US 11718565

US Patent 11718565 relates to a panel for forming a floor covering and such floor covering.

Here's a summary of the patent:

• Title: Panel for forming a floor covering and such floor covering
• Assignee: Champion Link International Corp
• Inventors: Thomas Luc Martine Baert, Tom Van Poyer, Sven BOON
• Filing Date: June 4, 2021
• Issue Date: August 8, 2023
• Abstract: The invention relates to a panel, in particular a floor panel, suitable for forming a floor covering, wherein the panel has a substantially planar top side, and a substantially planar bottom side, at least four substantially linear side edges comprising at least one pair of opposite side edges, preferably provided with locking means.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: This claim describes a panel (like a floor or wall panel) for creating a floor or wall covering. The panel has a flat top, a flat bottom, and at least four straight sides. The key feature is that at least one core layer within this panel is made of a magnesium oxide composition. This composition contains magnesium oxide and a magnesium salt, and importantly, it has a magnesium crystal structure that is at least 50% by weight composed of a "whisker-phase" magnesium crystal structure.

• Independent Claim 13: This claim describes a method for making a panel (again, a floor or wall panel). The method involves three main steps:

  1. Preparing a magnesium oxide composition that includes magnesium oxide and at least one magnesium salt.
  2. Adding a slurry (a thin, semi-liquid mixture) that contains at least one compound with at least two hydroxyl groups to the magnesium oxide composition.
  3. Applying a force of at least 7 MPa (megapascals) at a temperature between 45 to 55 degrees Celsius for a specific period of time to form a core layer.

• Independent Claim 14: This claim outlines another method for producing a panel. It's a more detailed version of the previous method claim:

  1. Providing a composition with at least one magnesium oxide.
  2. Providing a brine (saltwater solution) that contains at least one magnesium salt and water.
  3. Mixing the brine into the magnesium oxide composition to create a "magnesium oxide damp composition."
  4. Preferably, adding an aqueous slurry containing at least one compound with at least two hydroxyl groups to this damp composition.
  5. Subjecting the damp composition to at least one screening step (like sifting).
  6. Applying a layer of this screened damp composition onto a mold.
  7. Subjecting this layer to a force with a pressure of at least 7 MPa at a temperature between 45 to 55 degrees Celsius for at least 1 hour, which results in a core layer with an upper and lower surface.

No results for US patent 11718565 were found in the CAFC 2026 dockets.

As of April 26, 2026, I have not found any known litigation involving US patent 11718565 in the provided search results. The search results discuss general patent challenges and court decisions but do not mention any specific cases related to US11718565.

Proceedings overview

As of the current date, July 13, 2026, there are no AIA trial proceedings (Inter Partes Review, Post-Grant Review, or Covered Business Method review) on file for US Patent 11718565. The USPTO Open Data Portal API indicates no such proceedings, and web searches did not surface any additional information regarding PTAB challenges.

Strategic summary

Currently, all claims of US11718565 remain untested by AIA trial proceedings at the PTAB. This means there are no claims that have been canceled or sustained through IPR, PGR, or CBM. For a defendant facing assertion of this patent, the full scope of the patent's claims would still be considered viable from a PTAB challenge perspective.

The absence of PTAB activity implies that the patent has not yet been subject to the scrutiny of an AIA trial, which can be a common occurrence for well-asserted patents. Without any prior PTAB challenges, there are no estoppel limitations under 35 U.S.C. § 315(e)(2) for potential petitioners. Therefore, all available prior-art grounds that meet the statutory requirements for IPR (patents and printed publications under §§ 102 and 103) or PGR (any ground of invalidity under §§ 102, 103, or 112, except best mode) would still be available for a defendant to raise in a new petition, provided the statutory timing requirements are met.

Recommended next steps

Since no PTAB activity exists for US11718565, a defendant currently facing assertion of this patent should consider the following:

• Conduct a thorough prior art search: A comprehensive search for prior art, including patents and printed publications, is crucial to identify potential grounds for invalidity under 35 U.S.C. §§ 102 and 103.
• Evaluate potential for IPR or PGR: If strong prior art is found, assess the feasibility and strategic value of filing an Inter Partes Review (IPR) or Post-Grant Review (PGR) petition against US11718565. The deadline for filing a PGR is typically nine months from the patent's issue date, which was August 8, 2023. Therefore, the PGR window has likely closed. However, IPR petitions can be filed at any time after the later of nine months after the grant of the patent or the termination of any PGR, as long as a district court complaint has not been served for more than one year.
• Monitor for future PTAB filings: Continuously monitor the USPTO's PTAB E2E system and public dockets for any newly filed IPR, PGR, or CBM petitions related to US11718565. This will provide early warning of any challenges to the patent's validity.
• Consult with experienced PTAB counsel: Engage with legal counsel specializing in AIA trial proceedings to strategize the best course of action, including analyzing prior art, drafting petitions, and navigating the complex PTAB process.

Inventors

• Thomas Luc Martine Baert
• Tom Van Poyer
• Sven BOON

The patent does not explicitly state the employers of the inventors at the time of filing. However, the original assignee, Champion Link International Corp, is listed as the applicant.

Original assignee

Champion Link International Corp is the original assignee on the issued patent. The patent itself does not provide information about whether Champion Link International Corp ships a product embodying the claims, its primary line of business, or its current status.

Assignment timeline

There are no assignment records for US11718565 found in the USPTO Assignment Center. This indicates that Champion Link International Corp, the original assignee, still holds ownership of the patent.

Based on publicly available information, it appears that "Champion International Corp" was a major paper and wood products producer that was acquired by International Paper in 2000. However, the assignee for US11718565 is "Champion Link International Corp", which suggests it may be a different entity. Without further information, it's unclear if "Champion Link International Corp" is an operating company, its primary line of business, or its current status.

Timeline diagram

timeline
    title Ownership of US 11718565
    2021 : Filed by Champion Link International Corp
    2023 : Issued to Champion Link International Corp

NPE / troll-pattern signals

1. Shell-entity transfer — unclear. There are no recorded transfers, so it's not possible to determine if it moved to a shell entity. It is not clear if "Champion Link International Corp" itself is a shell entity without more information about its operations.
2. Known asserter in the chain — not present. The patent is currently assigned to the original assignee, Champion Link International Corp, which is not identified as a known asserter on public NPE lists.
3. Repeat correspondent across the chain — not present. With no recorded assignments, there is no chain to observe for repeat correspondents.
4. Cascading transfers — not present. No assignments are recorded.
5. Pre-litigation transfer — not present. No litigation has been identified, and no transfers are recorded.
6. Bankruptcy fire-sale — not present. There is no indication of bankruptcy for Champion Link International Corp. While "Champion International Corp" (a different entity) was acquired in 2000, this patent was filed much later in 2021.
7. Privateering — unclear. No transfers are recorded, and no information suggests privateering activity.
8. Defensive aggregator (anti-NPE) — not present. The patent is currently held by the original assignee, not a defensive aggregator.

Verdict

Insufficient data The absence of recorded assignments makes it impossible to determine if the patent is involved in an NPE pattern. The patent remains with the original assignee, Champion Link International Corp, but without further information about this entity's business activities, a definitive classification cannot be made. No records for US11718565 were found in the USPTO Assignment Center.

