the invention provides a bendable thermoplastic reinforcement for a profiled seal or profiled molding of a vehicle , such a profiled element including same and a method for producing the reinforcement . the reinforcement of substantially u - shaped cross section , has a central portion and two arms , each arm having over its length a series of limbs separated from one another by slots . over at least one part of the length of the reinforcement , each limb has laterally an asymmetrical geometry and an area greater than that of each adjacent slot . the reinforcement is produced by extrusion of a thermoplastic material via a die of u - shaped profile formed between an extruder head and a receiving member for the material being discharged from the head which is provided with a hollow cavity designed to form directly said central portion , the slots and limbs , so that the extruded material progressively covers the receiving member .