Tangent Tech LLC v. Recycled Plastics Industries LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Tangent Technologies LLC (Illinois)
  • Defendant: RPI Inc (Wisconsin)
  • Plaintiff’s Counsel: McDermott Will & Emery LLP
• Case Identification: 1:23-cv-00261, E.D. Wis., 05/18/2023
• Venue Allegations: Venue is alleged to be proper in the Eastern District of Wisconsin because the Defendant is a Wisconsin corporation that resides and has its principal place of business in the district.
• Core Dispute: Plaintiff alleges that Defendant’s plastic lumber products infringe one utility patent and two design patents related to methods and designs for creating a simulated wood-grain appearance that extends throughout the body of the lumber.
• Technical Context: The technology concerns the manufacturing of plastic lumber, a substitute for natural wood used in applications like decking and outdoor furniture, where achieving a realistic and durable wood-grain appearance is a key market differentiator.
• Key Procedural History: Plaintiff alleges it sent Defendant a cease-and-desist letter on February 15, 2022, which included claim charts and put Defendant on notice of the patents-in-suit. The complaint alleges that after acknowledging receipt of the letter, Defendant has not ceased its activities and has falsely informed customers that the dispute was "settled."

Case Timeline

Date	Event
2015-08-24	’350 Patent Priority Date
2016-08-24	’234 and ’235 Patents Priority Date
2018-05-29	’234 and ’235 Patents Issue Date
2021-04-20	’350 Patent Issue Date
2022-02-15	Plaintiff sends cease-and-desist letter to Defendant
2022-03-08	Defendant acknowledges receipt of letter
2023-05-18	Complaint Filing Date

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

U.S. Patent No. 10,981,350 - "WOOD-GRAINED POLYMER SUBSTRATE" (Issued Apr. 20, 2021)

The Invention Explained

• Problem Addressed: The patent’s background section describes prior art plastic lumber as having either a superficial, "skin deep" wood-grain appearance that exposes a homogenous core when cut, or an inconsistent internal pattern resulting from turbulent mixing processes that create gaps and irregularities. ( '350 Patent, col. 1:32-38, col. 2:5-15).
• The Patented Solution: The invention is a polymer board and a method for making it, which creates a simulated wood-grain effect throughout the entire substrate. This is achieved by combining streams of at least two different colored polymers and passing them through a series of "section inserts" that systematically divide and reorient the flow, creating distinct, alternating layers of color that extend through the core of the board. (’350 Patent, Abstract; col. 4:43-51, col. 5:4-15). The result is a board that can be cut or machined without losing its wood-grain appearance. (’350 Patent, col. 2:20-25).
• Technical Importance: This technology allows for the creation of a durable wood substitute that maintains its aesthetic appearance even after being cut, shaped, or worn down, addressing a key limitation of earlier composite lumber products. (’350 Patent, col. 1:16-29).

Key Claims at a Glance

• The complaint asserts independent claims 1 and 10.
• Independent Claim 1 requires:
  • A simulated natural wood-grained polymer board with defined sides and length.
  • A first set of polymer layers with a first colorant, with a majority extending the length of the board.
  • A second set of polymer layers with a different, second colorant, with a majority extending the length of the board.
  • A plurality of these layers from both sets alternating within the board and extending along a "substantially uninterrupted curvilinear path" from a first side to a second side.
• The complaint reserves the right to assert additional claims. (Compl. ¶23).

U.S. Patent No. D819,234 - "WOOD-GRAINED POLYMER BOARD" (Issued May 29, 2018)

The Invention Explained

• Problem Addressed: Design patents do not articulate a problem and solution in the same manner as utility patents. They protect the novel, non-obvious, and ornamental appearance of an article of manufacture.
• The Patented Solution: The ’234 Patent claims the specific ornamental design for a wood-grained polymer board, as depicted in its figures. The design is characterized by flowing, wavy lines of varying thickness that create a specific visual wood-grain texture on the board's surface. (’234 Patent, Figs. 1-2).
• Technical Importance: In consumer-facing products like decking, the specific aesthetic appearance is a primary driver of purchasing decisions, making the protection of a unique ornamental design commercially significant.

