Abstract Improved die plate for underwater extrusion pelletizer apparatus and method for making, wherein the die plate, essentially integral, defines on its extrusion face a first recessed surface extending around the die plate, a serpentine recessed channel within and deeper than the first recessed surface and extending nearly around the die plate, and a shoulder surrounding the serpentine recessed channel adjacent the first recessed surface. A thin inlay member seats over the serpentine channel and against the shoulder in sealing relation to provide with the serpentine channel a sealed chamber adapted to conduct a heated fluid nearly around the die plate. The first recessed surface is filled to the surface level of the inlay member and the face of the die plate with a wear resistant coating material of harder material than the material of the inlay member and the die plate. The wear resistant coating does not cover the inlay member but rather extends to either side of the inlay member and is adapted to support the pellet shearing knives from causing undue wear to the softer material of the inlay member and die plate. A plurality of insert members each defining an extrusion orifice therethrough are inserted through openings centrally formed at spaced intervals through the serpentine-configurated inlay member and through the opposite face of the die plate and are sealingly secured at their junctures with the opposed faces of the die plate. Inlet and outlet passages extend into the die plate in communication with the sealed chamber and serve to introduce into and remove from the sealed chamber a fluid heating medium for circulation along the serpentine channel entirely around each of the insert members.
An improved underwater pelletizer die plate defiNing a first recessed surface within and extending around one face of the die plate, a serpentine recessed channel within and deeper than said first recessed surface, a shoulder surrounding said serpentine recessed channel adjacent the first recessed surface, an inlay member adapted to seal over said serpentine channel and against said shoulder in sealing relation to provide with the serpentine channel a sealed chamber in said die plate adapted to conduct a heated fluid substantially around the die plate, a coating adapted to resist wear and to fill said first recessed surface to the surface level of the inlay member and the face of the die plate; a plurality of insert members each defining an extrusion orifice therethrough and extending through the inlay member and into and through the die plate and terminating flush in sealing relation with the other face of the die plate and with the surface of the inlay member and centrally positioned in the serpentine channel and equally spaced from adjacent insert members along the serpentine chamber, each said insert member adapted to convey through said extrusion orifice extruded material; and means including inlet and outlet passages extending into the die plate and in communication with said serpentine sealed chamber by which a fluid heating medium may be introduced into said sealed chamber for circulation entirely around each of said insert members and be removed from said sealed chamber.
Claim 2
Dependent Claim
240 words
An improved underwater pelletizer die plate defiNing a first recessed surface within and extending around one face of the die plate, a serpentine recessed channel within and deeper than said first recessed surface, a shoulder surrounding said serpentine recessed channel adjacent the first recessed surface, an inlay member adapted to seal over said serpentine channel and against said shoulder in sealing relation to provide with the serpentine channel a sealed chamber in said die plate adapted to conduct a heated fluid substantially around the die plate, a coating adapted to resist wear and to fill said first recessed surface to the surface level of the inlay member and the face of the die plate; a plurality of insert members each defining an extrusion orifice therethrough and extending through the inlay member and into and through the die plate and terminating flush in sealing relation with the other face of the die plate and with the surface of the inlay member and centrally positioned in the serpentine channel and equally spaced from adjacent insert members along the serpentine chamber, each said insert member adapted to convey through said extrusion orifice extruded material; and means including inlet and outlet passages extending into the die plate and in communication with said serpentine sealed chamber by which a fluid heating medium may be introduced into said sealed chamber for circulation entirely around each of said insert members and be removed from said sealed chamber.
Claim 3
Dependent Claim
72 words
An improved underwater pelletizer die plate as defined in claim 1, and wherein each of said insert members defines an extrusion orifice that is of uniform internal diameter along that portion of the length of the insert member that is within the sealed serpentine chamber, and in the same portion also defines a reduced exterior diameter having a series of grooves formed within and extending around the surface of the insert member.