UV Polymer Flat Bed Printers

[Carnie Bob]

I am interested in starting a discussion on this type of printer , my thought is this printer at the very high end is a device worthy of investigating. I will start
off with this question

Who here has knowledge of UV - XY coordinate flatbed technology and would you we willing to discuss potential applications?

my consideration for this is on many levels which include printing for what the machine is designed for and then adding photographic applications in a wet room.

Bob

 

[RalphLambrecht]

I am interested in starting a discussion on this type of printer , my thought is this printer at the very high end is a device worthy of investigating. I will start
off with this question

Who here has knowledge of UV - XY coordinate flatbed technology and would you we willing to discuss potential applications?

my consideration for this is on many levels which include printing for what the machine is designed for and then adding photographic applications in a wet room.

Bob

I experimented with this technology in the 1980s for my company as a way to build prototypes but the material was very limiting (extremely brittle) and the machines were very expensive.

 

[koraks]

UV - XY coordinate flatbed technology

That's two domains of technology, really.
I do know that for display applications, X/Y gantry-style inkjet printers with UV curing ink is used quite extensively. Is this what you mean? It's basically 'just' inkjet followed by a powerful UV LED array to cure the ink. Cf. Canon/Océ/RasterGraphics Arizona printers (used to be made in Vancouver, apparently now also/only? in Germany). Conceptually similar are 3D resin printers, but at a vastly smaller scale generally.

X/Y tech is quite pervasive these days also in the DIY domain with small-scale laser cutters, milling machines etc. X/Y/Z is of course common as well - 3D printers.

As to UV tech...well, there's a lot of that, too, pretty much everywhere...

Given the generic nature of these technology domains, the question is what you mean exactly; are there any products, systems etc. you can link to?

willing to discuss potential applications?

That's a very open-ended question. The question is whether you intend this discussion to involve people who will (literally) put their money where their mouth is and invest financially or through some kind of collaborative R&D effort.

Btw, I'm sure you're aware of this, but for a decade or so, "2.5D printing" has been used in niche applications. It's basically inkjet, but with very thick ink layers. One firm that apparently still actively pursues it is Mimaki: https://mimaki.com/product/inkjet/i-flat/jfx200-2513-ex/feature.html

 

[Carnie Bob]

Any thoughts on applications of this type of technology... My goal is to remove the digital negative separation stage and go direct in multiple register for Pt Pd and gum

 

[koraks]

Any thoughts on applications of this type of technology...

Funny enough that's one of the things I referred to in the blog I wrote two months ago about where to take this hybrid technology stuff: https://tinker.koraks.nl/photograph...e-of-digital-output-for-alternative-printing/
I mentioned Lüscher in the 'direct laser exposure' section.

I think it's promising and @AndrewBurns on here as experimented with things in that direction. My blog page features a few early examples (cyanotypes) he kindly allowed me to share. The key things to optimize would be resolution and throughput; you need a lot of laser power and/or several parallel lasers to get any decently rapid printing speeds, and some pretty advanced tech for focusing sufficiently small dots (and making them align properly). This is the kind of stuff Lüscher to an extent will have solved, and it comes at a price - obviously.

Conceptually I think this kind of approach is the way forward - or at least one of the ways forward. Personally, it doesn't appeal all that much to me because quite frankly I just like to stick to my archaic ways of printing from negatives. It's irrational, but much of printmaking is, so there you have it.

I would consider direct laser exposure attractive once the dot pattern isn't clearly visible, tonality can be made sufficiently smooth and it doesn't cost a ton. Presently, I don't think it quite ticks any of those boxes.

 

[AndrewBurns]

Yeah I've played with direct laser exposure of cyanotypes, and have also gotten some good results with area exposure through a transparent LCD screen.

The thing with laser exposure is that it comes down to two things, speed and power.

If you want the dots to be so small as to be invisible (on the order of 30 to 50 microns probably) then you need a lot of dots, and if you want the print to be done at any reasonable speed you need hardware that can 'write' those dots extremely fast, like on the order of a few hundred thousand dots per second if you want a reasonable sized print to be done in less than a few hours.

And if you're 'writing' dots that fast your exposure time is in the microsecond range, so you need to get enough UV power onto the paper to fully expose your chemistry in that length of time. My LCD screen exposure unit puts approximately 30W of UV power onto an A4 sized piece of paper for an exposure time around 4 minutes. Unless your laser source is also 30W of output power, it will take longer to expose that same area with the laser, but most cheap available UV laser diodes have an output power of between 500mW and 1.5W, which means that the laser would either take MUCH longer, or you'd need to use at least 20 laser diodes in parallel to get the same exposure time. That's why if you look at those Luscher machines they talk about a single machine having up to 128 laser channels, that's how they can get a reasonable exposure speed.

It's similar to an inkjet printer, the print head actually has many nozzles per colour channel and writes a 'stripe' of ink across the page, imagine how long it would take if the printer only had a single tiny nozzle per colour and had to scan the head back and forth tens of thousands of times per print. I'd imagine you could do the same thing with lasers (have dozens of laser diodes writing a stripe of print at a time) but I decided that project was probably going to be too costly and time consuming for me and I was getting better results with my LCD screen unit.