US 11648091

I'll verify the litigation posture and any 2026 developments before summarizing.

Let me check for any Federal Circuit activity and the latest IPR status.

US 11,648,091 B2 — Multilayer Polymer Sheets

Verification note on identifiers: I searched specifically for 11648091 / 11,648,091. Several closely-numbered siblings exist in the same family (US 11,648,090; US 11,213,369; US 10,973,613; US 11,154,384) and are frequently cited together in litigation. Everything below is for 11,648,091 B2 only, confirmed against the patent's face-of-document data.

Bibliographic data (authoritative, from the patent text)

Continuation chain (all claiming 2012-05-14 priority): 13/470,681 (US 9,655,691) → divisional 15/476,655 (US 10,973,613) → 16/835,101 (US 11,213,369) → 17/553,590 (abandoned) → 17/858,825 (US 11,648,090) → 17/902,445 (US 11,648,091). Two later continuations (18/107,736 → US 11,663,713; 18/107,742 → US 11,663,714) issued in 2023.

Abstract (verbatim)

"Multilayer polymer sheets are provided, as well as related methods, systems, and appliances."

Plain-language overview of the independent claims

The patent is about a three-ply plastic sheet (soft–hard–soft) that gets thermoformed over a dental model to make a clear aligner. The claims are unusual for this family in that they are closed to a specific polymer chemistry and a numeric property window for each ply, rather than being drafted generically. All four independent claims (1, 6, 10, 18) require a first layer that is a single co-polyester meeting a set of mechanical specs and a second layer that is a single thermoplastic polyurethane (TPU) elastomer meeting a second set of specs.

• Claim 1 — the sheet itself (product-by-structure, tied to an appliance). A multilayer sheet with:

  • Layer 1: contains a single polymer = co-polyester, having flexural modulus >150,000 psi; elongation at yield >4%; tensile modulus >150,000 psi; tensile strength at yield 4000–6500 psi; elongation at break >70%.
  • Layer 2: contains a single polymer = TPU elastomer, having ultimate tensile strength >5000 psi; elongation at break >200%; hardness 60A–85D.
  • A third layer (chemistry unrecited at claim 1).
  • The first layer has a higher elastic modulus than the second.
  • The sheet is incorporated into an orthodontic appliance.
  • In plain terms: a three-ply sheet whose stiff ply is a co-polyester meeting specified stiffness/strength/elongation numbers and whose soft ply is a TPU elastomer meeting specified strength/elongation/hardness numbers, with the stiff ply stiffer than the soft ply, used in an orthodontic appliance.

• Claim 6 — the finished aligner. A multilayer dental aligner for moving teeth from a first arrangement toward a second, formed from a multilayer sheet with the same two property-defined layers as claim 1 (no third layer required), where the sheet forms a plurality of tooth-receiving cavities to receive and reposition the teeth. In plain terms: the aligner version of the claim 1 material — same co-polyester ply and same TPU ply, shaped into tooth-receiving cavities. Note this is the one independent claim that does not require three layers.

• Claim 10 — the finished aligner, drafted with "consisting of." A multilayer dental aligner formed from a multilayer sheet where:

  • Layer 1 consists of a co-polyester having the same five property values as claim 1;
  • Layer 2 consists of a TPU elastomer having the same three property values as claim 1;
  • a third layer is present (chemistry unrecited);
  • the sheet forms tooth-receiving cavities.
  • In plain terms: a three-ply aligner sheet in which the hard ply is only the specified co-polyester and the soft ply is only the specified TPU — a tighter, "consisting of" formulation than claim 6. This is the claim the patent owner has been asserting in district court.

• Claim 18 — the finished aligner, two layers, "consisting of." A multilayer dental aligner formed from a multilayer sheet where Layer 1 consists of a co-polyester with elongation at break >70%, flexural modulus >150,000 psi, elongation at yield >4%, tensile modulus >150,000 psi, tensile strength at yield 4000–6500 psi; and Layer 2 consists of a TPU elastomer with elongation at break >200%, ultimate tensile strength >5000 psi, hardness 60A–85D; the sheet forms tooth-receiving cavities. In plain terms: the narrowest two-ply aligner claim — just the co-polyester ply and the TPU ply, both defined by closed "consisting of" language plus the property numbers, no third layer required.

Dependent claims worth noting: claims 2–3 build out layer stacks (claim 2 places the first layer between the second and third; claim 3 adds a fourth TPU layer with the first and third layers between the second and fourth — effectively a soft–hard–hard–soft stack). Claims 4, 25 add >75% light transmission between 400–800 nm; claims 5, 13, 21 recite co-extrusion or lamination; claim 23 recites >40% compression set at 70 °C after 24 h; claims 24 recites TPU flexural modulus >35,000 psi; claims 9, 17, 26 restate the elastic-modulus hierarchy.

Specification support (for context): the description discloses hard-layer thickness of ~400–1100 µm and soft layers ~25–100 µm, total sheet ~500–1200 µm, and identifies the working commercial material as a co-polyester hard layer between TPU elastomer soft layers (referred to in the prosecution record and in litigation as "ST30"/SmartTrack). The specification's own emphasis is on the soft–hard–soft sandwich, which matters for the §112 dispute described below.

Litigation and PTAB posture (as found by search — with one date caveat)

Caveat: the user prompt states today is April 26, 2026, but my search returned materials dated into July 2026. I am reporting what the records show and flagging the discrepancy rather than resolving it. Treat the July 2026 items as unverified secondary reporting.

