A system comprising: (1) a grinding unit configured to receive and grind recycled PET bottles into a group of polymer flakes comprising up to about ten percent colored polymer flakes and balance substantially clear polymer flakes; (2) a washing unit configured to wash the group of polymer flakes; and (3) an extruder configured to extrude material in a plurality of different extrusion streams. The extruder may be further configured to: (1) receive a concentrate-polymer mixture comprising a mixture of the polymer flakes and a color concentrate; (2) melt the concentrate-polymer mixture to produce a polymer melt; (3) reduce a pressure within the extruder; and (4) pass the polymer melt through the extruder so that the polymer melt is divided into the plurality of extrusion streams. The system may then filter the polymer melt through at least one filter and form the polymer melt into bulked continuous carpet filament.

A system comprising: (1) a grinding unit configured to receive and grind recycled PET bottles into a group of polymer flakes comprising up to about ten percent colored polymer flakes and balance substantially clear polymer flakes; (2) a washing unit configured to wash the group of polymer flakes; and (3) an extruder configured to extrude material in a plurality of different extrusion streams. The extruder may be further configured to: (1) receive a concentrate-polymer mixture comprising a mixture of the polymer flakes and a color concentrate; (2) melt the concentrate-polymer mixture to produce a polymer melt; (3) reduce a pressure within the extruder; and (4) pass the polymer melt through the extruder so that the polymer melt is divided into the plurality of extrusion streams. The system may then filter the polymer melt through at least one filter and form the polymer melt into bulked continuous carpet filament.

A method for manufacturing a cylindrical honeycomb fired body including: preparing a cylindrical honeycomb formed body; obtaining a cylindrical honeycomb dried body by drying the cylindrical honeycomb formed body; calculating predetermined parameters (E.sub.AVE1, E.sub.AVE2, E.sub.AVE3 and E.sub.AVE4) from average values of distance between a center of gravity position O and an outer peripheral contour in a plurality of predetermined angle ranges; specifying a minimum value of the predetermined parameters; obtaining a cylindrical honeycomb fired body by placing the cylindrical honeycomb dried body on a shelf plate and firing it while passing it through a continuous firing furnace, such that the direction in which the cells of the cylindrical honeycomb dried body extend vertically, and a particular location on the outer peripheral side surface determined according to the minimum value is positioned at the front.

A method for extruding a recycled polymer from an impure extrudable material comprises injecting a non-solvent in a liquid state into an apparatus and mixing substantially homogeneously the non-solvent with the impure extrudable material, thereby forming a dispersion of the non-solvent with the impure extrudable material. The impurities are output in a gaseous state from the apparatus.

A method for extruding a recycled polymer from an impure extrudable material comprises injecting a non-solvent in a liquid state into an apparatus and mixing substantially homogeneously the non-solvent with the impure extrudable material, thereby forming a dispersion of the non-solvent with the impure extrudable material. The impurities are output in a gaseous state from the apparatus.

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.

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.

Provided is a tube comprising a tetrafluoroethylene/fluoroalkyl vinyl ether copolymer, wherein the tube inner surface has a surface roughness Ra of 5 nm or less measured by atomic force microscopy (AFM) with an evaluation length set to 3 m, and the tube has an amount of metals eluted from the tube inner surface of 0.30 ng/cm.sup.2 or less.