The present invention is directed to a method of forming nonwoven webs
comprising coated fibers. The method of forming the nonwoven web
generally comprises the steps of forming fibers from a melt fibrillation
process, forming at least one fluid stream containing a coating
substance, applying the coating substance onto the surface of the fiber,
and depositing the coated fibers on a surface to form a web. Typically,
the fibers are coated in flight. Preferably, the melt fibrillation
process to form the fibers is a melt film fibrillation process. A melt
film fibrillation process generally includes the steps of providing a
polymeric melt, utilizing a central fluid stream to form an elongated
hollow polymeric film tube, and using air to form multiple nanofibers
from the hollow tube. The nonwoven web may comprise a layer having a
significant number of nanofibers with diameters less than one micron. The
layer may comprise two or more pluralities of fiber diameter
distributions wherein at least one plurality has an average fiber
diameter of less than about one micron.