Key Claims at a Glance

• Design patents contain a single claim for the ornamental design as shown and described in the patent drawings.
• The complaint asserts infringement of this single claim. (Compl. ¶47).

Multi-Patent Capsule: U.S. Patent No. D819,235

• Patent Identification: U.S. Patent No. D819,235, "WOOD-GRAINED POLYMER BOARD," issued May 29, 2018.
• Technology Synopsis: The patent protects a specific ornamental design for a wood-grained polymer board. The claimed design consists of a distinct pattern of fine, generally parallel lines with some waviness, creating a different visual texture than the ’234 patent. (’235 Patent, Figs. 1-2).
• Asserted Claims: The single claim for the ornamental design as shown in the patent. (Compl. ¶58).
• Accused Features: The overall visual appearance of Defendant's "Nature plastic lumber" is alleged to be substantially the same as the design claimed in the patent. (Compl. ¶59-60).

III. The Accused Instrumentality

Product Identification

• The accused products are Defendant’s "Nature branded plastic lumber," which are offered in a variety of color variants. (Compl. ¶14). The complaint provides a marketing image showing ten different color options. (Compl. p. 4).

Functionality and Market Context

• The complaint alleges the accused products are "simulated natural wood-grained polymer" boards. (Compl. ¶28). The core of the infringement allegation is that the products are manufactured with an internal structure of alternating, different-colored polymer layers that extend through the board to create a wood-grain appearance, which Plaintiff alleges reads on the asserted patent claims. (Compl. ¶29-31, ¶34-37). The complaint alleges that both an "old design" and a "changed design" of the accused products infringe the patents-in-suit. (Compl. ¶17).

IV. Analysis of Infringement Allegations

’350 Patent Infringement Allegations

The complaint provides annotated photographs of the accused product to illustrate its infringement theory for claims 1 and 10. This annotated image shows labels pointing to the width, length, sides, and the internal layered structure of the accused lumber. (Compl. ¶32). A second annotated image similarly maps features of the accused product to the elements of claim 10. (Compl. ¶38).

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A simulated natural wood-grained polymer board having a first side and a second side spaced apart from the first side...	Defendant's Nature plastic lumber is alleged to be a simulated wood-grained polymer board with a first and second side.	¶28	col. 8:26-34
a first set of polymer layers extending along the length direction and containing a first colorant, a majority of the first set of polymer layers extending along the length of the entire board;	The accused product allegedly includes a first set of polymer layers with a first colorant, a majority of which extend from the first end to the second end.	¶29	col. 8:35-38
a second set of polymer layers extending along the length direction and containing a second colorant different than the first colorant, a majority of the second set of polymer layers extending along the length of the entire board;	The accused product allegedly includes a second set of polymer layers with a different colorant, a majority of which extend from the first end to the second end.	¶30	col. 8:39-42
wherein a plurality of individual layers of the first and second sets of polymer layers alternate within the board and extend along a substantially uninterrupted curvilinear path originating proximate the first side of the board and terminating proximate the second side of the board.	An inspection of the accused product allegedly shows that a plurality of layers of the two sets alternate within the board and extend along a curvilinear path from the first side to the second side.	¶31	col. 8:43-51

• Identified Points of Contention:
  • Scope Questions: A central dispute may concern the meaning of "substantially uninterrupted curvilinear path." The analysis may question whether the layering in the accused product meets this limitation or results from a different process that produces a structure outside the claim's scope.
  • Technical Questions: The complaint's allegations rely on "an inspection" of the accused product. (Compl. ¶29-31). A key question for the court will be what physical evidence, such as cross-sections and expert analysis, Plaintiff can produce to demonstrate that a "majority" of the layers extend the entire length of the board and that they "alternate" in the manner required by the claim.

