Methods for manufacturing bulked continuous filament

• US 10,654,211 B2
• Filed: 12/14/2018
• Issued: 05/19/2020
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Aladdin Manufacturing Corporation (Mohawk Industries Incorporated)
• Original Assignee: Aladdin Manufacturing Corp. (China) (Mohawk Industries Incorporated)
• Inventors: Clark, Thomas R.
• Primary Examiner(s): Tentoni, Leo B
• Application Number:
  US16/220,905
• Publication Number:
  US 20190118450A1
• Time in Patent Office: 522 Days
• Field of Search: 264101, 264102, 264169, 2641761, 26421121, 26421122, 26421123
• CPC Class Codes: B29B 13/06 by drying B29B13/08 takes precedence ; drying moulded articles or half products B29C37/0092
• CPC Class Codes: B29B 17/0026 by agglomeration or compacting
• CPC Class Codes: B29B 17/02 Separating plastics from other materials
• CPC Class Codes: B29B 17/0412 to large particles, e.g. beads, granules, flakes, slices
• CPC Class Codes: B29B 2013/002 Extracting undesirable residual components, e.g. solvents, unreacted monomers, from material to be moulded
• CPC Class Codes: B29B 2013/005 Degassing undesirable residual components, e.g. gases, unreacted monomers, from material to be moulded
• CPC Class Codes: B29B 2017/0015 Washing, rinsing
• CPC Class Codes: B29B 2017/0279 Optical identification, e.g. cameras or spectroscopy
• CPC Class Codes: B29B 2017/0289 Washing the materials in liquids
• CPC Class Codes: B29B 7/485 with three or more shafts provided with screws
• CPC Class Codes: B29B 7/86 for working at sub- or superatmospheric pressure B01F33/70 takes precedence
• CPC Class Codes: B29C 2948/922 Viscosity; Melt flow index [MFI]; Molecular weight
• CPC Class Codes: B29C 2948/92514 Pressure
• CPC Class Codes: B29C 2948/92857 Extrusion unit
• CPC Class Codes: B29C 48/0022 combined with cutting
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/144 at the plasticising zone
• CPC Class Codes: B29C 48/255 Flow control means, e.g. valves flow dividers B29C48/695
• CPC Class Codes: B29C 48/2552 provided in the feeding, melting, plasticising or pumping zone, e.g. screw, barrel, gear-pump or ram
• CPC Class Codes: B29C 48/38 : using two or more serially arranged screws in the same barrel
• CPC Class Codes: B29C 48/385 : using two or more serially arranged screws in separate barrels
• CPC Class Codes: B29C 48/40 : using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
• CPC Class Codes: B29C 48/425 : using three or more screws serially arranged screws B29C48/38, B29C48/385
• CPC Class Codes: B29C 48/43 : Ring extruders
• CPC Class Codes: B29C 48/435 : Sub-screws
• CPC Class Codes: B29C 48/44 : Planetary screws
• CPC Class Codes: B29C 48/525 : Conical screws
• CPC Class Codes: B29C 48/766 : in screw extruders
• CPC Class Codes: B29C 48/767 : through a degassing opening of a barrel
• CPC Class Codes: B29C 48/92 : Measuring, controlling or regulating
• CPC Class Codes: B29D 99/0078 : Producing filamentary materials
• CPC Class Codes: B29K 2067/003 : PET, i.e. poylethylene terephthalate
• CPC Class Codes: B29K 2105/26 : Scrap or recycled material
• CPC Class Codes: B29L 2031/731 : Filamentary material, i.e. comprised of a single element, e.g. filaments, strands, threads, fibres cables B29L2031/707
• CPC Class Codes: C08J 11/04 : of polymers
• CPC Class Codes: C08J 2367/02 : Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: D01D 1/103 : De-aerating
• CPC Class Codes: D01D 1/106 : Filtering
• CPC Class Codes: D01D 5/08 : Melt spinning methods D01D5/0023 takes precedence
• CPC Class Codes: D01F 6/62 : from polyesters
• CPC Class Codes: D02G 3/24 : Bulked yarns or threads, e.g. formed from staple fibre components with different relaxation characteristics
• CPC Class Codes: Y02P 20/143 : the feedstock being recycled material, e.g. plastics
• CPC Class Codes: Y02W 30/62 : Plastics recycling; Rubber recycling

Abstract

A method of manufacturing bulked continuous carpet filament which, in various embodiments, comprises: (A) grinding recycled PET bottles into a group of flakes; (B) washing the flakes; (C) identifying and removing impurities, including impure flakes, from the group of flakes; (D) passing the group of flakes through an expanded surface area extruder while maintaining a pressure within the expanded surface area extruder below about 25 millibars; (E) passing the resulting polymer melt through at least one filter having a micron rating of less than about 50 microns; and (F) forming the recycled polymer into bulked continuous carpet filament that consists essentially of recycled PET.

