Abstract:
A bushing system includes a bushing having a bottom plate with a plurality of holes from which filaments are drawn. At least one elongated support extends through the bushing generally along a longitudinal axis to hold and stabilize the bushing. To handle the harsh conditions under which the bushing is subjected, the support comprises an alumina-based ceramic that generally resists sagging or excessive expansion and contraction during heating and cooling.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Fiberglass is a thin glass fiber, which can be strong, light-weight, and a good insulator. These properties make fiberglass useful for a variety of applications. For example, fiberglass may be used as an insulator (e.g., an electrical insulator, a thermal insulator, or a sound insulator). Fiberglass may also be used in rigid objects, such as automobile panels, metal poles, or sports equipment (e.g., such that the rigid object consists primarily of fiberglass or such that fiberglass reinforces other materials). 
         [0002]    Fiberglass can be made by introducing molten glass into a bushing. The bushing includes side walls and a bottom plate to contain the molten glass. The bottom plate (comprising or attached to a tip plate) includes a number of small holes. Thus, a stream of the molten glass flows from each of these holes and underlying tips. These streams may be converted into fibers. 
         [0003]    Bushings are subject to harsh conditions. For example, the force caused by the molten material above the bottom plate may cause the bottom plate to sag over time, especially as manufacturers use increasingly larger bushings in order to produce fiberglass at a faster rate. Additionally, bushings are subject to extremely high temperatures, as the glass introduced into the bushings must stay in a molten state. Not only must the bushing withstand the high temperatures, but it must also withstand the heat expansions and subsequent contractions that accompany these temperatures. Thus, it is desirable to use a bushing system that can withstand the harsh conditions of fiber manufacturing. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    In one embodiment, the invention provides a bushing system that comprises a bushing having a bottom plate with a plurality of holes from which filaments are drawn. At least one elongated support extends through the bushing generally along a longitudinal axis to hold and stabilize the bushing. To handle the harsh conditions under which the bushing is subjected, the support comprises an alumina-based ceramic that generally resists sagging or excessive expansion and contraction during heating and cooling. In turn, deformation of the bottom plate is significantly reduced, thereby helping to prevent the geometry of the holes from changing. This in turn helps to prevent the breakage of the filaments when drawn through the holes. 
         [0005]    In one aspect, a plurality of elongated supports are employed and are spaced apart from each other and aligned with the longitudinal axis. Each of the supports may comprise yttria doped alumina. Further, a frame may be used to receive the elongated supports. This frame may comprise a pair of horizontal rails upon which the support is configured to rest. 
         [0006]    In another aspect, the alumina-based ceramic comprises a yttria doped alumina. In one arrangement, the alumina-based ceramic comprises alumina in major part, yttria in minor part and magnesia oxide in minor amount. Further, the minor amount of yttria may be in the range from about 0.1 weight percent to about 5 weight percent. 
         [0007]    To produce the alumina-based ceramic, alumina in major part may be combined with yttria oxide in minor amount and magnesium carbonate in minor amount to form an admixture. The admixture may be extruded and sintered at a temperature in the range from about 1550 degrees C. to about 1700 degrees C. Another technique for forming can include isostatic pressing. In some cases, the minor amount of yttria is in the range from about 0.1 weight percent to about 5 weight percent. The minor amount of magnesium carbonate (MgCO3) may be in the range from about 0.01 weight percent to about 1.5 weight percent, and in some cases from about 0.01 weight percent to about 0.2 weight percent. Further, the admixture may be milled and then spray dried prior to extrusion or pressing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIGS. 1A-1B  show an example of a bushing system  100 . 
           [0009]      FIG. 2  shows a cut-away depiction of part of a bushing system, illustrating examples of support-receiving elements. 
           [0010]      FIG. 3  shows a process for manufacturing fibers. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    As described above, over time, the bottom plate of a bushing may sag due to the load above it. This can cause the holes in the bottom plate to deform, thereby affecting the stream of molten glass that is forced through the hole. In turn, this can interfere with the other glass fibers, essentially ruining the production run. Once deformed, the bushing may need to be re-worked which usually entails melting down the bushing and recasting it. This can be both time consuming and expensive. Moreover, some of the expensive metals used to make the bushing will be lost. 
