US3830666A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Insulation application
Assignee: United States Department of the Army
•
Filing: 1973-06-12
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Granted: 1974-08-20
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Expires: 1993-06-12
Abstract
Abstract Disclosed is a method for applying and curing thermo insulation to an aluminum substructure, and particularly, to an elliptical cone shaped aluminum substructure. The method comprises curing and bonding a thin covering of insulation to the aluminum substructure by a one step curing procedure. The insulation thickness is in the range of about 0.0600 inches. The insulation which is comprised of epoxy-phenolic film adhesive and silica fabric-phenolic resin is cured under a predetermined amount of heat and pressure for a predetermined amount of time to yield a cured and bonded insulation capable of withstanding extreme temperature and aerodynamic shear environment.
Inventors
- 👤 F Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:45
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/12; B29; B29C; B29C63/00; B32B27/32; B32B27/322; B64; B64G; B64G1/00; B64G1/22; B64G1/52; B64G1/58; B32B2262/00; B32B2262/10; B32B2262/101; B32B2307/00; B32B2307/30; B32B2307/304; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31515; Y10T428/31522; Y10T442/00; Y10T442/10; Y10T442/102; Y10T442/133; Y10T442/138
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
112 words
The method as set forth in claim 1 wherein the inert gas employed for purging and pressurizing during said cure cycle is nitrogen gas; predetermined pressure for said cure cycle is about 50 + or - 5 psi; said predetermined temperature for said cure cycle is 290*F + or - 10*F which is reached in a predetermined minimum time of about 30 minutes, said predetermined temperature being maintained for said predetermined period of time of about 3 hours + or - 15 minutes; and said cooling under pressure is accomplished to a predetermined temperature value of about 100*F with the predetermined cooling rate being about 5*F per about 30 minutes time interval.
Claim 2
Dependent Claim
20 words
Connect the thermocouple leads, draw a full vacuum (20 inches of mercury minimum) and check for and seal all leaks.
Claim 3
Dependent Claim
54 words
The method as set forth in claim 1 wherein said alkyl ketone solvent is methyl ethyl ketone and wherein said primer is air dried at ambient temperature for about 30 minutes followed by an exposure for a predetermined period of time of about 1 hour and at a predetermined temperature exposure of about 180*F.
Claim 4
Dependent Claim
16 words
Pressurize the autoclave to 50 + or - 5 psi maintaining full vacuum on the assembly.
Claim 5
Dependent Claim
25 words
The method as set forth in claim 1 wherein said first partial vacuum is in the range of about 2 to 6 inches of mercury.
Claim 6
Dependent Claim
34 words
Raise the bond line temperature to 290* + or - 10*F in a minimum time of 30 minutes and maintain at 290* + or - 10*F for 3 hours + or - 15 minutes.
Claim 7
Dependent Claim
20 words
The method as set forth in claim 1 wherein said second partial vacuum is about 20 inches of mercury minimum.
Claim 8
Dependent Claim
106 words
Cool the bonded part under pressure to 100*F at a rate of 5*F per 30 minutes before removing from the autoclave. After removing the cured insulated vacuum-bagged part from the autoclave, remove the vacuum bag, bleeder cloth and masking tape from the part. The part is then rough trimmed by removing the excess high silica fabric on the aft end of the part. The part is then removed from the tool, and machining, as required, of the high silica fabric is accomplished to the dimensions required. EXAMPLE II Insulating a Yaw Fin of a Flight Vehicle 1-6. Follow same procedure as steps 1-6 of Example I.
Claim 9
Dependent Claim
31 words
The method as set forth in claim 1 wherein said partial vacuum drawn on said vacuum bag and contents is a partial vacuum of at least about 20 inches of mercury.
Claim 10
Dependent Claim
53 words
Remove the separator film from one side of the adhesive film, and apply the exposed surface of the adhesive film to the primed surface of the fin allowing the adhesive film to extend onto the Teflon tape approximately 1 inch at the aft end and 0.19 INCHES along the base of the fin.
Claim 11
Dependent Claim
34 words
Heat tack the adhesive film in place using a heating iron over a polytetrafluoroethylene separation sheet. At no time shall the adhesive film be exposed to more than 210*F for more than 60 seconds.
Claim 12
Dependent Claim
11 words
Remove the separator film from the surface of the adhesive film.
Claim 13
Dependent Claim
35 words
Locate the high silica fabric on the adhesive. Heat tack in place if necessary. NOTE: Position the longitudinal or warp direction of the material on the centerline of the structure with the warp face up.
Claim 14
Dependent Claim
19 words
Embed thermocouples under the excess high silica fabric around the edge as necessary to monitor the bond line temperature.
Claim 15
Dependent Claim
25 words
Apply one layer of release fabric wrinkle-free and without seams over the high silica fabric and hold it in place with high temperature masking tape.
Claim 16
Dependent Claim
44 words
Apply six layers of glass cloth wrinkle-free and with no seams over the high silica fabric area but with the edges extending beyond the high silica fabric by approximately 4 inches. Stretch the cloth tight and hold in place with high temperature masking tape.
Claim 17
Dependent Claim
44 words
Cover the remaining exposed adhesive film with tailored pieces of high silica fabric oriented the same as the previously applied fabric making a minimum gap butt joint without a selvage edge, heat tack in place, and trim to the edge of the adhesive film.
Claim 18
Dependent Claim
18 words
Cover the assembly with a plastic vacuum bag and seal to the tool with extruded vacuum bag sealant.
Claim 19
Dependent Claim
29 words
Attach vacuum hose fittings and vacuum gauge fittings to the vacuum bag in a manner to insure direct contact with the bleeder cloth extending beyond the high silica fabric.
Claim 20
Dependent Claim
19 words
Embed thermocouples under the excess high silica fabric around the edge as necessary to monitor the bond line temperature.
Claim 21
Dependent Claim
25 words
Apply one layer of release fabric wrinkle-free and without seams over the high silica fabric and hold it in place with high temperature masking tape.
Claim 22
Dependent Claim
68 words
Apply a vacuum of 2 to 6 inches of mercury, smoothing the bag and the bleeder material over the assembly. After the vacuum bag has been smoothed over the assembly, apply full vacuum pressure (20 inches of mercury minimum) and check for and seal all leaks in preparation for the cure cycle. The cure cycle procedure used for EXAMPLE I is also used for EXAMPLE II. I claim:
Claim 23
Dependent Claim
44 words
Apply six layers of glass cloth wrinkle-free and with no seams over the high silica fabric area but with the edges extending beyond the high silica fabric by approximately 4 inches. Stretch the cloth tight and hold in place with high temperature masking tape.
Claim 24
Dependent Claim
18 words
Cover the assembly with a plastic vacuum bag and seal to the tool with extruded vacuum bag sealant.
Claim 25
Dependent Claim
29 words
Attach vacuum hose fittings and vacuum gauge fittings to the vacuum bag in a manner to insure direct contact with the bleeder cloth extending beyond the high silica fabric.
Claim 26
Dependent Claim
80 words
Apply a vacuum of 2 to 6 inches of mercury, smoothing the bag and the bleeder material over the assembly. After the vacuum bag has been smoothed over the assembly, apply full vacuum pressure (20 inches of mercury minimum) and check for and seal all leaks in preparation for the cure cycle. The cure cycle is described below under the heading cure cycle and is substantially the same as previously described except additional control limits are set forth. CURE CYCLE
References Cited (Backward Citations)
US3616140A
Cited
US3603260A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |