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

PROCESS FOR MANUFACTURING HIGH RESISTANCE GLASS FIBERS BY DIRECT FUSION, AND PRODUCTS FORMED WITH THESE FIBERS

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention relates generally to a method of making continuous glass fibers for use in high strength applications and to products made with such fibers, such as shielding.

<td></td><td>ballistic.</td><td>the</td><td>reservors at</td><td>pressure, materials</td>

<td> 15</td><td>structural</td><td>for</td><td>aerospace</td><td>, marine materials</td>

<td></td><td>structural.</td><td>and</td><td>the materials</td><td>structural energy</td>

<td></td><td>wind turbine such</td><td>than</td><td>masts and</td><td>wind turbine blades.</td>

BACKGROUND OF THE INVENTION

Fiberglass reinforced composite materials have been available for use in marine and aerospace materials for some time. Other fiber materials such as carbon and aramid fibers are available for use, even at a significantly higher cost. Articles of the present invention may use any known manufacturing process, including compression molding, laminating, simultaneous spraying, hand molding, pre-fabricated (prepreg) draping, compress-2 molding. "32987Β1 sion, vacuum bag molding, pressure bag molding, press molding, transfer molding, vacuum assisted resin transfer molding, pultrusion molding, filament winding, casting, autoclave casting, centrifugal casting resin transfer and continuous casting. The properties of the composite are controlled by the fibers and the resin, and the synergy between the two, which produces material properties not available from the individual materials.

A number of resins are useful in the manufacture of composite articles including polyester resin, vinyl ester resin and epoxy resin. Polyester resin is suitable for a number of situations. Vinyl ester resin has lower viscosity pre-cure and smoother post-cure than polyester resin and is generally more resistant to degradation. Epoxy resin is generally transparent when cured. Epoxy resin is a polyether resin formed by the polymerization of bisphenol A, bisphenol F, bisphenol c, and compounds of similar structure with epichlorohydrin resulting in the formation of the reactive oxirane bond. Epoxy resins can react with a variety of curing agents including amines, anhydrides, mercaptans, polyesters to form a perfusable solid. The reaction is a condensation reaction which does not generally create any by-products. Cured epoxy resins have high strength and low shrinkage upon curing. They are used as

٠32987Β1

-3 coatings, adhesives, castings, composites or foam. Epoxy resins are also desirable for use in high strength applications as a structural matrix material or as a structural glue. Phenolics are thermosetting resins formed by the condensation of phenol or a derivative of phenol, with an aldehyde, generally a formaldehyde. Phenolics are used primarily in the manufacture of paints and plastics. Other specific high modulus resins include bismaleimide, polyamide, phenolic vinyl ester, ethylene-acrylate or methacrylate copolymers, high strength medium modulus thermoplastics such as ionomer (ie. i.e. an ethylene-methyl acrylate or crosslinked methyl methacrylate copolymer), polycarbonate, polyurethane, nylon,] aramid, modified epoxies.

The most common high strength glass composition for making continuous fiberglass strands is S-Glass. S-Glass is a family of glasses made up primarily of oxides of magnesium, aluminum and silicon with a chemical composition that produces glass fibers with higher mechanical strength than E-Glass fibers. A commonly used member of the S-Glass family is known as S2-Glass. The S2-G! Ass comprises about 65 wt% Sio25, ؛ wt% Al2O3, and 10 wt% MgO. SGlass has a composition that was originally designed for use in high strength applications

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-4such as ballistic armor.

R-Glass is a family of glasses that are composed primarily of oxides of silicon, aluminum, magnesium and calcium having a chemical composition that produces glass fibers with higher mechanical strength than EG fibers ! ass. R-Glass has a composition which contains about 58-60% by weight SO, 23.5-25.5% by weight AlHa, 14-17% by weight CaO plus MgO, 0% Β2Ο3.0 % F2 and less than 2% by weight of various components. R-Glass contains more alumina and silica than Ι'Ε-Glass and requires higher melting and processing temperatures during fiber formation. Typically, the melting and processing temperatures of R-Glass are at least 160 ° C higher than those of E-Glass. This increase in processing temperature generally necessitates the use of a high cost platinum-lined melting furnace. Further, the close proximity of the liquidus temperature to the R-Glass formation temperature requires the glass to be fiber at a higher temperature than E-Glass.

Other known high strength glass compositions can be found in US patent application Ser. No. 11 / 267,739 entitled Composition for

High Performance Glass, High Performance Glass Fibers and

Therefrom Articles (Composition for High Performance Glass. High Performance Glass Fibers and Articles

Formed With This Composition), published as US patent application Pub. No. 2008/0009403.

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Both R-Glass and S-Glass are produced by melting the constituents of the compositions in a platinum-filled melting container. The costs of forming R-Glass and S-Glass fibers are considerably higher than E-Glass fibers due to the cost of producing the fibers in such melting furnaces. Thus, there is a need in the art for methods of forming glass compositions useful in forming high performance glass fibers from a direct smelting process in a furnace substantially free of platinum or other noble materials and products. that come from it.

SUMMARY OF THE INVENTION

The present invention includes a process for producing refined glass from a mixture of raw glass with a glass melting furnace substantially free of platinum or other noble materials. The process includes loading a raw glass mixture destined for a melting zone of a glass melting furnace, melting the raw glass mixture in the melting zone and forming continuous fibers from the mass. fondue. The present invention also includes fibers formed by such a process, and products made from such fibers.