         [0012]    To address this problem, the bottom plate may be supported by elongated supports running in a direction parallel to the plane of the bottom plate. The ends of the supports may rest on a frame surrounding the bushing, such that the supports are supported by the frame. One critical aspect of the invention is to construct these supports such that they only minimally expand/contract and/or sag when subject to extremely harsh production conditions. One exemplary way to accomplish this is by constructing the supports of a material comprising alumina-based ceramic, and in particular a yttria doped alumina. 
         [0013]    One particular advantage of using such materials is that the supports may be made smaller, thus requiring less metal on the bushing to hold the supports. Or, the bushing could be may larger while maintaining the size of the cross sectional dimension of the supports, thus increasing production volumes. These efforts may significantly reduce the cost of the bushing. Further, the bushing will have a longer life, further reducing production costs. 
         [0014]    Exemplary Bushing System 
         [0015]      FIGS. 1A and 1B  show an example of a bushing system  100 . Bushing system  100  may include a bushing  120 , which may comprise a material that is substantially erosion-resistant. Bushing  120  may comprise platinum, rhodium, or an alloy thereof. 
         [0016]    Bushing  120  may comprise a screen (not shown), a number of side walls  122  and a bottom plate  124 . The screen may prevent contaminants in a molten material from entering the bushing  120 . Bottom plate  124  extends along a longitudinal direction  126   a  and a horizontal direction  126   b,  as shown in  FIG. 1B . Bottom plate  124  includes a plurality of small orifices or holes  128  (as shown in  FIG. 2 ). In some cases, bottom plate  124  may be similar to the plates described in U.S. Patent Application No. 2010/0064734, incorporated herein by reference. As one example, bottom plate 124 may include at least, equal to, and/or up to about 25, 50, 100, 250, 500, 1,000, 2,500, 5,000 or 10,000 holes. 
         [0017]    The diameters of the holes may be at least, equal to, and/or up to about 0.1, 0.25, 0.5, 1, 2.5, 5, 10, 25, 50, 100, 250, 500 or 1,000 m. The holes may be located in rows or staggered double rows. A tip or hollow nozzle may be located beneath each hole and may be connected to, welded to or integral with the hole. As mentioned above, it is critical that these holes not be deformed as this could case the glass stream to break and ruin a production run. 
         [0018]    Bushing  120  may comprise a screen (not shown), a number of side walls  122  and a bottom plate  124 . The screen may prevent contaminants in a molten material from entering the bushing  120 . Bottom plate  124  extends along a longitudinal direction  126   a  and a horizontal direction  126   b,  as shown in  FIG. 1B . Bottom plate  124  includes a plurality of small orifices or holes  128  (as shown in  FIG. 2 ). For example, bottom plate  124  may include at least, equal to, and/or up to about 25, 50, 100, 250, 500, 1,000, 2,500, 5,000 or 10,000 holes. The diameters of the holes may be at least, equal to, and/or up to about 0.1, 0.25, 0.5, 1, 2.5, 5, 10, 25, 50, 100, 250, 500 or 1,000 m. The holes may be located in rows or staggered double rows. A tip or hollow nozzle may be located beneath each hole and may be connected to, welded to or integral with the hole. 
         [0019]    Bushing  120  may include one or more support-receiving elements  130 . Side walls  122  may include an aperture  132 , which can receive a support  140 . In some instances, aperture  132  is only slightly larger than the support  140 . Side wall  122  may include an aperture perimeter that defines the shape of aperture  132 . In some instances, the aperture perimeter consists of a material different from the rest of side wall  122 . The aperture perimeter may be welded to side wall  122 . 
         [0020]    Support-receiving elements  130  may be constructed in a variety of ways. Three non-limiting examples are illustrated in  FIG. 2  and are referenced by reference numerals  130   a,    130   b  and  130   c  and are described in more detailed hereinafter. It will be appreciated that bushing  120  may include all of the same type of support-receiving elements (e.g., all made of support-receiving elements  130   a ), or could include combinations of different types of support-receiving elements. Further, the support-receiving elements  130  are coupled in part to bottom plate  124  using one or more connectors  134 . As also shown in  FIG. 2 , a variety of connectors may be used, either the same kind or different kinds. These are referenced using reference numerals  134   a ,  134   b,  and  134   c  and are described in more detail below. 
