Tangent Tech LLC v. Renew Plastics LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Tangent Technologies LLC (Illinois)
  • Defendant: RENEW Plastics, LLC (Wisconsin)
  • Plaintiff's Counsel: McDermott Will & Schulte LLP
• Case Identification: 1:26-cv-01165, E.D. Wis., 07/01/2026
• Venue Allegations: Venue is alleged to be proper because the Defendant, RENEW Plastics, LLC, is a Wisconsin company with its principal place of business in the Eastern District of Wisconsin and therefore resides in the district.
• Core Dispute: Plaintiff alleges that Defendant's polymer lumber products infringe two utility patents and two design patents related to a method for manufacturing polymer boards with a simulated wood-grain appearance that is visible throughout the product's core.
• Technical Context: The dispute centers on technology for manufacturing synthetic lumber that maintains a wood-grain appearance even after being cut or shaped, addressing a limitation of prior-art products where the grain was only a surface-level feature.
• Key Procedural History: The complaint alleges that Plaintiff provided Defendant with pre-suit notice of infringement via a letter dated May 28, 2026, which included claim charts. Defendant allegedly acknowledged receipt of this letter but did not cease the accused activities.

Case Timeline

Date	Event
2015-08-24	Priority Date for '350 and '384 Patents
2016-08-24	Filing/Priority Date for '234 and '235 Design Patents
2018-05-29	'234 and '235 Patents Issued
2021-04-20	'350 Patent Issued
2026-05-28	Plaintiff sends notice letter to Defendant
2026-06-04	Defendant acknowledges receipt of notice letter
2026-06-16	'384 Patent Issued
2026-07-01	Complaint Filing Date

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

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

The Invention Explained

• Problem Addressed: The patent's background describes an issue with existing composite and plastic lumber where any wood-grain appearance is "only skin deep" Compl. ¶¶8-9 '350 Patent, col. 1:34-37 Cutting or shaping these products exposes a "standard fiber-filled, homogenous core," destroying the aesthetic Compl. ¶¶8-9 '350 Patent, col. 1:36-37 Prior attempts to create a through-core grain allegedly resulted in inconsistent patterns with "breaks or gaps" '350 Patent, col. 2:12-14
• The Patented Solution: The invention uses a co-extrusion process where at least two different colored polymers are combined and then fed through a specialized "flow divider" containing a series of twisted section inserts '350 Patent, col. 4:51-52 '350 Patent, Fig. 1 This process arranges the polymers into continuous, alternating layers that form a consistent, simulated wood-grain pattern throughout the entire body of the polymer board '350 Patent, col. 3:25-4:52 '350 Patent, abstract
• Technical Importance: This technology allows for the creation of a durable, synthetic wood substitute that can be worked like natural lumber (e.g., cut, routed, shaped) while maintaining a consistent wood-grain appearance on newly exposed surfaces Compl. ¶¶8-9

Key Claims at a Glance

• The complaint asserts independent claims 1 and 10 Compl. ¶27
• Claim 1 (Board):
  • A simulated natural wood-grained polymer board.
  • Comprising a first set of polymer layers with a first colorant and a second set of polymer layers with a different, second colorant.
  • A majority of the layers in each set extend along the entire length of the board.
  • A plurality of individual layers from both sets alternate within the board.
  • These alternating layers "extend along a substantially uninterrupted curvilinear path" from one side of the board to the other.
• Claim 10 (Substrate):
  • A simulated natural wood-grained polymer substrate with a core.
  • Comprising a first and second set of polymer layers with different colorants, with a majority of layers in each set being "substantially continuous" along the length.
  • Individual layers alternate "within the core" to form a wood-grained appearance "throughout the core."
  • A plurality of layers from "one of the first and second sets" extends along a "substantially uninterrupted curvilinear path" from one side to the other.
• The complaint reserves the right to assert additional claims Compl. ¶25

U.S. Patent No. 12,654,384 - "WOOD-GRAINED POLYMER SUBSTRATE", Issued June 16, 2026

The Invention Explained

• Problem Addressed: The '384 Patent addresses the same technical problem as the '350 Patent: creating a synthetic lumber product with a consistent, through-core wood grain that is not compromised by post-processing steps like cutting '384 Patent, col. 1:46-53 '384 Patent, col. 2:28-34
• The Patented Solution: The '384 Patent describes a polymer substrate made of interspersed layers of different colored polymers that form a wood-grained pattern '384 Patent, abstract A key feature is that a "cross-section of the substrate" exposes this internal wood-grained pattern, confirming that the aesthetic is not merely on the surface '384 Patent, col. 23:7-12
• Technical Importance: The invention provides a method for producing a synthetic material that robustly simulates natural wood, particularly the appearance revealed when wood is cross-cut.

