Evaluation of high shear viscosity data from jet and concentric cylinder viscometers

1962 ◽  
Vol 2 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Roger S. Porter ◽  
Julian F. Johnson
Keyword(s):  
Shear Viscosity ◽  
Viscosity Data ◽  
High Shear ◽  
Concentric Cylinder

scholarly journals Assessment Mixing and Compaction Temperatures for Modified HMA Using Superpave High Shear Viscosity Methods

2018 ◽  
Vol 21 (4) ◽  
pp. 516-522 ◽  
Author(s):  
Alaa Hussein Abed ◽  
Ali Hwaidi Nasser
Keyword(s):  
Shear Viscosity ◽  
Asphalt Mixture ◽  
High Shear ◽  
Compaction Temperature ◽  
Modified Asphalt ◽  
Performance Grade ◽  
Modified Binders ◽  
Different Temperatures ◽  
Marshall Stability

The objective of this study is determining the mixing and compaction temperature of the modified asphalt mixture. Results of binder tests showed that the addition of 3% SBS  to control asphalt (PG 64-16) would achieve the desired performance level (PG 76-16) a performance grade that fits our climate with traffic loads. When using 5% SBS the performance grade of binder increased three grades (PG 82-16) and when increasing SBS content to 8% the performance grade increased four grades (PG 88-16). At shear rate of 500 (s-1), the modified asphalt viscosity can be obtained at different temperatures and the viscosity temperature curve can be achieved. As a result, the mixing and compaction temperature of modified asphalt can be determined to reach 0.17 ± 0.02 Pa.s and 0.28 ± 0.03 Pa.s for mixing and compaction, respectively. It is noted that SBS modified reached a viscosity of 3 Pa.s when 8 % additive. Additive contents above these values may not be suitable for good workability and pump ability according to Superpave specifications. While addition of 5% SBS with control asphalt, more than 3.7times at 135°C Increase the viscosity. Marshall Stability test indicated that the strength for the SBS specimens increases as compared to the conventional specimens. An increase of about 39%, 74%, 102%, was observed with 3%SBS 5%SBS 8%SBS modified binders, respectively. The Marshall test results for 8%SBS binders required compaction temperatures above 175°C need to keep up quality of HMA item while limiting natural effect amid development, these proposals are unsatisfactory Modified mixtures the 5% SBS modification was determined to be the maximum useful content. The Superpave method to estimate mixing and compaction temperatures show are not practical for use with modified binders. Also,  it is observed that good agreement values between the average Marshall compaction temperature and the High Shear Viscosity Method (HSRV) and   lower than Superpave methods Where the decline ranges from 15 ºC to 17 ºC.

scholarly journals RHEOLOGICAL ANALYSIS OF VEGETABLE OILS USED FOR BIODIESEL PRODUCTION IN BRAZIL

2015 ◽  
Vol 14 (2) ◽  
pp. 31 ◽  
Author(s):  
L. E. Silva ◽  
C. A. C. Santos ◽  
J. E. S. Ribeiro ◽  
C. C. Souza ◽  
A. M. S. Sant’Ana
Keyword(s):  
Shear Stress ◽  
Rheological Properties ◽  
Vegetable Oils ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Biodiesel Production ◽  
Viscosity Data ◽  
Concentric Cylinder ◽  
Lower Shear ◽  
Different Temperatures

Rheology attempts to define a relationship between the stress acting on a given material and the resulting deformation and/or flow that takes place. Thus, the knowledge of rheological properties of fluid materials such as vegetable oils generates auxiliary data that can be used in its storage and application. In this context, the aim of this study was to evaluate the rheological behavior of vegetable oils (cotton, canola, sunflower, corn and soybean) at different temperatures, using four rheological models (Ostwald- de-Waelle, Herschel-Bulkley, Newton and Bingham). The rheological properties were determined using a Thermo Haake rheometer with concentric cylinder geometry. Measurements were taken at 30, 45 and 60 °C by controlling the temperature using a thermostatic bath coupled to the equipment. The software Rheowin Pro Job Manager was used for process control and data record. The rheograms were obtained by measuring the values of shear stress varying the shear rate from 100 to 600 s-1 within 250 seconds. For the analysis of the apparent viscosity at different shear rates was applied simple linear regression until 2nd degree with the aid of SAS (SAS/Stat 9.2) program. The apparent viscosity data were submitted to analysis of variance and the averages were compared by Tukey test at 5% of probability. Higher temperatures of the samples were correlated to lower shear stress values, hence lower values for viscosity and consistency index were obtained, since it is known that the density and viscosity are highly sensitive to temperature and that the increase in temperature results in reduction of viscosity, benefiting the fluid flow. The models of Newton and Ostwald-de-Waelle were chosen to evaluate the rheological behavior of the samples, showing a good fit for the rheological data.

