IP Law Daily Patent for sterilized packaging was unpatentable as obvious
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Tuesday, March 13, 2018

Patent for sterilized packaging was unpatentable as obvious

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

The Patent Trial and Appeal Board, in an inter partes review of a patent owned by Steuben Foods, did not commit reversible error in finding that the challenged claims of the patent were unpatentable as obvious, the U.S. Court of Appeals for the Federal Circuit has decided. Thus, the Board’s decision was affirmed (Steuben Foods, Inc. v. Nestle USA, Inc., March 13, 2018, Hughes, T.).

Steuben Foods owns U.S. Patent No. 6,475,435 B1, directed generally to aseptic packaging, which involves putting a sterile food product into a sterile package within a sterile environment. The ’435 patent is generally directed to providing such a sterile environment in a sterilization tunnel, which is a tunnel pressurized with sterile air to a level above atmospheric pressure. The overpressure creates a flow of sterile air out of the tunnel, ensuring that contaminants cannot flow into it.

Nestle USA, Inc. challenged several claims of the ’435 patent in an inter partes review. The Board instituted trial on claims 1–10, 14, 16–21, 25, 27, 29, and 32–36. The Board found that the challenged claims would have been obvious to a person of ordinary skill in the art in view of prior art references in the record. Steuben Foods appealed.

First, Steuben Foods challenged the Board’s construction of "sterilant concentration levels in the plurality of zones." The Board construed "sterilant concentration levels" to be the levels measured "at any point within the sterilization tunnel—including the ‘residual’ concentration on bottle surfaces—such that the 5 to 1 ratio is satisfied." Steuben Foods contended that the Board construed the term "sterilant concentration levels" so broadly as to read on the concentration of sterilant "at any point" within the sterilization zone, including the concentration of a random droplet on a container. Instead, Steuben Foods argued, the Board should have construed the term as "the amount of sterilant in the volume of pressurized gas within the zone."

Steuben Foods’ proposed construction impermissibly restricts the claim term to a specific embodiment disclosed in the specification, the court determined. While the specification refers to zones with "different concentration levels of gas laden sterilant (e.g., hydrogen peroxide in air)," the specification also refers to residual concentration of hydrogen peroxide on the lids and surface of the bottles.

Steuben Foods failed to point to any language in the claims or disclosure in the specification that supported its position that the claims are limited to the former but specifically excludes the latter. The broadest reasonable construction of "sterilant concentration levels" must, therefore, encompass both the "gas laden" (or "in air") sterilant levels as well as the residual sterilant levels on the lids of the bottles and the bottle surface. Thus, the Board did not err in its construction of the term, the court opined.

Steuben Foods also argued that the Board failed to identify any prior art that discloses maintaining "at least about 5 to 1" (claim 1) or "at least about 1,000 ppm to 0.1 ppm" (claim 3) ratio of sterilant concentration levels in the plurality of zones. The appellate court disagreed and held that substantial evidence supported the Board’s obviousness determination.

Specifically, the Board found that the challenged claims would have been obvious to a person of ordinary skill in the art based on Scholle in view of an FDA regulation, Biewendt (also referred to as the Bosch system), and Elliott, among other prior art references in the record. Both parties agreed that Scholle’s spraying compartment (analogous to the fourth sterilization zone in the ’435 patent) has a higher sterilant concentration than the filling compartment (analogous to the second sterilization zone in the ’435 patent), the court observed. Scholle discloses that the specific concentration of hydrogen peroxide in the spraying zone is around 300,000 ppm, a disclosure that Steuben Foods’ expert, Dr. Sharon, also acknowledged. The Board also credited the testimony of Nestle’s expert. Finally, the Board found that "other prior art aseptic bottling systems recognized the importance of limiting the concentration of [hydrogen peroxide] in the filling zone in order to comply with regulatory limits" of, for instance, no more than 0.5 ppm in the United States, which warrants a "window of operation" for sterilization in the filling compartment in that vicinity. Prior art thus teaches maintaining a ratio of 300,000 ppm over 0.5 ppm in the plurality of zones, which fairly suggests maintaining "at least about 5 to 1" or "at least about 1,000 ppm to 0.1 ppm" ratio of sterilant concentration levels recited in the claims, the court reasoned.

The case is No. 2017-1290.

Attorneys: Thomas Fisher (Oblon, McClelland, Maier & Neustadt, LLP) for Steuben Foods, Inc. Thomas H. Jenkins (Finnegan, Henderson, Farabow, Garrett & Dunner, LLP) for Nestle USA, Inc.

Companies: Steuben Foods, Inc.; Nestle USA, Inc.

MainStory: TopStory Patent FedCirNews

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