Aqueous Coating leaking

Hi, Running a 2007 model Speedmaster CD74 6 colour plus coating Tresu chamber blade system.
Lately we have been having major problems with the aqueous coating running ( from what I can see ) over the end rubbers. It builds up between the analox roller and the rubbers causing splashes onto the coating blanket and impression cylinder bearers, and when you are running at 14000 +, it leaves a hell of a mess to clean up !!!.
Have had engineers, demonstrators look at it. We have checked and reset pressures, we have tried everything. Running steel blades both top and bottom, run steel top and plastic bottom; tried different angle cuts of the blade ends at different positions into the end rubbers. Only thing I can think of now is the rams that drop the chamber on are not powerful enough ?
Anybody else had problems like this or can maybe help would be appreciated.

 

Have you tried a different type of end rubbers ?

 

The new end rubbers seem to be working okay, Ah mate.

 

Hi mr heidelberg and tc rex, thanks for the replies. Well this has been a mission. Yes, it turned out the end rubbers were the culprit. We got someone in the end that knew what they were doing; reset all settings properly and produced some different end rubbers. Long story, but the git that was meant to know what he was doing didn't know what he was doing and lied through his back teeth. All good now though; unit has been in for 72 hours with no end leaks what so ever !!!

 

what end rubbers are you using we have the exact same prob on are cd.

 

Hi jmt,

They are Tresu white end rubbers. Heidelberg part number is C6.043.252.

 

ty tc.

 

can you please send me the part # of the seals that solved the problem

e-mail would be good
info@israel-biz.com

 

Hi Geon Printer Auck, Geon Wgtn here. We had some leakage on our 2006 cd 74 during first 3-4 months of use, We (against HB's advice) added a an extra metal clip to the outside of seal to act as a packer and give more space so the buildup didn't just end up at edge of Anilox, This has worked very well for us for the last 3 years. The seals only last a week as they do now run right on edge of cells but stopped any leakage. our big problem is leaking from bottom of unit we have plastic lower blade and HB reckon ours is the only dribbler(i doubt this very much) does yours dribble and need a nightly wash? Geon Napier can leave their one in for a week!
Good to see others in the group with a greater interest than just turning up to bash button's interesting that the press rooms never have any contact with each other we could prob help each other more than HB gits alot of the time..

 

Hey DWF, So you are saying you place a metal clip on the end, then an end rubber, then another metal clip, sounds good, I'll try that when I set up. Do you smear grease around the end rubber prior to placing them in the chamber ?. Tell HB your bottom blade isnt the only dribbler !. 'This isn't too bad though, as it only goes into the trough - I just get annoyed when it's all over my cylinder bearers, however, seems to be much better with the new end rubbers.

 

i was also wondering what psi is you chamber blade set at .The book says 2.0 but here they set it up to run a 4.0 .wouln't to much pressure wear the roller out faster.

 

2.0 is the correct pressure. I think the 4.0 is a little high and will probably prematurely wear out the Anilox roller over a long period of time......

 

Hi, Yes thats how we do the clips but we don't use any grease. We start our pressure at 1.0 with new blades and increase durning the week to about 2.0 we change blades every week. Have a great weekend..

 

guys , the rubber seal must be in good contact with the Anilox roller = if you take the old seal out and the part between the blades is not worn by the roller = you have the wrong pressure or the wrong seal.
seals come in sizes. if they do not sel - take a higher one like 30.
the clear Tresu seals are for water base and the black one for UV but can take water base too.
seals only work on the edge = if you have a leak in the center , check if your blade is 100% leveled with the chamber base - if you have some dry coating under the blade it can damage the seal and leak
GL

 

I don't use the metal clip to keep the rubber end piece in place at all. We do a complete wash up ,taking the chamber off and completely clean it everynight. On friday night we change the metal blades,top and bottom . As far as the rubber ends go, I just push them to the outside as far as they will go and then run a bead of silicone all around the outsde edge . This holds them in place without even using the clip and also prevents leakage.

Rod

 

Hi everyone. Does the printing area decrease after one night when 2 color had printed? If does, how to fix it ?

 

As youve already found out that white/clear end rubber seals are the correct ones for water based/conventional coatings. Although for us its common practice to give the clear rubbers a smear of grease to help sealing. They also produce black rubbers which are dedicated for Uv coatings, ( no greasing )
Also leaving the top blade angle uncut does help in some circumstances, if buildup/drying still occurs at the ends you could add 4% of water to a 25L to increase drying time.
Also make sure the blades are installed the correct side down. If set correctly steel blades and seals last weeks in both cases.
Dont not allow the unit to slap against the roller on installation and set the unit pressure to 3
Wash/strip conventional fully every night. Uv when the blades/seals need changing which can be months

 

The problem was with a batch of black seals, they had 3 definite circles on the side, the problem should now have disappeared. The chamber setting does need to be checked, take out the seals and put the chamber in contact with the roller and then turn off the airpressure. Check the contact of the botttom blade and adjust until the bottom blade touches. Normally the top blades is too strong and bends slightly opening a small gap between blade and seal. Use steel top blade and plastic bottom to stop Reverse doctoring (drips under the chamber). When setting up empty the feeder to shutoff sheet guide compressors, they can dryout the anilox roller and create drips.

 

THE CHAMBER DOCTOR. Hi There was a problem with the black seals check if they have 3 distinct circles on the side, do not use these. Best results to stop reverse doctoring (drips under chamber and end seals bunging up) is to use steel blade top (no cuts) bottom blade plastic ( angle cut 5mm from edge of seal down to clamp) If the plastic ripples its down to the eccentric tube. Try instead a steel blade 45mm x 0.1mm. The problem you have is reverse doctoring by the bottom. The problem is worse with higher volume anilox rollers and machine speeds above 12500. The chamber setting does need checking. The top blade is probably making contact before the bottom one. Air pressure 2 to 2.5 depending on pump speed and viscosity of coating. Make sure the seals are actually running on the non-engraved area of the anilox, clip -seal - clip on a 74 is wrong. You need end stops putting in the chamber. iF they are running on the engraving you will always have problems. Check out Bryan Wood Machinery(Auckland) sent blades and seals for same problems on a Komori. Check you roller spec aswell lines per inch affects 74's. A bit of a long answer bit it can be a big problem

 

how to tell what size seals we have now.we are using the clear ones.