Life-Cycle Assessment of Vat Photopolymerisation: Functional Units, System Boundaries, Inventory Quality and Uncertainty
Segurola, Juan
2026-08-21 · Report · Version 1.3
Vat photopolymerisation couples liquid photopolymer feedstocks, light-driven conversion, support generation, washing, drying, post-curing and material-management steps that are often omitted or represented inconsistently in environmental assessments. This makes VPP particularly vulnerable to apparently precise but structurally incomparable carbon-footprint results. The present engineering perspective develops a methodology for life-cycle assessment of VPP systems rather than claiming that VPP, bio-based resins or any particular post-processing route is intrinsically sustainable. The framework begins with ISO 14040 and ISO 14044 and incorporates VPP-specific evidence from energy models, reusable unit-process inventories and stereolithography case studies [1-8]. It treats the functional unit, reference flow and delivered performance as the first design decision; defines cradle-to-gate, gate-to-gate and cradle-to-grave boundaries; separates resin production, printing, machine utilisation, failed builds, washing, post-curing, consumables and end-of-life; and requires explicit treatment of recovered resin and reusable materials. Particular attention is given to proxy data for proprietary photopolymer chemistry, allocation of machine and solvent burdens, uncertainty in emerging material systems, and sensitivity to service life and grid electricity. A minimum VPP inventory and reporting template is proposed. Commercial 3Dresyns products are included only as implementation examples that create different inventory questions; they are not used as evidence of lower environmental impact. The central conclusion is that environmental superiority in VPP is a result of a defined comparison, not an intrinsic material attribute.