Blow-molding operation

The major difference between injection and extrusion blow molding is the way the soft hollow tube (called a preform or parison) is made. In injection blow molding, two different molds are used. One mold forms the preform and the other mold is used in the actual blow-molding operation to give the final shaped article. In the molding process, the softened material preform, from the preform mold, is introduced into the blowing mold and blow-molded to... 

Fig. 1-1. Complete extrusion and injection blow molding operation the FALLO approach.

Rosato DV, Rosato AV, Di Mattia DP, editors. Blow molding handbook technology, performance, markets, economics the complete blow molding operation. 2nd ed. Munich Carl Hanse Verlag 2003. 

Blow molding is a fabrication process used for forming hollow plastic articles. There are five basic types of blow molding operations ... 

There are three principal types of blow-molding operations extrusion blow molding (Fig. 9-4), injection blow molding (Fig. 9-5), and stretch blow molding. 

Fig. 9-8 Three-station injection blow-molding operation [1].

Table 9-3 shows the advantages and disadvantages of the three principal types of blow-molding operations. 

TABLE 9-3 Advantages and Disadvantages of Blow-Molding Operations... 

Orientation processes also take place in blow-molding operations. A particularly significant aspect is biaxial stretch blow molding, in which the polymer preform is stretched both in the hoop and axial directions. 

False Neck n In blow molding of containers, a neck construction that is additional to the neck finish of the container and that is only intended to facilitate the blow-molding operation. Afterwards the false neck is removed from the container. 

Consider again an idealized blow molding operation where a eylindrical container of dimensions shown in Figure 10.15. Also assume that the metal mold can be idealized as a cylindrical container with a wall thickness of 50 mm as shown in Figure 10.15. 

For this idealized blow molding operation the objectives are the following ... 

In blow molding operations, a tubular parison of moltem polymer, usually produced by an extruder, is blown by gas pressure (p) against the walls of a metal mold, as illustrated in Figure 10.11. 

In an idealized blow molding operation consider that both the parison and final shape are cylindrical as shown in Figure 10.12. Assume... 

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