I have a small A3 size uv printer I use to color wood for my laser cutting…
It has water cooling to keep the LEDs cool.
I was thinking of upgrading to a fan cooled LED unit and getting rid of the water system and water tubing on the gantry print head…
Not exactly a laser topic, but I know there are many diverse folks here that might have an opinion…
There are three types of UV LED wavelengths used for curing, so it seems…
see below:
** 365nm (UVA): Excellent for deep penetration, curing thick layers, pigmented inks, and complex shapes; it offers thorough curing but can be slower than longer wavelengths.*
** 385nm: A good balance between surface cure and penetration, often used in inkjet printing for efficiency.*
** 395nm/405nm (UVA): Focuses on rapid surface curing, ideal for clear coatings, thin applications, and where speed is critical; 405nm is very fast for surfacing*.
QUESTION: I use hard ink in this unit and this last batch of white seems to be a little thinner and whenit cures it turns yellow, ie. curing too fast and buring with the current LED light intensity that is not variable…
So…of the three choices, it looks like 395nm may be the right choice…
but I am not sure if the other inks which take longer to cure, then maybe the 385nm is the good balance and using the intensity adjust will balance all the thin and thicker type inks…
I’d expect that to have either lower optical power or a shorter LED lifetime, perhaps both, because the heat transfer rate of air cooling is terrible compared to water cooling.
Another way to look at it: water cooling requires expensive, awkward, and fiddly equipment. If there had been any way to cool the LEDs with a simple fan blowing air across an aluminum heatsink, that’s what they would have done originally, because cheap.
This started when we bought a new batch of white ink.. I think it is a thinner type than
the colors MCYBlk and when I make a white sheet the color yellows, all the othe colors work great with the white as an undercoat…
So I think I may try installing in the ganty the UV LED with fan and intensity adjust, just to see if This give me a little flexibility… it is only when I print White only sheets, but ai can do these on the big UV Printer for now… Can’t stop the engineer in me changing a design if I think it will make thinks better… also fun…
I have been looking for some info on thick or thin inks… and mostly additives…
but for now we are just sticking with one vendor
I remember you mentioned some weeks ago, the new ink batch.
Just a thought, Could a UV strip light be used to speed up the drying of varnishes etc that seem to take ages to cure properly, and be used to form acrylic for frames.
Could a UV filter be used/added to bring the drying/curing effect into the tolerance of the ink so no yellowing.
We use a large uv lamp set up fir drying letter size sheets…
but the UV lamp on the printer moves with the ink being layed down and cures it on each pass…
so since the intensity is not adjustable it seems to be scortching the white layer of ink…
the ink dries just fine, but actually TOO much uv light intensity for this white ink…