         [0021]    The support-receiving elements may comprise a sleeve, tubular element, hook or the like as described in more detail below. For example, support-receiving element  130  comprises a square or rectangular tube or sleeve that extends between the two side walls  122 . Between the side walls, each tubular element  130  is substantially hollow, such that, for example, a support  140  may extend completely through tubular element  130 . In some embodiments, the cross-section of tubular element  130  parallels the cross-section of the support  140 . Connecting support-receiving element  130  to bottom plate  124  are connectors  134 . If a force is applied to bottom plate  124  (e.g., by a molten material on top of the plate) that would promote sagging of the plate, the supports  140  assist to prevent such sagging. More specifically, the top of tubular support-receiving element  130  applies a downward force since it is connected to the bottom plate  124 . Support  140  counters this downward force and thus assists in preventing bottom plate  124  from sagging. As such, connecting bottom plate  124  to the support-receiving element may thus reduce or eliminate sagging. 
         [0022]    Support-receiving element  130  of  FIG. 1A  is similar to support-receiving element  130   a  of  FIG. 2 . However, it will be appreciated that instead of using a continuous tube as the support-receiving element, other configurations may be used as illustrated in  FIG. 2 . For example, a single surface may be used to form support-receiving element  130   b  that sits atop support  140 . Bushing  100  may include one or more connectors  134   b,  which may connect bottom plate  124  with support-receiving element  130   b.    
         [0023]    As another example, bushing  100  may include a support-receiving element  130   c  in the form of a hook  134   c  that also serves to couple the support-receiving element  130   c  to bottom plate  124 . In this way, the support-receiving element and the connector comprise the same component. However, as shown in  FIG. 1A  a connector  134  similar to connector  134   c  may also be used in combination with a support-receiving element  130  that is similar to support-receiving element  130   a.  In  FIG. 1A , connector  134  in the form of a hook may extend from bottom plate  124  up and around tubular element  130 . Thus, if bottom plate  124  were to begin to sag, and support  140  pressed against the top of tubular element  130 , the hook connection may inhibit bottom plate  124  from sagging. 
         [0024]    In some embodiments, support-receiving element  130 , the perimeter of aperture  132 , and/or connector  134  are made of substantially the same material as that of bottom plate  124  of bushing  120 . For example, this may allow support-receiving element  130   a  to expand in longitudinal direction  126   a  by an amount similar to the expansion of bottom plate  124 . In some instances, support-receiving element  130 , the perimeter of aperture  132  and/or connector  134  are made of a material that is different from the material of bottom plate  124 . For example, support-receiving element  130  and/or connector  134  may comprise a material that is more heat-resistant and/or exhibits less heat expansion than the material of bottom plate  124 . In some embodiments, support-receiving element  130 , the perimeter of aperture  132 , and/or connector  134  comprises a precious metal, such as platinum. 
         [0025]    Support  140  may traverse through apertures  132  and/or support-receiving elements  134  along the longitudinal direction  126   a.  The supports may comprise an elongate member. For example, the length of an elongated support  140  may be at least about 5, 10, 50, 100, 500, or 1000 times greater than a width or height of elongated support  140 . Support  140  may have a width or diameter, width, or height that is at least, equal to, or up to about 0.1 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 50 mm, 100 mm, or 500 mm. Support  140  may have a cross-section that is, for example, round or comprises a substantially straight line. In some instances, the cross-section is substantially a circle, a square, an oval or a rectangle. In some instances, the bottom of the cross-section is substantially flat. 
         [0026]    Support  140  may have a width, height, or diameter that is, for example, at least, equal to, or up to about 0.1 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, or 50 mm. Support  140  may have a length that is, for example, at least, equal to, or up to about 10 mm, 50 mm, 100 mm, 500 mm, or 1,000 mm. For example, in one instance, support  140  has a width of approximately 8 mm, a height of approximately 16 mm, and a length of 270 mm. Support  140  may be longer than the length bottom plate  124  in the longitudinal direction  126   a . This may, for example, allow the ends of the support  140  to be supported by a frame  160 . Support  140  may be, for example, at least, equal to, or up to about 0.1 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 50 mm, 100 mm, or 500 mm longer than the length of bottom plate  124  in the longitudinal direction  126   a.  Supports may be separated from each other by a length that is, for example, at least, equal to, or up to about 1 mm, 2.5 mm, 5 mm, 10 mm, or 25 mm, 50 mm. 
         [0027]    Support  140  may comprise a ceramic material. Support  140  may include alumina, silicon nitride, zirconia, nickel, iron, titanium, tungsten, molybdenum, niobrium or an alloy thereof. The material of support  140  may be such that support  140  has a lower thermal expansion coefficient and/or a greater hot creep strength than does bottom plate  124 . 
