Abstract: A doctor blade structural support has the form of a hollow structural member of roughly triangular cross-section, one side of the triangular cross-section being substantially tangent to the surface of the dryer roll. A quantity of water is disposed within the hollow structural member and resides on the inside surface of the structural member adjacent to the heated dryer roll surface. The interior of the doctor support structure is sealed from the atmosphere and is evacuated so that the interior of the structure contains only water and water vapor. Heat radiating from the dryer roll surface to the doctor support structure causes water disposed on the inside surface adjacent to the dryer roll to evaporate, thus raising the internal vapor pressure in the sealed interior of the doctor support structure. The water vapor continuously condenses on the inside surfaces of the support structure which are not exposed to radiant heating from the dryer roll.

Abstract: A guide roll apparatus is disclosed for guiding a contiguous web and web-supporting felt through a drying section of a paper machine. The apparatus includes a rotatable guide roll having an outer cylindrical surface defining a first and a second edge portion and a central portion disposed between the edge portions. The first edge portion defines a first plurality of air flow channels such that in use of the apparatus, when the web and felt are guided around the rotatable guide roll, air entrapped between the first edge portion and the felt wrapped around the first edge portion is permitted to flow through the first plurality of channels away from the felt so that fluttering of the web during guidance around the first edge portion is inhibited.

Abstract: In a calendering apparatus for hot-calendering a paper web, the apparatus includes a rotatable calendering roll defining a smooth calendering surface. A backing roll rotatably cooperates with the calendering roll for defining therebetween a calendering nip for the passage therethrough of the web. An induction heater is disposed in close proximity to the calendering surface nip for inducing eddy currents within the calendering roll such that the calendering roll is heated. A blow box is disposed in close proximity to the calendering surface and between the heater and the nip. The blow box defines a plurality of compartments which are disposed in a cross-machine direction. Each of the compartments selectively blows a current of cooling air against the calendering surface for controlling the temperature of the calendering surface so that the temperature of the calendering surface adjacent to the nip is controlled in a cross-machine direction.