The opinion of the court was delivered by: Judge Rebecca R. Pallmeyer
Judge Rebecca R. Pallmeyer
MEMORANDUM OPINION AND ORDER
Plaintiffs Itex, Inc. ("Itex") and MF&H Textiles, Inc. ("MF&H") are manufacturers of flame-retardant fabrics. In 1995, Plaintiffs obtained a patent for their cotton blend fabrics entitled, "Long Wear Life Flame-Retardant Cotton Blend Fabrics." U.S. Patent No. 5,468,545 ("the '545 Patent"). Defendants are twelve corporations that manufacture, sell and/or rent flame-retardant fabrics. In two separate lawsuits, Plaintiffs charge Defendants with infringing the '545 Patent by manufacturing or selling certain flame-retardant cotton blend fabrics that infringe at least one of the patent's claims. The parties presented competing interpretations for several terms in Claim 1 of the '545 patent, and on July 10, 2010, Judge Andersen issued an opinion setting forth the court's construction of those terms. Itex, Inc. v. Westex, Inc., No. 05 CV 6110, 2010 WL 2927474 (N.D. Ill. July 20, 2010). Defendants have moved for partial reconsideration, requesting that this court modify or reconsider Judge Andersen's construction of a specific term found in Claim 1: "cotton fabrics." For the reasons set forth below, Defendants' motion is granted.
In October 2008, Plaintiffs filed their Second Amended Complaint alleging that Defendants VF Imagewear, Inc. ("VF"), Mount Vernon Mills, Inc. ("Mount Vernon") and Carhartt, Inc. (Carhartt), infringed the '545 Patent by making or selling flame-retardant cotton blend fabrics. In an earlier lawsuit, Plaintiffs have also charged a second set of Defendants-Westex, Inc. ("Westex"), King America Finishing, Inc. ("King"), Western Piece Dyers & Finishers, Inc. ("Western"), Workrite Uniform Company, Inc. ("Workrite"), VF Imagewear, Inc. ("VF"), Cintas ("Cintas"), Unifirst ("Unifirst"), G & K Services ("G&K"), Aramark ("Aramark"), Greenwood Mills, Inc. ("Greenwood")- with infringing the '545 Patent.*fn1 Both cases were originally filed before Judge Andersen, who conducted a Markman hearing in December 2009 on several disputed terms within Claim 1 of the '545 Patent. See Markman v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed. Cir. 1995) (en banc), aff'd, 517 U.S. 370 (1996). By Executive Order dated October 29, 2010 , these cases were reassigned to this court, and the court conducted a further Markman hearing in February 2011 on the single disputed term now at issue: "cotton fabrics." This opinion will therefore presume the reader's familiarity with the general background of the '545 patent as described in Judge Andersen's July 10, 2010 Memorandum Opinion and Order, see Itex, Inc. v. Westex, Inc., No. 05 CV 6110, 2010 WL 2927474 (N.D. Ill. July 20, 2010), but the facts relevant to the pending motion are briefly summarized below.
As noted above, Plaintiffs patented certain chemically-treated cotton blend fabrics. Generally speaking, woven cotton blend fabrics*fn2 are produced by interlacing two distinct sets of yarns-in this case: cotton and thermoplastic fibers-to form an elongated fabric. (Markman Hearing Tr. at 7.) Adding thermoplastic or synthetic fibers, such a nylon or polyester, to cotton fabric makes the fabric more durable because thermoplastic fibers are more resistant to abrasion and natural wear and tear. (Id. at 11.) Blending cotton fabric with synthetic fibers generates flammability concerns, however. Pure cotton fabric is naturally flammable, but it can be rendered flame-resistant when it is treated with a chemical compound, tetrakis phosphonium (hereinafter, "THP/urea compound"), and an ignited fabric so treated will self-extinguish once the flame source is removed.*fn3 (Id. at 11.) Thermoplastic fibers are also highly flammable but, unlike cotton fibers, cannot be treated with the conventional THP/urea compound. In the past, companies in the textile industry attempted to address the problem by either (1) treating cotton blend fabric as if it were 100% cotton, using the typical level of the THP/urea compound, or (2) increasing the level of chemicals in the cotton fibers only, in the hope that the high level of flame-retardant chemicals overall would compensate for the thermoplastic fibers. Neither of these approaches was fully satisfactory. The former solution was not adequate because the flame-retardant chemicals washed off of the thermoplastic fibers, and the latter solution produced a fabric that was stiff and uncomfortable. ('545 Patent, col.1 Is.30-31.) Plaintiffs' invention sought to solve this problem by producing a cotton blend fabric in which only the cotton fibers are flame-retardant and the thermoplastic fibers are limited to no greater than thirty percent of the overall fabric. Presumably, the flame-retardant chemicals will continue to wash off of the non-cotton fibers, but overall, the resulting softer fabric will remain flame-retardant because it contains a sufficient level of "phosphorous-containing polymer to retard the burning of both the cotton and the non-flame-retardant thermoplastic fibers."*fn4 (Pls.' Claim Construction at 6.)
The parties asked Judge Andersen to construe several disputed terms in Claim 1 of the '545 Patent. In Claim 1, the patent claims:
1 - Wash resistant durable fabrics, including woven fabrics comprising:
a) 50 to 95% cotton fibers; 5-30% non-flame-retardant thermoplastic fibers in which warp yarns for woven fabrics are comprised of 50 to 95% cotton and 5 to 30% non-flame-retardant thermoplastic fibers;
b) said fibers being uniformly treated with a durable flame retardant of a prepolymer of urea and tetrakis (hydroxymethyl) phosphonium salt which has been applied, ammoniated and oxidized in a manner such that
c) after exposure to five washes and twenty-four hours emersion in boiling water
i) the cotton fabrics burn less than 15cm (6") at cut edges and
ii) retain at least 2.0% and no more than 3.0% phosphorous by weight of fabric.
('545 Patent, col.8 Is.29-44.) The only term at issue for reconsideration is the term "cotton fabrics" in Part (c)(i). In their claim construction brief, Defendants argued that term "cotton fabrics" was ambiguous because the term was not identified in any preceding claim language, and a person of ordinary skill in the art could not reasonably ascertain the meaning of the term. (Defs.' Claim Construction at 39-40.) Plaintiffs initially claimed that the term "cotton fabric" was synonymous with the preceding term, "woven fabric"; in a later submission, they urged that using the term "cotton fabrics" was an "obvious typographical error" which "clearly should have been 'woven fabrics.'" (Pls.' Claim Construction at 12; Pls.' Rebuttal at 40.) Judge Andersen agreed that Plaintiffs must have meant "woven fabrics" when they instead used the expression "cotton fabrics" in Part (c)(i). He found that the terms were not synonymous-"as 'cotton fabrics' are different from 'woven fabrics' that contain both cotton and ...