yield point in thickening

Thickeners + Rheology Guide - Scott Bader

a certain yield stress is reached. Beyond this point the fl ow is then that of a pseudoplastic fl uid. Pseudoplastic behaviour is portrayed below in two different plot types: Shear Stress Shear Rate Newtonian Fluid: Viscosity Shear Rate Pseudoplastic Fluid: Shear Stress Shear Rate Pseudoplastic Fluid: Area A Force F Upper moveable plate Lower fi xed plate x y γ Speed v. 4 Thickeners ...

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Determining and Understanding the Yield Stress of

11/11/2015  In some methods, the initial drop in G' is considered as a measure of the yield point because at this point non-linearity sets in and the structural breakdown occurs. In some other methods, the cross-over of G'/ G" is taken as the yield point, as this indicates the transition from solid to liquid characteristics. The yield zone is the span between these two events because it represents solid to

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RHEOLOGY AND RHEOLOGICAL MEASUREMENTS

thickening. Some liquids at rest appear to behave like solids until the shear stress exceeds a certain value, called the yield stress, after which they flow readily. Some commonly observed types of flow behavior are shown in Figure 2, in which the shear stress is plotted against shear rate. These plots are called flow

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Basics of rheology :: Anton Paar Wiki

The yield point is the lowest shear-stress value above which a material will behave like a fluid, and below which the material will act like a – sometimes very soft – solid matter (according to prEN ISO 3219-1). The yield point or yield stress is the minimum force that must be exceeded in order to break down a sample’s structure at rest, and thus make it flow.

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Dilatant Fluid - an overview ScienceDirect Topics

The yield point (YP) of Bingham plastic fluids can be calculated using the following formula: (2.7) τ y = θ N 1 − μ p N 1 300 If the rotary speed of the Fann VG meter is chosen to be N 1 = 300 rpm, this equation degenerates to τ y = θ 300 − μ p .

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Determining and Understanding the Yield Stress of

In some methods, the initial drop in G' is considered as a measure of the yield point because at this point non-linearity sets in and the structural breakdown occurs. In some other methods, the cross-over of G'/ G" is taken as the yield point, as this indicates the transition from solid to liquid characteristics. The yield zone is the span between these two events because it represents solid to liquid transition.

More

Basics of rheology :: Anton Paar Wiki

The yield point is the lowest shear-stress value above which a material will behave like a fluid, and below which the material will act like a – sometimes very soft – solid matter (according to prEN ISO 3219-1). The yield point or yield stress is the minimum force that must be exceeded in order to break down a sample’s structure at rest, and thus make it flow.

More

Thickeners + Rheology Guide - Scott Bader

in the range 8.0-9.5 to ensure optimum thickening effi ciency and maintenance of a stable viscosity. If a volatile alkali such as ammonia is used, care should be taken to avoid loss of the alkali and lowering of the pH as viscosity reduction may occur. In some cases it may be

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Dilatant Fluid - an overview ScienceDirect Topics

The yield point (YP) of Bingham plastic fluids can be calculated using the following formula: (2.7) τ y = θ N 1 − μ p N 1 300 If the rotary speed of the Fann VG meter is chosen to be N 1 = 300 rpm, this equation degenerates to τ y = θ 300 − μ p .

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Polyacrylate-33 for Thickening and Suspending in Low ...

20/09/2013  The yield stress point of a formula can be defined as the minimum stress value applied to initiate flow. When the stress is below the yield point, the system displays elastic or solidlike behavior. Beads dispersed in a formulation will thus remain suspended if the yield point in the medium is sufficient to overcome the effects of settling or buoyancy of those particles.

