The water repelling medium can efficiently remove these large droplets. ISO16332 requires a particle size of 300 µm, a larger droplet size. Furthermore the specified interfacial tension is 10-15 mN/m lower than SAE J1839.
    [0076] SAE J 1488 and ISO4020 are standards for determining the ability of a fuel/water separator to separate emulsified or finely dispersed water from fuels. SAE J1488 cannot be considered similar to ISO 4020 as ISO 4020 does not define the droplet size. In addition, ISO 4020 is typically used for low fuel flow testing, while SAE J1488 can be used for high fuel flow rates up to 100 l/min. The main differences include the fuel pump and test water concentration, SAE J1488 requiring a centrifugal pump with strong mechanical shear and 0.25% water concentration (producing finer water, better dispersed) compared to ISO 4020 which recommends 2% water injection via a low-shear diaphragm pump, resulting in larger droplets and high probability of droplet agglomeration. It can thus be inferred that SAE J1488 is the most rigorous test.
    [0077] The separation of emulsified water from diesel oil becomes more difficult when the surface tension of the fuel is high; an example of this is the use of ultra-low sulfur diesel fuel (ULSD). The increased tensioactivity manifests itself in the form of decreased fuel/water interfacial tension (IFT) and micro-separometer rating (MSEP). The result is increased stability of the water-in-fuel emulsion. The impact of raw and emulsified water on engines is widely known and well documented both in the literature and in SAE testing standards SAE J 1488 and SAE J1839. The removal of raw water in relation to fuels usually does not present technical difficulties. However, as the stability of water in the fuel emulsion increases, the ease of removal of this water decreases to become a challenge.
    [0078] Within the test methods mentioned the exact details of the circuit and the method of generating the droplets are not common, thus there is potential for variation in the installed equipment and exact protocol. Thus it can be said that the size of the water droplet and the diesel IFT vary both within the test protocol and within the industry in general. Due to the fact that the use of the SAE standard is voluntary, individual companies may choose to apply the standard to different degrees to evaluate their products. For the test described in this context, the method is based on the test methods mentioned above. Ultra-low sulfur diesel fuel is made from reservoir 1 via a pump 2 at this point at which water is added via a peristaltic pump 3. The fuel supply then passes through a series of separating cartridges of fuel-water 4 before returning to reservoir 1. After pump 2 and before fuel-water separation cartridges 4, a portion of the flow may be passed through a test cell 5, which contains a smooth sheet of the test medium, subsequently returning to the main circuit and flowing through the fuel-water separation cartridges 4 and back to reservoir 1 (Figure 2).
    [0079] Samples are removed from the reservoir, upstream and downstream of each test cell 5 at various intervals. Analysis using Karl Fischer titration allows the water content to be determined. The data collected allows the assessment of water removal facilitated by the sample in each test cell 5, one cell will contain a control medium against which the other cells are compared. This will help to minimize the sample-to-sample fuel variation.
    [0080] The Karl Fischer titration cell contains an anodic solution plus analyte. The anodic solution consists of an alcohol (ROH), a base (Base), sulfur dioxide (SO2) and iodine (I2). A typical alcohol that may be used is methanol or diethylene glycol mono ethyl ether, and a common base is comprised of imidazole.
    [0081] The titration cell also consists of a smaller compartment with a cathode immersed in the anodic solution of the main compartment. The two compartments are separated by an ion permeable membrane.
    [0082] The Pt anode generates I2 current is provided through the electrical circuit. The liquid reaction as illustrated below is the oxidation of SO2 via I2. One mole of I2 is consumed for every mole of H2O. In other words, 2 moles of electrons are consumed for every mole of water r. Base•I2 + Base•SO2 + Base + H2O→ 2BaseH+I− + BaseSO3 BaseSO3 + ROH → BaseH+ROSO3−
    [0084] The endpoint is most often detected by means of a bipotentiometric method. A second pair of Pt electrodes is immersed in the anodic solution. The detector circuit maintains a constant current between the two detector electrodes during titration. Before the equivalence point, the solution contains I - but little I2. At the equivalence point, excess I2 appears and a sudden drop in voltage marks the end point. The amount of current needed to generate I2 and reach the end point can be used to calculate the amount of water in the original sample.
    [0085] Description of Samples: Machine Test Sample according to the invention (A): Base weight: 38.46 kg/ream [84.8 lbs/Ream] (grooved); 42.91 kg/ream [94.6 lbs/Ream] (plain) Fiber Supply: Polyester and fibrillated cellulose Resin: Phenolic Resin without silicone additive Reference (R): SD Base weight: 58.96 kg/Ream (130 lbs /Ream)
    Fiber supply: glass and wood pulp mixture Resin: Phenolic resin with silicone additive Experimental Results and Data:
    [0086] Experimental samples according to the invention, identified as versions A1 to A4, were tested against a fuel-water separation medium, reference R with the internal test method as described above in this context. The results indicated that the samples according to the invention provide a higher water removal efficiency, even without a silicone treat, than a fuel separation class - standard, commercial reference water. Silicone is commonly used as an additive to the resin in the cellulose-based fuel-water separation medium to increase water repellency and thus is known to increase the fuel-water separation efficiency in the cellulose-based medium. The test results shown in Figures 3a, 3b, 4a and 4b show better or equal water separating ability and improved pressure drop during operation over a reference medium with silicone additive.
