A kneading disc for a single screw extruder
A kneading disc for a single screw extruder, the disc having a central longitudinal axis and comprising a kneading body of given width twin screw extruder, given material and having a region of maximum operating stress, and at least one wear-resistant insert placed fixedly in a form-fitting recess in said body of the disc in said region of maximum operating stress so as to be substantially surrounded by said given material of said kneading body, wherein the geometrical shape of said at least one insert has straight and mutually parallel outer surfaces and is placed in a correspondingly configured recess in said body of the kneading disc, said configured recess constituting said form-fitting recess, and wherein said at least one recess extends parallel to said central longitudinal axis and completely across said given width of said kneading body.
The sheet production extruder relates to a single screw extruder, and more particularly to the kneading discs in a screw extruder machine. More specifically, the invention relates to the provision of wear protection for those parts of the kneading disc particularly susceptible to wear and tear due to high stresses and high abrasive influences.
In the majority of cases, the kneading discs are used in multiple screw extruders having at least two shafts in such a way that they scrape each other clean during rotation. In order to maintain the effectiveness of this scraping and also to maintain the kneading action, the wear of the kneading edges must never be large and normally should not exceed at most a few millimeters. Accordingly, the length of the inserts is determined almost exclusively by the necessity for secure anchoring within the body of the kneading disc and not by the expected amount of wear.
It will be understood that the methods and inserts described in the FIGS. 1-4 and in FIGS. 10 and 11 can also be used to strengthen the outer surfaces or sides of the blades of helical kneading twin screw extruder.
It will be understood by those in the art that various changes may be made in the manner of embodying the single screw extruder without thereby departing from its spirit and scope.