United States Court of Appeals 

for the Federal Circuit ______________________

PLASTIC OMNIUM ADVANCED INNOVATION AND 

RESEARCH,

Plaintiff-Appellant

v.

DONGHEE AMERICA, INC., DONGHEE ALABAMA, 

LLC,

Defendants-Appellees

______________________

2018-2087

______________________

Appeal from the United States District Court for the 

District of Delaware in No. 1:16-cv-00187-LPS, Chief Judge 

Leonard P. Stark.

______________________

SEALED OPINION ISSUED: November 21, 2019

PUBLIC OPINION ISSUED: December 3, 2019*

______________________

ALEXANDER HADJIS, Oblon, McClelland, Maier and 

Neustadt, LLP, Alexandria, VA, argued for plaintiff-appellant. Also represented by ROBERT CARTER MATTSON,

CHRISTOPHER RICCIUTI. 

 

* This opinion was originally filed under seal and has 

been unsealed in full.
2 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

 ERIC SHUMSKY, Orrick, Herrington & Sutcliffe LLP, 

Washington, DC, argued for defendants-appellees. Also 

represented by MELANIE L. BOSTWICK, JEREMY PETERMAN; 

ALYSSA MARGARET CARIDIS, Los Angeles, CA; EDMUND 

HIRSCHFELD, New York, NY. 

 ______________________

Before NEWMAN, CLEVENGER, and REYNA, Circuit Judges.

Opinion for the court filed by Circuit Judge REYNA.

Dissenting opinion filed by Circuit Judge CLEVENGER.

REYNA, Circuit Judge. 

Plastic Omnium Advanced Innovation and Research 

appeals from a grant of summary judgment of noninfringement by the U.S. District Court for the District of Delaware. The district court’s determinations on summary 

judgment are consistent with its claim construction and 

supported by undisputed facts in the record. We affirm.

BACKGROUND

A. The Asserted Patents

Plastic Omnium Advanced Innovation and Research

(“Plastic Omnium”) owns U.S. Patent Nos. 6,814,921 (“the 

’921 patent”) and 6,866,812 (“the ’812 patent”). The patents generally relate to manufacturing plastic fuel tanks 

formed by blow molding. The fuel tanks are formed in a 

way that allows accessory components to be installed inside the fuel tank without cutting holes in the tank wall, 

which could compromise the structural integrity of the 

wall. A conventional blow molding system is depicted below:
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 3

J.A. 3482 (Appellee’s Technology Tutorial). The image 

shows the general placement and geometry of the extruder 

head, die, parison, and molding cavity in a conventional 

blow molding process. 

The sole figure (shown below) of the ’812 patent is representative of the disclosed system and depicts a tubular 

“parison” that is formed using an extrusion head (component 2) and circular die mounted on the extrusion head. As 

the parison exits the extrusion head, a blade (component 3) 

located at the exit of the die splits the parison. 
4 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

’812 patent Fig. 1, col. 5 ll. 28–30; see also ’921 patent

col. 5 l. 25.

Claim 1 of the ’921 patent recites the following, including the disputed “extruded parison” limitation:

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.
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 5

’921 patent col. 5 l. 44–col. 6 l. 6 (emphasis added to disputed term). Claim 32 of the ’812 patent includes a similar 

disputed term: “extruding a parison.”

B. District Court Proceedings

On March 23, 2016, Plastic Omnium filed suit against 

Donghee America, Inc., and Donghee Alabama, LLC (collectively “Donghee”) in the District of Delaware, asserting 

infringement of several patents. The ’921 and ’812 patents 

were among the eight patents in Plastic Omnium’s 

amended complaint. After claim construction, Donghee 

moved for summary judgment of noninfringement as to the 

asserted claims of the ’921 and ’812 patents and on other 

bases not at issue in this appeal. On May 22, 2018, the 

district court granted Donghee’s summary judgment motion. The district court entered final judgment on June 11, 

2018.

1. Claim Construction

During claim construction, the parties disputed the 

meaning of the term “parison.” Plastic Omnium Advanced 

Innovation & Research v. Donghee Am., Inc., No. 16-CV187, 2017 WL 5125725, at *3–4 (D. Del. Nov. 6, 2017)

(“Claim Construction Order”). Donghee argued that it 

should be given its plain and ordinary meaning of “hollow 

plastic tube exiting the die of an extrusion head.” Id. at *3.

