Method and apparatus for forming glass fibers

The method of making a laminated wall for an inorganic fiber forming feeder comprising:

• supplying a refractory metal core;
• establishing a sheath made from a precious metal having a shape generally conforming to the shape of the core around said core;
• hot isostatically pressing said core and sheath to intimately bond the sheath to the core to form a laminate;
• providing at least one aperture through said laminate;
• inserting a first element in said aperture, said first element having a flange in abutting engagement with a side of said sheath, said first element having an orifice extending therethrough;
• inserting a second element in the orifice of said first element, said second element having a flange in abutting engagement with an opposite side of said sheath;
• providing a passageway through said second element adapted to permit molten inorganic material to flow therethrough;
• and
• sealing at least said first element to said sheath to protect said core from oxidation at elevated temperatures.

The method of forming glass fibers comprising:

• providing a feeder for supplying molten streams of inorganic material to be attenuated into fibers, said feeder comprising:
• a refractory metal core having an oxygen impervious, precious metal sheath intimately bonded thereto by hot isostatic pressing to form a laminate, said laminate having at least one aperture extending therethrough;
• a first element positioned in said aperture, said first element having a flange in abutting engagement with one side of said sheath and an orifice extending therethrough;
• a second element positioned in said orifice of said first element, said second element having a flange in abutting engagement with an opposite side of said sheath and a passageway adapted to permit said molten glass to pass therethrough;
• said first element being sealed to said laminate to prevent the oxidation of said core at elevated temperatures;
• and
• attenuating the streams of molten glass into fibers.