Heidelberg dampening problem

[477sm]

We have a SM52 2/C press. Our problem is in the alcolor system. We have banding or tinting the last 4 inches across the blanket cylinder. We have completed all the usual suspects but not having much success.
Bottcher fountain solution s3002 @ 64 degrees 10% alcohol
Bottcher rollers 6 months old
Have reset rollers many times, less stripe seems to help
Good settings to vibrators

 

[plotter]

i know you said new rollers, but have you tried turning them around to see if it happens on the other side, if so you know that 1 or 2 of the new rollers are not perfect. ive had it before, and the new rollers were the last thing i thought of

 

[mrheidelberg]

i know you said new rollers, but have you tried turning them around to see if it happens on the other side

What do you mean by saying turn them round, the OP said he had an issue on the last 4 inches ACROSS the blanket.

 

[477sm]

This problem is not one side or the other it is across the entire cylinder at the tail of both units.
Thanks for your thoughts

 

[477sm]

mrheidelberg obviously you have much experience with install startups as well as problem solving. Can you recommend a fountain etch in the states with alcohol and also your opinion about excluding alcohol and a solution to use for this process also.
Thanks
477sm

 

[Chris@ipswich]

Hi, ive run 52s for years and experienced this also, do you have Vario?
Try dampening settings also.

 

[477sm]

No I do not have Vario. I am new to Heidelberg presses and my assumption is that this is an Alcolor system.

 

[paul j]

inking up or misting on blanket

Any lateral play in the form rollers can cause this problem. Have you checked that any of the form roller occilators are open, the one you set with the t bar, or have you shimmed out the form rollers so they are snug in the journals, remove bearings and add the shims but dont force them into the journals as the rollers may not drop to the plate.

 

[Smck89]

I'm also having dampening problems on an SM 52 5 colour. I'm having to put the damp % up to around 30 to get rid of scumming on paper but when I put jobs onto thicker stock there's water everywhere through the job. Any ideas?

 

[Smck89]

I'm also having dampening problems on an SM 52 5 colour. I'm having to put the damp % up to around 30 to get rid of scumming on paper but when I put jobs onto thicker stock there's water everywhere through the job. Any ideas?

Should also say its brand new rollers that have been set correctly by a demonstrator and our ink and alcohol percentage have been checked.

 

[paul j]

weird damp issues

Did you have this problem before the new rollers were fitted? which manufacturer did you use?
You get a nice print on uncoated paper no issues with no washing out, when you go to thicker stock is it uncoated or is it silk/gloss. (If you have scum at 30% does this matter)
I'm assuming this problem is on all units.
If you have a long bead of water on the tail edge of your blankets then I would check the ipa, have you got a hydrometer, alcohol measuring glass tube with a float in it, just make sure the ipa is 8-10% no need to be higher, also check your fount solution at about 2%-3%, technotrans at 10 degrees (you know this already)
If its soaking the sheets wet then maybe one of the pans could be dripping or overflowing, They maybe crusty pan trays causing a capillary action and seeping down through the insulation as this can come away around the tray, peel off clean up and re-adhere with impact adhesive.
Also fresh filters in the technotrans as they clogg and stop the water from flowing freely, if they are newish it will not be that. You can remove the pan rollers and observe that the water is flowing away nicely down the drain hole, if not check the manual on how to set the return, but dont touch this unless you really really really need to. Can take a while to get it sweet - from experience.

 

[paul j]

Re check one unit yourself just for piece of mind

 

[mrheidelberg]

Have you moved the oscillator timing position ?
If not try another position eg. From white 1 to white 4.

 

[Grant B]

I agree with the above comment by mrheidelberg. I would also suggest checking to see if the ink forms are set to oscillate, particularly the last one (yellow-if it's the same as Speedmasters). If they are oscillating, try putting them in a lock position. Rarely do I ever allow the last form to oscillate as I find I get toning towards the tail end of the sheet.

 

[477sm]

Thanks for your input, Upon my ink rollers suggestion I have already reduced the occilation. I have come the this conclution. I had to double the amount of Etch I am using and set the ink rollers to the plate about half the recommended strip, seems to help. Etch recommendation is 3 oz I am at 7. Does not seem to effect anything negatively I am shocked. Also wetting the plate before I start seems to help.

 

[477sm]

basically I would be moving the problem area into the plate gap??

 

[477sm]

You could also have your ink manufacturer check the water pick-up of your ink, it could be too low. All inks must emulsify somewhat to work correctly.

 

[offset005]

hi guy ,
I need service (mechanical) pdf files of any printing machines. Plz send at
offset005@gmail.com

 

[turbotom1052]

im sure mr Heidelberg will correct me if im wrong but i think he is refering to the oscillation adjustment that changes the ink charge timing rather than the amount of side to side oscillation or even the amount of side to side movement of the form rollers.

 

[477sm]

OK you guys here is the thing, preliminary but promising. Without changing fountain solution that was previously mixed I:

1 Moved the oscillation from 1 to 3
2 reduced the amount of oscillation some
3 shimmed the #4 form roller it was stii moving 1/16 with the adjustments off.

Everything went exceptionally well this morning to all of your credit. The only problem is I am not sure which was the culprit or all of them were. Normally I would do one at a time but this was my own time.

Thanks
477sm