In Figure , the compositions of the applied CEW-mixtures (see , who observed the dissolution of PA 6.6 in CEW being influenced by the composition of the solvent. In Figure , the blue and orange boxes mark the ternary compositions for swelling and dissolution of PA 6.6 taken from Rietzler et al. ( ) for reference. The red dot in Figure shows the composition which results after adding the antisolvent. This composition lies in the region where no dissolution of PA 6 filaments or PA 6.6 fibers was observed and therefore the whole amount of dissolved PA precipitates from the solution. Fig. Recoveries of PA 6 using various CEW compositions according to Table . Experiments were performed in 35 ml vessel, a CEW:PA mass ratio of 8.5, heated with ultrasound at a dissolution temperature of 75 • C for 3 h.