Method of manufacturing high strength glass fibers in a direct melt operation and products formed there from

Method of manufacturing high-strength glass fibers in a direct melting process

And mixed products

Method Of Manufacturing High Strength Glass Fibers In A Direct Melt Operation And Products Formed There From

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Full description

Background of the invention

The present invention is directed generally to a method of manufacturing continuous glass fibers for use in high‑strength applications and products made therefrom, such as ballistic armor, pressure vessels, structural aerospace materials, and structural marine materials. materials, and structural materials for wind energy, such as windmill masts and blades.

Fiberglass reinforced composite materials have been available for use in marine and aerospace materials for some time. Other fibrous materials such as carbon fibers and aramid fibers are also available for use, although their cost is significantly higher. The materials of the present invention may employ any known manufacturing method, including compression molding, laminating, top spraying, hand laying, precast, compression molding, vacuum bag molding, bag molding. Pressure bag molding, press molding, transfer molding, vacuum assisted resin transfer molding, pultrusion molding, filament winding, casting, molding

Autoclave molding, resin transfer by centrifugal casting and continuous casting. The properties of the composite are controlled by the fibers and the resin, and the ynergy between the two produces material properties not available from the individual materials.

There are a number of resins useful in manufacturing composite materials including polyester resin, vinylester resin and epoxy resin. Polyester resin is suitable for a number of applications. Vinylester resin has lower viscosity before curing and more flexible postcure than polyester resin and is usually more resistant to degradation. Epoxy resin is usually transparent when it dries. Epoxy resin is a polyether resin formed by polymerization of bisphenol A, bisphenol F, bisphenol C, and compounds with a similar composition to epichlorohydrin, which causes the formation of reactive oxirane linkage. Epoxy resins may react with a variety of curing agents, including amines, anhydrides, mercaptans, and polyesters, to form an infusable solid. The reaction is a condensation reaction that usually does not create by-products. Cured epoxy resins have high strength, low shrinkage during curing. They are used as coatings, adhesives, castings, composites, or foam. Epoxy foam resins are also desirable for use in high strength applications as a structural molding material or as a structural colloid. Phenolics are thermoset resins formed by condensation of phenol, or phenol derivative, with an aldehyde, usually formaldehyde. Phenolics are mainly used in the manufacture of paints and plastics. Other high-strength standard resins include bismaleimide, poly-amide, vinyl ester phenolic, ethylene-acrylate or methacrylate copolymers, high-strength intermediate standard thermoplastics such as ionomer (i.e., methyl acrylate). Crosslinked ethylene-methyl acrylate or methyl methacrylate copolymer), polycarbonate, nylon cyclourethane, aramid, modified epoxy compounds modified epoxies.

The most common high-strength glass composition for making fiberglass is “S-glass”. “S-glass” is a family of glasses originally composed of oxides of magnesium, aluminum, and silicon in a chemical synthesis that produces glass fibers that have a higher mechanical strength than E-glass. The most commonly used member of the S-glass family S-Glass is known as S2-Glass. Glass-S2 contains approximately 65 wt% silicon dioxide SiO2, 25 wt% aluminum trioxide Al2O3, and approximately 10 wt% magnesium oxide MgO. S-Glass has a composition that was originally designed for use in high-strength applications such as ballistic armor.

R-Glass is usually a type of glass that is originally composed of oxides of silicon, aluminum, magnesium, and calcium with a chemical composition that produces glass fibers with higher mechanical strength than E-Glass. R-Glass has a composition containing 58- 60 wt% silicon dioxide SiO2, 23.5-25.5 wt% aluminum trioxide Al2O3, 14-17 wt% calcium oxide plus manganese oxide CaO plus MgO, 0 wt% boron trioxide B2O3, 0 wt% iron and less than 2 wt% miscellaneous components. R-glass contains more aluminum and silicon than E-glass and requires higher melting and processing temperatures during fiber forming. Typically, the melting and curing temperatures for R-glass are at least 160°C higher than for E-glass. This increase in curing temperature typically requires the use of a more expensive platinum-lined melter. In addition, the close proximity of the liquefaction temperature to the liquidus temperature in R-glass requires it to be transformed into fibers at a higher temperature than in E-glass.

Other well-known high-strength glass compositions can be found in US Patent Application Serial No. 11/267,739 entitled “Composition for High Performance Glass, High Performance Glass Fibers and Articles Therefrom,” published as US Patent Application No. 2008/0009403.

Both R-Glass and S-Glass are produced by melting the components of the formulations in a platinum‑lined melting container. The cost of forming R-glass and S-glass fibers is much greater than E-glass fibers due to the cost of producing the fibers with melters. Therefore, there is a need in the technical field for methods of forming useful glass compositions in the formation of high-performance glass fibers from a direct-melt process in a furnace that is essentially free of platinum or other noble metal materials and products composed thereof.

