Design and manufacture of self-wiping extruder for the reaction extrusion of melamine formaldehyde

Extruders are by far the most important machines in polymer processing. Of these processes the reaction extrusion has recently attracted new interests. Reaction extrusion of thermosets has presented new difficulties in process uniformity and production continuity. To achieve a required degree of stability a special design of self-wiping scrrews for a co-rotating twin screw extruder has to be made. In this work such a screw has been designed and manufactured, and its performance has been checked for a reaction extrusion of melamine formaldehyde. The results of the stability of the process and the quality of the products are reported.