Vacuum assisted web drive for corrugator double backer

An apparatus for moving a double face corrugated paperboard web through a heating section of a double backer comprising:

• a web supporting conveyor belt positioned downstream of the heating section;
• means for driving said belt in the direction of web movement;
• a belt support structure under said belt including vacuum plenum means and a vacuum source operatively connected to said plenum means;
• openings in said belt providing vacuum air flow communication between a web contacting surface on said belt and said plenum means;
• a series of discrete raised support elements on said belt having flat surface portions defining said web contacting surface, said support elements defining therebetween a network of open channels;
• said openings extending through the belt and in communication with said channels;
• a gridwork of adjoining frame sections on said belt extending longitudinally and laterally thereover, the longitudinally extending frame sections defining a plurality of rows;
• each frame section defined by an enclosing rib having a flat outer surface coplanar with the flat surface portions of said raised support elements;
• and,
• said openings comprising laterally spaced lines of apertures extending along the belt, each line of apertures positioned to bisect a row of said frame sections.

A vacuum assisted conveyor apparatus for moving a web of material comprising:

• a continuous web transport belt underlying and supporting the web across its lateral width;
• means for driving said belt;
• said belt having flat surface portions on the upper belt surface defining a web contacting surface, said surface portions defining therebetween open channels;
• laterally spaced lines of longitudinally extending openings in said belt providing communication between the lower belt surface and said channels;
• a support structure underlying said belt and providing sliding support for the driven belt;
• said support structure including a series of parallel laterally spaced vacuum plenums defining belt support surfaces extending the length of the conveyor;
• longitudinal vacuum distribution means in each support surface connected to said vacuum source;
• one of said lines of belt openings aligned with each vacuum distribution means;
• a vacuum source operatively connected to said plenums to supply negative pressure to said channels;
• said plenums arranged in cooperating plenum pairs, each plenum in, a pair positioned on the opposite side of and equally spaced from the centerline of said belt with each of said pairs progressively more distant therefrom;
• and,
• control means for selectively connecting the vacuum source to only those of said plenum pairs over which the web centered on said centerline is traveling.