IGMA Technical Presentations Focus on Adhesion and Durability

HALIFAX, August 9-Today's technical presentations that were part of the Insulating Glass Manufacturers Alliance summer meeting, focused on adhesion and sealants, as well as insulating glass durability.

The session began with a panel discussion about adhesion. Panelists were Chris Barry of Pilkington North America, Lori Postak of TruSeal technologies, Bruce Virnelson of PRC-DeSoto and Lena Chernyak of H.B. Fuller.

Barry began the discussion, and talked about some of the necessary measures IG manufacturers should take in order to ensure adhesion. He advised having suitable solvents to dissolve dirt on the glass, hot water to speed dissolution, rotating brushes that push the water away from the rinse and clean rinse water. He also cautioned manufacturers to not seal an IG that is still hot from washing, as it would create a dished unit.

Virnelson next talked about adhesion theories and test methods, and encouraged manufacturers to choose test methods that are best for their specific applications, as there may be several that are suitable.

Postak spoke about quality inspections and confirming IG sealant durability. She advised managers to instill good manufacturing practices, provide troubleshooting guidelines, to define the final inspection role, to follow up on failures in the field, demand supplier certification of properties and to perform regular on line inspections.

Chernyak continued the discussion on adhesion, further looking at theories, testing and other practices manufacturers should follow in order to ensure a successful sealant.

Bob Spindler of Cardinal IG gave a presentation on the effect of glazing sealant thickness on glass breakage. He talked about characteristics of glass breakage, glass fracture analysis, including thermal stress, bending stress and impact, and stress analysis with glazing sealants. He stressed the importance that IG manufacturers and window manufactures follow the recommendations for use provided by their suppliers. He explained that if you use products incorrectly, such as a silicone glazing, it could lead to a failure. His recommendations to reduce failure included:

  • Using 2.3 mm heat-strengthened glass or thicker on lites experiencing breakage;
  • Providing clearance between glass and sash to reduce opportunity for contact;
  • Following IGMA glazing guidelines for sealed glass units;
  • Making sure the edges of glass are not damaged during glazing;
  • Providing a minimum sealant dimension of 0.030 inches between sash and glass; and
  • Conducting stress analysis to determine the magnitude of stress during glazing.
Today's sessions concluded the IGMA summer meeting. A full re-cap of the meeting will be in the September 2005 issue of USGlass magazine.

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