Plastic Omnium argued that the patentee had acted as its 

own lexicographer and that “the ’921 and ’812 patents do 

not use the term ‘parison’ [in] its conventional, plain and 

ordinary meaning.” Id. The district court agreed with 

Plastic Omnium and reasoned that “the patents specify 

that the ‘parison’ is cut in two as it leaves the die at the end 

of the extrusion head” and so “this ‘parison’ cannot be 

strictly limited to a fully-formed tubular structure existing 

in its entirety outside the extrusion head/die.” Id. at *4. It 

recognized that “the principal disagreements between the 

parties [were] identifying the point at which the molten 

plastic within the extrusion head becomes a ‘parison,’ and 
6 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

identifying the location of the die.” Id. The district court 

rejected Plastic Omnium’s contention that the “claimed 

process includes the splitting of molten plastic within the 

extrusion head/die” based on its determination that neither 

specification discloses “splitting of the tubular preform at 

any stage earlier than right as the previously tubular 

structure leaves the die/extrusion head.” Id. (internal quotations omitted). The district court also clarified that “the 

‘extruded parison’ terms should not include molten plastic 

(or a tubular preform) present inside the die/extrusion 

head and that the “‘die’ is located at the ‘extrusion head[’s]’

‘lowest point,’” rejecting Plastic Omnium’s contention that 

the “die” could be located anywhere. Id. at *4, *4 n.4 (quoting ’921 patent col. 3 ll. 4–5; ’812 patent col. 2 ll. 37–38). 

Accordingly, the district court construed “parison” as “referring to a plastic tube with a closed cross section that is 

shaped by—and has reached the end of—a die and is split 

either immediately upon exiting the die or at some point 

thereafter.” Id. at *4. Building upon that construction, the 

district court construed “extruded parison of closed cross 

section” and “extruding a [multilayered] parison” as “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” and “a [multilayered] 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,” respectively. Id. at *8 (alterations in original). 

2. Summary Judgment

Donghee moved for summary judgment of noninfringement of five asserted patents, including the ’921 and ’812 

patents involved in this appeal.1 Donghee argued that its 

 

1 This appeal also included U.S. Patent Nos. 

7,166,253 and 9,399,327. Plastic Omnium filed a Motion to 

Withdraw those patents from this appeal which we grant 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 7

accused product does not infringe the asserted claims of the 

’921 and ’812 patents because it “does not extrude a parison.” Plastic Omnium Advanced Innovation & Research v. 

Donghee Am., Inc., 387 F. Supp. 3d 404, 416–17 (D. Del. 

2018) (“Summary Judgment Order”). Relying on its claim 

construction of the “parison” terms, the district court 

granted summary judgment of noninfringement. Id. 

As to literal infringement, the district court recognized 

that there was no dispute that Donghee’s “‘manufacturing 

process begins by forcing plastic through a circular coextrusion head, and then feeding the plastic that exits the 

coextrusion head into a separate piece of equipment, referred to as a flat die tool,’ and that once inside ‘the flat die, 

the molten plastic is cut into two streams of plastic which 

are extruded as two sheets.’” Id. at 416 (citing Donghee’s 

brief in support of its motion for summary judgment and 

Plastic Omnium’s brief in opposition). Turning to its claim 

construction holdings, the district court reiterated its determinations that (1) “parison” was not limited to a fully 

formed tubular structure that exists entirely outside of the 

extrusion head/die, i.e., the “parison” may be cut as it exits 

the die at the end of the extrusion head; (2) the tubular 

preform cannot be split at any stage prior to its exit of the 

extrusion head/die such that molten plastic or a tubular 

preform present inside the extrusion head/die is excluded 

from the claim scope; and (3) the die must be located at the 

extrusion head’s lowest point. Id. (citing Claim Construction Order, 2017 WL 5125725, at *4). 

According to the district court, “[b]ecause the splitting 

does not occur ‘at any stage earlier than right as the previously tubular structure leaves the die/extrusion head,’ the 

claim construction makes clear that whether the extrusion 

equipment consists of a single combined extrusion head 

 

(see Conclusion) and therefore do not address those patents 

in the Background. 
8 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

with a die or a more complex extrusion head with a separate attached die, the splitting of the molten plastic must 

not occur inside any of the extrusion head/die equipment.” 

Id. (internal citation omitted and emphases added). Quoting Plastic Omnium’s brief in opposition of summary judgment, the district court found that there was no genuine 

dispute of material fact that Donghee’s accused product 

does not literally infringe because “for the accused product, 

it is undisputed that ‘[t]he extruded plastic parison is [ ] 

cut in a separate “flat die” tool after it leaves Donghee’s 

coextrusion die.’” Id. (omissions and alterations in original).

The district court also concluded that Donghee’s accused product did not infringe under the doctrine of equivalents. According to the district court, “a reasonable jury 

could not find [that the] cutting [of] the parison while it is 

extruding within extrusion equipment is insubstantially 

different than [the] cutting [of] the extruded parison outside the extrusion equipment.” Id. at 417. The district 

court also pointed to statements by Dr. Osswald, Plastic 

Omnium’s expert, where he acknowledged differences between Donghee’s “flat die tool” and the claimed invention. 