    [0087] Although the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but rather is intended to be protected various modifications and equivalent provisions included within the spirit and scope thereof.
    权利要求:
    Claims (17)
    [0001]
    1. A glass-free, high-efficiency, high-capacity filtration medium characterized by comprising: a mixture of non-fibrillated staple synthetic microfibers and fibrillated staple cellulosic fibers, wherein the non-fibrillated staple synthetic microfibers have an average fiber diameter of less than 10 microns and an average fiber length of less than 25 millimeters and are formed from a thermoplastic polymer selected from the group consisting of polyesters, polyalkylenes, polyacrylonitriles and polyamides, where fibrillated cellulosic fibers exhibit a value for the Canadian method for drainage capacity (Canadian Standard Freeness, CNF) of 300 mL or less and are present in the medium in an amount to achieve an overall filtration efficiency at 4 microns of 95% or greater and a filtration capacity to medium thickness ratio of 19.685 mg/m2/mm [(0.5 mg/in /mils)] and higher, and in which the synthetic staple fibers are present in an amount between 50% by weight and 99.5% by weight ODW.
    [0002]
    A filter medium according to claim 1, characterized in that the non-fibrillated discontinuous synthetic microfibers have an average fiber diameter of less than 8 microns.
    [0003]
    A filtration medium according to claim 1, characterized in that the non-fibrillated discontinuous synthetic microfibers have an average fiber diameter of less than 5 microns.
    [0004]
    A filtration medium according to claim 1, characterized in that the non-fibrillated discontinuous synthetic microfibers are polyethylene terephthalate microfibers.
    [0005]
    A filtration medium according to claim 1, characterized in that the fibrillated discontinuous cellulosic fibers comprise fibrillated lyocell nanofibers.
    [0006]
    6. Filtration medium according to claim 5, characterized in that the fibrillated lyocell nanofibers are present in an amount between 0.5% and 50% by weight ODW.
    [0007]
    Filter medium according to claim 6, characterized in that the medium has a basis weight between 15 g/m2 and 300 g/m2.
    [0008]
    8. A filtration medium according to claim 1, characterized in that the fibrillated cellulosic fibers have an average diameter of 1000 nanometers or less and an average length between 1 mm and 8 mm.
    [0009]
    A filter medium according to claim 1, characterized in that it additionally comprises natural wood pulp mixed with the non-fibrillated synthetic staple fibers and the fibrillated staple cellulosic fibers.
    [0010]
    A filter medium according to claim 9, characterized in that natural wood pulp is present in an amount of 25% by weight ODW or less.
    [0011]
    A filter medium according to claim 10, characterized in that the natural wood pulp is present in an amount of 20% by weight ODW or less.
    [0012]
    A filter medium according to claim 1, characterized in that it additionally comprises a resin binder.
    [0013]
    A filter medium according to claim 12, characterized in that the resin binder is at least one selected from the group consisting of styrene acrylic, acrylic, polyethylene vinyl chloride, styrene butadiene rubber, polystyrene acrylate, polyacrylates, polyvinyl chloride, polynitriles, polyvinyl acetate, polyvinyl alcohol derivatives, starch polymers, epoxy, phenolics and combinations thereof.
    [0014]
    A filter medium according to claim 12, characterized in that the resin binder is present in an amount between 2 and 50% by weight of SDC.
    [0015]
    15. A filter medium according to claim 1, characterized in that it additionally comprises at least one additive selected from the group consisting of wet strength additives, optical whitening agents, fiber retention agents, dyes, coloring aids. fuel-water separation and flame or fire retardants.
    [0016]
    A filtering medium according to claim 1, characterized in that it comprises slots separated latitudinally and extending longitudinally.
    [0017]
    A filter medium according to claim 1, characterized in that the filter medium is pleated.
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    同族专利:
    公开号 | 公开日
    CN104144735A|2014-11-12|
    KR101739746B1|2017-06-08|
    CN104144735B|2017-06-30|
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    CA2873830C|2016-10-11|
    US9662600B2|2017-05-30|
    US20130233789A1|2013-09-12|
    WO2013132161A3|2014-01-09|
    US10363505B2|2019-07-30|
    CA2873830A1|2013-09-12|
    EP2822670B1|2020-06-10|
    KR20140129004A|2014-11-06|
    US20170319994A1|2017-11-09|
    WO2013132161A2|2013-09-12|
    EP3725387B1|2021-11-17|
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    法律状态:
    2018-03-27| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2018-08-21| B25A| Requested transfer of rights approved|Owner name: AHLSTROM-MUNKSJOE OYJ (FI) |
    2019-09-10| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-09-01| B07A| Application suspended after technical examination (opinion) [chapter 7.1 patent gazette]|
    2020-12-08| B15G| Petition not considered as such [chapter 15.7 patent gazette]|
    2021-03-16| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-05-11| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 08/03/2013, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US13/417,022|US9662600B2|2012-03-09|2012-03-09|High efficiency and high capacity glass-free fuel filtration media and fuel filters and methods employing the same|
    US13/417,022|2012-03-09|
    PCT/FI2013/050262|WO2013132161A2|2012-03-09|2013-03-08|High efficiency and high capacity glass-free fuel filtration media and fuel filters and methods employing the same|
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