Abstract: An apparatus for producing a corrugated sheet from a web of deformable material, for use in cooling towers and the like, includes an endless conveyor which is adapted to move along a predetermined path of travel and on which are mounted a plurality of web molding trays. The trays have a plurality of corrugations formed therein extending generally transversely of the path of travel and means are provided for selectively locking the trays on the conveyor with the corrugations located at predetermined acute angles with respect to the path of travel of the conveyor so that the angle of the corrugations formed in the web can be varied. An air knife arrangement is provided for urging the web against the corrugations in the trays to form the corrugations in the web.