Re: Photopolymer Plates
We've only ever used Fuji LP-NV plates so although I can't make comparisons aIl can offer my thoughts on the plates + process.
The main feature of the LP-NV plate is, like all Fuji plates they are incredibly consistent and stable. Linearisation is checked twice a week and we very rarely have to change it, even after a full chemical change.
Our plates are imaged on an Esko-Graphics PlateDriver 4 and we get good speeds, faster than thermal. We run at 200lpi as standard and see virtually no issues with dot loss in highlights, nor with excessive dot gain in shadows.
We get through 1200+ B2 plates a month, we change the bath every two months and the gum probably once a month. Again, no issues with the quality of plate image or consistency, we get the same at the end of the month as we do at the beginning.
Run lengths are generally excellent. While our average run lengths are nowhere near the max of the plate, when we do have long runs the plate copes very well with some plates having lasted well into 6 figures. Run length is related more to paper and ink (i.e. some colours are less forgiving as are some papers, and the printing order).
The only real issue is with the processor, mainly the impact of the chemistry on the rollers. Although I'm led to believe the process is much cleaner than Agfa's silver and as such the processor in general requires less cleaning, great attention does need to be paid to the dev exit rollers in particular as they do dirty quite quickly.
The upshot is the surface of the rollers get coated with what I'd describe as a glaze - a calcium-like build up that means the rollers develop a hard surface. This means the rollers lose their ability to squeegee off excess dev and cross-contamination occurs.
However this really is the only issue I have. We've never had major issues with the rest of the process - preheating, PVA layer etc. So long as the processor is kept clean you'll be fine.
Storage is no issue, plates can be use weeks after processing without the need to re-gum or re-treat the plate.
Handling-wise, pre-exposure you need to handle carefully so the PVA layer is not damaged. If you're using auto-loading CTP this shouldn't be an issue.
Post-process athough they look very similar to 'conventional' UV-exposed plates the anodised coating is a bit softer and they need to be handled with a bit of care so we interleave plates for storage.
In all, LP-NV is a great plate for the commercial environment, if you're looking to switch now then I don't think you'll be disappointed. All I'd say is watch out for process-free violet, it's just around the corner. Agfa's offering works on current laser powers whereas Fuji's needs higher power than current machines offer.
Edited by: Colin Gilham on Nov 2, 2007 6:58 AM