CA1193290A - Fiber glass composition - Google Patents
Fiber glass compositionInfo
- Publication number
- CA1193290A CA1193290A CA000421883A CA421883A CA1193290A CA 1193290 A CA1193290 A CA 1193290A CA 000421883 A CA000421883 A CA 000421883A CA 421883 A CA421883 A CA 421883A CA 1193290 A CA1193290 A CA 1193290A
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- Canada
- Prior art keywords
- weight
- oxide
- glass
- amount
- fiber glass
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C13/00—Fibre or filament compositions
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Glass Compositions (AREA)
Abstract
Abstract of the Disclosure The fiber glass has a composition consisting essentially of:
APPROXIMATE
RANGES % BY
WEIGHT
Si02 53 to 63%
A12O3 3 to 7%
B2O3 5 to 10%
Na2O 10 to 15.5%
K2O 0 to 2.5%
CaO 6 to 12%
MgO 0 to 6%
BaO 0 to 6%;
the composition additionally including one or the other or both of, by weight, Li2O up to about 2%
F up to about 1.2%;
the aggregate amount of the Na20 and Li20 not exceeding about 16.4% by weight, the aggregate amount of the Na20, K20 and Li2O not exceeding about 18% by weight, the aggregate amount of the CaO, MgO and BaO being from about 8% by weight to about 18% by weight, of which at least about 60% is CaO, and the aggregate amount of Li2O
and F being at least about .4% by weight.
APPROXIMATE
RANGES % BY
WEIGHT
Si02 53 to 63%
A12O3 3 to 7%
B2O3 5 to 10%
Na2O 10 to 15.5%
K2O 0 to 2.5%
CaO 6 to 12%
MgO 0 to 6%
BaO 0 to 6%;
the composition additionally including one or the other or both of, by weight, Li2O up to about 2%
F up to about 1.2%;
the aggregate amount of the Na20 and Li20 not exceeding about 16.4% by weight, the aggregate amount of the Na20, K20 and Li2O not exceeding about 18% by weight, the aggregate amount of the CaO, MgO and BaO being from about 8% by weight to about 18% by weight, of which at least about 60% is CaO, and the aggregate amount of Li2O
and F being at least about .4% by weight.
Description
~IBER GLASS CO~POSITION
Technical Field The subject matter of the present invention is a glass fiber composition havin~ particular utility for fiber ~lass insulation.
Back~round Art Fiber glass, and particularly that used as thermal i~lsulation, is commonly made by the so-called rotary m~thod wherein molten glass is fed onto a rotating spinner having a cylindrical peripheral wall with closely spaced small openings therethrou~h, centrifugal force causing the glass to flow through the openings thereby at least to initiate the formation of the glass fibers.
Conventionally the openings are of a diameter considerably larger than that desired for the final fibers, a reduction in the diameter of the initially formed fiber~ belng attained by attenuation, as by a blast of hot g~8 against the fibers in a direction ~enerally perpendicular to the plane of rotation of the spinner. In another rotary method, that cvvered by U.S. Patent No. 4,058,386, the size of the openin~s and the other parameters of the spinner and method are such that the glass fibers as initially formed are already of extremely small diameter to the end that their attenuation by a hot blast of gas is not mandatory.
This is advantageous in that it eliminates a reguirement for the hi~h ener~y costs involved in providing a continuous hot ~as blast essential to the older method to attain fibers of the small diameter desired for fiber glass insulation.
Both methods reguire that various of the properties of the glass, such as its softening point, its Liguidus temperature and its viscosity at the temperature at which it i8 fed onto the spinner, be within ralatively narrow limits. On the other hand, it iB also important that the glass composition be such as to provide a high ~uality, durable fiber glass insulation product. A lon~ standin~
problem has been that these respective parameters for the processing of the gla~s into fibers and for the characteristics of the manufactured fiber glass product are in conflict. That is, when the ~lass composîtion is formulated in the direction of providing those characteristics needed for efficient fiberizing with a spinner, there i~ compromi~e as regard~ those charPcteristics required for Q good, durable fiber glass product and, vice versa, if the glass i~ formulated in the direction of providing optimum characteristics for the fiber glass product, then there is compromise in the attainment of those characteristics necessary or desirable for rotary fiberiæinG.
Superimposed on all of this i9 the further practical reguirement that the glass composition not be too expensive and hence not contain large amounts, if any, of expensive in~redients. Particularly taking into account this latter consideration, there are only a limited number of raw materials which lend them3elves well as ingredients for the formulation of ~lass for fiber glass insulation, and all or most of them have been used time and a~ain in differing combinations and in differin~ proportions. This would be discouraging but for the further act that even sm~ll differences in the combinations or proportions of ingredients used can result in quite si~nificant differences in properties, and often unpredictably. The solution to the aforesaid problems resides in discovering glass fiber compositions wherein the combination of ingredients and the proportions thereof are such as to provide, at low cost, the vsrious properties desired both for the final product and for its rotary fiberization.
The present invention provides such a glass fib2r composit;on for rotary fiberiz~tion.