General description of the invention

The present invention includes a process for producing refined glass from a raw glass batch by a glass melter essentially free of platinum or other noble metal materials. The process involves shipping a raw glass batch to a glass melter, melting the raw glass batch within the melting zone and forming continuous fibers from the melt. The present invention also includes fibers formed by this method, and products made from those fibres.

In one embodiment of the invention includes a method of forming high-strength glass fibers in a continuous system having a furnace, a forehearth, and a metal bushing. The method includes providing a glass melting furnace to receive a batch of glass melting furnace, discharging the molten glass, and lining at least a portion of the furnace with essentially non-precious material to form a glass contact surface for the furnace. The glass batch is supplied to the furnace, the glass batch being capable of forming fiberizable molten glass fiberizable having a fibration ΔT greater than 45°F (25°C) and of producing glass fibers having a composition containing about 50 to about 75 wt percent dioxide. Silicon SiO2; About 15 and about 30 wt percent aluminum trioxide Al2O3; About 5 About 20 wt% magnesium oxide MgO; About zero about 10 wt% calcium oxide CaO; And about zero is about 5 wt% R2O, which equals R2O Total of lithium dioxide Li2O, sodium oxide Na2O and potassium oxide K2O. A glass batch is melted in a furnace by supplying heat from a furnace heat source, such as oxy-fuel burners, which form a pool of molten glass connected to a glass contact surface of the furnace. A forehearth is provided for transferring the molten glass from the furnace to the bushing, and at least part of the forehearth is lined with material substantially free of precious metals to form a forehearth glass contact surface. The molten glass is conveyed into the forehearth while heat is supplied from a heat source to the forehearth and flows through the forehearth along an essentially horizontal flow path formed by the glass contact surface of the forehearth. Molten glass is discharged from the forehearth into the metal liner at a temperature of about 2400°F (1316°C) to about 2900°F (1593°C) and at a predetermined viscosity (e.g., about 1000 Poise), and is formed into continuous fibers.

The invention includes a method of manufacturing a glass composition to form continuous glass fibers and products made therefrom that are suitable for use in high-strength applications. Compositions useful for the present invention of glass fibers may be inexpensively formed using low‑cost, direct melting in a furnace of essentially platinum or noble metal materials, including alloys thereof.

A useful composition of the present invention includes 64 75 wt% silicon dioxide SiO2, 16 26 wt% aluminum trioxide Al2O3, 8 12 wt% magnesium oxide MgO and 0 3.0 wt% R2O, where R2O represents the sum of lithium dioxide Li2O, sodium oxide Na2O and oxide. Potassium K2O.

Another useful composition of the present invention includes 64 75 wt% silicon dioxide SiO2, 16 24 wt% aluminum trioxide Al2O3, 8 12 wt% magnesium oxide MgO and 0.25 to 3.0 wt% R2O, where R2O represents total lithium dioxide Li2O, Sodium oxide Na2O and potassium oxide K2O. In certain embodiments, the glass composition is composed of 64 70 wt% silicon dioxide SiO2, 17 22 wt% aluminum trioxide Al2O3, 9 12 wt% magnesium oxide MgO and 1.75 - 3.0 wt% R2O, where R2O represents total lithium dioxide Li2O. Sodium oxide, Na2O, and potassium oxide, K2O. In another embodiment, the glass composition useful in the present invention is composed of 64 70 wt% silicon dioxide SiO2, 17 22 wt% aluminum trioxide Al2O3, 9 12 wt% magnesium oxide MgO and 1.75 - 3.0 wt% lithium dioxide Li2O.

Still another composition useful in the present invention includes 50 75 wt% silicon dioxide SiO2, 13 30 wt% aluminum trioxide Al2O3, 5 20 wt% magnesium oxide MgO, 0 10 wt% calcium oxide CaO, and 0 5 wt% R2O. Where R2O represents the sum of lithium dioxide Li2O, sodium oxide Na2O and potassium oxide K2O.

In certain representative embodiments, the composition contains no more than about 5.0 wt % of compounds such as CaO, P2O5, ZnO, ZrO2, SrO, BaO, SO3, F, B2O3, TiO2, Fe2O3, CeO2 and BeO2. In other representative embodiments the composition is free of intentionally added CeO2 and BeO2. Still in representative embodiments, the composition preferably contains no more than about 4 wt % of compounds or halogens such as ZnO, SO3, fluorine, B2O3, TiO2, ZrO2 and Fe2O3.