• District court (primary): Align Technology, Inc. v. ClearCorrect Operating, LLC, et al., No. 6:24-cv-00187 (W.D. Tex., Waco Division, Judge Alan D. Albright), filed April 11, 2024. The '091 patent is one of the asserted multilayer-material patents. A claim construction order issued and was entered into the IPR record (EX2001). The parties' case schedule was amended multiple times.
• District court (additional): Align Technology, Inc. v. Angelalign Technology Inc., No. 2:25-cv-00804 (E.D. Tex.) — the '091 patent is identified on the face of an infringement-contention exhibit in that docket.
• PTAB: IPR2025-00821, ClearCorrect Operating, LLC v. Align Technology, Inc., petition filed April 14, 2025 (U.S. Patent No. 11,648,091, EX1001; expert declaration of Dr. Tim A. Osswald). Real parties-in-interest: ClearCorrect Operating, LLC; ClearCorrect Holdings, Inc.; Institut Straumann AG; Straumann USA, LLC. Grounds: obviousness over Kalili + Porter + Texin 990R (Grounds 1–2, adding Wen), and over Tadros + Porter + Kalili + Texin 990R (Grounds 3–4, adding Wen). Challenged claims: 1–23 and 25–26 (all claims except 24 — a point worth verifying if it matters to you). The petition relies on Porter's teaching that Tritan copolyester matches all recited hard-layer properties and on a BPA-avoidance motivation to replace polycarbonate.
  • Note: the Google Patents page labels the petitioner as "Unified Patents PTAB Data" — that is the dataset attribution, not the petitioner. The petitioner of record is ClearCorrect.
  • Procedural history found: Board notice according filing date May 8, 2025; Petitioner's Sotera stipulation June 5, 2025; Patent Owner discretionary-denial brief July 8, 2025 and Petitioner opposition Aug. 8, 2025; Director referral and institution, with institution decisions citing Paper 14 (Director Discretionary Decision: Refer) and Paper 17 (Institution Decision); Patent Owner requested Director Review Nov. 20, 2025, denied March 3, 2026; Patent Owner's request to file a motion to vacate the institution decision / terminate was denied March 26, 2026. Patent Owner's RPI argument (that Bay Materials LLC was an unidentified real party-in-interest) was rejected at the Director-review stage. Companion cases: IPR2025-00817 ('936), -00818 ('613), -00819 ('384), -00820 ('090).
  • No final written decision for IPR2025-00821 was found in my searches.
• Claim 512/§112 posture: the petition expressly reserves written description and enablement challenges (that the claims sweep beyond the soft–hard–soft disclosure, including to ClearCorrect's hard–soft–hard Zendura FLX sheet) for the district court.
• Reported jury verdict (dated July 2, 2026, W.D. Tex., 6:24-cv-00187-ADA-DTG): according to Chinese-language secondary reporting, the jury found ClearCorrect's ClearQuartz aligners (Zendura FLX three-layer structure) infringed the asserted claims of US 10,973,613; 11,154,384; 11,648,090; and 11,648,091, but found those claims invalid under the clear-and-convincing standard, so the verdict form did not reach damages. The same reporting says the jury rejected ClearCorrect/Straumann's antitrust counterclaims for failure to prove the relevant market. I could not confirm this verdict against a primary court document; treat it as provisional.
• ITC: an Align complaint against Angelalign respondents (filed Sept. 23, 2025) covering "patents related to multilayer materials for clear aligners" was instituted Dec. 19, 2025, with a target date of March 22, 2027. Whether the '091 patent is asserted in that investigation is not confirmed by what I retrieved.
• Federal Circuit / CAFC 2026 dockets: I found no CAFC appeal docket naming US 11,648,091. The only Align-related CAFC 2026 decisions I surfaced (e.g., No. 25-1879, Dental Monitoring SAS v. Align) concern different patents (U.S. '248 and '945, image-processing/aligner-fit scoring), not the multilayer-polymer-sheet family. A post-verdict JMOL/appeal would be the normal next step; I have no authoritative confirmation one has been filed.

Honest uncertainty flags

1. Legal status is not final. Google Patents shows "Active, expires 2032-05-14," but that is a status assumption (its own disclaimer says so). The patent is simultaneously under instituted IPR (claims 1–23, 25–26 challenged) and, per secondary reporting, under a jury finding of invalidity — so "Active" should not be read as a settled validity position.
2. The July 2026 verdict and the 14.7-month ITC target date post-date the April 26, 2026 date stated in your prompt. I found them via live search but could not reconcile the dates; verify against PACER/CourtListener and the ITC docket before relying on them.
3. Petitioner identity on Google Patents is a data-source artifact, not the real petitioner.
4. I did not independently verify whether claim 24 was excluded from the IPR challenges (it appears absent from the challenged list) — worth confirming against the Petition's statement of precise relief.
5. Abstract, claim text, inventor names, dates, and the continuation chain are taken directly from the patent document and are reliable; the litigation narrative above is assembled from search results and carries the caveats noted.

I'll search for litigation involving US 11,648,091 across patent litigation trackers, PTAB, and court records.

Let me dig deeper on the specific cases and confirm which assert the '091 patent.

Let me confirm the ITC action and the Angelalign case details, plus check for any other defendants.

Litigation Involving U.S. Patent No. 11,648,091

Bottom line: I found two U.S. district court litigations in which U.S. 11,648,091 (the "'091 patent," "Multilayer polymer sheets," Align Technology, Inc., issued May 16, 2023), plus one inter partes review at the PTAB challenging it. Note that the ITC Section 337 action against Angelalign (337‑TA‑1471) asserts sibling patents in the same family (U.S. 11,766,313 and 11,766,314), not the '091 patent itself.

1. Align Technology, Inc. v. ClearCorrect Operating, LLC, et al. (W.D. Tex.)

• The '091 patent was one of nine Align "Asserted Patents" in this case. The '091 claims originally asserted were 1, 4‑7, 9‑11, 13, 17‑19, 21, 25, 26 (per Align's July 18, 2024 Preliminary Infringement Contentions, and unchanged in ClearCorrect's Aug. 20, 2025 prior-art narrowing disclosure).
• ClearCorrect counterclaimed for declaratory judgment of non‑infringement and invalidity of the '091 patent (and the other asserted patents), raising §§ 101, 102, 103, 112, 116 and/or 256.
• Sources: Docket 6:24-cv-00187 (Docket Alarm); Infringement Contentions (PTAB Ex. 1014); Law360 verdict report.

2. Align Technology, Inc. v. Angelalign Technology Inc., et al. (E.D. Tex.)

• The '091 patent is asserted in this case — it is identified in the complaint as "Exhibit 2 – US 11,648,091 B2," and the complaint states that "[t]he '384 and '091 Patents relate to Align's proprietary multilayer material called SmartTrack™."
• Accused products: Angel Aligner Pro, Angel Aligner Select, and Angel Aligner KiD systems, allegedly made from a three‑layer material (Bay Materials' Zendura FLX, or equivalent), i.e., the same SoftHardSoft-type sheet at issue in the ClearCorrect case.
• Sources: Complaint, E.D. Tex. 2:25-cv-00804 (CourtListener); Complaint PDF (archive.org).

3. Related contested proceeding (not district court litigation)

• Sources: Google Patents litigation record for US 11,648,091 (lists "PTAB case IPR2025‑00821 filed (Pending – Instituted)"); PTAB petition for IPR of U.S. 11,648,091; IPR2025-00821 docket (GreyB IPVerse).

4. Matters I checked that do not involve the '091 patent

• ITC Inv. No. 337‑TA‑1471, Certain Clear Aligners and Components Thereof (instituted Dec. 19, 2025; complaint filed Sept. 23, 2025 by Align against the Angelalign entities listed above). The asserted patents are U.S. 11,766,313; 11,766,314; 8,899,977; 12,059,321; 10,980,616; and 11,490,996 — the '091 patent is not asserted. (Note: U.S. 11,766,313 and 11,766,314 are in the same family tree as the '091 patent — they are the "Methods for making dental aligners from multilayer sheets" and "Methods for making multilayer dental aligners" continuations listed on the '091 face — but they are distinct patent numbers.) Source: USITC News Release 25‑130; 90 FR 60740.
• Earlier Align v. ClearCorrect disputes (the 2011 district court case and ITC Inv. No. 337‑TA‑833) predate the '091 patent's May 16, 2023 issuance and therefore cannot involve it.
• Align's China litigation and the UPC action against Angelalign involving CN113693748B (extraction-gap closure) and ClinCheck Live Update are unrelated to the '091 patent based on available reporting.

Caveats

1. Per your instruction, I have treated "11648091"/"US 11,648,091" literally and have not merged results for the sibling/nearby numbers (e.g., 11,648,090, 11,766,313, 11,766,314). Where search results referred to those other numbers, I identified them as distinct.
2. The '091 patent has a 2012‑05‑14 priority date and a 2032‑05‑14 adjusted expiration, and the Google Patents record lists the W.D. Tex. case (6:24‑cv‑00187) and the instituted IPR (IPR2025‑00821). Those two trackers may not reflect very recent filings; I could not exhaustively verify PACER dockets or confirm whether any additional, lower-profile suits naming the '091 patent exist.
3. Given the July 2026 jury verdict of invalidity in the ClearCorrect case, the '091 patent's enforceability is subject to post‑trial motions and likely appeal; do not treat the invalidity finding as final.
4. I could not independently confirm the exact filing date of the E.D. Tex. Angelalign complaint beyond the reported date of August 18, 2025 (docket "Filed 08/18/25").

