By T.Kealy
Technical Manager - Rheology Solutions Pty Ltd

Polymer processing includes unit operations such as compression, injection and blow moulding and extrusion through a variety of dies. Specifically for the polymer industries, materials characterisation is of critical importance (including fluid related issues like sedimentation, time related structural decay or build-up and post-cure issues like strength of compression or extension) for prediction and management of sharkskin, melt fracture, calendering, die swell, melt homogeneity and short- and long-term dimensional stability of extrudates or moulded parts. These processes depend on fluid rheological parameters such as viscosity, visco-elasticity, creep and recovery, and solid material properties such as behaviour under various compressive and extensional loading conditions. Extensional flow properties dominate processes where stranding occurs and influences time, quality and energy requirements.

The Rheology Solutions applications laboratory has state of the art equipment, capable of measuring all of the above parameters, and of providing interpretation of the results where necessary. Laboratory equipment includes highly sensitive, specialised, modern instrumentation and sensor systems, for measuring complex or difficult fluids such as those with very low viscosity, or those with a highly settling solid phase, or liquids with significant extensional or visco-elastic properties. Solid material properties according to various international standards can also be monitored.

Information such as shear viscosity curves, thixotropic behaviour and flow curves may be obtained for interested clients. Additionally, of importance to the industry, when scientifically assessing changes in flow behaviour due to temporal or ingredient issues, viscoelastic moduli as a function of temperature (up to 250°C) shear rate or strain can be assessed. Structural changes under very low shear (like in the case of storage, gravity settling, compression moulding etc) or very high shear (pumping, extrusion, mixing, injection moulding etc) are possible using the advanced equipment and sensors available at the laboratory of Rheology Solutions. These measurements may be obtained as a function of temperature, solids density, or to monitor the effects of changes in additive/ingredient species or concentration.

With this information the scientist or engineer may change the process, or design new unit operations or products to maximise the potential benefits to be obtained from the physical properties of the processed fluid.

Rheology Solutions is pleased to provide this information to interested parties, and to make our rheological expertise available to the polymer processing community. Our range of testing and interpretation services is further supported by customised workshops, training and seminars to cover the needs of individuals, businesses or industry sectors, covering introductory, intermediate or advanced theory and practice of rheology. This can be supplemented by application specific workshops.

A complete Contract Testing Information Kit specific to the Polymer Processing Industry is available by sending an email to info@rheologysolutions.com and typing "Contract Testing Kit for the Polymer Processing Industry" in subject area. You should receive your kit via post within 5-10 working days.

The Contract Testing Request Form needs to completed and returned prior to any samples being sent. This will allow us to advise you within 48 hours if we require further information. We will then provide an overview of the work we will carry out including an estimate of the projected time scale and associated fee.

For further information, please complete the Information Request Form.

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