Systems and methods for manufacturing bulked continuous filament

1. A method of manufacturing bulked continuous carpet filament, said method comprising:

(A) providing a multi-screw extruder that comprises:

(i) a first satellite screw extruder, said first satellite screw extruder comprising a first satellite screw that is mounted to rotate about a central axis of said first satellite screw;

(ii) a second satellite screw extruder, said second satellite screw extruder comprising a second satellite screw that is mounted to rotate about a central axis of said second satellite screw; and

(iii) a pressure regulation system that is adapted to maintain a pressure within said first and second satellite screw extruders between about 0 millibars and about 1.8 millibars;

(B) using said pressure regulation system to reduce a pressure within said first and second satellite screw extruders to between about 0 millibars and about 1.8 millibars;

(C) while maintaining said pressure within said first and second satellite screw extruders between about 0 millibars and about 1.8 millibars, passing a melt comprising recycled polymer through said multi-screw extruder so that: (1) a first portion of said melt passes through said first satellite screw extruder, and (2) a second portion of said melt passes through said second satellite screw extruder; and

(D) after said step of passing said melt of recycled polymer through said multi-screw extruder, forming said recycled polymer into bulked continuous carpet filament.

2. The method of claim 1 , wherein said multi-screw extruder comprises a satellite screw extruder support system that is adapted to rotate said first and second satellite screws about a main axis, said main axis being substantially parallel to both: (a) said central axis of said first satellite screw; and (b) said central axis of said second satellite screw.

3. The method of claim 2 , wherein said step of passing said melt of recycled polymer through said multi-screw extruder occurs while said first and second satellite screw extruders are orbitally rotating about said main axis.

4. The method of claim 1 , wherein said step of using said pressure regulation system to reduce a pressure within said first and second satellite screw extruders to between about 0 millibars and about 1.8 millibars comprises using said pressure regulation system to reduce a pressure of said first and second satellite screw extruders to between about 0 millibars and about 1.0 millibar.

5. The method of claim 4 , wherein said pressure regulation system comprises a jet vacuum pump.

6. The method of claim 2 , wherein:

said satellite screw extruder support system comprises a drum that is adapted to rotate about said main axis;

said drum defines a first screw barrel having a central axis that is substantially parallel to said main axis;

said drum defines a second screw barrel having a central axis that is substantially parallel to said main axis;

said first satellite screw is rotatably mounted within said first screw barrel; and

said second satellite screw is rotatably mounted within said second screw barrel.

7. The method of claim 2 , wherein

said extruder comprises a third satellite screw extruder, said third satellite screw extruder comprising a third satellite screw that is mounted to rotate about a central axis of said third satellite screw;

said pressure regulation system is adapted to maintain a pressure within said third satellite screw extruder between a pressure of about 0 millibars and about 2 millibars;

said satellite screw extruder support system is adapted to rotate said third satellite screw about said main axis;

said main axis is substantially parallel to said central axis of said third satellite screw; and

said step of passing said melt of recycled polymer through said multi-screw extruder comprises passing a third portion of said melt through said third satellite screw extruder.

8. The method of claim 1 , wherein:

said extruder is a first extruder; and

said method further comprises:

passing a plurality of flakes of recycled PET through a second extruder; and

while passing said plurality of flakes through said second extruder, using said second extruder to heat said plurality of flakes to a temperature that is sufficient to at least substantially melt said plurality of flakes to form said polymer melt.

9. The method of claim 8 , wherein said method further comprises:

before said step of passing said plurality of flakes through said second extruder:

washing said plurality of flakes;

scanning said washed plurality of flakes to identify any of said plurality of flakes that comprise material other than PET; and

removing at least one of said identified flakes that comprise material other than PET.

10. The method of claim 1 , wherein, after said step of passing said melt of recycled polymer through said multi-screw extruder, said polymer melt has an intrinsic viscosity of between about 0.79 dL/g and about 1.00 dL/g.

11. The method of claim 1 , further comprising, after said step of passing said melt of recycled polymer through said multi-screw extruder, passing said polymer melt though at least one filter having a micron rating of less than about 25 microns.

12. The method of claim 1 , wherein said step of forming said recycled polymer into bulked continuous carpet filament comprises spinning said polymer melt to form said bulked continuous carpet filament.

13. The method of claim 1 , further comprising, before said step of forming said recycled polymer into bulked continuous carpet filament:

using a viscosity sensor to determine whether an intrinsic viscosity of at least a portion of recycled polymer is within a pre-determined range; and

in response to determining said intrinsic viscosity is not within a predetermined range, adjusting said pressure regulation system to lower said internal pressure of said extruder.

14. A method of manufacturing carpet filament comprising the steps of:

(A) washing a group of polymer flakes to remove at least a portion of one or more contaminants from a surface of said flakes, said group of flakes comprising a first plurality of flakes that consist essentially of PET and a second plurality of flakes that do not consist essentially of PET;

(B) after said step of washing said first plurality of flakes:

(i) scanning said washed group of flakes to identify said second plurality of flakes,

(ii) separating said second plurality of flakes from said first plurality of flakes;

(C) melting said second plurality of flakes to produce a polymer melt;

(D) providing an extruder that extrudes material in a plurality of different extrusion streams;

(E) reducing a pressure within said extruder to between about 0 millibars and about 1.5 millibars;

(F) while maintaining said pressure within said extruder between about 0 millibars and about 1.5 millibars, passing said polymer melt through said extruder so that said polymer melt is divided into a plurality of extrusion streams, each having a pressure between about 0 millibars and about 1.5 millibars;

(G) after passing said polymer melt through said extruder, filtering said polymer melt through at least one filter; and

(H) after passing said polymer melt through said filter, forming said recycled polymer into bulked continuous carpet filament.

15. The method of claim 14 , wherein said extruder comprises:

(A) a first satellite screw extruder, said first satellite screw extruder comprising a first satellite screw that is mounted to rotate about a central axis of said first satellite screw;

(B) a second satellite screw extruder, said second satellite screw extruder comprising a second satellite screw that is mounted to rotate about a central axis of said second satellite screw;

(C) a pressure regulation system that is adapted to maintain a pressure within said first and second satellite screw extruders between a pressure of about 0 millibars and about 1.5 millibars as said polymer melt passes through said first and second screw extruders; and

(D) a satellite screw extruder support system that is adapted to orbitally rotate said first and second satellite screws about a main axis as said polymer melt passes through said first and second screw extruders, said main axis being substantially parallel to both: (1) said central axis of said first satellite screw; and (2) said central axis of said second satellite screw.

16. The method of claim 15 , wherein said pressure regulation system is configured to lower said pressure within said extruder to between about 0 millibars and about 1.3 millibars.

17. The method of claim 15 , wherein said at least one filter comprises:

a first filter having a micron rating of less than about 50 microns; and

a second filter having a micron rating of less than about 30 microns.