POST-MOLDING COOLING APPARATUS FOR PREFORMS MADE OF THERMOPLASTIC MATERIAL
The invention relates to an apparatus for cooling a plurality of preforms made of thermoplastic material which continuously move on a conveyor belt. The apparatus includes a cylindrical casing with a vertical extension formed by two coaxial cylinders, such a casing contains a guide crossed by a chain or a cable for transporting the preforms therein. The guide, which forms a closed path, comprises a first helical stretch, which raises from the lower plane starting from a station in which the preforms coming from a conveying device are hooked by the chain or by the cable, a second straight stretch, which returns the preforms to the lower plane once they have reached the upper plane, and a third flat stretch at the height of the lower plane, which returns the preforms to the arrival station. The helical stretch of the guide is contained within a cooling tunnel formed in the gap between the two walls of the outer cylinder and the inner cylinder of said casing. The cooling air is conveyed within the cooling tunnel by a specific manifold which is located within the casing.