positive ps plate

 positive ps plate

 positive ps plate exposure time is 48±10pulses, about 30seconds;(3kw iodine-gallium lamp, lamp distance:1.2meters). The exposure time is mensurated under standard voltage,standard lamp-house, vacuum pump air pressure over 0.08Mpa and use monolayer film. Because of different exposure equipments and different film types, the exposure time will be different in practice. Please get out the proper exposure time base on your own conditions.

   If use 13steps Gray Scale ( or UGRA PCW82) to measure the exposure time. The best exposure time of color printing is the time when the gray scale's second degree clean and the third degree slightly appear. The lines and the letters draft's best exposure time is the time when the gray scale's third degree clean and the fourth degree slightly appear. Please keep the films and exposure equipment clean, and make sure that the vacuum pump air pressure is over 0.08Mpa.

2. Developing

       The developing chemicals are recommended to get the most excellent effect.

   Developing powder: just one pack of developing powder could make 12-14L developer. The developing powder is mixed by many chemicals, so you should use all pack at one time, do not divide into several times.

   Dveloper: developer to water=1:6-1:8, please pressurize the rest developer in case or it will be ineffective.

   Developing Temperature: 22-25^oC

   Developing Time: 30seconds

   Do use clean water to wash both sides of the plate after developing till it has no soapy feeling.

3. Retouching, Gumming Up, Baking

     You could use the retouching brush, retouching liquid, retouching creamto remove the useless dots and lines after washing, then use clear water to wash the plate again after few seconds. gumming up could increase the hydrophilic ability and combine ink ability of the PS pressrun greatly. Baking Temperature:220^oC-240^oC. Baking will increase the particular conditions please read the illustration of your own chemicals and equipments.

4. Printing and Storage

        Recommended printing workshop temperature:   20^oC-25^oC

        Recommended printing worshop hunidity:           50-70%

        Recommended printing storage condition: Temperature 10^oC-30^oC

                                                                      Humidity:below65%

        The carton should be placed away from the wall and the ground over 15cm.

        Please open the carton under yellow light.The rest plates should be kept airtightly in the original carton.