US Patent 7427434 Self-bonded corrugated fibrous web

A self-bonded corrugated web made from a primary pre-bonded web layer of thermoplastic fibers having a substantially uniform thickness. The primary pre-bonded web layer is arranged to form corrugations forming a corrugation pattern of parallel corrugation lines, which can be parallel to the longitudinal extension of the web. The corrugated web is heat- or melt-fusion bonded in regions forming a primary bonding pattern of a plurality of primary bonding pattern lines, which are arranged non-parallel to the corrugation lines and which intersect at least two of the corrugation lines, for stabilizing the corrugations.