’234 Patent Infringement Allegations

The complaint alleges infringement of the design patent under the "ordinary observer" test. (Compl. ¶49). To support this, it provides a side-by-side visual comparison of two different colors of the accused "RPI Nature Plastic Lumber" next to Figure 2 of the ’234 Patent. (Compl. ¶48). The allegation is that the resemblance between the accused product's design and the patented design is substantial enough to deceive an ordinary observer into purchasing one believing it to be the other. (Compl. ¶49).

• Identified Points of Contention:
  • The infringement analysis for a design patent is a fact-intensive comparison of the overall visual appearance. The key question is whether the visual impression of the accused product is "substantially the same" as the patented design. Defendant may point to perceived differences in the flow, density, or character of the wood-grain lines to argue that an ordinary observer would not be deceived.

V. Key Claim Terms for Construction

For the ’350 Patent:

• The Term: "substantially uninterrupted curvilinear path"

• Context and Importance: This term is critical as it defines the required structure of the color layers within the board's core. The interpretation of "substantially uninterrupted" and "curvilinear path" will likely be a central point of the infringement analysis, determining whether the graining pattern in the accused product meets this limitation.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language itself does not tie the "path" to a specific manufacturing method, suggesting any board with this resulting structure could infringe. The specification describes variations in patterns being possible. (’350 Patent, col. 6:44-48).
  • Evidence for a Narrower Interpretation: The specification heavily details a specific manufacturing process using helical "section inserts" to create the layers. (’350 Patent, col. 5:30-42, Fig. 5). A defendant may argue that the term should be construed in light of this disclosed embodiment, potentially limiting its scope to structures created by a similar process.

• The Term: "alternate within the board"

• Context and Importance: This term defines the relationship between the first and second sets of polymer layers. Practitioners may focus on this term because its construction will determine whether a strict, regular alternation is required or if a more complex or stochastic intermingling of layers falls within the claim scope.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification mentions the process promotes "polymer A/B blending 123 which produces multiple color combinations and layers," suggesting the alternation may not be perfectly distinct. (’350 Patent, col. 5:6-9).
  • Evidence for a Narrower Interpretation: The summary states that "first and second layers alternate within the substrate to form a wood-grained appearance," and the claims repeatedly distinguish between the "first set" and "second set" of layers, which may support an interpretation requiring a more structured, non-blended alternation. (’350 Patent, col. 2:37-39).

For the ’234 Patent:

Claim construction for design patents is not typically focused on individual terms. The analysis centers on the overall ornamental design as depicted in the drawings. The key legal question is one of infringement based on the "ordinary observer" test, rather than the construction of specific claim terms.

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement of infringement for all patents-in-suit, stating on information and belief that Defendant encourages and instructs customers to use and sell the accused products in a manner that infringes. (Compl. ¶42, 53, 64).
• Willful Infringement: The complaint alleges willful infringement based on Defendant's alleged pre-suit knowledge of the patents from a cease-and-desist letter sent on February 15, 2022. (Compl. ¶15, 39). The allegation of willfulness is further supported by the claim that Defendant continued its conduct after receiving notice and falsely told customers the matter had been "settled." (Compl. ¶16, 45, 56, 67).

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

1. A core issue will be one of claim scope and construction for the '350 utility patent: can the term "substantially uninterrupted curvilinear path", which is described in the patent as being created by a specific apparatus, be construed to cover the internal grain structure of the accused product, which may be made by a different process?
2. A second central issue will be a question of fact for both the utility and design patents: what does the physical and visual evidence show? For the '350 patent, can Plaintiff prove through product teardowns that the accused lumber meets the structural limitations of alternation and continuity? For the '234 and '235 design patents, are the accused designs, when viewed as a whole, "substantially the same" as the patented designs in the eyes of an ordinary observer?
3. A third key question will relate to willfulness: given the allegation that Defendant received a detailed cease-and-desist letter and subsequently told customers the dispute was "settled," the court will need to evaluate whether Defendant's post-notice conduct was objectively reckless and constitutes the kind of egregious behavior that warrants enhanced damages.