High-modulus glass fiber composition, glass fiber and composite material therefrom

Abstract

The present invention provides a high-modulus glass fiber composition, a glass fiber and a composite material therefrom. The glass fiber composition comprises the following components expressed as percentage by weight: 55-64% SiO.sub.2, 13-24% Al.sub.2O.sub.3, 0.1-6% Y.sub.2O.sub.3, 3.4-10.9% CaO, 8-14% MgO, lower than 22% CaO+MgO+SrO, lower than 2% Li.sub.2O+Na.sub.2O+K.sub.2O, lower than 2% TiO.sub.2, lower than 1.5% Fe.sub.2O.sub.3, 0-1.2% La.sub.2O.sub.3, wherein the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.26. Said composition can significantly increase the glass elastic modulus, effectively inhibit the crystallization tendency of glass, decrease the liquidus temperature, secure a desirable temperature range (T) for fiber formation and enhance the fining of molten glass, thus making it particularly suitable for production of high-modulus glass fiber with refractory-lined furnaces.

Claims

1. A high-modulus glass fiber composition, comprising the following components expressed as percentage by weight: TABLE-US-00038 SiO.sub.2 55-64% Al.sub.2O.sub.3 16.7-24% Y.sub.2O.sub.3 0.1-2.4% CaO 3.4-10.9% MgO 9.4-14% CaO + MgO + SrO <22% Li.sub.2O + Na.sub.2O + K.sub.2O <2% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.26.

2. The high-modulus glass fiber composition according to claim 1, wherein the content range of Li.sub.2O by weight is 0.1-1.5%.

3. The high-modulus glass fiber composition according to claim 1, wherein the content range of SrO by weight is 0.1-2.5%.

4. The high-modulus glass fiber composition according to claim 1, wherein the content range of CaO by weight is 6-10.3%.

5. The high-modulus glass fiber composition according to claim 1, wherein the content range of MgO by weight is 9.4-13%.

6. The high-modulus glass fiber composition according to claim 1, wherein the content range of La.sub.2O.sub.3 by weight is 0.1-1%.

7. The high-modulus glass fiber composition according to claim 1, comprising CeO.sub.2 with the weight percentage of 0-1%.

8. The high-modulus glass fiber composition according to claim 1, wherein the range of the weight percentage ratio C2=MgO/(CaO+SrO) is 0.8-2.1.

9. The high-modulus glass fiber composition according to claim 8, wherein the content range of Y.sub.2O.sub.3 by weight is 0.5-2.4%.

10. The high-modulus glass fiber composition according to claim 8, wherein the content range of Y.sub.2O.sub.3 by weight is 1.5-2.4%.

11. A glass fiber, characterized by, being produced from the glass fiber compositions according to claim 1.

12. The glass fiber according to claim 11, characterized by, having the range of the elastic modulus 90-103 GPa.

13. A composite material, characterized by, incorporating the glass fiber according to claim 11.

14. The high-modulus glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00039 SiO.sub.2 56-60.4% Al.sub.2O.sub.3 16.7-24% Y.sub.2O.sub.3 0.1-2.4% CaO 3.4-10.9% MgO 9.4-14% CaO + MgO + SrO <22% SrO <3% Li.sub.2O + Na.sub.2O + K.sub.2O <2% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.26.

15. The high-modulus glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00040 SiO.sub.2 56-60.4% Al.sub.2O.sub.3 16.7-24% Y.sub.2O.sub.3 0.5-2.4% CaO 3.4-10.9% MgO 9.4-14% CaO + MgO + SrO <22% SrO <3% Li.sub.2O 0.1-1.5% Li.sub.2O + Na.sub.2O + K.sub.2O <2% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.26, and the weight percentage ratio C2=MgO/(CaO+SrO) is 0.8-2.1.

