Werner & Pfleiderer Gmbh

Gerhard Gnadig

Wilhelm Seufert

Fritz Przybylla

Albert Grimminger

Friedrich Schneider

Siegfried Kuklinski

Wolfgang Christen

A wear-protected workpiece of metal, particularly a perforated granulation plate for plastic extruders, comprising shaped members of wear-resistant material inserted in recesses in the work surface of the workpiece, the spaces between the walls of the recesses and the shaped pieces being filled with a binder. In order to minimize the expenses of manufacture and repair of the wear-protected workpiece and make it possible to use non-metallic wear-resistant material for the insert member, the recesses and the shaped members have walls which widen at least in two opposed regions, the largest dimension of the widened wall of the shaped member being equal to or smaller than the dimension of the opening of the corresponding recess so that the insert member is freely inserted into the recess and forms a space therewith in which a binder can be filled to form a locking means for the insert member in the workpiece.

Workpiece having wear-resistant inserts locked in recesses in the

A process for providing abrasion and corrosion resistance in the borehole of a steel body comprising placing an alloying material of solid form within the borehole of the steel body, the alloying material having abrasion and corrosion resistance, and thereafter melting the alloying material in a gas heated protective gas oven to effect diffusion bonding of the alloying material with the steel body and the formation of an abrasion and corrosion resistant lining on the steel body. The borehole is of non-circular shape in cross-section and, particularly, of figure 8 shape as shown in FIG. 2.

Process for the manufacture of a steel body with a borehole protected

In order to improve the wear-resistance of highly stressed surfaces of a kneading disc in a helical extruding machine, the exposed tips of the kneading disc are provided with inserts of an extremely wear-resistant, hard material. In a variety of embodiments, the tips of the lenticular kneading disc are provided with bores and recesses for receiving the hard inserts. Advantageously, the recesses are cylindrical wells in which cylindrical inserts are soldered or cemented. The inserts may be made from hard metals or ceramics, for example tool steel or tungsten carbide or the like.

Kneading disc for a screw extruder

A wear-resistant lining is provided in the work chamber of a screw extruder by providing an internal cavity in the extruder housing of a shape corresponding to the external cross-section of a wearing insert but sufficiently larger such that a gap of predetermined width is provided between the walls. A layer of soft, hardenable material is applied to the outer surface of the wearing insert to a thickness slightly greater than the gap. The extruder housing is heated until the cavity expands to a degree sufficient to allow insertion of the insert. The insert is then placed into the cavity and the material is allowed to harden, as by heat hardening due to the temperature of the extruder housing.

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Ditzingen, Germany

Gerhard Gnadig