- will pass UVB
- Is used in tanning beds
- Is used as covers for some pet cages
Plexiglass -G UVT can also be used to make a "heat shield" to get vitamin D from the sun without getting too hot.
Just need to add a coating to it.
to absorb/reflect some of all of the UVA and IR portions of the spectra
so that a person could get vitamin D from the sun without getting a tan (UVA) or getting too hot (IR).
At a minimum the coating could just reduce the IR
A better costing would block all of the IR
The best coating would stop UVA and IR but pass the visible light
An acceptable coating would stop everything above UVB: UVA, visible, and IR
Wikipedia Spectra for mirror coatings
VitaminDWiki added UVB spectra
It appears that a mirror made of Plexiglass G-UVT coated with silver (Ag) might make an acceptable coating
All of the UVA, visible, and infrared would be reflected, and only the UVB would pass thru the mirror.
Video on how to add a silver coating using chemicals by http://angelgilding.com/
Mirrors can also be made with very thin silver leaf attached to the "glass" with gelatin - see PDF attached at bottom of this page - also by http://angelgilding.com/
The gelatin might absorb the UVB - not sure need to check Google Images
Can protect the chemical or leaf silver by sandwiching it between two layers of plexiglass
5 square feet of silver leaf costs as little as $8 and shipping
Would need at least 4 packages (20 square feet) to make a silver plexiglass mirror large enough to provide just UVB to an adult.
- Get vitamin D (UVB) with minimal tanning (no UVA)
- Possibly get 4X as much vitamin D per minute than if in the direct sun
(UVA, which seems to cancel some vitamin D production, is blocked by the heat shield)
- Can spend more minutes in the sun when you do not overheat (especially good for those with dark skins)
Plexiglass datasheets are attached at the bottom of this page
- UVA decreases vitamin D
- UVA from some tanning beds and most windows decrease vitamin D blood levels – March 2012
- Ways to block UVA but not UVB which makes vitamin D which contains the following image
- Business opportunity – you can now make stuff which only passes vitamin D wavelength
Some sunscreens block UVB more than UVA - the exact opposite of what is wanted (dashed line)
- A ‘universal smart window’ for instant control of lighting and heat Aug 2013
Can turn off Infrared as well as visible light, Nanocrystals of indium tin oxide pass/block just the infrared
If these nanocrystals could be used with plastics which pass UV, then people would be able to get the benefits of Vitamin D without the heat.
- Example supplier on internet $25/square foot Dec 2015