Characterization of membranes used in pressure driven composite processing

Nano-porous membranes are being used in the Vacuum Assisted Process (VAP) as a surface fluid barrier layer that provides continuous venting, reduced void content and improved process repeatability. A model to describe the membrane/resin interactions as a function of microstructure and constituent properties was presented in previous work. It enables the prediction of barrier characteristics, especially permeability, as a function membrane microstructure and process pressure. In this paper, we fully characterize six EPTFE candidate membranes for VAP. Membranes are characterized using SEM and porometry to establish pore size distributions and their corresponding Weibull fits. We will also present the permeability results for the different materials, based on our previous findings, and use this information to provide a ranking of the membranes based on their pressure capability for processes of interest.