In this paper, polyethylene terephthalate(PET) and polypropylene (PP) non-wovens were modified by a dielectric barrier discharge in air, helium and argon at medium pressure(5.0kPa). The helium and argon discharges contained a fraction of air smaller than 0.1%. Surface analysis and characterization were performed using X-ray photoelectron spectroscopy, liquid absorptive capacity measurements and scanning electron microscopy (SEM). The non-wovens, modified in air, helium and argon, showed a significant increase in liquid absorptive capacity due to the incorporation of oxygen-containing groups, such as C-O, O-C=O and C=O. It was shown that an air plasma was more efficient in incorporating oxygen functionalities than an argon plasma, which was more efficient than a helium plasma, SEM pictures of the plasma-treated non wovens showed that the hydrophilicity of the non wovens could be increased to a saturation value with out causing physical degradation of the surface. The ageing behavior of the plasma-treated textiles after storage in air was also studied. It was shown that during the ageing process, the induced oxygen-containing groups re-orientated into the bulk of the material. This ageing effect was the smallest for the argon-plasma treated non-wovensm followed by the helium-plasma treated non-wovens, while the air-plasma treated non-wovens showed the largest ageing effect.