摘要 |
A method for producing a vessel by stretch blow-molding in a mold from a preform made of plastic material includes heating the preform and introducing the preform in the mold. The preform is stretched by a rod displaced at a predetermined stretching speed. At a pre-blowing cue, the electrovalve is opened for establishing a communication between the inside of the preform and a gas source at a predetermined pre-blowing pressure and a pre-blowing flow rate. Pressure inside the preform is measured and a pressure peak is detected. The moment at which this pressure peak occurs and the corresponding pressure inside the preform is stored and compared with a predetermined moment and pressure for a theoretical pressure peak. Depending on the result, at least one of the following are modified: pre-blowing pressure, pre-blowing flow rate, pre-blowing cue, stretching speed, and heating temperature. |