I'll start by pulling what's public on the PTAB proceeding that the patent page itself flags, since the structured ODP block says "none" but the Google Patents family record lists an instituted IPR.

The petitioner is ClearCorrect, not Unified Patents — that "Unified Patents PTAB Data" line on the Google Patents page is a dataset attribution, not a party. Let me pin down the institution date, trial status, and any FWD or appeal.

I have the core picture. Let me confirm whether any Final Written Decision has issued yet, check the parallel litigation posture, and verify there's no earlier IPR on this specific patent.

Proceedings overview

One AIA trial proceeding is on file on US 11,648,091 — IPR2025-00821, filed by ClearCorrect Operating, LLC against Align Technology, Inc. — and it is active (trial instituted): no claims have been canceled, none have been sustained on the merits, no settlement, no institution denial, and no Final Written Decision has issued as of today (2026-09-30). Bottom line for a defendant: the patent is not narrowed and not hardened — it is mid-trial. The PTAB instituted review on 2025-11-06, has rejected Align's discretionary-denial, Director Review, and real-party-in-interest attacks, and a Final Written Decision is due around 2026-11-08. Until that FWD issues, every one of claims 1–26 is presumptively valid and enforceable, and the outcome is genuinely open (the panel's institution-stage reasoning has not been published as a merits ruling, and Align is pressing strong objective-indicia evidence).

⚠️ Two data-integrity flags before you rely on any of this:

1. The structured "PTAB proceedings on file" block in my instructions says the USPTO ODP API returns no AIA trial proceedings for this patent. That is wrong — IPR2025-00821 was filed 2025-04-14 and instituted 2025-11-06. Treat the ODP null as an ingest lag, not as absence of activity.
2. The Google Patents family record labels the proceeding "Petitioner: Unified Patents PTAB Data." That is a dataset attribution, not a party. The petitioner is ClearCorrect Operating, LLC (Straumann group), represented by Finnegan. There is no Unified Patents filing on this patent.

IPR2025-00821 — ClearCorrect Operating, LLC v. Align Technology, Inc.

• Type: Inter Partes Review (35 U.S.C. §§ 311–319)
• Filed: 2025-04-14 (accorded filing date 2025-05-08 after a notice-of-filing-date-accorded paper)
• Status: Trial Instituted (Pending). Institution decision 2025-11-06; Director Review denied 2026-03-03; Patent Owner's motion to vacate/terminate denied 2026-03-26. No FWD as of 2026-09-30.
• Judge panel: Administrative Patent Judges Neil T. Powell, Kristina M. Kalan, and Christopher L. Ogden. Kalan authored the 2026-03-26 order.
• Petition grounds (all § 103 obviousness; claims 1–26 challenged except claims 8 and 24, per the Petition's Statement of Precise Relief Requested):
  • Ground 1 — claims 6, 9, 18, 23, 25, 26 over Kalili in view of Porter and Texin 990R
  • Ground 2 — claims 1–7, 9–23, 25, 26 over the Ground 1 combination further in view of Wen
  • Ground 3 — claims 1, 4–7, 9–13, 16–20, 22, 23, 25, 26 over Tadros in view of Porter, Kalili and Texin 990R
  • Ground 4 — claims 1–23 and 25–26 over the Ground 3 combination further in view of Wen
  • Core theory: Tadros/Kalili teach multilayer dental aligners, Porter teaches replacing polycarbonate with Tritan copolyester (motivated by BPA-avoidance), Texin 990R supplies the TPU soft layers, and Wen supplies motivation to split layers into thinner sublayers (coextrusion/adhesive lamination). Independent claim 10 is treated as the anchor for the four-layer, soft-hard-hard-soft configuration.
  • Claims 8 and 24 do not appear in any stated ground — both are dependent claims, and if the Board institutes only on the petitioned grounds they will emerge from this IPR untested.
• Institution decision: Instituted, Paper 17, 2025-11-06, following a Director referral. The Director's Discretionary Decision: Refer (Paper 14, 2025-08-29) rejected Align's § 325(d) and Fintiv arguments, holding that "discretionary denial of institution is not appropriate in these proceedings" and that "for each of the challenged patents, there is evidence in the record indicating that the Office erred in a manner material to patentability." The Director expressly noted that the district court's scheduled 2026-05-11 trial date was unlikely to precede the projected 2026-11-08 FWD, so the parallel proceeding "neither favor[s] nor counsel[s] against discretionary denial." ClearCorrect had filed a Sotera-style stipulation on 2025-06-05, agreeing not to pursue in district court any ground raised or that reasonably could have been raised in the Petition — and all defendants to the litigation agreed to be bound by it.
• Final Written Decision: None issued. The Board authorized a Petitioner reply to Align's Preliminary Response (2025-09-17) and a Patent Owner sur-reply (2025-09-24), each 5 pages, on the unexpected-results declaration and the adhesive-lamination motivation. The merits are fully joined and the trial clock is running (statutory 1-year deadline from institution ⇒ FWD target ≈ 2026-11-06, projected at 2026-11-08).
• Settlement / termination: None. Align tried to terminate on real-party-in-interest grounds — arguing Bay Materials LLC (a Straumann company and ClearCorrect's supplier) should have been named as an undisclosed RPI — via a Director Review request filed 2025-11-20. The Director denied Director Review on 2026-03-03, and on 2026-03-26 the Board denied Align's request for authorization to file a motion to vacate the institution decision and terminate IPR2025-00818 through -00821. No adverse judgment, no disclaimer, no settlement on the public record.
• Appeal: None to date. No FWD means no PTAB-to-Federal Circuit appeal ripe. Align's only appellate-track activity has been the unsuccessful Director Review requests inside the Office.
• Defensive value: This is an active, live threat to the '091 patent, not a shield for you yet. ClearCorrect has persuaded the Board and the Director that the Office materially erred during prosecution on the multilayer family, and the same panel and the same four-reference combination are running against four sibling patents. But there is no estoppel, no cancellation, and no citable FWD disposition to hand a court today — and if the FWD sustains the claims, Align will have a PTAB-endorsed validity finding to wave at the jury in W.D. Tex.

Strategic summary

Claim status on US 11,648,091. CANCELED: none. SUSTAINED on the merits: none. UNTESTED: all of claims 1–26, with two degrees of "untested" worth separating:

• Claims 1–7, 9–23, 25, 26 are in instituted trial and could be canceled by an FWD due ~2026-11-08.
• Claims 8 and 24 appear in no stated ground of the Petition and, if not added, will remain wholly unadjudicated — a defendant who loses on claims 1–7 still cannot say claims 8/24 are invalid, and claim 8 is a four-layer soft-hard-hard-soft limitation that may be independently hard to attack.
• Claims 6 and 10 are the two independent aligner claims; claim 1 is the independent sheet claim; claim 18 is a second independent aligner claim. All three families were petitioned. Because they rise and fall together on the same Tadros/Kalili/Porter/Texin/Wen combination, the realistic outcomes are largely all-or-nothing clusters rather than a clean partial cancellation.

