ABSTRACT
With respect to the history of sciences and techniques, it is a common observation that pragmatical engineering, or even craft industry, came before—often, by several centuries—the scientific understanding of material properties and/or natural phenomena exploited in industrial operations. Over the twentieth century, the rubber industry has developed special rheometers, essentially factory floor instruments either for checking process regularity or for quality control purposes, for instance, the well-known Mooney rheometer, the oscillating disk rheometer, and the rotorless rheometer. At sufficiently low strain, most polymer materials exhibit a linear viscoelastic response and, once the appropriate strain amplitude has been determined through a preliminary strain sweep test, valid frequency sweep tests can be performed. Rubber compounds are complex polymer systems and a brief discussion on their hidden complexity is an interesting preliminary step in foreseeing the rheological test techniques that can be best considered.