In some representative embodiments, the desired properties of the high-performance fibers manufactured by the present invention include a fiber formation temperature of less than 2650°F (1454°C) and a liquefaction temperature that is preferably 80°F (44°C) below the fiber formation temperature Celsius) at least, more preferably at least about 120°F (67°C), and preferably at least about 150°F (83°C).

In other exemplary embodiments, the desired properties of the high-performance fibers manufactured by the present invention include a fiberizing temperature of 2400-2900°F (1316-1593°C) and a liquidus temperature that is below the fiberizing temperature of 45°F (25°C).

The present invention also provides a structural part having improved structural properties at reduced costs and improved manufacturability. Direct melt formation of continuous fiberglass uses low‑cost melting in a glass melter essentially devoid of platinum or other precious metals. The relatively low fiber formation temperature of the glass fibers used in high‑strength applications of the present invention allows improved fiber processing at a reduced cost. The materials of the present invention are typically formed by compression molding, laminating, spray up, hand spray up, prepreg, compression molding, vacuum bag molding, pressure bag molding. Bag molding, press molding, transfer molding, vacuum assisted resin transfer molding, pultrusion molding, filament winding, casting, autoclaved molding Autoclave molding, resin transfer by centrifugal casting or continuous casting.

The fibers produced used in the present invention are substantially less expensive to make and also have good strength and density properties. The density of the fibers used in the present invention ranges from 2.434 to 2.520 g/cm³, and more preferably 2.434 to 2.486 g/cm³ and has a girth modulus greater than 12.7 MPa/square inch and an original fiber strength greater than 680 kPa/cm2.

Brief explanation of the drawings

Figure 1 represents a longitudinal view of a cross-sectional section of a glass melting furnace operative with the method of the present invention;

Figure 2 represents a cross-sectional plan view of the glass melting furnace of Figure 1 taken along line 22;

Figure 3 represents a cross-sectional view of a glass melting furnace. Figure 1 along line 33 shows two burners adjacent to the wall of the upper end of the furnace.

Figure 4 represents an alternate cross-sectional plan view of a glass melting furnace of an alternate cross-sectional plan view of Figure 1 taken along line 33, which shows one burner adjacent to the end wall of the furnace; And

Figure 5 represents a side view, in partial cross section, of a metal liner assembly/support structure arrangement for producing continuous glass filaments useful in the method of the present invention.

Figure 6 represents a horizontal view of the top in cross section of a forehearth useful in the method of the present invention for transporting molten glass from a glass melting furnace to a bushing support/assembly.

Figure 7 represents a cross-sectional vertical side view of another exemplary front burner useful in the method of the present invention.

Detailed description

The present invention will now be described by reference occasionally to particular embodiments of the invention. This invention may, however, be embodied in various forms and should not be construed as being limited to the embodiments contained herein. Instead, such embodiments are provided such that this description is comprehensive and complete, and will serve to communicate the full scope of the invention to those who are experts in the art.

Unless otherwise specified, all technical and scientific terms used herein have the same meaning as would normally be understood by a lay expert in the field to which this invention relates. Terms used in describing the invention herein are intended to describe specific embodiments only and are not intended to limit the invention. As used in the description of the invention and the appended claims, the singular forms of “indefinite article” and “knowledge” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Unless otherwise noted, it should be understood that all figures expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so on as used in descriptions and claims may in all cases be modified by the term “about.” Accordingly, unless otherwise stated, the numerical properties shown in the description and claims are approximate and may vary depending on the properties to be obtained in embodiments of the present invention.

Although the numerical ranges and variables defining the broad scope of the invention are approximate, the numerical values shown in the given examples are reported as accurately as possible. Any numerical values, however, inherently contain some errors necessarily resulting from the error in their measurements.

The fiberizing properties of the glass composition used to form the glass fibers of the present invention include fiberizing temperature, liquefaction temperature, and delta-T. Unless otherwise specified here, the fiberizing temperature is defined as the temperature corresponding to a viscosity of 1000 poise (log 3°C). An expert in the field will recognize that other fiberizing temperatures may be defined; for example, fiberizing temperatures may be defined as the temperature corresponding to a viscosity of 316 poise (register 2.5 degrees).

