US4054434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of glass fibres
Assignee: Fibreglass Ltd
•
Filing: 1976-04-29
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Granted: 1977-10-18
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Expires: 1996-04-29
Abstract
Abstract The disclosed invention pertains to a process for melting glass in which scrap glass fibers containing carbonaceous material to provide a carbon content of 0.4%-0.04% in a batch is combined with batch materials in which the scrap amounts to 5%-25% by the weight of the batch. The batch is melted under oxidizing conditions and the resultant melt is used to form glass fibers.
Inventors
- 👤 John Stuart Thomas
- 👤 Allan Frank Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:33
CPC Classifications
C; C03; C03B; C03B1/00; C03B37/00; C03B37/10; C03C; C03C1/00; C03C1/002; Y; Y02; Y02P; Y02P40/00; Y02P40/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
147 words
A process for forming glass fibers comprising: collecting scrap glass fiber material derived from at least one glass fiberizing process, said glass fiber material containing on its surface a proportion of non-mineral, carbonaceous material; reducing the scrap glass fiber material to a finely divided, milled form; preparing a batch of glass fiber forming material by mixing between 5% and 25% by weight of said finely divided scrap with new material; said proportion of non-mineral, carbonaceous material on said scrap glass fiber being sufficient to provide a carbon content of 0.4% to 0.05% in said batch; feeding the batch so formed to a glass melting tank and converting the batch to a glass melt; maintaining oxidizing conditions within the glass melt during the melting operation, and transferring the melt to a fiberizing device and converting the melt into glass fibers by attenuating glass streams leaving the fiberizing device.
Claim 2
Dependent Claim
147 words
A process for forming glass fibers comprising: collecting scrap glass fiber material derived from at least one glass fiberizing process, said glass fiber material containing on its surface a proportion of non-mineral, carbonaceous material; reducing the scrap glass fiber material to a finely divided, milled form; preparing a batch of glass fiber forming material by mixing between 5% and 25% by weight of said finely divided scrap with new material; said proportion of non-mineral, carbonaceous material on said scrap glass fiber being sufficient to provide a carbon content of 0.4% to 0.05% in said batch; feeding the batch so formed to a glass melting tank and converting the batch to a glass melt; maintaining oxidizing conditions within the glass melt during the melting operation, and transferring the melt to a fiberizing device and converting the melt into glass fibers by attenuating glass streams leaving the fiberizing device.
Claim 3
Dependent Claim
19 words
A process as claimed in claim 1 in which the non-mineral material is distributed substantially uniformly in the batch.
Claim 4
Dependent Claim
34 words
A process as claimed in any one of claims 1 in which the fibre is added to the tank without any treatment to the fibre other than converting it to a finely divided form.
Claim 5
Dependent Claim
21 words
A process as claimed in any one of claims 1 in which the fibre is heated before addition to the tank.
Claim 6
Dependent Claim
22 words
A process as claimed in claim 1 in which the tank operating conditions are altered by adding sodium nitrate to the batch.
Claim 7
Dependent Claim
37 words
A process as claimed in claim 4, in which the binder is cured by the heating of the fibre and the fibre is then finely divided by a milling process before being fed to the melting tank.
Claim 8
Dependent Claim
31 words
A process as claimed in claim 1 in which the binder of the scrap fibre in the batch is left uncured immediately prior to feeding the batch to the glass melt.
Claim 9
Dependent Claim
24 words
A process as claimed in claim 1 in which the finely divided fibre comprises particles having a mean particle size less than 500 microns.
Claim 10
Dependent Claim
24 words
A process as claimed in claim 8 in which the finely divided fibre comprises particles has a mean particle size less than 60 microns.
Claim 11
Dependent Claim
25 words
A process as claimed in claim 4 in which substantially all the non-mineral matter is converted to carbon prior to feeding to the melting tank.
References Cited (Backward Citations)
US3382135A
Cited
US3830749A
Cited
US3789018A
Cited
US3852108A
Cited
US3847664A
Cited
US3944713A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-17 | 1981-04-18 | 1981-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-17 | 1985-04-18 | 1985-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-17 | 1989-04-18 | 1989-10-18 | $7700.00 | Window Closed / Lapsed |