U-043

Mechatronic Design of a Squeezing Flow Rheometer

Authors: Fred R. Stolfi & Kevin Craig
Affiliation: Xerox Corporation (Fred R. Stolfi) & Rensselaer Polytechnic Institute (Kevin Craig)

Abstract
This paper describes the analysis, simulation and design of an instrument to characterize polymeric materials at high speed. The work comprises a study in the field of mechatronics. Mechatronics is the synergistic combination of precision mechanical engineering, electronics, control systems and computers. Each of these components is required for the instrument; it was only through their synergy that the goal of high-speed operation is achieved. Indicative of a mechatronics approach, the mechanical design includes a direct drive actuator, a simple means of obtaining precision motion. Inertia is minimized. Wideband, low noise, electronics are used in the feedback control loop and for the sensors that measured various mechanical variables. A feedback control system gives the instrument, the reference signal tracking, disturbance rejection and robustness to unmodeled dynamics required for its operation. This control system, therefore, provides the system functionality for the mechanical components. Finally, a computer system is used for data acquisition, parameter determination and reference signal generation. The whole instrument is clearly more than the sum of its component parts.

The primary scientific advance from this work is that this instrument enables a characterization of polymers with a precision and speed not previously available. The instrument measures the viscoelastic rheological properties of polymers at high rates of strain. Further, the instrument characterizes the cohesive properties of polymers under high-speed transient extension.

Kevin Craig
craigk@rpi.edu

Fred R. Stolfi
FStolfi@crt.xerox.com