GLASS FIBER COMPOSITION, GLASS FIBER AND COMPOSITE MATERIAL THEREFROM

Abstract

The present invention provides a glass fiber composition, glass fiber and composite material therefrom. The glass fiber composition comprises the following components expressed as percentage by weight: 56-64% SiO.sub.2, 12-18% Al.sub.2O.sub.3, 0.1-1% Na.sub.2O, 0.1-1% K.sub.2O, 0.1-1% Fe.sub.2O.sub.3, 0.05-1% Li.sub.2O+Bi.sub.2O.sub.3, 19-25% CaO+MgO+SrO, 0.1-1.5% TiO.sub.2 and 0-1% CeO.sub.2, wherein a weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and a weight percentage ratio C2=(MgO+SrO)/CaO is 0.4-1, and a weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.7. Said composition reduces the amount of bubbles, viscosity and crystallization risk of the glass, thereby making it more suitable for large-scale production with refractory-lined furnaces.

Claims

1. A glass fiber composition, comprising the following components expressed as percentage by weight: TABLE-US-00016 SiO.sub.2 56-64% Al.sub.2O.sub.3 12-18% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.05-1% CaO + MgO + SrO 19-25% TiO.sub.2 0.1-1.5% CeO.sub.2 0-1% wherein, a weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and a weight percentage ratio C2=(MgO+SrO)/CaO is 0.4-1, and a weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.7.

2. The glass fiber composition according to claim 1, wherein the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12.

3. The glass fiber composition according to claim 1, wherein the weight percentage ratio C2 =(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3 =MgO/(MgO+SrO) is greater than 0.85.

4. The glass fiber composition according to claim 1, wherein the content range of CaO by weight percentage is greater than 9.5% and less than 12%.

5. The glass fiber composition according to claim 1, wherein the content range of Bi2O3 by weight percentage is 0.02-0.35%.

6. The glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00017 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.1-0.9% CaO + MgO + SrO 20-24% TiO.sub.2 0.1-1.5% SrO 0-2% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and the weight percentage ratio C2 =(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

7. The glass fiber composition according to claim 1, wherein the content range of SrO by weight percentage is 0.02-1.5%.

8. The glass fiber composition according to claim 1, comprising the following components expressed as percentage by weight: TABLE-US-00018 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.2-0.8% CaO + MgO + SrO 21-23.5% TiO.sub.2 0.1-1.5% SrO 0.02-1.5% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

9. A glass fiber, being produced from the glass fiber compositions described in claim 1.

10. A composite material, incorporating the glass fiber described in claim 9.

11. The glass fiber according to claim 9, wherein the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12,and wherein the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

12. The glass fiber according to claim 9, wherein the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12,and wherein the content range of CaO by weight percentage is greater than 9.5% and less than 12%.

13. The glass fiber according to claim 9, comprising the following components expressed as percentage by weight: TABLE-US-00019 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.1-0.9% CaO + MgO + SrO 20-24% TiO.sub.2 0.1-1.5% SrO 0.02-1.5% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

14. The glass fiber according to claim 9, comprising the following components expressed as percentage by weight: TABLE-US-00020 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.2-0.8% CaO + MgO + SrO 21-23.5% TiO.sub.2 0.1-1.5% SrO 0.02-1.5% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85,and wherein the content range of Bi.sub.2O.sub.3 by weight percentage is 0.02-0.35%.

15. The glass fiber according to claim 9, comprising the following components expressed as percentage by weight: TABLE-US-00021 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.1-0.9% CaO + MgO + SrO 20-24% TiO.sub.2 0.1-1.5% SrO 0-2% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

16. The composite material according to claim 10, wherein the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12,and wherein the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

17. The composite material according to claim 10, wherein the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12, and wherein the content range of CaO by weight percentage is greater than 9.5% and less than 12%.

18. The composite material according to claim 10, comprising the following components expressed as percentage by weight: TABLE-US-00022 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.1-0.9% CaO + MgO + SrO 20-24% TiO.sub.2 0.1-1.5% SrO 0.02-1.5% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

19. The composite material according to claim 10, comprising the following components expressed as percentage by weight: TABLE-US-00023 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.2-0.8% CaO + MgO + SrO 21-23.5% TiO.sub.2 0.1-1.5% SrO 0.02-1.5% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85,and wherein the content range of Bi.sub.2O.sub.3 by weight percentage is 0.02-0.35%.

