Patent ID: 8727762

Claim:
A die plate for resin granulation, comprising: a plurality of extrusion nozzle holes disposed in a plate main body, for extruding a molten resin; a plurality of heating channels for heating the extrusion nozzle holes; and an outer annular heating passage and an inner annular heating passage for communicating the heating channels with one another, wherein the extrusion nozzle holes between the heating channels are disposed along a crossing direction (E) which crosses a circumferential direction of the plate main body, wherein the die plate further comprises: first to n-th regions (A to n) positioned every 360/n degrees in the plate main body, where n=4, 6 or 8; nozzle hole groups disposed in each of the first to n-th regions (A to n) and positioned between the heating channels; outer walls and inner walls respectively disposed in the outer annular heating passage and the inner annular heating passage in the first to n-th regions (A to n); a plurality of heating medium outlets positioned between the first to n-th regions (A to n) and connected to the inner annular heating passage between the inner walls, the heating medium outlets being led from the inner annular heating passage, between the outer walls in the outer annular heating passage and outwardly of the outer annular heating passage; and a plurality of heating medium inlets disposed between the outer walls in each of the first to n-th regions (A to n), wherein a heating medium flows through the heating channels only once so that the temperature of the heating medium is lowered below a predetermined temperature, and then the heating medium flows into the heating medium outlets of the plate main body, wherein the heating medium outlets are communicated with a heating source apparatus so that the heating medium can be heated to the predetermined temperature and returned to the heating medium inlets of the plate main body, and wherein the heating medium supplied through the heating medium inlets passes through the heating channels between the inner walls, and flows out through the heating medium outlets to the outside.