The flow of thermosets through the nozzle of an injection molding machine

The conservation equations of momentum, energy, and mass are numerically solved for the flow of thermosets through the nozzle of an injection molding machine. The following working hypotheses are stated: perfect mixing of reactants, validity of the lubrication approximation, steady state (based on previous results for thermoplastic materials), negligible diffusional mass transfer, adiabatic boundary condition, and wall slip. Numerical results for a particular case-show that the value of the slip friction coefficient is very important for defining the process feasibility. The apparent viscosity of the material is also relevant to the process. Materials of low viscosity gel at the wall of the nozzle inlet section; high viscosity materials may gel at the outlet section, requiring great pressure gradients and showing high wall temperatures at the exit. These high temperatures may cause degradation or undesirable side reactions.