2007 rheology brochure revc:rheology brochure ar rheology brochure.pdf2007 rheology brochure...

Rheometers

TA INSTRUMENTS

-R2007C-ENG

2007 Rheology Brochure RevC:Rheology Brochure 10/3/07 3:11 PM

WWW.TAINSTRUMENTS.COM

TA INSTRUMENTS, WORLDWIDE

More worldwide customers choose TA Instruments than any

competitor as their preferred rheometer supplier. We earn this

distinction by best meeting customer needs and expectations for high

technology products, quality manufacturing, timely deliveries, excellent

training, and superior after-sales support.

2007 Rheology Brochure RevC:Rheology Brochure 10/3/07 3:11 PM Page 6

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ARES

G2

ARAR

ARES

G2

AR Rheometer Innovations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

AR-G2 Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

AR 2000ex Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

AR 1500ex Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

AR Rheometer Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

AR-G2 Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

AR 2000ex Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

AR 1500ex Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

New AR-G2 Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Smart Swap™ Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

AR RHEOMETERS

ARES-G2

AR

ARES-G2 Rheometer Innovations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

ARES-G2 Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

ARES-G2 Technical Specifications / Torque and Normal Force Transducer . . . . 12

ARES-G2 Technical Specifications / Advanced Brushless DC Drive Motor . . . . . 14

ARES-G2 Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

ARES-G2 Environmental Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

ARES-G2 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

• New Castle, DE USA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +1-302-427-4000

• Linden, Utah USA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +1-801-763-1500

• Järfalla, Sweden . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +46-8-564-72-200

• Crawley, United Kingdom . . . . . . . . . . . . . . . . . . . . . . . . . . . . +44-1293-658900

• Shanghai, China . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +86-21-54263960

• Taipei, Taiwan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +88-62-25638880

• Tokyo, Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +81-3-5479-8418

• Soeul, Korea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +82-2-3415-1500

• Bangalore, India . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +91-80-28398963

• Paris, France . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +33-1-30-48-94-60

• Eschborn, Germany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +49-6196-400-600

• Brussels, Belgium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +32-2-706-0080

• Etten-Leur, Netherlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +31-76-508-7270

• Milano, Italy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +39-02-27421-283

• Barcelona, Spain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +34-93-600-9300

• Melbourne, Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +61-3-9553-0813

• Mexico City, Mexico . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5255-5524-7636

Local Offices


QUALITY PRODUCTS

All rheometers are manufactured according to ISO 2000 procedures in

our New Castle, DE (USA) or our Crawley, (UK) facilities. Innovative

flow manufacturing procedures and a motivated, highly-skilled work force

ensure high quality products with industry-leading delivery times.


SALES & SERVICE

We pride ourselves in the technical competence and

professionalism of our sales force, whose only business is

rheology and thermal analysis. TA Instruments is recognized worldwide for its

prompt, courteous and knowledgeable service staff. Their specialized knowledge

and experience are major reasons why current customers increasingly endorse

our company and products to their worldwide colleagues.


AR RHEOMETERSThe AR Series rheometers offer unmatched performance and ease-of-use due to unique and superior design.

These technologies are optimized and integrated into rheometer systems that deliver the best fundamental rheology

measurements. Continuous innovations drive each generation of the AR Series for better performance and improved

testing efficiency. Unprecedented low-torque performance, unparalleled stress and direct strain control, intuitive software,

and a versatile design make the AR Series the obvious choice for the widest range of applications.

ARSENSITIVE • VERSATILE • RELIABLE

TA InnovationsFirst commercial controlled stress rheometer

First commercial rheometer with a magnetic bearing

UHP/EHP Active Temperature Control

Optical encoder technology

Drag cup motor technology

First high-torque drag cup motor

Patented drag cup temperature sensor

Smart Swap™ technology

Smart Swap™ gometries

Real-time waveform display and storage

ETC camera viewer

Streaming video with sample image capture software

First rheometer with Peltier technology

Isolated normal-force transducer

Navigator software


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AR

Minimum Torque Oscillation CR 0.003 µN.m

Minimum Torque Oscillation CS 0.003 µN.m

Minimum Torque Steady CR 0.01 µN.m

Minimum Torque Steady CS 0.01 µN.m

Maximum Torque 200 mN.m

Torque Resolution 0.1 nN.m[1]

Motor Inertia 18 µN.m.s[2]

Angular Velocity Range CS 0 to 300 rad/s

Angular Velocity Range CR 1.4E-9 to 300 rad/s

Frequency Range 7.5E-7 to 628 rad/s

Displacement Resolution 25 nrad

Step Change in Velocity 7 ms

Step Change in Strain 30 ms

Direct Strain Control Standard[2]

Thrust Bearing Magnetic

Normal/Axial Force Range 0.005 to 50 N

Smart Swap™ Standard

Smart Swap Geometry Standard

Peltier Plate -40 to 200 °C[3]

Environmental Test Chamber (ETC) -160 to 600 °C

ETC Camera Viewer Optional

Concentric Cylinder -20 to 150 °C[3]

Peltier Control

Upper Heated Plate -30 to 150 °C[3]

Electrically Heated Plate (EHP) -70 to 400 °C

Camera Option with StreamingVideo and Image Capture Optional

AR-G2TA Instruments is proud to announce another breakthrough in rheometertechnology. The new AR-G2 is the first commercial rheometer withpatented(1) magnetic thrust bearing technology for ultra-low, nano-torquecontrol. The AR-G2 is packed with new features including new patented(2)

advanced drag cup motor technology, Smart Swap™ (3) Geometries,streaming video and image capture software, ETC camera viewer andethernet communications. With improvements in nearly every rheometerspecification, the performance of the AR-G2 stands alone. It is the mostadvanced controlled stress, direct strain and controlled rate rheometeravailable.

