In the last step, the individual glass panes joined by a spacer are initially sealed circumferentially with Butyl (primary seal). The term Butyl stands for a specific butyl rubber recipe that is produced through the polymerization of polyisobutyls (PIB).
Following this butyling, the insulation glazing panes are sealed (secondary sealing) with a sealant, generally based on polyurethane or polysulfide. Some of the main properties of Butyl are the very high gas and water vapor impermeability, while the sealing material is primarily used to secure the stability of the insulation glazing pane and hold the Butyl cord in place, in addition to its sealing function. The standard edge connector height is approx. 11 mm.