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Thickener Design and Theory Problems - 911 Metallurgist

09/06/2019  Thickening Regimes . Coe and Clevenger believed that throughout “free settling” the settling velocity u was a function of C only. In mathematical terms, u = u(C). About compression they made the following statement: “The water liberated by compression finds its way out of zone D” (their compression zone) “through tubes or channels which form drainage systems upwards through the

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The Effect of Base Oils on Thickening and Physical ...

solvency and thickener yield; a relationship with real economic value for grease manufacturers. Figure 1. Thickener content required for NLGI Grade 2 greases with different base oils, wt% Physical properties including mechanical stability, roll stability, dropping point, oil separation, and mobility

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Thickeners - 911 Metallurgist

01/06/2016  The practice of thickening or clarification is usually carried out in decantation tanks employing gravity settling or sedimentation. These tanks are fitted with mechanical scrapers to collect and move the settled solids to the point of discharge, the clear overflow being collected and removed by means of peripheral launders.

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Viscosity Rheology Glossary from the Centre for ...

Yield Stress. A structured fluid, such as an emulsion or suspension, possesses a yield stress. This is the stress that must be applied to disrupt internal structure (due to colloidal or other interactions) and elicit a significant decrease in viscosity. The presence of a yield stress can imbue products with desirable handling, appearance and storage properties. Yield stress can be measured using both oscillatory

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Rheology - SlideShare

21/02/2016  The thixotrophy phenomena can be observed by constructing consistency curves. From the graph up curve ab is obtained, up to maximum point b. If the rate of shear is reduced, then down curve bc is obtained. In Non-Newtonian system, the down curve is displaced to left of the up curve. In this graph, the material has low consistency at any rate of shear on down curve compared to that shown

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Thickeners + Rheology Guide - Scott Bader

in the range 8.0-9.5 to ensure optimum thickening effi ciency and maintenance of a stable viscosity. If a volatile alkali such as ammonia is used, care should be taken to avoid loss of the alkali and lowering of the pH as viscosity reduction may occur. In some cases it may be

More

Polyacrylate-33 for Thickening and Suspending in Low ...

20/09/2013  The yield stress point of a formula can be defined as the minimum stress value applied to initiate flow. When the stress is below the yield point, the system displays elastic or solidlike behavior. Beads dispersed in a formulation will thus remain suspended if the yield point in the medium is sufficient to overcome the effects of settling or buoyancy of those particles.

More

Thickener Design and Theory Problems - 911 Metallurgist

09/06/2019  Thickening Regimes . Coe and Clevenger believed that throughout “free settling” the settling velocity u was a function of C only. In mathematical terms, u = u(C). About compression they made the following statement: “The water liberated by compression finds its way out of zone D” (their compression zone) “through tubes or channels which form drainage systems upwards through the

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Generality of shear thickening in dense suspensions

yield stress. This suggests the yield stress resulting from attractions is responsible for hiding shear thickening if it overwhelms the shear-thickeningstressrange. For a more-detailed exploration than afforded by chemical means of the role of the magnitude of the yield stress in modifying the shear-thickening regime, we require in situ, tunable control

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The Effect of Base Oils on Thickening and Physical ...

solvency and thickener yield; a relationship with real economic value for grease manufacturers. Figure 1. Thickener content required for NLGI Grade 2 greases with different base oils, wt% Physical properties including mechanical stability, roll stability, dropping point, oil separation, and mobility

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Fluid friction - PetroWiki

04/06/2015  where τ y is called the yield point, K is consistency index, and m is the exponent, referred to as power-law index. Dilatant. These fluids also exhibit a linear relationship between shear stress and shear rate when plotted on a log-log paper and are illustrated as Curve D in Fig. 1. The shear stress expression for dilatant fluid is similar to power-law fluid, but the exponent n is greater ...

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Thickeners - 911 Metallurgist

01/06/2016  The practice of thickening or clarification is usually carried out in decantation tanks employing gravity settling or sedimentation. These tanks are fitted with mechanical scrapers to collect and move the settled solids to the point of discharge, the clear overflow being collected and removed by means of peripheral launders.

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Tailingsfo Thickened Tailings Storage - A discussion

They are not to be confused with paste tailings which are a higher (and more expensive) degree of thickening to produce very dense slurry that is often pumped to its final storage facility using positive displacement pumps (however, centrifugal pumps can be used to pump paste where the tailings properties are favourable). HDTT is often defined in industry where the tailings have a high yield ...

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Viscosity Rheology Glossary from the Centre for ...

