Cleaning & Degreasing is a very important step for the Production of a good engrave screen.
DEGREASING IS CARRIED OUT BY TWO METHODS
METHOD NO. :
Chromic acid is scrubbed for 10 – 15 – min on the Nicket Screen to be degreaaed and then the screen is hosed down with water. We do not recommend this process since it leaves an etching effect on Nickel Screen & Nickel Screen can not be used for more than 2 – 3 times. It also requires constant attention for properly carrying out the task.
METHOD NO. : 2
(APPLICATION FOR DEGREASER)
Degreaser is used in the ration 1:4 with water I.e if the tank capacity is 300 Kgs. Then 255 Kgs, Of water is poured into the tank first followed by 75 Kgs. Of DEGREASER.The screen is then immersed in the liquid for 10 min. & followed by through by washing with plenty of water & kept for drying in dust free atmosphere.
ADVANTAGES OF USING DEGREASER :
It reduces the excess use of of PHOTO EMULSION since it has the tendency to Penetrate through the nicket screen to the inner surface so that max Photoemulsion is coated on the outer surface.
It helps in reducing development time.
It will not damage screens.
Increase screen life & reuse potential.
Reduce the pin – holes problems to a very great extent