16. The high-modulus glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00041 SiO.sub.2 56-60.4% Al.sub.2O.sub.3 16.7-24% Y.sub.2O.sub.3 0.5-2.4% CaO 3.4-10.9% MgO 9.4-14% CaO + MgO + SrO <22% SrO <3% Li.sub.2O 0.1-1.5% Li.sub.2O + Na.sub.2O + K.sub.2O <2% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.28, and the weight percentage ratio C2=MgO/(CaO+SrO) is 0.8-2.1.

17. The high-modulus glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00042 SiO.sub.2 57-60.4% Al.sub.2O.sub.3 16.7-24% Y.sub.2O.sub.3 0.5-2.4% CaO 5-10.6% MgO 9.4-14% CaO + MgO + SrO <21% SrO <3% Li.sub.2O 0.1-1% Li.sub.2O + Na.sub.2O + K.sub.2O <2% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.28, and the weight percentage ratio C2=MgO/(CaO+SrO) is 0.8-2.1.

18. The high-modulus glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00043 SiO.sub.2 57-60.4% Al.sub.2O.sub.3 16.7-23% Y.sub.2O.sub.3 1.5-2.4% CaO 6-10.3% MgO 9.4-13% CaO + MgO + SrO <21% SrO <3% Li.sub.2O 0.1-1% Li.sub.2O + Na.sub.2O + K.sub.2O <2% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.29, and the weight percentage ratio C2=MgO/(CaO+SrO) is 0.9-1.8.

19. The high-modulus glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00044 SiO.sub.2 57-60.4% Al.sub.2O.sub.3 16.7-23% Y.sub.2O.sub.3 1.5-2.4% CaO 6-10.3% MgO 9.4-13% CaO + MgO + SrO <21% SrO <3% Li.sub.2O 0.1-1% Li.sub.2O + Na.sub.2O + K.sub.2O <2% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.29, and the weight percentage ratio C2=MgO/(CaO+SrO) is 0.9-1.7.

20. The high-modulus glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00045 SiO.sub.2 55-64% Al.sub.2O.sub.3 greater than 19% and not greater than 21% Y.sub.2O.sub.3 0.1-2.4% CaO 3.4-10.9% MgO 9.4-10.5% CaO + MgO + SrO <22% Li.sub.2O + Na.sub.2O + K.sub.2O 1% TiO.sub.2 <2% Fe.sub.2O.sub.3 <1.5% La.sub.2O.sub.3 0-1.2% wherein, the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.26.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) In order to better clarify the purposes, technical solutions and advantages of the examples of the present invention, the technical solutions in the examples of the present invention are clearly and completely described below. Obviously, the examples described herein are just part of the examples of the present invention and are not all the examples. All other exemplary embodiments obtained by one skilled in the art on the basis of the examples in the present invention without performing creative work shall all fall into the scope of protection of the present invention. What needs to be made clear is that, as long as there is no conflict, the examples and the features of examples in the present application can be arbitrarily combined with each other.

(2) The basic concept of the present invention is that the components of the glass fiber composition expressed as percentage by weight are: 55-64% SiO.sub.2, 13-24% Al.sub.2O.sub.3, 0.1-6% Y.sub.2O.sub.3, 3.4-10.9% CaO, 8-14% MgO, lower than 22% CaO+MgO+SrO, lower than 2% Li.sub.2O+Na.sub.2O+K.sub.2O, lower than 2% TiO.sub.2, lower than 1.5% Fe.sub.2O.sub.3, 0-1.2% La.sub.2O.sub.3, wherein the range of the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/(Y.sub.2O.sub.3+La.sub.2O.sub.3) is greater than 0.26. Said composition can significantly increase the glass elastic modulus, effectively inhibit the crystallization tendency of glass, decrease the liquidus temperature, secure a desirable temperature range (T) for fiber formation and enhance the fining of molten glass, thus making it particularly suitable for high modulus glass fiber production with refractory-lined furnaces.

