Manufacture of Thick Cross-Section Composites Using a Pre-Catalyzed Fabric Technique

Abstract

The development of a technique is reported for the manufacture of thick unsaturated polyester matrix resin composites using pre-catalyzed glass fabric. Composites over 2 cm thick using glass fabric that was pre-catalyzed (sized) with benzoyl peroxide were compared to composites made using conventional premixed catalyst and resin compounds. The pre-catalyzed fabric is shown to result in reduced internal temperatures during curing. This allows for the construction of thick fiber reinforced composite materials that do not suffer thermal degradation during the curing process. Mechanical testing of prepared thick composites demonstrated that the pre-catalyzed glass fabric composites were significantly stronger than conventionally prepared composites. The center regions of pre-catalyzed composites were about 80% stronger under tension, 25% stronger in compression and 35% stronger under shear than those of conventionally prepared composites of the same thickness. The pre-catalyzed composites were also more uniformly consolidated. Previous work aimed at the manufacture of thick composites has utilized controlled curing by use of expert systems, local resistance heating within the composite or the addition of chemical inhibitors. A method for staged curing has also shown considerable promise. None of these methods, however, has enabled high volume production of high quality thick composites. This paper presents the results of a new method for manufacture of thick composites based on a pre-catalyzed fabric technique.