Consistent quality in insulating glass unit (IGU) fabrication depends on systematic sealant validation. Before sealant application, adhesion and compatibility tests must confirm that the two-part sealant bonds reliably to the substrate and will not undergo adverse chemical reactions with the glass, spacer bars, or ancillary components.
During processing, continuous extrusion testing verifies consistent sealant flow. The butterfly test confirms uniform mixing of the A and B components, while the snap time test validates that the mix ratio is correct. Sealant dispensing quality should also be inspected.
Finished units require a cut-and-peel test to verify the sealant-to-substrate bond. This destructive check confirms that the cured sealant has achieved the adhesion necessary for the IGU’s long-term structural performance and service life.