Slide 3 of 18
This is a schematic diagram of how sizings are applied in a continuous filament fiberglass operation. Several hundred to several thousand fibers are pulled from a bushing. The fibers are accelerated from a velocity of about 2 cm per minute to 2 km per minute or more over a distance of about 2 cm. Water is sprayed onto the fibers between the bushing and the sizing applicator to reduce static build up and to cool the fibers. The time required for the fiber to travel from just below the bushing to the sizing applicator is typically 1-2 ms. The sizing is applied in a few micro seconds as it passes over a carbon roller that has a film of sizing on it. A few milliseconds later and the fibers are gathered together in a strand and wound on a tube or chopped. The sizing performs several functions, one of which is to aid in allowing the fibers to come into close contact but not damage the fiber surface. This function plus the adherence of the molecules which form the “glue” between the glass and the polymer must take place in 1 ms or less. What we would like is for molecular modeling to give us some insights as to the chemical reactions that are going on at and near the glass surface.