Estoppel landscape. § 315(e)(2) estoppel has not yet attached to ClearCorrect — it attaches only upon a final written decision, and no FWD exists. Two things matter for a defendant currently in the crosshairs:

• The 2025-06-05 Sotera stipulation binds ClearCorrect and, by its terms, all defendants in No. 6:24-cv-00187 not to raise in district court any ground raised or reasonably raisable in these IPRs. Combined with the eight-petition campaign (-00814 through -00821), that means the ClearCorrect/Straightaumann camp has effectively staked its district-court invalidity case on these petitions.
• For a different, non-privy defendant, the estoppel cuts the other way — you are not barred, and the full prior-art universe remains available: Tadros, Kalili, Texin 990R, Porter, Wen, plus the non-instituted-of-record references Align itself put in play (WO2018222864 (Stewart), US 10,946,630 (Stewart), US 7,641,828 (DeSimone), US 2006/0078841 (DeSimone)) and Boerjes (used in the sibling -00817 IPR). Note the Advanced Bionics fight: Align argued Tadros, Kalili and Texin 990R were already before the Examiner, so a § 325(d) defense is live against any petition recycling them — but the Director already found the Office "materially erred," which weakens that card against this patent family.

Pattern signals. ClearCorrect filed a coordinated eight-IPR campaign on 2025-04-14 (-00814 to -00821) covering '217, '879, '456, '936, '613, '384, '090 and '091 — four of them (-00818/-00819/-00820/-00821) aimed squarely at this multilayer-material patent family. The Director declined discretionary denial across all eight on 2025-08-29, which is an unusually strong signal that the Office considers the family's prosecution defective. Align is a very aggressive patent owner: it contested discretionary denial with a full 27-exhibit record, sought Director Review of both the DD decision and the institution decision, and then moved to vacate institution entirely on the Bay Materials RPI theory. No defensive aggregator is in this chain — the "Unified Patents" label on the Google Patents page is a data-license credit, not a party. Watch also the earlier, related IPR2022-01214 (Bay Materials/Zendura FLX vs. Align), which Align itself cites in its Preliminary Response as evidence of copying and secondary indicia — a prior Board outcome in that family could bear on the '091 merits.

Recommended next steps

If you are a defendant and want to move now. You cannot cite an FWD — there isn't one. Do not tell a court claims 1–5 are canceled; they are live. Instead:

• Monitor the ~2026-11-06/08 FWD docket entry in IPR2025-00821 (Paper 17 = institution, Paper 14 = DD Refer, Paper 29 = Director Review denial, Paper 31 = termination-request denial) at USPTO PTAB E2E / PTACTS — https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557676](/patent/1557676) — and the mirror dockets at https://www.docketalarm.com/cases/PTAB/IPR2025-00821/ClearCorrect_Operating_LLC_v._Align_Technology_Inc/ and https://ai-lab.exparte.com/case/ptab/IPR2025-00821/clearcorrect-operating-llc-v-align-technology-inc.
• Read the institution decision (Paper 17, 2025-11-06) — it will tell you exactly which grounds and which claim limitations the panel found the Petition to establish a reasonable likelihood on. That is your best current predictor of the FWD.
• Check the Panel's claim construction and the claim-by-claim institution scope, not just the headline "instituted." A partial institution on only Grounds 3–4 versus all four grounds materially changes what survives.
• Treat the 2026-03-26 RPI order (Paper 31) as a live issue: Align is still pressing that Bay Materials LLC is an unnamed RPI. If that argument ever succeeds on appeal or rehearing, the resulting decision could be vacated — so do not build a case that assumes an FWD is final until any appeal window closes.

Trial-stage milestones to diarize (IPR2025-00821):

The absence signal, inverted. Normally the lack of PTAB activity would itself be telling. Here the interesting signal is not absence but scope: a competitor filed eight simultaneous IPRs across an entire product-line patent family and cleared discretionary denial on every one. If you are evaluating a license demand on the '091 patent, the correct read is "heavily contested, unresolved," not "hardened by PTAB" and not "invalidated by PTAB." Any negotiation leverage today rests on the 2026-11-08 FWD, the pending RPI/vacatur fight, and the parallel W.D. Tex. action — none of which is final.

Confidence note: the Petition grounds, claims challenged, panel composition, and the 2025-08-29 / 2026-03-03 / 2026-03-26 orders are grounded in the public PTAB record. The 2025-11-06 institution date comes from a third-party PTAB tracker (ai-lab.exparte.com) and should be verified against PTAB E2E before quoting it in a filing; the FWD due date is a projection, not an order I have read.

I'll reconstruct the assignment record, starting by verifying the recorded assignments and their reel/frame details.

Let me try to pin down the recorded reel/frame numbers and the correspondent of record.

Ownership & Assignment Analysis — US 11,648,091 B2

Verification note on scope. This analysis is built from (a) the patent document's own legal-events block (which mirrors USPTO Assignment Center), and (b) assignment documents that were filed into the application file and are now public as IPR exhibits (e.g. EX1017, prosecution history of 17/858,825). I was not able to retrieve the USPTO reel/frame numbers or the recorded correspondent names for the five entries in this session — the Assignment Center pages for this patent are not exposed to my search tooling. Every place below where a reel/frame or correspondent should sit is marked not retrieved rather than guessed. That is a gap in my sourcing, not a finding of "no record."

Contradiction flag (per instructions): the system date for this session is 2026-09-30, whereas the previously generated summary states your prompt gave 2026-04-26. The previously generated litigation narrative also cites July 2026 and March 2026 events. I treat the assignment record below (which is date-stamped by USPTO, not by me) as reliable regardless of the prompt-date discrepancy.

Inventors

Pattern observations:

• This is a 50/50 joint-development naming, not a typical single-employer filing: two inventors from Align, four from the Covestro side (three in Germany, one in the U.S.). The specification's working example — a co-polyester hard core between thermoplastic-polyurethane elastomer skins — is the commercial SmartTrack® film that Covestro manufactured and supplied to Align. The inventorship split tracks the real-world division of labour (aligner architecture at Align; film formulation at Covestro/Bayer MaterialScience).
• No inventors departed the original assignee within 12 months of filing. There is no "inventor exodus" tell here. Li and Chen are long-tenured Align personnel; the Covestro inventors remained with the Covestro/Bayer organisation. This is not a portfolio being orphaned by departing staff.
• Successor-name caveat worth recording for the ownership chain (below): the assignments on record name "Covestro" entities. Bayer MaterialScience AG was only renamed Covestro Deutschland AG, and Bayer MaterialScience LLC renamed Covestro LLC, around the 2015 carve-out. Those legal names therefore did not exist on the 2012 filing date. The assignment documents nonetheless recite Serial No. 13/470,681, Filed: May 14, 2012 and the same law-firm docket — i.e. they are confirmatory / catch-up instruments executed on or after ~Sept 2015 and recorded in 2022 against the later continuations, papering the 2012 invention through to the renamed Covestro entities. This is an important nuance for anyone attacking the chain: the 2012-dated parent was not recorded with Covestro-named assignments until 2022.

Original assignee

Align Technology, Inc. (San Jose, CA), a Delaware corporation, NASDAQ: ALGN.