Id. (citing J.A. 387; 431).

Plastic Omnium appeals. We have jurisdiction under 

28 U.S.C. § 1295(a)(1). 

DISCUSSION

We review a grant of summary judgment under the law 

of the applicable regional circuit, here the Third Circuit. 

ArcelorMittal Atlantique et Lorraine v. AK Steel Corp., 908 

F.3d 1267, 1273 (Fed. Cir. 2018). The Third Circuit reviews

a grant of summary judgment de novo. Gonzalez v. Sec’y of 

Dep’t of Homeland Sec., 678 F.3d 254, 257 (3d Cir. 2012).

Plastic Omnium challenges the district court’s grant of 

summary judgment of no literal infringement and no 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 9

infringement under the doctrine of equivalents as to the 

’921 and ’812 patents. We address each argument in turn.

A. Literal Infringement

Plastic Omnium argues that the court granted summary judgment based on an erroneous claim construction. 

Appellant Br. 32. According to Plastic Omnium, the district court’s summary judgment improperly imposed a “cutting location requirement.” Id. at 35. We disagree.

We first note that despite its argument that summary 

judgment was based on an erroneous claim construction, 

Plastic Omnium does not dispute the district court’s construction of “extruded parison of closed cross section” as “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.” Nor does it dispute the construction of “extruding a [multilayered] parison” as “a [multilayered] 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.” Rather, Plastic Omnium argues that the district court erred by deviating from 

its claim construction order and requiring “the claimed parison to be cut or split outside of the extrusion equipment.” 

Id. We therefore determine whether the correct application of the district court’s claim construction excludes the 

accused Donghee product based on the undisputed facts. 

We conclude that it does.

Claim 1 of the ’921 patent requires “cutting and opening of an extruded parison of closed cross section.” ’921 patent col. 5 l. 44–col. 6 l. 5 (emphasis added). Claim 32 of 

the ’812 patent requires “extruding a parison” and then 

“cutting through said parison so as to form two portions 

separated by a cut . . . .” ’812 patent col. 7 ll. 14–18 (emphasis added). In construing the “parison” terms, the district court made clear that “extruded parison [] should not

include molten plastic (or a tubular preform) [] inside the 

die [or] extrusion head” and that the “‘die’ is located at the 
10 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

‘extrusion head[’s]’ ‘lowest point.’” Claim Construction Order, 2017 WL 5125725 at *4, *4 n.4. Thus, no “extruded

parison” is formed until a plastic tube, which implies some 

depth, of a closed cross section passes through and exits the 

die located at the lowest point of the extrusion head. The 

district court rejected Plastic Omnium’s contention that 

the claims included splitting plastic inside the extrusion 

head or die and its contention that the die could be located 

anywhere in the extrusion equipment. See id. at *4.

The district court’s determination on summary judgment is consistent with its Claim Construction Order. The 

district court first recognized two undisputed facts about 

Donghee’s process: (1) the process begins with forcing plastic into a “coextrusion head” and then feeding the plastic 

into a separate “flat extrusion die;” and (2) “once inside the 

flat die, the molten plastic is cut into two streams of plastic 

which are extruded as two sheets.” Summary Judgment 

Order, 387 F. Supp. 3d at 416–17 (internal quotations omitted). In view of its Claim Construction Order, the district 

court determined that regardless of Plastic Omnium’s argument that the “coextrusion head” was itself a “die,” the

claim construction “makes clear” that “the splitting of the 

molten plastic must not occur inside any of the extrusion 

head/die equipment.” Id. (emphasis added). In other 

words, the claims require that the extruded parison is split 

after passing through the extrusion head and die. 

It is undisputed that Donghee’s accused product is

manufactured by a process where two separate plastic 

sheets are extruded from the die located at the lowest point 

of the extrusion head using what is referred to as a “flat die 

system.” Appellant Br. 40 (citing J.A. 710–11, 736–38, 

784); see also id. at 19–20. The flat die does not produce an 

extruded parison as required by the claims, but two 

separate plastic sheets, which are not cut at the point of 

exiting the die or thereafter. Instead, in the accused 

system, molten plastic is injected directly from the 

extrusion head into the die mounted directly on the 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 11

extrusion head where it is split into two sheets and formed 

in the die as shown in the images below.

J.A. 451. 

As seen in the images, Donghee’s own product 

literature refers to the plastic entering the flat die tool as 

a “parison.” But the district court correctly determined in 

its claim construction—accepting Plastic Omnium’s 

arguments—that the patentee gave the term “parison” a 

special definition, and the patents “do not use the term 

‘parison’ [in] its conventional, plain and ordinary 

meaning.” Claim Construction Order, 2017 WL 5125725, 

at *4. Thus, the patentee’s definition of “parison” in the 

specification and as construed by the court—not Donghee’s 
12 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 

product literature—controls whether the accused product 

falls withing the scope of the claim. See Martek Biosciences 

Corp. v. Nutrinova, Inc., 579 F.3d 1363, 1380 (Fed. Cir. 

