Beschreibung
Additive manufacturing of thermoplastics or metals is a well approved sustainable process for obtaining rapidly precise and individual technical components. Except for crosslinked silicone rubber or thermoplastic elastomers, there is no way of manufacturing elastomers. Based on the development of the Additive Manufacturing of Elastomers (AME) – process, the material group of rubber based cured elastomers may get first access to the process field of 3D-printing. The printing and crosslinking of the rubber is separated in two steps: First the printing is realized by extrusion of the rubber by using a twin screw extruder, working according to a derived Fused-filament-fabrication (FFF) principle. In the second step the component is vulcanized in a high pressure hot-air autoclave. Due to the plastic flow behavior of non-crosslinked rubber materials a thermoplastic shell is needed to keep the geometry and position of the extruded rubber in shape. In this way one layer of thermoplastic and one layer of rubber are printed alternatingly until the component is finished. Afterwards the manufactured binary component is placed in the autoclave to obtain the elastomer after vulcanization under hot air and high pressure atmosphere. The thermoplastic shell can be removed from the elastomer and recycled afterwards. The high viscosity of rubber during processing compared to conventional thermoplastics and the instable shape after extrusion is challenging in the development of the AME. This contribution will show the modified 3D-printer, explain the printing process from the designed component, via shell generation, to the vulcanized component and show first printed components.
