METHOD AND APPARATUS FOR TREATING PHOTOSENSITIVE LITHOGRAPHIC PRINTING PLATE

PURPOSE:To prevent deterioration of treating agent due to microorganism and contamination of a printed matter by developing a photosensitive lithographic printing plate by an automatic developing unit and then treating it with sterilized desensitizer or rinsing agent. CONSTITUTION:Washing water in a washing water tank 31 is fed under pressure by a pump 35a in a washing section B to be injected from a shower nozzle 32 to a surface of a photosensitive lithographic printing plate, and squeezed by a squeeze roller 11b to finish washing. Then, the plate is conveyed to a rinsing gum section C, and rinsing liquid or desensitizer is applied to its plate surface. During the operating, the gum liquid is sterilized by applying the rinsing liquid or the desensitizer to the plate surface. Residual bacteria of the sterilized gum are removed by a filter 37 before a pump 35b in a tube for circulating the sterilized gum liquid, and the gum liquid in which bacteria and fungi are extremely reduced is circulated to be used.