2009); see also Phillips v. AWH Corp., 415 F.3d 1303, 1316 

(Fed. Cir. 2005) (en banc) (“[O]ur cases recognize that the 

specification may reveal a special definition given to a 

claim term by the patentee that differs from the meaning 

it would otherwise possess. In such cases, the inventor’s 

lexicography governs.”). Thus, despite the fact that 

Donghee’s product literature uses the term “parison” to 

refer to plastic at the inlet of the flat die, it does not depict 

that an “extruded parison” as defined by the patentee 

acting as its own lexicographer and construed by the 

district court has formed at that point. Donghee’s product 

literature does not show a tubular structure as required by 

the Claim Construction Order. And as noted above, it is 

undisputed that the plastic passing into the flat die is 

molten, which the Claim Construction Order specifically 

excludes. 

Plastic Omnium argues that the district court’s 

quotation of its brief in opposition to summary judgment 

shows that the district court concluded that there was no 

dispute that an “extruded plastic parison” exits Donghee’s 

“coextrusion die.” See, e.g., Appellant Br. 38; Oral 

Argument at 3:55–4:31, available at 

http://www.cafc.uscourts.gov/oral-argument-recordings

(citing J.A. 20). This argument is contrary to the record 

because, at oral argument, Donghee disputed Plastic 

Omnium’s contention. See Oral Argument at 45:56–47:09. 

The district court recognized that the heart of the dispute 

was whether a parison is extruded at all: “Donghee argues 

that the accused product does not infringe the Parison 

Claims because it does not extrude a parison.” Summary 

Judgment Order, 387 F. Supp. 3d at 416 (footnote removed)

(emphasis added). The district court further characterized 

“the parties’ dispute [as] center[ing] on whether (1) the first 

piece of equipment, the ‘coextrusion head,’ is or has a die, 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 13

and (2) the extruded parison may continue to be located in 

the second piece of equipement, the ‘flat die,’ and still be 

held to infringe.” Id. (internal citations removed). 

Further, the district court’s Claim Construction Order also 

recognized that “the principal disagreements between the 

parties seem to be identifying the point at which the molten 

plastic within the extrusion head becomes a ‘parison,’ and 

identifying the location of the die.” Claim Construction 

Order, 2017 WL 5125725, at *4. 

We are thus not persuaded by Plastic Omnium’s 

contention that the district court’s citation and quoation of 

Plastic Omnium’s opposition brief shows that the district 

court determined that it was undisputed that an “extruded 

parison” leaves the “coextrusion die.” The district court 

understood that the claims require a parison to be extruded 

from a die located at the lowest point of the extrusion 

equipment and that the splitting of the plastic must not 

occur inside the die. See Summary Judgment Order, 387 

F. Supp. 3d at 416 (“[T]he claim construction makes clear 

that whether the extrusion equipment consists of a single 

combined extrusion head with a die or a more complex 

extrusion head with a separate attached die, the splitting 

of the molten plastic must not occur inside any of the 

extrusion head/die equipment.” (emphasis added)).

Plastic Omnium’s arguments rely heavily on recasting

the “coextrusion head” in the accused system as a “coextrusion die,” and Plastic Omnium contends that the plastic 

melt flowing from the extrusion head and directly into the 

flat die satisfies the extruded parison limitation. Appellant 

Br. 40. But “extrusion head” and “die” as used in the asserted patents are distinct terms. E.g., ’812 patent col. 2 

ll. 35–38 (stating “an extruder whose head is terminated by 

the die”); id at col. 2 ll. 46–48 (“In accordance with the process according to the invention, at least one cut is made in 

the parison leaving the die mounted on the extrusion 

head.”); id. col. 5 ll. 23–30 (“The tubular multilayer extrudate (1) . . . leaves the extrusion head (2) and is separated 
14 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

into two sheets (1), using two steel blades (3) placed at 180 ̊ 

to each other, at the exit of the circular die mounted on the 

extrusion head (2).”); ’921 patent col. 3 ll. 2–5 (“One example is that of a sheet produced by extrusion, in an extruder 

placed vertically, the extrusion head which includes the die 

being located at the lowest point.”). The court’s claim construction order similarly uses “extrusion head” and “die” as 

distinct terms. Claim Construction Order, 2017 WL 

5125725, at *3–4 (“[T]he patents specify that the ‘parison’

is cut in two as it leaves the die at the end of the extrusion 

head.”). Thus, the claims require that the extrusion head 

and die are distinct components that the “parison” must 

pass through before it is split. 