20. The composite material according to claim 10, comprising the following components expressed as percentage by weight: TABLE-US-00024 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.1-0.9% CaO + MgO + SrO 20-24% TiO.sub.2 0.1-1.5% SrO 0-2% CeO.sub.2 0-1% wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and the weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

Description

PREFERRED EXAMPLE 1

[0047] The glass fiber composition according to the present invention comprises the following components expressed as percentage by weight:

TABLE-US-00005 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.1-0.9% CaO + MgO + SrO 20-24% TiO.sub.2 0.1-1.5% SrO 0-2% CeO.sub.2 0-1%

[0048] wherein, a weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and a the weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and a weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

PREFERRED EXAMPLE 2

[0049] The glass fiber composition according to the present invention comprises the following components expressed as percentage by weight:

TABLE-US-00006 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.2-0.8% CaO + MgO + SrO 21-23.5% TiO.sub.2 0.1-1.5% SrO 0.02-1.5% CeO.sub.2 0-1%

[0050] wherein, a weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12, and a weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and a weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

PREFERRED EXAMPLE 3

[0051] The glass fiber composition according to the present invention comprises the following components expressed as percentage by weight:

TABLE-US-00007 SiO.sub.2 58-62% Al.sub.2O.sub.3 14-16.5% Na.sub.2O 0.1-1% K.sub.2O 0.1-1% Fe.sub.2O.sub.3 0.1-1% Li.sub.2O + Bi.sub.2O.sub.3 0.2-0.8% CaO + MgO + SrO 21-23.5% TiO.sub.2 0.1-1.5% Bi.sub.2O.sub.3 0.02-0.35% SrO 0.02-1.5% CeO.sub.2 0.02-0.4%

[0052] wherein, a weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2-12, and a weight percentage ratio C2=(MgO+SrO)/CaO is 0.45-0.9, and a weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.85.

DETAILED DESCRIPTION OF THE INVENTION

[0053] 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 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. The basic concept of the present invention is that the components of the glass fiber composition expressed as percentage by weight are: 58-64% SiO.sub.2, 12-18% Al.sub.2O.sub.3, 0.1-1% Na.sub.2O, 0.1-1% K.sub.2O, 0.1-1% Fe.sub.2O.sub.3, 0.05-1% Li.sub.2O+Bi.sub.2O.sub.3, 19-25% CaO+MgO+SrO, 0.1-1.5% TiO.sub.2, 0-2% SrO and 0-1% Ce0.sub.2; wherein, a weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is greater than 1, and a weight percentage ratio C2=(MgO+SrO)/CaO is 0.4-1, and a weight percentage ratio C3=MgO/(MgO+SrO) is greater than 0.7. Each component with content above in the glass fiber composition according to the invention can reduce the forming temperature and liquidus temperature of the glass fiber, provide the melting, clarifying and fiberizing performances of the glass close to those of E-glass and the melting and reduce fiberizing temperatures significantly with respect to those of R-glass, and in the meantime, further reduce the amount of bubbles, viscosity and crystallization risk of the glass, thereby making it more suitable for large-scale production with refractory-lined furnaces.

[0054] The specific content values of SiO.sub.2, Al.sub.2O.sub.3, Na.sub.2O, K.sub.2O, Fe.sub.2O.sub.3, Li.sub.2O, Bi.sub.2O.sub.3, CaO, MgO, SrO, CeO.sub.2 and TiO.sub.2 in the glass fiber composition of the present invention are selected to be used in the examples and comparisons with traditional E glass and traditional R glass that are made in terms of the following six property parameters,

[0055] (1) Forming temperature, the temperature at which the glass melt has a viscosity of 10.sup.3 poise.

[0056] (2) Liquidus temperature, the temperature at which the crystal nucleuses begin to form when the glass melt cools off—i.e., the upper limit temperature for glass crystallization.

[0057] (3) ΔT 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.

[0058] (4) Filament strength, the tensile strength that a filament of glass fiber strand can withstand.

[0059] (5) Refractive index, the ratio of the speed of light in air to the speed of light in glass.

[0060] (6) Amount of bubbles, to be determined approximately in a procedure set out as follows: Use specific moulds to compress the 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 glass samples according to standard procedures up to the pre-set spatial temperature 1500° C. and then the glass sample is cooled 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.

[0061] The aforementioned six parameters and the methods of measuring them are well known to those skilled in the art. Therefore, the aforementioned parameters can be effectively used to explain the properties of the glass fiber composition of the present invention.

[0062] The specific procedures for the experiments are as follows: Each component can be acquired from the appropriate raw materials; the raw materials is mixed in the appropriate proportions so that each component reaches the final expected weight percentage; the mixed batch is melted and clarified; 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 deeply process these glass fibers to meet the expected requirements.

[0063] The exemplary embodiments of the glass fiber composition according to the present invention are given below.

