Method for controlling parison wall thickness and a wall thickness control signal generator circuit for carrying out the method

摘要

The present invention discloses an arrangement wherein a wall thickness of a plastic bottle formed by means of a blow-molding process is formed into the desired configuration by controlling the wall thickness of a parison from which the bottle is made. A control pin arranged opposite an extrusion outlet of an extruding machine for adjusting the wall thickness of the parison is finely moved in response to a fine step-like control voltage signal to thereby suitably set and vary the opening degree of the extrusion outlet of the extruding machine, thus obtaining the desired wall thickness for the parison.