Dr. Osswald admitted that the patents disclose that 

there is “a die mounted on the extrusion head” but still took 

the position that there is actually no die mounted on “an 

extrusion head or a co-extrusion die or a co-extrusion head, 

whatever you want to call it.” J.A. 1926 (Osswald Dep. Tr. 

151:11–152:15.). He justified the apparent contradiction of 

his position by asserting that the language of the patents 

“may just be a poor choice of words.” Id. He thus cited no 

contrary evidence and merely speculated that the die is not 

a separate part mounted on the extrusion head in the patents. 

Dr. Osswald also asserted that “if there’s nothing that 

comes after [the extrusion head in Donghee’s accused product], you extrude a tube or tubular parison.” J.A. 1926 

(Osswald Dep. Tr. 151:18–20) (emphasis added). Plastic 

Omnium argues that this testimony demonstrates that the 

accused product satisfies the extruded parison limitation. 

It is undisputed, however, that in Donghee’s accused product, the “flat die” comes after the extrusion head. See J.A. 

262 (“Donghee’s process utilizes a separate ‘flat die tool’ 

that forms two sheets of plastic . . . .”). The flat die is 

mounted directly on the extrusion head, and thus no tube 

or tubular parison is extruded from the extrusion head. 

That molten plastic may pass through a “spiral mandrel” 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 15

in the bottom of the extrusion head as it passes directly into 

and is split within the flat die is not sufficient. Donghee’s 

system thus does not satisfy the “extruded parison” limitation under the district court’s claim construction. 

In summary, Donghee’s accused product is different 

from the claimed system. 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. Accordingly, we affirm the district court’s grant of summary 

judgment of no literal infringement. 

B. Infringement Under the Doctrine of Equivalents

Plastic Omnium argues that the district court erred in 

granting summary judgment of noninfringement under the 

doctrine of equivalents by improperly reading in a cutting 

location requirement and ignoring that the steps in the 

claimed process and in the accused product are the same 

no matter where the splitting of the parison occurs. Appellant Br. 41–42. 

“A finding of infringement under the doctrine of equivalents requires a showing that the difference between the 

claimed invention and the accused product or method was 

insubstantial or that the accused product or method performs the substantially same function in substantially the 

same way with substantially the same result as each claim 

limitation of the patented product or method.” AquaTex 

Indus., Inc. v. Techniche Sols., 479 F.3d 1320, 1326 (Fed. 

Cir. 2007). “The function, way, result inquiry focuses on an 

examination of the claim and the explanation of it found in 

the written description of the patent.” Id. (internal quotations omitted).

While the district court provided little analysis or support as to its determination of no infringement under the 

doctrine of equivalents, “we review judgments, not 
16 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

opinions.” Bruno Indep. Living Aids, Inc. v. Acorn Mobility 

Servs., Ltd., 394 F.3d 1348, 1354 (Fed. Cir. 2005) (citing 

Black v. Cutter Labs., 351 U.S. 292, 297 (1956)). We must 

therefore determine whether the record supports the district court’s determination that no reasonable jury could 

find that Donghee’s accused product infringes under the 

doctrine of equivalents. 

The district court’s limited citations to the record include a report and testimony from Dr. Osswald admitting 

that “Donghee’s flat die tool may offer improvements (e.g., 

independent wall thickness manipulation) over the blade 

and roller cutting system of the Asserted Patents.” J.A. 387 

¶ 36; see also J.A. 430–31 (“Q: So I believe in your reply 

report you believe that Donghee’s flat die would offer some 

improvements over cutting -- over other methods of cutting 

where you maybe have a knife . . . A: Well, I mean, I say it 

right there. Like, independent wall thickness manipulation. That’s one.”). Further, Dr. Osswald referred to this

ability to control the wall thickness as “an invention” distinct from the asserted patents. J.A. 431. 

As such, Dr. Osswald conceded that Donghee’s products differed from the patented invention because 

Donghee’s process allowed for the advantageous capability 

of independent wall thickness manipulation resulting from 

the way plastic is split. The question is whether Plastic 

Omnium presented evidence that this conceded advantage

is an “insubstantial difference.” AquaTex Indus., 479 F.3d 

at 1328 (quoting Texas Instruments, Inc. v. Cypress Semiconductor Corp., 90 F.3d 1558, 1567 (Fed. Cir. 1996)). 

Plastic Omnium’s arguments and the patents’ written 

descriptions tout uniform wall thickness as a feature of the 

patents. In its opening brief, Plastic Omnium states that 

its inventions “avoid[] the prior ‘drawback of having to position two extrusion heads and/or extruders capable of simultaneously producing two flat sheets, the thickness 

uniformity and the production uniformity of which are 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 17

[required to be] constant from one sheet to another and at 

any point on each of the sheets.’” Appellant Br. 11 (quoting 

the ’812 patent col. 1 ll. 42–46) (emphasis added). Dr. 

