Abstract: A double backer for curing the web bonding adhesive and drying the corrugated paperboard web utilizes a web holddown apparatus for maintaining the web in intimate drying contact with the lower heating units which does not require the use of a driven holddown belt. The holddown is provided instead by a series of parallel, flexible, closely spaced strips suspended above the web in the heating section and extending in the direction of web travel. The length of the holddown strips in contact with the web may be selectively varied.

Abstract: A dryer system for drying a coating applied to a substrate includes a thermally conductive roll having a length and a peripheral surface for supporting the substrate, and a plurality of energy emitters disposed within the conductive roll along the length of the conductive roll. The plurality of energy emitters are controlled to selectively emit energy along the length of the conductive roll. The conductive roll is at least partially surrounded by at least one convection unit. The convection unit includes a blower assembly, a heater assembly and a vacuum passageway. The blower assembly includes an inlet and directs a current of air towards the substrate. The heater assembly heats the air being directed towards the substrate. The vacuum passageway extends between the substrate and the inlet of the blower assembly for returning the heated air to the blower assembly once the air has impinged upon the substrate.

Abstract: A roller apparatus (23) for use in the drying section of an apparatus for producing corrugated board comprises a tubular body operative to be received over a metal roller. The wall of the tubular body comprises an inner layer (24) of relatively hard polyurethane and an outer layer (25) of a deformable polyurethane. A spiral winding of yarn (26) is wrapped around the inner layer (24).