SYSTEMS AND METHODS FOR MANUFACTURING BULKED CONTINUOUS FILAMENT

• US 20190105827A1
• Filed: 12/07/2018
• Published: 04/11/2019
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Aladdin Manufacturing Corporation (Mohawk Industries Incorporated)
• Original Assignee: Mohawk Industries Incorporated
• Inventors: Clark, Thomas R.
• Granted Patent: US 10,647,046 B2
• Time in Patent Office: Days
• 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 2013/005 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 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 2948/92514 Pressure
• CPC Class Codes: B29C 2948/92838 Raw material pre-treatment, e.g. drying or cleaning
• 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 48/0022 combined with cutting
• CPC Class Codes: B29C 48/02 Small extruding apparatus, e.g. handheld, toy or laboratory extruders
• 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 48/267 : Intermediate treatments, e.g. relaxation, annealing or decompression step for the melt B29C48/76 takes precedence
• 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 48/404 : the screws having non-intermeshing parts
• 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 48/69 : Filters or screens for the moulding material
• CPC Class Codes: B29C 48/70 : comprising means for dividing, distributing and recombining melt flows
• 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 flakes through a PET crystallizer; (E) passing the group of flakes through an MRS extruder while maintaining the pressure within the MRS portion of the MRS extruder below about 18 millibars; (F) passing the resulting polymer melt through at least one filter having a micron rating of less than about 50 microns; and (G) 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 of recycled PET;

(B) providing a PET crystallizer;

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

(D) at least partially melting the plurality of flakes into a polymer melt;

(E) providing a multi-rotating screw (MRS) extruder comprising;

an MRS Section comprising;

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;

a first single-screw extruder section comprising a first single extruder screw for melting the plurality of flakes of recycled PET to form a polymer melt and feeding the polymer melt into the MRS section;

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

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 25 millibars as the polymer melt passes through the MRS Section;

(F) using the vacuum to reduce a pressure within the MRS Section to below about 25 millibars;

(G) after the step of passing the plurality of flakes through the PET crystallizer and while maintaining the pressure within the MRS Section below about 25 millibars, passing the polymer melt through the MRS Section so that at least a portion of the polymer melt passes through each respective extruder barrel; and

(H) after the step of passing the polymer melt through the MRS extruder, forming the polymer melt into bulked continuous carpet filament.

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

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

4. The method of claim 3, wherein washing the plurality of flakes of recycled PET in the heated caustic bath comprises washing the plurality of flakes of recycled PET in the heated caustic bath to about 190 degrees Fahrenheit.

5. The method of claim 1, wherein washing the plurality of flakes of recycled PET comprises washing the plurality of flakes of 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 1, further comprising, before the step of washing the plurality of flakes, grinding a plurality of recycled PET bottles into the plurality of flakes of recycled PET.

7. The method of claim 6, wherein washing the plurality of flakes of recycled PET comprises using aqueous density separation to separate remnants of bottle caps from the plurality of recycled PET bottles from the plurality of flakes of recycled PET.

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

(A) providing a PET crystallizer;

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

(C) at least partially melting the plurality of flakes into a polymer melt;

(D) providing a multi-rotating screw (MRS) extruder comprising;

an MRS Section comprising;

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;

a first single-screw extruder section comprising a first single extruder screw for melting the plurality of flakes of recycled PET to form a polymer melt and feeding the polymer melt into the MRS section;

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

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 25 millibars as the polymer melt passes through the MRS Section;

(E) using the vacuum to reduce a pressure within the MRS Section to below about 25 millibars;

(F) after the step of passing the plurality of flakes through the PET crystallizer and while maintaining the pressure within the MRS Section below about 25 millibars, passing the polymer melt through the MRS Section so that at least a portion of the polymer melt passes through each respective extruder barrel; and

(G) after the step of passing the polymer melt through the MRS extruder, forming the polymer melt into bulked continuous carpet filament from 100% recycled PET.

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

10. 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 of recycled PET.

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

12. The method of claim 8, wherein the crystallizer comprises:

a hopper screw configured to feed the plurality of flakes of recycled PET into the crystallizer; and

a blower configured to blow hot air over the plurality of flakes of recycled PET as the plurality of flakes of recycled PET pass through the crystallizer.

13. The method of claim 8, wherein the crystallizer is configured to maintain a temperature of between about 140 degrees Celsius and about 180 degrees Celsius within the crystallizer.

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

(A) providing a PET crystallizer;

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

(C) at least partially melting the plurality of flakes into a polymer melt;

(D) providing a multi-rotating screw (MRS) extruder comprising;

an MRS Section comprising;

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;

a first single-screw extruder section comprising a first single extruder screw for melting the plurality of flakes of recycled PET to form a polymer melt and feeding the polymer melt into the MRS section;

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

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 25 millibars as the polymer melt passes through the MRS Section;

(E) using the vacuum to reduce a pressure within the MRS Section to below about 25 millibars;

(F) after the step of passing the plurality of flakes through the PET crystallizer and while maintaining the pressure within the MRS Section below about 25 millibars, passing the polymer melt through the MRS Section so that at least a portion of the polymer melt passes through each respective extruder barrel;

(G) after passing the polymer melt through the MRS Section, filtering the polymer melt through at least one filter; and

(H) after the step of passing the polymer melt through the MRS extruder and the at least one filter, forming the polymer melt into bulked continuous carpet filament.

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

16. The method of claim 15, wherein washing the plurality of flakes of recycled PET comprises washing the plurality of flakes of recycled PET to remove at least a portion of one or more contaminants from a surface of the plurality of flakes.

17. The method of claim 15, further comprising, before the step of washing the plurality of flakes, grinding a plurality of recycled PET bottles into the plurality of flakes of 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 14, 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.

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