The Federal Circuit recently upheld a summary judgment of noninfringement based on an undisputed claim construction in Plastic Omnium v. Donghee America.
The dispute centered on manufacturing plastic fuel tanks by blow molding. Plastic Omnium is a French automotive supplier specializing in plastics. Donghee America is also an automotive supplier that makes plastic parts for Hyundai and Kia. Plastic Omnium accused Donghee’s manufacturing process of infringing its patents, U.S. Patent Nos. 6,814,921 and 6,866,812.
Donghee’s manufacturing process begins by forcing plastic into a coextrusion head, which extrudes molten plastic with a circular cross-section. Donghee’s product literature labels the plastic at this point a “parison.” The coextrusion head is directly connected to a “flat die” into which the “parison” feeds. Inside the flat die, the plastic is cut and flattened, and the plastic exits the flat die as two flat sheets.
Here is a representative claim that Plastic Omnium accused this process of infringing:
1. A process for manufacturing plastic hollow bodies from two shells formed by molding, which are joined together, at least one shell being produced by compression-molding a portion of a plastic sheet between a mold and a punch and by the remaining portion of the sheet being blow-molded in the region not compression-molded, characterized in that it is applied to the manufacture of a fuel tank and in the sheet is obtained in the same manufacturing line as the shell which will be produced from this sheet, by the cutting and opening an extruded parison of closed cross section.
The dispute centered around the final phrase in the claim, “an extruded parison of closed cross-section.” The district court construed the term to mean “a tubular preform with a closed cross-section that has been forced through a die and is cut or split as it exits the die or at some time thereafter.” The parties did not dispute the construction, and so the Federal Circuit accepted it.
That claim construction was central to the panel’s decision that Donghee did not literally infringe. The panel split, with the majority deciding that the “extruded parison” does not exist at any point of the manufacturing because the plastic is split before exiting the flat die. “The asserted claims require that a tubular parison is first extruded and cut at the point of extrusion or sometime thereafter. In the accused system, the plastic is split and formed within the die, and what is extruded is two formed plastic sheets, not a parison.” The district court’s claim construction decision had stated that “the splitting of the molten plastic must not occur inside any of the extrusion head/die equipment,” which reinforced that the process evaded infringement by splitting the plastic before it exited the flat die.
The panel similarly shot down Plastic Omnium’s doctrine-of-equivalents argument. In essence, Donghee’s process and the process described in the patents led to different results and benefits. The patent cited the uniform thickness of the resulting plastic sheets as a key benefit. Donghee’s process, by contrast, can create two sheets that are intentionally different thicknesses. The panel therefore upheld the district court’s summary judgment of noninfringement.
The dissent did not discuss the doctrine of equivalents, instead objecting to the majority’s decision on literal infringement. According the dissent, the majority assumed that the term “die” in the claim construction necessarily meant Donghee’s flat die. But a jury could reasonably find that the coextrusion head is the “die,” in which case the “extruded parison” limitation is met because the plastic exits from the coextrusion head with a closed cross-section and is cut afterwards in the flat die.
Lessons for Practice
This case shows the importance of thinking a few moves ahead. The claim construction for “extruded parison” was proposed by Plastic Omnium, not Donghee. But that claim construction came back to bite Plastic Omnium because the term “die” was understood to encompass all of Donghee’s apparatus. If the patents could have been used to support broader terminology than “die,” then Plastic Omnium may have been able to get to the jury with its case.