The job of dampening form rollers is to take up the fountain solution uniformly from the transfer or metering roller, transfer it to the printing form and provide a good ink-fountain solution emulsion. When a dampening film is taken up by a dampening form roller, the film is stretched, as the dampening form rollers runs much faster than the metering roller. Here, it is important that part of the fountain solution is emulsified in the ink. Thin negative lines and structures in the image are kept free of ink by the fountain solution emulsified in the ink which is released, when the emulsion separates under the pressure of the plate roller.
In the dampening unit there are also rollers that receive the water and rollers that give the water to the printing plate. Accordingly, there may be two different dampening systems:
DAMPENING ROLLERS - AquaFloEx, AquaFlo Alcohol & Water Compatible
Alcohol Dampening Rollers
Alcohol Damping Roller supplies alcohol for printing objects in the Offset Printing Machine. It is having the mixture of alcohol and water in it, the percentage of alcohol and water varies for machine to machine and depends on the object to be printed. The alcohol roller is used naked or without cover. If the roller has converted from water to alcohol then the diameter should be increased.
Ideal compound for Dampening, Pan and Metering roller for IPA, IPA-reduced and IPA-free printing.
Suitable for Sheetfed & Webfed offset application.