What are the main factors that affect the moulding of bottle blanks?

The application of bottle blast mould is more extensive, its has high quality, energy saving, high efficiency, long service life and other characteristics, let more and more manufacturers favored, then, affect the bottle blast mould forming what are the factors, the following we understand together.


1. Polymer in the extruder conveying, melting, mixing, pumping out molding for the formation stage of the embryo; in this stage, the factors that affect the wall thickness distribution are:
1). The molecular weight distribution of the material and the average molecular weight;
2). The temperature control system of the blow molding machine and screw speed, which temperature control system includes hopper temperature, the temperature of the barrel 1 zone, 2 zone, 3 zone, 4 zone, flange temperature and storage die head 1 zone The temperature control system includes the hopper temperature, the temperature of the barrel zones 1, 2, 3 and 4, the flange temperature and the temperature of the storage head zone 1, zone 2, 3 and 4.

2. The stage in which the blanks are extruded from the gap between the die lip and the core is called the downstream stage. At this point, the common phenomena are die expansion and die draping. These two phenomena are influenced by the diameter of the blow moulding machine and the wall thickness control system, which includes the axial wall thickness control system and the circumferential wall thickness control system, which is used to adjust the gap between the mould lip and the mould core.



3. Embryo pre-blowing stage in order to avoid contact, adhesion of the inner surface of the embryo, plus improve the uniformity of the product wall thickness, to pre-blowing expansion of the embryo. In the pre-blowing stage, air is sprayed from below the embryo into the embryo to protect the embryo and reduce its draping and stretching. At this stage, the factors that influence the wall thickness distribution are: pre-blowing pressure and pre-blowing time.

4. During the high pressure blowing stage, the embryo is blown at high pressure to make it fit into the mould cavity and to achieve plastic forming of the product. At this stage, the common phenomenon is that the embryo is deformed by high pressure blowing, and the embryo is deformed by contact with the mould cavity. The factors affecting this situation are: the shrinkage rate of the material; the pressure and time of blowing; the material and structure of the mould; the mould exhaust system and the cooling system of the mould, such as the distribution of cooling water channels, the temperature of the cooling water intake, etc.