Under which circumstances does outgassing of foams occur and when does it need to be considered?
Outgassing can only occur in crosslinked PVC cores, i.e. the AIREX C70 / C71 range of products. AIREX R63 / R82 and AIREX C52 do not show this phenomenon. Outgassing is a result of excessive gas pressure in cells of the foam, which is built up during the production. The gas consists of Carbon dioxide, Nitrogen and some water vapour. This gas will slowly penetrate out of the foam. For normal sandwich production techniques the gas pressure in the cells does not cause problems. Some cases, however, need further considerations. In sandwiches produced in the prepreg process, or by bonding skins on the foam, outgassing needs to be considered. Furthermore, if sandwiches are exposed to high temperatures (e.g. dark coloured boat hulls in the sun), the foam needs to be properly treated before it is applied in the sandwich production process.
