Challenges when using cure kinetic models online


How our technology compares to the use of kinetic models online

Kinetic models are being used to model the cure behaviour of reactive resins mainly to fill the need for cure simulation and optimisation during the process design phase. However, sometimes kinetic models are used also in real-time to estimate online the degree of cure by simply measuring the process temperature.

This is a good idea if only the temperature is being monitored and a reliable kinetic model for the specific resin exists.

However we need to have in mind the various limitations such as:

  • Kinetic models depend only on (measuring) temperature so resin or batch-to-batch deviations cannot be accounted for
  • Significant resources and knowledge are necessary to develop new kinetic models
  • Kinetic models are strongly inaccurate:
    • in non-isothermal cases
    • outside their development range
    • in their calculations from degree of cure to Glass Transition temperature
    • because of their integral nature all errors are added towards the end of cure.

Kinetic models have questionable accuracy even for well established and extensively studied aerospace resins. For example in the well known RTM6© epoxy resin from Hexcel© several kinetic models have been proposed which have significant differences between them. So for less popular resins a lot of effort and cost is necessary to develop a kinetic model with questionable accuracy in practice.