Meltblowing: Multiple polymer jets and fiber-size distribution and lay-down patterns

In this work a comprehensive model of three-dimensional configurations of polymer jets in meltblowing from die exit to deposition screen is developed. In addition, multiple jets were modeled simultaneously, as well as deposition on a screen moving normally to the principal jet direction was accounted for. All important properties of polymer melts are used in the simulations, namely density, zero-shear viscosity and the viscoelastic relaxation time. In addition, the material parameters responsible for the temperature-dependent variation of the material properties are used. All the other parameters are the operational parameters characterizing gas flow. The results include prediction of the fiber deposition patterns and fiber-size distributions in the resulting nonwovens. The angular distributions in lay-down nonwovens are also predicted. Comparisons with the experimental data suggest that the model captures main trends rather accurately.