EXAMPLE 1

[0064]

TABLE-US-00008 SiO.sub.2 59.5% Al.sub.2O.sub.3 15.5% Na.sub.2O  0.2% K.sub.2O  0.6% Fe.sub.2O.sub.3 0.35% Li.sub.2O 0.64% Bi.sub.2O.sub.3 0.32% CaO 11.9% MgO 8.9 SrO 2.0 TiO.sub.2  0.4% CeO.sub.2   0%

[0065] wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 2.0, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.91, and the weight percentage ratio C3=MgO/(MgO+SrO) is 0.82.

[0066] In Example 1, the measured values of the six parameters are respectively:

TABLE-US-00009 Forming temperature 1274° C. Liquidus temperature 1196° C. ΔT 78° C Filament strength 4175 MPa Refractive index 1.570 Amount of bubbles 4

EXAMPLE 2

[0067]

TABLE-US-00010 SiO.sub.2 60.0% Al.sub.2O.sub.3 15.5% Na.sub.2O 0.2% K.sub.2O 0.5% Fe.sub.2O.sub.3 0.42% Li.sub.2O 0.06% Bi.sub.2O.sub.3 0.02% CaO 11.9% MgO 8.9% SrO 1.0% TiO.sub.2 1.0% CeO.sub.2 0%

[0068] wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 3.0, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.83, and the weight percentage ratio C3=MgO/(MgO+SrO) is 0.90.

[0069] In Example 2, the measured values of the six parameters are respectively:

TABLE-US-00011 Forming temperature 1282° C. Liquidus temperature 1197° C. ΔT 85° C. Filament strength 4120 MPa Refractive index 1.568 Amount of bubbles 9

EXAMPLE 3

[0070]

TABLE-US-00012 SiO.sub.2 59.6% Al.sub.2O.sub.3 15.4% Na.sub.2O 0.2% K.sub.2O 0.2% Fe.sub.2O.sub.3 0.42% Li.sub.2O 0.72% Bi.sub.2O.sub.3 0.06% CaO 15.5% MgO 7.6% SrO 0% TiO.sub.2 0.3% CeO.sub.2 0%

[0071] wherein, the weight percentage ratio C1=Li.sub.2O/Bi.sub.2O.sub.3 is 12.0, and the weight percentage ratio C2=(MgO+SrO)/CaO is 0.49, and the weight percentage ratio C3=MgO/(MgO+SrO) is 1.0.

[0072] In Example 3, the measured values of the six parameters are respectively:

TABLE-US-00013 Forming temperature 1272° C. Liquidus temperature 1196° C. ΔT 76° C. Filament strength 4170 MPa Refractive index 1.569 Amount of bubbles 6

[0073] 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.

TABLE-US-00014 TABLE 1 A1 A2 A3 A4 A5 A6 A7 Component SiO.sub.2 59.6 59.6 59.5 60.0 60.0 59.6 59.6 Al.sub.2O.sub.3 15.5 15.6 15.5 15.5 15.5 15.4 15.4 CaO 15.1 14.1 11.9 11.9 11.9 15.5 15.5 MgO 7.5 8.6 8.9 8.9 8.9 7.6 7.6 SrO 0.5 0 2.0 1.5 1.0 0 0 Na.sub.2O 0.2 0.2 0.2 0.2 0.2 0.2 0.2 K.sub.2O 0.4 0.6 0.2 0.4 0.5 0.2 0.4 Li.sub.2O 0.35 0.4 0.64 0.6 0.06 0.72 0.45 Bi.sub.2O.sub.3 0.1 0.05 0.32 0.08 0.02 0.06 0.06 Fe.sub.2O.sub.3 0.4 0.38 0.35 0.42 0.42 0.42 0.42 TiO.sub.2 0.35 0.45 0.4 0.4 1.0 0.3 0.37 CeO.sub.2 0 0.02 0 0 0 0 0 Ratio C1 3.0 8.0 2.0 7.5 3.0 12.0 7.5 C2 0.53 0.61 0.91 0.87 0.83 0.49 0.49 C3 0.93 1.0 0.82 0.85 0.90 1.0 1.0 Parameter Forming 1273 1274 1274 1279 1282 1272 1276 temperature/ ° C. Liquidus 1195 1194 1196 1195 1197 1196 1196 temperature/ ° C. ΔT/° C. 78 80 78 84 85 76 80 Filament 4132 4143 4175 4182 4120 4170 4165 strength/MPa Refractive 1.568 1.569 1.570 1.570 1.568 1.569 1.569 index Amount of 6 4 4 6 7 6 7 bubbles/pcs

