Abstract: At least one boundary control roll is disposed adjacent a moving web of paper or like material being imprinted with ink. The web of paper has opposing planar surfaces, and at least one such boundary control roll is positioned in transverse non-contacting proximity to a planar surface of said web and rotated counter to the direction of travel of the web. If multiple rolls are used, the rolls on opposing sides of the web should be coacting and counter-rotating. The boundary layer formed about the peripheral surface of each roll is adjustably positioned within the boundary layer on adhering to the moving web. By colliding the respective boundary layers, a zone of interference is created and the boundary layer of the web is significantly reduced in thickness. In this manner, the thickness of the hot solvent-laden boundary layer adhering to each side of the web is effectively reduced.

Abstract: The invention relates to a simple mechanical system to effect removal, reduction or change in composition of boundary layered atmosphere associated with web passage around a heat transfer roll. In effect, the purpose of the invention is to eliminate the layer of air between the web and the heat transfer roll, or to eliminate as much air as possible so that better and more intimate contact is achieved between the web and the heat transfer roll, or to change the pressure and composition of the atmosphere, thus assuring higher efficiency of heat transfer from the roll to the web. The mechanical structure can involve a squeeze roll positioned between the heat transfer roll, squeezing the boundary layer of air attached to the web out prior to web contact to the heat transfer roll. In addition, the squeeze roll could utilize some type of vacuum associated with it.