Brief Description of the Invention The ~lass fiber composition of the present invention consists essentially of ~PPROXI~ATE
RANGES % BY
WEIGHT
SiO2 53 to 63%
A1203 3 to 7%
B203 5 to 10%
Na20 10 to 15.5%
K20 0 to 2.5 CaO 6 to 12 MgO O to 6~
BaO O ~o 6~;
~1 ~3~
the composition additionally includin~ one or the other or both of, by weight, Li20 up to about 2~, F up to about 1.2'~;
the aggregate amount of the Na20 and Li~O n~t exceeding about 16.4~ by weight, the aggregate amount of the Na20, K20 and Li20 not exceeding about 18~ by weight, the aggregate ~mount of the CaO, MgO and BaO being from about 8% by weight to about 18~ by weight, of which at least about 60% i5 CaO, and the a~gregate ~aount of the Li20 and F being at least about .4% by weight.
The glass has a softening temperature of from 1150`~ to 1230`F and a Liquidus temperature of from 1750`F to 1815'F.
The fiber ~la55 insulation is made by feedit~ the molten glass of the above composition onto a spinner which i~ preferably at a tamperature of from about 2000`F to 7100`F. The visc~si~y and flow characteristics oE the ~lass are compatible with methods of rotary ~iberization which, in their particulars, may vary cot~siderably, but the ~lass is particularly advanta~eous for use in a rotary method as exemplified in the aforementioned U.S. Patent No. 4,058,3B6. The glass
Technical Field The subject matter of the present invention is a glass fiber composition havin~ particular utility for fiber ~lass insulation.
Back~round Art Fiber glass, and particularly that used as thermal i~lsulation, is commonly made by the so-called rotary m~thod wherein molten glass is fed onto a rotating spinner having a cylindrical peripheral wall with closely spaced small openings therethrou~h, centrifugal force causing the glass to flow through the openings thereby at least to initiate the formation of the glass fibers.
Conventionally the openings are of a diameter considerably larger than that desired for the final fibers, a reduction in the diameter of the initially formed fiber~ belng attained by attenuation, as by a blast of hot g~8 against the fibers in a direction ~enerally perpendicular to the plane of rotation of the spinner. In another rotary method, that cvvered by U.S. Patent No. 4,058,386, the size of the openin~s and the other parameters of the spinner and method are such that the glass fibers as initially formed are already of extremely small diameter to the end that their attenuation by a hot blast of gas is not mandatory.
This is advantageous in that it eliminates a reguirement for the hi~h ener~y costs involved in providing a continuous hot ~as blast essential to the older method to attain fibers of the small diameter desired for fiber glass insulation.
Both methods reguire that various of the properties of the glass, such as its softening point, its Liguidus temperature and its viscosity at the temperature at which it i8 fed onto the spinner, be within ralatively narrow limits. On the other hand, it iB also important that the glass composition be such as to provide a high ~uality, durable fiber glass insulation product. A lon~ standin~
problem has been that these respective parameters for the processing of the gla~s into fibers and for the characteristics of the manufactured fiber glass product are in conflict. That is, when the ~lass composîtion is formulated in the direction of providing those characteristics needed for efficient fiberizing with a spinner, there i~ compromi~e as regard~ those charPcteristics required for Q good, durable fiber glass product and, vice versa, if the glass i~ formulated in the direction of providing optimum characteristics for the fiber glass product, then there is compromise in the attainment of those characteristics necessary or desirable for rotary fiberiæinG.
Superimposed on all of this i9 the further practical reguirement that the glass composition not be too expensive and hence not contain large amounts, if any, of expensive in~redients. Particularly taking into account this latter consideration, there are only a limited number of raw materials which lend them3elves well as ingredients for the formulation of ~lass for fiber glass insulation, and all or most of them have been used time and a~ain in differing combinations and in differin~ proportions. This would be discouraging but for the further act that even sm~ll differences in the combinations or proportions of ingredients used can result in quite si~nificant differences in properties, and often unpredictably. The solution to the aforesaid problems resides in discovering glass fiber compositions wherein the combination of ingredients and the proportions thereof are such as to provide, at low cost, the vsrious properties desired both for the final product and for its rotary fiberization.
The present invention provides such a glass fib2r composit;on for rotary fiberiz~tion.
Brief Description of the Invention The ~lass fiber composition of the present invention consists essentially of ~PPROXI~ATE
RANGES % BY
WEIGHT
SiO2 53 to 63%
A1203 3 to 7%
B203 5 to 10%
Na20 10 to 15.5%
K20 0 to 2.5 CaO 6 to 12 MgO O to 6~
BaO O ~o 6~;
~1 ~3~
the composition additionally includin~ one or the other or both of, by weight, Li20 up to about 2~, F up to about 1.2'~;
the aggregate amount of the Na20 and Li~O n~t exceeding about 16.4~ by weight, the aggregate amount of the Na20, K20 and Li20 not exceeding about 18~ by weight, the aggregate ~mount of the CaO, MgO and BaO being from about 8% by weight to about 18~ by weight, of which at least about 60% i5 CaO, and the a~gregate ~aount of the Li20 and F being at least about .4% by weight.
The glass has a softening temperature of from 1150`~ to 1230`F and a Liquidus temperature of from 1750`F to 1815'F.
