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The patent-at-issue related to multi-layer, thermoplastic stretch wrap films.  The independent claims of the patent included an element of “five identifiable inner layers, with each layer being selected from the group consisting of . . .” five possible layer resin materials.  The district court construed this phrase to require that each of the five inner layers must be composed of only one of the listed resins, which resulted in a grant of summary judgment of non-infringement, because layers in the accused product included blends of the listed resins. 

On appeal, the court made two rulings.  First, it held that this element is a Markush group in which the use of the term “consisting of” creates a “very strong presumption” that the claim element is closed and thus excludes anything not specified in the claimed list of resins.  The court was unpersuaded by Multilayer’s argument that the presence of a dependent claim was sufficient to overcome this presumption, because dependent claims should not “wag the independent claim dog” and, to the extent that the dependent claim conflicts with the closed nature of the independent claim (rather than narrows it), the dependent claim is invalid. 

Second, the court held that, contrary to the district court’s holding, the Markush group element does not exclude a layer that consists of a blend of the listed resins.  Although a Markush group claim is presumed to be closed to blends of the listed elements, that presumption can be overcome by a combination of other claim language and the specification.  Here, the dependent claims and the specification make clear that blends are contemplated and therefore the Markush group is open, not closed, to blends.  Accordingly, the court vacated the summary judgment of non-infringement and remanded to the district court for reconsideration under the correct construction. 

In his dissent, Judge Taranto argues that the court erred by holding that the Markush group is closed to other, non-listed resins.  He argues that the intrinsic evidence (including the dependent claim) is sufficient to overcome the presumption that the claim is closed to other, non-listed resins. 

Multilayer Stretch Cling Film Holdings, Inc. v. Berry Plastics Corporation, Case Nos. 2015-1420, -1477 (August 4, 2016); Opinion by: Dyk, joined by Plager; dissenting opinion by Taranto; Appealed From: United States District Court for the Western District of Tennessee, Young, J.  Read the full opinion here.

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