As discussed in more detail below, in some embodiments lower fiberizing temperatures reduce the cost of fiber production, allow longer bushing life, increase productivity, and allow the glass to be melted in a melter largely devoid of platinum or other noble metals. And reduce energy use. For example, at a lower sintering temperature, the liner operates at a cooler temperature and does not “sag” as quickly. Sagging is a phenomenon that occurs in bushings that are kept at high temperatures for long periods. By lowering the curing temperature, the sag rate of the bushing may be reduced and the life of the liner may be increased. In addition, a lower fiberizing temperature allows for higher productivity since more glass can be melted in a given period of time and with a given energy input. As a result, the production cost is reduced. In addition, a lower fiberizing temperature will also allow for innovative glass shaping and melting of the composition in a refractory-lined melter, or an externally cooled-walled melting device, where both the melting and fibrating temperatures are Below the upper usage temperatures of many commercially available refractories or other materials when providing external cooling.

The liquidus temperature is defined as the highest temperature at which equilibrium exists between the liquid glass and its primary crystalline phase. At all temperatures above the liquefaction temperature, the glass is free of crystals in its underlying layer. At temperatures lower than the liquefaction temperature, liquidus, crystals may form.

Another fiberizing property is delta-T (ΔT), which is defined as the difference between the fiberizing temperature and the liquidus temperature. A greater ΔT provides greater flexibility during the formation of glass fibers and helps inhibit the formation of crystals within the melt during the melting and fiberizing process. Increasing ΔT also reduces the cost of producing glass fibers by allowing a longer liner life and by providing a wider process framework for forming the fibers.

Conversely, a higher fiber temperature and/or smaller ΔT means that the fiber forming process is less forgiving, and more sensitive to temperature variations, cold spots and slow moving glass.

The glass compositions used in the present invention are advantageously suitable for melting in a furnace or glass melter substantially free of platinum or other noble metals and their alloys, including refractory-lined glass melting devices. Commercially available glass melters, commercially available glass melters lined with externally cooled walls, for example water-cooled walls.

The starting batch components typically include SiO2 (ground silica sand), Al2O3 (calcinated alumina), Li2CO3 (lithium carbonate), H3BO3 (boric acid), NaCaB5O98H2O (eulexite), 2CaO-3B2O3-5H2O (colemanite) as well as series modifiers of Source materials such as MgCO3 (magnesite), CaCO3 (limestone), SrCO3 (strontianite), BaCO3 (weatherite), ZrSiO4 (zircon), and Na2CO3 (nitrite). An expert in the field will recognize that other starting materials may be used. Additional unlimited examples of suitable starting batch components include choelite (Al2Si2O5(OH)4), pyrophyllite (Al2Si4O10(OH)2), bauxite (AlO(OH)), wollastonite (CaSiO3), spodumene (LiAlSi2O6), feldspar (CaAl2Si2O8). , dolomite (CaMg(CO2)2), lime (CaO), dolomitic quicklime (CaMgO2), and hydrated lime (Ca(OH)2).

Glass Melting Furnace

Figures 1-4 depict a glass melting furnace (10) useful in the method of forming glass fibers described here and shown in the examples and protective elements below. It may also be required to use oxygen-fired heating within the blast furnace, as set forth in US Patent No. 509, 7, 819 entitled OXYGEN-FIRED FRONT END FOR GLASS FORMING OPERATION, inventors David J Baker et al., and the entry Here it is entirely for reference. The glass melting furnace (10) delivers molten glass to the glass forehearth (12).

In one representative embodiment, the molten glass consists of 50-75 wt% SiO2, 13-30 wt% Al2O3, 5-20 wt% MgO, 0-10 wt% CaO, 0 to 5 wt% R2O, where R2O represents total Li2O. , Na2O and K2O. This representative embodiment includes glass compositions that have a higher fiberizing temperature, eg 2400-2900°F (1316-1593°C), and/or a liquefaction temperature that is lower than the fiberizing temperature by as little as 45°F (25°C).

In another representative embodiment, the molten glass consists of about 64-75 wt% SiO2, 16-26 wt% Al2O3, 8-12 wt% MgO and 0 to 3.0 wt% R2O, where R2O represents the sum of Li2O, Na2O and K2O.

Still in another representative embodiment, the molten glass consists of about 64-75 wt% SiO2, 16-24 wt% Al2O3, 8-12 wt% MgO and 0.25 to 3.0 wt% R2O, where R2O is the sum of Li2O, Na2O and K2O. . A fiber formed according to the method of this representative embodiment will have a fiberizing temperature less than 2650°F (1454°C), in some embodiments less than about 2625°F (1458°C), in other embodiments less than about 2600°F (1427 degrees Celsius) and in some embodiments less than about 2575 degrees Fahrenheit (1413 degrees Celsius), and the liquefaction temperature is at least 80 degrees Fahrenheit (44 degrees Celsius) lower than the fiberizing temperature in some embodiments. Other embodiments are at least about 120 degrees Fahrenheit (67 degrees Celsius), and still other embodiments are at least about 150 degrees Fahrenheit (83 degrees Celsius).