CR - Controlled Rate ModeCS - Controlled Stress Mode

[1] Internal Resolution for D to A converter at torque of 0.1 µN.m[2] Direct Strain Control provides single cycle oscillation and continuous oscillations during experiments.

[3] Lower temperature limits require use of a suitable fluid in an external circulator.

(1) Patent # 7,017,393 (2) Patent # 6,798,099 (3) Patent # 6,952,950


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AR

Minimum Torque 0.1 µN.m

Minimum Torque 150 mN.m

Torque Resolution 1 nN.m[1]



Angular Velocity Range CR 1.00E-7 to 300 rad/s



Step Change in Velocity 7ms

Step Change in Strain 30ms

Thrust Air Bearing Porous Carbon

Smart SwapTM Standard


Peltier Plate Camera Optional

Peltier Concentric Cylinder -20 to 200 °C[2]


Electricall Heated Plates -70 to 400 °C

AR 1500exThe new AR 1500ex is a highly sensitive and rugged general-purpose rheometer for fluids and soft solids. It includes many of the same design features incorporated in our AR-G2 and AR 2000ex, such as high-resolutionoptical encoder, durable porous carbon bearings with low residual torque,and a low-inertia drag cup motor. The AR 1500ex has broad specificationranges and a wide variety of popular Smart Swap™ temperature systems including Peltier Plates, Peltier Concentric Cylinder, Electrically Heated Plates,and both a Dry Asphalt System and Asphalt Submersion Cell. The AR 1500exoffers unprecedented value in a robust cost-effective package for bothresearch and quality control.

AR 2000exThe AR 2000ex brings an all new electronics package to the time-tested hardware of the world’s best selling rheometer, further extending the longlist of unique features. The AR 2000ex rheometer design includes a unique,ultra-low inertia drag cup motor and porous carbon air bearings for outstanding controlled stress, direct strain and controlled rate performance. The AR 2000ex features the original Smart Swap™ quickinterchanging and self-configuring environmental systems. Enhanced features of the AR 2000ex include the new ETC with fast heating rates, ETC and Peltier Camera Viewers (with image capture software), a new Electrically Heated Plate Temperature System, and ethernet communications. The AR 2000ex is extremely versatile and appropriate for a wide variety of applications including fluids of any viscosity, polymer melts, solids and reactive materials.

Minimum Torque Oscillation CR 0.03 µN.m

Minimum Torque Oscillation CS 0.1 µN.m

Minimum Torque Steady CR 0.05 µN.m

Minimum Torque Steady CS 0.1 µN.m

Maximum Torque 200 mN.m

Torque Resolution 1 nN.m[1]



Angular Velocity Range CR 1E-8 to 300 rad/s



Step Change in Velocity 25 ms

Step Change in Strain 60 ms

Direct Strain Control Standard[3]

Thrust Bearing Porous Carbon Air

Normal/Axial Force Range 0.005 to 50 N

Smart Swap™ Standard


Environmental Test Chamber (ETC) -160 to 600 °C

Concentric Cylinder -20 to 150 °C[4]

Peltier Control


Electrically Heated Plate (EHP) -70 to 400 °C

[1] Internal Resolution for D to A converter at torque of 1 µN.m[2] Lower temperature limits require use of a suitable fluid in an external circulator.


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AR

TMA

3

1

5

6

THE AR SERIES

REPRESENTS A FAMILY OF

RHEOMETERS UNIQUELY

DESIGNED TO DELIVER

OPTIMUM SYSTEM

PERFORMANCE.

1 DRAG CUP MOTOR

The motor applies torque, and controls speed and oscillation frequency. Drag cup motors, unlike some motor designs, can apply extremely smooth acceleration and are ideal for creep and recovery measurements. Inertia is kept to an absolute minimum, reducing the influence of the system on test resultsin oscillation and transient measurements. The result is more accurate measurements of weak material structures and faster response to step changes intorque and strain.

4 OPTICAL ENCODER

Low inertia optical encoders are used in all AR rheometers for high-resolution measurement of angular displacement (strain) and speed (shear rate)over wide ranges. The ability to measure very small displacements allows for the characterization of very delicate material structures. The ability to measure and control a wide range of speed adds to the instrument’s versatility.

3 RADIAL AIR BEARINGS

Radial air bearings provide stiffness and support in the radial direction. All AR Rheometers are uniquely designed with two porous carbon radialbearings. The dual radial bearing design is ideal for the testing of high-stiffness samples, such as solids in torsion as well as soft solids and low-viscosity fluids.

