Molecular dynamics simulation method applied to nanocavities replication via injection moulding

Injection moulding is a promising manufacturing process for obtaining cost-effective plastic parts with nanostructured surfaces. However, replication of nanocavities is not a straightforward method because the large heat transfer that takes place at the nanoscale tends to solidify the polymer before it has replicated all the cavities. This behaviour has been studied by different authors by means of Computational Fluid Dynamics simulations; in this way, factors such as process parameters (mould and melt temperatures, filling time, injection pressure limit, holding time, etc.) and geometric parameters (cavity geometry, cavities location in the mould, etc.) have been quantified. However, such investigations have found a roadblock when aiming to evaluate the replication of nanocavities with dimensions smaller than 100 nm. The reason is that the continuum hypothesis in which Computational Fluid Dynamics is based is not valid anymore. The purpose of this work is to overcome the scale limitation of Computational Fluid Dynamics and expose a Molecular Dynamics based algorithm to foresee the replication of nanocavities.