Osswald conceded that, in contrast, independent wall 

thickness manipulation is an advantage of the Donghee 

system. Plastic Omnium failed to present evidence as to 

why the differences between the touted advantage of uniform wall thickness in the ’812 and ’921 patents and the

capability of independent wall thickness manipulation in

the accused product were insubstantial. See Appellant Br. 

41–42; Appellant Reply Br. 22–23. Plastic Omnium therefore failed to demonstrate a genuine dispute of material 

fact that would prevent the grant of summary judgment as 

to the doctrine of equivalents. 

CONCLUSION

The district court’s grant of summary judgment of no

literal infringement was consistent with its Claim Construction Order based on undisputed differences between 

the asserted patents and the accused product. The district 

court’s grant of summary judgment of no infringement under the doctrine of equivalents was correct in light of the 

conceded differences between the claimed process in the asserted patents and process of the accused product. Because 

we affirm based on the “parison” limitations, we need not 

reach the issue of whether Plastic Omnium preserved the 

“preassembled structure” claim construction issue concerning the ’812 patent. We grant Plastic Omnium’s pending 

Motion to Withdraw U.S. Patent Nos. 7,166,253 and 

9,399,327 (ECF No. 47). 

AFFIRMED

COSTS

Each party shall bear its own costs. 
United States Court of Appeals 

for the Federal Circuit ______________________

PLASTIC OMNIUM ADVANCED INNOVATION AND 

RESEARCH,

Plaintiff-Appellant

v.

DONGHEE AMERICA, INC., DONGHEE ALABAMA, 

LLC,

Defendants-Appellees

______________________

2018-2087

______________________

Appeal from the United States District Court for the 

District of Delaware in No. 1:16-cv-00187-LPS, Chief Judge 

Leonard P. Stark.

______________________

CLEVENGER, Circuit Judge, dissenting.

The majority frames the parties’ dispute as one focused 

on the meaning of the term “extruded parison.” The majority concludes, as the district court did, that such a dispute 

cannot preclude summary judgment because the patentee

acted as his own lexicographer when he defined the term 

“extruded parison” in one of the asserted patent specifications. According to the majority, the district court correctly 

construed the term in accordance with the patentee’s definition, and then simply applied that construction to the accused device, which did not include the claimed parison. To 

both the district court and the majority, the claimed extruded parison cannot exist in Donghee’s process because 
2 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

the plastic is cut inside of a “die,” contravening the district 

court’s construction. But by blessing the district court’s 

analysis, the majority commits the same error. Both rely 

on Donghee’s nomenclature—the fact that its cutting structure is called a “die”—to find no infringement. That analysis elides the key factual dispute: Does Donghee’s accused 

process have more than one die? The real dispute therefore 

is not over an extruded parison and what it takes to create 

one—in fact, the parties agree on that front—but is instead 

over the term “die” and whether Donghee’s extrusion head 

contains one. Plastic Omnium presented sufficient evidence to create a material factual dispute over the structure of Donghee’s extrusion head, and I therefore

respectfully dissent from the majority’s decision.

I

The patents at issue in this case claim an improvement 

on the standard manufacturing process used to create plastic motor-vehicle fuel tanks. U.S. Patent No. 6,866,812 

(“the ’812 patent”), Abstract (“Process for manufacturing 

hollow plastic bodies, especially motor-vehicle fuel tanks.”); 

U.S. Patent No. 6,814,921 (“the ’921 patent), Abstract 

(“Process for manufacturing a plastic fuel tank.”). Specifically, claim 1 of the ’812 patent discloses in relevant part 

“[a] process of manufacturing a hollow body for receiving a 

liquid, comprising the steps of: extruding a parison; cutting 

through said parison so as to form two portions separated 

by a cut . . . .” ’812 patent, col. 5, ll. 43–47. Claim 1 of the 

’921 patent similarly recites in relevant part:

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

. . . 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 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 3

will be produced from this sheet, by the cutting and 

opening an extruded parison of closed cross section. 

’921 patent, col. 5 ll. 44–col. 6 ll. 5. 

The patentee defined the term “extruded parison” in 

the ’812 patent as “the product obtained by passing, 

through a die, a composition of at least one thermoplastic 

melt homogenized in an extruder whose head is terminated 

by the die.” ’812 patent, col. 2, ll. 35–40. In its Markman 

order, the district court construed “extruded parison” consistent with the ’812 patent’s definition as “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.” J.A. 946. The district court explained further that, while the claimed process could not 

“include[] the splitting of molten plastic within the extrusion head/die,” splitting could occur “right as the previously 

tubular structure leaves the die/extrusion head.” J.A. 948. 