Most Relevant Prior Art for US Patent 11718565

To identify the most relevant prior art for US patent 11718565, we need to examine the patent citations listed within the document itself. The patent lists "Prior art keywords" such as "magnesium", "crystal structure", "panel according", "panel", and "phase" which broadly indicate areas of relevance. The detailed description further elaborates on magnesium oxychloride and oxysulfate cements and their crystalline phases, particularly the "whisker-phase" (5-phase) and "flaky" (3-phase) structures.

Here's an analysis of relevant prior art, focusing on these key aspects as described in the patent. Note that the provided search results did not directly list the "cited patents" section of US11718565. Therefore, the analysis will be based on the descriptive text within US11718565 that refers to existing art and general knowledge about magnesium oxide compositions.

The patent itself describes the current state of the art and the problems it aims to solve. Specifically, it notes that:

• The flooring industry commonly uses traditional materials like high-density fiberboard (HDF) and polyvinyl chloride (PVC) for floor tiles.
• Mineral materials are an alternative due to their high dimensional stability, heat resistance, and lower environmental impact, but existing mineral materials (especially those developed as gypsum/drywall replacements) are not suitable for floor panels due lacking sufficient bending strength, impact resistance, indentation resistance, internal cohesion, and surface adhesion.
• Conventional magnesium oxide-based core layers generally consist of more than 50%, and often more than 90%, of irregular, 3-phase crystals, which lead to efflorescence, inferior cohesion, and low surface adhesion, making them unsuitable for flooring panels.
• Increasing the ratio of 5-phase whisker crystals to up to 20% or even 30% is known through costly steam curing processes, but a content of 50% or more, or a ratio of 5-phase to 3-phase greater than 1, is considered unknown in the prior art.

Given these statements from the patent, the most relevant prior art would be any disclosures pertaining to:

1. Magnesium oxide compositions for panels/building materials: This would include compositions of magnesium oxide and magnesium salts (like magnesium sulfate or magnesium chloride) used in construction.
2. Formation of magnesium oxychloride or oxysulfate cements: Specifically, documents discussing the different crystalline phases (5-phase whisker, 3-phase flaky) and their properties.
3. Methods for producing such panels: Especially those involving curing, pressure, and additives to influence crystal structure.

Without a direct list of cited patents from US11718565, it's difficult to provide specific full citations, publication/filing dates, and claim anticipation for each. However, based on the patent's own description of the prior art, the most relevant aspects of existing knowledge would revolve around:

• Magnesium oxysulfate (MOS) and magnesium oxychloride (MOC) cements in general: The patent explicitly mentions "Magnesium oxysulfate cement" and "magnesium (oxy)chloride cement" and their known 5-phase (whisker-like) and 3-phase (flaky or irregular) crystal structures, along with their associated mechanical properties (e.g., bending strength for 5-phase, weaker composition for 3-phase). These general compositions and their phases are considered known in the art.
  • Potential Anticipation: These compositions would form the background for the core layer described in Claim 1. However, the specific ratio of 5-phase whiskers (at least 50% by weight, or a ratio of 5-phase to 3-phase greater than 1) is what the current invention distinguishes itself by. Therefore, general MOS/MOC cement compositions themselves would likely anticipate the basic composition but not the advantageous crystal structure ratio of Claim 1. Claims 13 and 14, regarding the method of achieving this ratio, would also build upon the known methods of preparing these cements.
• Reactive magnesia production: The patent notes that "Magnesium oxysulfate and oxychloride whiskers can be produced via mixing of reactive magnesia with an aqueous magnesium sulfate or chloride solution," and describes the calcination process for reactive magnesia. The existence and production of reactive magnesia are therefore part of the general prior art.
  • Potential Anticipation: The use of reactive magnesia as a raw material for magnesium oxide compositions would be generally anticipated for claims involving the preparation of the core layer (e.g., claims 13 and 14).
• Traditional methods of producing magnesium oxide core boards: The patent details how these involve "mixing of an aqueous solution of brine containing a magnesium salt with said reactive magnesium oxide solution to form a mixture in the form of a (liquid) slurry, which is then poured in a mold and allowed to set or cure typically over the course of one to 28 days." It critically points out that these methods lead to density gradients and porous structures, inhibiting whisker growth.
  • Potential Anticipation: The general steps of mixing magnesium oxide, magnesium salt, and water, and allowing it to cure, as outlined in claims 13 and 14, would be anticipated by these traditional methods. However, the specific additions of hydroxyl-group compounds and the application of elevated temperature and pressure, which the current patent claims as novel to achieve a high whisker-phase ratio, would differentiate the invention from this prior art.

To perform a thorough analysis of specific prior art citations, one would need to access the "References Cited" section of US11718565 from an official USPTO document or database. Without this specific list, a detailed analysis of each cited patent's description and its direct anticipation of claims under 35 U.S.C. § 102 cannot be provided.

Based on the general technical disclosures within the patent and common knowledge of related fields:

• The fundamental chemistry of magnesium oxide and its reactions with magnesium salts to form cements, including the existence of different crystal phases (like 5-phase and 3-phase), is widely understood in material science and chemistry.
• Methods for preparing magnesium oxide from magnesite by calcining to obtain caustic-burned magnesia powder and then leaching and reacting with solutions to obtain magnesium hydroxide precipitate which is then calcined to magnesium oxide are also known.
• Magnesium oxide itself is a well-known chemical compound used in various applications, including as a component in Portland cement and Sorel cement.
• The general concept of using additives to influence material properties is common in cement and composite material industries. For example, citric acid is mentioned in a patent for rapidly dissolving tablets, and magnesium oxide particle aggregates and their production methods are also known.

To precisely determine which claims (or parts thereof) are potentially anticipated by specific prior art, access to the cited references would be critical.

Obviousness Analysis of US Patent 11718565 Under 35 U.S.C. § 103

This analysis of US Patent 11718565 focuses on the obviousness of its claims, considering combinations of prior art references (categorized as general technical knowledge and methods described within the patent itself) that would render the invention obvious to a person having ordinary skill in the art (POSA). The motivation for combining these references is also explored.

The patent identifies a primary problem: traditional magnesium oxide-based floor panels suffer from weak compositions, efflorescence, and poor cohesion due to a predominance of flaky or irregular 3-phase crystals. It states that achieving a core layer with at least 50% by weight of whisker-phase (5-phase) magnesium crystal structure, or a 5-phase to 3-phase ratio greater than 1, was "unknown" in the prior art [cite: US11718565 Description]. However, the patent also explicitly outlines the known advantages of the 5-phase whiskers for improved mechanical properties, thereby establishing a clear motivation for a POSA to seek to maximize this phase.

For this analysis, we will consider the following categories of prior art, as described within US11718565:

• P1 (General knowledge of MOS/MOC cements): This includes the understanding that magnesium oxide (MgO) combined with magnesium salts (e.g., MgSO4 or MgCl2) forms magnesium oxysulfate (MOS) or oxychloride (MOC) cements, which can exhibit different crystalline phases. Specifically, it was known that a 5-phase crystal structure forms beneficial needle- or whisker-like crystals with good bending strength, impact resistance, indentation resistance, and water resistance, while a 3-phase crystal structure forms flaky or irregular crystals resulting in weaker compositions and efflorescence [cite: US11718565 Description]. A POSA would also know that conventional methods typically yield a low proportion of the desirable 5-phase, often less than 20-30%, with the majority being the 3-phase [cite: US11718565 Description]. The superior properties of the 5-phase whiskers make them highly desirable for durable flooring applications [cite: US11718565 Description].

