In one embodiment of the single screw extruder
In one embodiment of the present single screw extruder, the tiles are made of carbide or tungsten-carbide. In another preferred embodiment of the present twin screw extruder, the step of securing further comprises brazing, soldering, or gluing.
The present sheet production extruder, accordingly, provides a method of applying a plurality of tiles to a flighting crest of at least one thread of an extruder screw. A groove is formed along the crest. Each tile is then inserted into the groove, wherein the tiles are in a spaced-apart arrangement. The tiles are then secured into the groove. In one preferred embodiment of the present invention, the groove is formed in the extruder screw when the extruder screw threads is cast. In yet another preferred embodiment of the present invention, the groove is cut into the crest after the extruder screw has been cast. In yet another alternative embodiment of the present invention, the tiles are further ground to remove any protruding edges and to fit within the tolerances of an extruder barrel. Another alternative embodiment of the present invention, further comprises inserting a spacer into spaces between the tiles; and securing the spacers.
In another preferred embodiment of the present invention, plates of a wear-resistant material are secured to at least one leading edge of the extruder screw threads in a spaced-apart arrangement.
Additionally, the present invention also provides an apparatus for extruding. An extruding screw having at least one thread with a crest and having a groove formed therein is provided. Also, there are a plurality of tiles formed of a hardened materials secured within the groove in a spaced-apart arrangement. In an alternative embodiment of the present invention, the hardened material is carbide or tungsten-carbide. In another alternative embodiment of the present invention the tiles are secured by brazing, soldering, or gluing. In another preferred embodiment of the present twin screw extruder, spacers secured between the tiles.
Additionally, in yet another preferred embodiment of the present single screw extruder, a plurality of plates made of the hardened material are secured to the crest in a spaced-apart arrangement.