Still in another representative embodiment, the molten glass consists of 50-75 wt% SiO2, 13-30 wt% Al2O3, 5-20 wt% MgO, 0-10 wt% CaO, 0 to 5 wt% R2O, where R2O is the sum of Li2O, Na2O and K2O. This representative embodiment includes glass compositions that have a liquidus temperature higher than the 3rd register of the fiberizing temperature, i.e. a negative ΔT such as -122°F (-68°C). This composition may be fiberized at a higher temperature, for example 2.5 log fiberizing temperature corresponding to a viscosity of 316 Poise.

In some representative embodiments, the composition contains not more than about 5.0 weight % of oxides or compounds such as CaO, P2O5, ZnO, ZrO2, SrO, BaO, SO3, fluorine, B2O3, TiO2, Fe2O3, K2O, CeO2 and BeO2. In other representative embodiments the composition is devoid of intentionally added CeO2 and BeO2.

The fibers produced and used in the present invention have a substantially lower manufacturing cost and also have good strength and density properties. The density of the fibers used in the present invention ranges between 2.434 and 2.520 g/cm³, and more preferably 2.434-2.486 g/cm³. Also, the glass fibers of the present invention will have, in some embodiments, an original fiber strength exceeding 680 knots per square inch, in other embodiments a strength exceeding about 700 knots per square inch, and also in other embodiments a strength exceeding about 730 knots per square inch. Also, the fiberglass will usefully have a modulus greater than 12.0 knots per square inch, in some embodiments greater than about 12.18 knots per square inch, and in some embodiments greater than about 12.7 knots per square inch.

The method of the present invention is preferably made using a glass melting furnace (10), comprising an elongated channel containing an upstream end wall (14), a downstream end wall (16), and two side walls. walls (18), floor (20), and roof (22). All components of the glass melting furnace (10) are made of suitable refractory materials such as alumina, chromic oxide, silica, alumina-silica, zircon, zirconia-alumina-silica. Alumina-silica, or similar oxide-based refractory materials, especially surfaces in contact with molten glass. The roof (22) is generally shown to have a transverse arch shape along the longitudinal axis of the channel structure; However, the roof may have any suitable design. The roof (22) is usually placed about 3-10 feet above the surface of the glass pane (30). The roof (30) glass batch is a mixture of raw materials used in the manufacture of glass according to the present invention.

The glass melting furnace (10) may optionally include one or more bubblers (24) and/or electrical boost electrodes (not shown). Bubblers (24) and/or electrical boost electrodes increase the temperature of the bulk glass and increase molten glass circulation under the batch cover.

Bubblers (24) and/or electrical boost electrodes may be particularly useful in second and third embodiments, which include glass compositions having a higher fiberizing temperature, for example, 2400-2900 degrees Fahrenheit (1316 1593 °C) and/or a low ΔT, for example as low as 45 °F (25 °C), or even a negative ΔT such as -122 °F (-68 °C), where devitrification is more likely.

In addition, the glass melting furnace (10) may include two successive zones, an upstream melting zone (26) and a downstream refining zone (28). In the melting zone (26), the glass batch assembly (30) may be charged into the furnace using a charging device (32) of a type well known in the technical field.

In a suitable melter configuration, the glass batch material (30) forms a batch layer of solid particles on the surface of the molten glass in the molten glass in the melting zone (26) of the glass melting furnace. (10). The floating solid particles of the glass batch material (30) are at least partially melted by at least one burner (34) having a controlled flame shape and length mounted within the roof (22) of the glass melting furnace 10).

In one preferred embodiment, as shown in Figure 1, the glass melting furnace (10) includes three burners (34). One single burner (34) is placed in an upward direction from two burners (34) placed adjacent to it in a downward direction. However, it will be appreciated that any number of burners (34) may be placed at any suitable location in the roof (22) of the furnace (10) on the batch to work on the melting of the glass batch (30). For example, two (34) burners may be placed side by side (Figure 3) or a single burner may be used (Figure 4).

It should be noted that the burners (34) of the glass melting furnace (10) may be arranged in the crown (roof) of the furnace, in the side walls, end walls, immersed within the batch or molten glass, or in a combination thereof.

Other fuses may be used without departing from the present invention. Suitable melters include air-gas melters, oxygen-gas melters, electrically heated melters, or any fossil fuel fired melter. It is possible to add an electric booster or bubblers to any melting process. It may also include a separate refining zone (as shown in Figure 1) or a refining zone within the main melter tank.