The fiber ~la55 insulation is made by feedit~ the molten glass of the above composition onto a spinner which i~ preferably at a tamperature of from about 2000`F to 7100`F. The visc~si~y and flow characteristics oE the ~lass are compatible with methods of rotary ~iberization which, in their particulars, may vary cot~siderably, but the ~lass is particularly advanta~eous for use in a rotary method as exemplified in the aforementioned U.S. Patent No. 4,058,3B6. The glass
2~ composit;on additionally has the various properties reguired for e~callent, durable fiber glass insulatiotl resistant to deteriorat~on by water, as encountered, for example, in hi~hly hu~id at~spheres in torage facilities.
Detsiled Description and Best Mode for Carryin~ Out the Invention The batching and melting of the glass can be by conventional techniques and in conventional apparatus already in co~mon use and well known to those skilled in the art. Likewise, the preci~e raw ingre~
dients used and the particle sizes thereof can be those conventionally used (thou~h in different combinations and different ratios) to provide the ~lass composition ingredients specifiPd. For example, all of the specified oxide ingredients of the glass composition can be added as 3uch in ~ormulating the batch, and the fluorine can be a~ded a5 a fluoride, generally and preferably calcium fluoride. ~e glass composition is reasonably tolerant of the usual impuritJes resultinG
from the use o~ conYentional low cost raw in~redients. For e~ample, the compositions can and generally wlll include small ~ounts of FQ23' up to appro~imately .1~ or even somewhat hi~her, ~nd S03 in simllar but generally somewhat lesser amounts.
.~,.
Stated ~enerally, the silica, alumina, boric oxide, sodium oxide and calcium oxide of the ~lass composition of the present invention are the basic glass-formin~ ingredients, resultinz in an alkali alkaline earth alumino boro-silicate glass. A cardinal feature of the glass composition is its ratio of these ingredi~nts, which provides one set of desirable properties, in combination with the presence, in the specified amount, of fluorine or lith;um oxide, or both, which corrects for the deficiencies of the ratio ~f ths aforesaid basic ingredients in providing the other set of desirable properties.
!lore specifically~ the ~lass composition has a re]ati~ely low sodium oxide content as compared with various glasses previollsly used for rotary fiberized fiber glass insulation. Since sodium ozide is disadvantageous from the standpoint of fiber durability because it increases the susceptibility of the fiber to water absorption and 5 resulting degradation, the relatively low sodium o~ide ccntenc serves to improve the properties of thte fiber glass insulation as compared with that made of glass having a hi~her sodium oxide content. However, - since sodium oxide is a very active flu~ and hence serves to lower the viscosity of the molten ~lass, the relatively low sodium o~ide content of itself serves to disadvantage as regards those properties desired for the rotsry fiberization. Other of the ingredients c~rrect for this deficiency. Specifically, the composition includes fl~torine in an amount up to 1.2% or lithium o~ide in an amount up to 2%, or a combina-tion of both. Either of these ingredients, or the combination thereof, greatly enhances the fluidity of the molten glnss at flberizing temper-atures thereby providing, in combination with the other in~redients, the properties desired for ease of fiberization. From all standpoints other than cost, a combination of the two is preferred, and because of the cost considerations, where only one is to be ~sed9 ~luorine is preferred. When fluorine is used, particularly without ~he additional inclusion of lithium oxide, it should be present in an ~ntount of at least about .4% by weight, since lesser amounts would no~ sufficiently increase the fluidity of the molten glass, at the ~esired operatin~
temparatures, to adequately compensate for the deficien-cy in this re~ard resultin~ from the relatively low sodium oxide c~ntent. A
fluorine content in excess of about 1.2% would serve no advantage but instead be disadvantageous from a number of standpoints, includin~
~r ~.
environmental control, limited ra~ materials availability, and cost considerations. Where lithium oxide is used, particularly without the additional inclusion of fluorine, the amount of lithium o~ide USf3d should be at least about .4%, sinc4 a lesser amount would not provide as great an increase in the fluidity as is desired to compensate for the loss thereof resulting from the low sodium oxide content. Hore than about 2~ would not only serve to no advantage but to disadvantage, for one reason because of cost and for another because it tends to lessen the resistance of the fiber glass product against deterioration by water. Where a combination of lithium o~ide and fluorine is used, the aggregate a~ount o~ the two should be at least about .4%, and preferably an ag~regate amount of at least about 1.6%, with the lithium oxide content being at least about 1~ and the fluorine content being at least about .6~.
