Ink build up on XL 75 impression cylinder and plate cylinder

Hello,

I'm a fairly new pressman, just getting trained at my current job in NY

for years we've had ink build up on the grooves of the impression cylinder and on the plate cylinder. The impression cylinder also has buildup around the edge all the way across both top and bottom of the cylinder (really thick ink sometimes if we use PMS on the 5th unit). It's gotten to a point my co worker and I need to know why it's happening. we shutdown on fridays just to clean the ink off the grooves on the impression cylinders and the plate cylinder, literally an hr and half's worth of cleaning just the cylinders. God forbid we miss a week and the next week the ink buildup is worse and takes us 2 hrs to cleanup.

We feel the ink is dripping from the ink fountain because maybe the wedges are wearing out and also maybe the plastic liners used, could that be a possibility? take note that we use only products made by heidelberg or recommended by them. 0 cutting corners when it comes to the products.

Another thing is we feel the last few ink keys may be too open and it's leaking ink onto the cylinders.

Any thoughts why we're having this problem? On friday I'll be happy to take pics of the sheer ink buildup.

 

Hi,

If the ends of the ink fountain roller, that press against the duct ends/wedges are clear and free from ink then they should be okay. It's when you start getting a thin layer of ink going underneath the duct ends, right to the end of the fountain roller, they need replacing. (they'll be something like $70 a pair)
The plastic liners are quite durable, and only need changing if there's a split allowing ink onto the actual keys. We only change these every 3 or so years. more for cosmetic reasons really.

Are the form roller journals shut, that allow lateral form roller movement when trying to eliminate any repeating lines? It's very rarely that we actually run with these open, and when we do it would be the middle two form rollers only. (Running with the journals open would require more water to prevent any catch-up because of the rollers "skidding" across the plate)

I have seen the situation with the outer edges receiving to much ink when there's none or very little image, leading to ink building up at the extremes. To fix that you'll have to adjust the characteristic curves. Quite complicated to explain here, but if you go into the adjust curve menu, look at the DIO setting for 0% which will be on the left hand side of the graph, I'm guessing yours will be around the 40/60 DIO range, where I'd reduce that to around 20 DIO. In theory you'd think that could be set to zero, however you still need some ink to be going on. (you'll have to change this setting for all three paper type curves) Ideally on the console, there should be around two diode lights illuminated for the edges in none image areas

In general, make sure when fitting the duct ends you put a small amount of grease on them to help minimise wear against the ink fountain roller. After you've cleaned the bearers and recesses go over them with an oily rag to help prevent the ink sticking hard to the cylinders.

Hope this helps.
Time issues at the moment so will post about imp cyl ink build up later. Photos would be good.

Steve