Abstract:
A lithographic printing sleeve for mounting on a cylinder in a printing press is provided. The lithographic printing sleeve includes a tubular base layer for contacting and surrounding an outer circumference of the cylinder, a permanent tubular hydrophilic layer on an outer surface of the tubular base layer and a temporary hydrophobic layer on an outer surface of the tubular hydrophilic layer. A variable cutoff printing press is also provided.
Abstract:
Banks, as well as a plurality of recess-shaped cells defined by the banks, are provided in an image section formed in a gravure printing plate. A projecting portion is provided in each of the cells so as to protrude from a part of the base surface of that cell. The projecting portions are in positions distanced from the banks. Like the banks, the projecting portions can serve as starting points for the transfer of a printing paste. Accordingly, printing paste that would, in the case where the projecting portions are not provided, remain in the bases of the cells is transferred to the printing target material via the projecting portions, which increases the transfer efficiency. As a result, a paste film that is smooth and has the required thickness can be printed.
Abstract:
Banks, as well as a plurality of substantially recess-shaped cells defined by the banks, are provided in an image section formed in a gravure printing plate. Each of edge cells located along an outer edge of the image section is provided with a projecting portion that projects from a part of a base surface of that edge cell, and each projecting portion is distanced from the banks and located closer to the outer edge than the center of the corresponding edge cell. Preferably, the projecting portions and the banks that face the outer edge are positioned at a predetermined interval from the outer edge, and substantially frame-shaped recess portions that extend continuously along the outer edge are provided in the image section.
Abstract:
The present invention describes a method for manufacturing rotogravure cylinders with a cylinder base made of aluminum. The method involves the coating of the cylinder surface with high velocity spraying, the copper plating in an appropriate solution, the engraving of the cylinder, and the hardening of the cylinder by chromium plating. The spraying process is accomplished by High-Velocity Air-Fuel or High-Velocity Oxygen-Fuel thermal spraying which leads to less surface porosity, better adhesion of the copper substrate and better dimensional accuracy. The advantage of this method is the elimination of the surface roughening process and the elimination of the preplating process. In addition, the end plates are manufactured partly from aluminum and partly from steel which further reduces the total weight of the cylinder. The elimination of these processes reduces the weight of the cylinder and the overall manufacturing time considerably.