2 THRUST BEARING

Thrust bearings provide stiff, “frictionless” axial support of the drive shaft and measuring geometry. The low-end torque performance of the instrument depends on residual bearing friction, which results in residual torques. The AR-G2 incorporates the new magnetic thrust bearing whilethe AR 2000ex and AR 1500ex use porous carbon bearings.

6 RIGID ONE-PIECE ALUMINUM CASTING & LINEAR BALL SLIDE

All TA rheometers are designed to minimize system deflection in order to maximize the deformation applied to the sample. AR rheometers are builton a rigid, single-piece aluminum casting and the rheometer head assembly is attached to the casting via a rigid linear ball slide. A motor and anoptical encoder are located in the base of the frame to drive the ball slide vertically and measure its movement. This ensures precision positioningof the geometry with an accuracy of 1 micron. TA Instruments’ rheometers are built to last and deliver a lifetime of reliable performance.

5 NORMAL FORCE TRANSDUCER

A unique AR rheometer feature is the design and placement of the normal force sensor. The highly-sensitive, ultra-stiff, normal force sensor is isolated from the motor and bearing assembly, and located below the lower geometry. The benefit of isolating the normal force transducer is twofold. First, both the normal force sensor and the motor/bearing assembly are designed for maximum stiffness. When shearing a viscoelasticmaterial, the normal force generated by the sample pushes against the measuring surfaces. Minimizing movement is key to accurate normal forcemeasurements. Second, the normal force sensor is environmentally isolated for thermal stability.

AR TECHNOLOGY

AR 4

2


AR

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Breakthrough technologies make our new AR-G2 the world’s most advanced controlled stress, direct strain and

controlled rate rheometer. With a revolutionary, patented, magnetic levitation thrust bearing and new patented drag

cup motor technology, unprecedented nano-torque control is now possible adding a new dimension to rheological

characterization. New patented Smart Swap™ Geometries and Real-Time Streaming Video and Image Capture

features take ease-of-use to a new level. The AR-G2 represents a whole new approach to rheometer technology.

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1 MAGNETIC

THRUST BEARING

Why a magnetic bearing? Larger gaps in the absence of a continuous flow of pressurized air, translates tounprecedented low levels of friction in the bearing. Moreimportantly, the ability to control and measure torquesin the nanoN.m range. No other rheometer can boastsuch low-end torque sensitivity. The larger gap in the thrust bearing is robust and not susceptible to contamination. The additional benefits of the magneticbearing over traditional air bearing designs are the following:

• Ultra low torques applied to the sample• Smaller sample volumes can be used• Ability to probe delicate material structures• Study of low viscosity materials over a broad

range of conditions

AR TECHNOLOGY - AR-G2

1

2

3

3

2 PATENTED DRAG CUP MOTOR

Our new patented advanced drag cup motor is designed to further reduce system friction by increasing the motor gap by 100%. Dramatic improvements in low end torque performance are realized without compromising high-end performance. The motor delivers enhanced transient response and an extended angular velocity control range. The motor incorporates a patented drag cup temperature sensor. For the firsttime in any rheometer design, the temperature of the drag cup is measured, ensuring the most accurate torque output.

3 RADIAL AIR BEARING

The AR-G2 incorporates two porous carbon radial air bearings located near the top and bottom of the drive shaft. Contributions to friction from theradial bearings is minimal. The combination of magnetic thrust and radial air bearings makes the AR-G2 a commercially viable and robust solutionfor new levels of low torque performance, without sacrificing the high-torque performance.


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AR

1 AR 2000exDRAG CUP MOTOR

The AR 2000ex drag cup motor providessix decades of torque with extremely lowmoment of inertia. The AR 2000ex motorwas designed specifically to provide superior controlled stress, controlled rate,step-strain, and direct oscillation strain control. The AR 2000ex provides stablehigh torque output by avoiding heat issuesthrough the careful selection of motor drivefrequency, coupled with internal cooling ofthe drag cup.

2 POROUS CARBON AIR BEARINGS

The AR 2000ex has a unique triple air bearing design. A single thrust bearing [2A] and two radial porous carbon air bearings [2B] provide maximum axial and radial stiffness. This configuration ensures confidence in measurements of high modulus materials, while providing low and uniform levels of residual torque.

3 OPTICAL ENCODER

The AR 2000ex measures angular deflection and speed, using a low inertia, high-resolution optical encoder. The ability of the AR 2000ex to measure small angular displacements, and low and high angular velocities adds to its versatility.

AR TECHNOLOGY - AR 2000ex

The AR 2000ex is the world’s most popular rheometer. With a broad torque range, superior strain resolution,

wide frequency range, and ingenious convenience features, it is extremely versatile and appropriate for a wide

variety of applications including low viscosity fluids, polymer melts, solids and reactive materials. 2B

3

2A

1

2B


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AR

AR TECHNOLOGY - AR 1500EXThe AR 1500ex is a robust, cost-effective, general-purpose rheometer. It features a unique motor design, durable thrust

and radial jet air bearings, and high-resolution optical encoder. With a generous torque range, it is ideal for

characterizing the rheological behavior of complex fluids and soft solids. The AR 1500ex can be configured with Peltier

plate or concentric cylinder temperature systems. Normal force control and measurement capability is optional at the time

of purchase or can be added as a future upgrade.

