Rotational Rheometers

Yes!

The NETZSCH Kinexus rheometers are built on a legacy of excellence that dates back decades. Originally developed by Bohlin Instruments, pioneers in rotational rheology, the technology was later advanced by Malvern Instruments, who introduced the widely respected Kinexus platform. In 2020, NETZSCH Analyzing & Testing took over the full rheology product line from Malvern Panalytical, combining this proven technology with its own expertise in thermal analysis.

Adding rheometers to the NETZSCH portfolio both added significant value to our business and enabled our customers to benefit from a comprehensive product and application service. 

With this strong foundation, NETZSCH continues to deliver state-of-the-art rheometers that reflect decades of scientific innovation, precision engineering, and application know-how — and are trusted by researchers and industry leaders around the world.

Today, NETZSCH is home to both the Kinexus Prime series of rotational rheometers and the Rosand range of capillary rheometers. The service and support continue globally with monthly rheology webinars by both our rheology specialists and industry experts, comprehensive training courses, application materials and application rheology booklets. 

Our renowned comprehensive customer support and expertise sit alongside a world-class R&D team ready to bring new, innovative solutions to the world of rheology.

Read more about the history of our rheometers in these blog articles:

• 
  07.06.2022

  60 years of NETZSCH-Geraetebau: The Origins of Rheometry and its Flow Through Time

• 
  14.06.2022

  60 years of NETZSCH-Geraetebau: Rheology and its New Life at NETZSCH

There are two types of rheometers: rotational and high-pressure capillary. The main difference between the two is the applied shear rate. 

Why is it important to measure under different shear rates? We can build a picture of our materials, gaining insight on how formulation may influence rheology and in turn, affect processing and performance. How they behave at rest may be completely different from behavior during manufacture, transport, application or over time.

The shear rate, which is of great interest for rheological measurements, is dependent on the application. Spraying, for example, requires high shear rates; other applications, such as sedimentation, are associated with low shear rates. Accordingly, the choice of rheometer depends on the required shear rate. While the Kinexus, as a rotational rheometer, is the instrument of choice for measuring in the low shear rate range, a Rosand capillary rheometer would serve best for reaching high shear rates up to 1,000,000 s^-1.

NETZSCH is the only company on the market offering both types of rheometer; in combination with our other thermal analysis instruments, we are thus able to provide far-reaching analysis possibilities from a single source.
 

We perfect your processes: Which instrument matches your individual analysis needs?

Whether you need to measure the structure of a solid or determine performance when pumping, with over 14 decades of shear rate in rheometry, we have the best-suited instruments to help you. 
 

NETZSCH Rotational rheometers come with state-of-the-art rSpace, which is customizable to your specific needs. 

The intuitive rSpace software is easy to use. It offers over 200 built-in, customizable measurement sequences in 6 languages, including supporting application notes and educational tips.

The unique combination of Kinexus Prime hardware technology and rSpace software gives the user the ability to configure three critical rheometer functions independently:

• Rotational (shear) control: torque, speed and position
• Vertical (axial) control: gap and normal force
• Temperature control: IsothermalTests at controlled and constant temperature are called isothermal.isothermal, ramp or table
   

When performing viscosity measurements, the software can determine the steady state point, i.e. when the flow in the sample is no longer changing. This state can be detected directly by rSpace, which provides the characteristic value.

In oscillation tests, the harmonic distortion (clipping factor) can be easily outputted with a single click shortly before the sample is destroyed, which is very useful for quality control.

The rSpace software is driven by sequences – consisting of fundamental rheological actions (or test building blocks). These can be linked together with other test actions, to build intelligent tests. 

NETZSCH’s rSpace also includes an intuitive interactive guide during operation of the UV Curing (Crosslinking Reactions)Literally translated, the term “crosslinking“ means “cross networking”. In the chemical context, it is used for reactions in which molecules are linked together by introducing covalent bonds and forming three-dimensional networks.curing accessory.

Tips on how to select the appropriate measuring geometry: 

There is no hard-and-fast rule for selecting a geometry, as there are a number of factors which could come into play. But when considering a new sample and geometry selection, ask yourself first:

What is the general viscosity of my sample?

• If you have a water-like low viscosity, select a large diameter cone/plate or plate/plate geometry (>50 mm).
• If you have a free-flowing liquid (e.g., shower gel), a medium-sized geometry will work well (40 mm.)
• If you have a very stiff, thick sample (e.g., treacle), a small geometry should be selected (<40 mm).
• If you have a very low-viscosity or volatile sample, consider using a cup- and bob- or double gap. For evaporating samples, a solvent trap should be used.

Do I have particles in my samples?