Yield Stress. A structured fluid, such as an emulsion or suspension, possesses a yield stress. This is the stress that must be applied to disrupt internal structure (due to colloidal or other interactions) and elicit a significant decrease in viscosity. The presence of a yield stress can imbue products with desirable handling, appearance and storage properties. Yield stress can be measured using both oscillatory

More

Rheology - SlideShare

21/02/2016  The thixotrophy phenomena can be observed by constructing consistency curves. From the graph up curve ab is obtained, up to maximum point b. If the rate of shear is reduced, then down curve bc is obtained. In Non-Newtonian system, the down curve is displaced to left of the up curve. In this graph, the material has low consistency at any rate of shear on down curve compared to that shown

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Understanding the Thickening Process

The thickening process is the primary method of producing high solids slurries for the minerals industry. Thickener outputs can accommodate a range of tailings disposal options from low yield stress, easily pumped suspensions for disposal in conventional ‘wet’ tailings dams to more concentrated slurries for delivery to ‘dry disposal’ and backfill applications. The thickening process ...

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Thickener Design and Theory Problems - 911 Metallurgist

09/06/2019  Thickening Regimes . Coe and Clevenger believed that throughout “free settling” the settling velocity u was a function of C only. In mathematical terms, u = u(C). About compression they made the following statement: “The water liberated by compression finds its way out of zone D” (their compression zone) “through tubes or channels which form drainage systems upwards through the

More

Thickeners - 911 Metallurgist

01/06/2016  The practice of thickening or clarification is usually carried out in decantation tanks employing gravity settling or sedimentation. These tanks are fitted with mechanical scrapers to collect and move the settled solids to the point of discharge, the clear overflow being collected and removed by means of peripheral launders.

More

Fluid friction - PetroWiki

04/06/2015  where τ y is called the yield point, K is consistency index, and m is the exponent, referred to as power-law index. Dilatant. These fluids also exhibit a linear relationship between shear stress and shear rate when plotted on a log-log paper and are illustrated as Curve D in Fig. 1. The shear stress expression for dilatant fluid is similar to power-law fluid, but the exponent n is greater ...

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Lube Tech 115 The effect of base oils on thickening and ...

may be made with a specific amount of thickening agent, i.e., grease yield, varies by thickener type and by the solvency of the oils used to prepare the grease. As the grease yield increases, the thickener content decreases, which consequently lowers the cost of the formulation since the thickener system is generally the highest priced component.

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Tailingsfo Thickened Tailings Storage - A discussion

They are not to be confused with paste tailings which are a higher (and more expensive) degree of thickening to produce very dense slurry that is often pumped to its final storage facility using positive displacement pumps (however, centrifugal pumps can be used to pump paste where the tailings properties are favourable). HDTT is often defined in industry where the tailings have a high yield ...

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How Do I Thicken my Cosmetic Formula

Thickening systems for typical shampoos will need to de- velop Newtonian flow, which is the type of flow you see with water or honey; the fluid retains its original viscosity but is allowed to flow freely. There is no yield value, or minimum force that needs to be exerted before flow will take place.

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Using Rheology to Characterize Flow and Viscoelastic ...

Shear thinning, shear thickening, Yield stress oViscosity vs. temperature. TAINSTRUMENTS.COM Flow Behaviors. TAINSTRUMENTS.COM Information from a Flow Curve 1 1) Sedimentation 2) Leveling, Sagging 3) Draining under gravity 2 3 6 5 8 9 1.00E-5 1.00E-4 1.00E-3 0.0100 0.100 1.00 shear rate (1/s) 10.00 100.00 1000.00 1.00E4 1.00E5 log η 1.00E6 7 11 4 10 What shear rate? 8) Spraying and

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Selecting Rheology Modifiers for Adhesives

Selecting Rheology Modifiers for Adhesives Rheology modifiers improve the viscosity and have a great impact on the application characteristics of adhesive and sealant formulations. They help you to adjust the flow properties as well as prevent settling down of fillers during settling and transportation in your formulation. Explore the importance and role of rheology modifiers along with their ...

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