Acrylic usage in SLA printers
It's bothered me for some time that acrylics are so prevalent in SLA machines of all flavors (ours included). I see it in vats, mounts, shields, covers, etc depending on the machine. Unfortunately, this particular material seems susceptible to spalling if not properly cleaned immediately after resin contact- a bad choice for printers, I'd think! Over time vats become tacky, appear to slightly dissolve on the edges, etc.
Why is it so prevalent? I'm aware that it is inexpensive and easy to find in everyone's favorite orange, but it just doesn't feel like the right material. UV transmissability isn't a huge concern I'd think, since most of us are actually referring to the low blue spectrum when we say 'UV' curing (~400nm+), which other plastics can handle (PC, for example). Even then, with flex vats becoming more popular, the only transmission-critical part of the printer is FEP. Color and chemical resistance could be applied via a coating or film treatment, but this isn't done, to my understanding. One of my easier Draken mods was to layer my big acrylic door with a thin vinyl film, for example. No more spalling!
The mix of chemical resistance and mechanical properties in an inexpensive, available plastic is the best reason I can come up with- and I don't consider it a bad one in many instances. What confuses me is why it is used in places that don't require it, and where other materials might perform better.
tl;dr many parts of the printer could be made out of a more chemical resistant plastic but aren't, and also aren't even coated with a protective layer (spray, film, etc) in many cases. Is acrylic just 'good enough?'