| abstract |
An imaging element (15, 122) comprising on a lithographic base at least one radiation sensitive or heat-sensitive layer composition, is image-wise exposed to radiation or heat. The composition is such that when exposed and developed, a lithographic surface is formed. The exposed imaging element is then passed through a closed treatment cell (26, 64, 66) in a processing apparatus in which the imaging element is brought into contact with a single developing fluid (44, 124). The closed treatment cell (26; 64, 66) comprises a housing (24; 114) having an entrance (28; 116) and an exit (30; 118) each closed by a path-defining roller (32; 128) in contact with a reaction surface (33; 130) to form a nip (34; 136) therebetween, through which the plate path (36; 72) extends. Sealing means (38; 138, 139) seal each path-defining roller (32; 128) to the housing. Evaporation, oxidation and carbonization of the treatment liquid is significantly reduced and quality control of the plate is possible before mounting on a printing machine. |