David Jon Pickard

US Patent:

39559513, May 11, 1976

Filed:

Jun 2, 1975

Appl. No.:

5/582574

Inventors:

Walter William Harris - Toledo OH
David Jon Pickard - Waterville OH

Assignee:

Johns-Manville Corporation - Denver CO

International Classification:

C03B 3702

US Classification:

65 1

Abstract:

Continuous inorganic fibers such as glass fibers are made by drawing molten material from orifices in the bottom of a refractory bushing. Occasionally during operation one or more tips will become clogged by unmelted particles in the molten material. These clogged tips will no longer produce a continuous fiber, but instead drip causing defects and breakouts which must be corrected. In the past, several methods have been tried to plug off these clogged tips, but none have been successful. The present invention involves a method of plugging a clogged tip while the bushing is at an elevated temperature using a small refractory plug. The present invention permits the bushing to be operated for its normal life thus producing a significant improvement in operating costs.