Abstract: In a preferred embodiment of the present invention, a web of a corrugating medium is supplied to heated corrugating rolls to which a water mist carrying a solid lubricant as a release agent has been applied evenly over the roller, a first linerboard is glued to one side of the corrugated medium, a second linerboard is passed over a preheating roller to which a solid lubricant is applied via a water suspension sprayed on the preheating roller, the second linerboard is glued to the single faced corrugated board and the resulting double faced corrugated paperboard is passed over a hot plate section while subjected to pressure from a belt and weight roller assembly from above the hot plate.

Abstract: Improved method for corrugating paperboard, wherein a web of a corrugating medium is treated with a solid lubricant for a release agent and supplied to heated corrugating rolls to which a water mist has been applied evenly over the rolls. The web is shaped between the rolls by the application of pressure from the rolls and steam formed from the water spray. The availability of steam at the nip of the corrugating rolls provides improved flute formation and the solid lubricant allows the corrugated paperboard to release from the corrugating rolls without damage to the flutes. Standard corrugating equipment is enabled to operate at higher production rates and to accept lower quality paper for corrugating. Equipment is provided to maintain a supply of solid lubricant in a water suspension for application to the paperboard, preferably via a water spray directed on the corrugating rolls.