Fabrication of Particle-Reinforced Polymers with Continuous Gradient Architectures Using Twin Screw Extrusion Process

The operation of the twin screw extrusion (TSE) process under transient conditions is investigated for the manufacture of particle-reinforced polymers with continuous gradient architectures. Mixing models of the residence time distribution (RTD) and residence volume distribution (RVD) are used to characterize the TSE process. By convolving the mixing models with the transient input conditions, a new convolution process model has been developed to predict the gradient architectures that evolve within the extrudate. In situ optical contrast measurements and a posteriori measurements of optical contrast, density, and solids loading are used to verify the convolution process model for a step change in the input conditions.