Method for forming and filling a container by monitoring the pressure of liquid injected in the container

A method for simultaneously forming and filling a container by injecting a pressurized liquid in a preform, the container having a container volume, the pressurized liquid being injected from a pressurized liquid source to the preform along an liquid injection circuit while the preform is in a molding cavity defining the shape of the container, the method comprising:

• a first injection step injecting a first predetermined volume of the pressurized liquid into the preform at an injection speed, the first predetermined volume corresponding to a fraction of the container volume, the first injection step causing an expansion of the preform into a first intermediate container,
• a second injection step starting once the first predetermined volume of liquid has been injected, the second injection step including reducing the liquid injection speed relative to the liquid injection speed of the first injection step and injecting the pressurized liquid into the first intermediate container until a predetermined switch pressure in the liquid injection circuit is reached, the second injection step causing an expansion of the first intermediate container into a second intermediate container, and
• a third injection step starting once the predetermined switch pressure is reached, the third injection step including decelerating the liquid injection speed from the second injection step until liquid injection is stopped and the second intermediate container has expanded into the shape of the container.