Key Claims at a Glance

• The complaint asserts independent claims 1, 10, and 19 Compl. ¶49
• Claim 1 (Substrate):
  • A polymer substrate that simulates natural wood.
  • Comprising a first and second set of "substantially continuous" polymer layers with different colorants.
  • The substrate comprises a "wood-grained pattern formed of the first set of polymer layers and the second set of polymer layers."
  • Individual layers are "interspersed within the substrate to form the wood-grained pattern."
  • A plurality of layers from "at least one" of the sets extends along a "substantially curvilinear path" from one side to the other.
  • A "cross-section of the substrate" exposes the wood-grained pattern.
• Claim 10 (Substrate): Substantially similar to Claim 1, with a plurality of layers from "both the first and the second sets" extending along the curvilinear path.
• Claim 19 (Board): Substantially similar to Claim 1, but structured as a "board" with the curvilinear path extending from "the first set of polymer layers."
• The complaint reserves the right to assert additional claims Compl. ¶25

Multi-Patent Capsule: U.S. Patent No. D819,234 - "WOOD-GRAINED POLYMER BOARD", Issued May 29, 2018

• Technology Synopsis: The '234 Patent protects the ornamental design for a wood-grained polymer board Compl. ¶81 The design consists of the visual appearance of the grain pattern as shown in the patent's figures '234 Patent, FIG. 1 '234 Patent, FIG. 2
• Asserted Claims: The single design claim embodying the ornamental design shown in the figures '234 Patent, claim
• Accused Features: The overall visual appearance of the Accused Product is alleged to be "substantially the same" as the patented design in the eyes of an ordinary observer Compl. ¶82 The complaint provides a visual comparison of the Accused Product to Figure 2 of the '234 Patent Compl. ¶81

Multi-Patent Capsule: U.S. Patent No. D819,235 - "WOOD-GRAINED POLYMER BOARD", Issued May 29, 2018

• Technology Synopsis: The '235 Patent protects an alternative ornamental design for a wood-grained polymer board Compl. ¶92 The design is distinct from the '234 Patent and is defined by the specific visual characteristics depicted in its figures '235 Patent, FIG. 1 '235 Patent, FIG. 2
• Asserted Claims: The single design claim embodying the ornamental design shown in the figures '235 Patent, claim
• Accused Features: The complaint alleges that the design of the Accused Product, specifically the "EVOLVE in 'Charcoal Gray' color" with "Wood Grain" texture, is "substantially the same" as the design claimed in the '235 Patent Compl. ¶¶92-93

III. The Accused Instrumentality

Product Identification

The accused products are Defendant RENEW's "EVOLVE line of dimensional lumbar" Compl. ¶17

Functionality and Market Context

The complaint describes the Accused Products as "wood-alternative polymer lumber" in which a "wood-grain can been seen throughout the body of the lumber" Compl. ¶17 The allegations are based on "inspection" of the products, which is said to reveal alternating layers of differently colored polymers that form curvilinear paths through the board, creating a wood-grain effect that persists even when the board is viewed from its end Compl. ¶¶31-33 Compl. ¶54 Compl. ¶57 An annotated image in the complaint shows a cross-section of an Accused Product, highlighting the alleged internal layering that forms the wood grain Compl. ¶34

IV. Analysis of Infringement Allegations

'350 Patent Infringement Allegations

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...	The Accused Product is alleged to be a simulated natural wood-grained polymer board with defined sides, width, and length.	¶30	col. 7:5-10
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 complaint alleges inspection shows the Accused Product has a first set of polymer layers with a first colorant, the majority of which extend the full length of the board.	¶31	col. 7:11-14
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 complaint alleges inspection shows the Accused Product has a second set of polymer layers with a different colorant, the majority of which also extend the full length of the board.	¶32	col. 7:15-19
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 annotated image and inspection are alleged to show that layers of the two sets alternate and form a substantially uninterrupted curvilinear path from one side to the other.	¶33; ¶34	col. 7:43-48

An annotated image provided in the complaint visually maps the elements of Claim 1 onto a photograph of the Accused Product's cross-section Compl. ¶34

'384 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A polymer substrate that simulates natural wood extending along a first direction...	The Accused Product is alleged to be a polymer substrate simulating natural wood with defined sides and dimensions.	¶53	col. 23:49-56
a first set of polymer layers... being substantially continuous along the first direction;	Inspection of the first and second sides of the Accused Product is alleged to show a plurality of substantially continuous polymer layers of a first color.	¶54	col. 23:57-61
a second set of polymer layers... being substantially continuous along the first direction;	Inspection of the Accused Product is alleged to show a second plurality of substantially continuous polymer layers of a different color.	¶55	col. 24:1-5
wherein individual layers of the first and the second set of polymer layers are interspersed within the substrate to form the wood-grained pattern,	An inspection of a cross-section is alleged to show that individual layers of the two sets are interspersed within the substrate to create a wood-grained pattern.	¶57	col. 23:3-6
and a cross-section of the substrate exposing the wood-grained pattern.	Inspection of a cross-section cut perpendicular to the length is alleged to show that the substrate exposes the internal wood-grained pattern.	¶58	col. 23:7-12