TABLE-US-00015 TABLE 2 Traditional Traditional Improved A8 A9 A10 A11 E glass R glass R glass Component SiO.sub.2 59.6 59.6 59.6 59.6 54.16 60 58 Al.sub.2O.sub.3 15.4 15.4 15.4 15.4 14.32 25 17.9 CaO 15.5 15.5 11.6 15.5 22.12 9 14.4 MgO 7.6 7.6 9.3 7.6 0.41 6 8.5 SrO 0 0 1.8 0 0 0 0 B.sub.2O.sub.3 0 0 0 0 7.6 0 0 Na.sub.2O 0.2 0.2 0.2 0.3 0.45 trace 0.1 amount K.sub.2O 0.54 0.6 0.6 0.6 0.25 trace 0.6 amount Li.sub.2O 0.24 0.12 0.4 0 0 0 0 Bi.sub.2O.sub.3 0.06 0.06 0 0.06 0 0 0 Fe.sub.2O.sub.3 0.42 0.42 0.4 0.42 0.35 trace trace amount amount TiO.sub.2 0.44 0.5 0.7 0.52 0.34 trace 0.2 amount CeO.sub.2 0 0 0 0 0 0 0 Ratio C1 4.0 2.0 — 0 0 0 0 C2 0.49 0.49 0.96 0.49 0.02 0.67 0.59 C3 1.0 1.0 0.84 1.0 1.0 1.0 1.0 Parameter Forming 1280 1282 1285 1284 1175 1430 1289 temperature/ ° C. Liquidus 1196 1198 1201 1201 1075 1350 1280 temperature/ ° C. ΔT/° C. 84 84 84 83 100 80 9 Filament 4132 4112 4080 4078 3265 4220 4089 strength/MPa Refractive 1.567 1.566 1.564 1.564 1.566 1.561 1.562 index Amount of 8 8 10 15 3 30 25 bubbles/pcs

[0074] It can be seen from the values in the above tables that, compared with the traditional R glass and the improved R glass, the glass fiber composition of the present invention has the following advantages: (1) much lower liquidus temperature, which helps to reduce crystallization risk and increase the fiber drawing efficiency; (2) much lower amount of bubbles, which indicates a significant quality improvement of the glass melt according to the present invention; (3) significantly improved glass refractive index, especially in the examples that meet the requirement of the ratio C 1, the improvements are more significant. At the same time, the filament strength of the present invention is similar to that of traditional R glass, and is much higher than that of traditional E glass. Specifically, compared with R glass, the glass fiber composition of the present invention has made a breakthrough in terms of the melting performance and refractive index of glass with significantly reduced amount of bubbles and remarkably improved refractive index under the same conditions. Furthermore, the overall technical solution of the present invention has a higher cost performance ratio compared with that of traditional R glass or improved R glass, thereby enabling the easy achievement of large-scale industrial production.

[0075] By using both Li.sub.2O and Bi.sub.2O.sub.3 and rationally determining the content ratio of Li.sub.2O to Bi.sub.2O.sub.3 as well as the content ratios among CaO, MgO and SrO, the present invention ensures that the resulted glass fiber has high mechanical properties and significantly improved refractive index; meanwhile, it greatly improves the melting and fiber forming efficiencies of glass by enabling a melting temperature and a fiberizing temperature significantly lower than those of traditional R glass, and further reduces the amount of bubbles and crystallization risk. Therefore, the glass fiber composition of the present invention is more suitable for large-scale production with refractory-lined furnaces.

[0076] The glass fiber composition according to the present invention can be used for making glass fibers having the aforementioned excellent properties.

[0077] The glass fiber composition according to the present invention can be used in combination with one or more organic and/or inorganic materials for preparing composite materials having excellent performances, such as glass fiber reinforced base materials.

[0078] Finally, what is 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 the phrase “contain a . . . ” do not rule out that there are other same factors in the process, method, article or equipment which include said factors.

[0079] 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 all the examples of the present invention.

INDUSTRIAL APPLICABILITY OF THE INVENTION

[0080] The glass fiber composition of the present invention can reduce the forming temperature and liquidus temperature of the glass, make the melting, clarifying and fiber forming properties be close to those of E glass, enable a melting temperature and a fiberizing temperature significantly lower than those of traditional R glass, and further reduces the amount of bubbles, viscosity and crystallization risk of glass. Therefore, the glass fiber composition of the present invention is more suitable for large-scale production with refractory-lined furnaces. The glass fiber composition according to the present invention can be used for making glass fibers having the aforementioned excellent properties, and the glass fiber composition according to the present invention can be used in combination with one or more organic and/or inorganic materials for preparing composite materials having excellent performances, such as glass fiber reinforced base materials.