PROCESS FOR FORMING CONTAINERS, WHICH COMPRISES A STEP OF FLUSHING THE INTERNAL VOLUME OF THE CONTAINER OF VARIABLE DURATION OVER AT LEAST ONE GIVEN COMPENSATION TIME

摘要

Process for forming containers from a blank, preferably a preform, made of a thermoplastic, the containers being formed using a stretch-blow moulding machine of rotary type comprising at least one blow-moulding mould mounted on the periphery of a carousel rotated continuously about its axis, the blow-moulding mould operating in cyclic manner according to a blow-moulding cycle comprising the following steps: a step of placing a preheated blank in a blow-moulding mould; a step of closing the blow-moulding mould; a step of blowing the blank in the blow-moulding mould; a step of flushing the inside of the container with a cooling gas, by injecting air thereinto; a step of grasping the blow-moulded container by external gripping means; and a step of opening the blow-moulding mould, which process consists in automatically varying the duration of said flushing step at each start of production of the containers, in a temporary and evolving manner for a few minutes, in order to establish, in said containers, thermal conditions enabling the first containers to be formed at a temperature that gives them a final volume corresponding to the final volume of the containers formed during the stead-state operation of said stretch-blow moulding machine.