Question on how welding glass is made

These dark green protective glasses are made of the same chemicals as normal glass sheets used for windows. The main components are: silicon oxide (quartz), calcium carbonate (limestone) and sodium carbonate (soda ash).

The only difference is the dark green color, which comes from high amounts of iron- and chromium oxide.

Regards, Andy

And the exact chemical composition probably is propritary to each company that makes it, since it has to pass specific tests for Shade rating for various kinds of welding (shade 12 for arc as I recall, shade 5 for torch) As long as it passes the tests, the material can be made many ways, including plastic.