One of Carbon's foundational dual-cure patents has survived a challenge from an unnamed competitor after a Board of Appeal of the European Patent Office (EPO) ruled in its favour.
Carbon's European Patent No. 3158400 is titled Methods of producing three-dimensional objects from materials having multiple mechanisms of hardening and was granted in 2022 after being filed around ten years ago.
The dual-cure technology combines light-based printing with a secondary thermal curing reaction, allowing Carbon's Digital Light Synthesis 3D printing technology to produce parts with 'properties tailored to the application needs.' Parts in automotive, healthcare, and consumer products are said to have been enabled with engineering-grade strength, elasticity, durability, and temperature resistance thanks to this technology, with 'top brands across the globe' benefiting.
After the patent was granted in 2022, an official challenge to its validity was made in 2023 by Oxon IP B.V on behalf of an unnamed competitor. Two separate third-party observations were also made during the examination period in 2019 and 2021. An initial decision in 2025 saw the patent survive but with dependent claims removed, with two appeals - one on 28 February 2025 and another on 3 March 2025 - lodged. Both of these appeals were then examined by the EPO Board of Appeal on September 24, 2026, with the patent being maintained in an amended form.
Carbon has since communicated on September 28 that the broadest claim of its European Patent No. 3158400 has been upheld, affirming the earlier EPO Opposition Division decision in 2025, and restored additional dependent claims that had been removed during the original opposition proceeding. This would suggest that at least one of the appeals lodged in Q1 2025 was made by Carbon.
“This decision confirms the strength and breadth of the innovation that is foundational to Carbon’s platform. Dual-cure chemistry enables the production of high-performance end-use products that previously were difficult or impractical to produce with other 3D printing technologies. We will continue to invest in and protect our innovations as we advance digital manufacturing," said Philip DeSimone, CEO of Carbon.
Carbon was represented in the proceedings by Mairi Rudkin and Donald McNab of Marks & Clerk, and is globally represented in patent prosecution matters by Myers Bigel and in patent litigation matters by Kathi Vidal and Dustin Edwards of Winston Taylor.
