Methods for manufacturing bulked continuous filament

• US 10,639,818 B2
• Filed: 07/20/2018
• Issued: 05/05/2020
• 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:
  US16/041,442
• Publication Number:
  US 20180326622A1
• Time in Patent Office: 655 Days
• Field of Search: 264 401, 264101, 264102, 264169, 26421122, 26421123, 264918, 264920, 209659
• CPC Class Codes: B01D 29/0095 Flat filtering elements B01D25/12, B01D25/26 take precedence
• CPC Class Codes: B07C 2501/0036 Sorting out metallic particles
• CPC Class Codes: B29B 17/00 Recovery of plastics or other constituents of waste material containing plastics; volume reduction of waste plastics, e.g. by mechanical compacting or melting disposal of solid waste B09B; chemical recovery C08J11/00
• CPC Class Codes: B29B 17/02 Separating plastics from other materials
• 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 2017/0203 Separating plastics from plastics
• CPC Class Codes: B29B 2017/0224 Screens, sieves
• CPC Class Codes: B29B 7/427 with independently driven screws rotating about the same axis, e.g. oscillating axially; with axially oscillating screws B29B7/423 takes precedence
• CPC Class Codes: B29B 7/485 with three or more shafts provided with screws
• CPC Class Codes: B29B 7/7466 Combinations of similar mixers
• CPC Class Codes: B29C 2791/003 Making articles of indefinite length B29C53/48 takes precedence
• CPC Class Codes: B29C 2791/006 Using vacuum
• CPC Class Codes: B29C 2948/922 Viscosity; Melt flow index [MFI]; Molecular weight
• CPC Class Codes: B29C 2948/9238 Feeding, melting, plasticising or pumping zones, e.g. the melt itself
• CPC Class Codes: B29C 2948/9239 Screw or gear
• CPC Class Codes: B29C 2948/92514 Pressure
• CPC Class Codes: B29C 2948/92876 Feeding, melting, plasticising or pumping zones, e.g. the melt itself
• CPC Class Codes: B29C 37/006 Degassing moulding material or draining off gas during moulding venting means in moulds B29C33/10
• 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 48/70 : comprising means for dividing, distributing and recombining melt flows
• 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 2105/0067 : Melt
• CPC Class Codes: B29K 2105/26 : Scrap or recycled material
• CPC Class Codes: C08J 11/04 : of polymers
• CPC Class Codes: C08J 11/06 : without chemical reactions
• 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 5/00 : Formation of filaments, threads, or the like
• CPC Class Codes: D01D 5/08 : Melt spinning methods D01D5/0023 takes precedence
• CPC Class Codes: D01F 6/62 : from polyesters
• CPC Class Codes: D10B 2503/04 : Floor or wall coverings; Carpets
• CPC Class Codes: H05K 999/99 : dummy group
• CPC Class Codes: Y02P 20/143 : the feedstock being recycled material, e.g. plastics
• CPC Class Codes: Y02W 30/62 : Plastics recycling; Rubber recycling
• CPC Class Codes: Y02W 30/64 : Paper 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 MRS extruder while maintaining the pressure within the MRS portion of the MRS extruder below about 5 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 from post-consumer material, the method comprising:

providing a means for preparing flakes of PET polymer from the post-consumer material for melting and purifying;

providing a means for melting and purifying the flakes of PET polymer into a polymer melt at a pressure between about 0.5 millibars and about 5 millibars, wherein providing the means for melting and purifying the flakes of PET polymer into the polymer melt at the pressure between about 0.5 millibars and about 5 millibars comprises;

routing wet flakes of PET polymer directly into an extruder;

providing a means for melting the wet flakes of PET polymer into the polymer melt within the extruder;

providing a means for reducing the pressure within the extruder to between about 0.5 millibars and about 5 millibars; and

providing a means for filtering the polymer melt to remove contaminants; and

providing a means for transforming the polymer melt into a bulked continuous carpet filament, wherein providing the means for melting the wet flakes of PET polymer into the polymer melt within the extruder comprises;

providing a multi-screw extruder configured to receive the wet flakes of PET polymer and creating the polymer melt within the multi-screw extruder, the multi-screw extruder comprising;

a multi-screw extruder housing that defines at least four satellite screw barrels;

at least four satellite screws each mounted within a respective one of the at least four satellite screw barrels and each mounted to rotate about a respective central axis of each of the at least four satellite screws; and

a means for maintaining a pressure within each of the respective satellite screw barrels between about 0.5 millibars and about 5 millibars.

