Systems and methods for manufacturing bulked continuous filament

• US 10,493,660 B2
• Filed: 12/30/2016
• Issued: 12/03/2019
• 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): Soohoo, Tony G
• Application Number:
  US15/396,143
• Publication Number:
  US 20170106566A1
• Time in Patent Office: 1,068 Days
• 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 7/486 with screws surrounded by a casing provided with grooves or cavities
• CPC Class Codes: B29B 7/726 Measuring properties of mixture, e.g. temperature or density B29B7/724 takes precedence
• 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 48/145 : at a venting 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 48/765 : in the extruder apparatus
• 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: 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 1.5 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. An apparatus for at least partially removing impurities from a recycled polymer comprising:

a multi-rotating screw (MRS) extruder comprising;

an MRS Section comprising;

a plurality of satellite screws, each of the plurality of satellite screws being 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;

a first single-screw extruder section comprising a first single extruder screw for feeding the recycled polymer into the MRS section; and

a second single-screw extruder section comprising a second single extruder screw for transporting the recycled polymer away from the MRS section;

a vacuum pump in communication with the MRS section that is adapted to maintain a pressure within the MRS Section below a pressure of about 5 millibars as the recycled polymer passes through the MRS Section; and

a controller that operates the vacuum pump to maintain the pressure within the MRS Section below the pressure of about 5 millibars while the MRS extruder is extruding the recycled polymer, wherein;

the apparatus further comprises a viscosity sensor that measures a melt viscosity of the recycled polymer after the recycled polymer has passed through the MRS Section; and

the controller further operates in a feedback control loop with the viscosity sensor to operate the vacuum pump to further reduce the pressure within the MRS Section in response to using the viscosity sensor to measure an intrinsic viscosity of the recycled polymer that is below a predetermined level.

2. The apparatus of claim 1, wherein the plurality of satellite screws comprise at least six satellite screws.

3. The apparatus of claim 2, wherein:

the MRS Section comprises a drum that is adapted to rotate about the main axis;

the drum defines a respective screw barrel for each of the plurality of satellite screws, each of the respective screw barrels being substantially parallel to the main axis; and

each of the plurality of satellite screws is rotatably mounted within its respective screw barrel.

4. The apparatus of claim 1, wherein:

the MRS Section comprises a vacuum attachment portion defining an opening in a housing of the MRS Section; and

the vacuum pump is coupled to the vacuum attachment portion and is in communication with the interior of the MRS section via the opening.

5. The apparatus of claim 1, further comprising a filtration system that includes at least one filter.

6. The apparatus of claim 5, wherein the at least one filter comprises at least one filter selected from a group consisting of:

i. at least one 40 micron screen filter; and

ii. at least one 25 micron screen filter.

7. The apparatus of claim 1, wherein the vacuum pump comprises at least one jet vacuum pump.

8. The apparatus of claim 1, wherein the vacuum pump comprises at least one mechanical lobe vacuum pump.

9. The apparatus of claim 1, wherein the predetermined level is about 0.8 dL/g.

10. A multi-screw extruder for at least partially removing impurities from a polymer melt, wherein the multi-screw extruder comprises:

an extruder housing;

at least four satellite screw disposed within the extruder housing, wherein each of the at least four satellite screws is mounted to rotate about its respective central axis;

a pressure regulation system that is adapted to maintain a pressure within the extruder housing below a pressure of about 5 millibars as the polymer melt passes through the multi-screw extruder;

a controller that operates the pressure regulation system to maintain the pressure within the extruder housing below the pressure of about 5 millibars while the multi-screw extruder is extruding the polymer melt;

a viscosity sensor that measures a melt viscosity of the polymer melt after the polymer melt has passed through the extruder housing; and

the controller further operates in a feedback control loop with the viscosity sensor to operate the pressure regulation system to further reduce the pressure within the extruder housing in response to using the viscosity sensor to measure an intrinsic viscosity of the polymer melt that is below a predetermined level.

11. The multi-screw extruder of claim 10, wherein:

the multi-screw extruder further comprises a satellite screw drum that houses the at least four satellite screws; and

the satellite screw drum is adapted to orbitally rotate the at least four satellite screws about a main axis as each of the at least four satellite screws rotate about its respective central axis while the polymer melt passes through the multi-screw extruder; and

the main axis is substantially parallel to each respective central axis.

12. The multi-screw extruder of claim 11, wherein each of the at least four satellite screws is adapted to rotate in a direction that is the same as a direction in which the satellite screw drum is adapted to rotate.

13. The multi-screw extruder of claim 11, wherein each of the at least four satellite screws is adapted to rotate in a direction that is opposite to a direction in which the satellite screw drum is adapted to rotate.

14. A multi-screw extruder for use in extruding a polymer melt, the extruder comprising:

a first satellite screw extruder, the first satellite screw extruder comprising a first satellite screw that is mounted to rotate about a central axis of the first satellite screw;

a second satellite screw extruder, the second satellite screw extruder comprising a second satellite screw that is mounted to rotate about a central axis of the second satellite screw;

a pressure regulation system that is adapted to maintain a pressure within the first and second satellite screw extruders below a pressure of about 5 millibars as the polymer melt passes through the first and second screw extruders; and

a controller that operates the pressure regulation system to maintain the pressure within the first and second satellite screw extruders below the pressure of about 5 millibars while the multi-screw extruder is extruding the polymer melt.

15. The multi-screw extruder of claim 14, wherein the extruder comprises a satellite screw extruder support system that is adapted to orbitally rotate the first and second satellite screws about a main axis as the polymer melt passes through the first and second screw extruders, the main axis being substantially parallel to both:

(1) the central axis of the first satellite screw; and

(2) the central axis of the second satellite screw.

16. The multi-screw extruder of claim 15, wherein:

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

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

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

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

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

17. The multi-screw extruder of claim 16, wherein:

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

the pressure regulation system is adapted to maintain a pressure within the third satellite screw extruder below a pressure of about 5 millibars as the polymer melt passes through the third screw extruder;

the satellite screw extruder support system is adapted to orbitally rotate the third satellite screw about the main axis as the polymer melt passes through the third screw extruder; and

the main axis is substantially parallel to the central axis of the third satellite screw.

18. The multi-screw extruder of claim 17, wherein:

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

the pressure regulation system is adapted to maintain a pressure within the fourth satellite screw extruder below a pressure of about 5 millibars as the polymer melt passes through the fourth screw extruder;

the satellite screw extruder support system is adapted to orbitally rotate the fourth satellite screw about the main axis as the polymer melt passes through the fourth screw extruder; and

the main axis is substantially parallel to the central axis of the fourth satellite screw.

19. The multi-screw extruder of claim 18, further comprising a filtration system that includes at least one filter selected from a group consisting of:

i. at least one 40 micron screen filter; and

ii. at least one 25 micron screen filter.