Key Takeaways
- The Unified Patent Court (UPC) denied Stratasys’ request for a preliminary injunction against Bambu Lab’s H2C printer on 24 April 2026.
- The European patent (EP 2964450) and the U.S. patent (US 9,421,713) belong to the same family, but the courts reached opposite conclusions.
- The decisive factor was the interpretation of “layer‑by‑layer” – the UPC required a single material per horizontal layer, a condition the H2C’s mixed‑material purge tower does not meet.
- The U.S. jury awarded Stratasys $27.6 million in damages, while the European proceeding remains open for a full merits trial.
- The split outcome signals that patent strategy in additive‑manufacturing will need to address jurisdiction‑specific claim language and technical nuances.
1. Background: The Same Patent Family, Two Courts
Stratasys sued Bambu Lab for allegedly infringing its purge‑tower technology, a method that builds a sacrificial “tower” to clean the nozzle between material changes.
- U.S. case – Patent No. US 9,421,713; verdict delivered 12 May 2024; damages $27.6 million.
- European case – Patent No. EP 2964450; heard by the Hague Local Division of the Unified Patent Court (UPC) on 24 April 2026.
Both patents describe a purge tower constructed “layer by layer” using a single extrusion material per layer. The dispute centers on whether Bambu Lab’s H2C printer, released in 2025, complies with that wording.
2. UPC Hearing: Why the Injunction Was Refused
2.1 Evidence at the Preliminary Stage
The UPC examined the H2C’s purge‑tower algorithm, which can blend two or more filament colors within a single horizontal slice. The court concluded that, based on the documents submitted, the H2C’s implementation “more likely falls outside the literal scope of the claim.”
2.2 The “Layer‑by‑Layer” Definition
- Court’s reading (EU): Each horizontal layer of the tower must be printed with one homogeneous material before the next layer begins.
- Bambu Lab’s approach (H2C): The firmware allows interleaved extrusion of different filaments inside the same layer, creating a gradient‑style purge tower that still clears the nozzle but does not respect the single‑material rule.
The UPC emphasized that this subtle distinction is technically material because the claim’s novelty hinges on the uniformity of each layer.
3. Technical Contrast: H2C vs. Stratasys’ Reference Model
| Feature | Stratasys Reference (US 9,421,713) | Bambu Lab H2C (2025) |
|---|---|---|
| Purge‑tower height | 150 mm (standard) | 150 mm (identical) |
| Material per layer | 1 filament (single colour) | Up to 4 filaments blended per layer |
| Extruder count | 2 (dual‑material) | 4 (quad‑extruder) |
| Build volume | 300 × 300 × 400 mm | 300 × 300 × 400 mm |
| Firmware control | Fixed‑layer sequence | Dynamic, on‑the‑fly mixing |
| Patent claim reliance | “Each layer formed with a single material” | “Mixed material within a layer” |
The table illustrates that while the overall geometry is identical, the material‑mixing strategy diverges sharply—a point that tipped the European decision.
4. United States vs. Europe: Verdict Comparison
| Aspect | United States (Jury) | Europe (UPC) |
|---|---|---|
| Outcome | Injunction granted; $27.6 M damages | Preliminary injunction denied |
| Key legal test | Literal infringement + willful infringement | Likelihood of infringement based on claim scope |
| Interpretation of “layer‑by‑layer” | Broad – any sequential deposition counted | Narrow – each horizontal slice must be homogeneous |
| Next steps | Stratasys pursuing appeal (Fed. Cir.) | Full merits trial scheduled for 2028 |
The divergent rulings underscore how claim construction can vary between jurisdictions, even for identical technical disclosures.
5. Ongoing U.S. Patent Challenges
Stratasys has filed a re‑examination request with the USPTO, arguing that the H2C’s mixed‑layer technique is an obvious design‑around. Bambu Lab, in turn, filed an inter partes review (IPR) seeking to invalidate key claim elements of US 9,421,713. Both proceedings are expected to conclude by late 2027, potentially reshaping the enforceability of the patent family worldwide.
6. What This Means for the 3‑D‑Printing Landscape
- Design‑around incentives – Manufacturers may increasingly adopt multi‑material layer strategies to sidestep “single‑material per layer” claims.
- Jurisdiction‑specific drafting – Patent attorneys are likely to craft claim language that survives both the U.S. “broad literal” test and the European “strict layer uniformity” standard.
- Risk management – Companies planning global launches must budget for parallel litigation tracks, as a win in one market does not guarantee protection elsewhere.
Bottom Line
The Stratasys‑Bambu Lab clash illustrates that identical patents can yield opposite legal outcomes when
