An aqueous glass fiber sizing composition that includes a polymeric film
forming component, at least one silane coupling agent, and one or more
lubricants is provided. The polymeric film forming component of the
sizing composition includes a silanated polyvinyl acetate, an epoxidized
polyvinyl acetate, and a modified epoxy emulsion. In preferred
embodiments, the film formers are present in the sizing composition in
ratios of 70:25:5, 50:25:25, or 63:18:18 of silanated polyvinyl acetate,
epoxidized polyvinyl acetate, and modified epoxy emulsion respectively.
Fibers sized with the sizing composition in a sheet molding compound
process have improved wet-out characteristics.