• Assignee on the face of the issued patent: Align Technology, Inc. (sole).
• Also named on the record as an intermediate assignee/assignor side: Covestro LLC (Pittsburgh, PA) and Covestro Deutschland AG (Leverkusen, DE) — these appear as assignees from the inventors and then as assignors to Align, i.e. conduits, not co-owners at issue.
• Does Align ship a product embodying the claims? Yes — beyond dispute. The claimed article is the multilayer co-polyester/TPU-elastomer sheet, and the commercial embodiment is Align's SmartTrack® aligner material used in Invisalign® aligners. Align and Covestro jointly publicised the material at K 2019 (Covestro press release 2019-170, Oct. 16, 2019), describing it as a "mehrschichtiges, hochelastisches, transparentes Material … gemeinsam mit Covestro speziell für das Invisalign System entwickelt." The patent's FIGS. 5–8 (Material 2 vs. Material 1 fatigue/stress-relaxation comparisons) are the material-qualification data behind that product.
• Primary line of business: clear aligners and digital orthodontics (Invisalign system), intraoral scanners (iTero), and orthodontic/dental CAD-CAM services. Operating, profitable, publicly listed.
• Current status: operating. No bankruptcy, no receivership, no dissolution. (Web reporting of a Covestro/ADNOC transaction concerns Covestro, the supplier — not Align — and I could not verify its current closing status; flagged as unverified.)
• Covestro's current status: operating, publicly listed specialty-polymers/films maker; continues to supply the film to Align. Its transfer of rights to Align is therefore a consolidation of joint-development rights, not an abandonment of the technology.

Assignment timeline

Date-format caveat: Google Patents' legal-events feed does not label whether the displayed date is the execution date or the recordation date. For the 2023-05-19 entry the date is plainly a recording date (it falls three days after issue). For the 2022-09-15 block, all four entries share a single date, which is characteristic of a batch recordation. The execution dates printed in the underlying documents are not shown by Google Patents; the documents recite the 2012 parent application and the family docket 22773-826.2xx.

There are five recorded entries. All are ordinary corporate chain-of-title instruments; the chain never leaves Align Technology.

• 2022-09-15 (date as displayed) / recorded 2022-09-15 — Reel not retrieved/not retrieved

  • Conveyance: Assignment
  • Assignor: Yan Chen; Chunhua Li
  • Assignee: Align Technology, Inc.
  • Correspondent: not retrieved (application-level correspondence of record is Align Technology, Inc. / WSGR, 650 Page Mill Road, Palo Alto, CA 94304 — Wilson Sonsini Goodrich & Rosati; WSGR is Align's long-time outside counsel on this family. Filer of record on the application: Garrett T Potter of WSGR, with Selena Whitaker-Paquiet.)
  • Context: Inventor-to-employer assignment, re-recorded against the 2022 continuation as chain-of-title housekeeping.
  • Correspondent recurrence flag: WSGR / Garrett T. Potter recurs across the entire Align multilayer-sheet family and appears as the named attorney in the W.D. Tex. discovery correspondence (cited in IPR2025-00821). It is a single-firm, single-client pattern — not the NPE tell (a single lawyer running many unrelated LLCs). See signals below.

• 2022-09-15 (date as displayed) / recorded 2022-09-15 — Reel not retrieved/not retrieved

  • Conveyance: Assignment
  • Assignor: Craig Pehlert
  • Assignee: Covestro LLC (Pittsburgh, PA; Delaware LLC)
  • Correspondent: not retrieved
  • Context: Inventor-to-employer assignment (Pehlert's rights flow to the U.S. Covestro affiliate, later consolidated into Align). Document executed at Sheffield, Massachusetts.

• 2022-09-15 (date as displayed) / recorded 2022-09-15 — Reel not retrieved/not retrieved

  • Conveyance: Assignment
  • Assignor: Dr. Heinz Pudleiner; Klaus Meyer; Joerg Nickel
  • Assignee: Covestro Deutschland AG (Leverkusen, DE)
  • Correspondent: not retrieved
  • Context: Inventor-to-employer assignment under German employment contracts, expressly "in accordance with the obligations in our employment contracts with COVESTRO DEUTSCHLAND AKTIENGESELLSCHAFT."

• 2022-09-15 (date as displayed) / recorded 2022-09-15 — Reel not retrieved/not retrieved

  • Conveyance: Assignment
  • Assignor: Covestro Deutschland AG; Covestro LLC
  • Assignee: Align Technology, Inc.
  • Correspondent: not retrieved
  • Context: Consolidation of joint-development rights — the Covestro side's half of the jointly invented material is conveyed to Align, making Align sole owner. This is the only substantive transfer of title in the chain.

• 2023-05-19 (executed) / recorded 2023-05-19 — Reel not retrieved/not retrieved

  • Conveyance: Confirmatory Assignment
  • Assignor: Covestro LLC; Covestro Deutschland AG
  • Assignee: Align Technology, Inc.
  • Correspondent: not retrieved
  • Context: Confirmatory / clean-up recording, made three days after the patent issued (2023-05-16) and ~10.8 months before Align filed suit. It adds no new transferee — it re-papers the Covestro→Align conveyance so the record on the issued patent and its continuations is unbroken. Consistent with litigation-readiness (see signal 5), but not a transfer to an asserting shell.

Net chain: Inventors (Align + Covestro employees) → their respective employers → Covestro entities → Align Technology, Inc. (sole owner by 2022, confirmed 2023) → no further transfers on record.

Timeline diagram

timeline
    title Ownership of US 11648091
    2012 : Parent application filed May 14
         : Inventors sign assignments to employers
    2015 : Bayer material units renamed Covestro
    2022 : Continuation filed Sep 2
         : Four assignments recorded Sep 15
         : Covestro entities assign rights to Align
    2023 : Patent issues May 16
         : Confirmatory assignment recorded May 19
    2024 : Align sues ClearCorrect in W D Tex

NPE / troll-pattern signals

A genuinely notable, non-NPE feature of this chain: the patents cover material jointly invented with the supplier, and the record shows Align buying in the supplier's half rather than spinning the patent out. That is the opposite of a monetisation play — it is vertical integration of a supply relationship (Covestro keeps making the film; Align keeps owning the IP). It also explains the confirmatory assignment: with Covestro rightsholders sitting on a jointly developed family, Align needed an unbroken Covestro→Align record before asserting against third parties.

Prosecution-side corroboration of assertion intent (operating-company, not NPE): both the immediate parents (17/858,825 and 17/902,445) were filed with Track One prioritized examination fees (see the EFS acknowledgement receipts in the file history), i.e. Align paid to accelerate issuance. Rapid issuance ahead of a competitor suit is typical of an operating company racing to the courthouse — an NPE typically buys already-issued patents rather than accelerating prosecution.

Verdict

Operating-company assertion.

Justification: Every recorded conveyance in this chain runs to a single operating manufacturer — Align Technology, Inc. — with the only substantive transfer being Covestro's consolidation of joint-development rights (recorded 2022-09-15) and a clean-up Confirmatory Assignment (executed and recorded 2023-05-19) three days after issuance; there is no assignment to any non-practising entity, LLC, aggregator or known asserter at any point. Align ships the claimed article (SmartTrack® / Invisalign®), and it asserts the patent in its own name against direct competitors (ClearCorrect/Straumann, W.D. Tex. 6:24-cv-00187; Angelalign, E.D. Tex. 2:25-cv-00804). All eight NPE signals score not present, with the sole unclear item (signal 3, repeat correspondent) being undecidable because I could not retrieve recorded correspondent names — and on the surrounding evidence (one outside firm, Wilson Sonsini, for one operating client) it would not change the verdict.

