So I’ve looked at DI presses for awhile and asked many questions in here about them. What I’ve seemed to find is the biggest downfall of them is the 12x18 sheet size. I couldn’t for the life of me understand why they didn’t go larger. Then the other day I found this. The KBA Karat 74. It’s B2 sheet size. No ones ever mentioned this before. Is it a bust as a press? KBA is a pretty quality name, so was wondering what people thought about it. Essentially it rivals the indigo 10000 with the sheet size and I’m sure cost per print is way better and is faster. Just curious if anyone has experience with one and what that experience was. Seems like a good press for andthing but the longest sheetfed runs.
It seems to be just another of the press concepts that did not take off to be a success. There are quite a few of them.
Anyhow, I analyzed this press (Karat 74) along with the other related KBA press concepts, Genius 52, Rapida 74G, and Cortina press about 12 years ago. Slightly different design approaches, all of which in my opinion are not too good.
The Karat press is a bit more different than the rest because each of its two plate cylinder carries two plates and is inked from two different Gravuflow inkers. So two of the CMYK plates will be on one plate cylinder and two on the other. The impression cylinder. Due to this situation, the paper on the impression cylinder is required to revolve two times to print the image from each of the two plates. This means that mechanically (and printing speed) , the Karat press impression cylinder is required to rotate twice as fast as a conventional sheetfed press having the same output of sheets per minute. One should be able to see that this is going to tend to limit future speeds.
I think the issue about larger presses has to do with set up time.
If one has a small DI press, then having the plates in a cassette in the plate cylinder can make sense. But for a larger press, this might not be such a good option. Therefore one would have to hang a large plate on the press.
So let's compare that makeready times for just obtaining an imaged plate on press.
Conventional press.
Hang a pre imaged plate. X minutes
Large DI press
Hang non imaged plate X minutes
Image plate Y minutes
One should be able to see that obtaining an imaged plate is faster on a conventional press than on a large DI press.
Conventional X minutes
Large DI press X+Y minutes.
In general, DI is a dead end technology.
Press manufacturers in general have not had a very successful history of innovating new printing technology. The number of failed efforts is quite high and the reasons for the many failures is quite clear, if one knows how to analyze them. They don't know what they are doing and this results in them going back to the conventional concept that they are so familiar with.