Flow induced filler orientation

The elongational flow field is determined from equation  

From the above equations it can be seen that orientation increases with aspect ratio and elongational strain rate. 

Talc filled thermoplastic materials were studied in rheometers of different geometries (elongational, capillary, parallel plate). Geometry of the testing method and the flow paths had an important influence on the orientation of talc particles. In addition to flow decrease, an increased concentration of filler had a pronounced effect on both flow and orientation. The cross-sectional distribution of particles de- 

Measurement of torque also provides data on the effect of fillers on the curing 

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Keywords filler, aspect ratio, particle shape, calcium carbonate, talc, platelets, reinforcement, glass fiber, kaolin, particle size, particle size distribution, chemical composition, adhesion, interface, aggregation, specific surface area, flow-induced orientation, hardness, surface free energy, surface tension, surface treatment, mechanical properties, thermal properties. 

A magnetic filler in the form of fiber was added to HDPE and injection molded test products were made. Anisotropic composites were manufactured to induce flow orientation of the fibers. The increased orientation contributed to the generation of a higher permeabihty magnet. The orientation can be affected by changing the die diameter. 

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