FILLERS IN DIFFERENT PROCESSING METHODS

This chapter contains a discussion of the important changes in the methods of production and in the process parameters which are required to effectively incorporate fillers. The other goal of this discussion is to evaluate the effect of filler incorporation on the properties of final products manufactured by various methods of polymer processing. 

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. 

Similar data come from processing of polyamide-6 with glass fibers. Diameter swell, thickness swell, and weight swell were all substantially decreased by the 

The addition of fillers to blow molded materials does not require special equipment but frequently the process parameters must be adjusted to compensate for the changes in the rheological properties of the melt. Larger additions of fillers tend especially to introduce non-Newtonian characteristics which require careful consideration. Also, timing of processes requires adjustment to deal with the higher nucleation rate caused by the presence of filler. 

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