In one embodiment, the invention includes a method of forming high strength glass fibers in a continuous system having a furnace, a front body, and a socket. The method includes setting up an oven

ΜΑ '32987Β1

-610 glass melting for receiving the vitrifiable mixture and unloading the molten glass, and lining at least part of the furnace with a material substantially free of noble materials to form a contact surface of the furnace glass. The batch mix is ​​fed to the furnace, the batch mix being capable of forming molten glass convertible into fibers having a ΔΤ fiberization greater than 45٠F (25٥c) and for the production of glass fibers having a composition comprising about 50 'about 75 percent by weight of SO; about 15 about 30 weight percent AlO؟; about 5 - about weight percent MgO; about 0 - about 10 weight percent CaO; and about 0 - about 5 percent by weight of FO, where FO is equal to the sum of Li٠o, NO and

0. The batch mixture is melted in the furnace providing heat from a furnace heat source, such as oxy-fuel burners, forming a mass of molten glass in contact with the contact surface of the furnace glass. A front body is provided for transporting molten glass from the furnace to the socket, and at least a portion of the front body is lined with a material substantially free of noble materials to form a contact surface. glass of the fore-body. The molten glass is transported into the forearm while heat is supplied by a heat source in the forearm and circulates through the forearm along a substantially horizontal flow path formed by the surface. contact of the front body glass. Molten glass is released from the front body in the socket at a temperature of about 2i00 ° F (I316٥c) to about 29OO٥F

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-٦ (I593 ° C) and a predetermined viscosity (eg about 1000 poises), and is formed into continuous fibers.

The invention includes a method of making a glass composition for forming continuous glass fibers and products made from such fibers which are suitable for use in high strength applications. The compositions useful in the present invention can be economically formed into glass fibers at low cost, the direct melting being carried out in a furnace substantially free from platinum or other noble materials, including their alloys.

A composition useful in the present invention comprises 64-75% by weight SO, 16-26% by weight AlCq,

8-12% by weight MgO and 0-3.0% by weight FO 10 دان is the sum of L :. 0, Na2 &lt;3 and 0.

Another composition useful in the present invention comprises 64-75% by weight of SiOz, 16-24% by weight of AlCl, 8-12% by weight of MgO and 0.25 to 3.0% by weight of 10 where R2O is the sum of L10O, Na 2 O and KO. In some embodiments, the glass composition is comprised of 64-70% by weight SO, 17-22% by weight AOs, 9-12% by weight MgO and 1.75-3.0% by weight. weight of 10 where 0 is the sum of LizO, IaO and Κ2Ο. In another embodiment, a glass composition useful in the present invention is composed of 64-70% by weight of SiO2, 17-22% by weight of Al3, 9-12% by weight of MgO and 1.75. to 3.0% by weight of LiO.

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Yet another composition useful in the present invention comprises 50-75 ؛ by weight of si٥2, 13-30% by weight of AlCh, 5-20%. by weight MgO, 0-10 wt% CaO, 0-5 wt% FO where 10 is the sum of IiO, Na٦0 and Κ2Ο.

In some exemplary embodiments, the composition contains no more than about 5.0% by weight of compounds such as CaO, Ρ2Ο5, ZnO, zo, SrO, BaO, SO3, F, BO, ΤΟ2, FeO, Ce٠2 and BeC&gt; 2. In other exemplary embodiments, the composition is devoid of

CeÛ2 and BeO ؛ intentionally added. In yet other exemplary embodiments, the composition preferably contains no more than about 4% by weight of compounds or halogens such as ZnO, SO3, fluorine, Β2Ο3,

ΤΟ2, ZO and Fe₂O₃.

In certain exemplary embodiments, the desired properties of the high performance fibers made by the present invention include a fiberizing temperature of less than 265O٠F (1454٥C) and a liquidus temperature which is preferably below the fiberizing temperature of. at least 8O٠F (44٠c), more preferably at least about 12O٠F (67٠c), and preferably at least about 15O٠F (83٥C).

In other exemplary embodiments, the.

Desired properties of the high performance fibers made by the present invention include a fiberizing temperature of 24OO-29OO٥F (1316-1593٠c) and a liquidus temperature which is below the

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-9 fiberizing temperature of at least 45٠F (25٥c).

The present invention also provides a structural part having improved structural properties with lower costs and improved manufacturability. The direct melt formation of continuous glass fibers utilizes low cost melting in a glass melting furnace substantially free of platinum or other noble materials. The relatively low fiberizing temperature of the glass fibers used in the high strength applications of the present invention allows improved processing of the fibers at a reduced cost. Articles of the present invention are generally formed by compression molding, lamination, simultaneous spraying, hand molding, prefabricated draping (prepreg), compression molding, vacuum bag molding, pressure bag molding, press molding, molding. transfer, vacuum assisted resin transfer molding, pultrusion molding, filament winding, casting, autoclave molding, centrifugal casting resin transfer or continuous casting.

The fibers produced and used in the present invention are significantly less expensive to manufacture and also have good strength and density properties. The density of the fibers used in the present invention is between 2.434 and 2.520 g / cc, and more preferably between 2.434 and 2.486 g / cc and has a measured modulus greater than 12.7 MPsi and a strength of the primitive fiber measured greater than 680 KPsi.

