Abstract
Different techniques used for the mass coloration of polyester fibers are discussed in this article. Dope-dyed fibers have been produced starting from PET bottle wastes. Dope dyeing has been carried out both by the incorporation of pigments during drying before melt extrusion and by masterbatch addition. Fibers produced using different pigments and at different add-ons have been evaluated for color fastness properties and loss of mechanical properties due to dope addition. It has been shown that fibers having excellent fastness properties with little loss in mechanical properties could be obtained by either of these techniques. Fibers produced by recycling PET bottle wastes have been compared with those obtained by recycling polyester fiber wastes and virgin fiber grade polyesters melt spun under identical conditions. It has been demonstrated that bottle wastes yield fibers having properties equivalent to those of virgin polyester but probably cost similar as fiber wastes. Molded automotive carpets developed from recycled fibers from PET bottle wastes have shown excellent mechanical and fastness properties. It is inferred that using dope-dyed fibers based on PET bottle wastes in automotive applications may ensure a high benefit to cost ratio.