Investigation of a Finite-Difference-Method based real-time viscous heating compensation in a nozzle viscometer for inline viscosity measurement of phenol resins

Abstract

This work is motivated by the rarely available material data for thermosets and a missing inline viscosity measurement method to monitor melt property deviations. A nozzle viscometer is designed for inline viscosity measurement of phenol-formaldehyde compounds. The nozzle viscometer is mounted at the plasticizing unit of an injection molding machine. A fluid coolant circuit allows a dynamic tempering to pause the transient crosslinking reaction. A 2D FDM model is implemented, to calculate the viscous heating within an injection cycle and to compensate the temperature rising effect in the viscosity measurement. The FDM model processes the inline sensor signals in a closed loop correction in real time to determine a corrected reactive viscosity model. The signal-to-noise-ratio quantifies the reliability of the inline viscosity measurement method.

Keywords

• Thermoset injection molding
• Phenolic resins
• Inline rheometer
• Nozzle viscometer
• Slit die
• FDM model