• If the answer is yes, what size? The measuring gap should be at least 10 times larger than the largest particle size which can be changed for parallel plates.
• Cup- and bob-systems should also be considered, especially for settling samples where circulating grooved bobs are advantageous.

What is the composition of my sample?

• Is my sample prone to slippage? Emulsions or concentrated dispersions can slip on smooth geometries. Consider using a roughened or serrated surface finish for plates and a roughened or splined one for bobs.
• Does my sample have a delicate structure? A vane tool can be used on samples such as foams or soft solids for Yield StressYield stress is defined as the stress below which no flow occurs; literally behaves like a weak solid at rest and a liquid when yielded.yield stress measurements.
• Is my sample aggressive? Acidic samples can be measured with polymeric PEEK materials instead.

Start with these simple questions and review your results. The Kinexus provides extra information to give users confidence that they have selected the correct geometry. Its clever feature of being able to easily swap to a different geometry, along with automatic recognition, will make testing new samples fun and effortless.

Read the full tips and tricks article to learn even more: 

• Rheology – How to Select the Appropriate Measuring Geometry

Download also our geometry selection guide poster; see below.

• 
  NETZSCH_Rheology_Geometry-Selection-Guide.pdf

  (pdf – 1.65 MB)
• 
  Accessories for Kinexus Rheometers

  (pdf – 3.93 MB)

To be 100% on the safe side, please contact our NETZSCH expert team. We will be happy to find the best geometry for your needs!

The rheological analysis of samples is a fundamental part of developing many types of products. Unlike a viscometer, a rheometer can actually measure sample properties at extremely low shear rates, as in sedimentation, or at the high shear rates seen in pumping, mixing and application. In the correct shear range, we can adequately simulate a flow process and so differentiate good products from poor ones. The rheometer can also determine the effect of process changes, or adding different quantities of an additive, and so can be used to optimize the formulation and production of a product.

The rheometer not only measures the viscosity of the product at room temperature, but can also be used to evaluate the viscosity during a programmed temperature profile. This can also be used with polymers to evaluate processability and Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition temperatures. Results are accurate with minimal time spent testing, as a pre-programmed analysis may be started and left to run unattended, or even overnight.

Viscometry can be used to investigate the Yield StressYield stress is defined as the stress below which no flow occurs; literally behaves like a weak solid at rest and a liquid when yielded.yield stress, i.e. the StressStress is defined as a level of force applied on a sample with a well-defined cross section. (Stress = force/area). Samples having a circular or rectangular cross section can be compressed or stretched. Elastic materials like rubber can be stretched up to 5 to 10 times their original length.stress required to initiate sample flow, simulate a shearing process, measure shear stability or analyze how viscosity changes with temperature. Oscillation tests usually investigate the viscoelastic structure of a sample without breaking it down. Initially an amplitude sweep is run to determine how large an oscillation the sample can withstand before the structure breaks down, this is known as the Linear Viscoelastic Region (LVER)In the LVER, applied stresses are insufficient to cause structural breakdown (yielding) of the structure and hence important micro-structural properties are being measured.linear viscoelastic region. Once the Linear Viscoelastic Region (LVER)In the LVER, applied stresses are insufficient to cause structural breakdown (yielding) of the structure and hence important micro-structural properties are being measured.linear viscoelastic region has been determined, a frequency sweep, time sweep or temperature sweep may be performed to investigate how the viscoelastic structure and viscosity changes under dynamic conditions.

We know, that the decision as to whether to purchase a viscometer versus a rheometer is not always straightforward. The guide below will take you through the differences in greater detail and show the ways in which a rheometer may be better suited to your needs:

• 
  13.04.2023

  Viscometer or Rheometer – which is best for me?

The Kinexus platform is designed to be modular, meaning that any temperature control unit (TCU) will fit on any model.

Our Dynamic Shear Rheometer (DSR) series is especially designed for asphalt binder and bitumen testing. 

Download the catalog and datasheet here:

• 
  Kinexus Prime DSR Series

  Brochure

  (pdf – 2.08 MB)
• 
  Kinexus Prime DSR Series

  Data Sheet

  (pdf – 63 KB)

A rheometer can be configured according to sample type and application, with or without accessories. There are various models of both Kinexus Prime and Rosand, with bench-top and floor-standing options.

To get an accurate and up-to-date price for your personalized configuration, please contact your local NETZSCH representative or one of our authorized distributors. We will provide a quote tailored to your specific requirements, including any necessary training, installation, or additional features.

Our current delivery time is approximately 8 weeks, depending on the specific configuration of the instrument and current demand. For more complex customizations or during periods of high demand, the delivery time may extend beyond this range. 

For the most up-to-date information, we encourage you to contact us directly with a specific request. This will ensure that we can provide you with an accurate timeline tailored to your specific needs.