Webinar: Mixer Test – A Versatile Tool for Polymer Processing

Editor’s Note: This is the fourth of a five-part webinar series on general extruders and mixers for characterizing and formulating your polymer materials using rheology, viscometry, mixing and extrusion technologies. Watch for a webinar every Tuesday in March.

A modular torque rheometer can be equipped with different measuring sensors such as mixers, single– or twin screw extruders. Simulating industrial polymer processing on a laboratory scale, relevant process parameters such as temperature, pressure and screw speed are measured and help to understand and optimize the respective system.

Laboratory mixers are used in the lab for testing and material characterization. Typical applications include:

Testing the melting and degradation behavior of polymer melts
Quantifying viscosity when adding nano particles or other additives
Testing gelation and plastification behavior of PVC dry-blends
Measuring the flow and curing behavior of thermo setting plastics
Characterizing the influence of different additives such as carbon black, fillers lubricants, accelerators and sulfur for rubber mixtures
Measuring the stable torque in regard to individual and combined influences of fillers and additives such as stabilizers, lubricants and color pigments
Testing polymer mixtures of high performance plastics to check processability
Performing electric conductivity measurements for rubber mixtures
Recording the vulcanizing behavior of elastomers

A typical mixer test is run at a defined rotor speed (shear rate). The material’s response to the shear is recorded as torque and displayed versus time. A material’s properties are very sensitive to temperature and to get the best results should be separated into different sections in a mixer chamber. These are individual temperature-controlled by the rheometer system. The recorded “Rheogram” (torque and melt temperature vs. time at constant speed) is characteristic for different material types and blends. The mixer test is used as a fingerprint in quality control for outgoing and incoming product inspections.

We’ve created a 25-minute webinar that covers the structure and applications for torque rheometers and measuring mixers, including measuring mixers for routine monitoring and production of small sample batches. Anyone involved with quality assurance, development and testing of polymer compounds and rubber mixtures as well as their processing will learn how to interpret measuring curves in terms of gelatinization and plastification behavior. In addition, we will discuss vulcanization and curing times, network behavior, thermal stability testing, absorption capacity, processing characteristics, and processability.

Click here to watch the Webinar: Mixer Test – A Versatile Tool for Polymer Processing

Here are links to the full series: