Cork is a natural material that has historically been relegated to uses not associated with the technology, such as bottle stoppers and bases of frames for fixing warnings.
More recently been shown that the cork is the best available material for the construction of vehicle bumpers.
Now, the composite symbols maximum of high-tech materials, their performance had multiplied by several orders of magnitude with the aid of a material that has been overlooked by technology, despite its low cost and their properties more than interesting.
Engineers found that the cork can be the best option to form the “sandwiches” that are the hallmark of these composite materials used in aircraft and aerospace applications.
“Cork is a natural product with intriguing properties,” agrees Jonghwan Suhr of the University of Delaware.
“It is energy absorbing, lightweight, impact resistant and has excellent vibration damping properties and acoustic. Its unique cellular organization also results in good thermal properties, and it is impervious to moisture,” he lists.
Suhr and his colleagues were interested in the cork when searching for a material that could reduce the noise inside the aircraft .
The composites used in aerospace applications are layered structures, foams and fibers mixed synthetic materials or with honeycomb-shaped structure, between the plates of carbon fibers embedded in resin.
The result is a material unrivaled in terms of strength and lightness.
Unfortunately, these materials are also very good at driving noise, which is a huge problem in a plane.
The solution adopted today is to line the space between the internal and external structures of the plane with a wall 10-15 cm glass fiber. This, however, increases the weight and reduces the internal space of the aircraft.
The researchers then had the idea of creating an additional layer with composite – a layer of natural cork.
And the results have exceeded expectations.
“We got a 250% improvement in sound insulation using the cork without any sacrifice of mechanical properties,” says Researcher. “In addition, cork is sustainable and environmentally friendly because its production involves the emission of carbon.”