NIST reference material aims to standardize photopolymer 3D printing
RM 8047 gives laboratories a common baseline for calibrating resin cure behavior
The National Institute of Standards and Technology (NIST) has made available Reference Material (RM) 8047, a standardized photoactive resin developed with the Photopolymer Additive Manufacturing Alliance (PAMA)—a joint initiative of NIST and RadTech International North America—to reduce measurement variance across laboratories working with photopolymer 3D printing.
Photopolymer 3D printing has relied on a “working curve” to ensure each resin layer cured deeply enough to bond without overexposure that degraded the material. Wide discrepancies among laboratories in measuring light penetration depth and critical exposure energy had limited commercial scaling, according to NIST, and RM 8047 was built as a uniform baseline for method validation.
“Our goal is to provide the advanced manufacturing sector with tools that assure users that their 3D-printed products are accurate and reproducible,” said Jason Killgore, Group Leader in the Applied Chemicals and Materials Division at NIST. “By establishing standard reference materials, we help eliminate measurement variance, allow operators to calibrate light sources safely, and give the industry the metrics needed for true commercial scalability.”
Material composition and testing
Each unit of RM 8047 consists of a 20-gram bottle of photoactive resin formulated with defined amounts of photoinitiator and photoabsorber.
To set the reference parameters, NIST led an interlaboratory study in which participants used three sets of NIST-built, calibrated light sources at 385-nanometer and 405-nanometer wavelengths, and the resulting cure-depth and radiant-exposure data were analyzed using the Jacobs Equation to map working curves.
A cross-sector alliance
“The deployment of RM 8047 represents a major milestone for the work of NIST and the Photopolymer Additive Manufacturing Alliance (PAMA),” said Callie Higgins, NIST Additive Manufacturing Program Coordinator and incoming PAMA Executive Chair.
“This initiative united over 30 cross-sector stakeholders to facilitate the interlaboratory coordination necessary to establish these standard test methodologies, accelerating open-source data infrastructure, publishing peer-reviewed research, and establishing safety protocols to advance the entire 3D printing market.”