Forehearth Arrangement

The forehearth receives the molten glass discharged from the glass melting furnace and transports the molten glass, discharging the molten glass in a suitable condition to the forming position. The forehearth components may be lined with suitable refractory materials such as alumina, chromic oxide, silica, alumina-silica, zircon, zirconia-alumina-silica, or other refractory materials. Similar oxide-based coatings, especially surfaces that come into contact with molten glass. Preferably, such forehearth glass contact surfaces shall be lined with chromium oxide, zirconia or a combination thereof.

For compositions that have a fiberizing temperature below 2650°F (1454°C) and a liquidus temperature that is at least 80°F (44°C) below the fiberizing temperature, a burner may be used. Traditional front.

For other installations where the fiberizing temperature is high and/or ΔT is low, other front burner arrangements may be useful in inducing an isothermal condition in the molten glass, by which devitrification is prevented. For example, conveying molten glass through the forehearth to a shallow depth (D), e.g., less than 20 cm (8 in), or preferably less than 9 cm (3.5 in), will improve conveying. Heat by radiation throughout the molten glass. Oxy-fuel burners are especially useful as a forehearth heat source in this regard. Oxy-fuel firing system is usually supplied by BH-F (Engineering) Ltd. of England. As defined herein, oxygen-fuel fired burners are burners that use high-purity oxygen (i.e., typically 90 to 99 percent purity with a combination of nitrogen and argon impurities) as the oxidizer, rather than air. The environment used in air-fuel burners and fossil fuels to provide a combustible hydrocarbon supply, but may include combustible hydrocarbon supplies that use oxygen-rich air oxygen-enriched air (for example, 30 to 90 percent purity). The flame temperature of an oxygen-gas burner is about 2315 to 2871 degrees Celsius (4200 to about 5200 degrees Fahrenheit). At this temperature, the flame and combustion products radiate energy at wavelengths that the molten glass can absorb. This helps maintain a uniform glass temperature horizontally across the surface of the molten glass and vertically through the molten glass.

Air-fuel burners may also be used as a forehearth heat source, especially when installed at a very close spacing, such as 4 inches.

A representative front burner arrangement useful in the present invention is shown in Figures 6 and 7. The Forehearth front burner (322a) is adapted to deliver molten substance (e.g., molten substance G) from the glass melting furnace to a point of production (e.g., forming position, discussed below). Molten glass (G) does not contact the upper part of the forehearth (322A). Accordingly, this part can be constructed from a relatively inexpensive forehearth refractory material (e.g., a refractory material with superior composition, such as silica, mullite, or other materials that are not required to withstand the corrosive effects of molten glass (G). ).

The lower part of the front burner (322A) is below the level of the glass (L) and thus creates a glass contact surface which comes into contact with the molten glass (G). Accordingly, this part of the front burner (322A) is constructed of a more expensive glass contact material. A ceramic refractory material (for example, zircon, chromic oxide, or other suitable material) is suitable as a refractory material in contact with glass because it can withstand the corrosive effects of molten glass (G).

The front burner (322a) may include a top or crown (not shown), a bottom (also not shown), and sidewalls (328a). The front burner (322A) has an upper end, generally referred to as (330A), and a downstream end, generally referred to as (332A). An open end (334) may be provided at the downstream end (332a) of the forehearth (322a). An end wall (336a) may be provided at the upstream end (330a) of the forehearth 322a). One or more glass orifices (338) may be provided at the bottom of forehearth (322a) proximal to, adjacent to, or near the end wall (336a). The forehearth of the front end, as previously shown, is that part of the forehearth (322a) which has an end wall (336a) and glass orifices (338) at the base.

Forehearth burners (344), such as oxygen-fuel burners, are positioned above the glass level (L), shown in Figure 7. Forehearth burners (344) are oriented in a plane (e.g., horizontal to Large extent) perpendicular to the surfaces (340) and at an acute angle to the surfaces (340). The forehearth burners (344) project toward the downstream end 332a of the forehearth burner (322a) at an angle between about 5 degrees and about 85 degrees to the surfaces (340), as shown in Figure 6. The Forehearth burners (344) may be staggered or alternatively spaced such that the opposing forehearth burners (344) in the opposite side walls (328a) are horizontally opposite or not horizontally aligned (they are not vertically aligned when viewed in Fig. 6) With each other.

The flame temperature of an oxygen-fuel burner is approximately 2316-2871 degrees Celsius (4200-5200 degrees Fahrenheit). However, the flame is preferably very small. Therefore, the flame does not contact the sidewalls directly (328a). However, the radiant heat from the flame is very large. Although the flame does not contact the sidewalls (328a) directly, the sidewalls (328a) are sufficiently heated by convection or otherwise radiant heat from the flame. This radiant heat is sufficient to properly condition the molten glass (G) and hold the molten glass G at a desired temperature without compromising the integrity of the forehearth (322A) by exposing the forehearth (322A) to excessively high temperatures. This applies even if the burners (344) are spaced about 30cm-152cm (1 ft to about 5 ft) apart.