3 OPTICAL ENCODER

The AR 1500ex measures angular deflection and speed, using a low inertia, high-resolution optical encoder. The ability of the AR 1500ex to measure small angular displacements, and low and high angular velocities adds to its versatility.

2 POROUS CARBON

AIR BEARINGS

The AR 1500ex has a unique triple air bearingdesign. A single thrust bearing [2A] and two radial porous carbon air bearings [2B] provide maximum axial and radial stiffness. Thisconfiguration ensures confidence in measurements ofhigh modulus materials, while providing low anduniform levels of residual torque.

1 AR 1500ex

DRAG CUP MOTOR

The AR 1500ex drag cup motor provides sixdecades of torque with extremely low moment of inertia. The AR 1500ex motor was designedspecifically to provide superior controlled stress, controlled rate and step-strain control. The AR 1500ex provides stable high torque outputby avoiding heat issues through the careful selection of motor drive frequency, coupled with internal cooling of the drag cup.

2B

3

2A

1

2B


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AR

MAGNETIC

THRUST BEARING

The AR-G2 is the first commercial rheometer built witha patented magnetic thrust bearing. More traditionalrheometer designs incorporate air bearings for low friction support of the drive shaft. Although air bearingsare sometimes referred to as “frictionless,” there is stillfriction present, mostly due to the high pressure air andsmall clearances. The AR-G2 magnetic thrust bearingprovides a gap measured in millimeters as opposed tomicrons, as in traditional air bearing designs. This translates to unprecedented low levels of friction in thebearing and more importantly, the ability to control and measure torques in the nN.m range. No otherrheometer can boast such low-end torque sensitivity inboth controlled stress and controlled strain modes. The larger gap in the thrust bearing is robust and notsusceptible to contamination.

NEW AR-G2 TECHNOLOGY

ACTIVE TEMPERATURE CONTROL (ATC)

The AR-G2 Electrically Heated Plate (EHP), Upper Heated Plate (UHP), and Dry Asphalt System all incorporate our new patented(1) non-contact temperature sensor for active measurement and control of the upper plate temperature, using a special draw rod. The draw rod houses a microPCB and Platinum Resistance Thermometer. The PRT senses temperature atthe upper cone or plate geometry, and the signal is transmitted from a secondary coil on the draw rod to a primary coil in the head assembly.Together with a PRT in the lower plate, real-time control of both plates is possible. The AR-G2 is the first rheometer to actively measure and control theupper plate temperature. (1) Patent # 6,931,915

SMART SWAP™ GEOMETRIESThe AR-G2 features our new patented Smart Swap Geometries with automatic detection. Smart Swap geometries include an integrated magnetic cylinder that stores unique geometry information. When attached, the information is automatically read and the software is configured with appropriate parameters (type, dimension, material). The Smart Swap option brings the AR-G2 one step closerto being a truly “Intelligent” rheometer system.

12

3 4

5

1 HOUSING

2 MICRO PCB3 PRIMARY COIL

4 SECONDARY COIL

5 PRT


SMART SWAP™ ACCESSORIES

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AR

CONCENTRIC CYLINDER

Concentric Cylinders are commonly used for very low viscosity fluids, dispersions of limited stability, and applications where fluid/solvent evaporation may be a problem. The Smart Swap Concentric Cylinder system featuresPeltier temperature control and provides a temperature rangeof -20 to 150 °C with heating rates up to 15 °C/min.

PELTIER PLATE

The most common temperature control option for the AR rheometers is the Peltier plate. AR Series Peltierplates have a temperature range of -40 to 200 °C with a typical heating rate of up to 20 °C /min and a temperature accuracy of +/- 0.1 °C. A PRT (platinum resistance thermometer) sensor positioned at the center of the plate ensures accurate temperature measurement and control. The peltier plate is also availablein a “stepped” model that uses removable lower plates. This unique design allows the peltier plate to easilybe configured with custom lower plates and cups. Other peltier accessories include: peltier imersion cover, solvent trap, purge cover, and camera viewer.

SMART SWAP™ TEMPERATURE SYSTEMS

Only TA Instruments offers the convenience and versatility of Smart Swap temperature control options.Smart Swap temperature control options are attached to the instrument on its unique magnetic base.Intelligent Smart Swap options can be interchanged in as fast as 10 seconds. Once attached, the instrument automatically detects and configures the system.

UPPER HEATED PLATE (UHP)

The UHP is designed for use with the Smart Swap™ Peltier Plateand provides both upper plate temperature control and anenclosed purge gas environment. Designed for optimum heattransfer and minimum thermal equilibration time, the UHP setsa new standard in non-contact heating. Automated zero heatflow calibration yields temperature gradients of less than +/- 0.1 °C. The UHP is modeled to provide matched upper andlower plate temperature during heating ramps of up to 15 °C/min to a maximum temperature of 150 °C. The AR-G2UHP features our new patented Active Temperature Control, ATC.The ATC makes the AR-G2 UHP the only Peltier/upper heatedplate system combination available that incorporates direct temperature control of both the upper and lower plates. Flexiblecooling options include an external circulator or innovative vortexcooling.


