A center heated die plate for an underwater pelletizer radiates heat
outwardly to the extrusion orifices and die faces of the die plate
thereby maintaining the die plate and extrusion orifices at an elevated
temperature to obtain optimum flow of molten polymer through the
extrusion orifices. In one embodiment, a cylindrical heating coil is
placed in a hollow central core of the die plate and a plurality of
peripheral heating elements are inserted in radial recesses distributed
around an outer perimeter of the die plate to create an inner heat zone
and an outer heat zone which are separately controllable.