US4548861A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Foam rigidizing process and products produced therewith
Assignee: Boeing Co
•
Filing: 1983-09-29
•
Granted: 1985-10-22
•
Expires: 2003-09-29
Abstract
Abstract A composite, rigid, structural, foam panel (11) comprising: (i) a flexible, non-structural, open cell reticulated or semi-reticulated, foam sheet (10); and (ii), an essentially closed cell resinous foam formed from a flowable, foamable material (12); and, wherein the open cell non-structural foam sheet (10) and the essentially closed cell foam are each coextensive with the volume of spaced defined by the panel (11). In a preferred embodiment of the invention, the flexible, non-structural, open cell reticulated or semi-reticulated foam sheet (10) comprises an electromagnetic wave absorber and, consequently, the essentially closed cell rigid structural panel (11) produced comprises a rigid, structural electromagnetic wave absorber. The rigid panels and/or absorbers (11) of the present invention are preferably formed of urethane-like materials and in a process embodying the invention wherein: a flowable, foamable, resinous material (12) composed of Components "A" and "B" and a suitable cream are proportioned to form a panel (11) of the desired shape; the Components are thoroughly stirred, and introduced into the bottom of a preheated, vented mold (15) having suitable vents (19); the open cell flexible foam sheet (10), precut to the desired size, is inserted into the mold (15) on top of the flowable, foamable, resinous material (12); the lid (18) of the mold (15) is closed and clamped in place; and, the reactive Components "A" and "B" are allowed to foam and expand in an exothermic reaction, whereby the expanding material (12) is forced into, entirely through, and entirely throughout the open cell foam sheet (10) with excess material (12) escaping from the mold (15) through the vents (19). After curing at room temperature for at least two hours, the panel (11) is demolded and trimmed as required.
Inventors
- 👤 John M. Barnes
- 👤 Robert G. Haley
- 👤 George E. Trepus, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:54
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/56; B29C44/5618; C; C08; C08J; C08J9/00; C08J9/36; C08J9/40; C08J9/42; C08J2205/00; C08J2205/04; C08J2205/05; C08J2475/00; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/24996; Y10T428/249986; Y10T428/249994; Y10T428/249999
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
252 words
The method of rigidizing a non-structural, flexible, open cell foam sheet comprising the steps of: (a) forming a flowable foamable resinous material characterized by its ability to produce a rigid structural element when foamed and cured; (b) placing the flowable foamable resinous material in a heated vented mold defining a given predetermined volume of space; (c) positioning a non-structural, flexible, open cell foam sheet within the heated vented mold in face-to-face relation with the flowable foamable resinous material and wherein the non-structural, flexible, open cell foam sheet is in the non-compressed state and essentially fills the given predetermined volume of space within the mold; (d) closing the heated vented mold and permitting the flowable foamable resinous material to expand and form in an exothermic reaction whereby the heat and pressure generated cause the flowable foamable resinous material to expand into and uniformly through and throughout the non-structural, flexible, open cell, non-compressed foam sheet without compressing and/or damaging the cellular walls of the open cell non-compressed foam sheet and with excess foamed resinous material escaping from the vented mold through the vents therein; and, (e) curing the uniformly impregnated open cell foam sheet and the expanded foamed resinous material impregnated therein to form a composite structural panel comprising: (i) a non-structural, flexible, open cell foam sheet having the same dimensions as when initially positioned within the mold in step (c); and (ii), a rigid essentially closed cell structural foam uniformly dispersed throughout the interstices of the non-structural, flexible, open cell, non-compressed foam sheet.
Claim 2
Independent Claim
252 words
The method of rigidizing a non-structural, flexible, open cell foam sheet comprising the steps of: (a) forming a flowable foamable resinous material characterized by its ability to produce a rigid structural element when foamed and cured; (b) placing the flowable foamable resinous material in a heated vented mold defining a given predetermined volume of space; (c) positioning a non-structural, flexible, open cell foam sheet within the heated vented mold in face-to-face relation with the flowable foamable resinous material and wherein the non-structural, flexible, open cell foam sheet is in the non-compressed state and essentially fills the given predetermined volume of space within the mold; (d) closing the heated vented mold and permitting the flowable foamable resinous material to expand and form in an exothermic reaction whereby the heat and pressure generated cause the flowable foamable resinous material to expand into and uniformly through and throughout the non-structural, flexible, open cell, non-compressed foam sheet without compressing and/or damaging the cellular walls of the open cell non-compressed foam sheet and with excess foamed resinous material escaping from the vented mold through the vents therein; and, (e) curing the uniformly impregnated open cell foam sheet and the expanded foamed resinous material impregnated therein to form a composite structural panel comprising: (i) a non-structural, flexible, open cell foam sheet having the same dimensions as when initially positioned within the mold in step (c); and (ii), a rigid essentially closed cell structural foam uniformly dispersed throughout the interstices of the non-structural, flexible, open cell, non-compressed foam sheet.
