Methods of making pigmented filaments

The present invention relates generally to the field of thermoplastic polymeric materials containing one or more additives. In preferred exemplary embodiments, the present invention relates to synthetic filament additives (e.g., colorants) and to methods for incorporating such additives in melt flows of filament-forming thermoplastic polymeric materials prior to melt-spinning to form synthetic filaments therefrom. Polymeric compositions include a nonaqueous additive system having dispersant-coated pigments physically dispersed in a liquid nonaqueous polymeric carrier which may be added directly to a melt flow of a polymeric host material. The additive system employed in the polymeric systems is most preferably in the form of a particulate paste which can be added in metered amounts (dosed) to a melt flow of the polymeric host material prior to being spun into filaments. By providing a number of additive systems having a number of different additive attributes, and controllably dosing one or more into the melt flow of host polymeric material, shaped objects of the polymeric material (e.g., melt-spun filaments) having different additive attributes may be produced on a continuous basis without shutting down the shaping operation.