METHOD OF MANUFACTURING HIGH STRENGTH GLASS FIBERS IN A DIRECT MELT OPERATION AND PRODUCTS FORMED THERE FROM

摘要

A method of forming high strength glass fibers in a glass melter substantially free of platinum or other noble metal materials, products made there from and batch compositions suited for use in the method are disclosed. One glass composition for use in the present invention includes 50-75 weight % SiO2, 13-30 weight % Al2O3, 5-20 weight % MgO, 0- 10 weight % CaO, 0 to 5 weight % R2O where R2O is the sum Of Li2O, Na2O and K2O, has a higher fiberizing temperature, e.g. 2400 - 2900° F (1316 - 1593 ° C) and/or a liquidus temperature that is below the fiberizing temperature by as little as 45 ° F (25° C). Another glass composition for use in the method of the present invention is up to about 64-75 weight percent SiO2, 16-24 weight percent Al2O3, 8-12 weight percent MgO and 0.25-3 weight percent R2O, where R2O equals the sum Of Li2O, Na2O and K2O, has a fiberizing temperature less than about 2650° F (1454 ° C), and a ?T of at least 80° F (45 ° C). A forehearth (12) for transporting molten glass from the glass melter (10) to a forming position is disclosed. By using furnaces and/or forehearths substantially free of platinum or other noble metal materials, the cost of production of glass fibers is significantly reduced in comparison with the cost of fibers produced using a melting furnace lined with noble metal materials. High strength composite articles including the high strength glass fibers are also disclosed.