The district court was never asked to construe the “die” 

term, but in its Markman order, the district court disagreed with Plastic Omnium’s argument that the parisoncreating die could be located anywhere within the extrusion head because “[b]oth patents specify that the ‘die’ is 

located at the ‘extrusion head[’s] lowest point.” J.A. 948 n.4 

(quoting ’921 patent, col. 3, ll. 4–5). 

Besides the location of the die as either “mounted on 

the extrusion head,” “located at the lowest point” of “the 

extrusion head,” ’921 patent, col. 3, ll. 4–5, or being what 

“terminate[s]” the head of the extruder, ’812 patent, col. 2, 

ll. 37–38, the specification is mostly silent on its structure 

and function. The specifications of both the ’921 and ’812 

patents do, however, describe the die as “circular.” ’921 patent, col. 3, ll. 4–5. 

II

By the Markman hearing, Plastic Omnium was already 

teeing up its argument that, in addition to Donghee’s flat 
4 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

die tool, Donghee’s process involved another die at the bottom of its extrusion head, or “coextrusion die tool,” as 

Donghee refers to it in its literature. J.A. 711. During the 

hearing, Plastic Omnium told the district court judge “[i]t 

probably bears mentioning, I don’t know if it was apparent 

in the briefing what the real dispute is between the parties 

here, and I think what Donghee may say is they don’t have 

a circular die. I think that’s where the dispute is going to 

be.” J.A. 1523. 

Then, in its summary judgment briefing, Plastic Omnium supported its argument with its expert report that 

identified the relevant die at the bottom of Donghee’s coextrusion die tool:

The coextrusion die’s bottom includes the spiral 

mandrel and an outer body that surrounds the spiral mandrel, which together define an annular 

channel through which the extruded materials are 

forced to obtain the tubular preform. The structure 

that forms this annular channel, through which 

the molten material is forced before exiting the bottom of the coextrusion die, is a “die” as that term is 

used in general and as it is used in the asserted Patents.

J.A. 264. Plastic Omnium’s expert made clear that he was 

not “argu[ing] that some amorphous melt inside of 

Donghee’s extrusion equipment is a parison.” J.A. 383. Instead, he was arguing that a parison is the tubular preform 

created by the die at the bottom of Donghee’s coextrusion 

die tool, which is fed into Donghee’s flat die tool, where the 

extruded parison is cut. Id.

Plastic Omnium also pointed the district court to 

Donghee’s own documentation, which stated that the “inlet” to its flat die tool is a “round 6-layers [sic] parison,” and 

that the flat die tool functions to “cut[] . . . the parison in 

two halves.” J.A. 738. Thus, Plastic Omnium’s argument 

all along was that Donghee’s flat die tool is essentially 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 5

irrelevant to the infringement analysis. What mattered, 

Plastic Omnium explained, was that Donghee’s extrusion 

head included a parison-creating die at its terminus, and 

therefore “the plastic exiting Donghee’s coextrusion die 

(with the spiral mandrel), and which is fed into the flat die 

tool, is the claimed parison.” J.A. 383. Because the claimed 

parison is formed in Donghee’s process and cut thereafter, 

Plastic Omnium argued that Donghee clearly infringed the 

claims of the ’812 and ’921 patents, as construed by the district court.

In its summary judgment opinion, the district court

clearly recognized that there was a dispute over whether

Donghee’s coextrusion head “is or has a die.” J.A. 19. Yet, 

it granted summary judgment of noninfringement without

ever considering Plastic Omnium’s double-die argument. 

It reasoned that there can be no literal infringement because “the splitting of the molten plastic must not occur inside any of the extrusion head/die equipment,” and it was 

“undisputed that the extruded plastic parison is [] cut in a 

separate flat die tool after it leaves Donghee’s coextrusion 

die.” J.A. 20 (internal quotation marks omitted). 

The error that the district court committed, and that 

the majority approves, stems from the assumption that the 

relevant die for purposes of infringement is Donghee’s flat 

die tool. Both rely on Donghee’s chosen nomenclature for 

its cutting tool, i.e., “flat die tool,” to find that Donghee’s 

process involves cutting molten plastic inside of a “die,” instead of upon or after extrusion from the “die.” Because the 

claims require cutting a parison, and a parison cannot be 

cut before it is formed by being forced through a die, the 

district court and the majority believe that there cannot exist the claimed parison in Donghee’s process. But just because Donghee calls its cutting tool a “die” does not mean 

it is the relevant die for purposes of the infringement analysis. 
6 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

The only die that matters under the district court’s construction of “extruded parison” is the die through which the 

plastic is forced to form a parison. The district court’s construction never required that such a die be the only die in 

the process or the last die in the process. The fact that the 

district court’s construction does not contemplate splitting 

the tubular preform before it is at least partially extruded 

from a die at the end of an extrusion head does not support 

the broader conclusion, adopted by the majority, that the 

patents require the tubular preform to be partially extruded outside of all of the extrusion equipment, including 

Donghee’s flat die tool, before being cut. Thus, if Plastic 

Omnium is correct that Donghee’s accused process includes 

an extrusion head that is terminated by a die, then such a 

structure, under the court’s construction, would be sufficient to create the claimed parison. Further, that parison 

would be split by the flat die tool, which is outside of the 

relevant extrusion head/die equipment, in keeping with the 

district court’s construction.

