Process and apparatus for the manufacture of fibers

Apparatus adapted for use in drawing of filaments from attenuable material in attenuable condition, such as molten glass, comprising a bushing having a chamber for the attenuable material in attenuable condition and having a bottom wall with downwardly presented wall portions at higher and lower levels, characterized in that the lower wall portions comprise bottom walls of bosses enclosing alveoles which are upwardly open to communicate with said chamber, the bosses being arranged in parallel series and each series comprising a multiplicity of spaced bosses, the higher wall portions of the bottom wall comprising a plurality of strip-like wall portions lying between series of bosses and extended between opposite edges of the bushing, means at said edges providing for attachment of electrical connections for effecting electrical resistance heating of the bushing by passage of current through said strip-like wall portions, the lower walls of the bosses each having a plurality of orifices for delivery of the attenuable material, and mechanism spaced below the bushing for drawing filaments from the attenuable material delivered through the alveoles from said chamber, and downwardly open channels below said strips extended between the series of bosses and having side wall portions on the sides of said bosses forming said downwardly open channels, said side wall portions being of sufficient depth to inhibit flooding of the attenuable material from the substantially continuous bottom wall of one boss to that of other bosses in adjoining series.

Apparatus adapted for use in the alternative drawing of attenuable material in attenuable condition, such as molten glass, into filaments of different sizes by change of fiberizing parameters, comprising a bushing and mechanism spaced below the bushing for drawing filaments from the material, said bushing having a chamber for attenuable material in attenuable condition and having a bottom wall with downwardly presented wall portions at higher and lower levels, the lower wall portions comprising bottom walls of bosses containing upwardly open alveoles in communication with said chamber, the bosses being arranged in a plurality of parallel series and the lower walls of the bosses having orifices for delivery of said material, the orifices in the bottom of each boss comprising a clustered group of at least three orifices, the downwardly presented surface of each boss being substantially continuous throughout the region immediatedly surrounding the orifices and the spacing between the orifices being sufficiently close to maintain a condition of flooding of said material on the substantially continuous surface between the orifices in communication with one alveole under specific drawing temperature conditions, and the downwardly open channels being of sufficient depth to inhibit flooding of said material from the substantially continuous surface surrounding the orifices in one boss to that of other bosses, and thereby provide for drawing of a single filament from the flooded material from an alveole, but the orifices being sufficiently spaced to maintain a non-flooded condition under other specific drawing temperature conditions and thereby provide for drawing of individual filaments from each orifice of said alveole.

Apparatus for forming strands from attenuable material in attenuable condition, such as molten glass, comprising a bushing having a chamber for the attenuable material in attenuable condition and having a bottom wall with downwardly presented wall portions at higher and lower levels, the lower wall portions comprising bottom walls of bosses containing alveoles upwardly open to communicate with said chamber, the bosses being arranged in a plurality of parallel series which extend in two relatively angled directions and intersect each other and having two series of parallel downwardly open intersecting channels between the intersecting series of bosses, and the lower walls of the bosses having orifices for delivery of said material, mechanism spaced below the bushing for drawing filaments from said material, and means for cooling the material delivered through the orifices by effecting radiant heat absorption and comprising thermally conductive solid state cooling fins mounted lengthwise of a parallel series of said channels, means for cooling the fins by thermal conduction through the material of the fins lengthwise thereof to at least one end of each fin, said cooling means further including thermally conductive manifold means for a cooling medium, one end of each fin being connected to the manifold means to provide for thermal conduction of heat from the fins to the manifold means, the channels with which the cooling fins are associated being open ended to provide for intake of air and the channels and the cooling fins being proportioned and relatively positioned to provide free flow of air from said channels laterally to the regions immediately below the bosses, and the downwardly presented surface of each boss being substantially continuous throughout the region immediately surrounding the orifices, the orifices in the bottom of each boss comprising at least three orifices, each orifice in communication with an alveole being substantially equidistantly spaced from adjacent orifices of the same alveole and being sufficiently close to maintain a condition of flooding of said material on the substantially continuous surface between the orifices and thereby provide for drawing a single filament from each alveole, and the downwardly open channels between the series of bosses being of sufficient depth and width to inhibit flooding of the attenuable material from the region surrounding the orifices of one boss to another.