15.11.2017 change 15.11.2017

The material protecting planes struck by lightning - closer to commercialisation

Photo: Fotolia Photo: Fotolia

Every airliner gets struck by lightning once or twice per year, and although current lightning protection solutions protect passengers almost completely, researchers are working on a new material for the exterior of the plane's plating - lighter, cheaper, durable and conductive.

This innovative material that minimizes the effects of lightning strikes has already been submitted for patent protection; its commercialisation is probably a matter of a few years.

Dr. Andrzej Katunin, associate professor of the Silesian University of Technology in Gliwice, who supervises the work on this material, explained that the material is entirely organic, metal-free, a mixture of polymers that conducts electrical current.

"In order to obtain good mechanical properties while retaining electrical conductivity, we have combined a conductive and dielectric polymer with good mechanical properties, and we have also made a number of simulations that allowed us to identify the appropriate proportions of these materials so that the result is a rigid, durable and electrically conductive material"- he explained.

Research on the new material has taken a few years. So far, researchers have been able to synthesize the polymer within the framework of a previous project funded by the Foundation for Polish Science.

"We then finished our invention, namely, we applied carbon fibre to add appropriate stiffness, we further modified the chemical composition of this material and submitted the first patent application this year" - he said.

Katunin added that the material had already undergone mechanical, electrical and high current tests when it was "shot" with artificial lightning. The tests have shown, among other things, that the new material does not focus the energy in one place but dissipates it.

"All the tests have confirmed that our idea works and we are now moving towards the development of this material for lightning protection and in addition electromagnetic shielding (the safety of the machine during landing and taking off at airports where the field has high intensity - PAP). We are moving towards commercialisation of this solution, increasing its technological readiness, and if we succeed, perhaps marketing it in a few years" - said the researcher.

He added, however, that entering the aviation market is very difficult and involves having to meet very strict standards.

The researcher also said that while statistically every airliner gets struck by lightning 1-2 times per year, aircrafts are now well prepared for lightning protection; as he said, the last plane crash caused by a lightning strike and resulting fuel tank explosion occurred in the 1960s. Still, due to the development of modern technologies, the need for new solutions in this area is quite high.

Katunin explained that the aviation industry currently uses solutions based on metal mesh embedded in the polymer hull.

In order for the lightning to not destroy the machine, the electric charge must be quickly distributed across the entire hull. This will prevent high temperature at the strike site, which could damage the plating. Plane hulls are built of composites based on epoxy resins. This durable plastic is light but does not conduct electricity. Thus, metal mesh is embedded in the polymer hull. At the moment of lightning strike, it captures electric charge and heat.

"These meshes perform very well in terms of electrical conductivity, but it\'s a very expensive technology, plus metal makes these structures heavier" - said the scientist. He added that aviation is now abandoning metals in favour of lighter polymers.

Current solutions, Katunin continued, also require expensive repairs after every lightning strike.

To Katunin\'s knowledge, this is the only such research project in Poland. "More teams in Europe, the United States and Japan are working on similar solutions, but each of them has a different approach to the problem. We believe that this solution will be the most competitive for the aviation market" - concluded Katunin. (PAP)

author: Agnieszka Kliks-Pudlik

editor: Anna Ślązak

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