3.3.4. Measurement of Viscosity
To characterize a polymer melt for replication processes, the knowledge of its viscosity is essential. The measurement of the viscosity under different temperatures and shear velocities allows one to obtain several points of the characteristic flow curves of a polymer melt. Three typical measuring systems are suitable: the measurement of the melt index, the capillary rheometer, and the rotation rheometer . The following sections will only describe the basics of these measurements.
22.214.171.124. Melt Index Measurement
The flow of a polymer can be characterized by the melt flow index (MFI). This value defines the mass of the melt that, in the span of 10 minutes, will be pressed through a defined nozzle by a piston. ...