Method and apparatus for glass fiberization

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 peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ centrifugal acceleration 4000 to 20000 m/sec.sup.2 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 peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ centrifugal acceleration 4000 to 20000 m/sec.sup.2 peripheral velocity 50 m/s to 130 m/s burner pressure 100 mm to 900 mm (water column). ______________________________________

Claim 5

A method for producing a glass fiber blanket on a perforated conveyor with underlying suction means, the conveyor being located at the bottom of a fiber-receiving chamber having side walls at opposite edges of the conveyor, the method comprising delivering molten glass in attenuable condition to the inside surface of the perforated peripheral wall of a spinner mounted for rotation on a generally vertical axis and located in spaced relation above the conveyor and thereby centrifugally projecting streams of molten glass through the perforations, attenuating said streams to form fibers of substantially smaller diameter than said streams by subjecting the centrifugally projected streams to the action of a gaseous blast generated by an internal combustion burner, 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 depositing the attenuated fibers on the conveyor by directing said gaseous blast in an annular path surrounding the peripheral wall of the spinner and extended from the spinner toward the conveyor and thereby carrying the attenuated fibers toward the conveyor, the annular path of the blast being exposed to ambient air in an upper region of the receiving chamber with resultant induction of ambient air, the blast flow spreading with consequent decrease of the attenuated fiber content in edge portions of the blast as it approaches the conveyor, and selecting a spinner of a diameter such that the spreading of the fiber-laden blast flow is sufficient to cause the fiber-laden glass flow to impinge upon the side walls of the receiving chamber appreciably above the conveyor and thereby deflect edge portions of the blast flow and fibers carried thereby, with resultant increase in fiber deposit along the edge portions of the conveyor, thereby tending to equalize fiber deposit across the width of the conveyor.

Claim 6

A method for producing a glass fiber blanket on a perforated conveyor with underlying suction means, the conveyor being located at the bottom of a fiber-receiving chamber having side walls at opposite edges of the conveyor, the method comprising delivering molten glass in attenuable condition to the inside surface of the perforated peripheral wall of a spinner mounted for rotation on a generally vertical axis and located in spaced relation above the conveyor and thereby centrifugally projecting streams of molten glass through the perforations, attenuating said streams to form fibers of substantially smaller diameter than said streams by subjecting the centrifugally projected streams to the action of a gaseous blast generated by an internal combustion burner, 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 depositing the attenuated fibers on the conveyor by directing said gaseous blast in an annular path surrounding the peripheral wall of the spinner and extended from the spinner toward the conveyor and thereby carrying the attenuated fibers toward the conveyor, the annular path of the blast being exposed to ambient air in an upper region of the receiving chamber with resultant induction of ambient air, the blast flow spreading with consequent decrease of the attenuated fiber content in edge portions of the blast as it approaches the conveyor, and selecting a spinner of a diameter such that the spreading of the fiber-laden blast flow is sufficient to cause the fiber-laden glass flow to impinge upon the side walls of the receiving chamber appreciably above the conveyor and thereby deflect edge portions of the blast flow and fibers carried thereby, with resultant increase in fiber deposit along the edge portions of the conveyor, thereby tending to equalize fiber deposit across the width of the conveyor.

Claim 9

A method for centrifugally producing glass fiber insulation 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 centrifugal acceleration at the spinner peripheral wall, the peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ 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 mm (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 10

A method for centrifugally producing glass fiber insulation 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 centrifugal acceleration at the spinner peripheral wall, the peripheral velocity of the spinner and the burner pressure fall within the following ranges: ______________________________________ 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 mm (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). ______________________________________