Smithers regularly provides a rheology service to support quality control processes, assist with failure analysis and process optimisation issues. The information obtained can provide accurate materials property data for flow simulation software packages such as Moldflow, Sigmasoft 3D and Compuplast.
Our rheological capabilities
Rheology for plastics
Smithers can generate rheological data all the way through from simple Melt Flow Index (MFI), to low shear rate, high shear rate and finally, to in-line die rheology on an extruder.
Melt Flow Index/Rate (MFI/MFR)
- Typically used as a basic quality control tool.
- Useful for checking whether the polymer grade is as specified, especially if processing problems are occurring.
- Oscillating disc rheometry is a more powerful technique than MFI.
- It can provide information on molecular weight distribution that can be used for processing, thermal stability or degradation studies.
- Rotational rheometry is also used for the assessment of changes in viscosity as a function of temperature or shear rate.
- Measures viscosity at shear rates typical of those used in polymer processing, such as extrusion or injection moulding.
- Can show the difference between polymers with similar MFI’s but different molecular weight distributions.
- Measures viscosity at a range of temperatures to help optimise processing conditions.
Rheology for rubbers
Our service for rubbers covers simple cure characteristics and sophisticated rubber processing analysis.
Cure properties (MDR)
- This instrument is in almost constant use in our processing lab. It is used to assess cure kinetics and offer a quality control solution.
- Variable temperature cure analysis.
- Can also be used for assessing cross-linkable polymers as well as rubbers.
Rubber Proccessing Analysis (RPA)
- More sophisticated than MDR.
- Can be used to assess the processing of rubbers in a similar way to oscillating disc Rheometers for plastics. Provides information useful for extruding rubber compounds.
- Can also be used for assessing polymers such as PVC.
Thermoset cure measurement
- The Scanning Vibrating Needle Curemeter (SVNC) can be used to quantify the values of cure for many thermosetting materials, mastics and adhesives. More details can be found here.
Find out more by contacting one of our experts.