METHOD AND APPARATUS FOR MAKING LETTERPRESS PRINTING PLATE* AND PRINTING PLATE MADE THEREBY

摘要

A process is provided for making a relief printing form which is at least partially cylindrical from a liquid photopolymerizable molding material. In accordance with the process, a molding material is spread over the internal surface of the cylindrical wall by centrifugal force and hardened in the desired places with ultraviolet light to form an image corresponding to a printing design. The nonhardened portions of the molding material are then removed. The cylindrical wall is a transparent cylindrical tube. An exchangeable image-bearing film is placed on the inside of the tube. Photopolymerizing radiation of the printing form material is effected during rotation of the transparent cylindrial tube. An exchangeable image-bearing film is placed on the inside of the tube. Photopolymerizing radiation of the printing form material is effected during rotation of the transparent cylinder by means of one or more radiation sources distributed around the circumference of the transparent cylinder. The rays act on the molding material via the wall of the transparent cylinder and the image-bearing film. The radiation for hardening the printing form takes place in a continuous operation following the application of the molding material to the cylindrical wall by centrifugal force.