The blow molding machines are mainly divided into three categories: extrusion blow molding machines, injection blow molding machines and special structure blow molding machines . The processing technology is mainly divided into two kinds of one-step method and two-step method. One-step and two-step blow molding machine molding process, mainly used for PET and BOPP hollow container molding. Both have their own characteristics and are widely used. In comparison, the two-step method is more suitable for centralized production of preforms and dispersed blown bottles; and the one-step method is more suitable for online production of beverage companies.
The blowing process of the blow molding machine mainly has 6 steps:

1) First put the heated plastic embryo into the mold;

2) Use a clamping cylinder to tighten the mold;

3) Lock the mold with high pressure or mechanical structure;

4) Medium and high pressure pre-blowing, meanwhile, the action of stretching the cylinder makes the mold expand;

5) High pressure blowing, the preform is shaped according to the mold, and the pressure is maintained for a certain time;

6) Release the high pressure in the formed bottle and reset the cylinder-take the bottle.

Pneumatic equipment is used in many places during the operation of the blow molding machine; from unloading-locking-stretching-high-pressure blowing \ deflation-taking bottles, this series of actions are assisted by pneumatic equipment. Such as stretching the high-pressure air blowing and deflation circuit, the gas path is divided into two parts, the atmospheric part and the high pressure part