(3) The specific content values of SiO.sub.2, Al.sub.2O.sub.3, Y.sub.2O.sub.3, CaO, MgO, Li.sub.2O, Na.sub.2O, K.sub.2O, Fe.sub.2O.sub.3, TiO.sub.2, SrO and La.sub.2O.sub.3 in the glass fiber composition of the present invention are selected to be used in the examples, and comparisons with S glass, traditional R glass and improved R glass are made in terms of the following six property parameters,

(4) (1) Forming temperature, the temperature at which the glass melt has a viscosity of 10.sup.3 poise.

(5) (2) Liquidus temperature, the temperature at which the crystal nucleuses begin to form when the glass melt cools offi.e., the upper limit temperature for glass crystallization.

(6) (3) T value, which is the difference between the forming temperature and the liquidus temperature and indicates the temperature range at which fiber drawing can be performed.

(7) (4) Peak crystallization temperature, the temperature which corresponds to the strongest peak of glass crystallization during the DTA testing. Generally, the higher this temperature is, the more energy is needed by crystal nucleuses to grow and the lower the glass crystallization tendency is.

(8) (5) Elastic modulus, the linear elastic modulus defining the ability of glass to resist elastic deformation, which is to be measured as per ASTM2343.

(9) (6) Amount of bubbles, to be determined in a procedure set out as follows: Use specific moulds to compress the glass batch materials in each example into samples of same dimension, which will then be placed on the sample platform of a high temperature microscope. Heat the samples according to standard procedures up to the pre-set spatial temperature 1500 C. and then directly cool them off with the cooling hearth of the microscope to the ambient temperature without heat preservation. Finally, each of the glass samples is examined under a polarizing microscope to determine the amount of bubbles in the samples. A bubble is identified according to a specific amplification of the microscope.

(10) The aforementioned six parameters and the methods of measuring them are well-known to one skilled in the art. Therefore, these parameters can be effectively used to explain the properties of the glass fiber composition of the present invention.

(11) The specific procedures for the experiments are as follows: Each component can be acquired from the appropriate raw materials. Mix the raw materials in the appropriate proportions so that each component reaches the final expected weight percentage. The mixed batch melts and the molten glass refines. Then the molten glass is drawn out through the tips of the bushings, thereby forming the glass fiber. The glass fiber is attenuated onto the rotary collet of a winder to form cakes or packages. Of course, conventional methods can be used to deep process these glass fibers to meet the expected requirements.

(12) The exemplary embodiments of the glass fiber composition according to the present invention are given below.

EXAMPLE 1

(13) TABLE-US-00023 SiO.sub.2 59.5% Al.sub.2O.sub.3 16.7% CaO 8.9% MgO 9.5% Y.sub.2O.sub.3 1.8% Na.sub.2O 0.23% K.sub.2O 0.36% Li.sub.2O 0.75% Fe.sub.2O.sub.3 0.44% TiO.sub.2 0.43% SrO 1.0%

(14) In addition, the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/Y.sub.2O.sub.3 is 0.74, and the weight percentage ratio C2=MgO/(CaO+SrO) is 0.96.

(15) In Example 1, the measured values of the six parameters are respectively:

(16) TABLE-US-00024 Forming temperature 1298 C. Liquidus temperature 1205 C. T 93 C. Peak crystallization temperature 1023 C. Elastic modulus 93.9 GPa Amount of bubbles 11

EXAMPLE 2

(17) TABLE-US-00025 SiO.sub.2 59.3% Al.sub.2O.sub.3 17.0% CaO 8.2% MgO 9.7% Y.sub.2O.sub.3 3.3% Na.sub.2O 0.22% K.sub.2O 0.37% Li.sub.2O 0.75% Fe.sub.2O.sub.3 0.44% TiO.sub.2 0.44%

(18) In addition, the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/Y.sub.2O.sub.3 is 0.41, and the weight percentage ratio C2=MgO/(CaO+SrO) is 1.18.

