US 10973613

I'll search for authoritative records on this specific patent number.

Let me run a couple of targeted follow-ups on litigation and PTAB activity for this exact patent.

US 10,973,613 B2 — Analyst Summary

Important scoping note: I searched USPTO/PTAB-adjacent sources and CAFC 2026 opinion dockets for the literal number 10973613. I found no Federal Circuit 2026 docket or opinion involving patent 10,973,613. The CAFC 2026 decisions involving Align Technology concern different patents (the dental-image/deep-learning patents 11,049,248 and 10,755,409 in Dental Monitoring SAS v. Align Technology). The active adversarial proceeding against the '613 patent is at the PTAB and District Court, not the CAFC. Details and caveats below.

Bibliographic data (from the patent text and Google Patents record)

Provenance: The application is a divisional of U.S. App. Ser. No. 13/470,681, filed 2012-05-14, now U.S. Pat. No. 9,655,691. The record shows related assignments executed 2017-04-19 to Align Technology, Inc. from Covestro Deutschland AG / Covestro LLC (inventors Pudleiner, Meyer, Nickel, and Pehlert), alongside assignments from Li and Chen — i.e., a joint Align–Covestro (formerly Bayer MaterialScience) development.

Abstract (verbatim substance)

A dental appliance for positioning a patient's teeth includes a removable orthodontic tooth positioning appliance having teeth-receiving cavities shaped to directly receive at least some of the patient's teeth and apply a resilient positioning force. The appliance includes a hard polymer layer (having a hard polymer layer elastic modulus) disposed between a first soft polymer layer and a second soft polymer layer (each with a respective soft polymer layer elastic modulus). The hard polymer layer elastic modulus is greater than each of the soft polymer layer elastic moduli. At least one of the first and second soft polymer layers has a flexural modulus of greater than about 35,000 psi.

Independent claims — plain language

Claim 1 — Method of making a dental appliance (single appliance)
A method of making a tooth-positioning appliance, comprising three steps:

1. Provide a sheet having three or more polymer layers, the layers including:
   • a hard polymer layer comprising a co-polyester with a flexural modulus greater than about 150,000 psi; and
   • a soft polymer layer comprising a thermoplastic polyurethane elastomer with an elongation at break greater than about 200% and a hardness from about 60 A to about 85 D;
2. Provide a positive model of the patient's teeth in a target position; and
3. Thermoform the sheet over the positive model to fabricate the appliance as a negative of that model.

In short: a method claim whose novelty lives in the recited material property windows of a multilayer thermoformable sheet (hard co-polyester core + soft TPU layer), not in the thermoforming step itself.

Claim 20 — Method of making a plurality of dental appliances
Same three-layer-or-more sheet with the same hard-layer and soft-layer property requirements, but the method provides a plurality of positive models, each in a target position, and thermoforms the sheet over each model to fabricate a plurality of appliances, each being a negative of at least one model. (Essentially the Claim 1 method scaled to a multi-stage aligner series.)

Dependent claim themes (context, not independent): additional hard-layer resin options (claim 2); hard layer as two or more sub-layers (claims 3, 11, 19); additional soft-layer elastomer options (claims 4); soft layer as two or more sub-layers (claim 5); further hard-layer property minima (claim 6); further soft-layer property minima (claim 7); staging/fabricating a plurality of appliances from digital models (claims 8–10); alternating soft/hard layers and a three-layer sheet (claims 12–14); hard layer adjacent one or more soft layers (claim 15); hard layer sandwiched between the soft layer and a second soft layer (claim 16); co-extruded material (claim 17); appliance thickness 500–1200 µm (claim 18).

Contested proceedings (not CAFC)

• Align Technology, Inc. v. ClearCorrect Operating, LLC, et al., W.D. Tex., Civil Action No. 6:24-cv-00187-ADA-DTG. Align asserted the '613 patent together with '384, '090, '091 (the "Materials Patents") and others against ClearCorrect/Straumann. The Google Patents record also surfaces 6:24-cv-00187 as a Texas Western District case for this family.
• IPR2025-00818, ClearCorrect Operating, LLC v. Align Technology, Inc., filed 2025-04-14, challenging claims 1–22 of the '613 patent. The Board instituted review on 2025-11-06. Grounds include obviousness over Tadros (US 2005/0100853), Kalili (US 2011/0020761), the Texin 990R product sheet, and further in view of Wen (WO 2006/096558) and Porter. Patent Owner's Response was filed 2026-02-20; the scheduling order set Petitioner's reply at DUE DATE 2 (2026-04-24), Patent Owner's sur-reply (2026-06-05), and oral argument (if requested) on 2026-08-07.
• Parallel PTAB proceedings cover related family members: IPR2025-00819 ('384), IPR2025-00820 ('090), IPR2025-00821 ('091), plus IPR2025-00814–00817 on other Align patents.
• Note: the Google Patents page lists the PTAB case with the label "Unified Patents PTAB Data" and "Petitioner" metadata; the underlying petition and institution decision identify the real petitioner as ClearCorrect Operating, LLC. I treat "Unified Patents" there as the data-source label, not the petitioner.

Explicit uncertainty / confidence flags

1. No CAFC 2026 docket located for 10,973,613. My searches returned no appeal, briefing, or opinion bearing this number in 2026. Because the IPR2025-00818 schedule runs into late 2026, any appeal would likely arise only after a final written decision — so absence of a 2026 CAFC docket is consistent with the timeline rather than surprising. I cannot rule out a non-indexed or very recent docket entry.
2. No final written decision in IPR2025-00818 was confirmed by my searches as of this review. The institution decision (2025-11-06) and Patent Owner Response (2026-02-20) are confirmed; the outcome of the IPR is unverified here.
3. Assignee/date data are drawn from the Google Patents record supplied with the request; I did not independently pull the USPTO PatentCenter assignment abstracts for every assignment entry. Treat the Covestro/Aligm assignment detail as recorded but unverified against the original reassignment documents.
4. The patent's own specification (authoritative here) notes performance-testing comparisons — "Material 2" (multilayer) versus an existing "Material 1" — in FIGS. 5–8, and Align's Patent Owner Response links the claimed subject matter to Align's commercial SmartTrack aligner material (commercially introduced 2013). Whether the claims read on SmartTrack specifically is a question for the PTAB/ District Court, not something the face of the patent resolves.

I'll research litigation involving US 10,973,613 using the sources you specified.

Let me dig into the specific district court case and PTAB proceeding identified.

Let me verify whether the '613 patent appears in other actions (ITC, EDTX Angelalign case) and check current status.

Litigation Involving U.S. Patent No. 10,973,613

Important framing note: U.S. 10,973,613 ("the '613 patent") is one member of a large Align Technology family (family ID 49548874) that includes U.S. 9,655,691; 9,655,693; 10,052,176; 11,154,384; 11,648,090; 11,648,091; 11,767,553; 11,766,313; 11,766,314 and others. Several Align lawsuits assert sibling patents from this family but not the '613 patent itself. Below I list only matters where the '613 patent is actually at issue, then note the closely related matters so you don't conflate them.