Further, in accordance with the invention, the glass composition can include an alkaline earth metal oxide in addition to the calcium o~ide, one or the other or a combination of ma~,nesium oxide and barium o~ide in an amount, or in an aggregate amount if both are used, not in excess of about 6% by weight. It is preferred that magnesium o~ide or barium oxide or a combination of the two be present in an amount of about 4~ to 6% and the calcium o~ide about 7.5~ to about 9.5%. However, as is clear from the formulations specified above, neither the ma~nesium oxide content nor the barium oxide content should exceed about 6%, and the combined amounts of the calcium oxide and the magnesium o~lde and/or barium o~ide included should be from about 8% to about 18% by wei~ht and preferably about 11.5% to 15.5~, of which at laast about 60~ by wei~ht is calcium oxide. The calcium o~ide, in an amount within the limits specified, enhances fluidity of the molten glass for ease of fiberization and also enhances durability of the fiber glass product. The ma~nesium oxide or barium oxide, or a combination of the two, in amounts within the limits specified, complements the calcium oxide in these respects providing still further improvement. However, if the specified upper limits for the ma~nesium oxide or calcium o~ide, or the upper limit for the combination of them, were exceeded there could be a sienificant increase in the Li~uidus temperature of the composition, thereby detracting from the combination of charaeteristics desired for rotary fiberization. If the calcium ~rjr oxide content, or the co~bination of the total alkaline earth metal oxide present, were below 8% the full advantages as aforesaid would not be gained, and without any compensating advanta~e.
Further, in accorclance with the invention, it is preferred to include as a further in~redien~ potassium oxide in an amount of up to about 2.5~ by weight and, better yet, in an amount to provide a sodiurn o~ide-to-potassium oxide ratio of at least r~bout 7 to 1. The presence of the pota~sium o~ide provides a mixed alkali metal oxide content, i.e., sodium oxide and potassium o~ide, which enhances the fluidity and hence ease of fiberization of the glass without decrease in the properties desired for the fiber glass product. Still somewhat better, in the matter of enhancing the properties of f;berizationt a combination of lithium oxide and potassium oxide is desirable, thereby providing a mixed alkali metal content of sodium oxide, potassium oxide and lithiu~ oxide. However, as is clear from the glass for~ulation specified above, the total alkali metal oxide content should not exceed about 18~ by weight and the total of the sodium o~ide plus any lithium oxide included should not exceed about 16.4~ by weight. What the latter means is that if lithium oxide is included, then the permissible upper limit specified above for the sodium o~ide content should be lowered by an amount equal to the amount of lithium o~ide in excess of .9%. If the combined sodium oxide and lithium oxids content were to exceed about 16.4~, or if the combined content of ~11 three alkali metal oxides were to exceed about 18~, there would 'oe an adYerse effect on the durability characteristics of the fiber glass product, which is not only undesirable but, unnecessary, since the glass composition.s within the specified limits provide ample viscosity ~nd fluidity characteristics to render them excellent for rotary fiberization. ~s is clear from what has been stated previously, even where lithium o~ide is included, it is still preferred to include fluorine in an amount within the limits specified and if, for example, on a cost basis, it becomes a matter of choosing between the two, the best choice is the fluorine.
In the composition specified, the boric oxide enhances the durability of the fiber glass product and also, bein~ a flu~, enhances the viscosity characteristics of the molten glass. These advanta~es are best galned using a boric oxide content of at least ahout 5~. The use of more than about lO~ of boric oxide would pro~ide no advantage adequate to compensate for the resulting increased cost.
The aluminum o~ide content should never be below the speci~ied lower limit of about 3%, since at le~st 3~ is necessary to S prevent devi~rification and to maintain the Li~uidus temperature sufficiently low for rotary fiberization, i.e., lowar than about 1815`F. The specified upper limit for the aluminum oxide content and the specified upper and lower limits for the silica content are those considered necessary ~o impart an optimum combination o~ the desired properties, taking into account the prescribed upper and lower limits for all of the other ingredients.
For attaining the best combination of properties both for the fibar glass product and for its manufacture, and yet at relatively low cost, it is preferred that the glass compositions not include ingredients other than those mentioned, except those which occur in minute amounts, as the above-mentioned or other impurities. However, it is within the purview of the invention in its broadest scope to include small amounts of one or more other ingredients to further enhance one or more of the properties without seriously affecting the others. The disadvanta~e to this is t~e added cost of such other ingredients and generally with the impro~ement attainable not really being necessary or significant enough to justify the added cost -- thi~
bacause the glas~ compositions of the invention, without the inclusion of such additional ingredients, are suitable to provide the combination of tha various desired properties to the e~tent regulred both for the final product and for its manufacture. Examples of other ingredients which could be included are zinc o~ide, titanium o~ide and~or zirconium o~ide, any and all of which, when used in an amount, or ag~re~ate amount of up to about 2~, could serve to further enhance fiber durability. However, all are expensive.
The glass compositions of the present in~ention may be further characterized as having a softening point of from about 1150`F
to 1230`F, a Liguidus temperature of from about 1750 F to lB15 F, a viscosity of from 1200 to 250 poises at temperatures of from 1800`F to 2050`F and a density of about 2.50 to 2.60 g~cm . These and the various other properties are well suited ~or rotary fiberi~ation of the glass In the rotary fiberization, the molten glass as applied to the rotating spinner shou:Ld prQfsr~bly be at a temperature of from about 2000`F to 2100`F. The comparatively low softenin~ point of around 1200`F provides a wide wor~ing ran~e in which the ~lass may be fiberized and attenuated. In all cases the spinner has the gtructure broadly described previously herein and known in the art, the preci~e structure of the spinner and the other parameters 9 such as rotary speed, depending on the precise rotary method used, but exemplified in U.S. Patent No. 4,058,385 identified above.
The following Table I shows a number of specific examples of ~lass compositions in ascordance with the invention. The amounts of each component ~re shown in percent by wei~ht.