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AR


UV CURING

Two Smart Swap accessories for rheological characterization of UV curable materials are available for the AR-G2 and AR2000exrheometers. One accessory uses a light guide and reflecting mirror assembly to transfer UV radiation from a high-pressure mercury light source. The UV Light Guide accessory is configured using a lower Smart Swap assembly with light source mount, collimator, and 5 mm light guide. A UV light source (Exfo Omnicure S2000), with wavelengths in the range of 320 to 500 nm, andtriggering cable are optional. A second accessory uses self-contained LED’s to deliver UV light with a very narrow band around apeak of 365 nm. Both the LED and Light Guide Accessories include removable 20 mm quartz plate, remote radiometer/dosimeter,UV light shield, and nitrogen purge cover for working under ambient conditions. Optional temperature control to a maximum of150 °C is available using AR Series Electrically Heated Plates (EHP) option. Disposable plates are available for hard UV coatings thatcannot be removed from the plates once cured.

DRY ASPHALT & ASPHALT SUBMERSION TEMPERATURE SYSTEMS

The AR Series offers a traditional Asphalt Submersion Cell and new Dry Asphalt temperature control accessories. Both temperature systems meet SHRP, ASTM, and AASHTO requirements, and include 8 mm and 25 mm parallel plates and samplemolds. The Dry Asphalt System combines our superior Upper Heated Plate with a unique lower stepped Peltier Plate. Automatedzero heat flow calibration yields temperature gradients of less that +/- 0.1 °C. The AR-G2 Dry Asphalt System features our newly-patented Active Temperature Control, ATC. The ATC makes the AR-G2 Dry Asphalt system the only stepped Peltier/upperheated plate system combination available that incorporates direct temperature control of both the upper and lower plates.Flexible cooling options includes an external circulator or innovative vortex cooling. The Asphalt Submersion Cell is a direct portof temperature control technology used on our popular CSA series of rheometers. Temperature control of an asphalt sample is byfluid submersion.

DRY ASPHALT WET ASPHALT UV LIGHT GUIDE UV LED



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AR

ELECTRICALLY HEATED PLATES (EHP)

The EHP is a Smart SwapTM temperature option that providesactive heating and cooling of parallel plate and cone and plate geometries. The EHP is perfect for rheological characterization ofpolymer melts up to a maximum temperature of 400 °C. Otherfeatures include an environmental cover and heated purge gas.An optional Gas Cooling Accessory for temperature control to -70˚C. An optional clear purge cover is available for sampleviewing and integration with camera viewer. Additionally, for theAR-G2, the EHP offers patented Smart Swap Geometries andnewly patented Active Temperature Control, ATC. ATC makes theAR-G2 EHP the only electrically heated plate system capable ofdirect temperature control of both the upper and lower plates.

ENVIRONMENTAL TEST CHAMBER (ETC)

The ETC uses a controlled convection/radiant-heating concept and is available for AR-G2 and AR 2000ex Rheometers. It istypically used for polymer applications and can be used with parallel plate, cone and plate, disposable plate, and rectangular torsion clamps for solids. The ETC has a temperature range of –160 to 600 °C with heating rates up to 60 °C/min . It can be connected directly to a bulk liquid nitrogen source for subambient temperature control. The ETC features our new camera viewer with remote illumination and focusing. Used in conjunction with the new streaming videoand image capture software, real-time images can be displayed in the software and an image is stored with each data pointfor subsequent viewing. The ETC camera viewer is an ideal tool for data validation.



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AR

INTERFACIAL ACCESSORY

Traditionally, rheometers have been used to characterize the bulk properties of materials. In many materials, such as pharmaceuticals, foods,personal care products and coatings, there is a two-dimensional liquid/liquid or gas/liquid phase with distinct rheological properties. In the past, massive biconical geometries have been used to make limited interfacial measurements in steady shear mode. The ultra-low friction nano-torque sensitivity of the AR-G2 has now been combined with a Pt/Ir Du Noüy Ring system, enabling viscoelastic characterization of interfaces in oscillation and transient modes. This makes the AR-G2 the only rheometer in the world capable of measuringbulk rheology, as well as both steady shear and dynamic interfacial properties of materials.

DYNAMIC INTERFACIAL SHEAR RHEOLOGY USING THE AR-G2The dynamic interfacial shear moduli G’ and G” are used to monitor the network structure build-up, resulting from the adsorption of proteins at the interface. Proteins unfold at the interface and, therefore, are crucial to the stability of emulsions and foams. The measurement is done with a Du Noüy Ring, consisting of a Pt-Ir wire, positioned at the interface of two liquids, or a liquid and air in a circular glass dish. The ultra-sensitive, nano-torque range of the AR-G2 rheometer is required to make these measurements. Figure 1 showsthe dynamic storage modulus of this material continuously increases as the protein migrates to the surface and forms a network structure.

0.03

0.025

0.02

0.015

0.01

0.005

0

0 50 100 150

time (minutes)

G‘,

G’’ (

N/m

)

STARCH PASTING CELL (SPC)

The SPC is a powerful and accurate tool for rheologicalcharacterization of the gelatinization process and finalproperties of starch products. It uses TA's innovativenew impeller design for superior mixing and control ofsedimentation during testing. A precision temperaturecontrolled chamber, with heating/cooling rates up to30 °C/min controls and measures actual sample temperature and is designed to minimize water lossduring the cooking cycle.

