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.
At least 30g of material are required.
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.
Equipment used at Plastics Technology Laboratories, Inc.:
Kayeness capillary rheometer
**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. For detailed procedures please contact a PTLI Technical Representative at firstname.lastname@example.org or obtain full and most recent revisions of the specific standard.
Plastics Technology Laboratories, Inc., 50 Pearl Street, Pittsfield, MA 01201. Tel: 413-499-0983; Fax: 413-499-2339.