Apparatus for producing glass fibers

Apparatus for producing curly and straight fibers from a molten fiber forming material such as glass. A high velocity gaseous jet attenuates streams of the molten material into fibers. Before the fibers have completely hardened, a random curl may be imparted to the fibers as they pass through an elongated expansion nozzle, imparting turbulence to the gas stream. The degree of curl may be varied by parameter adjustments to the expansion nozzle. A pneumatic flip-flop may be incorporated into the gas expansion means for distributing the curled fibers on a collection surface.