Use of optimized piston member for generating peak liquid pressure

A method for producing a container filled with a liquid from a preform having an inner volume, the method using an injection device comprising an inlet in fluidic communication with a source of the liquid, an outlet, and a chamber extending between the inlet and the outlet, the injection device further comprises a hollow control rod with a sealing ring extending in the chamber and arranged to close the outlet, the method comprising the steps of:

• placing the outlet in tight fluidic communication with the preform;
• injection the liquid from the source in the inner volume of the preform through the outlet;
• closing a sealing barrier between the inner volume and the liquid source, the closed sealing barrier forming a fluid tight closed volume, said closed volume including at least the inner volume, and wherein said closing of the sealing barrier takes place once the closed volume is full of liquid, said closing the sealing barrier being made by moving the hollow control rod
• from an injecting position wherein the outlet is in fluidic communication with the inlet chamber,
• to a sealing position wherein the sealing ring closes the chamber such that the sealing barrier isolates the closed volume from the rest of the chamber,
• placing a piston member in said closed volume, the piston member extending inside the hollow control rod, a sealing element between the piston member and the sealing ring forming a liquid tight engagement between the piston member and the sealing ring;
• and
• driving said piston member when the sealing barrier is closed such that the liquid pressure in the closed volume increases,
• wherein during the actuation of the piston member, the piston member enters at least in part inside the inner volume of the preform.

A method for producing a container filled with a liquid from a preform having an inner volume, the method using an injection device comprising an outlet and connected to the source of the liquid, the method comprising the steps of:

• placing the outlet in tight fluidic communication with the preform;
• injection the liquid from the source in the inner volume of the preform through the outlet;
• closing a rigid sealing barrier in the vicinity of the outlet between the inner volume and the liquid source, said sealing barrier comprising a port allowing a movement in a fluid tight manner of a piston member through the port, said rigid sealing barrier and said piston member forming a fluid tight closed volume, said closed volume including at least the inner volume, said closing of the sealing barrier taking place once the closed volume is full of liquid;
• and
• increasing the pressure of the liquid in the closed volume by moving the piston member though the port in the closed volume when the sealing barrier is closed,
• wherein during the actuation of the piston member, the piston member enters at least in part inside the inner volume of the preform.