DuPont Wins Patent Dispute Over Airplane Blankets

Written May 6, 2019

The Court of Appeals for the Federal Circuit on April 17, 2019, affirmed a district court’s ruling that Unifrax I LLC, a global specialty fibers company, infringed DuPont’s patent for materials in thermal-acoustic blankets that are installed in airplanes. E.I. du Pont de Nemours and Company v. Unifrax I LLC, Fed. Cir., No. 17-2575.

The central issue in the appeal centered on claim construction; specifically, the two companies disagreed on the meaning of the term “100% by weight.” To determine the meaning, the Federal Circuit looked at the disclosure of the patent being disputed, as well as the parent of that patent. In a dissent, Judge Kathleen M. O’Malley said the lower court’s decision was "predicated on an erroneous construction” and “introduces more ambiguity than it resolves.”