Methods for manufacturing bulked continuous filament from colored recycled PET

Patent metadata

Field	Value
Publication number	US-11007673-B2
Application number	US-201916537844-A
Country	US
Kind code	B2
Filing date	Aug 12, 2019
Priority date	May 31, 2012
Publication date	May 18, 2021
Grant date	May 18, 2021

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) adding one or more color concentrates to the flakes; (E) passing the group of flakes through an extrusion system while maintaining the pressure within the extrusion system below about 25 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.

First claim

What is claimed is:

1. A method of manufacturing bulked continuous carpet filament, the method comprising:
(A) providing an extrusion system that comprises:
(i) a first extruder;
(ii) a second extruder; and
(iii) a pressure regulation system that is adapted to maintain a pressure within the first and second extruders between about 0 millibars and about 5 millibars;

(B) using the pressure regulation system to reduce a pressure within the first and second extruders to between about 0 millibars and about 5 millibars;
(C) providing a plurality of polymer flakes, the plurality of polymer flakes comprising between about six percent and about ten percent colored recycled polyethylene terephthalate (PET) flakes and balance substantially clear recycled PET flakes;
(D) providing one or more color additives;
(E) adding the one or more color additives to the plurality of polymer flakes such that the resulting mixture comprises between about zero percent and about three percent of the one or more color additives by weight;
(F) while maintaining the pressure within the first and second extruders between about 0 millibars and about 5 millibars, passing the plurality of polymer flakes and the one or more color additives through the extrusion system to form a polymer melt so that: (1) a first portion of the polymer melt passes through the first extruder, and (2) a second portion of the polymer melt passes through the second extruder; and
(G) after the step of passing the polymer melt through the extrusion system, forming the recycled polymer into bulked continuous carpet filament.

2. The method of claim 1 , wherein the colored recycled PET flakes consist essentially of colored PET flakes derived from recycled PET bottles.

3. The method of claim 2 , wherein the colored recycled PET flakes comprise one or more types of PET flake selected from a group consisting of:
i. amber PET flake;
ii. blue PET flake; and
iii. green PET flake.

4. The method of claim 1 , further comprising:
providing a color sensor configured to determine a color of the polymer melt; and
substantially automatically adjusting an amount of the one or more color additives added to the plurality of polymer flakes based at least in part on the determined color of the polymer melt.

5. The method of claim 4 , wherein the plurality of polymer flakes comprises:
between about six percent and about ten percent colored recycled PET flakes by weight;
up to about six percent polytrimethylene terephthalate (PTT) by weight; and
balance substantially clear recycled PET flakes.

6. The method of claim 5 , wherein the plurality of polymer flakes comprises:
between about seven percent and about nine percent colored recycled PET flakes by weight;
between about five percent and about six percent PTT by weight; and
balance substantially clear recycled PET flakes.

7. The method of claim 1 , wherein the one or more color additives at least partially offset a coloration of the bulked continuous carpet filament from the colored recycled PET flakes.

8. The method of claim 1 , wherein the one or more color additives comprise a solution dye concentrate.

9. The method of claim 1 , wherein the extrusion system is one of a twin screw extruder, a multiple screw extruder, or a planetary extruder.

10. A method of manufacturing carpet filament from clear and colored recycled PET bottles comprising the steps of:
(A) providing a plurality of recycled PET bottles;
(B) grinding the plurality of recycled PET bottles into a group of polymer flakes, the group of polymer flakes comprising up to about ten percent colored polymer flakes and balance substantially clear polymer flakes;
(C) washing the group of polymer flakes;
(D) providing a color additive;
(E) mixing the color additive with the group of polymer flakes to form a color additive-polymer mixture comprising up to about three percent color additive by weight;
(F) melting the color additive-polymer mixture to produce a polymer melt;
(G) providing an extruder that extrudes material in a plurality of different extrusion streams;
(H) reducing a pressure within the extruder to between about 0 millibars and about 12 millibars;
(I) while maintaining the pressure within the extruder between about 0 millibars and about 12 millibars, passing the polymer melt through the extruder so that the polymer melt is divided into a plurality of extrusion streams, each having a pressure between about 0 millibars and about 12 millibars;
(J) after passing the polymer melt through the extruder, filtering the polymer melt through at least one filter; and
(K) after passing the polymer melt through the filter, forming the polymer melt into bulked continuous carpet filament.

11. The method of claim 10 , the method further comprising:
providing polytrimethylene terephthalate (PTT); and
adding the PTT to the color additive-polymer mixture, such that the color additive-polymer mixture comprises:
up to about three percent color additive by weight;
up to about six percent PTT by weight; and
balance the group of polymer flakes.

12. The method of claim 11 , wherein adding the PTT to the color additive-polymer mixture increases the dyeability of the resultant color additive-polymer mixture.

13. The method of claim 12 , the method further comprising adding the PTT to the color additive-polymer mixture, such that the color additive-polymer mixture comprises:
between about two percent and about three percent color additive by weight;
between about five percent and about six percent PTT by weight; and
balance the group of polymer flakes.

14. The method of claim 10 , the method further comprising:
providing one or more color sensors configured to determine a color of the polymer melt; and
substantially automatically adjusting an amount of the color additive added to the color additive-polymer mixture based at least in part on the determined color of the polymer melt.

15. The method of claim 14 , wherein the one or more color sensors comprise one or more color sensors selected from a group consisting of:
one or more cameras; and
one or more spectrographs.

16. The method of claim 10 , wherein the color additive at least partially masks a coloration of the bulked continuous carpet filament caused by the colored polymer flakes.

17. A method of manufacturing bulked continuous carpet filament, the method comprising:
(A) providing an extrusion system that comprises:
(i) a first extruder;
(ii) a second extruder;
(iii) a third extruder;
(iv) a fourth extruder; and
(v) a pressure regulation system that is adapted to maintain a pressure within the first, second, third, and fourth extruders between about 1 millibar and about 18 millibars;

(B) using the pressure regulation system to reduce a pressure within the first, second, third, and fourth extruders to between about 0 millibars and about 18 millibars;
(C) while maintaining the pressure within the first, second, third, and fourth extruders between about 1 millibar and about 18 millibars, passing a polymer melt through the extrusion system so that: (1) a first portion of the melt passes through the first extruder, (2) a second portion of the melt passes through the second extruder, (3) a third portion of the melt passes through the third extruder, and (4) a fourth portion of the melt passes through the fourth extruder, wherein:
the polymer melt comprises:
between about seven percent and about nine percent colored recycled PET by weight;
between about two percent and about three percent color additive by weight; and
balance rec

Assignees

• Aladdin Mfg Corp

Inventors

• Clark Thomas R

Classifications

• D01F6/92

  of polyesters · CPC title

• B29C48/43

  Ring extruders · CPC title

• D01D1/103

  De-aerating · CPC title

• B29C2948/92876

  Feeding, melting, plasticising or pumping zones, e.g. the melt itself · CPC title

• B29B2017/0015

  Washing, rinsing · CPC title