PTAB

IPR2025-01116

Albany Intl Corp v. Voith Patent GmbH

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Clothing for a Machine for Producing a Fibrous Material Web
  • Brief Description: The ’566 patent describes structural features of paper machine clothing (PMC), which is a belt-like fabric used in papermaking machines. The invention purports to solve disadvantages in the seam area of the PMC by claiming specific dimensionless ratios for seam "loop density" (between 64% and 90%) and the ratio of seam loop diameter to machine-direction thread diameter ("LD/MDYD" ratio, between 2.7 and 3.6).

3. Grounds for Unpatentability

Ground 1: Obviousness over Sudre and Adanur - Claims 1, 3, and 10-13 are obvious over Sudre in view of Adanur.

  • Prior Art Relied Upon: Sudre (WO 89/12717) and Adanur (a 2017 industry standard textbook, Paper Machine Clothing).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Sudre taught the conventional method for making a flat-woven PMC endless by forming a two-ply laminate structure with seam loops. While Sudre provided the general structure, it did not specify fabric parameters. Adanur, described as an industry-standard textbook, disclosed exemplary cross-sections of "actual finished press fabrics." Petitioner's expert measured images from Adanur to determine key parameters, arguing that the combination of Sudre's structure with Adanur's real-world parameters rendered the claimed invention obvious. Specifically, the measurements from Adanur yielded an average machine-direction (MD) thread diameter of 0.32 mm, a thread density of 13.3 threads/cm, and a seam loop diameter of 0.96 mm. These values were used to calculate a loop density of approximately 85% and an LD/MDYD ratio of 3.0, both falling within the ranges of claim 1.
    • Motivation to Combine: A POSITA seeking to produce a PMC according to Sudre’s general method would combine it with the specific, conventional parameters found in an industry-standard source like Adanur to meet the "particular requirements of its intended end use." Adanur provided valuable and hard-to-find information on the parameters of functional, finished press fabrics.
    • Expectation of Success: A POSITA would expect success because both references pertain to seamed, flat-woven PMCs, and Sudre imposed no special requirements that would suggest deviating from conventional parameters like those shown in Adanur.

Ground 2: Obviousness over Sudre, Lee, and Penven - Claims 1, 3, and 10-13 are obvious over Sudre in view of Lee and Penven.

  • Prior Art Relied Upon: Sudre (WO 89/12717), Lee (WO 2014/172594), and Penven (Patent 4,806,208).
  • Core Argument for this Ground:
    • Prior Art Mapping: As in Ground 1, Petitioner relied on Sudre for the base endless fabric structure. Lee was cited for teaching specific ranges for MD thread diameter (0.3mm to 0.6mm) and yarn density (5.9 to 15.7 yarns/cm), including an example with a 0.4mm diameter and 9.45 yarns/cm density. Penven was cited for teaching a conventional seam loop diameter ("internal void diameter") of about 50 mils (1.27mm). Petitioner argued that combining these known parameters rendered the claims obvious. Using Lee's specific example, the resulting loop density was calculated to be 75.6%. Combining Penven's loop diameter (1.27mm) with Lee's example thread diameter (0.4mm) yielded an LD/MDYD ratio of 3.175. Both calculated values fall within the ranges claimed in the ’566 patent.
    • Motivation to Combine: A POSITA would look to sources like Lee and Penven to supply the specific parameters not disclosed in Sudre's general method. Lee provided suitable ranges for thread size and density for seamed press felts, and Penven provided a typical dimension for seam loops compatible with standard pintles.
    • Expectation of Success: A POSITA would expect success because all three references pertain to conventional seamed PMCs, and their teachings were compatible. Lee's parameters were conventional, and Penven's loop size was described as typical for such fabrics.

Ground 3: Obviousness over Sudre and Rydin - Claims 1, 3, and 12-13 are obvious over Sudre in view of Rydin.

  • Prior Art Relied Upon: Sudre (WO 89/12717) and Rydin (a 1992 Swedish technical article).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner again used Sudre for the foundational PMC structure. Rydin, an article describing a "new generation seam felt" from the early 1990s, provided actual photographs of a finished PMC and its underlying seam. Petitioner argued these photographs demonstrated that PMCs possessing the claimed features existed long before the patent's priority date. Although Rydin's figures lacked a metric scale, Petitioner's expert performed a dimensionless analysis based on pixel measurements. This analysis yielded a loop density of approximately 78% and an LD/MDYD ratio of approximately 3.2, both within the claimed ranges.
    • Motivation to Combine: A POSITA would look to a source like Rydin, which described desirable improvements for a well-known manufacturer's PMC, to identify parameters for implementing Sudre's general method. A POSITA would seek to apply the disclosed relative loop sizing and thread spacing to achieve a fabric with improved homogeneity in the seam zone.
    • Expectation of Success: A POSITA would expect success because the dimensionless relationships (ratios) derived from Rydin are independent of the absolute scale and could be applied to a fabric of any specific dimension. The underlying principle—that loop diameter relative to thread diameter correlates to strain—is a fundamental concept.

  • Additional Grounds: Petitioner asserted numerous additional obviousness challenges by combining the primary references of Grounds 1-3 with secondary references Shipley (for weave patterns), Straub (for welded joints), Lidar (for elastomeric nonwoven fibers), and Yook (for flow-impeding elements) to meet limitations of dependent claims 2, 4-9, 14, and 15.

4. Key Technical Contentions (Beyond Claim Construction)

  • The petition's central technical contention was that the claimed numerical ranges for "loop density" and the "LD/MDYD ratio" were not inventive but were inherent, dimensionless properties of conventional PMCs well-known in the art.
  • Petitioner heavily relied on expert analysis of images from prior art publications (Adanur and Rydin). It was contended that a POSITA could and would derive the necessary parameters by direct measurement from such images, even performing dimensionless pixel-based calculations where a metric scale was absent, to arrive at the claimed ratios.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-15 of the ’566 patent as unpatentable.