Three-dimensional printing process for the production of near-standard components with property gradients

• Applicants: Professor Dr.-Ing. Eckart Uhlmann; Professor Dr.-Ing. Manfred H. Wagner
• Subject Area: Plastics Engineering
• Term: from 2010 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 163148346

Plastic components which have local gradients in mechanical properties and consist of only one material could not be produced with additive manufacturing processes yet. Due to process-related constraints concerning the material selection, the application of additive manufacturing for producing functional prototypes is limited. To produce such interfacial-free property transitions, piezoelectric based inkjet printing technology was used in the first project phase. This printing technology in combination with a material system based on polyurethanes with two different polyols and polyisocyanate as reactants a gradation of properties inside of a component is possible. In the first research period, initial samples with linear and areal characteristic gradients have been produced by using the printing technology. Goal of the proposed second project phase is the development of the printing process for manufacturing components with spatially variable material properties. Thereby, it is intended to build up superimposed layers as well as spatially distinct gradients of mechanical property. The generation of several layers necessitates a matching between the used material components and the catalysts/inhibitors in terms of their reaction rate. Therefore, the reaction rate of the involved components has to be adjustable according to the printing speed in z-direction. Additionally, measurement methods need to be evaluated to prove the generated local material properties and also to provide a process control concerning the whole chemical reaction.

• DFG Programme: Research Grants