PTAB

IPR2015-01609

Inline Packaging LLC v. Graphic Packaging Intl Inc

Key Events

Petition

petition

Title: MICROWAVE HEATING CONSTRUCT
Brief Description: The ’078 patent describes a paperboard microwaveable heating construct, such as a crisping sleeve, formed from a blank. The construct features a four-paneled sleeve with one open end and one closed end, where the closed end is formed by two overlapping end panels secured by a tab-and-slit closure.

Prior Art Relied Upon: Kato (Japanese Publication No. JP2002-347756) and Clough (Patent 4,948,932).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Kato disclosed all elements of the challenged independent claims except for the "microwave energy interactive material." Kato taught a four-paneled paperboard sleeve for holding hot food, featuring an open end and a closed end formed by two end panels with a tab-and-slit locking feature. Petitioner asserted that Clough, which taught a four-paneled microwave sleeve with an inner layer of microwave interactive material for browning and crisping, supplied the missing element.
- Motivation to Combine: Petitioner contended that a person of ordinary skill in the art (POSA) would combine these references because both relate to paperboard sleeves for heated food. A POSA seeking to adapt Kato’s food container for microwave use would be motivated by the well-known desirability of browning and crisping food to incorporate the microwave interactive material explicitly taught by Clough.
- Expectation of Success: The combination was argued to be a simple substitution of a known element (microwavable material) into a known device (a paperboard sleeve) to yield the predictable result of a microwaveable crisping sleeve.

Prior Art Relied Upon: Kato (Japanese Publication No. JP2002-347756) and Young (Application # 2004/0023000).
Core Argument for this Ground:
- Prior Art Mapping: This ground challenged the "blank" claims, which describe the flat paperboard pattern used to form the construct. Petitioner asserted that Kato’s blank taught most features but configured the seam on a side panel. Young was cited for teaching the use of partial major panels that overlap to form a main bottom panel in a microwave susceptor sleeve, a configuration nearly identical to that claimed in the ’078 patent. Petitioner argued that applying Young’s blank construction to Kato’s container was an obvious design choice.
- Motivation to Combine: A POSA would be motivated to modify the Kato blank to move the seam from the side to the bottom panel, as taught by Young. Petitioner argued this was a known technique to improve heating performance by placing the double-layered seam underneath the food item, which enhances heat conduction and shields the seam from direct microwave radiation, preventing scorching.
- Expectation of Success: A POSA would have a high expectation of success in reconfiguring the panels of the Kato blank according to the established principles taught in Young to create a more effective microwave package, as this involved applying known design modifications to achieve predictable improvements in heating.

Prior Art Relied Upon: Sigel (Application # 2004/0101605) and Kato (Japanese Publication No. JP2002-347756).
Core Argument for this Ground:
- Prior Art Mapping: As an alternative, Petitioner argued that Sigel taught a handheld paperboard package for microwavable sandwiches, including a four-paneled sleeve structure. However, Sigel’s end closure was different. Kato was introduced to supply its specific tab-and-slit end closure with arcuate fold lines.
- Motivation to Combine: A POSA looking to improve the consumer-friendliness of Sigel’s package would look to other packaging designs like Kato. Petitioner argued a POSA would be motivated to replace Sigel's end closure with the more robust and re-closable tab-slit feature from Kato to create a better package.
- Expectation of Success: Implementing Kato's known locking mechanism onto Sigel's sleeve would have been a straightforward modification with predictable results, as it involved combining familiar packaging features.
Additional Grounds: Petitioner asserted additional obviousness challenges, including claims 5, 25, and 30 over Kato, Clough, and Brown I (Patent 4,626,641) to add teachings for trapezoidal tabs; and claims 36, 43, and 50 over Kato, Young, and Brown I. Another combination challenged claims over Kato and Winkelman (Application # 2003/0206997).

"Microwave energy interactive element": Petitioner proposed this term be construed broadly as "any coating, film, or layer of material that 'tends to absorb microwave energy and generate heat'," including susceptors, foils, or combinations thereof, whether continuous or discontinuous. This broad construction was central to the argument that incorporating such a well-known element from the prior art would have been obvious.
"Locking feature" and "cut": Petitioner argued that "locking feature" should be construed as a tab or projection, and "cut" should be construed as coterminous with "slit." This interpretation supported mapping Kato's tab-and-slit closure directly onto the claim limitations.

Seam Placement for Optimal Heating: A central technical argument, particularly for the blank claims, was that a POSA would understand the benefits of placing the overlapping seam of a microwave sleeve on the bottom panel, directly under the food product. Petitioner contended this configuration improves heat transfer to the food and prevents scorching of the seam, providing a strong technical motivation to modify the design of a reference like Kato based on teachings from a reference like Young.

Petitioner requested institution of an inter partes review and cancellation of claims 1-53 of the ’078 patent as unpatentable.