         [0028]    In one particular embodiment, support  140  may comprise a yttria-doped alumina. The yttria doping may allow support  140  to exhibit less creep deformation at high temperatures than an otherwise comparable non-doped support. Thus, using an yttria-doped alumina support may decrease sag of bottom plate  124 . Additionally, yttria doping may allow a smaller support  140  to be used to support bottom plate  124  and/or may reduce the amount of materials (e.g., precious metals) to be included in bushing system  100 . Alternatively or in addition, yttria doping may allow support  140  to support a larger bottom plate  124  and bushing (thereby increasing a throughput rate of the system), may increase the effective life of support  140 , and/or may increase the efficacy of support  140  in inhibiting sag of bottom plate  124 . One exemplary yttria-doped ceramic comprises a yttria doped alumina. In one arrangement, the alumina-based ceramic comprises alumina in major part, yttria in minor part and magnesia oxide in minor amount. In one particular embodiment, the minor amount of yttria may be in the range from about 0.1 weight percent to about 5 weight percent. 
         [0029]    Manufacture of supports  140  may begin, for example, by providing alumina particles or a mixture of powders which react to form alumina. Combined with the alumina is yttria oxide and magnesium carbonate to form an admixture. The amount of yttria may be in the range from about 0.1 weight percent to about 5 weight percent. The amount of magnesium carbonate may be in the range from about 0.01 weight percent to about 1.5 weight percent. 
         [0030]    The admixture is placed into an aqueous solution, such as water, and the admixture is milled to reduce the particle size. Following milling, the admixture is spray dried. The processed admixture may be extruded or pressed to shape the supports in the desired shape. The green body is then sintered at a temperature in the range from about 1550 degrees C. to about 1700 degrees C. During sintering, magnesia oxide is produced from the magnesia carbonate. The end product is cooled and may optionally be ground to smooth and/or straighten the support. 
         [0031]    In some embodiments, support  140  may be substantially solid. In some embodiments, support  140  is substantially hollow. In some embodiments, support  140  comprises a hollow and a solid part. 
         [0032]    As shown in  FIGS. 1A and 1B , frame  160  may support bushing  120 . In one embodiment, frame  160  supports an exterior portion of the bushing. For example, the frame may support an outer portion of the bushing surrounding the portion of the bushing comprising holes  128 . In some instances, bushing  120  may comprise one or more flanges  138 . Flanges  138  may extend over a portion of frame  160 . In some instances, flanges  138  extend along longitudinal direction  126   a.    
         [0033]    Frame  160  may support elongated supports  140 . For example, as shown in  FIGS. 1A and 1B , supports  140  may extend beyond bushing  120  in the longitudinal direction. Part or all of the portion of the supports extending beyond bushing  120  may be supported by frame  160 . In some instances, frame  160  supports bushing  120  by supporting supports  140 . In some instances, frame  160  directly supports bushing  120 . 
         [0034]    Frame  160  may include one, two or more horizontal rails  162 , which extend along horizontal direction  126   b.  Horizontal rails  162  may provide an upward force on supports  140 . In some embodiments, one or more lateral portions of supports  140  rest on horizontal rails  162 . The lateral portions may, for example, include an end portion of support  140  and/or a portion of the support that is not directly above bottom plate  124 . In some embodiments, support  140  does not directly rest on horizontal rails  162 , but one or more lateral portions of supports  140  are positioned over horizontal rails  162  and are indirectly supported by the rails. For example, one or more movement-promoting elements may separate the rails from the lateral portions, as discussed in more detail below. 
         [0035]    Frame  160  may comprise a metal. For example, frame  160  may comprise iron or steel. Frame  160  may comprise a material or may itself have a lower thermal expansion coefficient and/or a greater hot creep strength than does bottom plate  124  or than does support  140 . In some instances, different parts of frame  160  are made from different materials. 
