WIRE AND CABLE SHEATH EXTRUSION METHOD AND POSITIVE DISPLACEMENT EXTRUDER

摘要

A wire and cable sheath extrusion method and a positive displacement extruder. The wire and cable sheath extrusion method comprises: using three geometric shaped members to create a closed space; using two continuously rotating members to continuously change the volume of the closed space; when the volume increases, feeding molten sheath plastic; and when the volume decreases, pressing, exhausting air, plasticizing and extruding the molten sheath plastic to wrap the periphery of a wire or cable to form a sheath. The positive displacement extruder comprises a feeding cylinder (1), an extrusion part (2), an injection nozzle (3) and an extrusion die (4) that are communicated sequentially. The extrusion part comprises a stator (21), and a drive rotor (22) and a driven rotor (23) arranged in the inner cavity of the stator (21) and engaged with each other. The stator (21) and the two rotors (22, 23) create a closed space. The two rotors (22, 23) rotate to continuously change the volume. The wire and cable sheath extrusion method and the positive displacement extruder can increase the density of the sheath, improve the strength and toughness thereof, and shorten the process of thermal mechanical action.