ITC Institutes Investigation of Extrusion-Coated Magnet Wire on Essex Solutions' Patent Complaint.

The investigation

The Commission instituted Certain Extrusion-Coated Magnet Wire, Inv. No. 337-TA-1527, on October 29, 2026 (91 FR 69275-76, Nov. 3, 2026). The complaint was filed on September 29, 2026 under section 337 of the Tariff Act of 1930 and supplemented on October 13, 2026, on behalf of Essex Solutions Inc. and Essex Solutions USA LLC, both of Atlanta, Georgia. The complainants ask for a limited exclusion order and cease and desist orders. The notice defines the scope as "extrusion-coated magnet wire having an outer layer formed from an extruded thermoplastic resin."

The notice names two respondents: Wellascent Electronic (Ganzhou) Co., Ltd. of Ganzhou, China, and Wellascent Technologies USA LLC of Grand Prairie, Texas. The Office of Unfair Import Investigations will not participate as a party, and the Chief Administrative Law Judge will designate the presiding administrative law judge.

The patents and instituted claims

The Commission instituted on claims 1 and 3 of U.S. Patent 8,847,075; claims 1-4 of U.S. Patent 9,224,523; and claims 1-5 of U.S. Patent 10,210,966.

U.S. Patent 8,847,075, titled Insulated Wire, issued September 30, 2014. Claim 1 covers an insulated wire with a conductor, a baked enamel layer containing at least a polyamide-imide on the outer periphery of the conductor directly or through an insulated layer, and at least one extrusion-coated resin layer on the outer side of the baked enamel layer, where the baked enamel layer has at least one functional group selected from a carboxyl group, an ester group, an ether group, and a hydroxyl group on its outer surface and adheres to the extrusion-coated resin layer. Claim 3 covers claim 1 where the conductor has a rectangular cross-section.

U.S. Patent 9,224,523, titled Inverter Surge-Resistant Insulated Wire, issued December 29, 2015. Claim 1 covers an inverter surge-resistant insulated wire with at least one baked enamel layer around a conductor and a single extrusion-coated resin layer outside it, the resin being selected from polyether ether ketone, a thermoplastic polyimide, a polyamide having an aromatic ring, a polyester having an aromatic ring, and polyketone. The claim sets limits on the thickness of each layer and of both together, a minimum tensile elastic modulus of 100 MPa to 400 MPa for the extrusion-coated layer over the range of 25 to 250°C, ranges for the dielectric constant of the combined insulation layer at 25°C and 250°C, and a ratio between the dielectric constants of the two layers at 250°C. Claim 2 covers claim 1 where the extrusion-coated layer is formed of polyether ether ketone, claim 3 where the conductor has a rectangular cross-section, and claim 4 where the baked enamel layer is 40 μm or less.

U.S. Patent 10,210,966, titled Insulated Wire and Coil, issued February 19, 2019. Claim 1 covers an insulated wire with a rectangular conductor and a thermoplastic resin layer on it, where the adhesion strength between the resin layer and the conductor on one pair of opposed sides differs from the adhesion strength on the other pair, by a difference of 5 gf/mm to 100 gf/mm. Claim 2 narrows the difference to 10 gf/mm to 50 gf/mm. Claim 3 covers claim 1 where the resin is at least one of polyether ether ketone, polyether ketone ketone, polyketone, polyphenylene sulfide, and thermoplastic polyimide, claim 4 where the conductor is copper, oxygen-free copper, or a copper alloy, and claim 5 a coil formed by winding the wire of claim 1.

The parallel district court suit

On September 25, 2026, Essex Solutions Inc. and Essex Solutions USA LLC sued the same two Wellascent entities in the Northern District of Texas, Dallas Division, Essex Solutions Inc. v. Wellascent Electronic (Ganzhou) Co., Ltd., No. 3:26-cv-03373. The docket shows the case assigned to Judge Karen Gren Scholer. The complaint asserts the '075, '523, and '966 patents and U.S. Patent 10,566,109, titled Insulated Wire, Coil and Electrical or Electronic Equipment (issued February 18, 2020), and demands a jury. It alleges direct and induced infringement by wire products with a conductor and an outer thermoplastic resin layer such as polyether ether ketone, and alleges, based on public importation records, that Wellascent Technologies was the importer of record for a shipment of about 11.9 metric tons of that wire from Wellascent Ganzhou that entered at Long Beach, California on July 21, 2026. It also alleges that a related Essex company filed suit in China on Chinese counterparts of the '523 and '966 patents, and alleges, on information and belief, that Wellascent knew of the patents before suit because of that litigation, which it says began on August 15, 2025. The prayer asks for a judgment of infringement and willfulness, an injunction, damages including treble damages, and attorneys' fees under 35 U.S.C. 285. The docket shows summons issued on September 29, 2026.

What to watch next

Under 19 CFR 201.16(e) and 210.13(a), the notice says the Commission will consider responses to the complaint and the notice of investigation if received within 20 days after service. The notice also asks the presiding judge to consider what information is needed on the domestic industry allegations under subparagraphs (A), (B), and (C) of 19 U.S.C. 1337(a)(3), including the extent to which they rely on expenditures made by third parties and on expenditures made outside the United States. Watch for the designation of the presiding judge, the respondents' responses, and a procedural schedule.