An Investigation of the Suitability of Using a Sieglaff-McKelvey High Shear Rate Melt Rheometer for the Measurement of Low Viscosity Polymer Solutions.
Abstract
An investigation was made into the adaptation of a Sieglaff-McKelvey high shear rate melt rheometer for use in measuring low viscosity fluids. Using calibrated Newtonian oils, viscosities as low as 1.5 poise were found to be measurable with better than 5% accuracy over a shear rate range from a nominal 1000 1/S to 100,000 1/S at temperatures as low as 5 C above ambient. However, difficultieis were experienced in the measurement of low viscosity polymer solutions. With the stock capillaries 25.40 mm in length, a combination of wall slip and entrance/exit effects made calculating true viscosities impossible. It was concluded that capillaries with a diameter fo 1.0 mm or greater and variable lengths of up to 50 mm would be required to eliminate slip and still obtain a pressure drop within the measurable range of the instrument. To facilitate accurate measurement of low pressure drops, a new piston design was proposed using low-friction, low leakage Teflon o-rings. This would also expand the lower limits of the instrument's viscosity and shear rate ranges. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1984
- Accession Number
- ADA146275
Entities
People
- J. B. Hacker
Organizations
- Defence Research and Development Canada