TABLE I
Glass Sample Component ~ B C D E F G H
~iO257.0 i8.0 57.8 58.0 57.5 58.0 58.2 57.6 23 5.2 4.4 5.2 5.1 5.0 4.5 3.5 5.2 2 3 6.5 7.6 8.0 8.3 8.7 8.5 8.5 Na2O14.0 14.6 15.2 14.3 14.7 14.3 14.7 14.6 K2O 1.8 0.8 1.1 1.0 1.1 0.8 0.7 1.2 CaO 9.O 8.5 7.9 8.0 8.1 8.5 9.0 8.0 HgO 4.7 4.6 4.3 4.4 4.3 4.7 4.3 4.2 F 0.6 0.6 1.0 0.9 0.9 0.5 0.8 1.1 Li O ---- 1.8 -~
Softenin~
Point1226`F 1152`F1222`F1226`F~216`F1225`F1224`F1211`F
Liquidus Temp.1805`F 1750'F1790`F1800`F1790`F1800`F1760`F *
Water Durability (% Wt.Loss~ 2.1 2.7 1.7 2.3 2.4 ~ * *
Density 2.5712.578 2.558 2.556 2.559 2.561 2.566 2.560 * These te~ts were not performed on these particular samples.
The water degradation test was conducted by boiling a 1 gram sample in 100 ml of water for one hour. The sample is dried, wei~hed and the percent weight loss then computed. The values shown above represent the average of three individual samplings. While each of the specific examples described abo~e uses magnesium oxide, it will be understood that some or all of the magnesium o~ide may be replaced by barium oxide, as discussed previously.
From the data given above with respect to the durability tQStS on the fiber glass insulation made from the specific compositîon~
listed, it will be seen that the durability characteristics of the fiberized glass compositions are e~cellent, and this without the inclusion of expensive in~redients added for the purpose of improving durability.
It will be understood that while the invention has been described narticularly with reference to the preferred embodiments thereof, various chan~es and modifications may be made all within the full and intended scope of the claims which follow.
,~ .
Detsiled Description and Best Mode for Carryin~ Out the Invention The batching and melting of the glass can be by conventional techniques and in conventional apparatus already in co~mon use and well known to those skilled in the art. Likewise, the preci~e raw ingre~
dients used and the particle sizes thereof can be those conventionally used (thou~h in different combinations and different ratios) to provide the ~lass composition ingredients specifiPd. For example, all of the specified oxide ingredients of the glass composition can be added as 3uch in ~ormulating the batch, and the fluorine can be a~ded a5 a fluoride, generally and preferably calcium fluoride. ~e glass composition is reasonably tolerant of the usual impuritJes resultinG
from the use o~ conYentional low cost raw in~redients. For e~ample, the compositions can and generally wlll include small ~ounts of FQ23' up to appro~imately .1~ or even somewhat hi~her, ~nd S03 in simllar but generally somewhat lesser amounts.
.~,.
Stated ~enerally, the silica, alumina, boric oxide, sodium oxide and calcium oxide of the ~lass composition of the present invention are the basic glass-formin~ ingredients, resultinz in an alkali alkaline earth alumino boro-silicate glass. A cardinal feature of the glass composition is its ratio of these ingredi~nts, which provides one set of desirable properties, in combination with the presence, in the specified amount, of fluorine or lith;um oxide, or both, which corrects for the deficiencies of the ratio ~f ths aforesaid basic ingredients in providing the other set of desirable properties.
!lore specifically~ the ~lass composition has a re]ati~ely low sodium oxide content as compared with various glasses previollsly used for rotary fiberized fiber glass insulation. Since sodium ozide is disadvantageous from the standpoint of fiber durability because it increases the susceptibility of the fiber to water absorption and 5 resulting degradation, the relatively low sodium o~ide ccntenc serves to improve the properties of thte fiber glass insulation as compared with that made of glass having a hi~her sodium oxide content. However, - since sodium oxide is a very active flu~ and hence serves to lower the viscosity of the molten ~lass, the relatively low sodium o~ide content of itself serves to disadvantage as regards those properties desired for the rotsry fiberization. Other of the ingredients c~rrect for this deficiency. Specifically, the composition includes fl~torine in an amount up to 1.2% or lithium o~ide in an amount up to 2%, or a combina-tion of both. Either of these ingredients, or the combination thereof, greatly enhances the fluidity of the molten glnss at flberizing temper-atures thereby providing, in combination with the other in~redients, the properties desired for ease of fiberization. From all standpoints other than cost, a combination of the two is preferred, and because of the cost considerations, where only one is to be ~sed9 ~luorine is preferred. When fluorine is used, particularly without ~he additional inclusion of lithium oxide, it should be present in an ~ntount of at least about .4% by weight, since lesser amounts would no~ sufficiently increase the fluidity of the molten glass, at the ~esired operatin~
temparatures, to adequately compensate for the deficien-cy in this re~ard resultin~ from the relatively low sodium oxide c~ntent. A
fluorine content in excess of about 1.2% would serve no advantage but instead be disadvantageous from a number of standpoints, includin~
~r ~.
environmental control, limited ra~ materials availability, and cost considerations. Where lithium oxide is used, particularly without the additional inclusion of fluorine, the amount of lithium o~ide USf3d should be at least about .4%, sinc4 a lesser amount would not provide as great an increase in the fluidity as is desired to compensate for the loss thereof resulting from the low sodium oxide content. Hore than about 2~ would not only serve to no advantage but to disadvantage, for one reason because of cost and for another because it tends to lessen the resistance of the fiber glass product against deterioration by water. Where a combination of lithium o~ide and fluorine is used, the aggregate a~ount o~ the two should be at least about .4%, and preferably an ag~regate amount of at least about 1.6%, with the lithium oxide content being at least about 1~ and the fluorine content being at least about .6~.
