Sul4r Plus Kentucky LLC v. Feeco Intl Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Sul4r-Plus Kentucky, LLC (Kentucky)
  • Defendant: Feeco Intl, Inc. (Wisconsin)
  • Plaintiff’s Counsel: Bradley Arant Boult Cummings LLP
• Case Identification: 3:25-cv-00124, W.D. Ky., 02/28/2025
• Venue Allegations: Plaintiff alleges venue is proper because a substantial part of the events giving rise to the claim, including the supply of equipment and commissioning services by Defendant to Plaintiff's predecessor-in-interest, occurred in the Western District of Kentucky.
• Core Dispute: Plaintiff seeks a declaratory judgment that the named inventors on two of its patents are the sole and correct inventors, countering Defendant's assertions of co-inventorship and intellectual property misappropriation.
• Technical Context: The technology concerns methods and products for converting synthetic gypsum, an industrial byproduct, into a granular fertilizer suitable for agricultural use.
• Key Procedural History: The action was precipitated by correspondence from Defendant asserting that information it provided to Plaintiff's predecessor was used in the patents-in-suit, demanding that it be credited as a co-inventor, and threatening litigation. This correspondence created the "actual controversy" required for a declaratory judgment action.

Case Timeline

Date	Event
2012-04-30	Charah (Plaintiff's predecessor) and FEECO enter into a Mutual NDA.
2012-06-18	Charah agrees to purchase equipment from FEECO for its Kentucky plant.
2012-07-09	Charah and FEECO representatives meet to negotiate equipment provisioning.
2012-08-08	Priority date for both patents-in-suit (based on provisional application).
2013-08-08	Application filed for what would become the ’638 Patent.
2013-12-05	Assignment of patent rights from inventors to Charah recorded at USPTO.
2016-07-29	Application filed for what would become the ’977 Patent.
2017-06-21	Assignment of patents from Charah to SUL4R-PLUS recorded at USPTO.
2018-01-23	U.S. Patent No. 9,873,638 issues.
2018-03-20	U.S. Patent No. 9,919,977 issues.
2025-01-23	FEECO's president emails SUL4R-PLUS asserting improper use of its IP.
2025-02-04	SUL4R-PLUS emails FEECO, disputing the IP claim.
2025-02-14	FEECO emails SUL4R-PLUS, alleging co-inventorship and threatening litigation.
2025-02-28	Complaint for Declaratory Judgment filed.

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,873,638, "Synthetic gypsum fertilizer product and method of making," issued January 23, 2018

The Invention Explained

• Problem Addressed: The patent’s background section explains that synthetic gypsum, an industrial co-product, has a very fine particle size which makes it retain moisture and handle poorly, preventing its effective use in agriculture with conventional spreading equipment (ʼ638 Patent, col. 1:49-61).
• The Patented Solution: The invention addresses this by describing a method and resulting product where fine synthetic gypsum is combined with a specific binder composition (lignosulfonate) and then processed into durable pellets of a specified size range and crush strength. This process, illustrated conceptually in Figure 2, transforms the difficult-to-handle powder into a granular product compatible with standard farm machinery (ʼ638 Patent, Abstract; col. 2:11-31).
• Technical Importance: The patented process provides a method to beneficially recycle large quantities of an industrial byproduct for agricultural use, which would otherwise be disposed of in landfills (ʼ638 Patent, col. 1:61 - col. 2:4).

Key Claims at a Glance

The complaint disputes inventorship of the patents as a whole, without specifying claims. The broadest independent claims, Claim 1 (a method) and Claim 11 (a product), are representative of the patented technology.

• Independent Claim 1 (Method) requires:
  • Feeding synthetic gypsum to a forming device.
  • Feeding a binder composition comprising lignosulfonate having 18% to 40% solids to the forming device.
  • Forming the material into pellets with a mean pellet size guide number (SGN) from approximately 100 to 500.
  • The resulting pellets must have a crush strength from approximately 2 lbf to 12 lbf.
• Independent Claim 11 (Product) requires:
  • Pellets comprising synthetic gypsum and a lignosulfonate binder.
  • The binder must initially have 18% to 40% solids at the time of contact.
  • The pellets must have a mean SGN from approximately 100 to 500.
  • The pellets must have a crush strength from approximately 2 lbf to 12 lbf.

