WDMA Takes on Gas Permeability Research Project

The Window and Door Manufacturers Association (WDMA) is co-sponsoring and participating in a research project on gas permeability in insulating glass units to provide technical information on the gas permeability rate through sealant membranes and edge seals.

"Considering the effect that sealants, by their very nature, can have on argon or krypton and the impact on the thermal performance of a unit, we believe the results will be invaluable to every manufacturer," said Al Campbell, president of WDMA.

The multi-phase, multi-year project has generated interest by the insulating glass industry, government agencies and consumers, according to the WDMA.

One of the objectives is to develop a library of transmission rates that is representative of commonly used and available sealants, fill gasses and mixtures. This phase of the project is developed to help IG manufacturers understand the thermal performance that can be expected when selecting combinations of materials. They may also use this information to create mathematical models to help determine gas loss from an IG unit.

In the second phase of the project, the geometry and interaction of components in a unit is used to study the gas permeation.

Next, they test for mechanical and environmental stress which can provide some indication of the extent of loss under inferior conditions.

The final phase is the development of an improved test method for measuring gas loss from standard IG test size unit, which is expected to offer the advantages of speed and reproducibility compared to current tests.

Unlike other test methods which consider the unit's construction, this test will evaluate sealants only, according to WDMA. Argon will be used as the test gas; helium will be the carrier and the area of permeation will be determined by the design of the cell.