PVC flooring production line

A polyvinyl chloride (PVC) flooring production line, comprising a loading system, an internal-mixing extrusion device, a calendering lamination device, a cooling device, a tractor, and a cutter that are arranged sequentially along a material conveying direction, wherein

• a film unwinding mechanism is provided on a top of the calendering lamination device;
• a delivery track is provided along the calendering lamination device, the cooling device, the tractor, and the cutter;
• the internal-mixing extrusion device comprises an internal mixing mechanism, an extrusion mechanism, and a hopper;
• the internal mixing mechanism comprises a mixing chamber;
• the mixing chamber comprises a rear end provided with a first feed port, and a front end provided with a first discharge port;
• a rotor is provided in the mixing chamber along a front-rear direction;
• the extrusion mechanism is located below the internal mixing mechanism;
• the extrusion mechanism comprises an extruding chamber;
• the extruding chamber comprises a rear end provided with a second feed port, and a front end provided with a mold;
• a screw is provided in the extruding chamber along the front-rear direction;
• and
• the hopper is connected between the first discharge port and the second feed port,
• wherein the rotor is a double-kneading structure;
• the rotor comprises a rotor shaft;
• and a material conveying segment, a first mixing segment, a first helical segment, a second mixing segment, and a first discharge segment are arranged sequentially on the rotor shaft, and
• wherein a second helical segment is further provided between the second mixing segment and the first discharge segment directly adjacent to the first discharge segment, wherein the second helical segment has a shorter length along the front-rear direction than the material conveying segment and the first helical segment and has a shorter distance between helical windings than the material conveying segment and the first helical segment.