Process-Dependence Guidance

3Dresyns® photopolymer resins are process-dependent systems. This means that final part performance and safety outcomes are determined by the complete workflow (printing + cleaning + post-curing + finishing + final cleaning), not by the liquid resin alone.

For applications involving prolonged skin contact, the goal of the workflow is to reach the maximum achievable degree of conversion under controlled and validated processing conditions and to reduce unreacted species, extractables and leachables to acceptable levels for the intended use.

Workflow parameters that can influence conversion and extractables/leachables

Printer and optical output: wavelength, optical power at the vat, uniformity, optical aging, and calibration directly impact conversion and curing depth.
Exposure strategy: layer thickness, exposure time, bottom layers, rest times, and overcure margins influence network formation, shrinkage, and residual species.
Part geometry: thickness, internal channels, hollow designs, venting, and surface area-to-volume ratio affect light penetration, thermal gradients, and cleansing efficiency.
Cleaning chemistry and bath management: solvent type, temperature, bath contamination, replacement frequency, agitation/ultrasound, and rinse steps affect residue removal and surface chemistry.
Drying: inadequate drying before post-curing can trap cleaning fluids or residues and may influence conversion and surface properties.
Post-curing: light dose (intensity, time, distance), oxygen inhibition at the surface, and, when required, thermal post-curing can affect conversion and residual unreacted species.
Colored or opaque prints: reduced light penetration may require additional thermal post-curing or adapted post-processing to support conversion in internal zones.
Finishing operations: sanding, polishing, tribofinishing, or blasting can modify surface chemistry and may change the extractables/leachables profile.
Final cleaning and handling: contamination control, gloves, packaging materials, and storage conditions can introduce residues or change surface state.
Sterilization (if applicable): sterilization method and parameters can alter polymer networks, surface chemistry, and aging behavior.

Validation expectation

Because these parameters can significantly influence conversion and extractables/leachables, users must validate the complete workflow on representative parts and under intended use conditions. Any deviation from a validated workflow should be evaluated by the user and may require re-validation.