For the production of polymers in which there are fillers with particle sizes below 10 m incorporated and homogeneously distributed, a polymer starting material is input into a twin-screw extruder and is melted there to give a melt. In a conveying and mixing section, a suspension, which is formed of the fillers and of a carrier liquid, is injected into the melt. The melt viscosity is reduced by injection of the carrier liquid in the conveying and mixing section in that a cleavable polycondensate is used as polymer and low-molecular-weight cleavage product arising during the polycondensation is used as carrier liquid, and therefore the molten polymer is at least to some extent depolymerized within the conveying and mixing section. That the mixture, which is formed of the melt whose viscosity is reduced by cleavage, of the remainder of the carrier liquid and of the fillers, is homogenized.

A kneading apparatus includes a processor and an extruder. The extruder includes a screw. The screw includes a screw main body. A conveyance portion, a barrier portion, and a path are provided at places of the screw main body. In at least one of the places, the path is provided inside the screw main body and includes an entrance and an exit. The raw materials, pressure on which is increased by the barrier portion, flow in from the entrance. The raw materials flowing in from the entrance flow through the path toward the exit. The exit is positioned to be remote from the entrance in an axial direction. A method of using the kneading apparatus includes continuously melting and mixing materials in the processor, using the melted materials as the raw materials, and continuously discharging kneaded materials produced by kneading the raw materials with the screw in the extruder.

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.

Provided is a method for producing a carbon fiber composite material having high strength and elasticity and containing recycled carbon fibers. When a raw material is transported along the outer circumferential surface of a screw main body 37 having a passage 88 therein, the transport of the raw material is restricted by a barrier portion 82 provided on the outer circumferential surface, a shearing force is applied to the raw material by the screw main body 37, and a stretching force is applied to the raw material by passing the raw material from the inlet 91 of the passage 88 provided on the outer circumferential surface to the outlet 92 of the passage 88, thereby shortening a fiber length of the recycled carbon fibers and obtaining a carbon fiber composite material having good strength and elasticity and containing 50-70 wt % of recycled carbon fibers well dispersed therein.

A production device for melt-blown non-woven fabric, with which a high molecular weight polymer can be reduced in molecular weight by applying a shear force to the high molecular weight polymer without adding an additive such as a peroxide that promotes thermal decomposition reaction, and a low molecular weight polymer can be efficiently produced. The low molecular weight polymer and the melt-blown non-woven fabric are produced using a continuous high shearing device that applies a shear force to the high molecular weight polymer serving as a raw material by rotation of a screw body 37 to reduce the molecular weight of the high molecular weight polymer so as to obtain a low molecular weight polymer, and cools the low molecular weight polymer by passing the low molecular weight polymer through a passage 88 arranged in the axial direction inside the screw body 37.