(19) In Example 2, the measured values of the six parameters are respectively:

(20) TABLE-US-00026 Forming temperature 1300 C. Liquidus temperature 1206 C. T 94 C. Peak crystallization temperature 1024 C. Elastic modulus 95.6 GPa Amount of bubbles 8

EXAMPLE 3

(21) TABLE-US-00027 SiO.sub.2 58.2% Al.sub.2O.sub.3 19.2% CaO 6.7% MgO 10% Y.sub.2O.sub.3 3.4% Na.sub.2O 0.19% K.sub.2O 0.23% Li.sub.2O 0.55% Fe.sub.2O.sub.3 0.44% TiO.sub.2 0.82%

(22) In addition, the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/Y.sub.2O.sub.3 is 0.29, and the weight percentage ratio C2=MgO/(CaO+SrO) is 1.49.

(23) In Example 3, the measured values of the six parameters are respectively:

(24) TABLE-US-00028 Forming temperature 1305 C. Liquidus temperature 1200 C. T 105 C. Peak crystallization temperature 1024 C. Elastic modulus 97.0 GPa Amount of bubbles 11

EXAMPLE 4

(25) TABLE-US-00029 SiO.sub.2 58.8% Al.sub.2O.sub.3 17.4% CaO 5.8% MgO 10.4% Y.sub.2O.sub.3 5.0% Na.sub.2O 0.29% K.sub.2O 0.49% Li.sub.2O 0.75% Fe.sub.2O.sub.3 0.43% TiO.sub.2 0.40%

(26) In addition, the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/Y.sub.2O.sub.3 is 0.31, and the weight percentage ratio C2=MgO/(CaO+SrO) is 1.79.

(27) In Example 4, the measured values of the six parameters are respectively:

(28) TABLE-US-00030 Forming temperature 1303 C. Liquidus temperature 1213 C. T 90 C. Peak crystallization temperature 1029 C. Elastic modulus 100.3 GPa Amount of bubbles 9

EXAMPLE 5

(29) TABLE-US-00031 SiO.sub.2 59.3% Al.sub.2O.sub.3 17.1% CaO 7.6% MgO 10.4% Y.sub.2O.sub.3 3.1% Na.sub.2O 0.21% K.sub.2O 0.34% Li.sub.2O 0.45% Fe.sub.2O.sub.3 0.44% TiO.sub.2 0.43% SrO 0.3%

(30) In addition, the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/Y.sub.2O.sub.3 is 0.32, and the weight percentage ratio C2=MgO/(CaO+SrO) is 1.37.

(31) In Example 5, the measured values of the six parameters are respectively:

(32) TABLE-US-00032 Forming temperature 1296 C. Liquidus temperature 1206 C. T 90 C. Peak crystallization temperature 1021 C. Elastic modulus 94.1 GPa Amount of bubbles 10

EXAMPLE 6

(33) TABLE-US-00033 SiO.sub.2 59.3% Al.sub.2O.sub.3 16.3% CaO 6.1% MgO 12.2% Y.sub.2O.sub.3 3.4% Na.sub.2O 0.23% K.sub.2O 0.46% Li.sub.2O 0.50% Fe.sub.2O.sub.3 0.44% TiO.sub.2 0.82%

(34) In addition, the weight percentage ratio C1=(Li.sub.2O+Na.sub.2O+K.sub.2O)/Y.sub.2O.sub.3 is 0.35, and the weight percentage ratio C2=MgO/(CaO+SrO) is 2.

(35) In Example 6, the measured values of the six parameters are respectively:

(36) TABLE-US-00034 Forming temperature 1300 C. Liquidus temperature 1220 C. T 80 C. Peak crystallization temperature 1020 C. Elastic modulus 97.1 GPa Amount of bubbles 10

(37) Comparisons of the property parameters of the aforementioned examples and other examples of the glass fiber composition of the present invention with those of traditional E glass, traditional R glass and improved R glass are further made below by way of tables, wherein the component contents of the glass fiber composition are expressed as weight percentage. What needs to be made clear is that the total amount of the components in the examples is slightly less than 100%, and it should be understood that the remaining amount is trace impurities or a small amount of components which cannot be analyzed.

