US2506364A - Heat-treating aluminum foil - Google Patents
Heat-treating aluminum foil Download PDFInfo
- Publication number
- US2506364A US2506364A US12897A US1289748A US2506364A US 2506364 A US2506364 A US 2506364A US 12897 A US12897 A US 12897A US 1289748 A US1289748 A US 1289748A US 2506364 A US2506364 A US 2506364A
- Authority
- US
- United States
- Prior art keywords
- aluminum foil
- atmosphere
- foil
- heat
- volume
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/02—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working in inert or controlled atmosphere or vacuum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
Definitions
- This invention relates to the heat treatment of aluminum foil, either in roll or stacked form,
- One of the steps in the manufacture of aluminum foil is an annealing operation which is used to impart ductility to the foil and to remove lubricants from the surface of the foil.
- the lubricant which may comprise a hydrocarbon oil, a metallic soap solution or the like, is applied to the foil to control friction and heat generated during the rolling process.
- the ordinary processes of annealing have not been successful in removing all of the lubricant Without resulting in the oxidation of the lubricant and the aluminum surfaces. The net result is that the layers of the foil stick together, thus resulting in severe losses during subsequent unwinding and rewinding.
- the sticking of aluminum foil during the annealing process may be prevented by heating it in an atmosphere of controlled composition, characterized by specified limits on the percentage of the gas constituents.
- the atmosphere used may be reducing, neutral, or oxidizing in chemical nature, to the limited extent of certan prescribed percentages of the gas constituents.
- th controlled atmosphere comprises not less than 70% by volume of nitrogen, not more than by volume of carbon dioxide, not more than 1% by volume of oxygen, less than 2.1 by volume of water vapor, the remainder comprising reducing gases.
- the primary object of this invention to provide an atmosphere in which the annealing of aluminum foil is carried out in an atmosphere comprising primarily nitrogen in a major proportion and reducing gases, oxidizing gases, or both in definitely limited quantities.
- While th method of preparing the above atmosphere is not critical to the present invention, such an atmosphere can be obtained by incompletely burning a hydrocarbon mixture such as city gas in a reaction chamber.
- a hydrocarbon mixture such as city gas
- the composition of the resulting gases coming from the reaction chamber may be controlled so as to produce any desired composition within the range set forth above.
- the ratio of air to gas is such that nearly perfect combustion is obtained the resulting gas becomes strongly oxidizing in nature.
- the resulting atmosphere will be high in nitrogen and will also contain more than 10% carbon dioxode.
- the nitrogen and carbon dioxide content will be lower.
- the nitrogen content should not drop below 70% by volume of the total atmosphere.
- the oxygen content of the atmosphere be maintained within predetermined limits or sticking of the foil will result.
- the oxygen content should be less than 1%, preferably in amounts of about 0.6%. This sticking of the foil also accounts for the 10% limitation on the content of the carbon dioxide as well as the limitation on the amount of water vapor that may be present.
- the aluminum foil is placed in an enclosed space and enveloped in a controlled atmosphere as outlined above. This atmosphere is maintained in the enclosed spaced during the entire period of the annealing operation. After the annealing operation is completed the aluminum foil is allowed to cool and may then be removed from the heating chamber. No further treatment of the aluminum foil is necessary to facilitate its being unwound and rewound into capacitor rolls without the interlayer sticking that has been so prevalent in the processes employed prior to our present invention.
- the method of preventing interlayer sticking during the heat treatmentof aluminum foil in coil form which comprises heating the coil :at annealing temperatures in a closed chamber in an atmosphere consisting of the incomplete combustion products of a mixture of gaseous hydrocarbons, said atmosphere consisting by volume of not less than 70% nitrogen, not more than 10% carbon dioxide, not more than 1% oxygen, less than 2.1% water vapor and the remainder a mixture of the reducing gases, carbon monoxide, hydrogen and methane.
Landscapes
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Description
Patented May '2, 11950 UNITED STAT HEAT-TREATING ALUMINUM FOIL Alexander G. Jarvieand Cyril H. Hannon, Pittsfield, Mass, assignors to General Electric Company, a corporation of New York N Drawing. Application March 3, 1948, Serial No. 12,897
1 Claim.
This invention relates to the heat treatment of aluminum foil, either in roll or stacked form,
in an atmosphere and, more particularly, in an atmospher designed to prevent sticking of adjacent layers of aluminum foil during and after heat treatment.
One of the steps in the manufacture of aluminum foil is an annealing operation which is used to impart ductility to the foil and to remove lubricants from the surface of the foil. The lubricant, which may comprise a hydrocarbon oil, a metallic soap solution or the like, is applied to the foil to control friction and heat generated during the rolling process. The ordinary processes of annealing have not been successful in removing all of the lubricant Without resulting in the oxidation of the lubricant and the aluminum surfaces. The net result is that the layers of the foil stick together, thus resulting in severe losses during subsequent unwinding and rewinding. This result is particularly objectionable in the subsequent use of the annealed foil in the manufacture of capacitor rolls Where the winding of such rolls is carried on in high speed Windin'g machines. In such case any tendency of the foil to stick seriously interferes with the winding operation and causes excessive breaking and uneven winding of the foil.