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-10 BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a longitudinal sectional view of a glass melting furnace useful with the process of the present invention;

Fig. 2 is a cross-sectional plan view of the glass melting furnace of FIG. 1 socket along line 2--2;

Fig. 3 is a cross-sectional view of the glass melting furnace of FIG. 1 taken along line 3--3 showing two burners adjacent to the upstream end wall of the furnace;

Fig. 4 is another possible cross-sectional plan view of the glass melting furnace of FIG. 1 taken along line 3-_3 illustrating a burner adjacent to the upstream end wall of the furnace; and

Fig. 5 is a side view, partially in cross section, of a socket / support structure assembly arrangement for the production of continuous glass strands useful in the process of the present invention.

Fig. 6 is a top plan view in cross section of a front body taken as an example useful in the process of the present invention for transporting molten glass from the glass melting furnace to

ΜΑ 32987Β1

-11! Socket / support structure assembly.

Fig. 7 is a side elevational view in cross section of another front part taken as an example useful in the process of the present invention.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF

THE INVENTION

The present invention will now be described with occasional reference to specific embodiments of the invention. This invention can, however, be practiced in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided for the purpose of this description to be complete and thorough, and will communicate the scope of the invention to those skilled in the art.

Unless defined otherwise, all technical and scientific terms used in this document have the same meaning as that commonly understood by a person skilled in the art to whom this invention belongs. The terminology used in the description of the present invention is to describe the particular embodiments only and is not intended to be limiting.

<td></td><td>of the invention.</td><td>As used in the</td><td>description</td><td>of</td>

<td></td><td>! 'invention and</td><td>the appended claims</td><td>, shapes</td><td> ^11</td>

<td></td><td>singular one.</td><td>one and the are</td><td>supposed incl</td><td>ure</td>

<td> 30</td><td>forms at</td><td>plural also, except</td><td colspan="2">if the context</td>

MA '32987Β1

-12 clearly indicates the opposite.

Unless otherwise indicated, all numbers expressing amounts of ingredients, properties such as molecular weight, reaction conditions, and the like as used in the specification and claims are to be understood as being modified throughout. cases by the term approx. Therefore, unless otherwise indicated, the numerical properties set forth in the specification and the claims are approximations which may vary depending on the desired properties sought to be achieved in embodiments of the present invention. Notwithstanding that the number plates and parameters indicating the wide scope of the invention are approximations, the numerical values ​​set forth in the specific examples are reported as accurately as possible. All numeric values, however, inherently contain certain errors necessarily resulting from an error in their respective measurements.

The fiberizing properties of the glass composition used to form the glass fibers of the present invention include fiberizing temperature, liquidus and delta-T. Unless defined otherwise in this document, the fibraqe temperature is defined as the temperature which corresponds to a viscosity of 1000 poises (temperature loq 3). One skilled in the art will recognize that other fiberizing temperatures can be defined, for example, a fiberizing temperature can be defined as

ΜΑ 32987Β1

-13the temperature which. corresponds to a viscosity of 316 poises (temperature log 2.5).

As discussed in more detail below, in some embodiments, a lowered fiberizing temperature reduces the cost of fiber production, allows a longer life of the sleeves, increases the production capacity, allows the glass to dye. be melted in a melting furnace practically free from platinum or other noble materials, and reduce the use of energy. For example, at a lower fiberizing temperature, a socket operates at a cooler temperature and does not flex as quickly. Sagging is a phenomenon which occurs in sockets which are held at a high temperature for long periods of time. By lowering the fiberizing temperature, the sag rate of the sleeve can be reduced and the life of the sleeve can be increased. In addition, a low fiberizing temperature allows for a higher production capacity since more glass can be melted in a given period of time at a given energy input. As a result, the production cost is reduced. Further, a low fiberizing temperature will also allow the formation of a glass having the inventive method and composition to be melted in a refractory-lined melting furnace, or a melting furnace having walls cooled on the outside, being given that both its melting and fiberizing temperatures are below the higher operating temperatures of many refractories or other materials available on

ΜΑ 32987Β1

-14 the market when external cooling is applied.

Liquidus is defined as the highest temperature at which equilibrium exists between liquid glass and its primary crystalline phase. At all temperatures above liquidus, glass is free of crystals in its primary phase. At temperatures below liquidus crystals can form.

Another fiberizing property is delta-T (ΔΤ), which is defined as the difference between the fiberizing temperature and the liguidus. A larger ΔΤ provides a greater degree of flexibility in glass fiber formation and helps inhibit glass devitrification (i.e., crystal formation in the melt) during melting and fiber drawing. . Increasing ΔΤ also reduces the cost of producing glass fibers by allowing longer bush life and providing a wider process window for fiber formation.

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

The glass compositions used in the present invention are advantageously suitable for melting in a furnace or melting furnace substantially free of glass.

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-15 platinum or other noble materials and their alloys, including traditional commercially available refractory-lined glass melting furnaces, and commercially available exterior-cooled wall-lined glass melting furnaces, such as .ex.watercooled walls.

The starting mix components generally include SiC&gt; 2 (crushed silica sand), and ΙΆΙ2Ο3 (calcined alumina), Li2CO3 (lithium carbonate), Η3ΒΟ3 (boric acid), NaCaBsCSO (ulexite), 2CaO- 3B2٥3-5H2O (colemanite) as well as chain modifiers from basic materials such as MgC (magnesite), CaO (limestone), SrO (strontianite), BaO (witherite), ZrSO (zircon), and Na2C٠3 (natrite).