• P2 (Traditional Methods for Magnesium Oxide Core Boards): This covers known processes involving mixing reactive magnesia with an aqueous magnesium salt solution (brine) to form a liquid slurry, which is then poured into a mold and cured. These methods were understood to result in density gradients, air bubbles, and porous structures due to excessive water content [cite: US11718565 Description].

• P3 (General Chemical/Materials Engineering Principles): This encompasses widely known techniques in material science and chemistry, such as:

  • Using chemical additives (e.g., acids, compounds with hydroxyl groups) to influence crystal morphology, act as nucleating agents, or modify reaction pathways in cementitious systems [cite: US11718565 Description]. The patent specifically mentions phosphoric acid and citric acid as examples of such additives.
  • Applying elevated temperatures to accelerate chemical reactions, facilitate molecular exchanges, or control crystal phase formation [cite: US11718565 Description]. The patent mentions that steam curing (above 100°C) was known to increase 5-phase content to 20-30% [cite: US11718565 Description].
  • Applying pressure during curing to increase material density, reduce porosity, and promote crystal intergrowth in composite materials or cements [cite: US11718565 Description].
  • Controlling reactant ratios (e.g., water content, molar ratios of components) to influence the final product and crystal phases formed [cite: US11718565 Description].
  • Using screening or sieving to achieve a more homogeneous composition [cite: US11718565 Description].

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Analysis of Independent Claim 1 (Product Claim)

Claim 1: A panel... comprising at least one core layer... comprising a magnesium oxide composition... comprising at least a magnesium oxide and a magnesium salt, wherein said magnesium oxide composition comprises a magnesium crystal structure which comprises at least 50% by weight of at least one whisker-phase magnesium crystal structure.

Obviousness Argument (P1 + P3):
A POSA, armed with the knowledge from P1, would understand that 5-phase whisker crystals impart superior mechanical and water-resistant properties highly desirable for floor panels. The problem, as recognized in P1, is that traditional methods yield a low percentage of these beneficial whiskers, with the majority being the weaker 3-phase [cite: US11718565 Description].

Motivated by the clear desire to improve the bending strength, impact resistance, indentation resistance, internal cohesion, and surface adhesion of magnesium oxide-based panels for flooring, a POSA would seek to maximize the proportion of the 5-phase whisker structure [cite: US11718565 Description]. Given the general chemical and materials engineering principles in P3, a POSA would routinely investigate various methods to influence crystal growth and phase formation in cementitious systems. This would include experimenting with:

• Additives: Introducing known chemical additives (like acids or compounds with hydroxyl groups, as generically known to influence crystallization) into the magnesium oxide mixture to promote the formation of the desired whisker phase. The patent itself theorizes that hydroxyl groups act as "seeds" or displace water molecules to favor whisker growth [cite: US11718565 Description].
• Process Conditions: Modifying curing conditions such as temperature (knowing from P3 that elevated temperatures, even steam curing, could increase 5-phase content) and pressure (knowing from P3 that pressure improves density and crystal intergrowth).

While the patent claims the specific ratio of >50% whisker-phase was unknown, a POSA would have a strong motivation and reasonable expectation of success (based on known scientific principles and existing, albeit less effective, methods like steam curing mentioned in P1) to explore and optimize these parameters to enhance the formation of the known-beneficial 5-phase whiskers. Arriving at a composition where the desired whisker phase predominates would be an obvious endeavor, even if the exact optimal parameters required some routine experimentation.

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Analysis of Independent Claim 13 (Method Claim)

Claim 13: A method for producing a panel, comprising: a) preparing a magnesium oxide composition comprising magnesium oxide and at least one magnesium salt; b) adding at least one slurry comprising at least one compound comprising at least two hydroxyl groups to the magnesium oxide composition; and c) applying a force of at least 7 MPa at a temperature in the range of 45 to 55 degrees Celsius for a predetermined period of time to form a core layer.

Obviousness Argument (P1 + P2 + P3):
Starting with the traditional methods (P2) for producing magnesium oxide core boards (steps similar to "preparing a magnesium oxide composition comprising magnesium oxide and at least one magnesium salt"), a POSA would be motivated by the deficiencies of these traditional boards (weakness, efflorescence, porosity) and the known advantages of the 5-phase whisker structure (P1) to modify the process to produce a superior product.

A POSA would turn to general materials engineering principles (P3) to achieve this goal:

• b) Adding at least one slurry comprising at least one compound comprising at least two hydroxyl groups: Recognizing that additives can influence crystal growth (P3), and knowing that specific compounds (like acids with hydroxyl groups, such as phosphoric acid or citric acid mentioned in the patent) are known to affect crystallization in various chemical systems, a POSA would be motivated to introduce such an additive into the magnesium oxide composition. The patent itself notes that these additives "augment" the whisker-phase ratio [cite: US11718565 Description]. The theoretical mechanism (hydroxyl groups replacing water, acting as "seeds") described in the patent, even if novel in detail, would be explored by a POSA experimenting with crystallization modifiers.
• c) Applying a force of at least 7 MPa at a temperature in the range of 45 to 55 degrees Celsius for a predetermined period of time:
  • Applying Pressure (at least 7 MPa): A POSA knows that applying pressure during curing (P3) is a standard technique to increase density, reduce porosity, and promote crystal intergrowth in cementitious materials. Given the problems of porosity and low density in traditional boards (P2), and the desire for a denser, stronger core layer for flooring, applying pressure would be an obvious modification. The specific pressure of "at least 7 MPa" would be within the range a POSA would routinely experiment with to achieve desired densification.
  • Elevated Temperature (45-55°C): A POSA is aware that temperature influences chemical reactions and crystal phase formation (P3). Knowing that even higher temperatures (steam curing >100°C) could increase 5-phase content (P1), a POSA would logically experiment with elevated temperatures, including moderate ranges like 45-55°C, to optimize crystal growth and potentially reduce curing time or energy costs compared to steam curing. The patent's finding that this range, particularly with the additive, reduces flaky crystals below 50% [cite: US11718565 Description], while presented as a successful outcome, falls within the scope of routine experimentation for a POSA seeking to shift crystal morphology.

The combination of these known techniques (additives, pressure, and moderate heat) to improve the characteristics of magnesium oxide cement, motivated by the recognized deficiencies of prior art panels and the known benefits of 5-phase crystals, would be obvious to a POSA.

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Analysis of Independent Claim 14 (Detailed Method Claim)

Claim 14: A method for producing a panel, comprising: a1) providing a composition comprising at least one magnesium oxide; b1) providing a brine comprising at least one magnesium salt and water; c1) mixing of said brine into said composition of magnesium oxide such that a magnesium oxide damp composition is formed; d1) preferably adding at least one aqueous slurry comprising at least one compound comprising at least two hydroxyl groups to the magnesium oxide composition; e1) subjecting the magnesium oxide damp composition to at least one screening step f1) applying at least one layer of the magnesium oxide composition upon a mold; and g1) subjecting the layer of magnesium oxide damp composition to a force having a pressure of at least 7 MPa at a temperature at least in the range of 45 to 55 degrees Celsius for at least 1 hour such that a core layer comprising an upper core surface and a lower core surface is obtained.

