White dots on solids after 500 pages.

[OkiTech]

Hi everyone, happy upcoming holidays. I am running Ryobi 3200 PFA and after 400 - 500 pages I get lots of tiny white dots over solids.
Here what I know: they are not on the plate.
Blankets are Brand new OEM.
Changing fount. solution does not do anything - changed from AB Dick pink solution to VARN.
Ink-changed 3 types of ink - no difference.
Changed brand of paper, also no difference.
I am honestly running out of idias, If anyone has any experience or knowledge about this, please let me know. Thank you.

 

[swifty]

do you use a lot of powder? is the powder coming out ok ? also give the delivery area a good cleaning,What kind of stock are you running ?I have notied an increase in paper dust with just about every stock.,after a run can you see a lot of paper dust on the feeder table? if yes either fan out the paper realy good or run the stock thru without printing,clean up the press and get rid of the dust then run the job.

 

[Printer Mike]

This may sound silly, but check for oil specks getting on stock.....

 

[OkiTech]

Hi, thank for your input guys. I am running regular 20lb white 11x17 paper. No powder. Yes there is some paper dust on paper path but show me the press the has none , I mean I clean it from time to time, let me clean it well and run it again. Thank again.

 

[OkiTech]

Mr. Printer Mike, do you mean oil carried by air in separation area.

 

[realaqu]

try run dry paper through the press, say 1000 sheets and print on them to see any difference, that gonna tell the problem is from your paper or not, and try to reduce the ink tack and increase ink feed and water feed, this has been said on GATF trouble guide

if that works, you d better think get a different brand paper. the industry change the way to make paper nowdays.

Hi, thank for your input guys. I am running regular 20lb white 11x17 paper. No powder. Yes there is some paper dust on paper path but show me the press the has none , I mean I clean it from time to time, let me clean it well and run it again. Thank again.

 

[Printer Mike]

Mr. Printer Mike, do you mean oil carried by air in separation area.

Yes, could be. When you say "dots", that makes me think of tiny oil particles that could be invisible on the blanket and/or paper. I have seen it before.

For some reason the oil spots may take a while to show up. (It could take 500impressions worth of time for the oil to get warm and move to an exit point).

Just a guess.....

 

[FFR428]

The vac pump can spritz oil onto the sheets thru the blowers. You can put a cotton pad flat on the bottom of the filter jar to help catch excess oil. Regular changing and cleaning of the filters and jars can reduce this. Minimum blower settings can help too. If you've changes inks, stocks etc...with no change it could be blowing oil. Also check your side guides are not scraping the sheets which can cause excess paper dust.

You can also be throwing excess water onto the sheets from the damp system which can cause the same problem.

Reducing the ink tack can help if the problem continues. Too much tack can cause the paper to pick on solids on light weight uncoated sheets no matter what the paper brand is. Just the nature of the beast.

Flag some good samples for the client and let er rip!! You'll go nuts trying to make it perfect otherwise.

 

[swifty]

also if not poweder/vacume troubles maybe calcium deposits on the ends of the rollers,some febo clean and hot water will help clean it up

 

[tstruth]

If I was the pressman on this machine, and I have run this type of machine for many years I would pull the rollers including the forms and give them a good cleaning. Blanket wash and pumice powder. Be sure to install rollers correctly, use the other unit as a map. Be sure the ink is not to stiff, if it is order some with less tack. By the way, what type of plates do you use, poly or metal?

Tom

 

[Tahir khan]

lhi B T as you told you have white tiny spots on solid grounds , can you tell me about your dsign is solid have only one layer of ink or sporting color under the solid ground .if your machine is 2 color use 2nd impression to cover if it is 1 color reduce the tack of the ink . Use a little bit light shade with a little more ink to compencate the shade & try to use paper which have a good surface strength.