We have discovered that the sticking of aluminum foil during the annealing process may be prevented by heating it in an atmosphere of controlled composition, characterized by specified limits on the percentage of the gas constituents. We have discovered that the atmosphere used may be reducing, neutral, or oxidizing in chemical nature, to the limited extent of certan prescribed percentages of the gas constituents.
According to our invention th controlled atmosphere comprises not less than 70% by volume of nitrogen, not more than by volume of carbon dioxide, not more than 1% by volume of oxygen, less than 2.1 by volume of water vapor, the remainder comprising reducing gases.
It is, therefore, the primary object of this invention to provide an atmosphere in which the annealing of aluminum foil is carried out in an atmosphere comprising primarily nitrogen in a major proportion and reducing gases, oxidizing gases, or both in definitely limited quantities.
As an example of our invention, an atmosphere having the following composition has been found to be satisfactory for annealing aluminum foil in stacked or coil form whereby the foil is prevented from sticking during and after the annealing operation:
Not less than by volume of nitrogen Less than 1% by volume of oxygen Less than 2.1% by volume of water vapor Not over 10% by volume of carbon dioxide The remainder comprising reducing gases, such as hydrogen, carbon monoxide and methane.
While th method of preparing the above atmosphere is not critical to the present invention, such an atmosphere can be obtained by incompletely burning a hydrocarbon mixture such as city gas in a reaction chamber. By varying the proportions of air and gas burned in a manner well understood by those skilled in the art, the composition of the resulting gases coming from the reaction chamber may be controlled so as to produce any desired composition within the range set forth above. Where the ratio of air to gas is such that nearly perfect combustion is obtained the resulting gas becomes strongly oxidizing in nature. Thus, if nearly all the hydrogen, carbon monoxide and methane are consumed, the resulting atmosphere will be high in nitrogen and will also contain more than 10% carbon dioxode. On the other hand, if such gaseous mixture is partially burned by using a smaller amount of air, the nitrogen and carbon dioxide content will be lower. For the purposes of our invention, it is essential that the nitrogen content should not drop below 70% by volume of the total atmosphere. It is also necessary that the oxygen content of the atmosphere be maintained within predetermined limits or sticking of the foil will result. As previously stated, the oxygen content should be less than 1%, preferably in amounts of about 0.6%. This sticking of the foil also accounts for the 10% limitation on the content of the carbon dioxide as well as the limitation on the amount of water vapor that may be present.
In racticing the method of our invention, with the view in mind of preventing the adjacent layers of the aluminum foil from sticking during and after the annealing step, the aluminum foil is placed in an enclosed space and enveloped in a controlled atmosphere as outlined above. This atmosphere is maintained in the enclosed spaced during the entire period of the annealing operation. After the annealing operation is completed the aluminum foil is allowed to cool and may then be removed from the heating chamber. No further treatment of the aluminum foil is necessary to facilitate its being unwound and rewound into capacitor rolls without the interlayer sticking that has been so prevalent in the processes employed prior to our present invention.
It is to be understood that the above description is merely illustrative and that the invention is not to be limited in any respect except as defined in the following claim.
What we claim as new and desire to secure by Letters Patent of the United States, is:
The method of preventing interlayer sticking during the heat treatmentof aluminum foil in coil form which comprises heating the coil :at annealing temperatures in a closed chamber in an atmosphere consisting of the incomplete combustion products of a mixture of gaseous hydrocarbons, said atmosphere consisting by volume of not less than 70% nitrogen, not more than 10% carbon dioxide, not more than 1% oxygen, less than 2.1% water vapor and the remainder a mixture of the reducing gases, carbon monoxide, hydrogen and methane.
ALEXANDER G. JARVIE.
CYRIL H. HANNON.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES "PATENTS Name Date Schon Feb. 13, 1940 OTHER REFERENCES Controlledntmospheres for the Heat Treatment ofMetalspages 93, 94, and 282. Edited by Jenkins. Published in 1946 by Chapman and Hall, Ltd, London, England.