Claims

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

(A) washing a plurality of flakes comprising recycled PET;

(B) providing a PET crystallizer;

(C) after the step of washing the plurality of flakes comprising recycled PET, passing at least a portion of the plurality of flakes comprising recycled PET through the PET crystallizer to at least partially dry a surface of the plurality of flakes comprising recycled PET;

(D) providing an expanded surface area extruder, wherein the expanded surface area extruder defines an expanded surface area extruder inlet and an expanded surface area extruder outlet and comprises;

a plurality of satellite screws, each of the plurality of satellite screws being at least partially housed within a respective extruder barrel and mounted to rotate about its respective central axis; and

a satellite screw extruder support system that is adapted to orbitally rotate each of the plurality of satellite screws about a main axis as each of the plurality of satellite screws rotate about its respective central axis, the main axis being substantially parallel to each respective central axis;

(E) providing a pressure regulation system configured to reduce a pressure within at least a portion of the expanded surface area extruder below about 25 mbar;

(F) providing a spinning machine defining a spinning machine inlet, wherein the spinning machine inlet is operatively coupled to the expanded surface area extruder outlet;

(G) using the pressure regulation system to reduce the pressure within the at least a portion of the expanded surface area extruder below about 25 mbar;

(H) after passing the plurality of flakes comprising recycled PET through the PET crystallizer, passing the plurality of flakes comprising PET flakes through the expanded surface area extruder via the expanded surface area extruder inlet to at least partially melt the plurality of flakes to form a polymer melt such that at least a portion of the polymer melt passes through each the respective satellite screw; and

(I) substantially immediately after passing the plurality of flakes through the expanded surface area extruder, using the spinning machine to form the polymer melt into bulked continuous carpet filament.

2. The method of claim 1, wherein washing the plurality of flakes comprises mixing the plurality of flakes in a series of wash tanks.

3. The method of claim 1, wherein washing the plurality of flakes comprises washing the plurality of flakes in a heated caustic bath.

4. The method of claim 3, wherein the heated caustic bath is maintained at a concentration of between about 0.6% sodium hydroxide and about 1.2% sodium hydroxide.

5. The method of claim 1, wherein washing the plurality of flakes comprising recycled PET comprises washing the plurality of flakes comprising recycled PET to remove at least a portion of one or more contaminants from a surface of the plurality of flakes.

6. The method of claim 5, wherein:

the plurality of flakes comprise;

a first plurality of flakes that consist essentially of PET; and

a second plurality of flakes that do not consist essentially of PET;

the method further comprises, after the step of washing the plurality of flakes;

(i) scanning the washed group of flakes to identify the second plurality of flakes; and

(ii) separating the second plurality of flakes from the first plurality of flakes; and

passing at least a portion of the plurality of flakes comprising recycled PET through the PET crystallizer comprises passing the first plurality of flakes through the PET crystallizer.

7. The method of claim 1, further comprising grinding a plurality of recycled PET bottles into the plurality of flakes comprising recycled PET.

8. A method of manufacturing bulked continuous carpet filament, the method comprising:

(A) providing a PET crystallizer;

(B) passing a plurality of flakes comprising recycled PET through the PET crystallizer to at least partially dry a surface of the plurality of flakes comprising recycled PET;

(C) providing an expanded surface area extruder, wherein the expanded surface area extruder defines an expanded surface area extruder inlet and an expanded surface area extruder outlet and comprises;

a plurality of satellite screws, each of the plurality of satellite screws being at least partially housed within a respective extruder barrel and mounted to rotate about its respective central axis; and

a satellite screw extruder support system that is adapted to orbitally rotate each of the plurality of satellite screws about a main axis as each of the plurality of satellite screws rotate about its respective central axis, the main axis being substantially parallel to each respective central axis;

