Molten glass is turned into insulation at the Johns-Manville Corporation in Berlin, New Jersey the orange-hot fluid is forced through holes in a palladium sheet to form long, thin fibers.

The blown-in insulation and broken glass filled our hair and eyes.

I prefer the sliding glass doors for three reasons. They are a really good size for a batch heater, they are tempered safety glass and they are double layered for insulation.