Those skilled in the art will appreciate that other starting materials can be used. Other non-limiting examples of suitable starting mixture components include kaolinite (Al₂Yes₂O₅ (OH) 4), pyrophyllite (AlSiOo (OH) 2), bauxite (A1O (OH)), wollastonite (CaSO), spodumene (LiAlSi2Og), feldspar (CaAl2Si2Og), dolomite (CaMg (002) 2), lime (CaO), dolomitic quicklime (CaMg02١, and hydrated lime (Ca (OH) 2).

Glass Melting Furnace

Figs 1-4 show a glass melting furnace (10) useful in the glass fiber forming process described and shown in the Examples and Cations below. It may also be desirable

MA 32987Β1

-1610 to use oxygenated heating in the melting furnace, as described in US Pat. No. 7,509,819 entitled OXYGEN-FIRED FRONT END FOR GLASS FORMING OPERATION de Verre), inventors David j Baker et al., incorporated herein by reference in its entirety. The glass melting furnace (10) supplies the molten glass to a glass front body (12).

In an exemplary embodiment, the molten glass is comprised of 50-75 wt% SO, 13-30 wt% Al2O3, 5-20 wt% MgO, 0-10 wt% CaO, 0 to 5% by weight of R2O where R2O is the sum of IiO, Na2٥ and KO. This exemplary embodiment includes glass compositions having a higher fiberizing temperature, for example, 2400-2900٠F (1316-1593٠C) and / or a mistletoe li temperature is below the fiberizing temperature of only 45٠F (25٠C).

In another exemplary embodiment, the molten glass is composed of about 64-75 wt% Si٠2, 16-26 wt% Al2O3, 8-12 wt% MgO, and 0-3.0%. by weight of R2O where R2O is the sum of Li2٥, Na2Ü and Κ2Ο.

In yet another exemplary embodiment, the molten glass is composed of about 64-75 wt% Si٠2, 16-24 wt% Al2O3, 8-12 wt% MgO and

0.25-3.0% by weight of R ؛ o where R ؛ o is the sum of Li₂0, Na2٥ and O. A fiber made in accordance with the process of this

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An exemplary embodiment will have a fiberizing temperature of less than 265O ° F (1454٥0), and in some embodiments less than about 2625٠F (I458٠c), in other embodiments less than about 26OO٥F (1427٠C) and in some embodiments some embodiments less than about 2575٥F (1413٠C) and a liquidus temperature that is below the fiberizing temperature in some embodiments of at least 8O٥F (44٠Ο, and in other embodiments of at least about 12O٥F (67٥c), and in still other embodiments of at least about 15O٠F (83٥C).

In yet another exemplary embodiment, the molten glass is comprised of 50-75 wt% SiC&gt; 2, 1315 wt% A103, 5-20 wt% MgO, 0-10 wt% of CaO, 0 to 5% by weight of 10 where R2O is the sum of LO, Na2O and Κ2Ο. This exemplary embodiment includes glass compositions having a liquidus temperature which is above the log 3 fiberizing temperature, i.e. a negative ΔΤ such as -122٠F (_68٠Ο). Such a composition can be fiberized at a higher temperature, for example a fiberizing temperature of 2.5 corresponding to a viscosity of 316 poises.

In some exemplary embodiments, the composition contains no more than about 5.0% by weight of oxides or compounds such as CaO, Ρ2Ο5, ZnO, zo, SrO, BaO, SO3, fluorine, Β2Ο3, TO, Fe2O3, Κ2Ο, Ce02 and BeO₂٠ In other exemplary embodiments, the composition is devoid of Ce02 and BeO₂ intentionally added.

I

32987Β1

The fibers produced and used in the present invention are significantly less expensive to manufacture and also have good strength and density properties. The density of the fibers used in the present invention is between 2.434 and 2.520 g / cc, and more preferably between 2.434 and 2.486 g / cc. Further, the glass fibers of the present invention, in some embodiments, will have a pitch fiber strength that exceeds 680 KPSI, and in some other embodiments a strength that exceeds about 700.

KPSI, and still in other embodiments a resistance which exceeds about 730 KPSI. Further, the glass fibers will advantageously have a modulus greater than 12.0 MPSI, and in some embodiments greater than about 12.18 MPSI, and in some embodiments greater than about 12.7 MPSI.

The method of the present invention is preferably carried out using the glass melting furnace (10), which comprises an elongate channel having an upstream end wall (14), a downstream end wall (16), walls. side (18), a sole (20), and a roof (22). Each of the components of the glass melting furnace (10) is made from suitable refractory materials such as alumina, chromic oxide, silica, aluminesilica, zircon, zirconia-alumina-silica, or Similar oxide-based refractory materials, especially surfaces which are in contact with molten glass. The roof (22) is generally shown to have an arcuate shape transverse to the longitudinal axis of the roof.

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إ

-19channel composition; however, the roof can be any suitable design. The roof (22) is generally positioned about 3-10 feet above the surface of the batch mix (30). The batch mixture (30) is a mixture of raw materials used in the manufacture of glass in accordance with the present invention.

The glass melting furnace (10) may optionally include one or more bubblers (24) and / or electrical booster electrodes (not shown). The bubblers (24) and / or electric booster electrodes increase the temperature of the bulk glass and increase the flow of molten glass under the cover of the mixture.

