High efficiency and high capacity glass-free fuel filtration media and fuel filters and methods employing the same

1. High efficiency and high capacity filtration media comprising:

a blend of synthetic non-fibrillated staple microfibers and fibrillated cellulosic staple fibers, wherein

the synthetic non-fibrillated staple microfibers have an average fiber diameter of less than about 10 microns and an average fiber length of less than about 25 millimeters and are formed of a thermoplastic polymer selected from the group consisting of polyesters, polyalkylenes, polyacrylonitriles and polyamides, and wherein

the fibrillated cellulosic fibers are present in the media in an amount to achieve a multipass dust holding capacity of 10 mg/in 2 and greater, and a multipass filtration efficiency at 1.5 microns of greater than 50%.

2. The filtration media of claim 1 , wherein the synthetic non-fibrillated staple microfibers have an average fiber diameter of less than about 8 microns.

3. The filtration media of claim 1 , wherein the synthetic non-fibrillated staple microfibers have an average fiber diameter of less than about 5 microns.

4. The filtration media of claim 1 , wherein the synthetic non-fibrillated staple microfibers are polyethylene terephthalate microfibers.

5. The filtration media of claim 4 , wherein the polyethylene terephthalate microfibers are the water-washed residue of water non-dispersible sulfopolyester fibers having a glass transition temperature (Tg) of at least 25° C., the sulfopolyester comprising (i) about 50 to about 96 mole % of one or more residues of isophthalic acid or terephthalic acid; (ii) about 4 to about 30 mole %, based on the total acid residues, of a residue of sodiosulfoisophthalic acid; (iii) one or more diol residues wherein at least 25 mole %, based on the total diol residues, is a poly(ethylene glycol) having a structure H—(OCH 2 —CH 2 ) n —OH , wherein n is an integer in the range of 2 to about 500; and (iv) 0 to about 20 mole %, based on the total repeating unites, of residues of a branching monomer having 3 or more hydroxyl, and/or carboxyl functional groups.

6. The filtration media of claim 1 , wherein the synthetic non-fibrillated staple microfibers are present in an amount between about 50 wt. % to about 99.5 wt. % ODW.

7. The filtration media of claim 1 , wherein the fibrillated cellulosic staple fibers comprise fibrillated lyocell nanofibers.

8. The filtration media of claim 7 , wherein the fibrillated lyocell nanofibers are present in an amount of between about 0.5 to about 50 wt. % ODW.

9. The filtration media of claim 8 , wherein the media has a basis weight of between about 15 gsm to about 300 gsm.

10. The filtration media of claim 1 , wherein

the synthetic staple fibers comprise polyethylene terephthalate microfibers which are present in an amount between about 50 wt. % to about 99.5 wt. % ODW, and wherein

the fibrillated cellulosic staple fibers comprise fibrillated lyocell fibers having a Canadian Standard Freeness (CSF) of about 300 mL or less which are present in an amount of at least about 0.5 to about 50 wt. % ODW.

11. The filtration media of claim 1 , wherein the fibrillated cellulosic fibers have an average diameter of about 1000 nanometers or less and an average length between about 1 mm to about 8 mm.

12. The filtration media of claim 1 , further comprising natural wood pulp blended with the synthetic non-fibrillated staple fibers and fibrillated cellulosic staple fibers.

13. The filtration media of claim 12 , wherein the natural wood pulp is present in an amount of about 25 wt. % ODW or less.

14. The filtration media of claim 13 , wherein the natural wood pulp is present in an amount of about 20 wt. % ODW or less.

15. The filtration media of claim 1 , further comprising a resin binder.

16. The filtration media of claim 15 , having a SD machine direction stiffness according to TAPPI Standard T543 of greater than about 2.5 g.

17. The filtration media of claim 15 , having a SD machine direction tensile strength according to TAPPI Standard T494 of greater than about 20 lb/in.

18. The filtration media of claim 15 , having a SD dry burst strength according to TAPPI Standard T403 om-02 of greater than about 30 psi.

19. The filtration media of claim 15 , wherein 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 derivates, starch polymers, epoxy, phenolics and combinations thereof.

20. The filtration media of claim 15 , wherein the resin binder is present in an amount of between about 2 to about 50 wt. % SDC.

21. The filtration media of claim 1 , further comprising at least one additive selected from the group consisting of wet strength additives, optical brighteners, fiber retention agents, colorants, fuel-water separation aides, and flame or fire retardants.

22. The filtration media of claim 1 , comprising longitudinally extending and latitudinally separated grooves.

23. The filtration media of claim 1 , wherein the filtration media is pleated.

24. A multilayer filter comprising a first filtration layer comprised of the filtration media of claim 1 , and at least one additional material layer.

25. The multilayer filter of claim 24 , wherein the at least one additional material layer comprises a second filtration media layer that is laminated to the first filtration layer.

26. The multilayer filter of claim 24 , wherein the at least one additional material layer comprises a supporting layer to support the first filtration layer.

27. The multilayer filter of claim 24 , which is pleated and includes a wire mesh supporting layer co-pleated with the filtration media.

28. A filter unit comprising filtration media according to claim 1 .

29. A method of making filtration media according to claim 1 comprising forming a wet laid sheet from a fibrous slurry comprised of the blend of synthetic non-fibrillated staple fibers and fibrillated cellulosic staple fibers, and drying the sheet to obtain the filtration media.

30. High efficiency and high capacity filtration media comprising a blend of:

synthetic non-fibrillated staple polyethylene terephthalate microfibers having an average fiber diameter of less than about 10 microns and an average fiber length of less than about 25 millimeters, and

fibrillated cellulosic staple fibers, wherein

the fibrillated cellulosic fibers are present in the media in an amount to achieve a multipass dust holding capacity of 10 mg/in 2 and greater, and a multipass filtration efficiency at 1.5 microns of greater than 50%, and wherein

the polyethylene terephthalate microfibers are the water-washed residue of water non-dispersible sulfopolyester fibers having a glass transition temperature (Tg) of at least 25° C., the sulfopolyester comprising (i) about 50 to about 96 mole % of one or more residues of isophthalic acid or terephthalic acid; (ii) about 4 to about 30 mole %, based on the total acid residues, of a residue of sodiosulfoisophthalic acid; (iii) one or more diol residues wherein at least 25 mole %, based on the total diol residues, is a poly(ethylene glycol) having a structure H—(OCH 2 —CH 2 ) n —OH , wherein n is an integer in the range of 2 to about 500; and (iv) 0 to about 20 mole %, based on the total repeating unites, of residues of a branching monomer having 3 or more hydroxyl, and/or carboxyl functional groups.