process and apparatus for improving web pinning and uniformity in a fibrous web forming operation . the improvements are achieved by imposing an auxiliary electrostatic field above the fibrous web as it is pinned along a moving collection surface . an auxiliary electrostatic field enhancing plate is positioned above the web and collection surface and downstream of the laydown position where the web initially is deposited on the collection surface . the plate enhances the electrostatic field in the region above the collection surface and thereby increases the web pinning forces . when the invention is applied to a flash - spinning process where trifluorochloromethane is used as the fluid medium , an auxiliary electrostatic field of between about 2 and 80 kv / cm , preferably between about 10 and 60 kv / cm , is applied by the plate .