摘要 |
A cutter hub and blade assembly for an underwater pelletizer in which molten polymer is extruded as strands through orifices in a die plate. The cutter hub is rotatably driven and includes cutter blades mounted at a steep angle on the cutter hub and move along the face of the die plate to cut the extruded strands into pellets. The cutter blade support angle on the cutter arms is 60°-79°, preferably about 72° to about 76° and most preferably about 75°. The blade cutting edge is beveled or angled at about 40° to about 50° and preferably about 45° to the opposed planar surfaces of the blade. The included angle between the blade cutting edge and the die face is at least about 20°. The inclination of the cutter blade support angle in combination with the blade cutting edge angle in accordance with the invention provides a clean cut of the pellets and enables faster blade grinding when seating new blades to the die face. The steep blade inclination also enables a larger number of cutter blades to be supported from a cutter hub and reduces "tracking" of the blade cutting edge toward the cutter hub center as the blade edges wear down.
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