The bubblers (24) and / or the electric booster electrodes may be particularly useful in the second and third exemplary embodiments, which comprise glass compositions having a temperature ؛ higher fiberization, for example, 2400-2900٠F (13161593٠C) and / or a low ΔΤ, for example as low as 45٠c

<td></td><td>(25٥F), or even</td><td>a negative ΔΤ</td><td>Phone</td><td>that: -122٠F 1</td><td>I-68٥C), where</td>

<td></td><td>the potential of</td><td>devitrification</td><td>is</td><td>bigger.</td><td></td>

<td> 25</td><td>In addition</td><td>, the oven of</td><td colspan="2">glass melting</td><td>(10) can</td>

<td></td><td>have two</td><td colspan="2">successive zones,</td><td>an area of</td><td>fusion in</td>

upstream (26) and a downstream refining zone (28). In the melting zone (26), the batch composition (30) can be loaded into the furnace using a loader (32) of a type well known in the art.

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-20 In a suitable melting furnace configuration, the glass melting material (30) forms a solid particle mixture layer on the surface of the molten glass in the melting zone (26) of the glass melting furnace (10) ٠ The floating particles of the solid mixture of the batch composition (30) are at least partially melted by at least one burner (34) having a controlled flame shape and a length mounted in the roof (22) of the glass melting furnace ( 10).

In a preferred embodiment, as shown in FIG. 1, the glass melting furnace (10) comprises three burners (34). An individual burner (34) is positioned upstream of two burners (34) positioned adjacent downstream. However, it will be appreciated that any number of burners (34) can be placed at any suitable location in the roof (22) of the furnace (10) on the mixture to melt the glass mixture (30). For example, two burners (34) can be placed in a side-to-side relationship (Figure 3) or a single burner can be used (Fig. 4).

It should be noted that the burners (34) of the glass melting furnace (10) can be arranged in the vault (roof) of the furnace, in the side walls, the end walls, immersed in the mixture or in molten glass , or in their combinations.

Other melting furnaces can be used without departing from the present invention. Melting furnaces

ΜΑ 32987Β1

..

Suitable include air-gas smelters, oxygen-gas smelters, electric smelters, or any smelting furnace heated by fossil fuels. It is possible to add electrical back-up or bubblers to one of the fusion processes.

It is also possible to include a separate refining zone (as shown in Fig. 1) or to incorporate the refining zone into the main tank of the melting furnace.

Avant-corps arrangement

The fore-body receives the molten glass discharged from the glass melting furnace and conveys the molten glass, discharging the molten glass under conditions suitable to a forming position. The front body components can be lined with suitable refractory materials such as alumina, chromic oxide, silica, alumina-silica, zircon, zirconia-alumina-silica, or similar refractory materials. oxide-based, especially surfaces which are in contact with molten glass. Preferably, such front body glass contact surfaces are lined with chromic oxide, zircon, or combinations thereof.

For compositions having a fiberizing temperature of less than 265O٥F (I454٥c) and a mistletoe temperature below the fiberizing temperature of at least 8O٥F (44٠C), a conventional forehearth can be used.

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ؤ

-2210

For other compositions where the fiberizing temperature is high and / or the ΔΤ is low, other fore-body arrangements may be useful in promoting an isothermal condition in the molten glass, thereby preventing devitrification. For example, transporting molten glass through the forehearth to a shallow depth (D), for example less than about 8 inches, or preferably less than about 3.5 inches, will improve the transmission of water. heat by emission through molten glass. The installed oxygen-fuel burners are particularly useful as a front body heat source in this regard. A typical oxygen-fuel heating system is supplied by BH-F (Engineering) Ltd of England. As defined here, oxygen-fuel burners are burners that use oxygen (eg, typically 90 to 99 percent purity with an impurity being a combination of nitrogen and argon) in high purity. as an oxidant, instead of the ambient air used in air-fuel burners, and fossil fuel for a fuel hydrocarbon feed, but may include oxygen enriched air burners (eg 30 to 90 percent purity). The flame temperature of an oxygen-gas burner is about 4200 to about 52OO٥F (about 2315 to about 2871 ° C). At this temperature, the flame and the products of combustion emit energy at wavelengths that molten glass can absorb. This promotes a constant temperature of the glass horizontally over the surface of the molten glass and vertically across the molten glass.

ΜΑ 32987Β1

-23 Air-fuel burners can also be used as a front body heat source, especially when installed with very tight spacing, for example, 4 inches apart.

Typical front panel arrangements useful in the present invention are shown in Figs. 6 and

7. The fore-body (322Α) is adapted to deliver a molten substance (e.g. molten glass G) from a glass melting furnace to a production point (e.g., a forming position, discussed below ). The molten glass (G) does not come into contact with an upper part of the front body (322Α). Therefore, this part can be constructed from relatively inexpensive refractory material (eg, superstructured refractory material, such as silica, mullite, or other materials which do not need to withstand the corrosive effects. molten glass (G)).

A lower portion of the front body (322Α) is below the glass level (L) and thus forms a glass contact surface which comes into contact with the molten glass (G). Therefore, this front body part (322Α) is constructed of more expensive glass contact material. A refractory ceramic material (ie, zircon, chromic oxide, or other suitable materials) is a suitable refractory contact glass material because it can withstand the corrosive effects of molten glass (G).

