Xante/ink

[Shropshire Printer]

Hi,

I'm a partner in a small jobbing printers (single + spot colour litho and short-run colour digital). We run a pair of Heidelberg QM46-2s, using either poly plates or metal, plates and film imaged on a Xante Platemaker (currently a 5 but we've had the same problems on an old PM3).

We've recently been suffering serious image breakdown problems on the poly plates. I won't bore you with all the details, but after exhaustive (and exhausting!) tests we seem to have narrowed it down to the black ink we're using.

Several years ago we found that the formula of the Akzo Nobel we had been using had been changed, resulting in it acting as a solvent on the image layer. Nobel just said " no one else has reported this problem, but our tech support people will be in touch" - they weren't. I contacted our plate supplier (we use the Myriad polys), who recommended Hostman Steinberg Quickset - RESULT!!! - until about three weeks ago when the old problem reappeared.

Basically fine screens (120 lpi) begin to break up after 800 /1,000 impressions - most obvious in the highlights. This DOESN'T happen with coloured inks supposedly of the same formulation. It is most obvious with text over a pale tint background - the dot vanishes first in the counters of Os, Bs etc.

It became clear that it was a solvent effect of the ink when I realised that if a plate was inked, even for just 15 or 20 cycles, then left standing for a few minutes, the image would fall apart after a few impressions on resumption of printing. Attempts to find an alternative have proved useless - everyone says their ink is fine with plates from the Xante (we tried K+E and that was even worse) - all we've heard from anyone to do with Xante is "most customers don't try to use them for halftone work (so why don't they say that in their ads?????).

Has anyone had similar problems - or better still know of an ink that's actually going to work??

 

[Ludo_au]

xante

xante

I have used the Myriad plates with Xante and GCC Elite (basically a Xante with a different badge). I have had similar problems but i have never looked down the ink angle. I have basically found that the heat fuser roller in the machines loses its heat as it gets older. I used to try all the standard answers and they work for a while. Set the printer to thick, run the plate through blank a few times after you have imaged your plate (you may have already tried these). Recently I brought a new fuser roller from GCC for my GCC printer and this fixed the problem straight away. I hope this helps, I know how frustrating it is when everyone gives you the same old answers but it is the best I can do.

 

[Eddieg]

would your ink be a bit stiff? try putting gel into it
i run a 3302 2 col with varn i try to keep the pressures off as much as possible
i changed my fount to varn universal pink and this has helped no end
hope this is of some use
edd from N. Ireland

 

[matthew_willmer]

Fount is key, I had a QM46-2 running these laser plates; I never ran halftones. You will need too let the dampening units build up on PU1 & PU2 & run 40$ make ready through, but I only ever got away with line work. Universal pink is the best bet as it contains not Alcohol, & low acid count ai it keeps the fused ink on the plate... A little hint some body told me, was when the temperature builds in the print room, place the 2 water bottles in your fridge all the time not in use and this will help with keeping the plate wetter for longer.... good luck with this, I moved on to a true 2 colour press with a Silvermaster eco1630, I haven't looked back.