PRESSURE CELL

The Pressure Cell is an optional accessory for use withthe Peltier controlled Smart Swap Concentric CylinderSystem. The Pressure Cell is a sealed vessel that canbe pressurized to 140 bar (2000 PSI), over a temperature range of -10 °C to 150 °C. The cylinderin the vessel is driven using an innovative high-powered magnetic coupling and low-frictionbearing design. The cell is ideal for characterizingmaterials that volatilize under atmospheric pressure.

FIGURE 1

Figure 1: Absorption of a 0.05% whey protein solution in distilled water.


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ARES

G2

AR

APPLICATIONS

STRAIN SWEEP

Key viscoelastic parameters (G’, G”, η*, tanδ, etc.) can bemeasured in oscillation as a function of stress, strain, frequency, temperature and time. Figure 4 illustrates an oscillation strain sweep used to determine the onset of non-linear viscoelastic behavior. In the linear viscoelastic region(LVR), the material responds linearly to a stress or strain inputand the moduli G’ and G” are independent of strain. The internal structure of the material remains intact under lineartesting conditions. Beyond the limit of the LVR the material’sresponse is highly non-linear. The dynamic moduli G’ and G”drop rapidly with increasing strain and higher harmonic stresscontributions appear. Under these high strain test conditions thematerials experiences a catastrophic breakdown of the internalstructure. Rheological analysis using higher harmonics in thenon-linear oscillation regime is referred to as “FourierRheology”.

FLOW CURVEFOR DISPERSIONS

A generalized flow curve for dispersions is illustrated inFigure 1. TA rheometers generate flow curves by applying astress ramp (or shear rate) and measuring the shear rate (or stress). Flow curves can also be produced using “steadystate” flow where each viscosity data point is generated at a constant stress after equilibration. The data generated provides information on yield stress, viscosity, shear thinning, shear thickening, thixotropy, and correlates to processing and product performance. Simple techniques likespindle viscometers can only measure a point or a small partof the total flow curve.

FLOW CURVE FOR POLYMERS

Figure 2 shows a generalized flow curve for polymers andcorresponding process shear rate ranges. A polymer’s molecular weight greatly influences its zero shear viscosity,while its molecular weight distribution and degree of branching affect its shear rate dependence. These differences are most apparent at low shear rates not possible with melt flow index or capillary devices. TA rheometers can determine molecular weight based on themeasured zero shear viscosity. Cox-Merz and TTS can be used to extend the data to higher shear rates.

VISCOELASTIC PROPERTIES

The viscoelastic properties of polymer melts are commonlystudied in the dynamic oscillation mode. Figure 3 illustratesa viscoelastic fingerprint for a linear homopolymer andshows the variation of the storage modulus (GI) and lossmodulus (GII) with frequency. Since polymer melts are viscoelastic, the mechanical response will be time dependent,so low frequencies correspond to long times. TTS is used toextend the range of data to higher and lower frequenciesand to build a master curve at a reference temperature. The magnitude and shape of the GI and GII curves dependson the molecular structure of the polymer.

1 Sedimentation 2 Leveling, Sagging 3 Draining under gravity 4 Chewing and swallowing 5 Dip coating 6 Mixing and stirring 7 Pipe flow 8 Spraying and brushing 9 Rubbing 10 Milling pigments in fluid base 11 High Speed coating

log

η

shear rate (1/s)

10-5 10-3 10-1 101 103 105

56 8 9

4

1 2 3 117 10

Extended Range with Oscillation & Cox-Merz

Extended Range with Time-Temperature Superpositions (TTS) & Cox-MerzMeasure in Steady Shear

ηo = Zero Shear Viscosityηo = K x MWc3.4

log

ηo

shear rate (1/s)

10-310-5 10-1 101 103 105

Molecular Structure Compression Molding Extrusion Blow and Injection Molding

Typical range Frequency sweep

log

G’ a

nd G

” (Pa

)

1011

109

107

105

103

101

10-2 100 102 104

log Frequency (rad/s)

Terminal Region

Extended range w/TTS

G’G’’

Extended range w/TTS

Rubbery Plateau Region

Transition Region

Glassy Region

106 108 1010

G“G‘

Linear Region Non-Linear Region

104

103

102

101

0.0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

100

10-5

Strain

Mod

ulus

G',

G''

(Pa)

Magnitude R

atio l3 /l1 , l5 /l1 , l7 /l1

10-1 10010-2 10110-4 10-3

FIGURE 2FIGURE 1 FIGURE 3 FIGURE 4


-52- -53-

ARES

G2

AR

DYNAMIC MECHANICAL

PROPERTIES OF SOLIDS IN

TORSION

The ability to characterize the viscoelastic properties of solidsin torsion is a feature of TA Instruments’rheometers, as illustrated in Figure 5 for polycarbonate (PC). Transitionsor relaxations of molecular segments are observed as stepchanges in the storage modulus, and as peaks in the lossmodulus and damping. The magnitude and shape of the storage modulus (GI), loss modulus (GII) and damping (tan delta) will depend on chemical composition, crystallinity,molecular structure, degree of cross-linking, and the typeand amount of fillers.