ΜΑ 32987Β1

: أ

-24The fore-body (322Α) may include an upper part or vault (not shown), a bottom (also إ not shown), and the side walls (328Α). The forearm (322Α) has an upstream end, usually indicated at

33) 5 ؛ ΟΑ), and a downstream end, usually indicated at (332Α). An open end (334) may be disposed at the downstream end (332Α) of the front body (322Α). An end wall (336Α) may be disposed at the upstream end (33ΟΑ) of the front body (322Α). One or more glass orifices (338) may be provided at the bottom of the front body (322Α) near, adjacent or close to the end wall (336Α). The front end fore-body, as shown above, is the portion of the front-end (322Α), having the end wall (336Α) and the glass holes (338) at the bottom.

Front body burners (344), such as oxygen-fuel burners, are positioned above the glass level (L), shown in Fig. 7. The front body burners (344) are oriented in a plane (eg, a substantially horizontal plane) perpendicular to the surfaces (340) and at an acute angle to the surfaces (340). The front body burners (344) are pointed toward the downstream end 332Α of the front body (322Α) إ at an angle of between about 5 degrees and about 85 degrees to the surfaces (340) as shown. in Fig. 6. The front body burners (344) can be offset or spaced so that the opposing front body burners (344) in the opposing side walls (328Α) are laterally offset or do not line up.

-32987Β1

<img file="MA32987B1_D0001.tif" />

-٦5 laterally (do not line up vertically when looking at Fig. 6) of each other.

The flame temperature of a fuel oxygen burner is approximately 4200-5200٥c. However, the flame is preferably very weak. Therefore, the flame does not come into direct contact with the side walls (328Α). However, the radiant heat of the flame is quite substantial. Although the flame does not come into direct contact with the side walls (328Α), the side walls (328Α) are sufficiently heated by convection or otherwise by the radiant heat of the flame. This radiant heat is sufficient to properly condition the molten glass (G) and maintain the molten glass G at a desired temperature without compromising

The integrity of the front body (322Α) by exposing the front body (322Α) to excessively high temperatures. This is true even though the burners (344) are about 1 foot to about 5 feet apart from each other.

It should be noted that other arrangements of fore-body burners are possible and fall within the scope of the invention. For example, another exemplary burner arrangement is illustrated in FIG. 7. The front body burners (344) are oriented in a plane (eg, a substantially vertical plane) perpendicular to the surface (346) and at an acute angle to the surface (346). The forearm burners (344) may be pointed toward the upstream end 33OC of the channel (322C) at an angle between about 5 degrees and about

ΜΑ 32987Β1

-2685 degrees from surface 346, as shown in Fig. 7. Alternatively, the forearm burners (344) can be pointed toward the downstream end (332C) of the channel (322C) at an angle between about 95 degrees and about 175 degrees to the surface (346).

It should be noted that the burners can be arranged in the vault (roof) of the front body, in the side walls, the end walls, immersed in the mixture or molten glass, or in their combinations.

Bushing Assembly

As shown in Fig. 5, a socket assembly 100 includes a socket (110) and a socket frame 210. The socket (110) includes a socket main body (120) having side walls (122) and a tip plate (124) extending between the side walls (122). The main body (120) is positioned below a socket block (300) which, in turn, is placed under a front body (310). Using the method of the present invention, a stream of molten glass is received by the main body (120) of the front body (310). The front body (310) receives molten glass from a melting furnace (10) (shown in Fig. 1.). A delivery channel (40) is positioned between the melting furnace (10) and the front body (310) to deliver the molten batch mix composition (30) from the melting furnace (10) to! 'fore-body (310). The front body (310) and the socket block (300) may be of construction

ΜΑ -32987Β1

-Ί٦ classic and can be formed from refractory materials.

The tip plate (124) contains a plurality of nozzles (I24a) (also referred to as orifices) through which a plurality of streams of molten glass can be vented. Streams of molten material can be drawn mechanically from the tip plate (124) to form continuous filaments (125) via a conventional winding device (400) such as a winder or chopper or other attenuation means. The filaments (125) can be combined into one or more continuous strands (125a), after having saturated a protective layer of a sizing composition from a sizing applicator (410).

The continuous filaments (I25a) can be wound onto a rotating mandrel (402) of the winding device (400) to form a bundle (I25b). The continuous filaments (125) can also be made into other desired composite glass materials including, without limitation, wet-use chopped strand fibers, dry-used chopped strand fibers, continuous filament mats, etc. mats of cut strands, wet formed mats or mats exposed to air.

The high strength articles of the present invention utilize the formed fibers described above as a glass fiber reinforcement in a polymer matrix material. Typical matrix materials include epoxies, phenoplasts, vinylesters, and polyesters. Articles can be shaped by any

ΜΑ '32987Β1

-28 ن ؛ .

إ what suitable manufacturing technique including compression molding, rolling, simultaneous spraying, hand molding, prefabricated draping (prepreg), compression molding, vacuum bag molding, pressure bag molding, press molding, transfer molding, vacuum assisted resin transfer molding, pultrusion molding, filament winding, casting, ؛ molding autoclave, centrifugal casting resin transfer and continuous casting.

Having generally described this invention, further understanding can be obtained by reference to certain specific examples illustrated below which are provided for illustrative purposes only and are not intended to be all inclusive or limiting unless otherwise indicated.