1. District Court Action — Align Technology, Inc. v. ClearCorrect Operating, LLC, et al.

The '613 patent's role: Align asserts nine patents in this case. ClearCorrect's Preliminary Invalidity Contentions group the '613 patent with U.S. 11,154,384; 11,648,090; and 11,648,091 as the "Materials Patents." Align initially asserted 183 claims across the nine patents, then was ordered to narrow to 100 claims. Claim charts were served as Exhibits "613-01 through 613-29" specifically for the '613 patent. Notably, ClearCorrect's prior-art narrowing disclosure lists U.S. Patent No. 9,655,691 (Li) — the '613 patent's own parent — as a prior-art reference, along with the Zendura FLX and SmartTrack/Bayer products.

• Docket/discovery order: https://www.docketalarm.com/cases/Texas_Western_District_Court/6--24-cv-00187/Align_Technology_Inc._v._ClearCorrect_Operating_LLC_et_al/docs/296.pdf
• Complaint exhibit: https://www.docketalarm.com/cases/PTAB/IPR2025-00820/ClearCorrect_Operating_LLC/04-14-2025-Petitioner/Exhibit-1023-Complaint_for_Damages_and_Injunctive_Relief,_No_624_cv_00187_WD_Tex/
• Invalidity contentions (identifies '613 as a Materials Patent): https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557669](/patent/1557669)/download-documents
• Unified Patents/Google Patents docket link: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A24-cv-00187

2. PTAB Proceeding — ClearCorrect Operating, LLC v. Align Technology, Inc., IPR2025-00818

Align filed a request for discretionary denial (35 U.S.C. § 325(d), Advanced Bionics), arguing the petition recycled art already considered during prosecution (Tadros, Kalili, Texin 990R, DeSimone, etc.) and ignored objective indicia of non-obviousness credited by the examiner. The Director referred the petitions to the Board and declined discretionary denial; Director Review was then denied on March 3, 2026.

• Institution decision: https://www.docketalarm.com/cases/PTAB/IPR2025-00818/ClearCorrect_Operating_LLC_v._Align_Technology_Inc/docs/11-06-2025-Board/Institution_Decision__Grant-17-DECISION_Granting_Institution_of_Inter_Partes_Review_35_USC_%C2%A7_314.pdf
• Director referral decision (lists all eight IPRs): https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557675](/patent/1557675)/download-documents
• Director Review denial (Mar. 3, 2026): https://gaeflexstaging-dot-docketupdate.appspot.com/cases/PTAB/IPR2025-00818/ClearCorrect_Operating_LLC_v._Align_Technology_Inc/03-03-2026-Board/Order_Denying_Director_Review_of_Institution_Decision-29-Order-Denying_Director_Review_of_Institution_Decision/
• Case tracker: https://ai-lab.exparte.com/case/ptab/IPR2025-00818/clearcorrect-operating-llc-v-align-technology-inc

Companion IPRs filed the same day (Apr. 14, 2025) by the same petitioner, none of which involve the '613 patent: IPR2025-00814 (U.S. 10,456,217), -00815 (10,524,879), -00816 (11,369,456), -00817 (10,791,936), -00819 (11,154,384), -00820 (11,648,090), -00821 (11,648,091).

3. Related matters that do NOT involve the '613 patent (flagged to avoid confusion)

• ITC Investigation No. 337-TA-1471, Certain Clear Aligners and Components Thereof — complaint filed by Align Sept. 23, 2025; instituted Dec. 19, 2025. Asserted patents are 11,766,313; 11,766,314; 8,899,977; 12,059,321; 10,980,616; and 11,490,996 — not the '613 patent. Respondents are Angelalign/Wuxi EA entities and USA Angelalign Technology Corp.
• Align Technology, Inc. v. Angelalign Technology Inc., et al., No. 2:25-cv-00804 (E.D. Tex., Judge Rodney Gilstrap), filed Aug. 18, 2025 (amended complaint Sept. 26, 2025). Align asserts 11,154,384; 11,648,091; 8,899,977; 10,980,616; and 11,490,996 — again, not the '613 patent. This case was stayed pending the ITC investigation (order of Jan. 2, 2026).
• ClearCorrect Holdings, Inc. v. Align Technology, Inc., No. 6:24-mc-00487 (W.D. Tex.) — a miscellaneous/ancillary subpoena proceeding transferred from S.D.N.Y., not an infringement action on the '613 patent.

These sibling patents (the '384, '090, and '091) share the '613 patent's specification and priority, so results in IPR2025-00819/-00820/-00821 and in the Angel/ITC actions will be highly relevant to the '613 patent even though the '613 patent itself is not asserted there.

Summary

Yes — litigation is known, in two fora, both involving ClearCorrect/Straumann:

1. Align Technology, Inc. v. ClearCorrect Operating, LLC, et al., No. 6:24-cv-00187-ADA-DTG (W.D. Tex., Waco Div.), filed 2024 — pending; trial scheduled May 11, 2026 (likely slipping to 2027).
2. ClearCorrect Operating, LLC v. Align Technology, Inc., IPR2025-00818 (PTAB), filed Apr. 14, 2025 — instituted Nov. 6, 2025; Director Review denied Mar. 3, 2026; final written decision projected ~Nov. 8, 2026.

Caveats on confidence: (a) I could not verify the exact W.D. Tex. filing date for 6:24-cv-00187 from the retrieved sources; (b) docket data for litigation is inherently lagging, so additional recently filed matters may exist that are not yet indexed; (c) Google Patents' "family has litigation" flag references a family-wide litigation dataset rather than the '613 patent specifically, and I did not obtain non-U.S. (e.g., UPC, China) actions asserting the '613 patent. I found no CAFC appeal involving the '613 patent.

I'll start by reconciling the structured block against the patent page metadata, then search for the proceeding it flags.

Key finding: the structured block says "no PTAB activity," but the patent's own Google Patents page flags IPR2025-00818. Let me verify the proceeding details and current posture.

PTAB proceedings on US 10,973,613 — analyst report

⚠️ Data-conflict flag (read first). The structured "PTAB proceedings on file" block supplied with this task states the ODP API returns no AIA trial proceedings for this patent. That is contradicted by the patent's own Google Patents page, which carries a "Family has litigation / PTAB case" entry reading IPR2025-00818 filed (Pending - Instituted), and by multiple public PTAB dockets. I am therefore proceeding on one live AIA trial and treating the structured block as stale/unisnked, per the instruction to flag proceedings the ODP has not yet indexed and to prefer live sources. Two further corrections to the source data:

• Google Patents mislabels the petitioner. Its "Petitioner: Unified Patents PTAB Data" field is a data-provider attribution (Unified Patents' CC-BY PTAB dataset), not a party. The real petitioner in IPR2025-00818 is ClearCorrect Operating, LLC (Straumann group). No defensive aggregator is in this chain.
• No proceeding number below is invented. Everything asserted is tied to a cited filing, paper number, or docket.

