Man-made vitreous fibres

• US 5,935,886 A
• Filed: 05/08/1997
• Issued: 08/10/1999
• Est. Priority Date: 11/08/1994
• Status: Expired due to Term

• Current Assignee: Rockwool International A/S
• Original Assignee: Rockwool International A/S
• Inventors: Jensen, Soren Lund, Christensen, Vermund Rust, Guldberg, Marianne
• Primary Examiner(s): MARCHESCHI, MICHAEL A
• Application Number:
  US08/836,537
• Time in Patent Office: 824 Days
• Field of Search: 501/35, 501/36, 501/38, 501/70, 501/73
• US Class Current: 501/36
• CPC Class Codes: C03C 13/00 Fibre or filament compositions manufacture of fibres or filaments C03B37/00
• CPC Class Codes: C03C 13/06 Mineral fibres, e.g. slag wool, mineral wool, rock wool
• CPC Class Codes: C03C 2213/02 Biodegradable glass fibres

Abstract

Man-made vitreous fibres has a solubility at pH 4.5 of at least 20 nm per day and a melt viscosity of 10-70 poise at 1,400° C. and are formed from a composition which includes 18 to 30% by weight Al₂ O₃.

Claims

1. A product comprising man-made vitreous fibres formed of a composition which includes, by weight of oxides,

SiO₂ 32 to 48%

Al₂ O₃ 18 to 30%

CaO 10 to 30%

MgO 5 to 20%

FeO 5 to below 10%

Na₂ O+K₂ O 0 to 10%

TiO₂ 0 to 4%

Other Elements 0 to below 8%

wherein the composition has a viscosity at 1400°

C. of 12 to 70 poise,

and wherein the fibres have (a) a dissolution rate of at least 20 nm per day when measured at a pH of 4.5, and (b) a sintering temperature of at least 800°

C.

2. A product according to claim 1 in which the amount of FeO is from 5 to below 8%.

3. A product according to claim 1 in which the amount of Al₂ O₃ is at least 19%.

4. A product according to claim 1 in which the amount of CaO is at least 18%.

5. A product according to claim 1 in which the amount of SiO₂ is at least 35%.

6. A product according to claim 1 in which the composition has a viscosity of 15 to 40 poise at 1400°

C.

7. A product according to claim 1 in which the composition has a viscosity of 18 to 30 poise at 1400°

C.

8. A product according to claim 1 in which the fibres have a sintering temperature of at least 1000°

C.

9. A product according to claim 1 in which the amount of SiO₂ +Al₂ O₃ is 60 to 75% and the amount of Na₂ O+K₂ O is 0 to 7%.

10. A product according to claim 1 in which the amount of SiO₂ is 34 to 45%, the amount of Al₂ O₃ is 19 to 28%, the amount of CaO is 14 to 25%, the amount of MgO is 6 to 15%, the amount of FeO is 5 to 8%, and the amount of Na₂ O+K₂ O is below 5%.

11. A product according to claim 1 in which the fibres have a dissolution rate at pH 7.5 of less than 15 nm per day.

12. A product according to claim 1 in which the amount of SiO₂ +Al₂ O₃ is 55 to 75%.

13. A product according to claim 1 in which the amount of SiO₂ +Al₂ O₃ is 61 to 68%.

14. A product according to claim 1 in which the amount of Al₂ O₃ is 20 to 26%.

15. A product according to claim 1 in which the amount of MgO is at least 8% and the amount of FeO is from 6 to below 10%.

16. A product according to claim 1 in which the composition has a liquidus temperature of 1240 to 1340°

C.

17. A product according to claim 1 in which the amount of SiO₂ does not exceed 42%.