IP Law Daily Claim construction error keeps plastic cling wrap case from wrapping up
News
Thursday, August 4, 2016

Claim construction error keeps plastic cling wrap case from wrapping up

By Peter Reap, J.D., LL.M.

The federal district court in Memphis erred in construing of claims 1 and 28 of the a patent owned by Multilayer Stretch Cling Film Holdings as closed to blends of the four specifically listed resins in the inner layers of the claimed films because the intrinsic evidence of the patent made clear that the Markush group of the four listed resins must be read as open to blends of the four listed resins, the U.S. Court of Appeals for the Federal Circuit has ruled. However, the lower court’s conclusion that the inner layers must be construed as closed to other resins was affirmed. The district court’s conclusion that claim 10 of Multilayer’s asserted patent is invalid was also affirmed, as was the court’s decision not to impose sanctions against Multilayer. The district court’s summary judgment of non-infringement was vacated and the case remanded for further proceedings (Multilayer Stretch Cling Film Holdings, Inc. v. Berry Plastics Corporation, August 4, 2016, Dyk, T.).

Multilayer brought suit against Berry Plastics Corp., alleging infringement of at least claim 1 of U.S. Patent No. 6,265,055 ("the ’055 patent"), which relates to multilayered plastic cling wrap films. The district court held that plastic film products produced by Berry did not infringe the ‘055 patent, finding that the inner layers of all five of Berry’s accused films included blends of resins that did not meet the asserted patent’s closed Markush group limitation.

Multilayer appealed the judgment of non-infringement and the invalidation of claim 10, arguing that the district court erred in its claim constructions. Berry cross-appealed, requesting reversal of the district court’s denial of sanctions under Fed. R. Civ. P. 11.

Most of the language of claim 1 describes the multiple layers of the film and the various types of polymeric "resins"—plastics prepared by polymerization of one or more olefin compounds—that are suitable for use in preparing those layers, the court noted. Claim 1 describes outer layers that contain linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), or ultra low density polyethylene (ULDPE) resins and inner layers that contain these three resins or a fourth resin, metallocene-catalyzed linear low density polyethylene (mLLDPE). Claim 28 is the only other independent claim of the ’055 patent. Like claim 1, claim 28 recites a plastic film that contains at least seven layers, but claim 28 further specifies that at least one of the inner layers must comprise an mLLDPE resin.

The disputed Markush group. The parties disputed the construction of element (b) of claims 1 and 28 of the ’055 patent. The disputed part of element (b) recites, "five [identifiable] inner layers, with each layer being selected from the group consisting of linear low density polyethylene [(LLDPE)], very low density polyethylene [(VLDPE)], ultra low density polyethylene [(ULDPE)], and metallocene-catalyzed linear low density polyethylene [(mLLDPE)] resins." The parties agreed in the district court and agreed on appeal that element (b) of claims 1 and 28 is written in "Markush" claim format. A Markush claim is a particular kind of patent claim that lists alternative species or elements that can be selected as part of the claimed invention, the court explained.

Here, element (b) creates a Markush group that lists four species or types of resin—LLDPE, VLDPE, ULDPE, and mLLDPE—which are understood to be alternately useable for preparing the inner layers of the claimed film. There were two separate issues of claim construction: first, whether the Markush group of element (b) is closed to resins other than the listed four, and, second, whether the Markush group is closed to blends of the four listed resins.

The Markush group is closed to other resins. Multilayer argued that the district court erred and that "[t]he intrinsic evidence clearly establishes that the Markush groups in claims 1 and 28 should be construed as open" to other resins. The appellate court agreed with the district court that the Markush group of element (b) must be construed as closed to resins other than LLDPE, VLDPE, ULDPE, and mLLDPE.

Critical here is that the transitional phrase that appears in element (b), "consisting of," is a term of art in patent law with a distinct and well-established meaning, the Federal Circuit noted. Use of the transitional phrase "consisting of" to set off a patent claim element creates a very strong presumption that that claim element is "closed" and therefore "exclude[s] any elements, steps, or ingredients not specified in the claim." AFG Indus., Inc. v. Cardinal IG Co., Inc., 239 F.3d 1239, 1245 (Fed. Cir. 2001). Thus, if a patent claim recites "a member selected from the group consisting of A, B, and C," the "member" is presumed to be closed to alternative ingredients D, E, and F. The presumption that a claim term set off by the transitional phrase "consisting of" is closed to unrecited elements is at least a century old and has been reaffirmed many times.

Multilayer contended that the specification of the ’055 patent does indeed evince an unmistakable intent to open the Markush group of element (b) to unrecited resins. The appellate court disagreed—the ’055 patent does not manifest a clear intent to open the Markush group of element (b) to LDPE or to any other resin not expressly listed in the claim.

It was true that several passages of the specification of the ’055 patent describe LDPE as a resin suitable for use in both inner and outer layers. However, the listing of these other resins in the specification was not sufficient to overcome the presumption created by the "consisting of" claim language.

