US4145202A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for reprocessing glass fibers
Assignee: PPG Industries Inc
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Filing: 1978-04-26
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Granted: 1979-03-20
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Expires: 1998-04-26
Abstract
Abstract A method is disclosed for processing waste glass strands and/or fibrous filaments which are produced in the course of operating a glass fiber forming plant for subsequent reuse as batch ingredients for a glass fiber forming process. The method described involves controlled thermal treatment of the waste glass strands and/or filaments to produce particulate glass which can be recycled to a fiber glass forming furnace. The reprocessing of waste glass strands and/or filaments reduces substantially the raw material cost involved in feeding glass batch ingredients to a glass fiber forming operation. Apparatus for accomplishing the reprocessing of the waste glass filaments and/or strands in accordance with the method disclosed is also described.
Inventors
- 👤 Martin A. Grodin
- 👤 Herbert W. Barch
- 👤 Frank E. Harvey
- 👤 Patrick C. Chardello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:42
CPC Classifications
C; C03; C03C; C03C1/00; C03C1/02; C03C1/024; C03B; C03B37/00; C03B37/10; C03B37/16; C03C1/002; C03C25/00; C03C25/002
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
126 words
A method of treating waste glass filaments and/or strands having organic coatings present thereon comprising heating the glass filaments and/or strands in a controlled thermal environment wherein the filaments and/or strands are heated to a first thermal treatment temperature for a sufficient period of time to remove substantially all the moisture therefrom, raising the temperature of the filaments and/or strands after the moisture has been removed to a second thermal treatment temperature sufficient to volatilize the organic components of coatings present, then raising the temperature of the filaments and/or strands to a final thermal treatment temperature sufficient to incinerate any residual material on the surface thereof while maintaining the filaments and/or strands at temperatures below the softening point thereof and collecting the resulting filaments and/or strands.
Claim 2
Independent Claim
126 words
A method of treating waste glass filaments and/or strands having organic coatings present thereon comprising heating the glass filaments and/or strands in a controlled thermal environment wherein the filaments and/or strands are heated to a first thermal treatment temperature for a sufficient period of time to remove substantially all the moisture therefrom, raising the temperature of the filaments and/or strands after the moisture has been removed to a second thermal treatment temperature sufficient to volatilize the organic components of coatings present, then raising the temperature of the filaments and/or strands to a final thermal treatment temperature sufficient to incinerate any residual material on the surface thereof while maintaining the filaments and/or strands at temperatures below the softening point thereof and collecting the resulting filaments and/or strands.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the filaments and/or strands are cut to a length of between about 1.0 and 2.0 inches (2.54 and 5.08 centimeters) prior to heating.
Claim 4
Dependent Claim
86 words
The method of claim 1 wherein the strands are heated and maintained at a temperature between about 200° F. and 350° F. (93.3° C. and 176.7° C.) in the first thermal treatment, strands are heated and maintained at a temperature of between about 500° F. and 700° F. (260° C. and 371.1° C.) in the next thermal treatment and in the final thermal stage the strand is heated and maintained at a temperature of between about 900° F. and 1250° F. (482.2° C. and 676.7° C.).
Claim 5
Dependent Claim
19 words
The method of claim 1 comprising further grinding the filaments and/or strands after they leave the thermal treatment steps.
Claim 6
Dependent Claim
18 words
The method of claim 2 wherein the glass filaments and strands are fed to the thermal treatment continuously.
Claim 7
Dependent Claim
21 words
The method of claim 3 wherein the glass strands are cut to short lengths and fed continuously to the thermal treatment.
Claim 8
Dependent Claim
17 words
The method of claim 5 wherein the filaments and/or strands collected are subjected to a grinding step.
Claim 9
Dependent Claim
16 words
The method of claim 6 wherein the filaments and or strands collected are subjected to grinding.
Claim 10
Dependent Claim
30 words
The method of claim 4 wherein said filaments and/or strands are further ground to produce a powder therefrom having particles ranging between about 60 mesh and 325 mesh or less.
Claim 11
Dependent Claim
22 words
The method of claim 1 further comprising feeding said filaments and/or strands directly to a glass melting furnace after they are collected.
Claim 12
Dependent Claim
23 words
The method of claim 4 further comprising directly feeding said filaments and/or strands to a glass melting furnace after they are further ground.
Claim 13
Dependent Claim
20 words
The method of claim 1 further comprising storing said filaments and/or strands in a batch house after they are heated.
Claim 14
Dependent Claim
22 words
The method of claim 4 further comprising storing said ground filaments and/or strands in a batch house after they are further ground.
References Cited (Backward Citations)
US2563085A
Cited
US2666720A
Cited
US2674549A
Cited
US3253897A
Cited
US3155475A
Cited
US3375155A
Cited
US3346417A
Cited
US3503790A
Cited
US3682666A
Cited
US3607190A
Cited
US3502456A
Cited
US3744779A
Cited
US3627289A
Cited
US3753743A
Cited
US3734774A
Cited
US3852108A
Cited
US3847664A
Cited
US3912534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |