Device for serial treatment of hollow bodies comprising a treatment rod slidingly controlled by an electric actuator and treatment method

A treatment device (30) for serial treatment of hollow bodies made of thermoplastic material, in particular preforms (12) made of thermoplastic material, comprising:

• a plurality of individual transport elements (32), each transport element being arranged for transporting a hollow body;
• a plurality of treatment rods (38), each treatment rod being associated with one of said transport elements (32), with each treatment rod (38) being mounted to slide axially in relation to the associated transport element (32) into the hollow body transported by passing through a neck (16) of said hollow body;
• a means for individually determining, for each hollow body, an expected extended position in which the treatment rod needs to be inserted axially into said hollow body, said expected extended position being shorter than an inner length of the hollow body;
• controlled means for moving each treatment rod (38) between a retracted position in which the treatment rod (38) is retracted above the hollow body transported by the transport element (32), and said extended position in which the treatment rod (38) is expected for that hollow body;
• wherein the controlled means comprise a plurality of individual electric actuators (42), each treatment rod being moved individually by one individual electric actuator with the controlled interruption of the operation of each individual electric actuator (42) being controlled individually by an electronic control unit (44) for stopping the associated treatment rod (38) in said extended position determined for said hollow body.