Extrusion plastometers deliver standard values of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastic materials under specified conditions of temperature and load. The MVR is normally useful when comparing filled and unfilled thermoplastics. According to ISO 1133 the relationship between two values of MFR (MVR) measured at different loads is called the flow rate ratio (FRR). It is commonly used as an indication of the way in which the rheological behavior is influenced by the molecular mass distribution.
Measurement Principle
The thermoplastic material which is contained in a vertical cylinder, is extruded through a die by a loaded piston. A high precision balance can be employed to determine the weight of the extruded filaments. | |