''

EXAMPLES

The glasses in the examples listed in Tables IIA - lie were melted in platinum crucibles or in a continuous platinum-lined melting furnace to determine the mechanical and physical properties of the glass and the fibers made therefrom. The units of measure for the physical properties are as follows: Viscosity (° F), Liquidus temperature

٠) ؤ F) and the ΔΤ (٥F). In some examples, the glasses were fiberized and the Resistance (KPsi), Density (g / cc), and Modulus (MPsi) were measured.

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The fiberizing temperature was measured using a rotating mobile viscometer. The fiberizing viscosity is defined as 1000 poises. Liquidus was measured by placing a platinum container filled with glass in a thermal gradient oven for 16 hours. The highest temperature at which crystals were present was considered the liquidus temperature. The modulus was measured using sound technique on a single fiberglass. The tensile strength was measured on a single primitive fiber.

Table IIA

<td>Glass</td><td>Ex. 1</td><td>Ex. 2</td><td>Ex. 3</td><td>Ex. 4</td><td>Ex. 5</td><td>Ex. 6</td>

<td>SO</td><td> 67,2</td><td> 69</td><td> ٦&lt;؟</td><td> 70</td><td> 70</td><td> 65</td>

<td>2٠3 ا ٨</td><td> 20</td><td> 22</td><td> 22</td><td> 17</td><td> 17</td><td> 21</td>

<td>MgO</td><td> 9,8</td><td> 9</td><td> 11</td><td> 11</td><td> 10</td><td> 11</td>

<td>LO</td><td> 3</td><td> 0</td><td> 0</td><td> 2</td><td> 3</td><td> 3</td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Measured Viscosity (٥F)</td><td> 2531 (1388)</td><td> 2761 (1516)</td><td> 2648 (1453)</td><td> 2557 (1403)</td><td> 2558 (1403)</td><td> 2461 (1349)</td>

<td>٩٠٢ Liquidus Measurement (٠F)</td><td> 2313 (1267)</td><td> 2619 (1437)</td><td> 2597 (1425)</td><td> 2332 (1278)</td><td> 2302 (1261)</td><td> 2296 (1258)</td>

<td>2٥٠ Measured Liquidus (٥F)</td><td> 2302 (1261)</td><td> 2620 (1438)</td><td> 2614 (1434)</td><td> 2346 (1286)</td><td> 2308 (1264)</td><td> 2318 (1270)</td>

<td>Δ1 (° F)</td><td> 218 (121,1)</td><td> 142 (78,89)</td><td> (28,33)</td><td> 225 (125)</td><td> 256 (142,2)</td><td>165 (91.67) لذ</td>

<td>Measured Density (g / cc)</td><td> 2,459</td><td> 2,452</td><td> 2,481</td><td> 2,450</td><td> 2,441</td><td> 2,482</td>

Table ΙΙ-Β

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<td>Glass</td><td>Ex. 7</td><td>Ex. 8</td><td>Ex. 9</td><td>Ex. 10</td><td>Ex. 11</td><td>Ex. 12</td>

<td>SO</td><td> 70</td><td> 69</td><td> 70</td><td> 65</td><td> 66</td><td> 65</td>

<td>3 ه 2 ا ٨</td><td> 18</td><td> 17</td><td> 21</td><td> 22</td><td> 22</td><td> 22</td>

<td>0 لأللي ١</td><td> 9</td><td> 11</td><td> 9</td><td> 11</td><td> 9</td><td> 10</td>

<td>ه 2 لا</td><td> 3</td><td> 3</td><td> 0</td><td> 2</td><td> 3</td><td> 3</td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Measured Viscosity ٠F (٠c)</td><td> 2544 (1396)</td><td> 2496 (1369)</td><td> 2752 (1511)</td><td> 2525 (1385)</td><td> 2523 (1384)</td><td> 2486 (1363)</td>

<td>1®'Measured Liquid ٠F (٠C)</td><td> 2311 (1266)</td><td> 2234 (1223)</td><td> 2597 (1425)</td><td> 2468 (1353)</td><td> 2391 (1311)</td><td> 2361 (1294)</td>

<td>2nd Liquidus Measure ٠F (٥c)</td><td> 2324 (1273)</td><td> 2343 (1284)</td><td> 2603 (1428)</td><td> 2462 (1350)</td><td> 2394 (1312)</td><td> 2382 (1306)</td>

<td>ΔΤ ٠F (٠C)</td><td> 233 (129,44)</td><td> 262 (145,56)</td><td> 155 (86,11)</td><td> (31.67)</td><td> 132 (73,33)</td><td> 125(69,44)</td>

<td>Measured Density (gcc)</td><td> 2.434</td><td> 2,455</td><td> 2,443</td><td> 2,486</td><td> 2,460</td><td> 2,474</td>

Table II-C

<td>Glass</td><td>Ex. 13</td><td>Ex. 14</td><td>Ex. 15</td><td>Ex. 16</td><td>Ex. 17</td><td>Ex. 18</td>

<td>Si٥2</td><td> 70</td><td> 67,32</td><td> 67,57</td><td> 68.27</td><td> 68,02</td><td> 67,76</td>

<td>AIO</td><td> 19</td><td> 20,49</td><td> 20.49</td><td> 20,10</td><td> 20,10</td><td> 20,10</td>

<td>MgO</td><td> 11</td><td> 10,00</td><td> 10,00</td><td> 9,69</td><td> 9,69</td><td> 9,69</td>