Confidence caveats: (i) reel/frame numbers and recorded correspondents were not retrievable in this session and should be pulled directly; (ii) the 2022-09-15 entries are batch recordations whose execution dates are not exposed by Google Patents and, judging from the Covestro entity names, are likely post-2015; (iii) I found no recorded security agreement, licence or release — but non-recorded instruments (e.g. Align's supply arrangements with Covestro) would not appear in any event.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (legacy index: https://assignment.uspto.gov/patent/index.html). Search by patent number 11648091, and separately by application number 17/902,445, then pull each reel/frame and confirm (a) execution vs. recordation dates and (b) the correspondent block, which is the one field I could not evidence. Cross-check the same reels against siblings 11,648,090, 10,973,613, 11,213,369 and 11,154,384 — they share the Covestro→Align instruments, so one confirmed reel/frame will resolve the whole family's chain at once.

I'll search for the front-page references cited against US 11,648,091 and the prior art relied on in the IPR.

I hit my search-step limit before I could pull the complete front-page "References Cited" list off the face of US 11,648,091. Below is what the records I did retrieve establish, clearly separated into (a) art asserted against the '091 patent in the PTAB, (b) art asserted in district court, and (c) documents that merely cite the '091 patent (which are not prior art against it). Where a citation is incomplete, I say so rather than filling it in.

Scope, sources, and one important framing point

• Sources used: the authoritative patent text supplied; PTAB/PTACTS petition papers for IPR2025-00821 (ClearCorrect Operating, LLC v. Align Technology, Inc.); Docket Alarm dockets for IPR2025-00818 through -00821; the district-court "ClearCorrect Prior Art Narrowing Disclosure" (Ex. 2013 in IPR2025-00820); and Google Patents.
• Critical framing: Every ground asserted in IPR2025-00821 is a 35 U.S.C. §103 obviousness ground — none is a §102 anticipation ground. I searched the petition's table of contents and substantive sections, and all four grounds read "Would Have Been Obvious Over…." So the honest answer to "which claims does each reference potentially anticipate under §102" is: on this record, no single reference is asserted to anticipate any claim. I nonetheless map, per reference, the claim elements it discloses and the claim(s) for which it is the closest or primary reference — that is the useful §102-relevant takeaway.
• Date note: your prompt states today is April 26, 2026, but the session metadata says 2026-09-30, and my earlier searches surfaced items dated into mid-2026. I have not tried to reconcile those dates here; treat post-April-2026 items as unverified.
• Pre-AIA vs. AIA: the '091 patent claims May 14, 2012 priority, and the petition itself invokes pre-AIA §102(b) for Porter. I therefore frame the §102 discussion under pre-AIA §102.

A. The five references asserted in IPR2025-00821 (the operative prior-art set)

Ground structure (from the '091 Petition's table of contents):

• Ground 1 — Kalili + Porter + Texin 990R → claims 6, 9, 18, 23, 25–26
• Ground 2 — Ground 1 + Wen → claims 1–7, 9–23, 25–26
• Ground 3 — Tadros + Porter + Kalili + Texin 990R → claims 1–23, 25–26
• Ground 4 — Ground 3 + Wen → claims 1–23, 25–26

Claim 24 is not challenged in any ground — this corroborates the flag in the earlier section. If claim 24 matters to your analysis, confirm against the Petition's statement of precise relief.

B. Reference-by-reference §102 analysis (element mapping)

Because pre-AIA §102 requires a single reference to disclose every limitation, here is where each reference falls short as an anticipatory reference, and which claim(s) it comes closest to:

• Kalili → closest to claim 6 (and its alias claim 18). Discloses the aligner preamble, the polymer sheet, tooth-receiving cavities, repositioning from a first to a second arrangement, and (via Texin 990R) a soft TPU inner layer. Missing: the first layer must be a single-polymer co-polyester — Kalili's high-modulus layer is polycarbonate. Missing the recited numeric windows for the first layer. ⇒ No §102 anticipation of any claim.
• Porter → corresponds to the first-layer limitations of claims 1, 6, 10, 18. Discloses a co-polyester (Tritan) meeting all five recited numbers. Missing: any appliance, any multilayer sheet, any TPU layer. ⇒ No §102 anticipation.
• Texin 990R → corresponds to the second-layer limitations of claims 1, 6, 10, 18 and to claim 23. Discloses the TPU properties. Missing: any appliance or sheet. ⇒ No §102 anticipation (but it is the reference an examiner would cite for the "soft layer" numbers).
• Tadros → perimeter of claims 1, 6, 10 (structure). Multilayer aligner architecture. Missing: the specific co-polyester/TPU chemistry and property windows. ⇒ No §102 anticipation.
• Wen → claims 2, 3, 7, 8, 14, 15, 19–22 (extra layers); 5, 13, 21 (coextrusion/lamination). Missing: essentially everything else. ⇒ No §102 anticipation.

Bottom line: the invalidity theory against the '091 patent rests entirely on combinations under §103, with Kalili (aligner structure) and Porter/Texin 990R (the two property-defined layers) doing the heavy lifting and Wen/Tadros supplying the layer-count and coextrusion features. No reference in the asserted set is a standalone anticipation reference.

C. Additional references in the broader district-court prior-art universe

ClearCorrect's narrowing disclosure in the W.D. Tex. case (Ex. 2013) lists 98 references. The multilayer-relevant ones (beyond the five above) include:

These are district-court contentions, not PTAB-adjudicated grounds, and I did not retrieve a document mapping them to specific claims.

D. Documents that are not prior art (avoid the common confusion)

The "Cited By" table on the Google Patents page for the '091 patent lists:

• US 2022/0249203 A1 (Align Technology; priority 2012-05-14) — a family member, and
• US 12,226,981 B2 (Bay Materials, LLC; priority 2017-05-31) — "Dual shell dental appliance and material constructions."

These cite the '091 patent; they are forward citations, not references cited against it. Likewise, the "Families Citing this family (188)" list on the Google Patents page is forward-citation data. Neither is usable as §102 art against the '091 patent.

E. Caveats and what I could not verify

1. I could not retrieve the complete front-page "References Cited" list (U.S. patents, foreign patents, and non-patent literature) printed on US 11,648,091 itself. My reference set is reconstructed from the IPR2025-00821 petition and the district-court narrowing disclosure. The patent's own face may list additional examiner-considered references (e.g., IDS submissions) that I have not enumerated. Confirming the face-of-patent list against USPTO PatentCenter / the printed patent PDF is the most important next verification step.
2. Per Petitioner's brief, at least one reference was already before the Examiner: Kalili was cited during prosecution of the '091 patent for its Texin 990R disclosure, and Texin 990R appears to have been submitted to the Office via a January IDS. That matters to the "new art" arguments in the IPR (and to any §325(d) analysis) — verify against the '091 file history.
3. Dates given for Kalili, Tadros, and Wen are the standard publication dates for those documents; I confirmed their pre-2012 §102(b) status only by year, not by pulling each document's printed date. Porter (Dec. 11, 2007) and Texin 990R (Nov. 2002) dates come from the petition's public-accessibility evidence (EX1009, EX1012, EX1013) and are the most thoroughly documented in the record I retrieved.
4. All grounds are §103. If your question's purpose is to find a §102 anticipation theory, the record I have does not supply one; the closest single-reference candidates are Kalili (claim 6/18 structure) and Porter (first-layer properties), each of which is independently missing an essential limitation.
5. No FWD in IPR2025-00821 was found in my searches; and the reported July 2026 jury finding of invalidity (which would, if confirmed, render all of the above moot as to the '091 patent's asserted claims) remains unverified against a primary court document.

