Powder bed fusion printing process applied to the restoration of cultural heritage: Mechanical and durability experimental investigation of PA12

This paper evaluates the application of Multi Jet Fusion 3D printing technology, specifically using Polyamide 12 (PA12), for the creation of structural and decorative elements to restore gaps in architectural heritage. The research focuses on the material mechanical and durability properties, with experiments including tensile and three-point bending tests. The influence of printing color and protective varnish on mechanical performance is also analyzed, as these treatments may enhance both aesthetic appearance and durability in cultural heritage applications. Additionally, UV-B irradiation tests simulating outdoor exposure to investigate material degradation are carried out. The protective varnish does not significantly improve the mechanical properties, while the color of the 3D-printed PA12 specimens negatively influences the overall mechanical performance, though it remains within an acceptable range for the considered application. Based on encouraging experimental results, a case study involving the reconstruction of window cornices for the historic Palazzo Orsini in central Italy is presented, illustrating the potential of 3D printing for cultural heritage restoration.