Light shades in non printing areas when using IPA free fountain solution

[amomtaz93]

I have a problem using IPA free fountain solution in sheet fed printers . In details i noticed light shades arround fine details like small fonts in non printing areas when using IPA free fountain solution speacially in black and magenta inks ,these shades some times can not noticed without usin a magnifying glass .So can anyone help me to solve that as it is important to keep using that fountain because of its high productivity and meeting environment condition.....

Thanks'
Ahmed

 

[Cornishpastythighs]

well heres my 2 pence worth. When you switch to a alcohol free fountain solution you may have to pay more attention to your press settings and maintenance.
Do you have a durometer guage to check your rollers hardness,
are you using a conductivity meter to measure/maintain your fountain solution doseage and are you controlling the temperature
Have you checked all your inking roller/dampening roller settings and packed your plates/blankets to spec.
Are your roller temperatures at manufacurers specs
Just some things you may have to do when you eliminate alcohol from your font,
many others will offer suggestions I'm sure

 

[turbotom1052]

Should also be noted that in addition to running the correct, and clean press chemistry, it is also of importance that the plate processor is set up and maintained properly. Ive seen the very problem you described traced back to a failure to keep pate processors clean, and replenished as per manufacturers recommendations.

 

[maxon]

Printing with zero alcohol is more difficult. Follow the above posts, if still having problems try adding 2 percent IPA and run a test print again, this essentially rules out the plate if toning goes away.
Background toning on plate in non-printing areas coming from residue coating or polymer re-deposit ; dirty rollers, too low replenish rates, or bad plate rinse can also be checked using the so-called acetone test - put one droplet on a non-printing area on plate, let it evporate, see if it leaves a fine bluish circle.