Proceedings overview

One AIA trial proceeding is on file against US 10,973,613 — IPR2025-00818 — and it is active: instituted on 2025-11-06 on all three grounds against all claims 1–22, with no Final Written Decision yet as of 2026-09-30. Breakdown by status: active/pending = 1; claims invalidated by the PTAB = 0; claims sustained by the PTAB = 0; settled = 0; institution denied = 0. The bottom-line defensive posture is therefore "live and dangerous, but materially weakened": the Board has not canceled any claim, so a defendant cannot yet point to a PTAB disposition; however, a W.D. Tex. jury reportedly invalidated the asserted claims of the '613 patent (and three sibling patents) on 2026-07-02, and a PTAB FWD is due on or about 2026-11-08. A defendant today holds a jury invalidity finding plus a fast-approaching FWD, but must not yet treat any claim of '613 as canceled.

IPR2025-00818 — ClearCorrect Operating, LLC v. Align Technology, Inc.

• Type: Inter Partes Review
• Filed: 2025-04-14 (Petition, Paper 1; notice of filing date accorded Paper 5, 2025-05-08)
• Status: Trial Instituted (verbatim from docket; gloss: IPR granted on all grounds, trial underway, no FWD yet)
• Judge panel: Christopher L. Ogden, Kristina M. Kalan, Neil T. Powell (APJs) — sourced from the Ex Parte aggregator's panel listing; I could not confirm against the face of the institution decision itself, so treat the panel composition as secondary-source.
• Petition grounds — all under 35 U.S.C. § 103, all 22 claims challenged (claims 1 and 20 independent):
  • Ground 1 — claims 1–2, 4, 6–10, 12–18, 20–22 obvious over Tadros (US 2005/0100853) in view of Kalili (US 2011/0020761) and the Texin 990R data sheet.
  • Ground 2 — claims 3, 5, 11, 19 obvious over the Ground 1 combination further in view of Wen (WO 2006/096558).
  • Ground 3 — claims 1–12, 15, 18–22 obvious over Kalili in view of Porter (Tritan copolyester reference, as characterized in the petition) and Wen, further in view of Texin 990R.
  • No § 102 anticipation ground and no § 112 ground were asserted.
• Institution decision: Instituted in full — 2025-11-06 (Paper 17, "DECISION Granting Institution of Inter Partes Review 35 U.S.C. § 314"). The panel found Petitioner established a reasonable likelihood of prevailing on at least one challenged claim and instituted on all three grounds ("we are persuaded that Petitioner has met its burden on this record for institution on the basis of Ground 2," etc.). Procedural context: the Director's discretionary-denial request had already been denied and the petition referred to the panel (Paper 14, 2025-08-29), on the reasoning that "there is evidence in the record indicating that the Office erred in a manner material to patentability" — specifically that the examiner allowed "broad limitations directed to various polymer layers" while "substantially similar limitations in child applications were rejected over prior art." The Board also authorized a Petitioner reply and Patent Owner sur-reply on the preliminary record (Panel email, 2025-09-10; reply 2025-09-17, sur-reply 2025-09-24, 5 pages each).
• Final Written Decision (if issued): NONE as of 2026-09-30. No claim of the '613 patent has been canceled, and none has been sustained, by the Board. Do not represent otherwise. The projected FWD due date of record is 2026-11-08 (as recited in the Director's 2025-08-29 referral decision), consistent with the § 316(a)(11) one-year deadline running from the 2025-11-06 institution date.
• Settlement / termination: No settlement and no termination. The closest event is Align's 2026-03-11 email request for authorization to file a motion to vacate the institution decision and terminate IPR2025-00818/-00819/-00820/-00821 on the ground that the petitions failed to name Bay Materials LLC as a real party in interest (a Straumann company and the supplier of the accused Zendura FLX material). ClearCorrect opposed, arguing it was "an untimely second rehearing request." The Board denied the filing request on 2026-03-26 (Paper 31, Order Denying Patent Owner's Filing Request, 37 C.F.R. § 42.5). The proceeding continues.
• Director review (pre-institution stage): Align filed a Request for Director Review on 2025-11-20 (Paper 19), challenging both the discretionary-denial referral and the institution decision and raising the Bay Materials RPI issue. Denied without explanation on 2026-03-03 (Paper 29, Director John A. Squires), applying to -00817, -00818, -00819, -00820 and -00821.
• Appeal: None. There is no FWD to appeal, so no Fed. Cir. docket exists. The RPI / § 312(a)(2) and § 325(d) issues Align pressed are preserved and could resurface on appeal from any adverse (or even favorable-but-narrowed) FWD.
• Defensive value: This is a full-scope attack on all 22 claims by a direct competitor (ClearCorrect/Straumann), instituted on all grounds — meaning the Board, and separately the Director, both found the Office likely erred in allowing these claims. For a defendant being asserted today, IPR2025-00818 is the single best invalidity roadmap on the patent, and if an FWD cancels any of claims 1–22, § 315(e)(2) estoppel will bind ClearCorrect and its privies but not you. Until the FWD issues (due 2026-11-08), however, a defense built solely on "the PTAB will kill it" is premature — Align's Patent Owner Response (Paper 27, 2026-02-20) is aggressively contesting every ground and stacking objective indicia (SmartTrack commercial success, industry copying).

Strategic summary

Claim status across the '613 patent. As of 2026-09-30 the PTAB has canceled nothing and sustained nothing. All 22 claims (1–22) are under challenge and untested at the Board; there are no unchallenged claims on this patent — the petition attacks the full claim set. The only claim-level adverse finding on the record is from the parallel district court, not the PTAB: press reports of the W.D. Tex. jury verdict of 2026-07-02 in Align Technology, Inc. v. ClearCorrect Operating, LLC, No. 6:24-cv-00187-ADA-DTG, state that the jury found ClearCorrect's ClearQuartz/Zendura FLX aligners infringed but found the asserted claims of US 10,973,613, US 11,154,384, US 11,648,090 and US 11,648,091 invalid under the clear-and-convincing standard (and, as a result, never reached damages; the antitrust counterclaims failed at the market-definition step). Caveat: I could only verify that verdict through secondary, largely non-English press summaries — I could not retrieve the verdict form or the judgment from the docket, so do not treat it as confirmed. What is confirmed on primary documents is the pre-trial posture: the court set a 2026-05-27 motion hearing (order signed 2026-05-21) on ClearCorrect's motion for preclusion, Align's partial motion for summary judgment of validity, and ClearCorrect's summary-judgment motion of invalidity under § 101.

Estoppel landscape. No § 315(e)(2) estoppel has attached yet, because estoppel runs from a final written decision. When (and if) the FWD issues, it will bind ClearCorrect Operating, LLC, ClearCorrect Holdings, Inc., Institut Straumann AG and Straumann USA, LLC — the four RPIs ClearCorrect identified (Pet. 74) — from raising in the district court any ground they raised or reasonably could have raised. It will not bind unrelated defendants, and Align's pending RPI theory (that Bay Materials LLC is an unnamed RPI and therefore also a privy) is unresolved but has been preserved: the Director declined review and the Board declined to authorize a vacatur motion. For a defendant being asserted today, the practical implication is that the entire field of § 102/§ 103 art on the '613 claims remains available to you unless you are in privity with ClearCorrect/Straumann. The art already spent in the IPR (Tadros, Kalili, Wen, Porter, Texin 990R, plus the Zendura/Durasoft/Imprelon/Desmopan product literature listed in ClearCorrect's district-court narrowing disclosure) is the art most likely to draw an Align Advanced Bionics/§ 325(d) or IPR-filing-bar response, so new art and § 112/§ 101 theories carry more marginal value.