It should be understood that other forehearth burner arrangements are possible and within the scope of the invention. For example, another representative burner arrangement is shown in Figure 7. The forehearth burners (344) are oriented in a plane (e.g., a substantially vertical plane) perpendicular to the surface (346) and at an acute angle to the surface (346). The forehearth burners (344) may protrude toward the upper end 330C of the channel (322C) at an angle between about 5 degrees and about 85 degrees with respect to the surface 346, as shown in Figure 7. Alternatively, the forehearth burners may be (344) protrudes toward the downstream end (332c) of the chann (322c) at an angle between about 95 degrees and about 175 degrees with respect to the surface (346).

It should be noted that burners may be arranged in the crown (roof) of the front burner, in side walls, end walls, immersed within the batch or molten glass, or in combinations thereof.

Bushing assembly

As shown in Figure 5, the liner assembly 100 includes a bushing liner (110) and a bushing frame 210. The liner (110) includes a main bushing body (120) with sidewalls (122) and a tip plate (124) extending between the walls. Sidewalls (122). The main body (120) is placed under the bushing block (300) which, in turn, is placed under the front burner (310). In practicing the method of the present invention, a stream of molten glass is received by the main body (120) of the front burner (310). The forehearth (310) receives molten glass from a melter (10) (shown in Figure 1). A delivery channel (40) is placed between the fusing device (10) and the forehearth (310) to deliver the molten glass batch composition (30) from the fusing device (10) to the forehearth (310). The front burner (310) and liner mold (300) may be conventional in construction and may be formed from refractory materials.

The top plate (124) includes a plurality of nozzles (124a) (also referred to as nozzles) through which various streams of molten glass nozzles may be discharged. Streams of melt may be mechanically drawn from the tip plate (124) to form continuous filaments (125) via a conventional winder device (400) such as a winder, fan, or other thinning device. The filaments (125) may be assembled into one or more connected strands of filaments (125a) after receiving a protective coating of a sizing composition from a sizing applicator (410). The attached filaments (125a) may be wound onto a rotating collet (402) with the winder device (400) to form a package (125b). Continuous filaments (125) may also be processed into other desirable glass composite materials including, but not limited to, wet use chopped strand fibers, dry use chopped strand fibers, matting of continuous filament mats, continuous filament mats, wet-formed mats continuous filament mats or air-regulated mats continuous filament mats.

The high-strength material of the present invention uses the previously described formed fibers as reinforcement for glass fibers within a polymer matrix material. Typical matrix materials include epoxies, phenolic resins, vinylesters, and polyesters. Materials may be formed by any suitable manufacturing technique including compression molding, laminating, spraying, hand laying, prefabricated lay-up (prepreg), vacuum bag molding molding, pressure bag molding, press molding, transfer molding, vacuum-assisted resin transfer molding, pultrusion molding, filament winding, casting, autoclave molding, centrifugal resin transfer casting and continuous casting.

After describing the invention in general, further understanding may be obtained by referring to some specific examples shown below which are provided for illustrative purposes only and are not intended to be comprehensive or limited unless otherwise specified.

Examples

The glass in the examples listed in Tables IIA and IIC was melted in platinum crucibles or in a continuous platinum-lined melter to determine the mechanical and physical properties of the glass and the glass and fibers produced from it. The units for measuring physical properties are: Viscosity (degrees Fahrenheit), liquefaction temperature (degrees Fahrenheit) and ΔT (degrees Fahrenheit). In some examples, the glass was fiberized and the strength (knots per square inch), density (g/cc), and Modulus (knots per square inch) were measured.

The fiberizing temperature was measured using a rotating spindle viscometer. The fiberizing viscosity is specified as 1000 poise. The liquefaction temperature was measured by placing a platinum container filled with glass in a convection oven for 16 hours. It was considered that the highest temperature at which crystals were found was the liquefaction temperature. The modulus was measured using the acoustic technique on one of the glass fibers. The tensile strength was measured on one of the original fibers of glass.

