New Findings from Case Western Reserve University in the Area of Rheology Described (High strain extensional rheometry of polymer melts: Revisiting and improving the Meissner design)
By a News Reporter-Staff News Editor at Journal of Technology -- Data detailed on Rheology have been presented. According to news reporting from Cleveland, Ohio, by VerticalNews journalists, research stated, "A new extensional rheometer limited in achievable strain only by sample rupture is presented. The rheometer is based on the Meissner design of two pairs of counter-rotating rollers pulling a sample of fixed length but is small enough to fit inside the oven of a standard rotational rheometer and thus is dubbed the Meissner Extensional Rheometry Accessory (MERA)."
The news correspondents obtained a quote from the research from Case Western Reserve University, "The true strain rate is calculated by visually accessing the sample during deformation using a high-speed digital camera. Extensional experiments were performed on three materials representing a wide range expected rheological behavior, a styrene-butadiene rubber blend, a linear polystyrene, and a branched low-density polyethylene. The MERA was able to accurately replicate the results of the well-known Sentmanat extensional rheometer (SER) design in terms of onset of strain-hardening and absolute transient extensional viscosity values. However, due to its design, it was possible to achieve homogeneous extensional flow up to real Hencky strains in excess of 8, which corresponds to a linear stretch in excess of 3000. By comparison, the SER is limited to one drum revolution, which corresponds to a Hencky strain of 3.5-4.0 or a maximum linear stretch of approximately 50."
According to the news reporters, the research concluded: "Previously the highest Hencky deformations reported in the literature are for the filament stretching extensional rheometer and Rheometric Scientific RME apparatus and in both cases approach 7, which corresponds to a linear stretch of approximately 1000."
For more information on this research see: High strain extensional rheometry of polymer melts: Revisiting and improving the Meissner design. Journal of Rheology, 2014;58(4):869-890. Journal of Rheology can be contacted at: Journal Rheology Amer Inst Physics, Ste 1 No 1, 2 Huntington Quadrangle, Melville, NY 11747-4502, USA.
Our news journalists report that additional information may be obtained by contacting R.J. Andrade, Case Western Reserve University, Dept. of Macromol Sci & Engn, Cleveland, OH 44106, United States. Additional authors for this research include P. Harris and J.M. Maia.
Keywords for this news article include: Ohio, Rheology, Cleveland, United States, North and Central America
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