Obviousness Argument (P1 + P2 + P3):
Claim 14 elaborates on the method steps, but the core inventive concepts remain consistent with Claim 13.

• Steps a1, b1, c1, f1: These steps (providing MgO, brine, mixing to form a damp composition, and applying it to a mold) are directly anticipated by or are obvious variations of traditional methods for producing magnesium oxide core boards (P2). The specific characteristic of forming a "magnesium oxide damp composition" with a relatively low moisture content (e.g., below 25 wt%, preferably around 7 wt% [cite: US11718565 Description]) instead of a liquid slurry would be an obvious modification for a POSA attempting to reduce porosity and density gradients inherent in traditional, high-water content slurries (P2), especially when combined with pressing.
• d1) Preferably adding at least one aqueous slurry comprising at least one compound comprising at least two hydroxyl groups: This step is identical in concept to step (b) of Claim 13, and the obviousness argument remains the same: a POSA would be motivated by P1 to improve properties and would use known additives (P3) to influence crystallization.
• e1) Subjecting the magnesium oxide damp composition to at least one screening step: A POSA knows that screening or sieving (P3) is a conventional method to achieve a more homogeneous, even, and consistent composition. Given the goal of producing a high-quality, uniform core layer with consistent density (which the patent highlights as a benefit of its method [cite: US11718565 Description]), incorporating a screening step would be an obvious processing improvement.
• g1) Subjecting the layer of magnesium oxide damp composition to a force having a pressure of at least 7 MPa at a temperature at least in the range of 45 to 55 degrees Celsius for at least 1 hour: This step is identical in concept to step (c) of Claim 13, and the obviousness argument remains the same: a POSA would use known pressure and temperature controls (P3) to enhance densification and promote the desirable 5-phase crystal growth, motivated by the known benefits of 5-phase for flooring applications (P1).

The combination of these generally known and motivated process steps, aimed at improving the physical and crystalline properties of magnesium oxide-based panels for flooring, would be obvious to a POSA seeking to address the deficiencies of prior art methods and products. The patent itself provides the strong motivation to create a predominantly whisker-phase structure, and the individual elements of the method are either known (P1, P2) or represent routine application of general engineering principles (P3) to achieve a desired, known beneficial outcome.

US Patent 11718565 was filed on June 4, 2021, and issued on August 8, 2023. [cite: US11718565B2]

Patent Term Adjustments (PTA) and Extensions (PTE):

• Patent Term Adjustment (PTA): PTA is granted to compensate for administrative delays by the USPTO during patent prosecution. It extends the patent's term beyond the standard 20 years from the earliest filing date. The patent record itself, or a detailed USPTO Patent Center search, would typically contain the specific PTA calculation. The provided text for US11718565 states its legal status as "Active, expires 2040-04-08," which is an adjusted expiration date, indicating PTA has been applied [cite: US11718565B2].
• Patent Term Extension (PTE): PTE is distinct from PTA and is awarded to compensate for delays incurred in obtaining regulatory approval for certain patented products, primarily pharmaceuticals, medical devices, and food/color additives. The patent text does not indicate that US11718565 is for a product subject to regulatory review, therefore, it is unlikely to have a PTE.

Continuation and Divisional Applications:
A continuation application is filed to pursue additional claims to an invention disclosed in an earlier, still-pending application (the "parent"), using the same specification and claiming priority from the parent's filing date. A divisional application is filed when the USPTO requires claims to be divided into multiple inventions.

The Google Patents information for US11718565 lists "Other versions: US20210292237A1" and "Priority claimed from US16/778,570" which links to US11053696B1. This suggests a family of related applications. The "Priority to US17/339,168" is itself US11718565. The "Priority to US18/337,904" which links to US12122721B2. This indicates that US11718565 is part of a patent family and claims priority from earlier applications. [cite: US11718565B2]

• Parent Application: US16/778,570 (which resulted in US11053696B1) is a priority application for US11718565 [cite: US11718565B2].
• Published Application: US20210292237A1 is a published application that is an "Other version" of US11718565 [cite: US11718565B2]. This could be a publication of the present application or a related continuation/divisional.
• Child Application: US18/337,904 (which resulted in US12122721B2) is a later-filed application that claims priority to US11718565 [cite: US11718565B2]. This indicates that US18/337,904 is a continuation, divisional, or continuation-in-part of US11718565.

Related Family Members:
Based on the priority data provided in the Google Patents listing for US11718565:

• US11053696B1 (from application US16/778,570) [cite: US11718565B2]
• US20210292237A1 (published application) [cite: US11718565B2]
• US12122721B2 (from application US18/337,904) [cite: US11718565B2]

Projected Expiration Date:
The Google Patents entry for US11718565 states its legal status as "Active, expires 2040-04-08" [cite: US11718565B2]. This "adjusted expiration" date already accounts for any Patent Term Adjustment (PTA) applied to the patent. The standard patent term is 20 years from the earliest filing date (or priority date if applicable). Given the priority date of January 31, 2020 [cite: US11718565B2], a basic 20-year term would put the expiration around January 31, 2040. The listed expiration date of April 8, 2040, suggests that PTA has added a period of approximately 2 months and 8 days to the patent term. [cite: US11718565B2]

Defensive Disclosure: Derivatives of US Patent 11718565

Current Date: July 13, 2026

This Defensive Disclosure document outlines a series of derivative variations and extensions of US Patent 11718565, titled "Panel for forming a floor covering and such floor covering." The objective is to establish prior art for foreseeable incremental advancements by competitors, thereby rendering such advancements obvious or non-novel. This document focuses exclusively on generating new derivative works and technical disclosures, building upon the core inventive concepts of US11718565 without restating its existing claims.

Combination Prior Art Scenarios for US11718565

To establish robust prior art, the principles and methods of US11718565 can be combined with existing open-source standards and widely adopted technical specifications:

1. Integration with OPC UA for Process Control and Monitoring: The manufacturing parameters (e.g., temperature, pressure, additive dosage, reactive magnesia to salt ratio, moisture content, curing duration) detailed in US11718565 for achieving high whisker-phase magnesium crystal structures can be integrated into an industrial control system utilizing the OPC Unified Architecture (OPC UA) standard. This enables secure, reliable, and platform-independent data exchange between manufacturing equipment (mixers, presses, sensors, dosing units) and higher-level Manufacturing Execution Systems (MES) or Supervisory Control and Data Acquisition (SCADA) systems. This combination renders obvious the real-time monitoring, data logging, and automated adjustment of the patented process parameters to maintain optimal whisker formation and panel quality across different production lines and facilities.
2. Standardized Material Characterization with ASTM Standards: The core layer compositions with high whisker-phase magnesium crystal structures (e.g., 5-phase magnesium oxysulfate or oxychloride) described in US11718565 can be subjected to standardized mechanical, physical, and chemical characterization according to ASTM International Standards. For instance, evaluating compressive and flexural strength per ASTM C39/C39M for compressive strength of cylindrical concrete specimens or ASTM C348 for flexural strength of hydraulic-cement mortars, or water absorption per ASTM C20. The disclosure of such testing methodologies applied to the specific whisker-phase predominant magnesium oxycement compositions of US11718565, and their performance relative to the enhanced properties claimed by the patent, renders obvious any future claims related to material property quantification using standard testing protocols.
3. Digital Twin Implementation with Industrial Digital Twin Association (IDTA) Specifications: A comprehensive digital twin of the panel's lifecycle, from raw material sourcing and manufacturing to in-service performance and end-of-life recycling, can be developed following the data models and interface specifications published by the Industrial Digital Twin Association (IDTA) or similar open frameworks. This digital twin would encompass the detailed chemical reactions, crystal growth kinetics, and microstructural evolution of the magnesium oxycement core layer as described in US11718565, along with process parameters. Integrating real-time sensor data (e.g., from embedded IoT sensors monitoring humidity, temperature, and strain) from actual panels, and utilizing predictive analytics within this open digital twin framework, makes obvious the use of such advanced simulation and monitoring for quality assurance, predictive maintenance, and optimized material usage for US11718565-type panels.

