The demand for new materials with high strength to weight ratios has created a dramatic growth in sandwich composite technology. Sandwich construction employs a lightweight core that has a flexural strength and flexural modulus far exceeding that of skin laminates alone. The main disadvantage of honeycomb-type cores as used in a variety of industries is that of delamination which can cause catastrophic failure. This is caused primarily by the failure of the bond between the facing skins and the core, due to the very small bonding area that traditional honeycomb cores edges offer, and the fact that they are closed cells, causing a build up in pressure over multiple cycles of pressurization. The most common type of core material is honeycomb, used primarily in the aerospace industry.

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Each cell in a honeycomb sandwich is an airtight vessel. When heated, the air in each expands, increasing pressure. If the pressure gets too high, the film adhesive bond may fail, initiating a delamination. Hexaflex prevents this from occurring because it is an open, fast-venting core design that prevents any pressure differentials from building up within its geometry. If necessary, one could quickly purge the assembled Hexaflex sandwich panel with gasses or liquids by virtue of the 3 vent ways that inherently run through the inside core design. (a)

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The outside presentation (b) shows a closed configuration with holes which can be filled with suitable material, such as a metallic foam plugs (c).

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