Automatic PET Bottle Blow Molding Machine Process

Automatic PET Bottle Blow molding machine is to do a good job of preforms through a certain process into the bottle of the machine. At present, most of the blow molding machines are used two-step blowing method, that is, preheating - blowing molding.

First, warm up

The preform will be heated by the high temperature lamp, the body part of the preform heating softening, in order to maintain the shape of the bottle, the embryo mouth is not required to heat, so the need for a cooling device to its cooling operation.

Second, blowing molding

The stage is to have been preheated preforms have been placed in the mold has been done, the high pressure inside the inflatable, the bottle into the required bottle of the bottle.

Blowing process is a two-way stretching process, in which the PET chain was bidirectional extension, orientation and arrangement, thereby increasing the mechanical properties of the bottle wall, improve the tensile, tensile, impact strength, and very Good air tightness. Although the stretch helps to improve the strength, but can not be too much to stretch, to control the good stretch blow ratio: radial not more than 3.5 to 4.2, axial not more than 2.8 to 3.1. The preform wall thickness should not exceed 4.5mm.

The blowing is carried out between the glass transition temperature and the crystallization temperature, and is generally controlled between 90 and 120 degrees. PET in this range of performance for the high elasticity, rapid blow molding, cooling and forming a transparent bottle. In a one-step process, this temperature is determined by the length of the cooling time in the injection molding process (such as Aoki Blow Molding Machine), so to connect the good note - blowing the relationship between the two stations.

Blowing process: stretching - a blow - the second blow, three action time is very short, but must be with the good, especially the first two steps determine the overall distribution of the material, the quality of the blown good or bad. It is advisable to adjust the temperature of the preform, such as the timing of the start of the drawing, the drawing speed, the pre-blowing start and finish, the pre-blow pressure, the pre-blow air flow, etc. The temperature gradient of the inner and outer walls of the blank. In the rapid blow molding, cooling process, the bottle wall has induced stress. For inflatable beverage bottles, it is resistant to internal pressure and is good, but for hot filling bottles it is necessary to ensure that it is released at full above the glass transition temperature.

Borun Machinery are able to supply different types of PET bottle blowing machine according to customer's bottle size and shapes, we have both semi automatic type and fully automatic type.  Welcome to contact with us for more details.