Patent ID: 7399267

Claim:
A method for manufacturing corrugated cardboard, comprising: providing a core of fluted linerboard with elongate flutes having a series of convex apices; applying adhesive to the convex apices of the fluted linerboard; providing upper and lower sheets of linerboard to sandwich the core of fluted linerboard therebetween; applying a vacuum along a longitudinal edge of the fluted linerboard sandwiched by the upper and lower sheets of linerboard to reduce the pressure between the upper and lower sheets of linerboard to cause the upper and lower sheets of linerboard to be drawn into bonding contact with the core of fluted linerboard; and removing excess moisture from the fluted linerboard and upper and lower sheets of linerboard to dry out the corrugated cardboard as it is being manufactured by passing pre-heated hot air through the fluted linerboard.