Filter element including a composite filter media

1. A filter element comprising a first end cap, a second end cap, and a composite filter media structure, the composite filter media structure comprising:

a base substrate comprising a nonwoven synthetic fabric formed from a plurality of bicomponent synthetic fibers with a spunbond process, said nonwoven synthetic fabric comprises a bond area of about 10% to about 14% of an area of said nonwoven fabric, said bond area pattern comprising a plurality of substantially parallel discontinuous lines of bond area, said base substrate having a minimum filtration efficiency of about 50%, measured in accordance with ASHRAE 52.2-1999 test procedure; and

a nanofiber layer deposited on one side of said base substrate by an by electro-blown spinning process, said nanofiber layer comprising a plurality of nanofibers, said composite filter media structure having a minimum filtration efficiency of about 75%, measured in accordance with ASHRAE 52.2-1999 test procedure,

said composite media structure further comprising a plurality of corrugations, said corrugations formed using opposing corrugating rollers at a temperature of about 90° C. to about 140° C.

2. A filter element in accordance with claim 1 wherein the plurality of bicomponent fibers comprise a core material and a sheath material, the sheath material having a lower melting point than the core material.

3. A filter element in accordance with claim 1 wherein said core of said synthetic bicomponent fibers comprise at least one of polyester fibers, polyamid fibers, polyolefin fibers, thermoplastic polyurethane fibers, polyetherimide fibers, polyphenyl ether fibers, polyphenylene sulfide fibers, polysulfone fibers, and aramid fibers.

4. A filter element in accordance with claim 1 wherein said nonwoven synthetic fabric comprises a basis weight of about 100 g/m 2 to about 300 g/m 2 .

5. A filter element in accordance with claim 1 wherein said bicomponent fibers comprise an average diameter of about 12 to about 18 microns.

6. A filter element in accordance with claim 1 wherein said plurality of nanofibers comprise an average diameter of about 500 nm or less, the nanofiber layer having a basis weight of about 0.6 g/m 2 to about 20 g/m 2 .

7. A filter element in accordance with claim 1 wherein said plurality of corrugations comprise a plurality of alternating peaks and valleys extending a length of the composite filter media.

8. A filter element in accordance with claim 1 wherein said plurality of corrugations comprise alternating up and down substantially V-shaped corrugations.

9. A filter element in accordance with claim 1 wherein said composite filter media structure comprises a corrugation pitch of about 3 to about 10 corrugations per inch and an effective depth of at least about 0.02 inch.

10. A filter element in accordance with claim 1 further comprising a plurality of pleats.

11. A filter element comprising a first end cap, a second end cap, and a composite filter media structure, the composite filter media structure comprising:

a base substrate comprising a nonwoven synthetic fabric formed from a plurality of bicomponent synthetic fibers with a spunbond process, said nonwoven synthetic fabric comprises a bond area of about 10% to about 14% of an area of said nonwoven fabric, said bond area pattern comprising a plurality of substantially parallel discontinuous lines of bond area, said base substrate having a minimum filtration efficiency of about 50%, measured in accordance with ASHRAE 52.2-1999 test procedure; and

a nanofiber layer deposited on one side of said base substrate by an by electro-blown spinning process, said nanofiber layer comprising a plurality of nanofibers, said composite filter media structure having a minimum filtration efficiency of about 75%, measured in accordance with ASHRAE 52.2-1999 test procedure,

said composite media structure further comprising an embossing pattern, said embossing pattern formed using opposing embossing rollers at a temperature of about 90° C. to about 140° C.

12. A filter element in accordance with claim 11 wherein the plurality of bicomponent fibers comprise a core material and a sheath material, the sheath material having a lower melting point than the core material.

13. A filter element in accordance with claim 11 wherein said core of said synthetic bicomponent fibers comprise at least one of polyester fibers, polyamid fibers, polyolefin fibers, thermoplastic polyurethane fibers, polyetherimide fibers, polyphenyl ether fibers, polyphenylene sulfide fibers, polysulfone fibers, and aramid fibers.

14. A filter element in accordance with claim 11 wherein said nonwoven synthetic fabric comprises a basis weight of about 100 g/m 2 to about 300 g/m 2 .

15. A filter element in accordance with claim 11 wherein said bicomponent fibers comprise an average diameter of about 12 to about 18 microns.

16. A filter element in accordance with claim 11 wherein said plurality of nanofibers comprise an average diameter of about 500 nm or less, the nanofiber layer having a basis weight of about 0.6 g/m 2 to about 20 g/m 2 .

17. A filter element in accordance with claim 11 wherein said embossing pattern comprises a plurality of pairs of a rib and a channel, the plurality of pairs spaced apart and arranged in staggered rows.

18. A filter element in accordance with claim 11 further comprising a plurality of pleats.