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Derivatives of Independent Claim 1: Panel with High Whisker-Phase Core

Independent Claim 1: A panel... comprising at least one core layer... comprising a magnesium oxide composition... comprising at least a magnesium salt, wherein said magnesium oxide composition comprises a magnesium crystal structure which comprises at least 50% by weight of at least one whisker-phase magnesium crystal structure.

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Derivative 1.1: Ceramic Whisker-Reinforced Geopolymer Panel

Enabling Description:
A panel for forming a floor or wall covering, comprising a core layer made from a geopolymer matrix reinforced with silicon carbide (SiC) whiskers. The geopolymer is formed from an alkali-activated aluminosilicate source (e.g., metakaolin, fly ash, slag) and an alkaline activator (e.g., sodium silicate, potassium hydroxide solution). The SiC whiskers, having an average diameter of 0.1-0.5 micrometers and an average length of 10-100 micrometers, are incorporated at a concentration of at least 50% by weight of the solid reinforcing material within the geopolymer matrix. The resulting core layer exhibits a dense, interlocking microstructure, providing enhanced flexural strength, impact resistance, and chemical stability, analogous to the beneficial properties of the whisker-phase magnesium oxycement described in US11718565. The geopolymerization process occurs at ambient or slightly elevated temperatures (e.g., 20-80°C) and can be accelerated by mild pressing (e.g., 5-10 MPa) during initial curing.

graph TD
    A[Aluminosilicate Source] --> B(Alkaline Activator)
    C[Silicon Carbide Whiskers] --> D{Mixing Chamber}
    B --> D
    A --> D
    D --> E[Geopolymer Slurry]
    E --> F[Mold Application]
    F --> G{Pressing & Curing @ 20-80C, 5-10 MPa}
    G --> H[Whisker-Reinforced Geopolymer Panel Core]

---

Derivative 1.2: Bio-Polymer Composite Panel with Cellulose Nanofiber Whiskers

Enabling Description:
A panel with a core layer composed of a thermoplastic bio-polymer matrix, such as polylactic acid (PLA) or polyhydroxyalkanoates (PHA), reinforced with highly aligned cellulose nanofibers (CNF) functioning as whisker-like structures. The CNF are prepared from lignocellulosic biomass (e.g., wood pulp, agricultural waste) via mechanical fibrillation or chemical treatments (e.g., TEMPO-oxidation). The CNF are incorporated into the bio-polymer matrix at a concentration of at least 15% by weight, forming a continuous, interlocked network with an average diameter of 5-50 nanometers and an average length of 500-2000 nanometers. The composite is processed via hot pressing or extrusion at temperatures suitable for the bio-polymer (e.g., 170-200°C for PLA) and pressures of 10-30 MPa to achieve high densification and orientation of the CNF, yielding a lightweight, high-strength core with improved bending modulus and impact toughness.

graph TD
    A[Lignocellulosic Biomass] --> B(CNF Extraction & Fibrillation)
    C[Thermoplastic Bio-Polymer Pellets] --> D{Melt Compounding}
    B --> D
    D --> E[CNF-Polymer Composite]
    E --> F[Hot Pressing / Extrusion @ 170-200C, 10-30 MPa]
    F --> G[Bio-Polymer Panel Core with Aligned CNF]

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Derivative 1.3: Refractory Panel for High-Temperature Industrial Furnaces

Enabling Description:
A high-temperature refractory panel suitable for lining industrial furnaces, comprising a core layer made from a magnesium aluminate spinel (MgAl2O4) matrix, reinforced with in-situ grown or ex-situ added magnesium oxychloride (MOC) whiskers of the 5-1-8 phase (5Mg(OH)2.MgCl2.8H2O). The MgAl2O4 matrix provides high-temperature stability (up to 1800°C). The MOC whiskers are stabilized at elevated temperatures through precise control of the MgO:MgCl2:H2O molar ratio and curing under specific conditions (e.g., 200-500°C under controlled atmospheric pressure for initial crystallization, followed by sintering at >1000°C). The whisker-phase content constitutes at least 50% by weight of the binder phase, contributing to enhanced thermal shock resistance, hot flexural strength, and reduced spalling. The panel formulation also includes high-purity alumina aggregates to further improve refractory performance.

stateDiagram-V2
    [*] --> Raw_Material_Prep
    Raw_Material_Prep --> Mixing_MOC_Precursors: MgO, MgCl2, H2O
    Raw_Material_Prep --> Mixing_MgAl2O4_Precursors: MgO, Al2O3
    Mixing_MOC_Precursors --> Initial_Curing_MOC: 200-500C, Controlled P
    Mixing_MgAl2O4_Precursors --> Forming_MgAl2O4_Matrix
    Initial_Curing_MOC --> MOC_Whiskers_Formed
    MOC_Whiskers_Formed --> Core_Layer_Compaction: Blending with MgAl2O4 Matrix
    Forming_MgAl2O4_Matrix --> Core_Layer_Compaction
    Core_Layer_Compaction --> Sintering_Process: >1000C
    Sintering_Process --> Refractory_Panel_Core
    Refractory_Panel_Core --> [*]

---

Derivative 1.4: Subsea Structural Panel with Corrosion-Resistant Oxychloride Whiskers

Enabling Description:
A structural panel for subsea applications (e.g., marine pilings, underwater pipeline protection), featuring a core layer composed of a magnesium oxychloride cement (MOC) matrix predominantly consisting of stable 5-phase (5Mg(OH)2.MgCl2.8H2O or 5-1-7 phase) whiskers, making up at least 60% by weight of the crystal structure. The MOC composition is formulated with seawater or high-salinity brine as the water source, containing specific corrosion inhibitors (e.g., phosphates, silicates) encapsulated within the whiskers or matrix to resist chloride-induced degradation in saline environments. The panels are formed under hyperbaric pressure conditions (e.g., 10-50 MPa) at ambient or slightly elevated temperatures (e.g., 20-35°C) to simulate deep-sea environments and promote denser whisker intergrowth, imparting superior compressive strength, erosion resistance, and long-term durability in corrosive marine conditions.

flowchart LR
    A[Reactive Magnesia] -- Mix with --> B(High-Salinity Brine + Corrosion Inhibitors)
    B -- Forms --> C{MOC Damp Composition}
    C -- Molded & Cured Under --> D(Hyperbaric Pressure (10-50 MPa) & Ambient Temp (20-35C))
    D -- Results in --> E[Subsea Panel Core (>=60% 5-Phase MOC Whiskers)]
    E -- Enhanced by --> F(Corrosion Resistance)
    E -- Provides --> G(High Compressive Strength)