(38) TABLE-US-00035 TABLE 1A A1 A2 A3 A4 A5 A6 A7 Component SiO.sub.2 59.4 59.3 59.5 59.4 60.1 58.2 59.3 Al.sub.2O.sub.3 16.9 17.1 16.6 16.7 17.0 19.2 16.3 CaO 7.8 7.6 7.3 9.7 10.2 6.7 6.1 MgO 9.6 10.4 10.0 9.4 9.8 10.0 12.2 Y.sub.2O.sub.3 3.1 3.1 3.1 2.4 0.5 3.4 3.4 Na.sub.2O 0.21 0.21 0.21 0.23 0.21 0.19 0.23 K.sub.2O 0.42 0.34 0.51 0.38 0.41 0.23 0.46 Li.sub.2O 0.71 0.45 0.60 0.70 0.65 0.55 0.50 Fe.sub.2O.sub.3 0.44 0.44 0.44 0.44 0.44 0.44 0.44 TiO.sub.2 0.43 0.43 0.37 0.42 0.44 0.82 0.82 SrO 0.7 0.3 1.1 Ratio C1 0.43 0.32 0.43 0.55 2.54 0.29 0.35 C2 1.13 1.37 1.19 0.97 0.96 1.49 2 Parameter Forming 1294 1296 1295 1298 1300 1305 1300 temperature/ C. Liquidus 1202 1206 1199 1200 1208 1200 1220 temperature/ C. T/ C. 92 90 96 98 92 105 80 Peak 1023 1021 1025 1022 1018 1024 1020 crystallization temperature/ C. Elastic 95.0 94.1 95.8 93.3 90.9 97.0 97.1 modulus/GPa Amount of 9 10 11 10 12 11 10 bubbles/pcs

(39) TABLE-US-00036 TABLE 1B A8 A9 A10 A11 A12 A13 A14 Component SiO.sub.2 59.1 59.1 59.3 59.4 59.1 60.4 61.0 Al.sub.2O.sub.3 16.9 17.0 16.8 16.7 16.8 16.7 16.2 CaO 6.8 6.9 10.0 9.0 9.9 9.2 8.5 MgO 10.8 10.8 9.8 9.4 9.3 9.7 9.7 Y.sub.2O.sub.3 3.7 3.7 2.0 3.0 3.0 0.5 0.9 Na.sub.2O 0.21 0.23 0.21 0.32 0.21 0.21 0.21 K.sub.2O 0.42 0.36 0.32 0.58 0.39 0.43 0.43 Li.sub.2O 0.61 0.41 0.37 0.45 0.20 0.75 0.75 Fe.sub.2O.sub.3 0.44 0.44 0.44 0.44 0.44 0.44 0.44 TiO.sub.2 0.43 0.43 0.42 0.42 0.42 0.44 0.42 SrO 0.3 0.3 La.sub.2O.sub.3 1 1.2 Ratio C1 0.34 0.27 0.45 0.45 0.27 0.93 0.66 C2 1.52 1.50 0.98 1.04 0.94 1.05 1.14 Parameter Forming 1295 1297 1292 1297 1296 1296 1302 temperature/ C. Liquidus 1206 1212 1204 1202 1206 1205 1203 temperature/ C. T/ C. 89 85 88 95 90 91 100 Peak 1028 1026 1020 1023 1021 1020 1023 crystallization temperature/ C. Elastic 97.1 95.7 92.9 94.3 93.5 91.2 92.1 modulus/GPa Amount of 8 9 10 9 10 6 5 bubbles/pcs

