6. Wire or cable drive

This function is performed by caterpillar tracks or capstans (figure 24 ) located downstream of the cooling tank. The distance must be sufficient to ensure that the polymer temperature is below the deformation temperature when the wire (and cables) pass over the driving element. The tensile force is measured by the torque exerted on the drive motors of the caterpillar or capstan.

Sometimes an additional drive system is required before the extruder head to unwind the wire and regulate the wire tension in the line. Tension is measured by a strain gauge located on a pulley shaft after the input capstan. This measurement is compared with the setpoint. The speed of the drive systems is regulated to maintain this setpoint.