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Derivative 1.5: AI-Optimized Panel with Real-time Whisker Growth Control

Enabling Description:
A panel with a core layer comprising a magnesium oxycement (oxysulfate or oxychloride) composition, where the production process is optimized by an Artificial Intelligence (AI) control system for maximizing whisker-phase crystal structure to at least 70% by weight. The AI system integrates real-time data from in-situ sensors (e.g., X-ray diffraction for phase analysis, rheological sensors for damp composition consistency, thermal cameras for temperature distribution within the mold, acoustic sensors for early-stage crack detection) and adjusts critical process parameters dynamically. These parameters include the precise molar ratios of MgO:salt:H2O, additive concentration (e.g., citric acid), and the spatiotemporal profiles of applied pressure (7-20 MPa) and temperature (40-60°C) during the curing phase. The AI employs machine learning models (e.g., reinforcement learning, Gaussian processes) to predict whisker morphology and density, ensuring optimal material properties and minimal flaky phase formation for each panel batch.

sequenceDiagram
    participant S as Sensors (XRD, Rheology, Thermal, Acoustic)
    participant AI as AI Control System (ML Models)
    participant PC as Process Controllers (Mixer, Press, Heater)
    participant M as Magnesium Oxycement Production Line

    S->>AI: Real-time Material & Process Data
    AI->>AI: Analyze Whisker Morphology & Density
    AI->>AI: Predict Optimal Parameters
    AI->>PC: Adjust Molar Ratios, Additive Dose, P/T Profiles
    PC->>M: Execute Parameter Adjustments
    M->>S: (Updated) Real-time Data
    Note over M: Iterative Optimization of Whisker Growth (>=70% whisker-phase)

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Derivative 1.6: Biodegradable Magnesium Oxysulfate Panel with Controlled Disintegration

Enabling Description:
A floor panel designed for temporary installations or situations requiring controlled disintegration for easy recycling or environmental remediation. The core layer comprises a magnesium oxysulfate cement composition with a whisker-phase (5-phase) crystal structure constituting at least 50% by weight, providing initial structural integrity. However, the matrix incorporates a precisely dosed biodegradable polymer (e.g., polyvinyl alcohol, starch-based polymer) or a pH-sensitive additive (e.g., calcium carbonate microspheres) that degrades or dissolves under specific environmental triggers (e.g., prolonged exposure to elevated humidity, slightly acidic conditions, or microbial activity). This degradation gradually weakens the inter-whisker bonding and the overall matrix cohesion, leading to controlled panel disintegration into inert mineral components. The production method involves co-mixing the biodegradable additive with the magnesium oxide and magnesium sulfate precursors, followed by curing at 45-55°C under 7-10 MPa pressure to initially form the robust whisker structure while preserving the integrity of the biodegradable component.

stateDiagram-V2
    [*] --> Initial_State: Panel in use
    Initial_State --> Exposure_to_Trigger: Elevated Humidity / Acidic Conditions / Microbial Activity
    Exposure_to_Trigger --> Polymer_Degradation: Biodegradable polymer starts breaking down
    Exposure_to_Trigger --> Additive_Dissolution: pH-sensitive additive dissolves
    Polymer_Degradation --> Weakening_Matrix: Reduced inter-whisker bonding
    Additive_Dissolution --> Weakening_Matrix
    Weakening_Matrix --> Controlled_Disintegration: Panel breaks down
    Controlled_Disintegration --> End_of_Life: Inert mineral components
    End_of_Life --> [*]

---

Derivatives of Independent Claim 13: Method for Producing Panels with High Whisker-Phase Core

Independent Claim 13: A method for producing a panel, comprising: a) preparing a magnesium oxide composition comprising magnesium oxide and at least one magnesium salt; b) adding at least one slurry comprising at least one compound comprising at least two hydroxyl groups to the magnesium oxide composition; and c) applying a force of at least 7 MPa at a temperature in the range of 45 to 55 degrees Celsius for a predetermined period of time to form a core layer.

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Derivative 13.1: Supercritical Fluid-Assisted Mixing and Dosing Method

Enabling Description:
A method for producing a panel core layer with enhanced whisker-phase magnesium crystal structure, characterized by utilizing supercritical carbon dioxide (scCO2) as a solvent and dispersant during mixing. Step (a) involves preparing the magnesium oxide composition (reactive magnesia and magnesium salt) under elevated pressure. Step (b) introduces the slurry containing the compound with at least two hydroxyl groups (e.g., citric acid solution) into the scCO2-saturated magnesium oxide composition. The scCO2 acts as a transient carrier and provides superior penetration and homogenization of the hydroxyl additive and water throughout the mixture, leading to more uniform nucleation sites for whisker growth. After mixing, the scCO2 is depressurized, leaving a highly uniform damp composition. Step (c) then proceeds with applying a force of at least 7 MPa at 45-55°C for curing, resulting in a core layer with a higher density and an even greater percentage of whisker-phase crystals due to the superior initial mixing.

flowchart TD
    A[Reactive Magnesia + Magnesium Salt] -- Pressurized with --> B(Supercritical CO2 Chamber)
    C[Hydroxyl-Compound Slurry] --> B
    B --> D{Supercritical Mixing & Dispersion}
    D -- Depressurize CO2 --> E[Homogeneous Magnesium Oxide Damp Composition]
    E -- Apply Force (>=7 MPa) & Temp (45-55C) --> F[Core Layer with Enhanced Whisker Phase]

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Derivative 13.2: Continuous High-Throughput Extrusion Method

Enabling Description:
A continuous manufacturing method for panels, where the core layer is formed via an extrusion process. Step (a) involves continuous gravimetric feeding and mixing of reactive magnesium oxide powder and a magnesium salt (e.g., MgSO4 or MgCl2). Step (b) integrates an inline, high-shear mixer to continuously add and homogenize an aqueous slurry comprising at least one hydroxyl group compound (e.g., oxalic acid) into the flowing dry composition, forming a low-moisture damp extrudable material. This damp composition is then fed into a twin-screw extruder. Step (c) is performed within the extruder barrel and subsequent continuous press, where the material is subjected to a continuous application of force (e.g., 8-15 MPa) and controlled heating (e.g., 48-52°C) as it is shaped and partially cured into a continuous sheet or panel profile. The extruded sheet is then cut to size and allowed to fully cure. This process significantly reduces batch times and allows for efficient, high-volume production of panels with predominantly whisker-phase core layers.

graph LR
    A[Reactive MgO Feed] --> M(Continuous Mixer)
    B[Magnesium Salt Feed] --> M
    C[Hydroxyl Slurry Feed] --> M
    M --> E[Twin-Screw Extruder]
    E -- Apply P (8-15 MPa) & T (48-52C) --> F[Continuous Press Section]
    F --> G[Continuous Panel Core Sheet]
    G --> H[Cutting & Final Curing]

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Derivative 13.3: Dynamic Pressure and Temperature Profile Curing

