Evaluation of Low Energy Cure Glass Fabric Prepregs

摘要

Low energy cure glass fabric prepregs were evaluated. These materials wereformulated to cure at low temperatures, from 140 deg F to 220 deg F, and under vacuum bag pressure. Several of these material systems are now commercially available and have potential applications in high quality, low cost fabrication of surface ship structures. Most of the prepreg resins are epoxy, but polyester and vinyl ester laminates were included in the evaluation. The test laminates were fabricated with a warps parallel lay-up and tested in tension, compression, flexure, and impact. Limited in-plane shear testing was done, particularly to assess the advantage of a quasi-isotropic vs. warps parallel stacking sequence. Thermal analysis was used to determine as-fabricated, post-cured, and moisture conditioned values of Tg. Single-sided prepreg and no-tack prepreg were identified as useful material forms for achieving low void content under vacuum bag pressure. The low cure temperature of the prepregs allows vacuum bag fabrication of sandwich panels with a variety of foam cores.