OVIDIU CONSTANDACHE, ANGELA CEREMPEI, RODICA MURESAN, IRINA CRINA ANCA SANDU, AUGUSTIN MURESAN, ION SANDU STUDY OF DYEING AND OBTAINING ANTIMICROBIAL EFFECTS OF VIRGIN AND RECYCLED POLYESTER FIBERS In this paper we studied the dyeing behaviour of polyester fibers from recycled polyester and virgin dyed with Foron brilliant rot SGL (CI Disperse Red 121). The amount of dye fixed recycled fiber is higher than that of virgin. Elemental analysis confirms a slight change in the carbon and oxygen content of recycled fiber compared to virgin. Thus the recycled polyester fiber carbon content is higher than virgin fiber in oxygen exchange is less. Dyed samples were treated with AgNO3 in order to confer antibacterial properties. The analyses SEM/EDAX have highlighted the presence of silver ions on the surface of fibers.