The solvent to feed ratio is a parameter that is of great importance when designing and scaling-up a process . Generally solvent use is minimized due to its cost factor allowing for smaller reactors and separation units in the downstream processing . However, very low ratios can cause solubility problems with solid reactants. The effect of CEW:PA mass ratios between 4 and 30 are illustrated in Figure . We observed that the mass balances for a CEW:PA mass ratio of 4 and 5 was slightly outside of the 5% deviation range and that significantly less PA was dissolved compared to the 8.5 mass ratio. However, for CEW:PA mass ratios higher than 8.5, no significant dissolution improvement was observed (error bars overlap). A likely explanation for this observation is that the filaments easily agglomerate at CEW:PA mass ratios below 8.5 and the CEW cannot penetrate into the agglomerates. In contrast, for ratios ≥ 8.5 the filaments are dispersed in an excess of solvent facilitating their dissolution. Thus, a CEW:PA mass ratio of 8.5 can be seen as a very rational value.