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.

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 MRS extruder while maintaining the pressure within the MRS portion of the MRS extruder 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.

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.

Methods for extrusion of polyolefins (110) that utilize melt temperature to control molecular weight and also reduce gels. Disclosed herein is an example method for controlling polymer chain scission in an extrusion system (100), comprising: melting a polyolefin resin (110) in extruder (102) at a first melt temperature to form a first melt (112); passing the first melt (112) through a screen pack (106); forming the first melt 112) into a first polyolefin product (116, 118); melting additional polyolefin resin (110) of the same grade in the extruder (102) at a second melt temperature to form a second melt (112), wherein the second melt temperature differs from the first melt temperature by 5 C. or more to control chain scission in the extruder (102); passing the second melt (112) through the screen pack (106); and forming the second melt (112) into a second polyolefin product (116, 118).

An extruder includes a cylinder 2 and a die 5 attached to the cylinder 2. The die 5 has a resin flow path portion 22 to which a molten resin is supplied from the cylinder 2 and a hole 21 which is connected to the resin flow path portion 22 and from which the molten resin is discharged. The extruder further includes a pressure measurement unit 31 configured to measure a pressure of the molten resin in the cylinder 2 or the die 5 and a calculation unit configured to calculate a viscosity of the molten resin based on a measured value of the pressure measurement unit 31.

A method of manufacturing bulked continuous carpet filament from recycled polymer. In various embodiments, the method includes: (1) reducing recycled polymer material into polymer flakes; (2) cleansing the polymer flakes; (3) melting the flakes into a polymer melt; (4) removing water and contaminants from the polymer melt by dividing the polymer melt into a plurality of polymer streams and exposing those streams to pressures below 5 millibars; (5) recombining the streams; and (6) using the resulting purified polymer to produce bulked continuous carpet filament.

A system for manufacturing bulked continuous carpet filament that is adapted for providing a polymer melt and dividing the polymer melt into a plurality of streams (e.g., at least six or eight streams) to increase a surface area of the polymer melt. The plurality of streams is then exposed to a pressure that is below approximately 5 millibars. The streams are then recombined into a single polymer stream and formed into bulked continuous carpet filament. In various embodiments, an extruder, such as a multi-screw extruder, is used to divide the polymer melt into the plurality of streams.

A method for manufacturing bulked continuous carpet filament, the method comprising: (1) reducing a chamber pressure within a chamber to below about 5 millibars; (2) after reducing the chamber pressure to below about 5 millibars, providing a polymer melt to the chamber; (3) separating the polymer melt into at least eight streams; (4) while the at least eight streams of the polymer melt are within the chamber, exposing the at least eight streams of the polymer melt to the chamber pressure of below about 5 millibars; (5) after exposing the at least eight streams of the polymer melt to the chamber pressure of below about 5 millibars, recombining the at least eight streams into a single polymer stream; and (6) forming polymer from the single polymer stream into bulked continuous carpet filament.

A method of manufacturing bulked continuous carpet filament that includes providing a polymer melt and separating the polymer melt from the extruder into at least eight streams. The multiple streams are exposed to a chamber pressure within a chamber that is below approximately 25 millibars, or another predetermined pressure. The streams are recombined into a single polymer stream. Polymer from the polymer stream is then formed into bulked continuous carpet filament.

Rheological measurement systems for use with systems including pressurized polymer melts and/or other viscous materials are described. In one embodiment, a rheometer is connected to an associated system with a bent, curved, or bendable tube to permit the rheometer to measure rheological properties in locations where the rheometer could not otherwise be located due to the presence of obstructions. Embodiments including rigid straight tubes for connecting a rheometer to an associated system are also described. In another embodiment, a flow-through rheometer is connected to an industry standard ?-20 thermowell aperture that is typically used for attaching temperature and pressure probes to a vessel containing a viscous material such as an extruder or injection molding system. The rheological measurement systems described can have improved tube resistance and thermal strength.