Glass fiberization method

Claim 1

A method for centrifugally producing glass fibers from a glass composition as follows: ______________________________________ SiO.sub.2 61 to 72% Al.sub.2 O.sub.3 2 to 8% Fe.sub.2 O.sub.3 0.2 to 1% CaO 4.7 to 7.5% MgO 0 to 5% Na.sub.2 O + K.sub.2 O 14 to 18% B.sub.2 O.sub.3 0 to 6% F 0 to 1.5% BaO 0 to 2.5% ZrO.sub.2 0 to 2.5% Misc ≦1% ______________________________________ said method comprising the steps of introducing the glass in molten attenuable condition into a spinner for delivery to the interior surface of the peripheral wall thereof, said peripheral wall having a multiplicity of orifices therein, rotating said spinner to effect the centrifugal delivery of the glass through the spinner orifices in a multiplicity of streams, and attenuating said glass streams into fibers by means of an internal combustion burner providing a generally downwardly directed annular gaseous blast adjacent the exterior of said peripheral wall, said gaseous blast having an elevated temperature contributing to the maintenance of the glass streams in attenuable condition for a time sufficient to effect attenuation thereof, and wherein centrifugal acceleration at the spinner wall, the diameter of the spinner, the peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ centrifugal acceleration 4000 m/sec.sup.2 to 20,000 m/sec.sup.2 ______________________________________ Spinner diameter 550 mm to 1500 mm peripheral velocity 50 m/s to 130 m/s burner pressure 100 mm to 900 mm (water column). ______________________________________

Claim 2

A method for centrifugally producing glass fibers from a glass composition as follows: ______________________________________ SiO.sub.2 61 to 72% Al.sub.2 O.sub.3 2 to 8% Fe.sub.2 O.sub.3 0.2 to 1% CaO 4.7 to 7.5% MgO 0 to 5% Na.sub.2 O + K.sub.2 O 14 to 18% B.sub.2 O.sub.3 0 to 6% F 0 to 1.5% BaO 0 to 2.5% ZrO.sub.2 0 to 2.5% Misc ≦1% ______________________________________ said method comprising the steps of introducing the glass in molten attenuable condition into a spinner for delivery to the interior surface of the peripheral wall thereof, said peripheral wall having a multiplicity of orifices therein, rotating said spinner to effect the centrifugal delivery of the glass through the spinner orifices in a multiplicity of streams, and attenuating said glass streams into fibers by means of an internal combustion burner providing a generally downwardly directed annular gaseous blast adjacent the exterior of said peripheral wall, said gaseous blast having an elevated temperature contributing to the maintenance of the glass streams in attenuable condition for a time sufficient to effect attenuation thereof, and wherein centrifugal acceleration at the spinner wall, the diameter of the spinner, the peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ centrifugal acceleration 4000 m/sec.sup.2 to 20,000 m/sec.sup.2 ______________________________________ Spinner diameter 550 mm to 1500 mm peripheral velocity 50 m/s to 130 m/s burner pressure 100 mm to 900 mm (water column). ______________________________________

Claim 5

A method for centrifugally producing glass fiber insulating blanket from a glass composition as follows: ______________________________________ SiO.sub.2 61 to 72% Al.sub.2 O.sub.3 2 to 8% Fe.sub.2 O.sub.3 0.2 to 1% CaO 4.7 to 7.5% MgO 0 to 5% Na.sub.2 O + K.sub.2 O 14 to 18% B.sub.2 O.sub.3 0 to 6% F 0 to 1.5% BaO 0 to 2.5% ZrO.sub.2 0 to 2.5% Misc ≦1% ______________________________________ said method comprising the steps of introducing the glass in molten attenuable condition into a spinner for delivery to the interior surface of the peripheral wall thereof, said peripheral wall having a multiplicity of orifices therein, rotating said spinner to effect the centrifugal passage of the glass through the spinner orifices in a multiplicity of streams, and attenuating said glass streams into fibers by means of an internal combustion burner providing a generally downwardly directed annular gaseous blast adjacent the exterior of said peripheral wall, said gaseous blast having an elevated temperature contributing to the maintenance of the glass streams in molten condition for a time sufficient to effect attenuation thereof, wherein the spinner diameter, the centrifugal acceleration at the spinner peripheral wall, the peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ spinner diameter 550 mm to 1500 mm centrifugal acceleration 4000 m/sec.sup.2 to 20000 m/sec.sup.2 peripheral velocity 50 m/s to 130 m/s burner pressure 100 mm to 900 mmm (water column) ______________________________________ thereby producing fibrous insulation blanket having the following characteristics: ______________________________________ fineness 2(5 g) to 5(5 g) micronaire conductivity 30 × 10.sup.-3 to 55 × 10.sup.-3 (W/m °K.) density 8 to 75 (Kg/m.sup.3). ______________________________________

Claim 6

A method for centrifugally producing glass fiber insulating blanket from a glass composition as follows: ______________________________________ SiO.sub.2 61 to 72% Al.sub.2 O.sub.3 2 to 8% Fe.sub.2 O.sub.3 0.2 to 1% CaO 4.7 to 7.5% MgO 0 to 5% Na.sub.2 O + K.sub.2 O 14 to 18% B.sub.2 O.sub.3 0 to 6% F 0 to 1.5% BaO 0 to 2.5% ZrO.sub.2 0 to 2.5% Misc ≦1% ______________________________________ said method comprising the steps of introducing the glass in molten attenuable condition into a spinner for delivery to the interior surface of the peripheral wall thereof, said peripheral wall having a multiplicity of orifices therein, rotating said spinner to effect the centrifugal passage of the glass through the spinner orifices in a multiplicity of streams, and attenuating said glass streams into fibers by means of an internal combustion burner providing a generally downwardly directed annular gaseous blast adjacent the exterior of said peripheral wall, said gaseous blast having an elevated temperature contributing to the maintenance of the glass streams in molten condition for a time sufficient to effect attenuation thereof, wherein the spinner diameter, the centrifugal acceleration at the spinner peripheral wall, the peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ spinner diameter 550 mm to 1500 mm centrifugal acceleration 4000 m/sec.sup.2 to 20000 m/sec.sup.2 peripheral velocity 50 m/s to 130 m/s burner pressure 100 mm to 900 mmm (water column) ______________________________________ thereby producing fibrous insulation blanket having the following characteristics: ______________________________________ fineness 2(5 g) to 5(5 g) micronaire conductivity 30 × 10.sup.-3 to 55 × 10.sup.-3 (W/m °K.) density 8 to 75 (Kg/m.sup.3). ______________________________________