Viskase Cos., Inc. v. World Pac Int’l. AG, No. 09 C 5022, Slip Op. (N.D. Ill. Aug. 9, 2010) (Bucklo, J.).

Judge Bucklo denied defendants’ motion for preliminary injunction based upon World Pac’s patent infringement counterclaim regarding impermeable sausage casings. Viskase’s research and design documents referenced "World Pac knock-off[s]," "World Pac replacement[s]" and "World Pac me-too" products. The key infringement issue was whether Viskase’s accused casings were "impermeable" as that term was construed by the Court. The parties set up a "classic battle of the experts" with competing testing disputing whether the accused sausage casing allowed a measurable weight loss, and therefore was permeable. While a jury would ultimately have to weigh the evidence, Viskase presented "more than insubstantial evidence" that the accused casings lost measurable weight. And Viskase’s testing was done outside of litigation, lending it additional credibility. World Pac also failed to present sufficient evidence regarding loss of flavor and taste, the other "impermeable" characteristics. Viskase, therefore, raised a substantial noninfringement question. Furthermore, World Pac did not put forth sufficient evidence to warrant a preliminary injunction. Because Viskase raised a substantial question regarding noninfringement, the Court declined to examine Viskase’s other defenses or the other element of a preliminary injunction.