Design and Development of Sustainable Polyurethane Foam: A Proof-of-Concept as Customizable Packaging for Cultural Heritage Applications

World cultural heritage is an invaluable resource and must be preserved. Conventional packaging materials, such as polystyrene, polyurethane (PU) foams, paper-like tissue, and nylon fabric, are petrol-based. According to Agenda 2030, and Green Deal directives, the development of alternative bio-based materials has gained significant scientific and technological relevance. In this scenario, a new sustainable packaging material for safe storage and transporting of the artifacts, based on a sustainable PU foam filled with 6 wt% of Zeolite 4A, is proposed. Zeolite 4A dispersion into PU matrix imparts higher compression strength and energy absorption capability with respect to unloaded materials (7-fold increase), owing to its remarkable cell nucleating effect. The proposed foam can adsorb water vapor, up to 29 wt%, thus contributing to regulating the humidity around the artifact. A remarkable advantage of the developed foam is the possibility to use it as plaster for precisely casting the article to protect, resulting in strongly improved handling, protection, and transportation safety with respect to conventional packaging solutions. A proof-of-concept workflow is proposed, consisting of: 1) three-dimensional (3D) scanning of the original artifact; 2) its replication through 3D printing; 3) the use of such a replica to prepare a tailored cast of the artifact shape.