Extruders machines for wire and cable, automotive profiles and medical pipes; extruder machine parts, namely, pipes, cylinders and barrels, straight or cross head extrusion heads and accessories for extruders, namely head supports, collar clamps, screws and barrels; gas injection and gas measuring system sold as a single unit comprised of gas booster, gas flow controller and fittings for all kind of extruders; special extrusion screws for extruders and polymers