A method of manufacturing bulked continuous carpet filament, said method comprising: providing a first extruder, said first extruder comprising: a first extruder inlet and a first extruder outlet; and a pressure regulation system that is adapted to maintain a pressure within said first extruder below about 18 millibars; using said pressure regulation system to reduce a pressure within said first extruder to below about 18 millibars; while maintaining said pressure within said first extruder below about 18 millibars, passing a plurality of flakes of recycled PET through said first extruder via said first extruder inlet to at least partially melt said plurality of flakes into a polymer melt; providing at least one spinning machine comprising at least one spinning machine inlet, wherein said at least one spinning machine inlet is substantially directly coupled to said first extruder outlet; after said step of passing said polymer melt through said first extruder, substantially immediately forming said polymer melt into bulked continuous carpet filament using said at least one spinning machine, wherein said first extruder is a conical co-rotating twin screw extruder and comprises a first conical screw and a second conical screw, said method further comprising: providing a PET crystallizer; wherein the PET crystallizer comprises a housing, a hopper screw disposed at least partially within the housing, a stirring apparatus, one or more heating elements and one or more blowers configured to blow air over the flakes as the flakes pass through the crystallizer; and prior to passing said plurality of flakes of recycled PET through said first extruder, passing said plurality of flakes of recycled PET through said PET crystallizer to at least partially dry a surface of said plurality of flakes of recycled PET, wherein the one or more blowers are moving air substantially across a surface area of the flakes as the flakes pass through the crystallizer. providing a first extruder, said first extruder comprising: a first extruder inlet and a first extruder outlet; and a pressure regulation system that is adapted to maintain a pressure within said first extruder below about 18 millibars; a first extruder inlet and a first extruder outlet; and a pressure regulation system that is adapted to maintain a pressure within said first extruder below about 18 millibars; using said pressure regulation system to reduce a pressure within said first extruder to below about 18 millibars; while maintaining said pressure within said first extruder below about 18 millibars, passing a plurality of flakes of recycled PET through said first extruder via said first extruder inlet to at least partially melt said plurality of flakes into a polymer melt; providing at least one spinning machine comprising at least one spinning machine inlet, wherein said at least one spinning machine inlet is substantially directly coupled to said first extruder outlet; after said step of passing said polymer melt through said first extruder, substantially immediately forming said polymer melt into bulked continuous carpet filament using said at least one spinning machine, providing a PET crystallizer; wherein the PET crystallizer comprises a housing, a hopper screw disposed at least partially within the housing, a stirring apparatus, one or more heating elements and one or more blowers configured to blow air over the flakes as the flakes pass through the crystallizer; and prior to passing said plurality of flakes of recycled PET through said first extruder, passing said plurality of flakes of recycled PET through said PET crystallizer to at least partially dry a surface of said plurality of flakes of recycled PET, wherein the one or more blowers are moving air substantially across a surface area of the flakes as the flakes pass through the crystallizer.