3D Printing - "It's all about design and quality output. Not how fast the printer can run."
I have had some concern about the UV radiation used in DLP printing. In my former life, one of the hats I wore in my career was that of a jobsite safety manager. I was in the energy conservation business and a lot of our work was in the HVAC (Heating, Ventilation, and Air Conditioning) of very large buildings.
One of the jobsite hazards was in the use of high level UV-C radiation inside return air duct systems to purify the air. Some of these ducts are large enough to easily walk through and some have a normal looking man size door for entry. Warning signs are posted about UV light in use. Exposure can damage eyesight the same as looking at a electric welding arc.
The printing UV is in the UV-A (Near ultraviolet) range which is closest to visible light. The greatest UV danger for eyes is in the B and C (shorter wavelength) ranges. B is the sunburn range and C is the air purification range. Natural UV-C from the sun never gets through the atmosphere to the ground. It's all created by sources on earth.
The UV-A for printing (and resin curing) source should not be directly looked at for any length of time. Same issue as staring at any visiable light source. The problem is the UV-A source doesn’t LOOK as bright as it is. Ever look into one of the new LED normal flashlights? You would know how bright these LEDs can emit radiation.
So being around the UV-A light of my printer and soon to be built UV-A curing box is not high risk. Just don’t stare into the light. Here is a link for more UV information. https://en.wikipedia.org/wiki/Ultraviolet .
I did my homework on UV light as I an about to build my own UV curing box for my resin printed items.
I have ordered two 10-watt LED lamps that operate in the spectrum of 395nm – 405nm. Because they are not the florescent tube type, all the light power is transmitted in one basic direction. I think 20 watts will be fine. If curing is too slow, I can add another 10 or 20 watts. These lamps can be purchased as high as 50 watts each. I picked this brand because the spectrum of the emitted light is the sweet spot for resin curing.
I also ordered a low cost solar powered turntable so the parts being cured will be rotated during the exposure.
I am not the first person to design/build a cure box. I will show it off once I have it working. I hope it works. That’s part of the enjoyment for me. Solving problems and making things.