Patent ID: 7501085

Claim:
A method of making a nonwoven web from a liquid material, comprising: establishing a first and second flow of the liquid material; changing the rheology of the liquid material in the first and second flows, the changed rheology of the second flow differing from the changed rheology of the first flow by an amount sufficient to produce a phase separation between the liquid material in the first and second flows when combined, wherein the liquid materials of the first and second flows are chemically identical both before and after changing rheology; combining the first flow of the liquid material with the changed rheology and the second flow of the liquid material with the changed rheology to form a plurality of meltblown fibers each having a length, a first cross-sectional region formed of the liquid material from the first flow, and a second cross-sectional region formed of the liquid material from the second flow, the first and second cross-sectional regions extending along the length of each fiber; separating the first cross-sectional region from the second cross-sectional region along the length of at least a majority of the meltblown fibers to form a plurality of nanofibers; and collecting the nanofibers to form the nonwoven web.