2. The method of claim 1, wherein providing the means for preparing the flakes of PET polymer from the post-consumer material comprises:

providing a means for sorting the post-consumer material by size;

providing a means for removing metal from the post-consumer material;

providing a means for sorting the post-consumer material by color;

providing a means for removing labels from the post-consumer material; and

providing a means for washing the flakes of PET polymer.

3. The method of claim 2, wherein providing the means for washing the flakes of PET polymer comprises washing the flakes in a heated caustic bath maintained at a concentration of between about 0.6% and about 1.2% sodium hydroxide.

4. The method of claim 2, further comprising:

after providing the means for washing the flakes of PET polymer, providing a means for detecting the presence of contaminants; and

providing a means for removing a quantity of contaminants sufficient to achieve a level of non-PET flakes that is less than 25 ppm.

5. The method of claim 4, further comprising providing a means for removing surface water from the flakes of PET polymer prior to providing the means for melting and purifying the flakes of PET polymer.

6. The method of claim 1, wherein the means for maintaining the pressure within each of the respective satellite screw barrels comprises a means for maintaining the pressure within each of the respective satellite screw barrels between about 0.5 millibars and about 1 millibar.

7. The method of claim 1, wherein the means for maintaining the pressure within each of the respective satellite screw barrels comprises a plurality of mechanical lobe vacuum pumps arranged in series and coupled to the at least four satellite screw barrels.

8. The method of claim 1, wherein the means for maintaining the pressure within each of the respective satellite screw barrels comprises a jet vacuum pump coupled to the at least four satellite screw barrels.

9. The method of claim 1, wherein each of the at least four satellite screw barrels are about thirty percent open to an outer chamber of the multi-screw extruder that encompasses the at least four satellite screw barrels.

10. The method of claim 1, wherein the multi-screw extruder comprises eight satellite screws mounted within a respective one of eight satellite screw barrels.

11. The method of claim 1, wherein the at least four satellite screw barrels are arranged within a single screw drum that is configured to rotate about a central axis, and wherein each of the at least four satellite screws is adapted to rotate around a respective satellite screw axis that is substantially parallel to the central axis of the single screw drum.

12. The method of claim 11, wherein each of the at least four satellite screws is configured to rotate at a different rate than the single screw drum.

13. The method of claim 11, wherein each of the at least four satellite screws is configured to rotate in a different direction than the single screw drum.

14. The method of claim 1, further comprising providing a means for maintaining an intrinsic viscosity of the polymer melt through the multi-screw extruder between about 0.79 dL/g and about 1.00 dL/g.

15. The method of claim 14, wherein the means for maintaining the intrinsic viscosity of the polymer melt through the multi-screw extruder comprises

a viscosity sensor coupled to the multi-screw extruder and operative to measure an intrinsic viscosity of the polymer melt;

and

in response to detecting the intrinsic viscosity of the polymer melt below a predetermined viscosity level, the sensor operative to

initiate a discard of a portion of the polymer melt that is below the predetermined viscosity level, or

initiate a pressure reduction within the multi-screw extruder.

16. A method of manufacturing bulked continuous carpet filament from post-consumer material, the method comprising:

providing a means for preparing flakes of PET polymer from the post-consumer material for melting and purifying;

providing a multi-screw extruder having at least four satellite screws each mounted in parallel within a respective one of at least four satellite screw barrels and each mounted to rotate about a respective central axis of each of the at least four satellite screw screws, the multi-screw extruder configured to receive the flakes of PET polymer at an input and provide a polymer melt at an output;

providing a pressure regulation system that is adapted to maintain a pressure within each of the respective satellite screw barrels between about 0.5 millibars and about 5 millibars; and

providing a means for transforming the polymer melt into a bulked continuous carpet filament.

