The invention relates to a tip plate for a bushing for receiving a high temperature melt, which tip plate comprises several sections of different type, while the invention further includes a corresponding bushing to produce glass fibres.

A nozzle tip for producing glass fibers has a pair of long-side walls and a pair of short-side walls, each of the long-side walls and the short-side walls containing platinum or a platinum alloy, and a nozzle orifice for discharging the glass melt, the nozzle orifice being formed by the long-side walls and the short-side walls. The nozzle orifice has a flat hole shape in horizontal cross-section. Each of the long-side walls has a cut-out on a discharge side of the glass melt, a width of the cut-out being 10-55% of a length of a longitudinal center axis of the flat hole shape of the nozzle orifice. The pair of long-side walls has a symmetrical shape about the center axis of the nozzle orifice. This nozzle tip makes it possible to efficiently produce glass fibers having a desired cross-sectional shape.

A nozzle tip for producing glass fibers has a pair of long-side walls and a pair of short-side walls, each of the long-side walls and the short-side walls containing platinum or a platinum alloy, and a nozzle orifice for discharging the glass melt, the nozzle orifice being formed by the long-side walls and the short-side walls. The nozzle orifice has a flat hole shape in horizontal cross-section. Each of the long-side walls has a cut-out on a discharge side of the glass melt, a width of the cut-out being 10-55% of a length of a longitudinal center axis of the flat hole shape of the nozzle orifice. The pair of long-side walls has a symmetrical shape about the center axis of the nozzle orifice. This nozzle tip makes it possible to efficiently produce glass fibers having a desired cross-sectional shape.

Methods and apparatus for producing fibers from igneous rock, including basalt include heating igneous rock by electrical conductive coils to achieve an homogenous melt and forming homogenous fibers from the melt.

The present invention is a bushing for manufacturing a glass fiber that includes a base plate, a plurality of nozzles for discharging molten glass, and a nozzle group in which the plurality of nozzles are arranged in lines, being bonded to the base plate, wherein nozzles constituting at least one nozzle array among nozzle arrays of outermost layers of the nozzle group are plugged to a half or more of a nozzle length from a tip in depth. The glass-fiber-production bushing plate makes long-term, stable discharge of a uniform glass flow possible.

The present invention is a bushing for manufacturing a glass fiber that includes a base plate, a plurality of nozzles for discharging molten glass, and a nozzle group in which the plurality of nozzles are arranged in lines, being bonded to the base plate, wherein nozzles constituting at least one nozzle array among nozzle arrays of outermost layers of the nozzle group are plugged to a half or more of a nozzle length from a tip in depth. The glass-fiber-production bushing plate makes long-term, stable discharge of a uniform glass flow possible.

An optical fiber draw furnace muffle includes a body portion defining a substantially cylindrical cavity extending along a centerline axis of the muffle. A tapered portion has an interior surface which defines a first curved portion with a first radius of curvature and a second curved portion with a second radius of curvature. At least one of the first and second radii of curvature has a radius greater than a radius of the cylindrical cavity.

An optical fiber draw furnace muffle includes a body portion defining a substantially cylindrical cavity extending along a centerline axis of the muffle. A tapered portion has an interior surface which defines a first curved portion with a first radius of curvature and a second curved portion with a second radius of curvature. At least one of the first and second radii of curvature has a radius greater than a radius of the cylindrical cavity.

The bushing for producing glass fibers of the present disclosure includes a base plate; and nozzles arranged on the base plate and each configured to discharge glass melts. The base plate is provided with base orifices each having a horizontally flat cross section. Each of the nozzles is provided with a nozzle wall projecting from the base plate along an outline of a corresponding base orifice, and a nozzle orifice that penetrates the nozzle from the base orifice to a distal end of the nozzle wall while keeping the shape of the base orifice. The nozzle wall is provided with a pair of cutouts that do not project from the base plate. The cutouts oppose each other with a longitudinal center axis of the nozzle orifice in between. The width of each of the cutouts is 10% or more and 95% or less of the length of the longitudinal center axis of the nozzle orifice.

The bushing for producing glass fibers of the present disclosure includes a base plate; and nozzles arranged on the base plate and each configured to discharge glass melts. The base plate is provided with base orifices each having a horizontally flat cross section. Each of the nozzles is provided with a nozzle wall projecting from the base plate along an outline of a corresponding base orifice, and a nozzle orifice that penetrates the nozzle from the base orifice to a distal end of the nozzle wall while keeping the shape of the base orifice. The nozzle wall is provided with a pair of cutouts that do not project from the base plate. The cutouts oppose each other with a longitudinal center axis of the nozzle orifice in between. The width of each of the cutouts is 10% or more and 95% or less of the length of the longitudinal center axis of the nozzle orifice.