PTAB

IPR2025-00664

HS Hyosung Advanced Materials Corp v. Kolon Industries Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method of Manufacturing Hybrid Tire Cord
  • Brief Description: The ’663 patent discloses a method for manufacturing a hybrid tire cord from aramid and nylon yarns. The method involves twisting both yarns in the same direction and plying them together in a single, continuous process using one twister, while applying differential tension such that the aramid yarn is 1.005 to 1.025 times longer than the nylon yarn when untwisted.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 are obvious over Tamura, Rowan, and Fritsch, optionally in view of Buchanan

  • Prior Art Relied Upon: Tamura (Japanese Patent No. 2009-68549), Rowan (Patent 6,886,320), Fritsch (Application # 2003/0159768), and Buchanan (European Patent App. No. 0405887A1).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the asserted prior art collectively teaches every limitation of the challenged claims. Tamura taught the basic hybrid tire cord comprising twisted aramid and nylon yarns. Rowan taught a "one-machine process" using a single twister (a direct cable unit) to simultaneously and continuously perform the primary twisting and plying steps, addressing the limitations of multi-step, multi-machine processes. Buchanan was cited as an alternative to further support the teaching of simultaneous twisting of yarns in a single apparatus. Fritsch taught creating an "unbalanced configuration" in a hybrid cord by modulating tension on individual plies, which results in one yarn being longer than the other when untwisted. Fritsch's disclosure of a "Coring level" was argued to explicitly teach the claimed length differential of 1.005 to 1.025 times (0.5% to 2.5%). For claims 2 and 3, Rowan was asserted to teach the subsequent treatment steps of dipping the plied yarn in an adhesive, drying it, and thermally treating it in a continuous process with controlled tension.
    • Motivation to Combine: A POSITA would combine Tamura and Rowan to improve manufacturing efficiency and reduce costs, as Rowan explicitly taught using a single apparatus to replace the "laborious and expensive" multi-step process for making cords from materials like nylon and aramid. A POSITA would further incorporate Fritsch’s teachings to improve the cord's physical properties, such as tensile strength, by creating a known, beneficial length differential between the higher-modulus aramid yarn and the lower-modulus nylon yarn. Applying Rowan's tensioning of less than 0.4 g/d to Tamura's cord was presented as a straightforward application of a known treatment parameter.
    • Expectation of Success: Petitioner contended a POSITA would have a reasonable expectation of success because the references are all in the analogous art of cord manufacturing. Rowan's single-twister apparatus was designed to handle nylon and aramid, and Fritsch’s tension-modulating techniques were applicable to the types of tensioning devices (brakes and rolls) described in Rowan. The combination was argued to be a predictable integration of known technologies to achieve expected benefits.

Ground 2: Claims 1-2 are obvious over Fritsch alone

  • Prior Art Relied Upon: Fritsch (Application # 2003/0159768).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Fritsch, by itself, rendered the claims obvious. Fritsch disclosed a method for making a hybrid cabled cord for use in tires from different materials, including aramid and nylon. It taught using a "direct cabler" machine that performs all twisting steps—individually twisting flat yarns and then plying them together—in a single, continuous process. This machine was argued to meet the "one twister" limitation for simultaneous and continuous operation. Critically, Fritsch’s core teaching was the creation of an "unbalanced configuration" by applying differential tension to achieve a specific "Coring level," or length difference. Fritsch's disclosed examples and preferred ranges (e.g., a non-zero value up to 25%) were argued to encompass the claimed range of 1.005 to 1.025 times longer for the higher-modulus yarn (aramid). For claim 2, Fritsch was also said to teach a "dip/dry/stretch/dip/relax process" for treating the cord with an adhesive agent like Resorcinol Formaldehyde Latex.
    • Motivation to Combine (within a single reference): The argument centered on a POSITA being motivated to apply different teachings within Fritsch to one another. For instance, a POSITA would be motivated to apply Fritsch’s disclosed 0.9% Coring level—which showed a good balance of breaking strength and elongation—to the aramid-nylon hybrid cord embodiment also taught by Fritsch to predictably improve its physical properties.
    • Expectation of Success: Success would be expected as the argument involved applying principles and embodiments taught within the same reference. Fritsch provided detailed instructions for its treatment process and taught that the tension-altering method was achievable on the same direct cabling device used for the aramid-nylon embodiment.

4. Key Claim Construction Positions

  • Petitioner submitted that no express constructions were required to find the claims unpatentable. However, for clarity, it adopted the patent's own specification-based descriptions for key terms:
    • "primarily twisted yarn": a single yarn made by twisting one filament yarn in one direction.
    • "plied yarn": a yarn made by twisting two or more primarily twisted yarns together.
    • "tire cord": includes both a raw, untreated "plied yarn" and a "dip cord" treated with an adhesive agent.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under Fintiv would be inappropriate. The petition asserted that the parallel district court litigation was in a very early stage, with the trial date set for February 3, 2026, well after the statutory deadline for a Final Written Decision. It was argued that minimal investment had occurred in the district court case and that the merits of the IPR petition were compelling, presenting prior art and arguments not previously considered by the USPTO.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-3 of the ’663 patent as unpatentable.