The process flow of the bottle blowing machine

The blow molding process of the bottle blowing machine is a two-way stretching process. In this process, the PET chain extends in two directions, oriented and arranged to increase the mechanical properties of the bottle wall and its tensile, tensile and impact strength. The tightness is very good. Stretching will help increase strength, but it should not be overstretched. It is necessary to control the stretch-expansion ratio.

Blow molding is carried out between the glass transition temperature and the crystallization temperature, usually controlled between 90 and 120 degrees. In this gap, PET exhibits a very elastic state and becomes a transparent bottle after rapid blow molding, cooling and solidification. In the one-step method, the temperature is determined by the length of the cooling time during the injection molding process, so the relationship between the injection station and the blow molding station must be connected.
The blow molding process is as follows: one blow molding stretches once, and two blow moldings. These three actions are short, but need to be well coordinated. Specifically, the first two steps determine the overall distribution of materials and the quality of blowing bottles. Therefore, you need to adjust the stretching start time, stretching speed, pre-blowing start and end time, pre-blowing pressure, pre-blowing flow, etc. The bottle controls the overall temperature distribution of the preform and the temperature gradient between the inner and outer walls of the preform.
During the rapid blow molding and cooling process, induced stresses are generated on the bottle wall. For gas-filled beverage bottles, it is beneficial to withstand internal pressure, but for hot-filled bottles, you need to ensure that they are completely released above the glass transition temperature.