Enabling Description:
A method for producing a panel with an optimized whisker-phase crystal structure by employing a dynamic, multi-stage pressure and temperature curing profile. Step (a) and (b) are performed as described in the parent patent. For step (c), the magnesium oxide damp composition in the mold is subjected to a programmed sequence of varying pressures and temperatures. For example, an initial compaction phase at 10 MPa for 30 minutes at 40°C, followed by a whisker growth phase at 7 MPa for 4 hours at 55°C, and concluding with a densification phase at 15 MPa for 2 hours at 50°C. This dynamic profile is designed to first compact the material, then optimize conditions for whisker nucleation and growth, and finally consolidate the structure, preventing pore formation and promoting maximal whisker interlocking. The specific pressure and temperature ramps and dwells are determined experimentally to achieve a core layer with a precisely engineered whisker-to-flake ratio, potentially exceeding 90% whisker phase, and enhanced mechanical properties.

stateDiagram-V2
    [*] --> Damp_Composition_Prepared
    Damp_Composition_Prepared --> Compaction_Phase: 10 MPa, 40C, 30 min
    Compaction_Phase --> Whisker_Growth_Phase: 7 MPa, 55C, 4 hrs
    Whisker_Growth_Phase --> Densification_Phase: 15 MPa, 50C, 2 hrs
    Densification_Phase --> Core_Layer_Formed
    Core_Layer_Formed --> [*]

---

Derivative 13.4: In-Situ Soil Stabilization Method

Enabling Description:
A method for in-situ stabilization of soil or sub-base layers for construction projects, effectively creating a high-strength, water-resistant base. This involves adapting the principles of forming a whisker-phase magnesium oxycement core. Step (a) comprises preparing a magnesium oxide dry composition (reactive magnesia and magnesium sulfate/chloride) and homogeneously distributing it into a prepared soil layer. Step (b) involves injecting a controlled aqueous slurry comprising at least one compound with at least two hydroxyl groups (e.g., phosphoric acid) directly into the treated soil layer, ensuring thorough saturation and mixing. Step (c) applies a continuous or pulsed ground compaction force (e.g., via vibratory rollers or dynamic compaction equipment achieving localized pressures of at least 7 MPa) while simultaneously inducing exothermic reactions or applying localized heating (e.g., via microwave emitters or geothermal heat exchange) to maintain temperatures within the 45-55°C range for a predetermined period. This process transforms the soil into a robust, high-bearing-capacity layer reinforced by the in-situ formation of interlocking magnesium oxycement whiskers.

flowchart TD
    A[Soil Preparation] --> B(Distribute MgO Dry Composition)
    C[Hydroxyl Slurry (Aqueous)] --> D(Inject & Mix In-Situ)
    D --> E{Compaction & Heating (45-55C, >=7 MPa)}
    E --> F[Stabilized Soil Layer with Whisker-Phase Cement]

---

Derivative 13.5: AI-Driven Multi-Variate Process Control for Whisker Optimization

Enabling Description:
A method utilizing an Artificial Intelligence (AI) system for real-time, multi-variate process control to dynamically optimize the whisker-phase crystal structure formation in magnesium oxycement panels. Steps (a) and (b) are executed with automated dosing systems. Step (c) involves applying pressure and temperature, but these parameters, along with the precise ratio of MgO to magnesium salt and the concentration of the hydroxyl compound, are continuously monitored and adjusted by the AI. The AI system uses predictive models trained on extensive datasets of material input parameters, curing conditions, and resulting whisker-phase percentages (quantified by techniques like Rietveld refinement of XRD data). The AI anticipates deviations from optimal whisker growth based on real-time sensor feedback (e.g., pH of mixture, exothermic reaction rate, material impedance) and issues immediate commands to pneumatic presses, heating elements, and additive pumps to maintain the optimal 5-phase formation kinetics and morphology throughout the predetermined curing period.

graph LR
    A[Raw Material Influx (MgO, Salt, H2O, Additive)] --> B{Automated Dosing System}
    B --> C(Mixing Vessel)
    C --> D[Mold Application]
    D --> E{Curing Chamber (Pressure & Temp)}
    E -- Real-time Sensor Data --> AI[AI Control & Optimization Unit]
    AI -- Control Signals --> B
    AI -- Control Signals --> E
    E --> F[Core Layer (Optimized Whisker Phase)]

---

Derivative 13.6: Failure-Mode Engineered Panel Production Method

Enabling Description:
A method for producing magnesium oxycement panels specifically engineered for controlled, predictable failure or easy disassembly, rather than maximum strength. Step (a) involves preparing the magnesium oxide composition. Step (b) incorporates a high concentration of crystal growth inhibitors (e.g., high-alkalinity compounds, specific organic retarders) into the hydroxyl slurry, or conversely, a reduced concentration of the hydroxyl compound, specifically chosen to promote the formation of the weaker 3-phase (flaky/irregular) crystal structure over the whisker-phase. Additionally, sacrificial fillers (e.g., microencapsulated pH-responsive polymers that expand upon trigger, low-melting-point waxes) are introduced. Step (c) applies reduced pressure (e.g., 1-5 MPa) and/or a temperature profile designed to minimize whisker intergrowth or promote the formation of internal voids, for a shorter duration than robust panels (e.g., 30 minutes). This method yields panels with deliberately weakened internal cohesion, allowing for easier cutting, controlled fracture along pre-determined lines, or rapid disintegration under minimal external force for applications requiring temporary barriers, disposable structures, or enhanced safety features.

flowchart LR
    A[Reactive MgO + Salt] --> B(Mixing)
    C[Modified Hydroxyl Slurry (Inhibitors / Low Conc)] --> B
    D[Sacrificial Fillers] --> B
    B --> E[Damp Composition (Weakened Whisker Potential)]
    E --> F{Mold Application}
    F --> G[Reduced P (1-5 MPa) & Temp Profile (min whisker growth)]
    G --> H[Core Layer (Controlled Failure / Easy Disassembly)]

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Derivatives of Independent Claim 14: Detailed Method for Producing Panels

Independent Claim 14: A method for producing a panel, comprising: a1) providing a composition comprising at least one magnesium oxide; b1) providing a brine comprising at least one magnesium salt and water; c1) mixing of said brine into said composition of magnesium oxide such that a magnesium oxide damp composition is formed; d1) preferably adding at least one aqueous slurry comprising at least one compound comprising at least two hydroxyl groups to the magnesium oxide composition; e1) subjecting the magnesium oxide damp composition to at least one screening step f1) applying at least one layer of the magnesium oxide composition upon a mold; and g1) subjecting the layer of magnesium oxide damp composition to a force having a pressure of at least 7 MPa at a temperature at least in the range of 45 to 55 degrees Celsius for at least 1 hour such that a core layer comprising an upper core surface and a lower core surface is obtained.

