Nonwoven materials having controlled chemical gradients

摘要

A substrate including at least one anisotropic property in at least one of an X-, Y-, and Z-direction. The anisotropic property includes a predetermined gradient applied by a migration of electrostatically charged droplets. The anisotropic property can be applied as a fluid on the substrate formed as a film or web or laminate in which the substrate is located between two spaced apart electrodes for generating an electrostatic field. An electrostatic field is generated on each side of substrate and a fluid is introduced as droplets for application to the substrate into the electrostatic field on at least one side of the substrate, forming electrostatically charged droplets. The electrostatically charged droplets are directed based upon a predetermined pattern onto the at least one side of the substrate. In accordance with one embodiment, the electrode on the side opposite to the side on which the droplets are introduced is used to cause the droplets to migrate into the interior of the substrate.