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A nonwoven web useful as a filter medium includes a plurality of bicomponent multilobal fibers including a higher melting polymer component, a lower melting polymer component, and an interface between the polymer components. The fibers are bonded together at points of contact including the lower mel

A nonwoven web useful as a filter medium includes a plurality of bicomponent multilobal fibers including a higher melting polymer component, a lower melting polymer component, and an interface between the polymer components. The fibers are bonded together at points of contact including the lower melting polymer components, to provide a coherent filter medium. The multilobal fibers include raised lobal regions and depressed regions between the lobes which catch, trap or ensnare particulate matter that is being filtered from a gaseous or liquid medium. The multilobal fibers may be electrecized to provide electrostatic attraction between the fibers and the particles.

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1. A nonwoven web, comprising:a plurality of side-by-side bicomponent multilobal fibers including a higher melting polymer component on a first side, a lower melting polymer component on a second side, an interface between the higher and lower melting polymer components, and a fiber denier of 0.5-10

1. A nonwoven web, comprising:a plurality of side-by-side bicomponent multilobal fibers including a higher melting polymer component on a first side, a lower melting polymer component on a second side, an interface between the higher and lower melting polymer components, and a fiber denier of 0.5-10;each of the multilobal fibers including a raised lobal region on the first side and a rounded region on the second side, the raised lobal region including at least one pair of raised lobes and a depressed region between each pair of raised lobes, the rounded region being depressed relative to the raised lobes;wherein each raised lobe consists of a radially projecting portion; anda plurality of round fibers having a fiber denier of 0.5-10. 2. The nonwoven web of claim 1, wherein the higher melting component is selected from the group consisting of high density polyethylene, polypropylene, propylene-ethylene copolymers containing less than 10% ethylene, and combinations thereof, and the lower melting component is selected from the group consisting of low density polyethylene, linear low density polyethylene, propylene-ethylene copolymers having 10% or more ethylene, and combinations thereof. 3. The nonwoven web of claim 1, wherein the higher melting component comprises polypropylene and the lower melting component comprises polyethylene. 4. The nonwoven web of claim 1, wherein the rounded region comprises one or more rounded lobes region is formed by heating the lower melting component. 5. The nonwoven web of claim 1, wherein the multilobal fibers comprise pentalobal fibers. 6. The nonwoven web of claim 1, wherein the multilobal fibers comprise about 10-90% by weight of the higher melting polymer component and about 10-90% by weight of the lower melting polymer component. 7. The nonwoven web of claim 1, wherein the multilobal fibers comprise about 40-80% by weight of the higher melting polymer component and about 20-60% by weight of the lower melting polymer component. 8. The nonwoven web of claim 1, wherein the multilobal fibers comprise about 50-75% by weight of the higher melting polymer component and about 25-50% by weight of the lower melting polymer component. 9. A filter comprising the nonwoven web of claim 1. 10. A nonwoven web, comprising:a plurality of side-by-side bicomponent pentalobal fibers including a higher melting polymer component on a first side, a lower melting polymer component on a second side, an interface between the higher and lower melting polymer components and a fiber denier of 0.5-10;each of the pentalobal fibers including a plurality of radially projecting lobes on the first side and a rounded region on the second side, the rounded region including one or more lobes depressed relative to the lobes on the first side and comprising the lower melting component; anda plurality of round fibers having a fiber denier of 0.5-10. 11. The nonwoven web of claim 10, wherein the higher melting component comprises polypropylene and the lower melting component comprises polyethylene. 12. The nonwoven web of claim 10, wherein the multilobal fibers comprise about 10-90% by weight of the higher melting polymer component and about 10-90% by weight of the lower melting polymer component. 13. The nonwoven web of claim 10, wherein the multilobal fibers comprise about 40-80% by weight of the higher melting polymer component and about 20-60% by weight of the lower melting polymer component. 14. The nonwoven web of claim 10, wherein the multilobal fibers comprise about 50-75% by weight of the higher melting polymer component and about 25-50% by weight of the lower melting polymer component. 15. The nonwoven web of claim 10, wherein the multilobal fibers are electrecized. 16. A filter comprising the nonwoven web of claim 10. 17. A nonwoven web, comprising:a plurality of side-by-side bicomponent multilobal fibers including a higher melting polymer component on a first side, a lower melting polymer component on a second side, an i nterface between the higher and lower melting polymer components and a fiber denier of 0.5-10;each of the multilobal fibers including a plurality of raised lobes on the first side and one or more rounded lobes on the second side depressed relative to the raised lobes;wherein each raised lobe includes a proximal end and a distal end which is no wider than the proximal end; anda plurality of round fibers having a fiber denier of 0.5-10. 18. The nonwoven web of claim 17, wherein the higher melting component comprises polypropylene and the lower melting component comprises polyethylene. 19. A filter comprising the nonwoven web of claim 17.