Ink Banding Problem

Hi All,

We have a 1997 Speedmaster 102CD Five Colour and we are getting a 5mm band approx 110mm from the grip of the sheet on all units. It is most noticable on screens but we have run dry solids as well and you can still see it but not as obvious so we have discounted the damps as being a problem. Does anybody have any suggestions. Thanks in advnce.

Jon

 

Probably plate or plate processor problem. Check the chemistry and the roller pressures. You shouldn't have the same problem on every unit on the press.

 

Hi William,

Plates are fine they are perfectly clear, we even tried developing a new set back to front just to make sure we werent getting a bow wave on the dev tank, we have also checked all the roller settings and adjusted but the band is still there.

Thanks

 

try adjusting your reciprocation if its on full move on to half for starters to see if it makes any difference also if your rollers are getting old try changing just one deck and see if it cures it. We are in Manchester if you dont get it sorted give us a bell

 

Does it have the problem when the Varios are on/off? Also, did someone set your forms to full oscillation for a particular job? Sometimes that can cause a problem with banding.

 

Hi,

Tried adjusting the reciprocation on and off(and everything in between), we dont have Vario so it cant be that. We have also tried lifting all the forme rollers off the plate and dropping them in one at a time to see if one them could be identified as the culprit but it makes no difference. Our operator thinks it could be happening when the sheet pulls off the blanket. We have also tried a different blanket and tried gelling the ink down.

 

if your getting it with just one inker roller on it then it might be when the sheet transfers from impression to transfer inch one of the sheets with the mark into the press and see if it lines up when transfers if its that you need the timing set how many impressions has the machine done?

 

Hi LLS,

Thats what we thought as well after messing around with it for most of the morning but discounted anything mechanical as it was on all five units. We had rollers in and out measuring them and re setting them. We have only had the machine for 3 months and have previously been on Rolands so are coming to grips with the speedmaster slowly now. After getting everything back in we decided as a last resort to change the blankets and packings(they have only been on for a few days) and hey presto all the banding had gone!! I have got the blanket company coming in to take them back for testing. Thanks all for your help it is much appreciated. I have you number now off the website and if anything else comes up I will give you a call.

Cheers

 

No worries if you have any problems we are always happy to help

 

Is the banding lighter than the surrounding area or darker?

 

Its possible that your problem is being caused by a build-up of dust, dirt, lint and hair that sticks to the wet ink on the bottom side and backside areas of the print head assembly.

 

banding

Have you been able to solve this banding problem?

 

Yes, we changed all the blankets and packings and whilst not perfect it was a lot better

 

A salesman at our company calls it the Heidelberg streak. My supervisor suggests main motor slack. My pressman suggests a trapping issue. I agree with my pressman. Changing color rotation helps. Paper and ink. The quality has gon down.