A plant for the continuous production of rolls of plastic stretch film starting from granules of one or more polymeric plastic materials, said plant comprising, in sequence, the following units: an extrusion unit of the cast extrusion type, in monoextrusion, comprising a flat extrusion die and at least one extruder (2,3) positioned upstream of said flat extrusion die, to form a melt of said polymeric plastic materials, a solidification unit of said melt comprising at least one chill-roll with a continuous surface, positioned immediately downstream of said flat extrusion die so as to solidify said melt, by cooling, to obtain said stretch film, one or more winding units of the stretch film into rolls and discharging of said rolls produced, wherein at least one of the extruders (2,3) of said polymeric plastic materials is a twin-screw extruder, said twin-screw extruder supplying the respective melt of polymeric plastic material with a pressure, in correspondence with the outlet mouth, which is such as to fill the parts of said plant positioned immediately downstream of said twin-screw extruder, wherein said pressure is such as to continuously feed said flat extrusion die and a respective gear pump, positioned downstream of said twin-screw extruder and upstream of said extrusion die, characterized in that in said twin-screw extruder each screw is composed of three distinct sections (a), b), c)), wherein a first section (a)) is dedicated to transporting the material, a second section (b)) is dedicated to mixing and a third section ((c)) is destined for compressing and pumping the polymeric plastic materials, wherein said screws are composed of elements with threadings (20, 30, 40) and mixing elements (60, 70), wherein said twin-screw extruder is provided with a final metering section of the melt of said respective polymeric plastic material wherein the free volume between the cylinder and the profile of the screws of said twin-screw extruder that occupy said section decreases towards the outlet mouth of said twin-screw extruder since the diameter of the threadings and cylinder remain constant along said section L and then the decreasing of the screw pitch in said section ensures that the free volume between the cylinder and the screws decreases gradually towards the outlet, so as to generate a pressure at the outlet mouth of said twin-screw extruder which is such as to fill said parts of the plant positioned immediately downstream of said twin-screw extruder. an extrusion unit of the cast extrusion type, in monoextrusion, comprising a flat extrusion die and at least one extruder (2,3) positioned upstream of said flat extrusion die, to form a melt of said polymeric plastic materials, a solidification unit of said melt comprising at least one chill-roll with a continuous surface, positioned immediately downstream of said flat extrusion die so as to solidify said melt, by cooling, to obtain said stretch film, one or more winding units of the stretch film into rolls and discharging of said rolls produced, wherein at least one of the extruders (2,3) of said polymeric plastic materials is a twin-screw extruder, said twin-screw extruder supplying the respective melt of polymeric plastic material with a pressure, in correspondence with the outlet mouth, which is such as to fill the parts of said plant positioned immediately downstream of said twin-screw extruder, wherein said pressure is such as to continuously feed said flat extrusion die and a respective gear pump, positioned downstream of said twin-screw extruder and upstream of said extrusion die, characterized in that in said twin-screw extruder each screw is composed of three distinct sections (a), b), c)), wherein a first section (a)) is dedicated to transporting the material, a second section (b)) is dedicated to mixing and a third section ((c)) is destined for compressing and pumping the polymeric plastic materials, wherein said screws are composed of elements with threadings (20, 30, 40) and mixing elements (60, 70), wherein said twin-screw extruder is provided with a final metering section of the melt of said respective polymeric plastic material wherein the free volume between the cylinder and the profile of the screws of said twin-screw extruder that occupy said section decreases towards the outlet mouth of said twin-screw extruder since the diameter of the threadings and cylinder remain constant along said section L and then the decreasing of the screw pitch in said section ensures that the free volume between the cylinder and the screws decreases gradually towards the outlet, so as to generate a pressure at the outlet mouth of said twin-screw extruder which is such as to fill said parts of the plant positioned immediately downstream of said twin-screw extruder.