Abstract: This invention is an improved applicator for coatings. It is particularly useful for applying hot-melt adhesives in the manufacture of corrugated board. The applicator consists of an apertured manifold from which adhesive flows in parallel ribbons onto a transfer roll. This, in turn, prints it on the tips of the flutes at the single facer or double backer. The manifold is center fed and is equipped with motor-driven, axially adjustable pistons to adjust the width of adhesive spread to the width of surface being coated or bonded. An air purge system operating from within the pistons effectively removes any residual material from the orifices when the pistons are advanced toward the center of the manifold. This prevents plugging from adhesives setting up in the unused orifices. The purge system can also be used to clear orifices that become plugged during operation or to completely remove all adhesive from the manifold.