Patent GB-931869-A (GB)
Title: Method and apparatus for forming continuous filaments of glass and like heat-softenable material
IPC: C03B37/04
Filed: 1960-08-09
Abstract: 931,869. Forming glass filaments. OWENS-CORNING FIBERGLAS CORPORATION. Aug. 9, 1960 [Aug. 12, 1959], No. 27586/60. Class 56. In the formation of glass and like continuous filaments, the material, which may be molten glass or, more particularly, glass cullet in finely divided form, is fed on to a platform in a rotor, distributed from the platform by centrifugal force on to a wall of the rotor which is heated to maintain a melt of the material in the rotor, the rotor being rotated to project the molten material from orifices in the wall in the form of streams which are attenuated into continuous filaments, the material flowing down the wall to the orifices which are disposed below the level of the platform. As shown in Fig. 2, a rotor 44 has a cylindrical wall 46, bottom 48, top outer flange 52 and inner flange 50 to retain and prevent further rising of the molten glass. The rotor 44 is joined by a collar 54 to a hollow sleeve 36 driven by pulley 70 and belt 72 from a motor supported on the main frame 12. Finely divided granular glass cullet M is supplied from a hopper tube 88 through a stationary guide tube 76 disposed within the rotating sleeve 36 and cooled by fluid circulating in an annular chamber 80 surrounding the tube. The hopper is provided with means for controlling the rate of feed of the material M to the rotor comprising a feed drum with radially arranged vanes between the hopper and the discharge tube 88. The material M falls through tube 76 on to a distributer platform 106, joined to the wall 46 by struts 108 to rotate therewith, which projects the material on to the wall 46 near the upper part of the wall. An induction heating coil 110 surrounds the wall 46 between the distributer 106 and rows of orifices 49 and melts the material M which is projected from the orifices 49 in the form of filaments F which are twisted by the rotor to form a yarn 122 which may be collected on a roating mandrel to form a wound package. The lower part of the rotor 44 may be surrounded by a further induction heating coil 166 to maintain the material adjacent the orifices 49 in the molten condition. To assist collection of the filaments F, hot air is projected downwardly adjacent the rotor 44 from an annular plenum chamber 132 supplied with air from a blower via conduit 140 which is heated by electrically energized strips 142 in a chamber 136, the air, heated to about 500 F., being directed towards the wall 46 through orifices 150 and downwardly through orifices 148. The heated air is confined by a cylindrical shield 168. Further air, heated to a lower temperature, is projected downwardly from an annular plenum chamber 155 surrounding the chamber 132 having baffles 160 and a plurality of orifices 164. In a modification, not shown, the chamber 155 is positioned lower so that its inner wall acts to confine the heated air from the inner chamber 132 and the chamber 155 is divided by an annular partition to form two chambers, the outer one providing air at room temperature. In a modification of the rotor 44, not shown, the wall 46 is given a slight outward, downward slope and the bottom wall is replaced by a cone-shaped cap to reduce turbulence below the rotor. As shown in Fig. 4, the rotor 170 comprises a cylindrical wall 172 with rows of apertures 176 and a central column 178 supporting a distributer platform 180. In addition to the heating coil 110a, the molten glass inside the, rotor is heated by a combustible mixture ignited at the outwardly curved end 184 of a tube 182 extending into the rotor, to assist in maintaining the film of material in flowable condition.