TRANSIENT TESTS (CREEP AND

STRESS RELAXATION)

In a creep recovery test, illustrated in Figure 6, a constantstress is applied to the sample and the resulting strain ismeasured over time. The stress is then removed and therecovery (recoil) strain is measured. For polymer melts, thezero shear viscosity (ηo) and equilibrium recoverable compliance (Jeo) can be determined. Creep is a sensitivetechnique and best suited for the unmatched stress controlperformance of the AR. In a stress relaxation test, a strain isapplied and stress is measured as a function of time yieldingstress relaxation modulus G(t). Stress relaxation can be performed on all ARES and on the AR-G2 and AR 2000ex withdirect strain control.

APPLICATIONS

DYNAMIC OSCILLATION

ON LOW VISCOSITY FLUIDS

USING ARES

An advantage of the ARES design is that the motor generatesthe torque to overcome the viscosity of the material, as wellas the inertia of the sample holder. As a result, the ARES canbe used to conduct inertia free measurements on the viscoelastic properties of very low viscosity fluids. Figure 7shows an example of this for a polymer solution, where theviscoelastic parameters are determined using a frequencysweep up to 100 rad/s with no inertial effects.

AR-G2 NANO-TORQUE

MEASUREMENTS IN STRESS &STRAIN CONTROL OSCILLATION

The minimum torque on rheometer designs, which use onlyair bearings, is specified at a higher value for controlledstress (CS), as compared to controlled rate or strain (CR). The new magnetic thrust bearing and advanced drag cuptechnologies incorporated on the new AR-G2 allow for ultra-low, nano-torque control in both controlled stress and controlled strain modes. This unprecedented torque performance is shown in Figure 8. Note, viscosity and displacement values at instrument torque levels of 3 nN.m.

G'

G''

tan δ

tan

δ

log

G' a

nd G

" (Pa

)

temperature °C

1010

109

10

1

Glass transition Tg = 154.1°C

Temperature Ramp at 3°C/minFrequency = 1HzStrain = 0.025%

0.1

.01

108

107

106

105

-200 -150 -100 -50 0 50 100 150 200time (s)

Creep Zone: Stress > 0

Low η

High η Bad

Good

Recovery Zone: Stress = 0

stra

in

00

1400 10-1

101

100

10-3

10-2

10-1

10-4

100 101 102

freq [rad/s]

η*

(

) [P

a-s]

102

10-1

10-4

102

100

101

10-2

10-3

G“ (

) [P

a]G

‘ (

) [

Pa] 5.0

10-3 10-2 10-1 1 10 100

η* (

Pa.s

)

osc. torque (micro N.m)

disp

lace

men

t (ra

d)

15.0

10.0

7.5

2.5

0

12.5

10-7

10-6

10-5

10-4

10-2

10-1

3 nN.m

Controlled Stress Mode, CSControlled Strain Mode, CRNewtonian Model Fit; Newtonian Viscosity = 5.537

1000

10 0

10-3



-54- -55-

ARES

G2

AR

APPLICATIONS

EXTENSIONAL VISCOSITY

MEASUREMENTS ON ARES

Extensional viscosity is fundamentally important in manypolymer-processing techniques such as blow-molding, fiberspinning, and injection molding. The EVF is a polymer meltelongation fixture that transforms an ARES oven system intoa shear and extensional rheometer. The EVF uses a uniquepatented dual cylinder, or drum, wind-up technique. Figure 9shows the data on a LDPE sample, superposed with threetimes the shear and complex viscosity measured at a rate of0.01 1/s and frequency w = 1/t. The EVF clearly showsexcellent data over a wide range of rates.

10-2

10-1

100

101

102

102

103

104

Elon

gatio

n Vi

scos

ity [P

a.s]

time [sec]

105

106

1 s-10.3 s-10.1 s-10.03 s-10.01 s-110 s-13 s-130 s-10.003 s-13x complex viscosity3x shear viscosity at 0.001 s-1

STRESS AND SHEAR

RATE RAMPS

Stress and shear rate ramps are common transient experiments thatprovide fast and easy ways of characterizing yield stress and thixotropic behavior in materials. Both of these phenomena are typical time dependent behaviors of structured fluids that are important for understanding how a material will perform in an application. The stress ramp is a standard way of measuring yieldstress of a structured fluid. While ramping the stress linearly with time,the strain and instantaneous viscosity are recorded. It can be seen inFigure 10 that the viscosity increases initially and goes through a maximum. The stress value at the characteristic maximum in viscosityis a measure of the yield stress. Beyond this maximum, the material’sstructure breaks and the instantaneous viscosity decreases, or shearthins, with increasing stress. Rate ramps are more commonly used toobserve thixotropic behavior. A test procedure involving a shear rateramp from zero to a final rate and back to zero at constant rampingrate is referred to as thixotropic loop. The magnitude of the stress profile will be lower in higher in the up-ramp then in the down ramp.The area between the up and down stress curves as a function of rateis the called the thixotropic index.

max=1.363x104 [Pas]

y(t)=90.696 [Pas]

