Process for cutting off defined lengths from strands of propellant charge powders

摘要

The present invention relates to a process for cutting off defined lengths from strands of propellant charge powders, emerging from an extruder. The defined lengths of the strands to be cut off are measured by means of a photoelectric cell which crosses the direction of movement of the powder strand to be cut off. This photoelectric cell is connected via an electronic system to a knife which cuts the strand off directly at the exit from the extruder. This knife has two mutually opposite cutting edges. It is moved by a pulse emitted by the electronic system. This pulse causes the knife always to move in only one direction; after this movement, it returns to the rest position. Under the next pulse, it moves in the direction opposite to that of the movement during the preceding pulse. Preferably, the direction of movement of the knife is an up-and-down movement.