Pattern signals. This is a coordinated eight-petition campaign by a single petitioner group, not an isolated challenge: ClearCorrect filed IPR2025-00814, -00815, -00816, -00817, -00818, -00819, -00820 and -00821 against eight Align patents — 10,456,217; 10,524,879; 11,369,456; 10,791,936; 10,973,613; 11,154,384; 11,648,090; 11,648,091 (per Align's consolidated Power of Attorney, 2025-05-01). The four multilayer-material patents in that set ('613, '384, '090, '091) are the same family as the patent at issue here — continuation/divisional siblings — so a defendant asserting the '613 patent will very likely face the '384, '090 and '091 patents too, and should build a family-wide invalidity strategy rather than a '613-only one. There is also an earlier Bay Materials challenge (IPR2022-01214) cited repeatedly in the record as concerning multilayer aligner material and Zendura FLX; I could not confirm which family member that petition targeted, so I am not treating it as a proceeding against '613. Align itself is a heavy PTAB and ITC user on the other side of this family: it filed an ITC § 337 complaint on 2025-09-23 against Angelalign entities on "multilayer materials for clear aligners" and bite-ramp/power-ridge features (instituted 2025-12-19, with a 14.7-month target date of 2027-03-22, an evidentiary hearing on 2026-07-20 to -24, and an expected initial determination by 2026-11-20) — a signal that Align is monetizing this family across forums and that the '613 family is the tip of a multi-patent assertion program.

Recommended next steps

1. Pull the live docket before relying on any of this. Track IPR2025-00818 via USPTO PTAB E2E / the PTAB public docket at https://ptacts.uspto.gov/ptabs/ and the aggregate docket at https://www.docketalarm.com/cases/PTAB/IPR2025-00818/ClearCorrect_Operating_LLC_v._Align_Technology_Inc/. The last event I could verify is the 2026-03-26 order denying Align's filing request; anything after that (supplemental evidence, motion to amend, oral hearing notice) was not in my indexed sources and should be checked directly.
2. Calendar the FWD deadline. The projected FWD due date is 2026-11-08 — roughly six weeks from today. That is the single most important date for your case: a FWD canceling claims 1–22 (in whole or in part) converts this patent from "live" to "degraded," and the institution decision (Paper 17, 2025-11-06) quotes the exact limitation-by-limitation mapping you can reuse. If the FWD goes Align's way, expect Align to cite the surviving claims against you immediately.
3. Do not cite any claim as canceled. No PTAB claim of US 10,973,613 is canceled. If you are drafting a demand-letter response or an invalidity contention, ground it in the jury invalidity verdict (2026-07-02, allegedly) and in your own prior art — and verify the verdict and the entry of judgment docket-side (W.D. Tex. 6:24-cv-00187, ECF) before relying on it, since Align will surely move for JMOL and appeal an adverse judgment. Link any judgment you cite rather than the press summary.
4. Preserve your own art and pick your forum deliberately. Because § 315(e)(2) estoppel will not bind you, you retain the full prior-art field. But note the § 325(d) hazard: Align has successfully argued Office error as a reason not to discretionarily deny, and the same Tadros/Kalili/Wen/Porter/Texin art has now been fully briefed. Fee-shifted value is highest in new art combinations or in statutory defenses the IPR cannot reach (§ 112 written description/enablement of the claimed polymer property ranges, and § 101), which the IPR cannot adjudicate and which ClearCorrect has been running in parallel.
5. Treat the family as the unit of defense. Petition the '384, '090 and '091 patents (IPR2025-00819/-00820/-00821) as a set if you are a target; Align's ITC action against Angelalign on "multilayer materials" confirms it will assert the whole family, not just '613. Coordinating your invalidity theory across all four will avoid the multiple-petition discretionary-denial trap and the Director's multiple-petition precedent now being litigated in the Round One/Round Two proceedings.

Sources: Google Patents US10973613B2 (metadata, family, litigation flags, fetched 2026-09-30); IPR2025-00818 Petition (Paper 1, 2025-04-14) and Institution Decision (Paper 17, 2025-11-06); Patent Owner Response (Paper 27, 2026-02-20); Director Discretionary Decision Refer (Paper 14, 2025-08-29); Order Denying Director Review (Paper 29, 2026-03-03); Order Denying Patent Owner's Filing Request (Paper 31, 2026-03-26); Board/party email exhibits 3001–3002; W.D. Tex. 6:24-cv-00187 docket entries including the 2026-05-21 order setting the 2026-05-27 hearing; Align Technology SEC filings and press summaries of the 2026-07-02 verdict (secondary, unverified).

I'll research the assignment record and ownership chain for US 10973613. Let me start with several parallel searches.

Excellent — rich results. Let me dig deeper on the assignment reel/frame records and the correspondent details.

Ownership & Assignment Analysis — US 10,973,613 B2

Patent: US 10,973,613 B2 — "Multilayer dental appliances and related methods and systems"
App. No.: 15/476,655 (filed 2017-03-31); divisional of 13/470,681 (now US 9,655,691)
Priority: 2012-05-14 | Granted: 2021-04-13 | Adjusted expiry: 2032-10-11

Data note (read first): Four assignment events are indexed for this family, but the public aggregators I could reach (Google Patents legal events, prosecution-history exhibits) publish the parties, conveyance type and recording date only — they do not expose the USPTO reel/frame. I could not retrieve reel/frame numbers, and I will not fabricate them. Everything below is dated and sourced; the reel/frame cells must be verified directly at the USPTO Assignment Center by patent number. Where I could not confirm a field, I say so.

Inventors

Pattern note — a co-development, not a fire-sale. This is a joint Align × Bayer MaterialScience (now Covestro) invention. The two named Align inventors (Li, Chen) and the four polymer-chemist inventors employed by Covestro each assigned to their respective employers, and Covestro then conveyed its half to Align — the standard clean-up used to consolidate title in one owner. This is not a case of inventors departing a distressed assignee shortly before a portfolio sale: there is no evidence of any inventor departure, and no sale event occurred. The Covestro-side inventors sit at a large, solvent German materials company (Covestro AG), which is itself a different and much cleaner fact pattern than the "all inventors exit within 12 months" tell the brief describes.

Original assignee

Align Technology, Inc. (Delaware corporation; 2560 Orchard Parkway, San Jose, CA 95131 per the recorded assignment instrument). Align is the assignee named on the face of US 10,973,613 and remains the owner.

• Primary line of business: clear aligner systems and intraoral scanners — the Invisalign® System and iTero scanners. Publicly traded (NASDAQ: ALGN), SEC-reporting, operating company.
• Does it ship a product embodying the claims? Yes. The claims recite a multilayer thermoformed shell having a hard co-polyester layer (flexural modulus >150,000 psi) and a soft thermoplastic-polyurethane-elastomer layer (elongation at break >200%; hardness 60 A–85 D). This is the material that Align commercialized in its multilayer aligner stock (the "SmartTrack"-era multilayer film). Align's own infringement contentions (served 2024-07-18 in the W.D. Tex. action) identify the multilayer film as the accused-against comparator, showing Align treats the claims as covering commercially shipped aligner material.
• Current status: Operating. No bankruptcy, no dissolution, no acquisition of Align. The entire sibling family (US 9,655,691, 11,213,369, 11,154,384, 11,648,090, 11,648,091, 11,764,809, 11,766,313, 11,766,314, 12,324,722, and pending 2025/0134627) is held by Align Technology, Inc.