17. The method of claim 16, wherein providing the means for preparing the flakes of PET polymer from the post-consumer material comprises:

providing a means for sorting the post-consumer material by size;

providing a means for removing metal from the post-consumer material;

providing a means for sorting the post-consumer material by color;

providing a means for removing labels from the post-consumer material; and

providing a means for washing the flakes of PET polymer.

18. The method of claim 16, wherein providing the pressure regulation system that is adapted to maintain the pressure within each of the respective satellite screw barrels comprises providing the pressure regulation system that is adapted to maintain the pressure within each of the respective satellite screw barrels between about 0.5 millibars and about 1 millibar.

19. The method of claim 16, wherein the pressure regulation system comprises a plurality of mechanical lobe vacuum pumps arranged in series and coupled to the at least four satellite screw barrels.

20. The method of claim 16, wherein the pressure regulation system comprises a jet vacuum pump coupled to the at least four satellite screw barrels.

21. The method of claim 16, wherein the multi-screw extruder comprises eight satellite screws mounted within a respective one of eight satellite screw barrels.

22. The method of claim 16, wherein each of the at least four satellite screw barrels are about thirty percent open to an outer chamber of the multi-screw extruder that encompasses the at least four satellite screw barrels.

23. The method of claim 16, wherein the at least four satellite screw barrels are arranged within a single screw drum that is configured to rotate about a central axis, and wherein each of the at least four satellite screws is adapted to rotate around a respective satellite screw axis that is substantially parallel to the central axis of the single screw drum.

24. The method of claim 23, wherein each of the at least four satellite screws is configured to rotate at a different rate than the single screw drum.

25. The method of claim 23, wherein each of the at least four satellite screws is configured to rotate in a different direction than the single screw drum.

26. The method of claim 16, further comprising providing a means for maintaining an intrinsic viscosity of the polymer melt through the multi-screw extruder between about 0.79 dL/g and about 1.00 dL/g.

27. The method of claim 26, wherein the means for maintaining the intrinsic viscosity of the polymer melt through the multi-screw extruder comprises

a viscosity sensor coupled to the multi-screw extruder and operative to measure an intrinsic viscosity of the polymer melt;

and

in response to detecting the intrinsic viscosity of the polymer melt below a predetermined viscosity level, the sensor operative to

initiate a discard of a portion of the polymer melt that is below the predetermined viscosity level, or

initiate a pressure reduction within the multi-screw extruder.

28. A method of manufacturing bulked continuous carpet filament from post-consumer material, the method comprising:

providing a means for sorting the post-consumer material by size;

providing a means for removing metal from the post-consumer material;

providing a means for sorting the post-consumer material by color;

providing a means for removing labels from the post-consumer material;

providing a means for washing the flakes of PET polymer to create wet flakes of PET polymer;

routing the wet flakes of PET polymer directly into an extruder;

providing a means for melting the wet flakes of PET polymer into a polymer melt within the extruder, wherein providing the means for melting the wet flakes of PET polymer into the polymer melt within the extruder comprises;

providing a multi-screw extruder configured to receive the wet flakes of PET polymer and creating the polymer melt within the multi-screw extruder, the multi-screw extruder comprising;

a multi-screw extruder housing that defines at least four satellite screw barrels;

at least four satellite screws each mounted within a respective one of the at least four satellite screw barrels and each mounted to rotate about a respective central axis of each of the at least four satellite screws; and

a means for maintaining a pressure within each of the respective satellite screw barrels between about 0.5 millibars and about 5 millibars;

providing a means for maintaining the pressure within the extruder to between about 0.5 millibars and about 5 millibars;

providing a means for filtering the polymer melt to remove contaminants and create a purified molten polymer; and

providing a means for transforming the purified molten polymer into a bulked continuous carpet filament.