6000.0

5000.0

4000.0

3000.0

2000.0

1000.0

1.6x104

1.2x104

8000.0

4000.0

500.0

400.0

300.0

200.0

100.0

0.00.0

Time [s]

Visc

osity

η (t

) (Pa

.s)

Strain γ (t)

Stress τ (Pa)

80 100 120 140 160 180

STRESS GROWTH IN A TRANSIENT

STEP RATE EXPERIMENT

Transient viscosity and first normal stress coefficient measurements on a viscoelastic material in cone plate configuration are challenging rheological measurements. The instrument must have extremely low axial compliance inorder to minimize inward flows, which subsequently affect thenormal force. The ARES G2 uses a motor air bearing with highaxial stiffness and a non-compliant force rebalance transducerto reduce axial movement to less than 0.1µm/N. Figure 11shows results of a series of step rate experiments performedover a shear rate range from 0.1 to 100 1/s. It can be seenhere that the ARES-G2 can easily make these challenging measurements. Both transient viscosity and 1st normal stresscoefficient superpose well at short times at all shear rates. At longer times, the viscosity and normal stress coefficient tracesdiverge due to the non-linear material response at higher shearrates. The characteristic overshoot in both the viscosity and the1st normal stress coefficient is due to changes of the material’sstructure under strong shear fields.

100 [1/s]0.3 [1/s]1 [1/s]3 [1/s]10 [1/s]30 [1/s]

106

105

104

103

100

102

101

10-5

10-4

10-3

10-2

10-1

100

101

102

103

10-3

Time t (s)

Visc

osity

η(t)

(Pa.

s)

1st Norm

al Stress Coefficient Y

1 (t) (Pa.s2)

101 102100 10310-2 10-1

119.9 [Pa]0.03596 [Pa]

J(t) for Creep StressPIB 2490T=27.85˚CCreep Recovery

Slope: 0.9980

1.199 [Pa]0.1199 [Pa]3.596 [Pa]11.99 [Pa]35.96 [Pa]0.3596 [Pa]

100

10-1

10-2

10-3

10-4 10-4

10-1

10-2

10-3

100

10-2

Time t (s)

Com

plia

nce

J(t)

(1/P

a)

Recoverable C

ompliance J

r (t) (1/Pa)

101100 10210-1

CREEP AND RECOVERY OF A

VISCOELASTIC FLUID

Unlike oscillation, creep and recovery testing is well suited for measuringthe effect of long relaxation times (≥200 sec) on rheological behavior.The strain recovery also represents a very sensitive measurement of thematerial’s elasticity. In this experiment, a constant small stress is appliedto the sample and the resulting strain is measured with time. After asteady state flow has been reached, the stress is removed and the elasticrecoil of the sample is recorded. From the non-recoverable deformation,the material’s viscosity is determined. The recoverable deformation(recoil) provides the elastic component characterized by the equilibriumcompliance Je. Both AR-G2 and ARES-G2 are capable of performing thisexperiment. Accurate data determination of the materials elasticresponse requires overcoming inertial effects of the instrument at thecreep recovery transition. This is accomplished in AR-G2 using creepbraking, and in the new ARES-G2 using a novel approach of closing the control loop around the torque sensor. Critical to the recovery measurement are extremely low residual torques resulting from bearingfrictions in the AR-G2 design and torque sensor resolution in the ARES-G2 design. Figure 12 shows the creep and recoverable compliancefor the NIST standard reference PIB 2490 measured with the ARES-G2.The stresses used for these measurements range from 100 Pa down to aslow as 0.03 Pa. The superposition of the creep as well as the recoverablecompliance proves that conditions of linear viscoelasticity have been fulfilled at low stress. This type of data is unprecedented on a separatemotor and transducer instrument like the ARES-G2.



-57--56-

GEOMETRIES

TA Instruments offers a wide range of measurementgeometries including parallel plate, cone and plate,concentric cylinder, disposable, and torsion solidclamps.

Parallel plate and cone and plate geometries areavailable for both the ARES and AR Rheometers in anextensive variety of diameters and cone angles.Materials of construction include stainless steel, aluminum, plastic (Acrylic/PPS), or titanium.Disposable plates and cones are also available forapplications such as thermoset curing.

A wide selection of concentric cylinder geometries areavailable for both the ARES and AR Rheometers. Optionsinclude conical DIN, recessed, vaned, and double wall.For the ARES rheometers, the geometries are constructedof stainless steel and titanium. For the AR rheometers,stainless steel and anodized aluminum are used.

A variety of other geometries are available for both theARES and AR Rheometers, including clamps to measuresolids in torsion using the high temperature ovens andimmersion clamps. The ARES is available with many specialty fixtures including linear tack-testing fixtures,glass plates for optical measurements, and film/fiber fixtures.

NOTES


TECHNICAL SUPPORT

Customers prefer TA Instruments because of our reputation for

after-sales support. Our worldwide technical support staff is the

largest and most experienced in the industry. They are accessible daily by

telephone, email, or via our website. Multiple training opportunities are

available including on-site training, seminars in our application labs around the

world and convenient web-based courses.


Rheometers

TA INSTRUMENTS

-R2007C-ENG


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