Claim 3
Independent Claim
263 words
The method of rigidizing a non-structural, flexible, open cell foam sheet comprising the steps of: (a) forming a flowable foamable resinous material characterized by its ability to produce a rigid structural element when foamed and cured; (b) placing the flowable foamable resinous material in a vented mold defining a given predetermined volume of space; (c) positioning a non-structural, flexible, open cell foam sheet within the vented mold in face-to-face relation with the flowable foamable resinous material and wherein the non-structural, flexible, open cell foam sheet is in the non-compressed state and essentially fills the given predetermined volume of space within the mold; (d) closing the vented mold; (e) heating the closed vented mold and the flowable foamable resinous material therein to cause the flowable foamable resinous material to expand and foam in an exothermic reaction whereby the heat and pressure generated cause the flowable foamable resinous material to expand into and uniformly through and throughout the non-structural, flexible, open cell, non-compressed foam sheet without compressing and/or damaging the cellular walls of the open cell non-compressed foam sheet and with excess foamed resinous material escaping from the heated vented mold through the vents therein; and, (f) curing the uniformly impregnated open cell foam sheet and the expanded foamed resinous material impregnated therein to form a composite structure panel comprising: (i) a non-structural, flexible, open cell foam sheet having the same dimensions as when initially positioned within the mold in step (c); and (ii), a rigid essentially closed cell structure foam uniformly dispersed throughout the interstices of the non-structural, flexible, open cell, non-compressed foam sheet.
Claim 4
Independent Claim
263 words
The method of rigidizing a non-structural, flexible, open cell foam sheet comprising the steps of: (a) forming a flowable foamable resinous material characterized by its ability to produce a rigid structural element when foamed and cured; (b) placing the flowable foamable resinous material in a vented mold defining a given predetermined volume of space; (c) positioning a non-structural, flexible, open cell foam sheet within the vented mold in face-to-face relation with the flowable foamable resinous material and wherein the non-structural, flexible, open cell foam sheet is in the non-compressed state and essentially fills the given predetermined volume of space within the mold; (d) closing the vented mold; (e) heating the closed vented mold and the flowable foamable resinous material therein to cause the flowable foamable resinous material to expand and foam in an exothermic reaction whereby the heat and pressure generated cause the flowable foamable resinous material to expand into and uniformly through and throughout the non-structural, flexible, open cell, non-compressed foam sheet without compressing and/or damaging the cellular walls of the open cell non-compressed foam sheet and with excess foamed resinous material escaping from the heated vented mold through the vents therein; and, (f) curing the uniformly impregnated open cell foam sheet and the expanded foamed resinous material impregnated therein to form a composite structure panel comprising: (i) a non-structural, flexible, open cell foam sheet having the same dimensions as when initially positioned within the mold in step (c); and (ii), a rigid essentially closed cell structure foam uniformly dispersed throughout the interstices of the non-structural, flexible, open cell, non-compressed foam sheet.
Claim 5
Dependent Claim
16 words
The rigid composite structural panel formed by the method set forth in claims 1 or 2.
Claim 6
Independent Claim
51 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the non-structural, flexible, open cell foam sheet comprises a matrix-like support for a multiplicity of dielectric and/or magnetic particles, and the rigidized, composite, structural panel formed is an electromagnetic wave absorber.
Claim 7
Dependent Claim
15 words
The rigidized structural electromagnetic wave absorber formed by the method set forth in claim 4.
Claim 8
Independent Claim
30 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the open cell foam sheet is formed of polyurethane material.
Claim 9
Independent Claim
28 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the flowable foamable resinous material comprises polyurethane material.
Claim 10
Independent Claim
37 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the open cell foam sheet and the flowable foamable resinous material are each formed of polyurethane material.
Claim 11
Independent Claim
39 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the mold is heated to a temperature in the range of from about 85° F. to about 100° F.
Claim 12
Independent Claim
35 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the composite panel produced is cured at room temperature for a minimum of two hours.
Claim 13
Independent Claim
48 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the non-structural, flexible, open cell foam sheet and the expanded foamed resinous material are each coextensive with the volume of space defined by the rigid structural panel produced.
Claim 14
Independent Claim
55 words
The method of rigidizing a non-structural, flexible, open cell foam sheet as set forth in claims 1 or 2 wherein the rigid structural panel formed is machined to remove ridges, burrs and/or projections thereon in the regions of the mold vents to provide a smooth rigid structural panel capable of functioning as a load-bearing element.
