Glass yarn for reinforcing organic and/or inorganic materials
View Patent ↗The invention relates to glass reinforcement strands, the composition of which comprises the following constituents in the limits defined below, expressed as percentages by weight: 58 to 63% SiO 2 ; 10 to 16% Al 2 O 3 ; 16 to 23% CaO; 0.5 to 3.5% MgO; 0 to 2% Na 2 O+K 2 O+Li 2 O; 1 to 1.5% TiO 2 ; 0 to 1.5% B 2 O 3 ; 0 to 0.4% Li 2 O; 0 to 0.4% ZnO; 0 to 1% MnO; and 0 to 0.5% F. These strands have improved properties in terms of mechanical strength, acid resistance and high-temperature resistance for a low-cost composition. The invention also relates to a process for producing the said strands and to the composition allowing them to be produced.
1. A glass strand having a composition comprising the following constituents in the limits defined below, expressed as percentages by weight:
SiO 2
58 to 63
Al 2 O 3
10 to 16
CaO
16 to less than 23
MgO
0.5 to less than 3.5
Na 2 O + K 2 O + Li 2 O
0 to 2
TiO 2
greater than 1 but less than 1.5
B 2 O 3
0 to 1.5
Li 2 O
0 to 0.4
ZnO
0 to 0.4
MnO
0 to 1
F
0 to 0.5 and
between 10 and 100 ppm of cobalt oxide (CoO).
2. The glass strand according to claim 1 , wherein the SiO 2 content is strictly greater than 60%.
3. The glass strand according to claim 1 , wherein the TiO 2 content is greater than or equal to 1.1 % and less than or equal to 1.4%.
4. The glass strand according to claim 1 , wherein the MgO content is between 2.2 and 2.8%.
5. The glass strand according to claim 1 , wherein the boric anhydride (B 2 O 3 ) content does not exceed 0.5%.
6. A composite comprising a glass strand and an organic or inorganic material, or mixtures thereof, wherein the glass strand is as defined in claim 1 .
7. A fitting for an exhaust system, comprising a glass strand as defined in claim 1 .
8. A glass composition suitable for producing a glass reinforcement strand, which comprises the following constituents in the limits defined below, expressed as percentages by weight:
SiO 2
58 to 63
Al 2 O 3
10 to 16
CaO
16 to less than 23
MgO
0.5 to less than 3.5
Na 2 O + K 2 O + Li 2 O
0 to 2
TiO 2
greater than 1 but less than 1.5
B 2 O 3
0 to 1.5
Li 2 O
0 to 0.4
ZnO
0 to 0.4
MnO
0 to 1
F
0 to 0.5 and
between 10 and 100 ppm of cobalt oxide (CoO).
9. A process for manufacturing a glass strand comprising:
attenuating into the form of one or more webs of continuous filaments from a multiplicity of molten glass streams emanating from a multiplicity of orifices placed at the base of one or more bushings, and
assembling the filaments into one or more strands that are collected on a moving support, the molten glass feeding the bushings having a composition according to claim 8 .