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Fused deposition modelling (FDM) is an additive manufacturing technology commonly used for modelling, prototyping and production applications. The achievable surface roughness is one of its most limiting aspects. It is however of great interest to create well-defined (nanosized) patterns on the surface for functional applications such as optical effects, electronics or bio-medical devices. We used UV-curable polymers of different viscosities and flexible stamps made of poly(dimethylsiloxane) (PDMS) to perform Nanoimprint Lithography (NIL) on FDM-printed curved parts. Substrates with different roughness and curvature were prepared using a commercially available 3D printer. The nanoimprint results were characterized by optical light microscopy, profilometry and atomic force microscopy (AFM). Our experiments show promising results in creating well-defined microstructures on the 3D-printed parts.

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We present a systematic approach based on Kirchhoff’s laws that uses tensor algebra and analytical formulae obtained from constitutive equations for the analysis of flow resistance networks. The flow of a Carreau fluid in a flat die with inverted preland is analyzed in terms of mass flow, velocity, and residence time distributions. Viscous heating is taken into account by using an analytical model which depends on the Cameron number of the flow at different positions. Further, we report the results of a three-dimensional simulation, using the commercially available ANSYS Polyflow software, which are in good agreement with our numerical study.