(D) providing a pressure regulation system configured to reduce a pressure within at least a portion of the expanded surface area extruder below about 25 mbar;

(E) providing a spinning machine defining a spinning machine inlet, wherein the spinning machine inlet is operatively coupled to the expanded surface area extruder outlet;

(F) using the pressure regulation system to reduce the pressure within the at least a portion of the expanded surface area extruder below about 25 mbar;

(G) after passing the plurality of flakes comprising recycled PET through the PET crystallizer, passing the plurality of flakes comprising PET flakes through the expanded surface area extruder via the expanded surface area extruder inlet to at least partially melt the plurality of flakes to form a polymer melt such that at least a portion of the polymer melt passes through each the respective satellite screw; and

(H) substantially immediately after passing the plurality of flakes through the expanded surface area extruder, using the spinning machine to form the polymer melt into bulked continuous carpet filament.

9. The method of claim 8, further comprising, before the step of passing the plurality of flakes comprising recycled PET through the PET crystallizer, washing the plurality of flakes.

10. The method of claim 9, wherein washing the plurality of flakes comprising recycled PET comprises washing the plurality of flakes comprising recycled PET to remove at least a portion of one or more contaminants from a surface of the plurality of flakes.

11. The method of claim 9, further comprising, before the step of washing the plurality of flakes, grinding a plurality of recycled PET bottles into the plurality of flakes comprising recycled PET.

12. The method of claim 11, wherein washing the plurality of flakes comprises using aqueous density separation to separate remnants of bottle caps from the plurality of recycled PET bottles from the plurality of flakes comprising recycled PET.

13. The method of claim 8, wherein the method comprises manufacturing bulked continuous carpet filament from 100% recycled PET.

14. A method of manufacturing bulked continuous carpet filament, the method comprising:

(A) providing a PET crystallizer;

(B) passing a plurality of flakes comprising recycled PET through the PET crystallizer to at least partially dry a surface of the plurality of flakes comprising recycled PET;

(C) providing an expanded surface area extruder, wherein the expanded surface area extruder defines an expanded surface area extruder inlet and an expanded surface area extruder outlet and comprises;

a plurality of satellite screws, each of the plurality of satellite screws being at least partially housed within a respective extruder barrel and mounted to rotate about its respective central axis; and

a satellite screw extruder support system that is adapted to orbitally rotate each of the plurality of satellite screws about a main axis as each of the plurality of satellite screws rotate about its respective central axis, the main axis being substantially parallel to each respective central axis;

(D) providing a pressure regulation system configured to reduce a pressure within at least a portion of the expanded surface area extruder below about 25 mbar;

(E) providing a spinning machine defining a spinning machine inlet, wherein the spinning machine inlet is operatively coupled to the expanded surface area extruder outlet;

(F) using the pressure regulation system to reduce the pressure within the at least a portion of the expanded surface area extruder below about 25 mbar;

(G) after passing the plurality of flakes comprising recycled PET through the PET crystallizer, passing the plurality of flakes comprising PET flakes through the expanded surface area extruder via the expanded surface area extruder inlet to at least partially melt the plurality of flakes to form a polymer melt such that at least a portion of the polymer melt passes through each the respective satellite screw;

(H) after passing the plurality of flakes through the expanded surface area extruder, filtering the polymer melt through at least one filter; and

(I) substantially immediately after passing the plurality of flakes through the expanded surface area extruder and filtering the polymer melt through the at least one filter, using the spinning machine to form the polymer melt into bulked continuous carpet filament.

15. The method of claim 14, wherein the at least one filter has a micron rating of less than about 50 microns.

16. The method of claim 14, further comprising, before the step of passing the plurality of flakes comprising recycled PET through the PET crystallizer, washing the plurality of flakes.

17. The method of claim 16, further comprising, before the step of washing the plurality of flakes, grinding a plurality of recycled PET bottles into the plurality of flakes comprising recycled PET.

18. The method of claim 14, wherein the method comprises manufacturing bulked continuous carpet filament from 100% recycled PET.

19. The method of claim 18, wherein manufacturing bulked continuous carpet filament from 100% recycled PET substantially immediately after extruding the recycled PET comprises spinning the polymer melt into bulked continuous carpet filament without substantially cooling the polymer melt.

20. The method of claim 14, wherein the at least one filter comprises a 40 micron screen filter followed by a 25 micron screen filter.