© 2022 The Textile Institute.Nanofibers are high surface-to-volume ratio structures that are widely used today. Due to rising demand, the obtaining of desired structures requires the use of various polymers in the electrospinning process as well as the control of their parameters. In this study, different concentrations of PET and r-PET polymers were prepared in a TFA:DCM solvent mixture. Viscosity, electrical conductivity, surface tension, and pH parameters of the solutions tested and their suitability for needle electrospinning are evaluated. Nanofibers with varied flow rates and needle-to-collector distances were produced using solutions. The statistical variation of the average fiber diameter (AFD) of the produced nanofibers was calculated. Statistical modeling and experimental data compatibility were determined to be high as 99.21%. As a result, the concentration observed increased the AFD for both polymer solutions. While the increase in flow rate led to an expansion of the AFD distribution, the change in needle tip–collector distance did not have a significant effect on the AFD.