Further, in accordance with the invention, the glass composition can include an alkaline earth metal oxide in addition to the calcium o~ide, one or the other or a combination of ma~,nesium oxide and barium o~ide in an amount, or in an aggregate amount if both are used, not in excess of about 6% by weight. It is preferred that magnesium o~ide or barium oxide or a combination of the two be present in an amount of about 4~ to 6% and the calcium o~ide about 7.5~ to about 9.5%. However, as is clear from the formulations specified above, neither the ma~nesium oxide content nor the barium oxide content should exceed about 6%, and the combined amounts of the calcium oxide and the magnesium o~lde and/or barium o~ide included should be from about 8% to about 18% by wei~ht and preferably about 11.5% to 15.5~, of which at laast about 60~ by wei~ht is calcium oxide. The calcium o~ide, in an amount within the limits specified, enhances fluidity of the molten glass for ease of fiberization and also enhances durability of the fiber glass product. The ma~nesium oxide or barium oxide, or a combination of the two, in amounts within the limits specified, complements the calcium oxide in these respects providing still further improvement. However, if the specified upper limits for the ma~nesium oxide or calcium o~ide, or the upper limit for the combination of them, were exceeded there could be a sienificant increase in the Li~uidus temperature of the composition, thereby detracting from the combination of charaeteristics desired for rotary fiberization. If the calcium ~rjr oxide content, or the co~bination of the total alkaline earth metal oxide present, were below 8% the full advantages as aforesaid would not be gained, and without any compensating advanta~e.
Further, in accorclance with the invention, it is preferred to include as a further in~redien~ potassium oxide in an amount of up to about 2.5~ by weight and, better yet, in an amount to provide a sodiurn o~ide-to-potassium oxide ratio of at least r~bout 7 to 1. The presence of the pota~sium o~ide provides a mixed alkali metal oxide content, i.e., sodium oxide and potassium o~ide, which enhances the fluidity and hence ease of fiberization of the glass without decrease in the properties desired for the fiber glass product. Still somewhat better, in the matter of enhancing the properties of f;berizationt a combination of lithium oxide and potassium oxide is desirable, thereby providing a mixed alkali metal content of sodium oxide, potassium oxide and lithiu~ oxide. However, as is clear from the glass for~ulation specified above, the total alkali metal oxide content should not exceed about 18~ by weight and the total of the sodium o~ide plus any lithium oxide included should not exceed about 16.4~ by weight. What the latter means is that if lithium oxide is included, then the permissible upper limit specified above for the sodium o~ide content should be lowered by an amount equal to the amount of lithium o~ide in excess of .9%. If the combined sodium oxide and lithium oxids content were to exceed about 16.4~, or if the combined content of ~11 three alkali metal oxides were to exceed about 18~, there would 'oe an adYerse effect on the durability characteristics of the fiber glass product, which is not only undesirable but, unnecessary, since the glass composition.s within the specified limits provide ample viscosity ~nd fluidity characteristics to render them excellent for rotary fiberization. ~s is clear from what has been stated previously, even where lithium o~ide is included, it is still preferred to include fluorine in an amount within the limits specified and if, for example, on a cost basis, it becomes a matter of choosing between the two, the best choice is the fluorine.
In the composition specified, the boric oxide enhances the durability of the fiber glass product and also, bein~ a flu~, enhances the viscosity characteristics of the molten glass. These advanta~es are best galned using a boric oxide content of at least ahout 5~. The use of more than about lO~ of boric oxide would pro~ide no advantage adequate to compensate for the resulting increased cost.
The aluminum o~ide content should never be below the speci~ied lower limit of about 3%, since at le~st 3~ is necessary to S prevent devi~rification and to maintain the Li~uidus temperature sufficiently low for rotary fiberization, i.e., lowar than about 1815`F. The specified upper limit for the aluminum oxide content and the specified upper and lower limits for the silica content are those considered necessary ~o impart an optimum combination o~ the desired properties, taking into account the prescribed upper and lower limits for all of the other ingredients.
For attaining the best combination of properties both for the fibar glass product and for its manufacture, and yet at relatively low cost, it is preferred that the glass compositions not include ingredients other than those mentioned, except those which occur in minute amounts, as the above-mentioned or other impurities. However, it is within the purview of the invention in its broadest scope to include small amounts of one or more other ingredients to further enhance one or more of the properties without seriously affecting the others. The disadvanta~e to this is t~e added cost of such other ingredients and generally with the impro~ement attainable not really being necessary or significant enough to justify the added cost -- thi~
bacause the glas~ compositions of the invention, without the inclusion of such additional ingredients, are suitable to provide the combination of tha various desired properties to the e~tent regulred both for the final product and for its manufacture. Examples of other ingredients which could be included are zinc o~ide, titanium o~ide and~or zirconium o~ide, any and all of which, when used in an amount, or ag~re~ate amount of up to about 2~, could serve to further enhance fiber durability. However, all are expensive.
