Glass yarns capable of reinforcing organic and/or inorganic materials
View Patent ↗The invention relates to a glass yarn capable of being obtained by a method consisting of mechanically drawing molten glass threads flowing from orifices disposed at the base of a die, of which the chemical composition is substantially free from boron oxide and comprises the following constituents within the limits defined hereinafter expressed in percentages by weight: SiO 2 40 to 50 Al 2 O 3 18 to 28 CaO 4 to 15 MgO 0 to 6 Na 2 O 10 to 14 Na 2 O + K 2 O + Li 2 O 13 to 20 It also relates to composites containing such yarns.
1. A glass yarn obtained by a method consisting of mechanically drawing molten glass threads flowing from orifices disposed at the base of a die, of which the chemical composition is substantially free from boron oxide and comprises the following constituents within the limits defined hereinafter expressed in percentages by weight:
SiO 2
40 to 50
Al 2 O 3
18 to 28
CaO
4 to 15
MgO
0 to 6
Na 2 O
11 to 13.9
Na 2 O + K 2 O + Li 2 O
13 to 20.8.
2. The glass yarn as claimed in claim 1 , wherein the SiO 2 content is less than or equal to 49% and greater than or equal to 42%.
3. The glass yarn as claimed in claim 1 , wherein the Al 2 O 3 content is less than or equal to 27% and greater than or equal to 19%.
4. The glass yarn as claimed in claim 1 , wherein the sum SiO 2 +Al 2 O 3 is greater than or equal to 66% and less than or equal to 75%.
5. The glass yarn as claimed in claim 1 , wherein the CaO content is greater than or equal to 5% and less than or equal to 14%.
6. The glass yarn as claimed in claim 1 , wherein the MgO content is greater than or equal to 1% and less than or equal to 5%.
7. The glass yarn as claimed in claim 1 , wherein the sum of the CaO and MgO contents is less than or equal to 15%.
8. The glass yarn as claimed in claim 1 , wherein the Na 2 O content is greater than or equal to 11% and less than or equal to 13.5%.
9. The glass yarn as claimed in claim 1 , wherein the K 2 O content is greater than or equal to 1% and less than or equal to 8%.
10. The glass yarn as claimed in claim 1 , wherein the total content of alkali metal oxides is less than or equal to 19% and greater than or equal to 14%.
11. The glass yarn as claimed in claim 1 , wherein the sum of the contents of SiO 2 , Al 2 O 3 , CaO, MgO, Na 2 O and K 2 O is greater than or equal to 95%.
12. The glass yarn as claimed in claim 1 , which comprises:
Na 2 O
11 to 13.7
Na 2 O + K 2 O + Li 2 O
13 to 20.
13. A composite of glass yarns and organic and/or inorganic materials comprising glass yarns as defined in claim 1 .
14. A method for producing glass yarns as claimed in claim 1 , comprising drawing in the form of one or more webs of continuous filaments from a multiplicity of molten glass threads flowing from a multiplicity of orifices disposed at the base of one or more dies, and assembling said filaments into one or more yarns, collected on a moving support.