It's with considerable excitement that we're able to announce the start of the resin testing phase of our materials R&D programme "Composite Materials for Marine Renewables". In addition to the exotherm tests already completed, our objectives call for measurement of the density and moisture absorption characteristics of cast resin specimens.
The method for establishing the density of cast resin specimens is a particular favourite: This beautifully simple test exploits the principle of displacement first identified by Archimedes over 2000 years ago: Hard to be certain, but he seems reasonably impressed with our efforts! Measurement of cured resin density will in due course enable us to estimate the fibre volume fraction (Vf) of our laminates.
Having taken advantage of the density check, the resin specimens are choosing to 'self isolate' in our moisture conditioning unit. One specimen of each of 10 resin types is placed in seawater whilst the other is held in de-ionised water, in both cases at a steady 45 Celcius: Here they will stay until regular weight measurements show that they have become moisture-saturated. We believe that the moisture absorbed by the resin has a significant effect on laminate strength, so although simple, these tests form a key part of our overall strategy.