a method for controlling the viscoelastic properties of a polymer comprising the steps of feeding a polymer melt into a first and optional subsequent means for applying a strain rate , each means for applying a strain rate being underfed or overfed according to the relative volumetric flow rates into the out of each means for applying a strain rate . the method further comprises subjecting the polymer melt in the means for applying a strain rate to a total shear rate that comprises contributions selected from the group consisting of pressure flow through an orifice , rotational flow about an axis that is parallel to the direction of flow of the melt , vibration in the transverse or longitudinal direction relative to the flow direction of the melt , and any combination thereof . the flow profile history that the polymer melt is subjected to is controlled by the choice of first , optional second and optional subsequent volumetric flow rates , the temperatures of processing in the first , optional second and optional subsequent means for applying a strain rate , and the shear rates exerted by the pressure flow , rotational flow and vibration in each or any of the first , optional second and optional further means for applying a strain rate . there are optionally intermediary zones in between the first means for applying a strain rate and the optional second means for applying a strain rate or the optional second means for applying a strain rate and the optional subsequent means for applying a strain rate or both , and the temperature in the optional intermediary zones are optionally used for control of the flow profile history of the melt .