Application of the Folgar-Tucker model to predict the orientation of particles of different aspect ratios in polymer suspensions

The increasing requirements on plastic parts demand a rising use of combined functional and reinforcing materials. Therefore, often reinforcing particles with different aspect ratios are added to the plastic as additive mixtures. However, the engineering design process of reinforced parts requires an early knowledge of the expected orientation of the reinforcing particles. Numerous models try to predict the orientation of particles in polymer suspensions. However, the interaction coefficient strongly depends on the aspect ratio of the particles and a prediction of the orientation behavior of additive mixtures with differently shaped particles has not been validated using conventional methods. In this work, the orientation of differently shaped particle mixtures in polymer suspensions is investigated for different fluid channel geometries. Finally, the Folgar-Tucker model is applied to filler mixtures and implemented into OpenFOAM (R), which enables the comparison of filler orientation in different fluid channel geometries. Regarding the experiments a characteristic increase of the interaction coefficient was observed at a filling level of 5%. Furthermore, it was shown that a balanced mixing ratio yields higher interaction coefficients. With regard to the performed simulations, it was possible to show qualitatively how a considered interaction between fibers and platelets affects the orientations.

Automated summary

This study investigates the orientation of differently shaped particle mixtures in polymer suspensions for different fluid channel geometries. The interaction coefficient showed a significant increase at a filling level of 5%, and it was demonstrated that a balanced mixing ratio yields higher interaction coefficients. The qualitative effects of the interaction between fibers and platelets on orientations were successfully demonstrated through simulations.