An extrusion die for extruding a synthetic material film according to a direction of extrusion, the extrusion die including: - a feed-in orifice configured to feed the extrusion die with a molten synthetic material, - a collector connected to the feed-in orifice and extending according to a direction of extension corresponding to the width of the synthetic material film to be extruded, - an outlet slot which extends substantially parallel to the direction of extension and which is connected to the collector such that the molten synthetic material introduced into the collector is expelled through the outlet slot, - a first worm screw having a first central longitudinal axis and a second worm screw having a second central longitudinal axis, the first and second worm screws (11, 12) extending transversely to the direction of extrusion and delimiting at least one flow passage configured to enable a flow of the molten synthetic material from the collector towards the outlet slot, characterized in that the extrusion die further includes: - a rotational drive device configured to drive the first worm screw in rotation about the first central longitudinal axis and according to a first sense of rotation and to drive the second worm screw in rotation about the second central longitudinal axis and according to a second sense of rotation which is opposite to the first sense of rotation, the first worm screw being configured to displace at least a first portion of the molten synthetic material flowing through the at least one flow passage according to a direction of displacement which is substantially parallel to the direction of extension and in a first sense of displacement, and the second worm screw being configured to displace at least a second portion of the molten synthetic material flowing through the at least one flow passage according to the direction of displacement and in a second sense of displacement which is opposite to the first sense of displacement. - a feed-in orifice configured to feed the extrusion die with a molten synthetic material, - a collector connected to the feed-in orifice and extending according to a direction of extension corresponding to the width of the synthetic material film to be extruded, - an outlet slot which extends substantially parallel to the direction of extension and which is connected to the collector such that the molten synthetic material introduced into the collector is expelled through the outlet slot, - a first worm screw having a first central longitudinal axis and a second worm screw having a second central longitudinal axis, the first and second worm screws (11, 12) extending transversely to the direction of extrusion and delimiting at least one flow passage configured to enable a flow of the molten synthetic material from the collector towards the outlet slot, - a rotational drive device configured to drive the first worm screw in rotation about the first central longitudinal axis and according to a first sense of rotation and to drive the second worm screw in rotation about the second central longitudinal axis and according to a second sense of rotation which is opposite to the first sense of rotation, the first worm screw being configured to displace at least a first portion of the molten synthetic material flowing through the at least one flow passage according to a direction of displacement which is substantially parallel to the direction of extension and in a first sense of displacement, and the second worm screw being configured to displace at least a second portion of the molten synthetic material flowing through the at least one flow passage according to the direction of displacement and in a second sense of displacement which is opposite to the first sense of displacement.