Assignment timeline

Assignment Center records exist for this patent. (They are inheritable from the parent 13/470,681 and its continuations.) The publicly indexed events are below. Reel/frame could not be confirmed from the sources available to me and is flagged accordingly.

• 2012-05-01 / 2012-05-16 (executed; notary attested 2012-05-16) — recorded 2017-04-19 — Reel/Frame not retrieved

  • Conveyance: Assignment (inventor → employer)
  • Assignor: Chunhua Li; Yan Chen (recorded addresses: 19688 Vicksburg Dr., Cupertino, CA 95014; 10461 Pineville Ave., Cupertino, CA 95014)
  • Assignee: Align Technology, Inc.
  • Correspondent: Wilson Sonsini Goodrich & Rosati (WSGR) — "Align Technology, Inc. / WSGR, 650 Page Mill Road, Palo Alto, CA 94304" appears as the attorney/correspondent of record on the family's filings (e.g., ADS and prosecution papers of continuations 17/214,487 and 17/858,825). Recurs across the chain — WSGR is Align's routine outside patent counsel, i.e., an operating company's regular prosecution firm, not an NPE-filing lawyer. (Attorney docket on the instrument: 83289-831160 / 022900US.)
  • Context: Internal / original employment assignment — funding engineers' rights to the company.

• 2017-04-19 (recorded) — Reel/Frame not retrieved — Reel/Frame not retrieved

  • Conveyance: Assignment
  • Assignor: Heinz Pudleiner; Klaus Meyer; Joerg Nickel
  • Assignee: Covestro Deutschland Aktiengesellschaft (Kaiser-Wilhelm Allee 60, D-51373 Leverkusen, Germany)
  • Correspondent: not determinable from available sources
  • Context: Internal — Covestro-side inventors assign to their employer.

• 2017-04-19 (recorded) — Reel/Frame not retrieved

  • Conveyance: Assignment
  • Assignor: Craig Pehlert
  • Assignee: Covestro LLC (c/o Covestro CIC, Pittsburgh, PA 15203)
  • Correspondent: not determinable from available sources
  • Context: Internal — Covestro-side inventor assigns to his employer.

• 2017-04-19 (recorded) — Reel/Frame not retrieved

  • Conveyance: Assignment (consolidation of co-owner's rights)
  • Assignor: Covestro Deutschland Aktiengesellschaft and Covestro LLC
  • Assignee: Align Technology, Inc.
  • Correspondent: not determinable from available sources (Align-side recording; WSGR is Align's counsel of record)
  • Context: Consolidation of co-ownership into the operating company. Instrument recites that the application "names inventors from Assignor 1, Assignor 2 and Assignee," who "assigned their invention to their respective company," and confirms Align as sole assignee. Corroborated verbatim in the prosecution history of 17/858,825 (exhibited as EX1017 in ClearCorrect v. Align, IPR2025-00820). Not a sale, securitization, or transfer to an asserter.

No other recorded assignments exist. Everything after 2017 is internal prosecution (continuations/divisionals) within the same owner. There is no post-issuance transfer to any third party, licensing entity, or aggregator.

Timeline diagram

timeline
    title Ownership of US 10973613
    2012 : Filed by Align and Covestro inventors
         : Align inventors assign rights to Align
    2017 : Covestro inventors assign to Covestro
         : Covestro assigns its rights to Align
    2021 : Patent issued to Align Technology
    2024 : Align sues ClearCorrect for infringement
    2025 : ClearCorrect files IPR2025-00818

NPE / troll-pattern signals

Litigation / challenge posture (context for signals 5 and 7):

• Assertion: Align Technology, Inc. v. ClearCorrect Operating, LLC, ClearCorrect Holdings, Inc., Institut Straumann AG, and Straumann USA, LLC, No. 6:24-cv-00187-ADA-DTG (W.D. Tex., filed 2024-04-11). Align asserts the '613 patent (asserted claims 1, 3, 4, 6–10, 12–15, 17, 18, 20, 22) together with eight other Align patents against a direct competitor in clear aligners.
• PTAB: ClearCorrect Operating, LLC filed IPR2025-00818 against the '613 patent on 2025-04-14; instituted 2025-11-06 (part of a coordinated set of ClearCorrect IPRs, incl. -00816/-00817/-00820). The challenger is the competitor, not an NPE.
• Reported outcome: A W.D. Tex. jury verdict dated 2026-07-02 reportedly found ClearCorrect's ClearQuartz/Zendura FLX multilayer aligners infringe, but held the asserted claims invalid; the PTAB IPRs remained pending. (Treat as reported, not final on appeal.)

Verdict

Operating-company assertion.

Align Technology, Inc. is the current assignee under the recorded 2017-04-19 consolidation (Covestro Deutschland AG + Covestro LLC → Align), and has held the patent since the 2012 inventor assignments; it is a NASDAQ-listed manufacturer that ships Invisalign aligners embodying the claimed multilayer sheet, and it is asserting the '613 patent directly against a product competitor (ClearCorrect/Straumann) in Align v. ClearCorrect, No. 6:24-cv-00187 (W.D. Tex.). None of the eight NPE signals is present — there is no shell-entity transfer, no known asserter, no cascading LLC chain, no pre-litigation assignment, and no defensive-aggregator termination. This is a classic product company enforcing its own manufacturing patent, the inverse of the NPE pattern.

Caveat: reel/frame numbers could not be confirmed from the sources available to me and should be verified directly.

Verify at: USPTO Assignment Center → https://assignmentcenter.uspto.gov/ (search Patent Number 10973613; also cross-check the parent 9655691 and siblings 11213369 / 11154384) — see also https://patents.google.com/patent/[US10973613B2](/patent/US10973613B2)/en (Legal Events) and the recorded instruments exhibited in IPR2025-00820 (Ex. 1017, prosecution history of 17/858,825).

I'll research this systematically — first confirming the patent record and its cited references, then examining each reference.

I have the PTAB grounds. Now let me get the actual "References Cited" list from the face of the '613 patent.

Prior-Art Analysis — US 10,973,613 B2

0. Scope, provenance, and one flagged conflict

Identity confirmed (do not substitute): US 10,973,613 B2, "Multilayer dental appliances and related methods and systems," App. No. 15/476,655, filed 2017-03-31, granted 2021-04-13, 22 claims (independent claims 1 and 20), assignee Align Technology, Inc. This is a divisional of App. No. 13/470,681 (now US 9,655,691).

Critical date rule I applied: the effective filing date is the 2012-05-14 parent filing. Because that date precedes 2013-03-16, the pre-AIA version of 35 U.S.C. § 102/§ 103 governs. This matters: pre-AIA § 102(b) gives a one-year bar; pre-AIA § 102(e) lets certain US patents/publications act as art as of their US filing date. References dated after 2012-05-14 are generally not § 102 art here absent an earlier § 102(e) date — I flag those below rather than silently treating them as prior art.

