1. Presentation

1.1 History

The first patent for insulating glass was filed in 1865 by an American glassmaker, T.D. Stetson.

More than a century later, in 1942, Libbey-Owens-Ford developed "Themiopane", a technique for joining two sheets of glass using a metal joint (ductile metal) welded to the glass (figure 1 ), with the same coefficient of expansion.

In the 1960s, the "Tege" (Twindow Glass Edge) was launched: this is glass-to-glass, welded glass-to-glass (figure 2 ), without any interposed material. The included air space is 4.8 mm thick.

In Germany,...