Table II-A

the glass

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

SiO2

67.2

Al2O3

MgO

9.8

Li2O

Measured viscosity x

1388.3

1516

1453

1402.7

1403

1349

The temperature of the liquidus state first measured x

1267.2

1437.2

1425

1277.8

1261.1

1257.8

The temperature of the liquidus state measured second o

1261.1

1237.8

1434.4

1285.6

1264.4

1270

DT s

121.1

125

141.9

91.6

Measured density (g/cm3)

2.459

2.452

2.481

2.450

2.441

2.482

Table II-B

the glass

Example 7

Example 8

Example 9

Example 10

Example 11

Example 12

SiO2

70

69

70

65

66

65

Al2O3

18

17

21

22

22

22

MgO

9

11

9

11

9

10

Li2O

3

3

zero

2

3

3

Measured viscosity x

1395.6

1368.9

1511.1

1385

1383.3

1363.3

The temperature of the liquidus state first measured x

1266.1

1223.3

1425

1353.3

1310.6

1293.9

The temperature of the liquidus state measured second o

1273

1283.9

1428.3

1350

1312.2

1305.6

DT s

129.5

135.6

86.1

31.7

72.7

69.4

Measured density (g/cc)

2.434

2.455

2.443

2.486

2.460

2.474

Table II-C

the glass

Example 13

Example 14

Example 15

Example 16

Example 17

Example 18

SiO2

70

67.32

67.57

68.27

68.02

67.76

Al2O3

19

20.49

20.49

20.10

20.10

20.10

MgO

11

10.00

10.00

9.69

9.69

9.69

Li2O

zero

2.00

1.75

1.75

2.00

2.25

Measured viscosity x

1479

1406.1

1417.8

1425.6

1414.4

1397.2

The temperature of the liquidus state first measured x

1424.4

1346.7

1363.3

1341.1

1332.8

1315

The temperature of the liquidus state measured second o

1416.7

1341.7

1353.9

1353.9

1336.1

1318.9

DT s

54.6

59.4

54.5

84.5

81.6

82.2

Measured density (g/cc)

2.453

2.461

2.452

The useful compositions of the present invention may also include chain modifiers such as Na2O, CaO and B2O3. These combinations are shown in Table II-D (below).

Table II-D

the glass

Example 19

Example 21

Example 22

Example 22

Example 23

Example 24

SiO2

75

66

65

65

66

74

Al2O3

15

20

20

24

19

15

MgO

8

9

8

8

9

8

Li2O

2

zero

zero

zero

Na2O

2

2

3

CaO

2

4

B2O3

2

4

Measured viscosity x

1518.3

1430.6

1353.9

1465

1542.8

The temperature of the liquidus state first measured x

1327.8

1498.3

1434.4

1443.3

1471.1

DT s

190.2

-67.7

30.6

71.7

The fibers produced by the present invention have superior modulus and strength properties. Example 1 fibers have a measured modulus of 12.71 knots per square inch and a measured strength of 688 knots per square inch. Example 3 fiber has a measured modulus of 12.96 knots per square inch and a measured strength of 737 knots per square inch. Example 17 fibers have a measured modulus of 12.75 knots per square inch and a measured strength of 734 knots per square inch.

As is understood in the art, representative formulations created do not always amount to 100% of the listed components due to statistical conventions (e.g., rounding and averaging) and the fact that some formulations may include impurities that are not listed. Of course, the actual amounts of all ingredients, including any impurities, in a formula are always 100%. Furthermore, it should be understood that when small amounts of ingredients are specified in formulations, for example, amounts on the order of about 0.05 weight percent or less, those ingredients may be present in the form of trace amounts of impurities present in the raw materials, rather than It was added intentionally.

In addition, components may be added to the batch composition, for example, to facilitate processing, which are subsequently removed, thus forming a glass composition that is essentially free of such components. Thus, for example, small amounts of components such as fluorine and sulfate may be present in the form of trace impurities in the raw materials providing the silica, lithia, alumina, and magnesia components in commercial practice of the invention or may be Processing aids that are essentially lost during the manufacturing process.

As shown by the preceding examples, some of the glass fiber compositions useful in the invention have useful properties, such as low fiberizing temperatures and large differences between liquefaction temperatures and fiberizing temperatures (high ΔT values). Other advantages and obvious modifications of the invention will be apparent to the craftsman from the foregoing description and also from practice of the invention.

In some embodiments, the high-performance fiberizing glass produced by the present invention is melted and refined at relatively low temperatures, and has a practical viscosity over a wide range of relatively low temperatures, and a low liquefaction temperature range.

In other embodiments, the high-performance glass produced by the present invention is melted and refined at relatively high temperatures, and has a workable viscosity over a relatively small temperature range.

The invention herein has been described previously both generally and with respect to specific embodiments. Although the invention is described in what are believed to be preferred embodiments, a wide variety of alternatives known to those expert in the art may be selected during the general description. Other advantages and obvious modifications of the invention will be apparent to an experienced person from the foregoing description and also from practice of the invention. The invention is not otherwise limited, except to list the claims set forth below.