Home > Products > Packaging , Printing & Paper > Printing Materials

POSITIVE PLATE INTRODUCTION

Our company’s PS plates have good plate life, high color contrast, and perfect dot reproduction abilities. In order to make the plate reached the best printing state, please use it under the following requirements.

1.        Exposure level

Aided by the Fuji Fifteen-steps step guide (recommended) or other compatible step guide, then under the correct developer concentration, temperature and the developing time, you should control the exposure level between the first two steps white and the third step shallow appearance. For example:

    OUR STANDARD

Positive Type (the first two steps clear)   FUJI fifteen-steps step guide

1.      Exposing time

The exposing time under 3000W lodine gallium lamp at 1 meter is about 75S. If the power of the lamp and the distance to the plate are different, please expose the plate abiding the data in the following table.

Before Exposing, please notice the efficiency of the vacuum-pumping, the film must be engaged with the PS plate without any cracks, or it will produce some halation, then the halation will influence the dot reproducing and decrease the plate life. So please keep the vacuum degree below 20Kpa.

The lamp distance to the plate must be longer than the diagonal line, and the lamp aligns to the plate positively. Or it will produce the halation and the exposure stage of plate will be non-homogeneous.

When the lodine gallium have been used for a long period, because of the ageing processing, you should notice to elongate the exposing time. When the exposing time is 20% longer than the normal exposing time, so as not to influence the working efficiency, you should consider to replace the lodine gallium lamp.

1.        Developing

       Developer: Fuji DP-4 developer or our company’s ARFA-Ⅱ developer

     Temperature: 25±1℃      Time of Developing: 30+/-10s

The developer’s dilution ratio:

             Automatic plate processor:  1:6

             Manual plate processor: 1:10

 Notes: Our PS plates required weak alkalinity developing; the developer’s concentration, temperature and the developing time should be paid much attention, or it will decrease the run length and the printing efficiency. On the developer or developing powder which are produced by other companies, please use it under the condition they required to achieve our standard.

1.        Correction

      Please use the image remover to wipe off the unwanted stains. And be sure not to damage the image. When the remover remains on plate for 45S, wipe off it with a piece of soft cloth, then wash it clear by water. Or it will be easily to be dusted.

1.          Gumming

   The gum must be diluted under the manufacturer’s requirements, and the layer should be well-distributed. If the layer is too thin, it will be easy to be dusted and be scratched; if the layer is too thick, the plate is not easy to get the ink, and the text is easy to lose. And if you gum the plate automatically, please control the dry temperature at 60℃.

1.          Baking

Baking temperature(Recommended): 230—250℃

   Baking time: 6—8 minutes

   After baking, please cool the plate naturally, don’t cool it by wind or water, or it would be distorted.

1.          Storage

Before exposing: The plates should be stored in the cool (10—30℃), dark and dry place.

After exposing:  To avoid the light, and storing under the safety yellow light.

1.          The reason of problems may happen and solutions