US3671411A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of carbon or graphite fibers and yarns for use in fiber reinforced composites
Assignee: United States Department of the Air Force
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Filing: 1970-03-03
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Granted: 1972-06-20
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Expires: 1990-03-03
Abstract
Abstract Carbon fiber or yarn as used in fiber reinforced composites is electrolytically treated to improve the surface characteristics and thereby to improve its bonding or adhesion to the matrix material. By this improved bonding, shear strengths of resultant fiber resin or plastic composites have been more than doubled. The electrolytic treatment is conducted by using the fiber or yarn as the anode and using en electrolyte such as an aqueous caustic solution.
Inventors
- 👤 James D Ray
- 👤 Samuel Steingiser
- 👤 Robert A Cass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:44
CPC Classifications
D; D01; D01F; D01F11/00; D01F11/10; D01F11/16
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
19 words
The process accordiNg to claim 1 in which said fiber is passed through said electrolyte as a continuous strand.
Claim 2
Dependent Claim
24 words
The process according to claim 1 in which said current density is in the range of about 0.001 to 0.003 ampere per square centimeter.
Claim 3
Dependent Claim
56 words
The process according to claim 1 in which said electrolyte is an aqueous solution of a compound selected from the group consisting of sodium hydroxide, potassium hydroxide, phosphoric acid, nitric acid, boric acid and sulfuric acid and the concentration of said compound in said solution is in the range of about 0.5 to 20 weight percent.
Claim 4
Dependent Claim
174 words
A process for improving the bonding properties of a carbon or graphite fiber to a resin or plastic matrix which comprises passing a continuous strand of said fiber through a bath containing an aqueous electrolyte, said electrolyte having an electrode immersed therein and connected to a negative pole of a direct current source and said strand prior to entry into said bath passing over a graphite roller connected to a positive pole of said direct current source; controlling the speed at which said strand is passed through the electrolyte so that it is in contact therewith and subjected to an electrolytic reaction for a period in the range of about 25 to 500 seconds whereby negative ions of the electrolyte are attracted to said fiber and nascent oxygen is produced at its surface, thereby modifying the fiber surface; and controlling current density used in the electrolytic reaction so that it is in the range of about 0.0005 to 0.005 ampere per square centimeter of surface area of the fiber in contact with said electrolyte.
References Cited (Backward Citations)
US2807577A
Cited
US3323869A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |