Kannengießer, LukasLukasKannengießerArne, WalterWalterArneBier, Alexander M.Alexander M.BierMarheineke, NicoleNicoleMarheinekeSchubert, Dirk WolframDirk WolframSchubertWegener, RaimundRaimundWegener2025-06-052025-06-052025https://publica.fraunhofer.de/handle/publica/48832810.1186/s13362-025-00168-x2-s2.0-85218006754For the simulation-based design of fiber melt spinning processes, the accurate modeling of the processed polymer with regard to its material behavior is crucial. In this work, we develop a high-speed elongational rheometer for Carreau-type materials, making use of process simulations and fiber diameter measurements. The procedure is based on a unified formulation of the fiber spinning model for all material types (Newtonian and quasi-Newtonian), whose material laws are strictly monotone in the strain rate. The parametrically described material law for the elongational viscosity implies a nonlinear optimization problem for the parameter identification, for which we propose an efficient, robust gradient-based method. The work can be understood as a proof of concept, a generalization to other, more complex materials is possible.entrueBoundary value problemElongational rheometerFiber spinningGeneralized Newtonian materialParameter identificationjournal article