Abstract: The present invention relates to a novel method and apparatus for cleaning off the ink sediment and paper powder and the like which adhere to a cylinder such as a blanket cylinder in a printing machine, without using any cleaning solution. A brush roll rotated by an independent rotational driving source is brought into contact with a blanket cylinder during printing. The brush roll has many brush fibers which are planted in the outer periphery thereof and which are bent at the ends thereof so as to have a combing function. This is realized by bending the brush fibers in zigzags. It is preferable that the rotational directions of the blanket cylinder and the printing cylinder are opposite to each other, and the relative rotational speed is set to 5 to 12 m/s. The dry brush roll is surrounded by a casing in which a scraper for removing dust from the brush fibers and a dust collecting portion are provided, or to which negative pressure function means is connected so that the dust can be easily removed.

Abstract: A rotary press is operated slowly while paper is fed to the rotary press. A washing liquid is applied to the printing paper throughout substantially its entire width to wet the printing paper, and a plurality of guide rollers that are in contact with the travelling paper on the paper discharge side with respect to a printing portion are rotated at a peripheral speed different from that of the travelling paper so that contamination of the guide rollers is wiped off by the travelling paper. The washing apparatus of the invention has a plurality of guide roller driving devices which can drive and rotate the guide rollers at a peripheral speed different from that of the travelling paper.