Capillary 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 stand 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.

NETZSCH capillary rheometers are essential whenever materials face high shear or elongational forces. 

Key application areas include:

• Polymer Melt Processing: Optimize extrusion, injection molding, fiber spinning, and blow molding processes by measuring viscosity, melt strength, and extensional behavior in order to prevent defects such as die swell or melt fracture.
• Plastics and Composites Development: Link molecular structure to flow properties, study the effects of additives, and characterize advanced materials (e.g., 3D-printing filaments and filled composites) under real processing shear rates.
• Paints, Inks, and Coatings: Simulate extreme shear during spraying, inkjet printing, and aerosol delivery to ensure stable flow, prevent clogging, and detect flow anomalies that rotational tests miss.
• Food Processing: Analyze the rheology of dough and mixtures under extrusion cooking conditions to optimize texture, flow through dies, and final product quality.

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 experience in rheometry, we have the best-suited instruments to help you.

All Rosand capillary rheometers come with the Flowmaster software package.

The NETZSCH Flowmaster software provides everything from standard shear viscosity measurements to advanced extensional analysis, process simulation, and thermal/mechanical stability evaluation, making Rosand rheometers highly versatile for both R&D and QC work.

Capabilities:

Comprehensive data acquisition and analysis for capillary rheology with multiple test types:

• Constant shear test
• Extensional test (using orifice die)
• Flow / no-flow tests
• Manual control mode

Advanced calculations and corrections:

• Bagley correction (orifice die & extrapolation methods)
• Rabinowitsch correction (for Non-NewtonianA non-Newtonian fluid is one that exhibits a viscosity that varies as a function of the applied shear rate or shear stress.non-Newtonian index)
• Hagenbach correction (fluid inertia)
• Cogswell convergent flow model for extensional viscosity

Additional analysis options (optional modules):

• Wall slip analysis (Mooney method)
• Melt fracture / flow instability detection
• Die swell measurement
• Material degradation & Thermal StabilityA material is thermally stable if it does not decompose under the influence of temperature. One way to determine the thermal stability of a substance is to use a TGA (thermogravimetric analyzer). thermal stability tests
• Low-speed degradation
• Eta-0 (intrinsic melt viscosity)
• 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 RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation measurements
• Low-level scripting for automated or custom routines

User-friendly features:

• Multi-language support
• Extensive help system
• Plotting & printing tools
• Direct data export for further processing

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. By carrying out measurements 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?

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 10 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.