Capillary Rheometry Shear Sweep, Thermal Stability ASTM D3835, ISO 11443

Capillary Rheometry measures apparent viscosity (resistance to flow) over a broad range of shear rates and at varied temperatures, which are comparable to the conditions encountered in molding, calendaring, extrusion, etc. The data is commonly used to determine processing parameters, for lot-to-lot quality control, to measure processing degradation, which could reduce physical properties, and to study thermal stability.

Test Procedure:
According to customer specifications, temperature, shear rate and other parameters are selected. In a Shear Sweep melted plastic is extruded through a capillary and the force at varied shear rates is determined. To determine Thermal Stability, melted plastic is extruded through a capillary after varied periods of residence time in the barrel of the extruder.

Specimen size:
80g of material

In a Shear Sweep, shear stress and shear rate are calculated and plotted.
For Thermal Stability, apparent melt viscosity is calculated and plotted versus residence time.

**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. For more information please contact an Intertek Technical Representative at Due to copyright restrictions, we are not able to provide copies of standards. Standards can be obtained from appropriate standards authorities.

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