Epoxy resin system and pultrusion process employing same

A pultrusion process for the production of fiber-resin composite which comprises:

• creeling a plurality of fabric bands,
• collating said creeled bands to align same and form an array of closely spaced but separated bands,
• passing said array of collated bands through a heated epoxy resin system in a wet-out tank to wet and impregnate said array, said system comprising a tris (hydroxyphenyl) methane based epoxy resin and a combination of the cross-linking agents (methyl)bicyclo (2,2,1) heptane-2,3-dicarboxylic anhydride and poly sebacic poly anhydride, and a small amount of an imidazole accelerator, the ratio of said respective cross-linking agents to the total amount of cross-linking agents, and the total amount of cross-linking agents to resin, being effective to provide a resin system having a pot life of at least 3 hours at 70.degree. C., a cure rate of less than 3 minutes at elevated temperature, and a viscosity profile less than 2500 cps at 70.degree. C. and greater than 100 cps at 120.degree. C.,
• passing said wetted and impregnated array of fabric bands through a forming guide which forms said last mentioned array into a resin impregnated laminate,
• passing said laminate through a heated pultrusion die, the rate of passage of said laminate through said die being sufficient to cure the resin in said laminate during said passage, and
• discharging a continuous length of cured fiber-epoxy composite from said die.