Claim 15
Dependent Claim
70 words
A lightweight, rigid, structural panel comprising, in combination, a non-structural, flexible, open cell, non-compressed foam sheet which occupies a given predetermined volume of space and an essentially closed cell structural foam uniformly distributed throughout the interstices of said open cell non-structural, flexible, non-compressed foam sheet so as to form a structural panel occupying essentially the same given predetermined volume of space as said non-structural, flexible, open cell, non-compressed foam sheet.
Claim 16
Dependent Claim
70 words
A lightweight, rigid, structural panel comprising, in combination, a non-structural, flexible, open cell, non-compressed foam sheet which occupies a given predetermined volume of space and an essentially closed cell structural foam uniformly distributed throughout the interstices of said open cell non-structural, flexible, non-compressed foam sheet so as to form a structural panel occupying essentially the same given predetermined volume of space as said non-structural, flexible, open cell, non-compressed foam sheet.
Claim 17
Dependent Claim
22 words
A lightweight, rigid, structural panel as set forth in claim 13, wherein said open cell foam sheet is formed of polyurethane material.
Claim 18
Dependent Claim
23 words
A lightweight, rigid, structural panel as set fortth in claim 13, wherein said essentially closed cell structural foam is formed of polyurethane material.
Claim 19
Dependent Claim
30 words
A lightweight, rigid, structural panel as set forth in claim 13, wherein said open cell foamed sheet and said essentially closed cell structural foam are each formed of polyurethane material.
Claim 20
Dependent Claim
39 words
A lightweight, rigid, structural panel as set forth in claim 13, wherein said non-structural, flexible, open cell, non-compressed foam sheet and said essentially closed cell structural foam are each coextensive with the volume of spaced defined by said panel.
Claim 21
Dependent Claim
111 words
A lightweight, rigid, electromagnetic wave absorber comprising, in combination: (a) a non-structural, flexible, open cell foam sheet which occupies a given predetermined volume of space and which is in the non-compressed state, said open cell foam sheet having a multiplicity of dielectric and/or magnetic particles dispersed throughout the open cell structure of said foam sheet which forms a matrix-like support therefore; and, (b) an essentially closed cell structural foam uniformly distributed throughout the interstices of said non-structural, flexible, open cell, non-compressed foam sheet so as to form a lightweight, rigid, electromagnetic wave absorber occupying essentially the same given predetermined volume of space as said non-structural, flexible, open cell, non-compressed foam sheet.
Claim 22
Dependent Claim
111 words
A lightweight, rigid, electromagnetic wave absorber comprising, in combination: (a) a non-structural, flexible, open cell foam sheet which occupies a given predetermined volume of space and which is in the non-compressed state, said open cell foam sheet having a multiplicity of dielectric and/or magnetic particles dispersed throughout the open cell structure of said foam sheet which forms a matrix-like support therefore; and, (b) an essentially closed cell structural foam uniformly distributed throughout the interstices of said non-structural, flexible, open cell, non-compressed foam sheet so as to form a lightweight, rigid, electromagnetic wave absorber occupying essentially the same given predetermined volume of space as said non-structural, flexible, open cell, non-compressed foam sheet.
Claim 23
Dependent Claim
23 words
A lightweight, rigid, electromagnetic wave absorber as set forth in claim 18, wherein said open cell foam sheet is formed of polyurethane material.
Claim 24
Dependent Claim
24 words
A lightweight, rigid, electromagnetic wave absorber as set forth in claim 18, wherein said essentially closed cell structural foam is formed of polyurethane material.
Claim 25
Dependent Claim
33 words
A lightweight, rigid, electromagnetic wave absorber as set forth in claim 18, wherein said non-structural, flexible, open cell foam sheet and said essentially closec cell structural foam are each formed of polyurethane material.
Claim 26
Dependent Claim
42 words
A lightweight, rigid, electromagnetic wave absorber as set forth in claim 18, wherein said non-structural, flexible, open cell, non-compressed foam sheet and said essentially closed cell structural foam are each coextensive with the volume of space defined by said electromagnetic wave absorber.
References Cited (Backward Citations)
US2194036A
Cited
US2770864A
Cited
US3086247A
Cited
US3094433A
Cited
US3047888A
Cited
US3193598A
Cited
US3193441A
Cited
US3464872A
Cited
US3341640A
Cited
US3353994A
Cited
GB1076130A
Cited
US3382302A
Cited
DE1808349A1
Cited
US3915783A
Cited
US3989781A
Cited
US3917547A
Cited
US3993608A
Cited
US3996654A
Cited
US3944704A
Cited
US4082704A
Cited
US4239564A
Cited
US4171410A
Cited
US4208696A
Cited
US4258100A
Cited
US4362778A
Cited
US4419261A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-21 | 1989-04-22 | 1989-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-21 | 1993-04-22 | 1993-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-21 | 1997-04-22 | 1997-10-22 | $7700.00 | Window Closed / Lapsed |