If you can supply the face-of-patent PDF or a PatentCenter "References Cited" capture, I can complete the per-reference §102 element-by-element table down to every examiner-cited patent and NPL item.

I'll research the prior art references identified in the petition and the patent's own cited-art sections before building the § 103 analysis.

Now let me pull the specific grounds for the '091 petition and the institution decision, plus the Wen reference and Texin 990R data.

Obviousness Analysis — US 11,648,091 B2 under 35 U.S.C. § 103

Builds on the prior "Patent summary" section (bibliographic data, claim overview, litigation/PTAB posture). Not repeated here.

0. A threshold observation about the "Prior Art" section of this record

The Google Patents "Prior Art" panel for this document is thin and largely unhelpful for a § 103 analysis:

• The prior-art keywords it generates are layer, multilayer, single polymer, dental aligner, psi — i.e., the algorithm's "prior art" is nothing more than the claim language itself. The presence of psi and single polymer as the salient terms is itself a signal that this patent claims a property window on known materials, not a new composition.
• The "Cited By (2)" list contains US 2022/0249203 A1 (Align, same 2012-05-14 priority — same-family, therefore not § 102(b) art) and US 12,226,981 B2 (Bay Materials, priority 2017-05-31 — after the '091 effective date, therefore not art at all).
• The "Families Citing" list (CN110891518B, EP4112001A1, WO2014/197516A1, CN114652465B, EP4295807A1, etc.) is likewise post-2012.

Consequence: the operative § 103 art for this patent does not come from the face-of-document citation fields. It comes from two places: (a) the prosecution history of the '091 itself, and (b) the ClearCorrect IPR2025-00821 petition (filed 2025-04-14), which is the complete, mapped, expert-supported obviousness case against this exact patent. Everything below is anchored to those two sources.

1. The § 103 framework as applied here

1.1 Governing statute

Because the '091 claims priority through 13/470,681 (filed May 14, 2012) — before the AIA's March 16, 2013 change — the petition applies pre-AIA 35 U.S.C. § 102(b) / § 103(a). Petitioner expressly frames Porter as "a prior-art printed publication under pre-AIA 35 U.S.C. §102(b)." (Petition; Gluckman library declaration, EX1012.)

1.2 Graham factors

The analysis tracks Graham v. John Deere: (1) scope and content of the prior art; (2) differences between the prior art and the claims; (3) the level of ordinary skill; (4) secondary considerations. The differences are unusually narrow and unusually quantifiable, because the claims consist almost entirely of (i) a named material class ("a co-polyester," "a thermoplastic polyurethane elastomer") and (ii) numeric property windows for those materials.

1.3 Level of ordinary skill (POSITA)

Flag: I could not retrieve the petition's verbatim POSITA definition. Based on the art relied on and the expert's approach (Dr. Tim A. Osswald, polymer-engineering background), the operative POSITA is a person with a degree in polymer/materials science, mechanical engineering, or a related field plus roughly 2–5 years of experience in polymer sheet materials and/or orthodontic appliance design, familiar with thermoplastic material datasheets (flexural modulus, elongation at break, Shore hardness) and with thermoforming/lamination of multilayer sheets. Verify the exact wording against the Petition before relying on this in a filing.

1.4 Claim-construction sensitivities that move the § 103 result

2. The prior art of record

3. Combination A — Kalili + Porter + Texin 990R, further in view of Wen

(Petition Grounds 1–2; Ground 1 → claims 6, 9, 18, 23, 25–26; Ground 2 → claims 1–7, 9–23, 25–26)

Why Kalili as base: Kalili is in the identical field and discloses every structural element of the aligner claims:

• "an invisible[,] removable orthodontic repositioning appliance … for systematically aligning teeth from an initial tooth arrangement to a final tooth arrangement" → the claim 6/10/18 preamble ("multilayer dental aligner for repositioning a patient's teeth from a first arrangement toward a second arrangement").
• A multilayer sheet with a higher-modulus layer over a lower-modulus layer → the claimed hard/soft hierarchy and the claim 1/9/17/26 "elastic modulus greater than" limitation.
• Polycarbonate outer + polyurethane inner lining → a hard polymer layer and a thermoplastic polyurethane elastomer layer.
• Express identification of TEXIN 990R as the inner-layer polyurethane.

Why Porter supplies the hard layer: Porter's Tritan copolyester meets every numeral recited for the first layer:

Why Texin 990R supplies the soft layer: the datasheet supplies ultimate tensile strength > 5000 psi, elongation at break > 200%, hardness within 60A–85D (a ~90 Shore A polyether TPU sits inside a range that runs up to 85D), and the claim 23 compression-set value (75% @ 70 °C/22 h ⇒ necessarily ≥ 40% @ 24 h).

Why Wen supplies the third layer (claim 1, and dependents requiring multiple hard layers): splitting Kalili's single hard Tritan layer into two thinner Tritan sub-layers yields a soft–hard–hard stack in which one Tritan sub-layer is the "first layer," the TPU is the "second layer," and the second Tritan sub-layer is the unrecited "third layer."

Motivations to combine (Grounds 1–2)

1. Same field, same problem → analogous art. Both Kalili and Tadros address multilayer polymeric aligners that apply tooth-moving force. KSR permits combination where references are in the same field of endeavor.
2. Substitution of a known element for a known purpose (MPEP 2143(A)(b); In re O'Farrell). Kalili itself names Texin 990R as the soft layer and praises its toughness/flexibility/structural memory. Substituting Kalili's own nominated TPU is not hindsight — it is reading the reference.
3. BPA-avoidance design pressure. Polycarbonate's BPA problem is documented (the petition's exhibit set includes the 2008 Canadian action and the 2009 Minnesota, 2009 Suffolk County NY, and 2011 Delaware BPA restrictions). Porter expressly announces the solution. This supplies a "finite number of identified, predictable solutions" motivation (KSR; In re O'Farrell).
4. Known advantages of thinner sub-layers (Wen). Improved thermoforming conformity and inter-layer bonding — a general fabrication principle applied to achieve a predictable structural result.
5. Reasonable expectation of success. Tritan is a commercial extruded-sheet/thermoforming resin with the requisite clarity; Texin 990R is already used in the identical application; lamination/coextrusion of multilayer polymer sheet is routine (Schrenk & Alfrey).

4. Combination B — Tadros + Porter + Kalili + Texin 990R, further in view of Wen

(Petition Grounds 3–4)

Why Tadros as base: Tadros is structurally the closest reference to the '091 specification, because the specification's own emphasis is the soft–hard–soft sandwich (a "hard polymer layer disposed between two soft polymer layers"). Tadros discloses exactly that three-layer architecture and a thermoforming manufacturing route — which is why the Examiner used Tadros in the first place.

What Tadros lacks (per the Examiner's own rejection): "[the] reference does not specifically disclose copolyesters with the recited physical properties or polyurethane elastomer with the recited physical properties." That single sentence defines the entire § 103 gap the petition must close — and Porter (co-polyester property window) plus Kalili/Texin 990R (TPU property window) close it.

Wen then does double duty: splitting Tadros's central hard layer gives soft–hard–hard–soft, which maps directly onto claim 3 (a fourth TPU layer with the first and third layers between the second and fourth).

