Systems for manufacturing bulked continuous carpet filament from polymer, where the systems are configured for: (1) melting polymer (e.g., derived from post-consumer PET bottles) to create a first single stream of polymer melt; (2) separating the first single stream of polymer melt into multiple streams of polymer melt; (3) exposing the multiple streams of polymer melt to a pressure of between about 0 millibars and about 5 millibars; (4) allowing the multiple streams of polymer melt to fall into a receiving section of a melt processing unit; (5) recombining the multiple streams of polymer melt into a second single stream of polymer melt; and (6) providing the second single stream of polymer melt to one or more spinning machines that are configured to form the second single stream of polymer melt into bulked continuous carpet filament.