An annotated image in the complaint purports to show how features of the Accused Product's cross-section meet the limitations of Claim 1 Compl. ¶59

• Identified Points of Contention:
  • Scope Questions: The infringement allegations for both utility patents rely heavily on terms like "substantially uninterrupted" ('350 Patent) and "substantially continuous" ('384 Patent). A central point of contention may be the degree of continuity required by these terms and whether any breaks, inconsistencies, or variations in the Accused Product's grain pattern fall outside the claim scope.
  • Technical Questions: The complaint's infringement theory is based on "inspection" of the final Accused Product Compl. ¶¶31-33 Compl. ¶¶54-58 This raises the evidentiary question of whether the observed wood-grain appearance is created by the claimed process of alternating distinct polymer layers, or if it results from a different manufacturing technique that achieves a visually similar outcome. The case may turn on whether discovery reveals a technical match in the underlying product structure and manufacturing method.

V. Key Claim Terms for Construction

For the '350 Patent:

• The Term: "substantially uninterrupted curvilinear path"
• Context and Importance: This term is central to defining the quality and consistency of the wood-grain effect. The degree to which a "path" can have interruptions (e.g., gaps, breaks, color blending) and still be considered "substantially uninterrupted" will be critical to the infringement analysis. Practitioners may focus on this term because the visual nature of wood grain often includes natural imperfections, and the scope of "substantially" will determine if such features in the accused product are covered.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification's use of "substantially" suggests that absolute, perfect continuity is not required. Language stating the grains extend with "minimal or no gaps" could be argued to permit some level of imperfection '350 Patent, col. 7:45-48
  • Evidence for a Narrower Interpretation: The patent contrasts the invention with prior art that produced "breaks or gaps" and "inconsistencies" '350 Patent, col. 2:12-14 This could support a narrower construction where "substantially uninterrupted" means a high degree of continuity without the flaws of the prior art. The drawings, such as FIG. 6, depict clean, continuous lines, which may also support a narrower view.

For the '384 Patent:

• The Term: "a cross-section of the substrate exposing the wood-grained pattern"
• Context and Importance: This limitation distinguishes the invention from surface-only treatments by requiring the pattern to be integral to the substrate's core. The dispute may hinge on what constitutes an exposed "wood-grained pattern" upon cross-sectioning.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification broadly states the process is for producing "a wood-grained appearance through a core of the board" '384 Patent, col. 2:16-18 This general statement could support a reading where any internal, non-homogenous color variation that resembles a grain qualifies.
  • Evidence for a Narrower Interpretation: The claim requires the exposed pattern to be "formed of the first set of polymer layers and the second set of polymer layers" '384 Patent, col. 23:65-24:2 This could support a narrower interpretation requiring the exposed pattern to be clearly composed of the distinct, alternating layers, not just random color variations or pockets. The complaint itself alleges a pattern formed by "interspersed" layers, suggesting this structure is key Compl. ¶57

VI. Other Allegations

• Indirect Infringement: The complaint alleges that RENEW actively induces infringement by "encouraging and instructing its customers and end users to use and/or sell the Accused Products" in an infringing manner Compl. ¶44 Compl. ¶76 Compl. ¶86 Compl. ¶97 It also alleges contributory infringement, stating the Accused Products are "specially made or adapted for infringing" and not a staple article of commerce Compl. ¶43 Compl. ¶75 Compl. ¶85 Compl. ¶96
• Willful Infringement: Willfulness is alleged based on RENEW's purported knowledge of the patents. For the '350, '234, and '235 patents, this knowledge is based on the pre-suit notice letter sent on May 28, 2026, and RENEW's alleged continuation of infringing activities after acknowledging its receipt Compl. ¶¶18-19 Compl. ¶41 Compl. ¶47 For the '384 Patent, knowledge is alleged from at least its issue date of June 16, 2026, and "certainly as of the filing and/or service of this complaint" Compl. ¶74

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

1. A central issue will be one of definitional scope: How will the court construe qualifying terms such as "substantially uninterrupted" and "substantially continuous"? The outcome of the infringement analysis for the utility patents will likely depend on whether the inevitable minor variations and imperfections in the accused product's grain fall within a reasonable interpretation of these terms.

2. A key evidentiary question will be one of structural and procedural equivalence: The complaint's allegations are based on visual inspection of the final product. A core question for discovery will be whether the accused product's internal structure is in fact composed of alternating, distinct polymer layers as claimed, or if its appearance is achieved through a different manufacturing process that falls outside the patent's specific teachings.

3. For the design patents, the case will turn on the "ordinary observer" test: Does the overall visual appearance of RENEW's EVOLVE lumber create a resemblance to the designs in the '234 and '235 patents that is "such as to deceive such an ordinary observer, inducing them to purchase one supposing it to be the other"? Compl. ¶82 Compl. ¶93