         [0036]    Bushing  160  may be heated in order to ensure that material contained within the bushing is kept within a desired temperature. For example, bushing  160  may be heated to over 2000° F. to ensure that molten glass within the bushing stays in the molten state. These high temperatures may cause parts of bushing  160  and supports  140  to expand. If supports  140  are not free to move with respect to frame  160 , damage may be caused to one or more of support  140 , bushing  120  (e.g., at aperture perimeters on side wall  122  or support-receiving element  130 ), and frame  160 . For example, at high temperatures, the welding connecting aperture perimeters to side wall  122  may fail and support-receiving element  130  may tear, which may result in molten material (e.g., molten glass) leaking from bushing  120 . Thus, in some embodiments, bushing systems are provided that reduce friction, permit relative movement, and/or promote relative movement between supports  140  and frame  160  (e.g., horizontal rails  162 ) at high temperatures (e.g., 2200°-2400° F.). 
         [0037]    Bushing system  100  further includes a cooling water inlet  180  that leads to a cooling loop that lays on top of the bushing flange to seal to the bushing block to keep molten glass from escaping. Adjacent cooling water inlet  180  is a cooling water outlet  181 . Also, cooling water tubes  183  permit cooling water to be used to cool the bushing. Tubes  183  extend traverse across the bushing to permit cool water to be input from one side and the water to be removed from the other side. Tubes  186  provide air that is used during hanging to induce outside downward air flow along the array of bushing tips to further provide cooling during fiberization of the primary glass strands. 
         [0038]    Support-Receiving Elements 
         [0039]    As described above, a bushing may include one or more support-receiving elements.  FIG. 2  shows a cut-away depiction of a part of other bushing-system embodiments, which, for example, illustrate several other examples of support-receiving elements  230   a - 230   c.  In each of the three depicted example, side walls  222  include an aperture  232 , which can receive a support. In some instances, the aperture (e.g., aperture  232   a ) is only slightly larger than the support  240 . In some instances, the aperture (e.g., aperture  232   c ) extends to the top or to the bottom of the wall. While  FIG. 2  shows two apertures corresponding to each support, a side wall  222  may include larger apertures  232  that can receive multiple supports. 
         [0040]    As described in connection with  FIG. 1A , support-receiving element  230  may be comprise a sleeve or a tubular element.  FIG. 2  shows an example where a tubular support-receiving element  230   a  is used in a bushing. In this instance, tubular element  230   a  includes a substantially solid, continuous surface extending between two side walls  222 . Additionally each tubular element  230   a  may be substantially hollow, such that, for example, a support  240  may extend completely through tubular element  230   a.  In this instance, the cross-section of tubular element  230   a  parallels the cross-section of the support  240 . As described in further detail below, tubular element  230   a  is connected to bottom plate  224  (which comprises holes  228 ). Thus, if a force is applied to bottom plate  224  (e.g., by a molten material on top of the plate) that would promote sagging of the plate, the supports  240  (being supported by horizontal rails  262 ) may press on the top of tubular support-receiving element  230   a.  Connecting bottom plate  224  to the support-receiving element may thus reduce or eliminate sagging. 
         [0041]    Support-receiving element  230   b  comprises a top surface. Support  240  can then be positioned beneath the top surface. Support  240  may apply an upwards force on the top surface of support-receiving element  230   b  when a downwards force is applied to bottom plate  224  of a bushing. Thus, connecting bottom plate  224  to support-receiving element  230   b  may reduce or eliminate sagging that may otherwise occur. 
         [0042]    Support-receiving element  230   c  comprises an element extending from bottom plate  224  over support  240 . In some instances, element  230   c  comprises a hook-shape; in some instances, element  230   c  comprises a U-shape. Support  240  may apply an upwards force on the top portion of support-receiving element  230   c  when a downwards force is applied to bottom plate  224  of a bushing. Thus, connecting bottom plate  224  to support-receiving element  230   c  may reduce or eliminate sagging that may otherwise occur. 
         [0043]    As describe above, the bushing may include one or more connectors  234 , which may connect bottom plate  224  with support-receiving element  230 . Connectors  234  may include for example, a rod (e.g.,  234   a ), a plate, a bar (e.g.,  234   b ), a U-shaped component (e.g.,  234   c ) or a hook. Connector  234  may be independent of support-receiving element  230  (e.g., connectors  234   a  and  234   b  are distinct from support-receiving elements  230   a  and  230   b ) or connector  234  may comprise support-receiving element  230  (e.g., connector  234   c  comprises support-receiving element  230   c ). 
         [0044]    In some embodiments, bottom plate  224  is rigidly connected to support  240 . For example, hooks of connector  234   c  may be firmly attached to support  240 , or a shape or material of the hook may discourage movement of support  240  relative to component  234   c.  In some embodiments, connectors  234  and/or support-receiving element  230   c  are configured to allow support  240  to move relative to bottom plate  224 . For example, support  240  may be able to slide and/or expand longitudinally (and independently of bottom plate  224 ) within support-receiving element  230   a.  As another example, hooks of connector  234   c  may permit movement of support  240  relative to component  234   c.    
