METHOD OF POSITIVE-TYPE PRESENSITIZED OFFSET MASTER PRODUCTION

摘要

The solution concerns the production method of the pre-sensitised offset printing plate of a positive type intended for production of printing forms by copying from positive copy patterns. The aluminium plate is roughened electrochemically, whereupon an oxide layer arises on its surface by anodic oxidation and its pores are filled in distilled water. The degree of filling is controlled by water temperature in the range between 60 and 90 degrees and treatment time in the interval between 1 and 10 minutes. Light-sensitive solution is applied on the so treated surface, whereupon it is dried at the temperature between 40 and 60 degrees C and heat-treated at the temperature between 80 and 100 degrees C for the duration of 5 to 15 minutes. The solution can be utilized in printing industry.