Plasma treated porous film

An open-celled, porous film layer includes voids. These voids have openings extending between adjacent voids such that paths exist so that liquids and/or vapors can traverse from one side of the film layer to the other. The layer may be in the form of a monolayer film or in the form of a multilayer film having the above-mentioned porous layer as a surface layer. The polymeric matrix of the porous film layer may be a polyolefin, such as polypropylene or high density polyethylene (HDPE). Such polyolefins are inherently hydrophobic. The water absorbency of open-celled polymeric films is improved by means of plasma treatment, whereby plasma is drawn into the pores of the film to make this pore space more hydrophilic.