Abstract: An apparatus for draw forming glass filaments includes a melt furnace 1 having a bottom plate 12 with a plurality of flow holes therein, each terminating in a conical nozzle tip 2. Cooling fins 10 extend outwardly from a water pipe 11 and are disposed between the rows of tips, and additional cooling is provided at least during the initial start-up period by air blown across the nozzle tips from a manifold 13 disposed opposite the water pipe. With such an arrangement the flow hole diameters may be increased, which results in an exponential increase in the molten glass flow rate and filament production rate, while still achieving smooth initial and stable continuous filament forming conditions.

Abstract: An air flow supplied by a duct 10 adjacent a melt furnace 3 is normally directed downwardly through a plurality of nozzles 12 in the bottom of the duct towards a floor grate 13 or the like communicating with an exhaust duct 14, to thereby form a heat shielding air curtain 11 to protect the operator/controller. During the initial start-up period of the filament draw forming operation, however, a pivotal damper plate 15 adjacent the supply duct may be raised to deflect the air flow across the bottom of the orifice plate 4 of the melt furnace 3, to thereby cool the molten glass cones at the orifice exits and increase their viscosity, which serves to stabilize the filament forming conditions and prevent adjacent cones/filaments from converging together.