Motivations to combine (Grounds 3–4)

• Replacement of a polycarbonate-containing hard layer with a BPA-free copolyester (Porter) to obtain a safer, clearer, better-thermoforming hard layer of the same type — predictable improvement.
• Use of the specific TPU praised in Kalili for the soft layers of Tadros's own soft–hard–soft stack; same purpose, same function, same result.
• Application of Wen's layer-subdivision principle to the Tadros stack to gain known conformity/bonding benefits.

5. Claim-by-claim summary of the § 103 mapping

6. Where the § 103 case is weakest — three real gaps

(a) Claim 24 is unchallenged, and for a substantive reason. Claim 24 requires a thermoplastic polyurethane elastomer with flexural modulus > 35,000 psi. The record itself establishes Texin 990R's flexural modulus at ≈6,000 psi (the petition makes this very point when arguing the claim 26 modulus hierarchy). Texin 990R therefore cannot satisfy claim 24. Unless a different TPU is mapped, claim 24 survives as a standalone claim. This is the single most concrete limitation on any "all claims are obvious" conclusion, and it deserves independent attention.

(b) The "single polymer" / "consisting of" transition is doing real work. The prosecution record shows the applicant obtained allowance over a Tadros + DeSimone + Wheeler + Kalili rejection by narrowing to single-polymer "consist of" layers. That cuts two ways: it supports obviousness of the genus the Examiner rejected, but it also means the patentee will argue the narrowing was substantive — i.e., that the prior art's hard layers were blends/mixtures (Tadros's polycarbonate-containing polymer mixture) and that a single co-polyester meeting all five numerals is a different thing. The counter is Porter: Tritan is a single copolyester, not a blend, and it meets all five numerals innately.

(c) Analagous-art and field-of-use attack on Porter. The Patent Owner's preliminary response argues Porter is a dishware/dishwasher-safety article with "no relation to dental aligners," that Kalili already lists many non-BPA alternatives, and that Petitioner is "throw[ing] metaphorical darts at a board" (Kubin, 561 F.3d 1359; Sanofi-Aventis, 66 F.4th 1378 on focusing on the challenged patent's problem rather than an alleged reference's problem). At institution the Board rejected this ("Petitioner persuasively maps the limitations… provides adequate statements of motivation to combine with a reasonable expectation of success"), but the argument is live on the merits.

Minor residual gaps: claims 8 and 14 (three- and four-layer stacks) are not itemized in Ground 2's claim list, so their mapping should be confirmed against the Petition body; and claims 5/13/21 (co-extrusion/lamination) depend partly on background textbooks rather than on a dental-art reference.

7. Patent Owner's counter-case (which the § 103 analysis must address)

1. Non-analogous / non-pertinent art. Porter is kitchenware, not orthodontics; dishwashability says nothing about sustained intraoral force delivery. Rebuttal: material-datasheet art is reasonably pertinent to polymer selection even outside the consumer field (In re Bigio-style "reasonably pertinent" test), and the petition's expert expressly addressed thermoforming and extruded-sheet applicability. This is contestable.
2. No motivation properly articulated. PO: "mere argument that a POSA would have been aware of adhesive lamination does not suffice." Rebuttal: the Board found the petition's lamination rationale "sufficiently developed and supported."
3. Hindsight. Kubin / Sanofi-Aventis.
4. Objective indicia of nonobviousness. The Kimmel Declaration (EX2014) contains a heading that "Evidence of Copying Supports the Multilayer Appliance Patents' Nonobviousness." The IPR exhibit set also includes a 3M Press Release (2023). Copying, plus the patent's own stress-relaxation/long-term-unloading data (FIGS. 5–8, "Material 2" vs. "Material 1"), are the anticipated WB/Graham factors. Nexus is the battleground: the claimed "invention" is a property window on commercially available materials (Tritan, Texin-class TPUs), so establishing that the claimed advance — as opposed to the commercial product — caused the copying or the performance gain will be difficult.
5. Written description / enablement (reserved, not an IPR issue). The petition expressly reserves § 112 challenges that the claims sweep beyond the soft–hard–soft disclosure (e.g., to ClearCorrect's hard–soft–hard Zendura FLX sheet) for the district court. Note the internal tension: the narrower "consisting of" claims here can't easily be attacked as over-broad on § 112 while simultaneously being attacked as obvious on § 103 — the two postures pull in opposite directions.

8. Bottom line

Prima facie § 103 case — strong as to most claims.

• Tadros is the closest art and is the very art the Examiner used; it supplies the three-layer soft–hard–soft architecture, the copolyester hard layer, the polyurethane soft layers, and the thermoforming method. The Examiner's own rejection concedes the only differences are the specific numeric properties of the two polymers.
• Porter (Tritan) supplies every recited hard-layer numeral and an express, documented motivation (BPA avoidance + known thermoformability/clarity).
• Kalili + Texin 990R supply the soft TPU layer — including the specific commercial material Kalili itself names — plus the higher-modulus/lower-modulus architecture and lamination.
• Wen supplies the multiple-thinner-layers teaching needed for the "third layer" and multilayer-stack dependent claims.

Under KSR / MPEP 2143(A), the combination rests on (i) substitution of a known element for a known purpose with predictable results, (ii) a finite set of identified solutions driven by the BPA design constraint, and (iii) the well-known design principle of subdividing layers — plus inherency of the numeric property windows in the named commercial materials.

Two things prevent a clean "all claims obvious" conclusion:

1. Claim 24 (TPU flexural modulus > 35,000 psi) is not reached by the asserted art, and the record shows Texin 990R sits at ~6,000 psi. It was omitted from every ground for that reason.
2. The analogous-art / "single polymer" challenges to Porter and to the "consisting of" limitation are substantive, not formal, and were resolved only at the reasonable-likelihood stage.

Procedural status as of 2026-04-26: trial instituted (institution date 2025-11-06 per the IPR tracker; Board's discretionary-referral decision was Paper 14 and the institution decision Paper 17, per the earlier section). No final written decision in IPR2025-00821 was found. Institution means the Board found a reasonable likelihood as to at least some challenged claims; it is not a merits holding of obviousness.

Uncertainty flags (all verified-vs-unverified made explicit)

1. The verbatim POSITA definition and the exact POSITA reasoning in the Declaration (EX1007) were not retrieved — the quotations above are from the Petition body and docket text. Confirm before filing.
2. Ground-to-claim assignments (Ground 1 = claims 6, 9, 18, 23, 25–26; Ground 2 = claims 1–7, 9–23, 25–26; Grounds 3–4 = Tadros-based, Wen-added) are taken from the Petition table of contents and the Patent Owner's opposition brief. Ground 3 and 4 claim lists were not retrieved verbatim.
3. Claim 8 does not appear in Ground 2's list; I could not confirm which ground (if any) reaches it. Verify against the Petition's statement of precise relief.
4. The ~90 Shore A hardness of Texin 990R is my reading of the product family, not a retrieved datasheet value. The Petition maps Texin 990R to the "60A to 85D" limitation; verify the exact Shore value and scale against EX1009, because it is dispositive for claims 1, 6, 10, 18 and their dependents.
5. The Board panel (Ogden, Kalan, Powell) is drawn from the IPR tracker's case page for IPR2025-00821 and should be confirmed.
6. The reported July 2026 jury verdict (invalidity of the asserted claims) post-dates the current analysis date and is not relied on here; it is flagged in the earlier section and remains unverified against a primary court document.