The glass compositions of the present in~ention may be further characterized as having a softening point of from about 1150`F
to 1230`F, a Liguidus temperature of from about 1750 F to lB15 F, a viscosity of from 1200 to 250 poises at temperatures of from 1800`F to 2050`F and a density of about 2.50 to 2.60 g~cm . These and the various other properties are well suited ~or rotary fiberi~ation of the glass In the rotary fiberization, the molten glass as applied to the rotating spinner shou:Ld prQfsr~bly be at a temperature of from about 2000`F to 2100`F. The comparatively low softenin~ point of around 1200`F provides a wide wor~ing ran~e in which the ~lass may be fiberized and attenuated. In all cases the spinner has the gtructure broadly described previously herein and known in the art, the preci~e structure of the spinner and the other parameters 9 such as rotary speed, depending on the precise rotary method used, but exemplified in U.S. Patent No. 4,058,385 identified above.
The following Table I shows a number of specific examples of ~lass compositions in ascordance with the invention. The amounts of each component ~re shown in percent by wei~ht.
TABLE I
Glass Sample Component ~ B C D E F G H
~iO257.0 i8.0 57.8 58.0 57.5 58.0 58.2 57.6 23 5.2 4.4 5.2 5.1 5.0 4.5 3.5 5.2 2 3 6.5 7.6 8.0 8.3 8.7 8.5 8.5 Na2O14.0 14.6 15.2 14.3 14.7 14.3 14.7 14.6 K2O 1.8 0.8 1.1 1.0 1.1 0.8 0.7 1.2 CaO 9.O 8.5 7.9 8.0 8.1 8.5 9.0 8.0 HgO 4.7 4.6 4.3 4.4 4.3 4.7 4.3 4.2 F 0.6 0.6 1.0 0.9 0.9 0.5 0.8 1.1 Li O ---- 1.8 -~
Softenin~
Point1226`F 1152`F1222`F1226`F~216`F1225`F1224`F1211`F
Liquidus Temp.1805`F 1750'F1790`F1800`F1790`F1800`F1760`F *
Water Durability (% Wt.Loss~ 2.1 2.7 1.7 2.3 2.4 ~ * *
Density 2.5712.578 2.558 2.556 2.559 2.561 2.566 2.560 * These te~ts were not performed on these particular samples.
The water degradation test was conducted by boiling a 1 gram sample in 100 ml of water for one hour. The sample is dried, wei~hed and the percent weight loss then computed. The values shown above represent the average of three individual samplings. While each of the specific examples described abo~e uses magnesium oxide, it will be understood that some or all of the magnesium o~ide may be replaced by barium oxide, as discussed previously.
From the data given above with respect to the durability tQStS on the fiber glass insulation made from the specific compositîon~
listed, it will be seen that the durability characteristics of the fiberized glass compositions are e~cellent, and this without the inclusion of expensive in~redients added for the purpose of improving durability.
It will be understood that while the invention has been described narticularly with reference to the preferred embodiments thereof, various chan~es and modifications may be made all within the full and intended scope of the claims which follow.
,~ .
Claims (9)
1. Fiber glass having a composition consisting essentially of, by weight:
SiO2 53 to 63%
A12O3 3 to 7%
B2O3 5 to 10%
Na2O 10 to 15.5%
K2O 0 to 2.5%
CaO 6 to 12%
MgO 0 to 6%
BaO 0 to 6%;
the composition additionally including one or the other or both of, by weight:
Li2O up to about 2%
F up to about 1.2%;
the aggregate amount of the Na2O and Li2O not exceeding about 16.4% by weight, the aggregate amount of the Na2O, K2O and Li2O not exceeding about 18% by weight, and the aggregate amount of the CaO, MgO and BaO being from about 8 to about 18% by weight, of which at least about 60% is CaO, and the aggregate amount of the Li2O
and F being at least about .4%.
SiO2 53 to 63%
A12O3 3 to 7%
B2O3 5 to 10%
Na2O 10 to 15.5%
K2O 0 to 2.5%
CaO 6 to 12%
MgO 0 to 6%
BaO 0 to 6%;
the composition additionally including one or the other or both of, by weight:
Li2O up to about 2%
F up to about 1.2%;
the aggregate amount of the Na2O and Li2O not exceeding about 16.4% by weight, the aggregate amount of the Na2O, K2O and Li2O not exceeding about 18% by weight, and the aggregate amount of the CaO, MgO and BaO being from about 8 to about 18% by weight, of which at least about 60% is CaO, and the aggregate amount of the Li2O
and F being at least about .4%.