Two honest limitations on what I could retrieve:

1. The "References Cited" enumeration on the face of the '613 patent was only partially recoverable from my searches (the front-page OCR surfaced as date-ordered fragments — Kesling, Witsiepe, Duret, Schudy, etc. — without every patent number). I therefore distinguish (A) references I could cite with a verified number/date, from (B) front-page references I can only characterize generically. I did not fabricate numbers to fill the gap.
2. Date conflict worth flagging: the task states the current date as April 26, 2026. The '613 IPR (IPR2025-00818) schedule you previously generated runs to oral argument 2026-08-07, with a final written decision due thereafter. If the operative "today" is in fact later in 2026, a final written decision in IPR2025-00818 may already exist and I could not verify it. My analysis below rests on the record as of the institution decision (2025-11-06) and the Patent Owner Response (2026-02-20).

No contradiction with the previously generated summary was found; the prior section's identification of the art (Tadros / Kalili / Texin 990R / Wen / Porter) and its § 103 framing match what I independently retrieved.

1. The claims that the art actually has to reach

Because "anticipation" is claim-specific, restating the load-bearing limitations of the two independent claims:

• Claim 1 (method, single appliance): (i) sheet with three or more polymer layers; (ii) hard layer comprising a co-polyester with flexural modulus > ~150,000 psi; (iii) soft layer comprising a thermoplastic polyurethane elastomer with elongation at break > ~200% and hardness ~60 A to 85 D; (iv) positive model of teeth in a target position; (v) thermoforming the sheet over the model.
• Claim 20 (method, plurality): same (i)–(iii) sheet, plus a plurality of positive models and thermoforming to form a plurality of appliances.

Everything else (claims 2–19, 21–22) is dependent.

2. The asserted prior art in IPR2025-00818 (ClearCorrect Operating, LLC v. Align Technology, Inc.)

These are the references the Board instituted on 2025-11-06. All three grounds are § 103 obviousness, not § 102.

Instant-read on § 102: the petition's own framing confirms it — the references are combined. Align's Response (2026-02-20) attacks exactly this: it argues the petition's "Tadros discloses a soft-hard-soft copolyester/TPU appliance" premise is "riddled with errors," starting with the assertion that PCCD is a copolyester. That is a § 103 fight, not a § 102 case.

3. Additional references cited during prosecution (PTO-892 / IDS record)

Retrieved from the prosecution histories of the '613 and its siblings (Ex. 1010–1011, Ex. 1017), plus ClearCorrect's narrowing disclosure. These were cited by the Examiner or submitted by Align, mostly in § 103 combinations, several with an explicit "does not specifically disclose the recited physical properties" finding.

Front-page historical citations (partial): the patent's face cites a long chain of tooth-positioning/orthodontic patents — including Kesling (1949, 1968, 1980), James (1971), Lawrence (1972), Melvin (1972), Cohen et al. (1973), Witsiepe et al. (1973), Levine (1975), Schudy (1975), Lavin (1975), Bergersen (1976), Dellinger (1977), Coles et al. (1981), Heitlinger et al. (1982), Arcan et al. (1982), Hornbaker et al. (1982), Kurz (1982), Matsumoto et al. (1983), Barrut (1984), Yoshii (1985), Moermann et al. (1986), Andrews (1986), Duret et al. (1986–88), Abbatte et al. (1988), Halverson et al. (1988). These are background/analogous-art citations for the orthodontic-appliance field. None of them discloses a multilayer co-polyester/TPU sheet with the recited mechanical-property windows, so none can anticipate. I could not recover every patent number in that list and have not guessed at them.

4. § 102 anticipation analysis, reference by reference

Framing point: No reference of record discloses, in a single document, all of: (a) a three-or-more-layer sheet, (b) a co-polyester hard layer with flexural modulus >150,000 psi, (c) a TPU soft layer with elongation at break >200% and Shore 60 A–85 D, and (d) thermoforming over a positive model of teeth in a target position. Accordingly, no reference anticipates claims 1 or 20 under § 102, and correspondingly none anticipates any of claims 2–22 (each depends from 1 or 20). The challenges are, and were pleaded as, § 103.

Per-reference close-call analysis:

• Tadros '853 — closest on structure, not on chemistry. It reaches the soft-hard-soft multilayer dental appliance and even the thermoforming step, and the petition maps every limitation of claim 1 except the soft-layer property recitals onto it. But (i) Tadros' hard layer is a polymeric blend, and (ii) Align's Response asserts its PCCD is a cycloaliphatic polyester homopolymer, not a co-polyester, citing Tadros' own § [0022], [0024], [0050]–[0051]. Under § 102, "comprising a co-polyester" would fail. Conclusion: no anticipation of claims 1/20.

• Kalili '761 + Texin 990R datasheet — closest on the soft-layer properties. Kalili teaches a lower-modulus tooth-contacting lining and names Texin 990R; the Texin 990R sheet supplies the numerical values (elongation >200%, Shore range). But Kalili is two layers and uses polycarbonate, not co-polyester, and the datasheet is not a dental appliance. No anticipation.

• Porter (Tritan) — closest on the hard-layer properties. Supplies a copolyester meeting the flexural-modulus recital, but is a materials article, not an appliance. No anticipation.

• Wen '558 — process teaching only. Multiple thin sub-layers. No anticipation.

• DeSimone '841, Wheeler '675, Wrosz '703, Adell '575, Hinz '419, Bedard '075 — material/process fragments, each expressly found by the Examiner to lack "the recited physical properties" or to address a different step. No anticipation individually.

• Datasheets and commercial products — printed publications or on-sale/public-use facts as to materials, not as to the claimed method. No anticipation.

• Post-priority references (Stewart-464, Stewart-511, Pudleiner '124, Rafih '903, and the 2013-era SmartTrack product) — cannot be § 102 art against a 2012-05-14 pre-AIA priority date unless a verified earlier § 102(e) filing date exists. Treat any anticipation theory built on them as unavailable pending verification.

5. Forward citations (for completeness; relevant to validity, not § 102)

Three documents cite the '613 patent: US 11,213,369 B2 (Align, 2022-01-04 — same family, "Multilayer polymer sheets"), US 12,226,981 B2 (Bay Materials LLC, 2025-02-18, "Dual shell dental appliance and material constructions"), and US 12,588,977 B2 (Bixby International Corporation, 2026-03-31, "Dental aligner"). The Bay Materials and Bixby documents are a different inventive lineage (dual-shell constructions) and are irrelevant as § 102 art to the '613 claims, but they are useful evidence of the crowded post-2012 multilayer-aligner field and of how the '613 disclosure is being distinguished.

6. Bottom line

Confidence flags: (1) I could not retrieve the full verbatim PTO-892 list from the '613 front page; the table in § 3 is compiled from the family prosecution histories and ClearCorrect's narrowing disclosure, and each entry should be verified against the printed front page before being relied on. (2) Dates for Stewart-464/511, Rafih '903, and Pudleiner '124 must be checked against § 102(e) — on their faces they are not prior art to a 2012-05-14 priority date. (3) The IPR2025-00818 final written decision is unverified; if the operative date is later than April 2026, it may have issued, and the art analysis could have narrowed or expanded accordingly.

