Development and Evaluation of FRP Sandwich Beams Containing Glass Fibers Into Phenolic Foam Core

Abstract

Phenolic resin has excellent properties of fire resistance, low smoke during burning, and it also has a good balance between its cost and mechanical properties compared with other types of resin used in FRPs. If phenolic resin can be employed as a matrix of FRP, such FRP can have a higher fire safety factor which will be a desirable property in the structures of vessels and railway carriages. However, for the case of the resole type of phenolic resin, water due to condensation reaction remains in the matrix, and this water evaporates resulting in the formation of voids during curing process. In order to develop a new type of phenolic composite that be able to overcome this weakness, we used a foam type of phenolic resin and glass fibers as the matrix and as the reinforcement, respectively. We then developed a new pultrusion technique for the new composite, namely the phenolic foam composite (PFC) and examined its mechanical properties and thermal conductivity. In this paper, we reported a new technology to mold not only a phenolic foam composite but also a sandwich beam in which the PFC as a core and a thin phenolic GFRP or CFRP as facelayers were used. We also examined thermal and bending properties of this sandwich beam.