40 Manufacturing and producing of 3D printing; material treatment, namely, 3D printing; rental of 3D printers; additive manufacturing of parts, workpieces, prototypes, models, shapes, tools and other kinds of three-dimensional objects from powders, wires and dispersions, especially by means of vat photopolymerisation, material jetting, binder jetting, material extrusion, powder bed fusion (including but not limited to laser sintering, laser melting, electron beam sintering, heat sintering and electron beam melting), sheet lamination and directed energy deposition; custom additive manufacturing of moulded components by means of processes such as vat polymerisation, material jetting, 3D printing, material extrusion, powder bed fusion (including, but not limited to, laser sintering, laser melting, electron beam sintering, thermal sintering and electron beam melting), sheet lamination and directed energy deposition (DED); coating of workpieces, prefabricated parts, material webs, tools and parts of machines of metal, ceramics, plastics, fibre-reinforced plastics, in particular applying layers of materials of metal, of ceramic materials, of plastic and composites of two or more of these materials; manufacture and preparation of parts, prototypes, models, moulds and tools and other kinds of three-dimensional objects by means of a generative manufacturing process; manufacture of powders for generative manufacturing of three-dimensional objects, in particular by means of laser sintering, laser melting, electron beam sintering and electron beam melting; applying of functional protective layers to workpieces, prefabricated parts, material webs, tools and parts of machines, including pre- and post-treatment steps