On the 3D Printability of Multi-Walled Carbon Nanotube/High Density Polyethylene Composites

2019 ◽  
Author(s):  
Felicia Stan ◽  
Nicoleta-Violeta Stanciu ◽  
Catalin Fetecau
Keyword(s):  
Carbon Nanotube ◽  
Electrical Properties ◽  
3D Printing ◽  
Shear Viscosity ◽  
High Density Polyethylene ◽  
High Density ◽  
High Shear ◽  
Shear Rates ◽  
Mechanical And Electrical Properties ◽  
Multi Walled Carbon Nanotube

Abstract This study focuses on 3D printing of multi-walled carbon nanotube/high density polyethylene (MWCNT/HDPE) composites. First, rheological properties of 0.1, 1, and 5 wt.% MWCNT/HDPE composites were investigated to estimate the 3D printability window. Second, filaments with 1.75 mm diameter were fabricated and subsequently extruded by a commercial 3D printer. Finally, the filaments and 3D printed parts were tested to correlate the rheological, mechanical, and electrical properties with processing parameters. Experimental results show that flow behavior of MWCNT/HDPE composites is a critical factor affecting the 3D printability. The shear viscosity exhibits good shear thinning behavior at high shear rates and significantly increases with increasing nanotube loading from 0.1 to 5 wt.%, at low shear rates. Reliable MWCNT/HDPE filaments were obtained with smooth surface finish and good mechanical and electrical properties. The 0.1 and 1 wt.% MWCNT/HDPE filaments exhibit very good printing characteristics. However, under the flow conditions of a standard 0.4-mm nozzle, 3D printing of 5 wt.% MWCNT/HDPE filament can be rather difficult primarily due to high shear viscosity and nozzle clogging. Thus, further investigation is needed to fully optimize the 3D printing of MWCNT/HDPE composites.

STOPCOCK LUBRICANTS

1949 ◽  
Vol 27f (9) ◽  
pp. 318-322 ◽  
Author(s):  
J. R. Farnand ◽  
I. E. Puddington
Keyword(s):  
Shear Viscosity ◽  
Linear Relation ◽  
High Shear ◽  
Flow Properties

The addition of appropriate quantities of finely divided solids to hydrocarbon, silicone, and glycerol base lubricants has been found to increase their life in stopcocks manyfold. The flow properties of the dispersions show that those solids that materially increase the high shear viscosity, without contributing greatly to the thixotropy of the system, are the most effective. This effect is produced by solids that have a polarity similar to that of liquid vehicle and are readily wetted by the vehicle. Under these conditions, a linear relation exists between the viscosity of the lubricants at a mean rate of shear of 1000 sec.–1 and their life in the stopcock.

scholarly journals Universality of steady shear flow of Rouse melts

2020 ◽  
Vol 59 (10) ◽  
pp. 755-763 ◽  
Author(s):  
Leslie Poh ◽  
Esmaeil Narimissa ◽  
Manfred H. Wagner
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Stress Relaxation ◽  
Shear Flow ◽  
Normal Stress ◽  
Shear Viscosity ◽  
Viscosity Data ◽  
Stress Growth ◽  
Model Predictions

Abstract The data set of steady and transient shear data reported by Santangelo and Roland Journal of Rheology 45: 583–594, (2001) in the nonlinear range of shear rates of an unentangled polystyrene melt PS13K with a molar mass of 13.7 kDa is analysed by using the single integral constitutive equation approach developed by Narimissa and Wagner Journal of Rheology 64:129–140, (2020) for elongational and shear flow of Rouse melts. We compare model predictions with the steady-state, stress growth, and stress relaxation data after start-up shear flows. In characterising the linear-viscoelastic relaxation behaviour, we consider that in the vicinity of the glass transition temperature, Rouse modes and glassy modes are inseparable, and we model the terminal regime of PS13K by effective Rouse modes. Excellent agreement is achieved between model predictions and shear viscosity data, and good agreement with first normal stress coefficient data. In particular, the shear viscosity data of PS13K as well as of two polystyrene melts with M = 10.5 kDa and M = 9.8 kDa investigated by Stratton Macromolecules 5 (3): 304–310, (1972) agree quantitatively with the universal mastercurve predicted by Narimissa and Wagner for unentangled melts, and approach a scaling of Wi−1/2at sufficiently high Weissenberg numbers Wi. Some deviations between model predictions and data are seen for stress growth and stress relaxation of shear stress and first normal stress difference, which may be attributed to limitations of the experimental data, and may also indicate limitations of the model due to the complex interactions of Rouse modes and glassy modes in the vicinity of the glass transition temperature. Graphical abstract

The Measurement of Viscosity of Liquids Under Tension

2003 ◽  
Vol 125 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Peter A. Kottke ◽  
Scott S. Bair ◽  
Ward O. Winer
Keyword(s):  
Shear Viscosity ◽  
Initial Pressure ◽  
Viscosity Coefficient ◽  
Absolute Zero ◽  
Viscosity Data ◽  
Hydrostatic Tension ◽  
Low Shear Viscosity ◽  
Low Shear

The rheological significance of a state of hydrostatic tension was investigated. A method for measuring the limiting low shear viscosity of liquids under tension was developed. The ability of nine liquids to withstand tension was verified, and the magnitudes of tension achievable through different methods were compared. The use of viscosity data from liquids under tension to more accurately determine the initial pressure viscosity coefficient was investigated. The continuity of the pressure viscosity coefficient across absolute zero pressure was verified.

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