At present, most mineral water bottle blowing machines on the market are two-step linear automatic blowing machines. First, let us briefly introduce the working principle and industrial process of this kind of bottle blowing machine:
A. Working principle of mineral water bottle blowing machine
1. Warm up
The preform is irradiated by the infrared high temperature lamp, the preform is heated and softened. In order to keep the bottle mouth from deforming, the bottle mouth needs to be cooled and protected.
2. Blow molding
The preheated preform is placed in the ready-made bottle blowing mold, and the inside is filled with high pressure. Blow and pull the preform into the desired bottle.
The automatic bottle blowing machine combines the two operations of bottle blowing through the operation of the manipulator, which realizes automatic production and greatly accelerates the production rate.
B. The process flow of the bottle blowing machine
The blow molding process of the bottle blowing machine is a two-way stretch process. In this process, the PET chain is extended, oriented and placed in two directions, thereby increasing the mechanical properties of the bottle wall and improving the tensile, tensile and impact strength. , And has excellent air tightness. Although stretching helps to increase the strength, it should not be excessively stretched. The stretch-inflation ratio should be controlled well: do not exceed 4.2 in the radial direction and 3.1 in the axial direction.
Bottle blowing is performed between the glass transition temperature and the crystallization temperature, usually between 90 and 120 degrees. In this interval, the PET exhibits a highly elastic state, which becomes a transparent bottle after rapid blow molding and cooling.
Blow molding process includes: stretching-blowing once-blowing twice. The three actions have a very short time, and they must be well coordinated to blow out a perfect and beautiful bottle. In particular, the first two steps determine the overall dispersion of the bottle material and the quality of the bottle blowing, so it is necessary to adjust: stretching speed, pre-blowing time, pre-blowing pressure, pre-blowing flow, etc.