Abstract: A device for measuring the rate of recovery of a foam sample under compression includes a compression surface engageable with the foam sample and a displacement transducer disposed in mechanical communication with the compression surface. A process of measuring the rate of recovery of the foam sample under compression includes exerting a compressive force on the foam sample such that the foam sample is compressed by a predetermined percentage of its thickness, releasing the compressive force, and measuring the thickness versus time of the recovering foam sample as it returns to its pre-deformed state.

Abstract: Liquids of different viscosity are mixed together more rapidly and with less energy consumption by elongating drops of the more-viscous liquid prior to mixing them into the less-viscous surrounding liquid. The more-viscous drops are elongated past a critical aspect ratio that is a function of the ratio of the viscosities of the two liquids and of the relative volume fractions they occupy. The rate at which the more-viscous drops mix into the surrounding liquid is dependent on the amount of shear strain required to stretch the drops to their critical aspect ratio, and thus, if the drops begin the mixing process already elongated, the rate of mixing is greater. In polymer blending operations, wherein a tumbled mixture of polymer pellets are melted and blended, the more-viscous pellets are elongated in the pelletizing operation. The mixing technique can be applied whenever the more-viscous drops are distributed discontinuously through a mixture, i.e., whenever they do not form a continously connected matrix.