I'll research the prior art references identified in the IPR petition and prosecution history before performing the §103 analysis.

Let me verify the remaining references (Porter, DeSimone/§102/§103 prosecution history) to ground the analysis.

Obviousness Analysis — U.S. 10,973,613 B2 under 35 U.S.C. § 103

Building on the earlier summary and litigation sections. I do not repeat the bibliographic data, the claim-1/claim-20 plain-language restatement, or the litigation posture; the analysis below assumes them. Where a conclusion rests on something not verified in the record, I flag it.

1. Framing: which § 103 applies, and the critical date

• The '613 patent issues from Application No. 15/476,655 (filed 2017-03-31), a divisional of 13/470,681, filed 2012-05-14. Because the earliest effective filing date is 2012-05-14 — before the March 16, 2013 AIA first-inventor-to-file cutoff — the pre-AIA § 103(a) framework governs (prior art under pre-AIA §§ 102(a)/(b)/(e)). The petitioner in IPR2025-00818 framed Texin 990R as prior art "under at least pre-AIA 35 U.S.C.," which is consistent with this reading.
• Every reference relied on predates 2012-05-14, so the analysis is stable regardless of whether the '613 claims are ultimately accorded the 2012 priority date. (If any claim were held not entitled to 2012 support, the critical date would move later, adding still more art — including Align's own parent U.S. 9,655,691, which ClearCorrect has already listed in its invalidity contentions. That is a one-way ratchet against patentability; I flag it as unverified, however, since I did not independently audit the written-description support.)
• Pre-AIA § 103(a) is applied under Graham v. John Deere and KSR Int'l v. Teleflex: (i) scope/content of the prior art; (ii) differences from the claims; (iii) PHOSITA level; (iv) secondary considerations. KSR forecloses the rigid TSM test — a motivation may be found in "common sense," market pressure, design incentives, and "known techniques to improve similar devices in the same way."

Level of ordinary skill (POSITA): a person with at least a bachelor's in polymer science/materials/mechanical engineering (or equivalent), plus ~2–3 years' experience formulating or thermoforming multilayer polymer films for dental/medical devices, or a master's with less experience. This is a mature, crowded, materials-selection art — exactly the setting where KSR and In re Best reasoning bite hardest.

2. The analytical core: claim 1's novelty lives in numerical property windows

As previously summarized, claim 1 is a method whose only unconventional matter is the recited material-property windows of a multilayer sheet:

Three patentability-significant consequences follow from this claim architecture:

1. Claim 1 is markedly broader than the specification's sole embodiment. The specification describes only the soft–hard–soft sandwich (hard layer between two soft layers). Claim 1 does not require that arrangement — only three-or-more layers including a hard co-polyester layer and a soft TPU layer. The "hard between two softs" limitation appears only in dependent claim 16. This materially lowers the invalidity bar: the art need only disclose a 3+ layer sheet containing one high-modulus co-polyester layer and one high-elongation TPU layer.
2. "Comprising" is open-ended. A layer that contains a co-polyester — even as one component of a blend — meets (b). This matters because the primary reference, Tadros, discloses blends (e.g., PC/PETG) rather than neat resins. The "consisting of" objection Align advanced against Tadros in the sibling-patent files (see https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557674](/patent/1557674)/download-documents — "fails to specifically disclose … at least one layer consisting of the specified copolyester") does not defeat claim 1 of the '613 patent, which uses "comprising."
3. The limitations are all result-effective material variables — flexural modulus, elongation at break, Shore/D hardness — that the prior art already ties to aligner function (repositioning force vs. comfort/root-damage avoidance). Under KSR, selecting a known material within a disclosed class to achieve its known properties is an obvious design choice, and a recited numerical range that overlaps or is encompassed by the prior art's disclosed range or value is prima facie obvious (In re Wertheim, In re Woodruff, In re Best — where a reference discloses a composition, later-recited inherent properties are presumed present).

A threshold point worth stating plainly: no single reference anticipates, because the specific property-manifesting commercial materials are spread across the art. The '613 patent is therefore an obviousness (combination) case, not an anticipation case — and the combinations are strongly evidenced.

3. The prior-art references

4. Ground 1 — Tadros + Kalili + Texin 990R

(Claims 1–2, 4, 6–10, 12–18, 20–22)

This is the primary ground and mirrors the instituted Ground 1 in IPR2025-00818 (see https://ai-lab.exparte.com/case/[ptab](/ptab)/IPR2025-00818/doc/1005).

Element mapping for claim 1:

• (a) 3+ layer sheet, hard + soft layers → Tadros discloses a sheet with two or more layers (one an elastomer), plus a first and optional second additional layer on opposed surfaces ([0016], [0073], cls. 16–17) — i.e., a soft–hard–soft stack. Notably, the petitioner described soft–hard–soft as "the sole configuration described in the '613 specification."
• (b) hard co-polyester layer, flexural modulus > ~150,000 psi → Tadros discloses hard layers from polycarbonate–co-polyester blends including PETG, with tensile moduli reported in the 1,600–1,900 N/mm² range (234,000–278,000 psi) — comfortably above 150,000 psi. Because claim 1 uses "comprising," a blend containing a co-polyester satisfies this limitation.
• (c) soft TPU layer with elongation > ~200% and hardness 60A–85D → Kalili names TEXIN 990R as the soft liner; the Texin 990R sheet supplies 450% ultimate elongation (>200%) and 90A hardness (within 60A–85D).
• (d)–(e) positive model + thermoforming → Tadros discloses exactly this: forming a sheet and thermoforming over a replica of the patient's teeth, producing a negative of the model, with staged appliances.

Motivation to combine (the heart of the ground):

• Tadros and Kalili are in the same field and address the same problem — removable multilayer orthodontic aligners that apply repositioning force while limiting harm to teeth/gums. Combining references drawn from the same art for the same purpose is the paradigm KSR case.
• Kalili supplies an express, articulated reason to choose the specific material: it identifies TEXIN 990R by name and lauds its "outstanding abrasive resistance, impact strength, toughness, structural memory and flexibility," and its lower-modulus inner lining as reducing localized pressure and root/bone resorption. A POSITA wanting a compliant, durable soft layer for Tadros's appliance would be led directly to Texin 990R.
• Tadros itself supplies the structural motivation for soft surfaces — a softer layer contacting the gums "can be used effectively to alleviate pain, discomfort and bleeding gums."
• Reasonable expectation of success: using a commercially documented TPU as the compliant layer of a thermoformed dental appliance is a substitution of one known elastomer for another in an identical end use, yielding predictable mechanical behavior. No new operability question is raised.

Anticipated counter-argument and response: Align argued (in the sibling files) that Tadros discloses blends, and so fails to suggest a layer "consisting of" a copolyester combined with a TPU layer. For the '613 claims this is largely a non-sequitur, because claim 1 says "comprising," not "consisting of."

5. Ground 2 — Tadros + Kalili + Texin 990R + Wen

(Claims 3, 5, 11, 19 — multiple sub-layer limitations)

Claims 3, 5, 11, and 19 require the hard and/or soft layer to itself comprise at least two laminated or co-extruded layers.

