Lithorone color stripping??

We use two lithorones a s40p and a 28. We also use a mits f16. Only the Komori's are giving us a color stripping problem. Our fountain solution is the same for all three presses it comes from a RO filter and mixing station. All presses are using same blanket material, plates and roller material. Have tried three different ink venders with same results.
Found that we have to de-glaze the komori rollers a lot to prevent stripping where mitsy we just do regular roller maintenance. Any ideas would be appreciated.

 

we have stripping as in washing out when we get calicum in the rollers. sometimes we have to do a calicum wash once a day. thats on a ls640 and a ls540sp usally the magenta and sometimes cyan

 

We have an older lithrone 28 and a newer spica 29. we also have a slight stripping problem on the lithrone 28. we use calicumfix from bottcher and it work good. I've noticed the small copper rider roller in the ink train get pretty funky if we go too long without a calicum cleaning. the spica doens't have that problem.......

 

Do you have roller chillers? If so they might be set too low

We run our 40 @80 degrees, our 28 @ 75 degrees.

Good Luck

 

Try a vinegar water mix. Works for us as your last wash. 50/50 probably would work.

 

I had the same problem with our ls we tried all kinds of calcium rinses some would help for a day or two but what finally got ride of it was switching to a lower pigment Ink. Vanson Vs 3 or 5 work well the 5 dries better also k&e pertech run good but like to feed back to the metering roller. haven't had roller stripping since!!! we also rinse the rollers with salt crystal remover every couple of weeks. Just had a komori demenstrator tell use the best thing to use is lime away mixed 50/50. but I would say just switch ink!!

 

Sounds a lot like emulsification of the ink to me.
You're running an RO unit, that tells me your incoming water supply has issues, perhaps with high calcium but a unit like that is designed to 'filter' these out to a large degree.
Bear in mind that Komori's run solid copper pipe 'steels' - they're not plated. So I'd expect the ink receptivity to be very good. Check damps are not too high, check alcohol is around 5-8% and if you have a conductivity meter aim for around 1650 at 9 degrees C, ph around 5.5. We have run Komori's for years and never - repeat never, had stripping problems.

 

When I ran a 28 inch lithrone. We would have long runs using 26 inch paper and the ends of the rollers sometimes have problems. I think this is due to the water on the edge of the plate getting in the ink and then working its way into the rollers. The gum/etch and whatever.
Bottcher made this cleaner that worked pretty good when we had this problem.
It wasn't the febo clean. it was a liquid cream color stuff.

 

i was getting this problem also and came across this site!.took advice of richardk and problem seems to be gone .i had to bring my fount up to 7% to
achieve 1650 conductivity . thanks richardk.

 

Glad to hear you cured it. I hear Dublin serves nice cold Guinness - sorry subtlety is not one of my best points!

 

yes nice and cold, no need to check conductivity but do watch for stripping after a few too many!!.

 

roller's chiller 80 c? is that will cause all your units cover get dirty with ink because roller too hot

 

i don't have roller chillers so a high conductivity seems to help,also reducing the tack in the ink and keeping water as low as possible.

 

how if there is no conductivity meter?any guide or method to achieve proper conductivity value

 

no magic solution! had to buy one ,you can get one that will also give you the ph and temp. of water among other things.

 

update got new ink and it fixed the problem

 

is this stripping or what(in the red box)? our LS540 alway got this problem.after we clean the copper roller the problem gone

 

Looks like a combination of not enough ink and possible low spot on meter roller or forme dampener allowing more damp through at that point. Is this consistent, every sheet like this or intermittent? If intermittent check for oil/grease or even water dripping onto sheet before impression. I've seen condensation from the cold water pans drip onto sheets and cause this if the water pan is not insulated.

If the issue is consistent ie every sheet then...

Try this first, check all forme/dampener rollers for correct nip width (stripe) and adjust as necessary.

Problem still there?
Try this remove meter roller and exchange with one from another unit where you don't have the problem.

Problem still there?
Do same with forme dampener.

Roller stripping is rare on Komori - but you need to check all the above and quality of water supply/fount ph and conductivity as mentioned earlier in this thread.

 

when it happen we just running the machine idle for a few minutes and continue but after half pile the problem coming back. what is the correct nip width?some said 4mm or just try and error

 

Each roller will have a different nip width depending on its diameter and position and function in the dampener/inker system.

Have you not got a manual with roller diagram? Pointless me telling you what we run on our Lithrone since it's a 626, your 540 will have a different spec.

However, I've attached a pic of the diagram we use - maybe it will help.