2. A fiber glass composition as set forth in Claim 1 wherein fluorine is present in an amount of at least .4%.
3. A fiber glass composition as set forth in Claim 1 wherein lithium oxide is present in an amount of at least 1%.
4. A fiber glass composition as set forth in Claim 1 wherein fluorine is present in an amount of at least .6% and lithium oxide is present in an amount of at least 1%.
5. A fiber glass composition as set forth in Claim 1, 2 or 3 wherein potassium oxide is present in an amount of at least 1%.
6. A fiber glass composition as set forth in Claim 1, 2 or 3 wherein magnesium oxide or barium oxide or a combination of the two is present in an amount of about 4%.
7. A fiber glass composition as set forth in Claim 1 consisting essentially of, by weight:
SiO2 57.0%
Al2O3 5.2%
B2O3 7.7%
Na2O 14.0%
K2O 1.8%
CaO 9.0%
MgO 4.7%
F .6%
SiO2 57.0%
Al2O3 5.2%
B2O3 7.7%
Na2O 14.0%
K2O 1.8%
CaO 9.0%
MgO 4.7%
F .6%
8. A fiber glass composition as set forth in Claim 1 consisting essentially of, by weight:
SiO2 58.0%
Al2O3 4.4%
B2O3 6.5%
Na2O 14.6%
K2O .8%
CaO 8.5%
MgO 4.7%
F .6%
Li O 1.8%
SiO2 58.0%
Al2O3 4.4%
B2O3 6.5%
Na2O 14.6%
K2O .8%
CaO 8.5%
MgO 4.7%
F .6%
Li O 1.8%
9. A fiber glass composition as set forth in Claim 1 consisting essentially of, by weight:
SiO2 57.8%
Al2O3 5.2%
B2O3 7.6%
Na2O 15.2%
K2O 1.1%
CaO 7.9%
MgO 4.3%
F 1.0%
SiO2 57.8%
Al2O3 5.2%
B2O3 7.6%
Na2O 15.2%
K2O 1.1%
CaO 7.9%
MgO 4.3%
F 1.0%
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US34989482A | 1982-02-18 | 1982-02-18 | |
| US06/349,894 | 1982-02-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1193290A true CA1193290A (en) | 1985-09-10 |
Family
ID=23374418
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000421883A Expired CA1193290A (en) | 1982-02-18 | 1983-02-17 | Fiber glass composition |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1193290A (en) |
| ES (1) | ES519862A0 (en) |
| FR (1) | FR2521547B1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5401693A (en) * | 1992-09-18 | 1995-03-28 | Schuller International, Inc. | Glass fiber composition with improved biosolubility |
| US8198505B2 (en) | 2006-07-12 | 2012-06-12 | The Procter & Gamble Company | Disposable absorbent articles comprising non-biopersistent inorganic vitreous microfibers |
| CN103274603A (en) * | 2013-05-31 | 2013-09-04 | 重庆再升科技股份有限公司 | Novel glass fiber, glass fiber-based vacuum heat-insulating plate core material, and preparation method of core material |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2552075B1 (en) * | 1983-09-19 | 1986-08-14 | Saint Gobain Isover | GLASS FIBERS AND COMPOSITION SUITABLE FOR THEIR MANUFACTURE |
| DE4421120A1 (en) * | 1994-06-19 | 1995-12-21 | Gruenzweig & Hartmann | Mineral fibre compsn. |
| DE19731607B4 (en) * | 1997-07-23 | 2004-09-09 | Johns Manville Europe Gmbh | Glasses for making glass fibers |
| US6034014A (en) * | 1997-08-04 | 2000-03-07 | Owens Corning Fiberglas Technology, Inc. | Glass fiber composition |
| FR2781788B1 (en) * | 1998-08-03 | 2001-08-10 | Saint Gobain Isover | COMPOSITION OF MINERAL WOOL |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE552902A (en) * | 1955-11-25 | |||
| FR1355739A (en) * | 1963-02-07 | 1964-03-20 | Saint Gobain | Glass compositions |
| FR1429387A (en) * | 1965-01-14 | 1966-02-18 | Saint Gobain | Glass compositions |
| BE805784A (en) * | 1972-10-10 | 1974-04-08 | Johns Manville | GLASS COMPOSITION |
-
1983
- 1983-02-17 ES ES519862A patent/ES519862A0/en active Granted
- 1983-02-17 FR FR8302588A patent/FR2521547B1/en not_active Expired
- 1983-02-17 CA CA000421883A patent/CA1193290A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5401693A (en) * | 1992-09-18 | 1995-03-28 | Schuller International, Inc. | Glass fiber composition with improved biosolubility |
| US8198505B2 (en) | 2006-07-12 | 2012-06-12 | The Procter & Gamble Company | Disposable absorbent articles comprising non-biopersistent inorganic vitreous microfibers |
| CN103274603A (en) * | 2013-05-31 | 2013-09-04 | 重庆再升科技股份有限公司 | Novel glass fiber, glass fiber-based vacuum heat-insulating plate core material, and preparation method of core material |
Also Published As
| Publication number | Publication date |
|---|---|
| ES8403429A1 (en) | 1984-03-16 |
| ES519862A0 (en) | 1984-03-16 |
| FR2521547A1 (en) | 1983-08-19 |
| FR2521547B1 (en) | 1986-04-11 |
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