Nonwoven polyester (PET) fabrics have been extensively studied for various applications. However, the nonwoven PET fabrics have poor wettability. In this work, nonwoven PET fabrics were impregnated in a stable and transparent alumina sol that was prepared by the hydrolysis of aluminium isopropoxide using the sol–gel technique. The Al2O3 particles were coated on nonwoven PET fabrics after the rolling-drying process. The surface morphology of modified nonwoven PET fabrics was characterized by scanning electronic microscopy (SEM) and atomic force microscopy (AFM). The SEM and AFM observations revealed the formation of the Al2O3 particles on the fiber surface. The Al2O3 coating was also
confirmed by Fourier transform infrared (FTIR). The mechanical properties of the coated nonwoven PET fabrics were investigated using a tensile strength test, and the results showed that the mechanical properties were improved after surface sol–gel coating. The effect of Al2O3 on the wetting behavior of the fabric was also significantly improved.