The majority discredits the evidence in support of Plastic Omnium’s double die theory by relying on the fact that 

the patentee acted as his own lexicographer when using the 

“parison” term. According to the majority, the fact that 

Donghee’s documentation refers to the plastic extruded 

from Donghee’s extrusion head as a “parison” does not 

mean that Donghee intended to use that word as it is used 

in the patents. But the majority misunderstands how the 

patentee changed the meaning of “parison” by defining it 

in the ’812 specification. 

There was no disagreement between the parties here 

that the “ordinary and customary” meaning of “parison” is 

“a hollow plastic tube exiting the die of an extrusion head.” 

J.A. 946. The district court determined, however, that the 

’921 and ’812 patents do not use “parison” in the ordinary 

sense. The district court found convincing Plastic Omnium’s argument that, while traditionally a parison is a 

“plastic test-tube like structure” “formed outside of the 
PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC. 7

extrusion head/die,” the parison described in the ’921 and 

’812 patents cannot be formed entirely outside of the extrusion head/die because the parison described in the patents 

is split or cut into two sheets of plastic as it is being extruded. J.A. 947. Thus, the district court’s construction did 

nothing to undermine the plain and ordinary meaning of 

the term “parison” insofar as the term refers to something 

that is formed by exiting the die of an extrusion head. Instead, the construction clarified that the term in the context of the patent could refer to a tubular preform structure 

that exists only momentarily after exiting the die at the 

bottom of the extrusion head, but before being split in two 

sheets by the blades placed at the exit of the die. The majority is therefore wrong to discount the Donghee’s documentation supporting Plastic Omnium’s argument because 

both the patent and a person of ordinary skill in the art use 

the term to refer to a structure that is created when molten 

plastic exits a die at the end of an extrusion head. 

Moreover, the fact that the patentee acted as his own 

lexicographer does nothing to undermine Plastic Omnium’s 

double die argument. In defining “extruded parison,” the 

patentee never limited the mechanisms by which the 

claimed parison can be cut. Further, in construing “extruded parison,” the court put no restrictions on where or 

how the parison must be cut, only that it occur “as [the parison] exits the die or at sometime thereafter.” J.A. 946. 

Nothing prevents the claimed parison, under the district 

court’s construction and the patent’s definition, from being 

cut within a structure such as Donghee’s flat die tool, so 

long as it is created by a die before it is cut. Under Plastic 

Omnium’s double die argument, a parison would be created 

by the die at the bottom of Donghee’s coextrusion die tool, 

satisfying that requirement. 

III

The district court took its eye off the ball. It knew for 

sure that the big question in this case is whether Donghee’s 
8 PLASTIC OMNIUM ADVANCED v. DONGHEE AMERICA, INC.

accused structure includes a separate die that creates an 

extruded parison which is cut after it emerges from the extrusion die. And we have to assume it knew about the evidence from Plastic Omnium’s expert (Dr. Osswald), whose 

credibility and credentials are unchallenged. Dr. Osswald 

pointed to the spiral mandrel at the bottom of Donghee’s 

extrusion head as the die that creates the extruded parison 

which is cut in Donghee’s flat tie tool. Donghee may disagree with Dr. Osswald, but by any count, the district court 

left unresolved a material factual dispute over the structure of Donghee’s accused device, a material factual dispute the majority is unwilling to confront. The district 

court deprived Plastic Omnium of its day in court, and the 

majority perpetuates that error. 

A material factual dispute prevents summary judgment. See Dorel Juvenile Grp., Inc. v. Graco Children's 

Prod., Inc., 429 F.3d 1043, 1047 (Fed. Cir. 2005) (vacating 

grant of summary judgment of noninfringement because a 

material factual dispute existed over how the accused product functioned); Hilgraeve Corp. v. McAfee Assocs., Inc., 224 

F.3d 1349, 1353 (Fed. Cir. 2000) (“These differences in the 

experts’ descriptions of [the allegedly infringing process’s]

operation raise a genuine issue of material fact.”). This 

court should vacate the district court’s summary judgment 

of noninfringement, and remand the case for resolution of 

the dispositive material factual dispute.