Method of keeping the geometry of an extrudate constant

摘要

In the case of an extruder for extruding profiles with a control loop for the mass throughput, it has been found that changes in mass throughput are detected too slowly and that, as a result, countermeasures in response to changes in mass throughput cannot be initiated in time. In order to overcome these disadvantages, it is proposed to provide the mass throughput control with a secondary control for constant melt pressure upstream of the extruder die. As a result, profiles of an optimum weight per metre and optimum geometry can be achieved.