Glass yarns capable of reinforcing organic and/or inorganic materials
View Patent ↗The invention relates to a glass strand, the chemical composition of which is substantially free of boron oxide and comprises the following constituents, in the limits defined below expressed as percentages by weight: SiO 2 55 to 65 Al 2 O 3 9 to 16 CaO 15 to 26 MgO 1 to 5 BaO + SrO 0.5 to 5 Na 2 O + K 2 O + Li 2 O 0 to 2 TiO 2 0 to 1 ZnO 0 to 2 ZrO 2 0 to 2. It also relates to composites comprising such strands.
1. A glass strand, the chemical composition of which is substantially free of boron oxide and comprises:
SiO 2
55 to 65
Al 2 O 3
9 to 16
CaO
15 to 26
MgO
1 to 5
BaO + SrO
0.5 to 5
Na 2 O + K 2 O + Li 2 O
0 to 2
TiO 2
0 to 1
ZnO
0 to 2
ZrO 2
0 to 2
wherein the limits are expressed as percentages by weight.
2. The glass strand as claimed in claim 1 , wherein the SiO 2 content is between 60 and 62%.
3. The glass strand as claimed in claim 1 , wherein the Al 2 O 3 content is between 10 and 12.5%.
4. The glass strand as claimed claim 1 , wherein the CaO content is equal to or less than 21.8%.
5. The glass strand as claimed in claim 1 , wherein the MgO content is equal to or greater than 2%.
6. The glass strand as claimed claim 1 , wherein the ratio of the SiO 2 content to the CaO+MgO sum is equal to or greater than 2.4.
7. The glass strand as claimed in claim 1 , wherein the BaO+SrO sum is between 0.5 and 1.5%.
8. A composite, comprising glass strands as defined in claim 1 .
9. A process for manufacturing the glass strands as claimed in claim 1 , comprising attenuating a multiplicity of molten glass streams emanating from a multiplicity of orifices disposed over the base of one or more bushings into the form of one or more webs of continuous filaments and of assembling said filaments into one or more strands that are collected on a moving support.
10. The glass strand as claimed in claim 1 , comprising at least one of:
Na 2 O + K 2 O + Li 2 O
0.01 to 2,
TiO 2
0.5 to 1
ZnO
0.01 to 2
ZrO 2
0.5 to 2,
wherein the limits are expressed as percentages by weight.
11. The glass strand as claimed in claim 1 , comprising
ZnO 0.01 to 2
expressed as percentages by weight.
12. The glass strand as claimed in claim 1 , comprising
ZrO 2 0.5 to 2
expressed as a percentage by weight.
13. The glass strand as claimed in claim 1 , comprising
Na 2 O+K 2 O+Li 2 O 0.01 to 2
expressed as a percentage by weight.
14. The glass strand as claimed in claim 1 , comprising
TiO 2 0.5 to 1
expressed as a percentage by weight.
15. The glass strand as claimed in claim 1 , comprising
BaO+SrO 1.0 to 5
expressed as a percentage by weight.
16. The glass strand as claimed in claim 1 , comprising
BaO 1.1 to 1.5.