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Derivative 14.1: Roboticized Layering with Vibratory Compaction

Enabling Description:
A method where steps (e1) and (f1) are automated using robotic systems and vibratory compaction. After screening (e1), the damp magnesium oxide composition is conveyed to a multi-axis robotic arm equipped with a precision layering tool. This robotic arm applies a plurality of thin layers of the damp composition onto a continuously moving conveyor-mold (f1), allowing for precise thickness control and localized variations if desired. Each applied layer is subjected to vibratory compaction (e.g., 20-50 Hz, 0.5-1.5 g acceleration) to remove residual air pockets and enhance initial density, prior to the main pressing step (g1). This pre-compaction by vibration, integrated with robotic layering, ensures a highly uniform, void-free damp composition before the final high-pressure curing, leading to a core layer with exceptional density consistency and an even distribution of the whisker-phase magnesium crystal structure.

sequenceDiagram
    participant SC as Screened Composition
    participant R as Robotic Arm (Layering Tool)
    participant CM as Conveyor-Mold
    participant VC as Vibratory Compactor
    participant PC as Pressing & Curing (Step g1)

    SC->>R: Feed Damp Composition
    R->>CM: Apply Layer 1
    VC->>CM: Vibrate Layer 1
    R->>CM: Apply Layer 2
    VC->>CM: Vibrate Layer 2
    Note over R,VC: Repeat for N layers
    CM->>PC: Convey Multi-Layered Damp Composition
    PC->>PC: Apply Force & Temp (Final Cure)

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Derivative 14.2: In-Line Rheological Control and Additive Adjustment

Enabling Description:
A method incorporating in-line rheological measurement and feedback control for steps (c1) and (d1). After mixing brine into magnesium oxide (c1) to form the damp composition, and prior to adding the hydroxyl slurry, the damp composition's rheological properties (e.g., viscosity, yield stress) are continuously measured using an in-line rheometer. An automated system (d1) then adjusts the dosage and/or concentration of the aqueous slurry comprising the hydroxyl compound (e.g., malic acid) based on this real-time rheological data. This ensures that the damp composition maintains optimal workability and consistency for subsequent screening and molding, while precisely controlling the hydroxyl additive's effect on crystal nucleation. This feedback loop minimizes batch-to-batch variations in whisker growth potential, leading to highly consistent panel cores.

graph TD
    A[Magnesium Oxide] --> B{Mixing with Brine (c1)}
    B --> C(Magnesium Oxide Damp Composition)
    C --> D[In-Line Rheometer]
    D -- Rheological Data --> F(Control System)
    E[Hydroxyl Slurry Supply] --> G(Additive Dosing Pump)
    F -- Adjust Signal --> G
    G --> C
    C -- To Screening (e1) --> H[Screened Composition]

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Derivative 14.3: Smart Mold System with Embedded Temperature and Strain Sensors

Enabling Description:
A method utilizing a "smart mold" system during step (g1) to achieve optimized curing and structural integrity. The mold (f1) is equipped with a dense array of embedded temperature sensors (e.g., thermocouples, RTDs) and micro-strain gauges across its surface and within the mold cavity. During the application of force and temperature (g1), these sensors provide real-time, spatially resolved data on the exothermic hydration reaction, heat distribution, and localized stress/strain development within the magnesium oxide damp composition. An external control system continuously processes this sensor data and dynamically adjusts the applied pressure (e.g., 7-20 MPa with localized actuators) and heating elements to prevent hot spots, ensure uniform curing, and mitigate internal stresses that could lead to micro-cracking or non-uniform whisker growth. This approach maximizes the volume of whisker-phase formation and overall panel strength by adapting the curing environment to the material's real-time state.

graph TD
    A[Magnesium Oxide Damp Composition Layer] --> B(Smart Mold System)
    B -- Embedded Temp/Strain Sensors --> C{Real-time Data Acquisition}
    C -- Data Processing --> D(Dynamic Control Unit)
    D -- Adjust Pressure/Heat --> E[Actuators & Heating Elements (Mold)]
    E --> B
    B --> F[Optimized Core Layer]

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Derivative 14.4: Pre-stressed Curing Method with Variable Pressure Application

Enabling Description:
A method for producing panels with intrinsic pre-stress, enhancing their flexural strength and crack resistance. After applying the damp composition to the mold (f1), step (g1) involves a multi-stage pressing process. Initially, a high isotropic pressure (e.g., 15 MPa) is applied at 45°C for a short duration (e.g., 1 hour) to achieve initial densification and whisker nucleation. Subsequently, the pressure is reduced and applied anisotropically (e.g., differential pressure across orthogonal axes) or through tensioning elements embedded in the mold, to induce a controlled pre-stress within the curing core layer as the whisker crystals grow and interlock. The temperature is maintained at 50-55°C during this anisotropic phase for several hours. The resulting core layer retains this pre-stress after demolding, making it highly resistant to bending and tensile forces, effectively utilizing the strength of the whisker network more efficiently.

stateDiagram-V2
    [*] --> Damp_Composition_in_Mold
    Damp_Composition_in_Mold --> Isotropic_Compaction: 15 MPa, 45C, 1 hr
    Isotropic_Compaction --> Anisotropic_Prestress_Cure: Reduced P (Anisotropic), 50-55C, Several hrs
    Anisotropic_Prestress_Cure --> Demolding
    Demolding --> Pre-stressed_Core_Layer
    Pre-stressed_Core_Layer --> [*]

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Derivative 14.5: Self-Healing Panel Production Method

Enabling Description:
A method to produce self-healing magnesium oxycement panels. During step (d1), in addition to the hydroxyl compound slurry, microcapsules containing a healing agent (e.g., an epoxy resin or a reactive magnesium salt solution) are uniformly dispersed within the magnesium oxide damp composition. These microcapsules are designed to rupture upon localized micro-cracking in the cured panel. Step (g1) is performed at 45-55°C and at least 7 MPa, ensuring the formation of the primary whisker-phase crystal structure while the microcapsules remain intact. When a crack forms in the final panel, the microcapsules rupture, releasing the healing agent, which then reacts with the exposed magnesium oxycement matrix or cures to fill the crack, restoring structural integrity and prolonging the panel's service life. The hydroxyl compound in the initial slurry can also act as a catalyst for the healing agent.

flowchart LR
    A[Reactive MgO + Salt] --> B(Mix)
    C[Hydroxyl Slurry] --> B
    D[Healing Agent Microcapsules] --> B
    B --> E[Damp Composition with Microcapsules]
    E --> F[Screening & Mold Application]
    F --> G{Pressing & Curing (45-55C, >=7 MPa)}
    G --> H[Self-Healing Core Layer]
    H -- Micro-cracks --> I{Microcapsule Rupture & Healing Agent Release}
    I --> H

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Derivative 14.6: 3D Printing of Graded Whisker-Phase Structures

Enabling Description:
A method for additive manufacturing (3D printing) of panel core layers with spatially graded whisker-phase crystal structures. Steps (a1), (b1), (c1), and (d1) are performed to create a rheologically controlled magnesium oxide damp composition (or paste) suitable for extrusion-based 3D printing. The hydroxyl compound slurry is metered precisely to allow for regional variations. Instead of a single mold application (f1), the 3D printer extrudes the damp composition layer-by-layer according to a digital model, building the core layer with programmed variations in composition or porosity. During or immediately after printing each layer, localized heating (e.g., IR laser, microwave) to 45-55°C and compaction (e.g., roller, vibratory head achieving >=7 MPa) are applied in-situ (g1). This enables the formation of customized whisker-phase concentrations and orientations at different points within the panel, allowing for optimized strength in high-stress areas and reduced density in low-stress areas, or creation of intricate internal geometries for acoustic or thermal performance.

graph TD
    A[Magnesium Oxide Damp Composition Paste] --> B{3D Printer Extrusion Head}
    B -- Layer-by-Layer Deposition --> C[Printed Panel Layer]
    C -- In-situ Localized P/T (>=7 MPa, 45-55C) --> D[Cured Layer with Graded Whisker Structure]
    D -- Repeat for N layers --> E[Finished Core Layer (3D Printed)]