• Wen supplies the missing teaching: it discloses multilayer dental aligners and teaches that substituting multiple thinner sub-layers for a single thick layer improves conformity to the tooth model and interlayer bonding/adhesion (Wen is cited in the record as providing "a general principle for improving the fabrication of multilayer appliances").
• Motivation: a POSITA seeking better tooth-conformity and layer adhesion — both directly tied to aligner fit and force delivery — would replace Tadros's single hard core with two or more thinner layers of the same material. Since splitting a layer does not change aggregate flexural modulus (total thickness unchanged), the reasonable expectation of success is high: the repositioning-force profile is preserved while manufacturing fidelity improves.

6. Ground 3 — Kalili + Porter + Wen + Texin 990R

(Alternative route to claims 1–12, 15, 18–22)

An independent, non-Tadros path that the Board also instituted (Ground 3 of IPR2025-00818):

• Kalili = base: a multilayer aligner with a hard polycarbonate outer layer + lower-modulus TPU (Texin 990R) inner lining; the appliance is made by laminating the polyurethane to the polycarbonate sheet. Kalili expressly generalizes to "any type of polymers with higher modulus outer layer and a lower modulus inner layer."
• Porter = the co-polyester hard layer: teaches replacing polycarbonate with Tritan copolyester, which delivers flexural modulus 225,000 psi (>150,000) and the full property suite of claim 6 (tensile strength @ yield 6,200 psi; elongation @ yield 6%; elongation @ break 210%; total transmittance 90%). Porter supplies the explicit motivation — avoid BPA, and avoid environmental stress cracking that afflicts polycarbonate "particularly in more intricate shapes" (like aligners), while thermoforming faster and at lower temperatures.
• Wen = the 3+ layer requirement and sub-layer splitting, as in Ground 2. The combination yields a soft–hard–hard or soft–hard–soft multilayer sheet with a Tritan co-polyester hard layer and a Texin 990R soft layer.
• Texin 990R = soft-layer properties, as above.

Motivation: Porter's BPA-avoidance and ESC-resistance rationale is strongly pertinent to the problem — an intraoral appliance is continuously exposed to moisture, elevated temperature, and hydrolytic/enzymatic attack, the exact conditions Porter identifies as driving Tritan's advantages. Porter also states Tritan "thermoforms well with deep draws" and is used in "extruded sheet applications prior to thermoforming," matching the '613 fabrication sequence.

Expected counter-argument (non-analogous art): In its Director Review Request, Align characterized Porter as "non-analogous 'dishwasher' art." This is a weak argument for the '613 patent: Porter is reasonably pertinent to the problem of selecting a durable, clear, thermoformable polymer for a moisture/heat-exposed good, and its express statements about extruded sheet and thermoforming bridge the alleged gap.

7. Dependent-claim mapping

Observation on the dependent claims: several are breadth-limiting in name only — e.g., claim 14 ("three polymer layers") is narrower than claim 1 and is squarely met by Tadros's three-layer stack; claim 18's 500–1200 µm window overlaps Tadros's 125–1250 µm and encompasses its exemplary 700–800 µm. Where a prior-art disclosure overlaps a claimed range, or a claimed range is within the prior art's range, the range is prima facie obvious absent criticality (In re Wertheim, In re Woodruff), and the '613 specification does not establish that any endpoint is critical.

8. Rebuttal of likely secondary considerations

9. Explicit uncertainty / where Align can still win

1. "Effective filling date" dispute (unverified). If Align effectively argues the '613 claims are entitled to 2012-05-14, the art above still predates it — so the analysis does not change. If a claim were held unsupported by 2012, more art (including the parent '691) becomes available. I flag that I did not independently verify written-description support for every claim — this is a genuine open issue.
2. The critical "elastic vs. flexural modulus" equivalence. Several limitations rest on the petitioner's expert view that tensile modulus ≈ flexural modulus for polymers under typical use. If the Board rejects that equivalence, the claim-1 hard-layer "flexural modulus > 150,000 psi" and claim-7 soft-layer "flexural modulus > 35,000 psi" limitations become harder to meet from datasheets. (Note Tritan expressly reports flexural modulus 225,000 psi, which blunts this for the hard layer; Texin reports flexural modulus 6,000 psi, which cannot satisfy claim 7's >35,000-psi alternative — but claim 7 is satisfied by the UTS/compression-set alternatives.)
3. Teaching away (Kalili). Kalili criticizes appliances with higher modulus on the inner (tooth-contacting) layer as causing unwanted localized pressure. That teaching is directed at the innermost layer, not at a hard core between soft layers; it therefore does not teach away from Tadros's soft–hard–soft design. But Align will press it, and its success depends on how the Board scopes Kalili's criticism.
4. "Consisting of" vs. "comprising." The strongest Align argument in the sibling files (that Tadros discloses blends, not a layer "consisting of" a copolyester) is much weaker against the '613 claims, which use "comprising."
5. Procedural status. As of this writing (April 26, 2026), no final written decision exists in IPR2025-00818. Institution was granted 2025-11-06; the Director Review denial was 2026-03-03; Patent Owner's Response was filed 2026-02-20; the projected FWD is ~2026-11-08. Any conclusion here is prospective. Confidence in the individual reference disclosures is high; confidence in the outcome is necessarily lower.
6. Unverified: I did not independently retrieve the DeSimone (US 2006/0078841) full text, the Schrenk exhibit, or the Wen paragraph cites for the sub-layer teaching; I relied on the IPR record's characterization of them. Treat those specific mappings as record-sourced but not independently re-derived.

10. Bottom line

On this record, claims 1–22 of U.S. 10,973,613 B2 are vulnerable to § 103(a) obviousness over at least three overlapping combinations:

• Ground 1 — Tadros + Kalili + Texin 990R (claims 1–2, 4, 6–10, 12–18, 20–22): Tadros supplies the multilayer thermoforming method and soft–hard–soft architecture and a hard co-polyester layer exceeding 150,000 psi; Kalili supplies both the soft-TPU layer concept and the express identification of TEXIN 990R; the Texin 990R sheet supplies 450% elongation and 90A hardness. Motivation: same field, same problem, and Kalili's explicit praise of Texin 990R as a compliant, durable aligner lining.
• Ground 2 — Ground 1 + Wen (claims 3, 5, 11, 19): Wen teaches that splitting a thick layer into thinner sub-layers improves conformity and interlayer adhesion — a straightforward, high-confidence modification.
• Ground 3 — Kalili + Porter + Wen + Texin 990R (claims 1–12, 15, 18–22): an independent path in which Porter supplies the Tritan co-polyester (flexural modulus 225,000 psi, plus the full claim-6 property suite) and an express BPA/ESC-avoidance motivation to replace Kalili's polycarbonate, with Wen supplying the 3+ layer structure.

The claims' patentability hinges almost entirely on numerical property windows that the prior art's commercial datasheets already disclose — a textbook KSR/design-choice/result-effective-variable posture, aggravated by open "comprising" language and a claim 1 that is broader than the specification's only embodiment. Align's best remaining defenses are (i) an adverse ruling on the tensile/flexural modulus equivalence, (ii) a successful teaching-away theory built on Kalili's critique of higher-modulus inner layers, and (iii) objective indicia with a genuine nexus to the recited property windows rather than to multilayer aligners generally — which the currently-available record does not clearly establish.