IP Law Daily Poly-America’s drawstring trash bag patent not infringed by competitor’s bags
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Friday, October 14, 2016

Poly-America’s drawstring trash bag patent not infringed by competitor’s bags

By Cheryl Beise, J.D.

A federal district court’s narrow construction of the claim term "short seal" in Poly-America’s patent for plastic drawstring trash bags was proper because the patentee had clearly disavowed claim scope in the specification and during prosecution, the U.S. Court of Appeals for the Federal Circuit has decided. Judgment in favor of competitor API Industries was affirmed because API’s accused disposable drawstring trash bags did not meet the asserted patent’s short seals’ inward extension limitation (Poly-America L.P. v. API Industries, Inc., October 14, 2016, Reyna, J.).

Poly-America L.P. owns U.S. Patent No. 8,702,308 (the’308 patent), entitled "Reduced Opening Elastic Drawstring Bag." The patent claims an improved construction of an elastic drawstring trash bag made from two panels of polymeric material joined at the sides and the bottom. The small seals in the relaxed upper corners of the bag, referred to as "short seals," bind together each panel’s hem and the ends of the elastic drawstrings located therein. Independent claims 1 and 16 explicitly provide for a narrowed opening, but independent claim 10 does not. However, claims 12−14, which are dependent on claim 10, provide specific limitations as to the degree of narrowing of the upper opening.

Poly-America sued competitor API Industries, Inc. in 2014 for infringement of at least independent claim 10 of the’308 patent. Finding that the patentee had disavowed claim scope during prosecution, the federal district court in Wilmington, Delaware, construed the claim term "short seal" in claim 10 as "a [a] seal for securing the elastic drawstring, which seal is located adjacent to a side seal, and that is not substantially aligned with the side seal, but extends inwardly from the interior edge of the side seal." The court entered judgment in favor of Poly-America because its accused trash bags did not narrow at the top.

On appeal, Poly-America argued that in construing the term "short seal" to require inward extension, the district court erred by importing limitations from embodiments described in the specification, misreading the prosecution history, and ignoring principles of claim differentiation. None of its arguments was availing.

Claim terms are generally given their ordinary and customary meaning, except when a patentee acts as his own lexicographer or when he clearly and unambiguously disavows the full scope of the claim term in the specification or during prosecution, the court explained.

The specification to the ’308 patent explains that the invention improves on prior art because "the use of extended short seals reduces the claimed bag’s upper opening, making it easy to fit around a trashcan." Moreover, every embodiment described in the specification has inwardly extended short seals and every section of the specification indicates the importance of inwardly extended short seals, the court noted.

During prosecution of the ’308 patent, the examiner twice rejected all of Poly-America’s claims as being obvious over the combination of two prior art patents—Schneider (U.S. Patent No. 7,137,737 B2) and Bonke (U.S. Patent No. 5,133,607 A)—which teach a pull-strip bag with short seals at the upper hem and a plastic liner bag with elastic top, respectively. Poly-America overcame the rejection by distinguishing Schneider from all of the ’308 patent’s independent claims on the basis that Schneider’s short seals were not extended to reduce the bag’s "relaxed upper opening width" in relation to the "bag proper width."

Contrary to Poly-America’s assertion, requiring short seals of less than less than 100% of the bag proper width in claim 10 did not render dependent claim 13—requiring greater than 94% but less than 100% of the bag proper width—redundant. Finally, claim differentiation principles did not preclude importing the narrowing limitation into claim 10. Claim differentiation does not serve to broaden claims beyond their meaning in light of the patent as a whole, and it cannot override clear statements of claim scope found in the specification and prosecution history, the court said.

In view of the ’308 patent’s clear and unequivocal disavowal of claims comprising short seals that do not extend inwardly, the district court’s construction of "short seal" and its judgment in favor of API were affirmed.

The case is No. 2016-1200.

Attorneys: Aaron P. Maurer (Williams & Connolly LLP) for Poly-America L.P. Jack B. Blumenfeld (Morris, Nichols, Arsht & Tunnell LLP) for API Industries, Inc.

Companies: Poly-America L.P.; API Industries, Inc.

MainStory: TopStory Patent FedCirNews

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