Sequential extrusion blow molding

Figure 6.1 2 Examples of different shaped sequential extrusion blow molding products...

Sequential extrusion blow molding is a special multi-material technique (Fig. 10.41) used for the production of technical articles. The different materials are chosen typically to contribute complementary mechanical properties and are present in distinct sequential zones in the finished part. Normally two materials... 

Two basic methods are used in this process to deliver material to the processing units. These are extrusion and injection. In the next step, the preformed material is expanded to form parison. There are many commercial variations on this basic technique some of which include continuous-extrusion-blow-molding, coextrusion-and-sequential-blow-molding, and injection-stretch-blow-molding. Both extrusion and injection molding are the subjects of later discussions below, we will concentrate here on the parison formation, its processing, and the related effects. 

Air ducts are produced by sequential extrusion or blow molding alternating rigid PBT sections and soft elastomeric polyester accordion sections, which reduces weight, cost, number of components, and NVH. 

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