U.S. Patent No. 9,919,977, "Synthetic gypsum fertilizer product and method of making," issued March 20, 2018

The Invention Explained

• Problem Addressed: The ʼ977 Patent addresses the same problem as its parent '638 Patent: the difficulty of handling and applying fine-particle synthetic gypsum as an agricultural product (ʼ977 Patent, col. 1:59 - col. 2:2).
• The Patented Solution: This invention discloses a more detailed process that adds thermal pre-treatment steps. The method involves drying the raw synthetic gypsum to less than 2% moisture, then "calcining" it (heating to drive off water molecules) to form either alpha- or beta-hemihydrate. This processed material is then mixed with a binder and formed into pellets using an extruder, as shown in the process flow diagrams of Figure 3 (ʼ977 Patent, Claim 1; col. 15:50 - col. 16:13).
• Technical Importance: The addition of specific drying and calcination steps suggests a method for achieving greater control over the chemical and physical properties of the intermediate material, which may in turn improve the characteristics of the final fertilizer pellet.

Key Claims at a Glance

The complaint disputes inventorship of the patent as a whole. The broadest independent claim, Claim 1 (a method), is representative of the patented technology.

• Independent Claim 1 (Method) requires:
  • Drying synthetic gypsum to less than 2% moisture at a temperature below 262° F.
  • Calcining the dried gypsum to convert it into alpha- or beta-hemihydrate.
  • Mixing the calcined gypsum with a binder composition.
  • Feeding the mixture to a forming device comprising an extruder.
  • Forming pellets with a mean SGN from approximately 150 to 300 and a crush strength from approximately 2 lbf to 12 lbf.

III. Key Claim Terms for Construction

The complaint does not provide sufficient detail for an analysis of key claim terms. The dispute, as articulated in the complaint, centers on the global question of who conceived the inventions, rather than on the specific meaning of any particular claim term. The core issue is factual—who contributed novel ideas—not legal construction of the claims' language at this stage.

IV. Other Allegations

The complaint is a declaratory judgment action focused on correcting inventorship, which is a fundamentally different allegation than infringement. The central controversy is based on a series of communications between the parties.

No probative visual evidence provided in complaint.

• Plaintiff’s Factual Allegations (for Sole Inventorship): The complaint alleges that the named inventors, Ginn and Gray, conceived of the inventions and reduced them to practice prior to any substantive discussions with Defendant FEECO (Compl. ¶¶ 22, 23). The inventors allegedly performed their initial research and development, including testing pelletized samples, at a third-party facility (Mars Minerals) (Compl. ¶23). The complaint further asserts that Plaintiff's predecessor, Charah, engaged FEECO for the limited purpose of purchasing "mixing and pelletizing equipment" and that FEECO was explicitly advised its role would not include drying equipment (Compl. ¶26). To support this, Plaintiff alleges that a FEECO representative admitted to having "no prior experience with synthetic gypsum" at the time (Compl. ¶27).

• Defendant’s Alleged Counter-Claims (for Co-Inventorship): The complaint states that the dispute arises from FEECO's direct claims of co-inventorship. FEECO's president is alleged to have asserted in writing that "details from [Plaintiff's] patents nearly perfectly align with the information transmitted from FEECO," that "certain details of your patents were falsely claimed as original to Charah," and that for the patents "to hold water, FEECO should have been given credit and listed as a co-applicant and inventor" (Compl. ¶33). FEECO also allegedly accused Plaintiff's predecessor of having "misappropriate[d] FEECO Intellectual property" and threatened litigation to "remedy the misappropriation" (Compl. ¶¶ 33.c, 34). These assertions by FEECO form the basis for the "actual controversy" that gives the court jurisdiction to hear Plaintiff's declaratory judgment action.

V. Analyst’s Conclusion: Key Questions for the Case

The resolution of this case does not turn on claim construction or infringement analysis, but on the factual and legal standards for inventorship. The central questions for the court will be:

• A core issue will be one of inventive contribution: The court must determine what, if any, specific contributions FEECO's employees made to the "conception" of the subject matter claimed in the '638 and '977 patents. Did FEECO's input constitute a significant contribution to the claimed invention's "definite and permanent idea," or was it limited to the non-inventive activities of a skilled equipment vendor?

• A key evidentiary question will be one of chronology and corroboration: The case will likely depend on which party can produce more persuasive corroborating evidence (e.g., lab notebooks, emails, internal reports, third-party testimony) to support its timeline of events. Specifically, the court will examine when the key inventive concepts were conceived by Ginn and Gray versus what specific technical information was transmitted from FEECO to Charah under their non-disclosure agreement.