Meaning
Standardization protocols measure the ease of flow of molten thermoplastic polymers under specified thermal and load conditions. Quality departments use melt flow rate iso 1133 to characterize incoming resin batches and ensure that flow properties are consistent. This measurement provides the baseline viscosity data required for setting up injection molding machine parameters.
Testing Procedure
Polymeric materials are heated in a standardized barrel and extruded through a defined capillary die using a specified piston weight. Under melt flow rate iso 1133, the mass of plastic extruded over a set period is measured to calculate the flow index. This test requires strict control of moisture levels in the resin, as damp polymers can undergo hydrolytic degradation during heating, causing inaccurate flow readings and erroneous viscosity assessments.
Molding Application
Viscosity values determine how easily a resin can fill thin-walled cavities. Deviations from the melt flow rate iso 1133 specification can lead to defects such as short shots. Molders adjust temperatures to compensate for variations.
Resin Verification
Tracking changes in flow index allows processors to detect material degradation from excessive use of recycled regrind. A significant rise in the melt flow rate iso 1133 value indicates polymer chain scission and a drop in final part impact strength. This verification helps protect the mechanical integrity of critical molded plastic products.
