UV boxes have become a hot topic because they are the final piece of the puzzle ensuring a high quality output. However, it can sometimes feel like a minefield out there when you can see a $200 UV box beside one for $2000.
Some of the typical questions should be:
- What am I trying to produce? (e.g., Link Lab, Class 1 and Class 2 Medical Devices) article; or
- How many am I trying to produce each and everyday?
If you are trying to produce models or lab products for non-oral use then a more inexpensive box could suffice. An oral use product most definitely requires a compatible and pre-validated UV box.
UV box functions
Some UV box functions are more important than others. You should pay particular attention to the following when evaluating UV boxes:
Flash – Using a flash function ensures the curing is not only at the surface but also penetrates deeper into the printed parts. The is essential for parts that must be thoroughly cured to obtain the desired mechanical and biological properties of the finished piece.
Mix Matrix LED Spectrum – Most inexpensive UV boxes use a single wavelength LED which is usually 405 nm. It is suitable for a basic level of curing but certainly not a complete cure.
The use of a mix matrix LED spectrum from 365/385/405 nm gives a thorough cure by penetrating deeper into the material and reacting with the photoinitiator more thoroughly. This setup is usually found in a more premium UV box.
Use of Nitrogen – Often found in more premium UV boxes, to create an inert environment in the chamber during the during process. The use of nitrogen gas creates an inhibition layer around the part whereby bacteria and other impurities are unable to stick to and get cured with the part. This ensures the biocompatibility of the printed piece.
LED optical Layout – Optical layout of the LED is critical for a thorough and even cure.
Most inexpensive boxes do not have 360 degree curing and therefore require flipping of parts so that each surface has necessary exposure. However this is not as simple as it seems. Curing on one side creates an inward shrinkage in a particular direction. Flipping it and curing parts will lead to shrinkage in another direction overall the part will not be as accurate as a 360 degree part.
An inexpensive box requires double the curing time compared to a box that cures 360 degree of the piece due to the flip action.
Curing time Preset – An inexpensive box requires manual input of curing time for every single print which means you must remember the curing time for the corresponding resin while the premium UV boxes have a preloaded curing time, eliminating guesswork or input of curing time forever.