Number
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12897A US2506364A (en) | 1948-03-03 | 1948-03-03 | Heat-treating aluminum foil |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12897A US2506364A (en) | 1948-03-03 | 1948-03-03 | Heat-treating aluminum foil |
Publications (1)
Publication Number | Publication Date |
---|---|
US2506364A true US2506364A (en) | 1950-05-02 |
Family
ID=21757269
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12897A Expired - Lifetime US2506364A (en) | 1948-03-03 | 1948-03-03 | Heat-treating aluminum foil |
Country Status (1)
Country | Link |
---|---|
US (1) | US2506364A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2671997A (en) * | 1949-11-05 | 1954-03-16 | Colgate Palmolive Co | Method of treating collapsible aluminum tube containers |
US3052014A (en) * | 1958-04-21 | 1962-09-04 | Aluminum Co Of America | Flame treatment of aluminum |
US3061485A (en) * | 1960-12-12 | 1962-10-30 | Reynolds Metals Co | Residual lubricant removal from aluminum foil |
US3084080A (en) * | 1958-07-17 | 1963-04-02 | Aluminum Co Of America | Production of void-free aluminum and aluminum base alloy articles |
US3148099A (en) * | 1961-07-03 | 1964-09-08 | Graphtex Inc | Method of making aluminum foil nameplate |
US3197347A (en) * | 1961-12-14 | 1965-07-27 | Alusuisse | Treatment of aluminum foil for electrolytic capacitors |
US3284256A (en) * | 1960-10-10 | 1966-11-08 | Commissariat Energie Atomique | Method of manufacturing a composite, heat-insulating material of the type formed by stacking foils of oxidisable metal |
US3326679A (en) * | 1965-03-12 | 1967-06-20 | Alloys Res & Mfg Corp | Process for improved sintering |
US4840680A (en) * | 1984-04-05 | 1989-06-20 | Societe Stein Heurtey, Z.A.I. | Method for degreasing a cold rolled metallic band |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2189836A (en) * | 1936-08-12 | 1940-02-13 | Crown Cork & Seal Co | Method of strip annealing aluminum foil |
-
1948
- 1948-03-03 US US12897A patent/US2506364A/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2189836A (en) * | 1936-08-12 | 1940-02-13 | Crown Cork & Seal Co | Method of strip annealing aluminum foil |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2671997A (en) * | 1949-11-05 | 1954-03-16 | Colgate Palmolive Co | Method of treating collapsible aluminum tube containers |
US3052014A (en) * | 1958-04-21 | 1962-09-04 | Aluminum Co Of America | Flame treatment of aluminum |
US3084080A (en) * | 1958-07-17 | 1963-04-02 | Aluminum Co Of America | Production of void-free aluminum and aluminum base alloy articles |
US3284256A (en) * | 1960-10-10 | 1966-11-08 | Commissariat Energie Atomique | Method of manufacturing a composite, heat-insulating material of the type formed by stacking foils of oxidisable metal |
US3061485A (en) * | 1960-12-12 | 1962-10-30 | Reynolds Metals Co | Residual lubricant removal from aluminum foil |
US3148099A (en) * | 1961-07-03 | 1964-09-08 | Graphtex Inc | Method of making aluminum foil nameplate |
US3197347A (en) * | 1961-12-14 | 1965-07-27 | Alusuisse | Treatment of aluminum foil for electrolytic capacitors |
US3326679A (en) * | 1965-03-12 | 1967-06-20 | Alloys Res & Mfg Corp | Process for improved sintering |
US4840680A (en) * | 1984-04-05 | 1989-06-20 | Societe Stein Heurtey, Z.A.I. | Method for degreasing a cold rolled metallic band |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2506364A (en) | Heat-treating aluminum foil | |
US2287467A (en) | Process of producing silicon steel | |
US2257668A (en) | Formation of protective layers on iron and steel articles | |
EP0692545A1 (en) | Heat-treatment installation | |
KR890013200A (en) | Manufacturing method of oriented electrical steel sheet with high magnetic flux density | |
TWI615485B (en) | Grain oriented electrical steel with improved forsterite coating characteristics | |
US1979820A (en) | Heat treatment | |
US3130095A (en) | Production of oriented silicon-iron sheets by secondary recrystallization | |
US3615903A (en) | High-purity ferrous material and method of making it | |
US2533351A (en) | Formation of glass film on silicon steel by strip annealing | |
US3379581A (en) | Desulfurizing coating for ferrous material and method of using it | |
CA1154364A (en) | Process for degrease annealing thin strip and foil made of aluminum and aluminum alloys | |
US3061485A (en) | Residual lubricant removal from aluminum foil | |
US2050305A (en) | Process of heat treating steel | |
US3196054A (en) | Process of decarburizing and annealing of open coil silicon-iron sheet stock without intervening surface treatment | |
US3116179A (en) | Production of non-oriented ferrous magnetic materials | |
US2304518A (en) | Silicon electrical steel | |
US5783000A (en) | Method for heat treatment of steel, and products of steel | |
US3531333A (en) | Method of heat treating steel strip or the like | |
US1787977A (en) | Process of heat-treating steel | |
US2229642A (en) | Process of making electrical sheets | |
US2594129A (en) | Method of preparing surfaces for tinning | |
US3201293A (en) | Coated silicon iron sheet stock | |
US2529373A (en) | Treating silicon steel | |
JP5664286B2 (en) | Method for producing high silicon steel sheet |