Viracon’s insulating glass units configured with aluminum and stainless steel spacers are constructed with a dual seal configuration where polyisobutylene (PIB) is the primary seal and structural silicone is the secondary seal.
PIB is the primary seal of the insulating glass unit preventing moisture vapor transmission into the unit’s sealed space. The silicone secondary seal acts as the adhesive that holds the unit together in both conventional and structurally glazed systems. Both the PIB and structural silicone must maintain adhesion to the glass and spacer throughout the life of the unit. Silicone is uniquely resistant to ultraviolet light and is the only sealant capable of being exposed long term to UV, temperature extremes and harsh atmospheric conditions. The high strength of silicone makes it ideal for structurally glazed applications.
Viracon’s insulating glass units configured with VTS are constructed with a single component spacer consisting of a black thermoplastic with integrated desiccant and polyisobutylene (PIB). VTS is chemically bonded to the glass and to the secondary silicone sealant, eliminating the need for added vapor barriers, acrylic adhesives, additional desiccant or PIB