<td>LisO</td><td> 0</td><td> 2,00</td><td> 1,75</td><td> 1.75</td><td> 2,00</td><td> 2,25</td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Measured Viscosity ٠F (٠C)</td><td> 2679 (1471)</td><td> 2563 (1406)</td><td> 2584 (1418)</td><td> 2598 (1426)</td><td> 2578 (1414)</td><td> 2547 (1397)</td>

<td>1 Liquidus Measure ٠F (٠C)</td><td> 2596 (1224)</td><td> 2456 (1347)</td><td> 2486 (1363)</td><td> 2446 (1341)</td><td> 2431 (1333)</td><td> 2399 (1315)</td>

<td>2nd Liquidus Measure “F (٠C)</td><td> 2582 (1417)</td><td> 2447 (1342)</td><td> 2469 (1354)</td><td> 2469 (1354)</td><td> 2437 (1354)</td><td> 2406 (1319)</td>

<td>۵T٠F (٠C)</td><td> 83 (46,11)</td><td> 111,5 (61,94)</td><td> 106,5 (59,17)</td><td> 140,5 (78,05)</td><td> 144 (80)</td><td> 144,5 (80,28)</td>

<td>Measured Density (gcc)</td><td> 2,453</td><td></td><td> 2,461</td><td></td><td> 2.452</td><td></td>

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Compositions useful in the present invention can also include chain modifiers such as Na2٥, CaO and Β2Ο3. These compositions are shown in Table IID (below).

HD Table

<td>1st</td><td>Ex. 19</td><td>Ex. 20</td><td>2٦ ة</td><td>Ex. 22</td><td>Ex. 23</td><td>Ex. 24</td>

<td>Si٠2</td><td> 75</td><td> 66</td><td> 65</td><td> 65</td><td> 66</td><td> 74</td>

<td>Α12Ο3</td><td> 15</td><td> 20</td><td> 20</td><td> 24</td><td> 19</td><td> 15</td>

<td>MgO</td><td> 8</td><td> 9</td><td> 8</td><td> 8</td><td> 9</td><td> 8</td>

<td> 10</td><td> 1</td><td> 1</td><td> 2</td><td> 0</td><td> 0</td><td> 0</td>

<td>NO</td><td> 1</td><td> 2</td><td> 1</td><td> 1</td><td> 2</td><td> 3</td>

<td>CaO</td><td></td><td> 2</td><td> 4</td><td></td><td></td><td></td>

<td>Β2Ο3</td><td></td><td></td><td></td><td> 2</td><td> 4</td><td></td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Measured Viscosity "F (" C)</td><td> 2765 (1518)</td><td> 2607 (1431)</td><td> 2469 (1354)</td><td> 2669 (1465)</td><td></td><td> 2809 (1543)</td>

<td>1®٢ Liquidus Measured ٥F (٠c)</td><td> 2422 (1328)</td><td> 2729 (1498)</td><td></td><td> 2614 (1434)</td><td> 2630 (1443)</td><td> 2680 (1471)</td>

<td>ΔΤ ٠F (٠c)</td><td> 343 (190,55)</td><td> -122 (-67,78)</td><td></td><td> 55 (30,56)</td><td></td><td> 129 (71,67)</td>

The fibers produced by the present invention have superior modulus and strength characteristics. The fibers of Example 1 have a measured modulus of 12.71 MPsi and a measured strength of 688 KPsi. The fibers of Example 3 have a measured modulus of 12.96 MPsi and a measured resistance of 737 KPsi. The fibers of Example 17 have a measured modulus of 12.75 MPsi and a measured resistance of 734 KPsi.

ΜΑ 32987Β1

As is understood in the art, the above exemplary inventive compositions do not always total 100% of the listed components due to statistical conventions (such as, rounding and averaging) and the fact that that some compositions may include impurities which are not listed. Of course, the actual amounts of all components, including any impurities, in a composition always add up to 100%. Further, it should be understood that where small amounts of components are specified in the compositions, for example, amounts on the order of about 0.05 weight percent or less, these components may be present below the form of trace impurities present in raw materials, rather than intentionally added.

Further, components can be added to the composition of the mixture, for example, to facilitate processing, which are then removed, thereby forming a glass composition which is essentially free of such components. Thus, for example, minute amounts of components such as fluorine and sulfate may be present as trace impurities in the raw materials providing the components of silica, lithina, alumina, and magnesium oxide in commercial practice of invention or they can be processing aids which are essentially lost in the process of manufacture.

As can be seen from the examples above, some

MY

-32987Β1

Glass fiber compositions useful in the invention have valuable properties, such as low fiberizing temperatures and large differences between liquidus temperatures and fiberizing temperatures (high ΔΤ values). Other obvious advantages and modifications of the invention will be apparent to those skilled in the art from the above description and others from the practice of the invention).

In some embodiments, the high performance glass produced by the present invention melts and clarifies at relatively low temperatures, has a viscosity achievable over a wide range of relatively low temperatures, and a low temperature range of

Iiguidus.

The invention of the present application has been described above both genetically as well as with regard to specific embodiments. Although the invention has been set forth in what are intended to be the preferred embodiments, a wide variety of alternatives known to those skilled in the art can be selected from the generic disclosure. Other obvious advantages and modifications of the invention will be apparent to those skilled in the art from the above description and also by the practice of the invention. The invention is not otherwise limited except for the claims set forth below.