Disagreeing with the majority’s claim construction as requiring a layer formed from the listed resins, the dissenting opinion by Judge Taranto argued that a "layer" is an open-ended physical structure "characterized at least by a spatial relationship to some other physical element" and that the "layer" does not "have to be one or more of the listed species" of resin. The dissent’s argument was not made by the patentee in the district court, the majority observed. Indeed, Multilayer argued the very claim construction that the majority now adopted. Multilayer could not now allege that the layers of element (b) of claims 1 and 28 do not have to be "made from" the listed resins, according to the court.

Invalidity of claim 10. Because the appellate court agreed with the district court that the inner layers of claim 1 must be construed as closed to unrecited resins, including LDPE, there was no error in the district court’s conclusion that dependent claim 10 is invalid. Independent claim 1 excludes LDPE from the inner layers, while dependent claim 10 includes it. As such, claim 10 is inconsistent with claim 1 and, indeed, contradicts claim 1. A dependent claim that contradicts, rather than narrows, the claim from which it depends is invalid, the court noted.

The Markush group is open to blends of the four listed resins. The court next considered whether element (b) of claims 1 and 28 is closed to blends of LLDPE, VLDPE, ULDPE, and mLLDPE. The Markush group of element (b) must be construed to permit blends of the four recited resins, the Federal Circuit determined, and the district court erred in ruling otherwise.

By itself, the use of the transitional phrase "consisting of" does not necessarily suggest that a Markush group is closed to mixtures, combinations, or blends. Here, a layer could still "consist" of the listed resins even if the layer "consists" of a mixture of those resins. Nonetheless, the Federal Circuit held in Abbott that there is a presumption that a Markush group is closed to mixtures of the listed elements. Abbott Labs. v. Baxter Pharm. Prods., Inc., 334 F.3d 1274, 1281 (Fed. Cir. 2003). Abbott held that if a Markush claim recites "a member selected from the group consisting of A, B, and C," the claim is presumed to permit the member to be one and only one of A, B, or C, and to exclude mixtures or combinations of A, B, and C. Id.

The district court correctly observed that there is no express language in element (b) permitting "mixtures," "combinations," or "blends" of LLDPE, VLDPE, ULDPE, and mLLDPE. Under Abbott, the Markush group of element (b) is therefore presumed closed to blends. The question became whether that presumption can be overcome by a combination of other claim language and the specification itself, the court reasoned.

Here, the intrinsic evidence of the ’055 patent is unequivocal that the inner layers described in element (b) of claims 1 and 28 are open, not closed, to blends of the recited resins, LLDPE, VLDPE, ULDPE, and mLLDPE, the court ruled. For one, it was clear on its face that the term "linear low density polyethylene" (LLDPE) is one that encompasses at least metallocene-catalyzed linear low density polyethylene (mLLDPE), as mLLDPE is, by its very terms, a subtype of LLDPE prepared with a particular kind of catalyst (metallocenes). Thus, the resins listed in element (b) do not constitute four entirely different species but instead overlap to some extent, the court said. It followed that claims 1 and 28 contemplate the use of polyolefin resins that are classifiable both as an LLDPE and as an mLLDPE, which supports reading element (b) as open to "blending" LLDPE and mLLDPE within a single layer (and open to other blends of the listed resins). Dependent claim 24 also suggests reading element (b) as open to blends, as it recites "[t]he multilayer, thermoplastic stretch wrap film of claim 1, wherein at least one layer comprises a blend of at least two of said resins."

The ’055 patent’s specification similarly supports construing element (b) as open to blends, as it repeatedly and consistently references blends in describing any and all resins, including the four resins of element (b), the court opined. In the light of this strong intrinsic evidence, the Markush group of element (b) must be read as open to blends of the four listed resins, LLDPE, VLDPE, ULDPE, and mLLDPE and this aspect of the lower court’s claim construction was reversed.

Summary judgment. The district court’s grant of summary judgment of non-infringement was predicated on its incorrect construction of claims 1 and 28 as closed to blends of LLDPE, VLDPE, ULDPE, and mLLDPE and it was vacated. Multilayer argued that the district court’s grant of summary judgment of non-infringement was premature. To the contrary, the district court was within its discretion in addressing summary judgment when it did, and there was no reason why the district court should be precluded from entertaining further motions for summary judgment on remand, according to the Federal Circuit.

Sanctions. Berry’s argument that "[t]he District Court abused its discretion by denying Berry’s Motion for sanctions under Fed. R. Civ. P. 11, despite substantial evidence of violations" was without merit, the court determined. This case presented numerous close and difficult questions of claim construction and Berry failed to show that Multilayer’s proffered claim constructions were frivolous. The district court did not abuse its discretion in declining to impose sanctions.

The case is Nos. 2015-1420 and 2015-1477.

Attorneys: Melissa Hunter Smith (Stites & Harbison, PLLC) for Multilayer Stretch Cling Film Holdings, Inc. Mark A. Hagedorn (Barnes & Thornburg LLP) for Berry Plastics Corporation.

Companies: Multilayer Stretch Cling Film Holdings, Inc.; Berry Plastics Corporation

MainStory: TopStory Patent FedCirNews

Back to Top

Interested in submitting an article?

Submit your information to us today!

Learn More