(40) TABLE-US-00037 TABLE 1C Traditional Improved A15 A16 A17 A18 S glass R glass R glass Component SiO.sub.2 58.8 59.7 59.5 59.3 65 60 60.75 Al.sub.2O.sub.3 17.4 16.8 16.7 17.0 25 25 15.80 CaO 5.8 10.1 8.9 8.2 9 13.90 MgO 10.4 9.3 9.5 9.7 10 6 7.90 Y.sub.2O.sub.3 5.0 1.6 1.8 3.3 Na.sub.2O 0.29 0.22 0.23 0.22 trace trace 0.73 amount amount K.sub.2O 0.49 0.38 0.36 0.37 trace trace amount amount Li.sub.2O 0.75 0.75 0.75 0.75 0.48 Fe.sub.2O.sub.3 0.43 0.44 0.44 0.44 trace trace 0.18 amount amount TiO.sub.2 0.40 0.43 0.43 0.44 trace trace 0.12 amount amount SrO 1.0 Ratio C1 0.31 0.84 0.74 0.41 C2 1.79 0.92 0.96 1.18 0.67 0.57 Parameter Forming 1303 1299 1298 1300 1571 1430 1278 temperature/ C. Liquidus 1213 1210 1205 1206 1470 1350 1210 temperature/ C. T/ C. 90 89 93 94 101 80 68 Peak 1029 1021 1023 1024 1010 1016 crystallization temperature/ C. Elastic 100.3 93.0 93.9 95.6 89 88 87 modulus/GPa Amount of 9 10 11 8 40 30 25 bubbles/pcs

(41) It can be seen from the values in the above tables that, compared with the S glass and traditional R glass, the glass fiber composition of the present invention has the following advantages: (1) much higher elastic modulus; (2) much lower liquidus temperature, which helps to reduce crystallization risk and increase the fiber drawing efficiency; relatively high peak crystallization temperature, which indicates that more energy is needed for the formation and growth of crystal nucleuses during the crystallization process of glass, i.e. the crystallization risk of the glass of the present invention is smaller under the same conditions; (3) smaller amount of bubbles, which indicates a better refining of molten glass.

(42) Both S glass and traditional R glass cannot enable the achievement of large-scale production with refractory-lined furnaces and, with respect to improved R glass, part of the glass properties is compromised to reduce the liquidus temperature and forming temperature, so that the production difficulty is decreased and the production with refractory-lined furnaces could be achieved. By contrast, the glass fiber composition of the present invention not only has a sufficiently low liquidus temperature and forming temperature which permit the production with refractory-lined furnaces, but also significantly increases the glass modulus, thereby resolving the technical bottleneck that the modulus of S glass fiber and R glass fiber cannot be improved with the growth of production scale.

(43) The glass fiber composition according to the present invention can be used for making glass fibers having the aforementioned excellent properties.

(44) The glass fiber composition according to the present invention in combination with one or more organic and/or inorganic materials can be used for preparing composite materials having excellent performances, such as glass fiber reinforced base materials.

(45) Finally, what should be made clear is that, in this text, the terms contain, comprise or any other variants are intended to mean nonexclusively include so that any process, method, article or equipment that contains a series of factors shall include not only such factors, but also include other factors that are not explicitly listed, or also include intrinsic factors of such process, method, object or equipment. Without more limitations, factors defined by such phrase as contain a . . . do not rule out that there are other same factors in the process, method, article or equipment which include said factors.

(46) The above examples are provided only for the purpose of illustrating instead of limiting the technical solutions of the present invention. Although the present invention is described in details by way of aforementioned examples, one skilled in the art shall understand that modifications can also be made to the technical solutions embodied by all the aforementioned examples or equivalent replacement can be made to some of the technical features. However, such modifications or replacements will not cause the resulting technical solutions to substantially deviate from the spirits and ranges of the technical solutions respectively embodied by the examples of the present invention.

INDUSTRIAL APPLICABILITY OF THE INVENTION

(47) The glass fiber composition of the present invention not only has a sufficiently low liquidus temperature and forming temperature which enable the production with refractory-lined furnaces, but also significantly increases the glass modulus, thereby resolving the technical bottleneck that the modulus of S glass fiber and R glass fiber cannot be improved with the enhanced production scale. Compared with the current main-stream high-modulus glasses, the glass fiber composition of the present invention has made a breakthrough in terms of elastic modulus, crystallization performance and fining performance of the glass, with significantly improved modulus, remarkably reduced crystallization risk and relatively small amount of bubbles under the same conditions. Thus, the overall technical solution of the present invention enables an easy achievement of large-scale production with refractory-lined furnaces.