         [0045]      FIG. 2  shows a plurality of connectors  234  connecting bottom plate  224  to a single support  240 . In some instances, support  240  is connected to bottom plate  224  by a single connector. For example, connectors  234  may include a vertically oriented plate that extends across a substantial portion or across the entire bottom plate  224  in the longitudinal direction  226   a.  As another example, a single component (e.g., a post) may be positioned substantially in the center of bottom plate  224  along the longitudinal direction  226   a.    
         [0046]      FIG. 2  shows a variety of support-receiving elements  230  and a variety of connectors  234 . A bushing system may include a plurality of support-receiving elements  230  (e.g., to receive multiple supports  240 ) and a plurality of connectors  234 . In some instances, the connectors are all of the same type and/or the support-receiving elements are all of the same type. In other instances, a system may include multiple types of connectors and/or multiple types of support-receiving elements (e.g., as shown in  FIG. 2 ). While  FIG. 2  shows pairs between specific types of connectors  234  and support-receiving elements  230 , the pairs may be rearranged and/or other types of connectors  234  and support-receiving elements  230  not specifically described herein may be used. 
         [0047]    Fiber Manufacturing Process 
         [0048]      FIG. 6  shows a process  600  for manufacturing fibers. At  605 , a bushing system is provided. The bushing system may include any parts and may have any properties described herein. For example, the bushing system may include a bushing, supports to support a bottom plate of the bushing, a frame to support the supports, a friction-reducing means to reduce the effective friction between the supports and the frame, and a space—void of refractory insulating castable—surrounding a portion of the supports outside the bushing. 
         [0049]    At  610 , a molten material is received into a bushing of a bushing system. In some instances, a forehearth receives the molten material (e.g., a molten glass) from a refining zone of a melting furnace. While the material is in the forehearth, the temperature of the molten material may decrease and/or the molten material may be mixed. A plurality of refractory lined legs may extend from the forehearth to one or more bushings. The molten material may pass through a screen of the bushing, which may prevent contaminants in the molten material (e.g., fragments from the refractory lined legs) from entering the bushing. 
         [0050]    At  615 , heat is applied to the bushing. In some instances, bushing is electrically heated, e.g., by applying current to electrical terminals connected to the bushing. The bushing may be heated to a temperature that is within a center or upper portion of a fiberizing range for the material. If the temperature is too high, the material flowing out of holes of the bushing may form into discrete droplets and may not be able to be pulled into fibers. If the temperature is too low, the fiber may subsequently break due to excessive shear stresses during attenuation of the fiber. Thus, the bushing may be maintained at a temperature not associated with either of these disadvantages. The bushing may need to be maintained at a temperature higher than the ideal fiberizing temperature, as cooling may occur within tips under a bottom plate of the bushing. In some instances, the bushing is maintained at a temperature that is at least, equal to, or up to about 1,800° F., 2,000° F., 2,200° F., 2,400° F., 2,600° F., or 2,800° F. The temperature may be one which allows the molten material to exit tips underlying a bottom plate in the upper portion of the fiberizing range, such that the molten material exiting the tips forms into cones at the end of tip. 
         [0051]    At  620 , molten streams (produced through holes of the bushing) are received. In some instances, the molten material itself creates a sufficient head pressure to cause the material to exit through holes on a bottom plate, thereby forming molten streams. The streams may be received closely below each tip end under the bottom plate. In some instances, the molten streams comprise a molten cone formed under tips underlying the bottom plate. For example, they may be received within a fraction of an inch below the tip end. A high-speed winder may catch the streams and may subsequently attenuate them. 
         [0052]    At  625 , the streams are attenuated. During attenuation, the diameter of the streams may be decreased by a factor of, for example, at least, equal to, or up to about 2, 5, 10, 20, 50 or 100, to result in diameters of, for example, at least, equal to, or up to about 1, 5, 10, 13, 16, 19, 25, 50 or 100 microns. The winder may apply tension and pull the streams at hundreds to thousands of feet per minute to reduce the diameter. The molten material may be cooled during the attenuation. At  630 , the attenuated streams are solidified by continuing to cool the material.