GKN Aerospace replaces NBR with polyurethane in aircraft fuel bladders

ERJ staff report (DS)

Portsmouth, UK -- Engineers at GKN Aerospace have developed a new fuel bladder for aircraft that is thinner and lighter than conventional rubber bladders, and relies less on adhesives and their VOC emissions.

Frank Bamford, senior vice president of business development and strategy said, “We estimate that use of this material could lead to a 60% reduction in the use of VOCs and a 30 percent reduction in manufacturing times - whilst the weight of each fuel bladder could be reduced by approximately 5 percent through the removal of the adhesive coatings used in traditional bladder construction.”

To provide effective crash resistance of the necessary standard, fuel bladders for the aerospace sector have traditionally been manufactured using multiple layers of composite materials with adhesives joining the bladder to the protective textile layers. This has involved a manufacturing process using solvent-based adhesives and the application of a final lacquer coating to protect the exterior of the fuel bladder.

This innovative new material is manufactured from a thermoplastic polyurethane rather than traditional nitrile rubber and incorporates the reinforcing textile within it. The material also contains an integrated fuel barrier to provide the same level of fuel tolerance exhibited by traditional tanks. This means the crash resistant layer is not applied using adhesives and no final lacquer coating is required, significantly reducing VOC solvent use.

GKN said another environmental benefits from the new tank assembly process include the removal of ozone depleting chemicals that are used in traditional rubber manufacture and the elimination of most fuel tank manufacturing adhesives and the solvents they contain, because the polyurethane basis of the new material will allow the use of radio frequency welding of the tank structure.

This is an external link and should open in a new window. If the window does not appear, please check your pop-up blocking software. ERJ is not responsible for the content of external sites.

Press release from GKN