komori l420 damp problems

Hi
we are having a problems with our damp when the machine is cold say first thing in the morning the damp is fine running at anything from 10 -15 but towards the end of the day we find ourselves constantly having to bring the damp up to sometimes 60-70 we then have problems with scumming one minute, then the plates washing out the next. We are constantly checking and adjusting the dampers throughout the day. We changed the metering rollers which seemed to solve the problem but only for a short time. I have ran various machines in my life including heidelberg cd 6col 102 with coaters and have never had so much trouble with damp any help with this problem will be appreciated
cheers
glenn

 

HI Glen,
I am a freelance komori Demonstrator based in the uk if you want to give me a ring feel free.
+44 (0) 161 408 6131/ +44 (0) 7828 271 734
email paul@professional-print-services.co.uk
http://www.professional-print-services.co.uk
or leave you no and i will phone you as i am working out of the country at the moment.

 

What's the temperature in the water circulator? We run @ 9 deg C

Are you running roller stripes as per manual?

How about your meter roller - we open up til we get 'heavy water' then shut til the roller goes matt then 2 clicks more.

What % alcohol you running at? Anything between 8 - 10% should be OK.

Any additives to the fount? Varn Supreme works for us

How clean are your reservoirs and sediment?

Basic stuff really, but needs to be eliminated. We're not that far from you (Derby) and the only issue we have is during the day we tend to come up about 10% -15% depending on ambient temperature.

Also I presume that the press is a Lithrone 20 so should be fitted with komorimatic and either royce or tecnotrans recirculator.

 

re damp

Hi Richard
Yes the press is a lithrone 20 and it is running a royce system with the temperature around 9 degrees. We are running with alcohol at around 8% but we have gone up to 12% before without much change in the problem, our fount is around 4% and were using combifix for hard water but we dont have any more any additives , would you suggest using the varn supreme if so at what percentage do you use. What does the varn supreme do? We tend to clean out the royce system every three weeks or so and the trays were done only last week.
Cheers and thanks for your help
Glenn
:

 

I Tend to agree with Richard, If i was there i would drop the water clean the chiller unit down(royce or tecnotrans) clean the troughs.Flush the system out a few times.
Now fill the system by hand (do not use the douser just in case faulty)
check damper settings, check that the plate damper is not on too hard if it is it will take the drive from the plate cylinder not dampers.check the metering rollers as Richard said .
try ph 4.5/5
alchol 6%-8%
conductivity 1100 (although these are my preferred settings i do understand they change from demonstrator to demonstrator printer to printer.

good luck
give me a call if you need too!!!

 

HI Glen,
Are you getting the problem more on one unit than the others ie. magenta
from what you are saying if your house keeping is that good( most places i go to seem to clean only when they get a problem) take a good look at the unit to make sure what you have got it set at you are actually getting.

good luck

 

Hi
Thanks for the response our housekeeping is pretty good we seem to think that their maybe a problem with our rollers we have to set them in the morning and then later on in the day, we also have a problem with foaming and we maybe using the wrong filters. What filters should we be using?
We set our rollers on the damp on 2mm stipes.
Any advice on who to use for roller recovering?
cheers
Glenn

 

Hi Glenn
I personally use bottcher for all my roller requirements they have them on the shelf and you just exchange stocks latter(01495 350300 STEVE LILL ) there is also R2R.You will be able to get filter bags from most places komori uk will hold them in there spares dept.Although i am not there to see your problem and you might very well need to replace your rollers if its happening on all decks it tends to point away from rollers and more to fount.
As you know once your rollers are set right they are set the only roller you then change is the metering roller as conditions change.
I am passing Monday on the way back from a job if you would like me to all in for free just give me a call 07828271734.
i do think it points away from it being just rollers

good luck
may see you monday

 

Hi Glenn - what do your rubber rollers look like when dry - are they velvety or smooth & shiny? If they're smooth & shiny then I'd side with KD and say they're probably worn. And KD is right Boettcher are the best roller recoverers.

The foaming is a 'pita' - we had it with Royce and our current Tecnotrans. There is a silicone antifoam additive (Litho Supplies) that works reasonably well - but I reckon it's air being introduced into the the return flow. Tell you what if anyone can crack that one they'd be well off!

 

Hi Paul

Thanks for your help it was good to talk to you on the phone today, look forward to seeing you after the move.

Once again thankyou
cheers
glenn

 

Hi Richard

The rollers actually look fine nice and matt looking. I know the rollers we have at the moment that we had re-covered came back with black rubber and i thought that the metering rollers are meant to blue, does this make any difference as long as the shaw hardness is correct?

Cheers

Glenn

 

Cheers Glenn,
Look forward to coming down to see you all like i said any problems in the meanwhile just give me a call.
Regards
Paul
(Komori Demonstrator)

 

Glenn,

I run a lithrone 420.
The damp rollers are kinda touchy. I had problems when I first started running this press. I was running a 628.

If you have decent rollers. Try a light setting between the metering roller and the chrome roller. Start with 2mm instead of 3mm. Also use 2 clicks for pan roller to metering. The basic setting for the other lithrones are 4 clicks.
Also when the press runs longer the rollers gets hot and the roller will swell up and your contacts between the rollers with get tighter a little.

 

Just reread this thread and thought I'd let you know about our shift away from IPA

2for1 fount replaces IPA (big cheer from the 'green' party) as well as the fount additive we used to use.

Results are very good, although we still have to lift damps up through the day.

Print quality is sharper, showing more detail in shadow areas, the severity of picture-framing on the impression cylinders is much reduced. I even reckon there is more gloss to the print.

A plus is the that it works out a tad less expensive than the IPA/Varn Supreme combination.

Vision Inks supply it in our area...07854 010960 Gerry Northfold

 

hey i have been having the same problems which are now driving me up the wall, we replaced the pan and form roller and gave the water system a good flush out but are still getting scumming on the near lay side only and lifting the water tends to wash out the ink on the rest of the plate but does get rid of the scumming its really a game of cat and mouse threw the day, did you find a solution to this problem???