Abstract: A method of producing glass fiber comprising: driving a bottomed hollow cylindrical rotor to rotate at high speed around a vertical rotary shaft, said rotor comprising a bottom, a peripheral wall and an annular flange, said peripheral wall being extended upwardly from an outer peripheral edge of the bottom and provided with a large number of fine holes, said annular flange extending inwardly from an upper edge of the peripheral wall; falling molten glass to the bottom of the rotor; and ejecting molten glass through said fine holes by centrifugal force generated by the high speed rotation of the rotor, to form the molten glass into filaments, and to produce glass fiber; characterized in that molten glass is made to fall at a position on the bottom, said position being apart from an inner edge of said annular flange by at least 10 mm or more, and apart from an inner surface of said peripheral wall by not more than 75 mm, the bottom having a large thickness at the position.

Abstract: It is therefore an object of the present invention to provide a method and an apparatus for continuously producing high quality glass fiber that shows excellent characteristics required to various glass fiber products in terms of fiber length, fiber quality and fiber distribution and, at the same time, that allows to prolong the service life of the rotating body, that improve the productivity, and that suppress any increase in the producing cost. An axial and/or circumferential rows of orificeless sections are provided in a peripheral wall of a hollow rotating body. Also, a gas flow is provided around a flame flow, and a compressed gas flow are also provided.

Abstract: A glass composition improves the bio-solubility (solubility to physiological salt water), and is suitable for manufacturing inorganic fiber and a molded product of such inorganic fiber. The glass composition to be used for manufacturing inorganic fiber is characterized by containing SiO2 by 52 to 72 wt %, Al2O3 by less than 3 wt %, MgO by 0 to 7 wt %, CaO by 7.5 to 9.5 wt %, B2O3 by 0 to 12 wt, BaO by 0 to 4 wt %, SrO by 0 to 3.5 wt %, Na2O by 10 to 20.5 wt %, K2O by 0.5 to 4.0 wt % and P2O5 by 0 to 5 wt %. The raw material of the glass composition contains cathode ray tube glass and/or liquid crystal glass by 0 to 50 wt %.

Abstract: A method of producing glass fiber comprising: driving a bottomed hollow cylindrical rotor to rotate at high speed around a vertical rotary shaft, said rotor comprising a bottom, a peripheral wall and an annular flange, said peripheral wall being extended upwardly from an outer peripheral edge of the bottom and provided with a large number of fine holes, said annular flange extending inwardly from an upper edge of the peripheral wall; falling molten glass to the bottom of the rotor; and ejecting molten glass through said fine holes by centrifugal force generated by the high speed rotation of the rotor, to form the molten glass into filaments, and to produce glass fiber; characterized in that molten glass is made to fall at a position on the bottom, said position being apart from an inner edge of said annular flange by at least 10 mm or more, and apart from an inner surface of said peripheral wall by not more than 75 mm, the bottom having a large thickness at the position.

Abstract: It is therefore an object of the present invention to provide a method and an apparatus for continuously producing high quality glass fiber that shows excellent characteristics required to various glass fiber products in terms of fiber length, fiber quality and fiber distribution and, at the same time, that allows to prolong the service life of the rotating body, that improve the productivity, and that suppress any increase in the producing cost. An axial and/or circumferential rows of orificeless sections are provided in a peripheral wall of a hollow rotating body. Also, a gas flow is provided around a flame flow, and a compressed gas flow are also provided.

Abstract: A glass composition improves the bio-solubility (solubility to physiological salt water), and is suitable for manufacturing inorganic fiber and a molded product of such inorganic fiber. The glass composition to be used for manufacturing inorganic fiber is characterized by containing SiO2 by 52 to 72 wt %, Al2O3 by less than 3 wt %, MgO by 0 to 7 wt %, CaO by 7.5 to 9.5 wt %, B2O3 by 0 to 12 wt, BaO by 0 to 4 wt %, SrO by 0 to 3.5 wt %, Na2O by 10 to 20.5 wt %, K2O by 0.5 to 4.0 wt % and P2O5 by 0 to 5 wt %. The raw material of the glass composition contains cathode ray tube glass and/or liquid crystal glass by 0 to 50 wt %.

Abstract: A process for forming glass filaments by utilizing centrifugal force, in which compressed gas is injected from a position near an interior of a flame port frame of a fiberizing burner toward a throat portion of a discharge port of the burner at an acute angle relative to the direction of discharge of a flame stream from the discharge port, so that the compressed gas is mixed with combustion exhaust gas at an inlet portion of the throat portion, and the mixed gas is injected from the discharge port of the burner in a direction generally parallel to the direction of the generatrix of the outer peripheral surface of the peripheral wall, thereby forming primary filaments into fine secondary filaments.