Flow divider and/or combiner valves are hydraulic components which are used to divide and/or combine flow in a predetermined ratio independent of loading conditions. Over the past years the authors have successfully designed valves which can divide and/or combine flow with an error of less than 3 percent for all loading conditions. More recently, a valve which can be used to divide and combine flow for a wide range of flow requirements and still maintain an error of less than 3 percent has been developed and has been labeled an “auto-regulated high precision flow divider/combiner valve”. The heart of the auto-regulated valve is the autoregulator itself. In this paper, the operation of the regulator is discussed and design criterion for acceptable performance presented. A linearized model is developed from which a number of valve parameters are established. A more complex model using the Power Bond Graph technique is presented, and transient responses to different flow inputs are compared to experimental data. The model and experimental responses were in good agreement; hence, it was concluded that the model could be used with confidence in future stability studies.

To optimize the preparation process for ethylene vinyl acetate (EVA)/rectorite nanocomposites during the melt extrusion, the effect of rectorite on the rheological property of molten polymer has been explored in this paper. The dispersion of rectorite in EVA was probed by X‐ray diffraction, and the rheological behaviors of EVA copolymer and EVA/rectorite nanocomposites during the extrusion process were investigated by means of HAAKE minilab. The positron results reveal that introducing the rectorite in EVA matrix increases the interfaces in composites. And the rheological results indicate that the viscosity of EVA and EVA/rectorite nanocomposites in the molten state was influenced by the processing temperature, processing time and shearing rate. For all the samples, the viscosity increases with increasing the shear rate, and decreases with increasing extrusion temperature. Moreover, compared with the pure EVA, the EVA/rectorite nanocomposite presents a lower viscosity at the same processing condition. Copyright © 2016 John Wiley & Sons, Ltd.

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