US5123985A
Expired / Lapsed
US
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Vacuum bagging apparatus and method including a thermoplastic elastomer film vacuum bag
Assignee: Individual
•
Filing: 1990-04-12
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Granted: 1992-06-23
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Expires: 2010-04-12
Abstract
Abstract Thermoplastic elastomer film vacuum bags are provided which readily conform to the surface contour of the workpiece at low pressures without failure. The thermoplastic elastomer film can be made into thin films which are able to withstand higher pressures and temperatures than the prior art nylon films. The films can also withstand the presence of epoxide and phenolic resins during pressure and cure without degradation. Preferred thermoplastic elastomers are block copolymers such as Hytrel. The films are pliable and can be used with minimal or no pleating.
Inventors
- 👤 Patricia Evans
- 👤 David Evans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:37
CPC Classifications
B; B29; B29D; B29D7/00; B29D7/01; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/42; B29C70/44; B29C43/00; B29C43/02; B29C43/10; B29C43/12; B29K; B29K2823/00; B29K2825/00; B29K2867/00; B29K2869/00; B29K2871/00; B29K2875/00; B29K2877/00; B29K2879/00; B29K2879/08; B29K2883/00; B29K2896/00; B29K2896/04; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1028; Y10T156/103
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
86 words
A method for forming a workpiece comprising the steps of: placing the workpiece on an air-tight base; applying an impervious bag of a thermoplastic elastomer film over the workpiece and base, the film having a thickness of no greater than about 10 thousandths of an inch and a secant modulus of elasticity at 100% elongation of no greater than about 2500 psi at room temperatures; and applying a pressure differential across the film to cause the film to stretch and yield to conform to the workpiece.
Claim 2
Independent Claim
86 words
A method for forming a workpiece comprising the steps of: placing the workpiece on an air-tight base; applying an impervious bag of a thermoplastic elastomer film over the workpiece and base, the film having a thickness of no greater than about 10 thousandths of an inch and a secant modulus of elasticity at 100% elongation of no greater than about 2500 psi at room temperatures; and applying a pressure differential across the film to cause the film to stretch and yield to conform to the workpiece.
Claim 3
Independent Claim
87 words
A method for forming a workpiece comprising the steps of: placing the workpiece on an air-tight base; applying an impervious bag of a thermoplastic elastomer film over the workpiece and base; forming an air-tight seal around the workpiece between the film and base; and applying a pressure differential across the film to cause the film to stretch in a substantially elastic manner up to a yield stress and thereafter yield at substantially the yield stress up to at least about 400% elongation to conform to the workpiece.
Claim 4
Independent Claim
87 words
A method for forming a workpiece comprising the steps of: placing the workpiece on an air-tight base; applying an impervious bag of a thermoplastic elastomer film over the workpiece and base; forming an air-tight seal around the workpiece between the film and base; and applying a pressure differential across the film to cause the film to stretch in a substantially elastic manner up to a yield stress and thereafter yield at substantially the yield stress up to at least about 400% elongation to conform to the workpiece.
Claim 5
Dependent Claim
26 words
The method of claim 2, wherein the film stretches elastically to conform to the workpiece at a pressure differential of no greater than about 100 psi.
Claim 6
Dependent Claim
18 words
The method of claim 2, wherein the film stretches elastically up to about 100-200% elongation and thereafter yields.
Claim 7
Dependent Claim
40 words
The method of claim 2, wherein the film has a thickness of from about two to about five thousandths of an inch and stretches elastically to contact the workpiece at a pressure differential of no greater than about 100 psi.
Claim 8
Dependent Claim
37 words
The method of claim 2, adapted for curing at temperatures of up to about 350° F., wherein the film is a polyester/polyether block copolymer having a thickness of no greater than about three thousandths of an inch.
Claim 9
Dependent Claim
23 words
The method of claim 2, adapted for curing at of up to about 400° F., wherein the film is a copolyester block copolymer.
Claim 10
Dependent Claim
24 words
The method of claim 2, adapted for curing at temperatures of up to about 600° F., wherein the film is a polyimide/siloxane block copolymer.
Claim 11
Dependent Claim
102 words
An improved vacuum bagging apparatus comprising: a base for supporting a workpiece; an impervious bag positionable over the workpiece and attachable to the base; and means for applying a pressure differential across the bag causing the bag to exert substantially uniform pressure on the workpiece; wherein the bag comprises a thermoplastic elastomer film having a thickness of no greater than about 10 thousandths of an inch and a secant modulus of elasticity at 100% elongation of no greater than about 2500 psi at room temperature, wherein the film stretches and yields to conform to a workpiece when a pressure differential is applied.
Claim 12
Dependent Claim
102 words
An improved vacuum bagging apparatus comprising: a base for supporting a workpiece; an impervious bag positionable over the workpiece and attachable to the base; and means for applying a pressure differential across the bag causing the bag to exert substantially uniform pressure on the workpiece; wherein the bag comprises a thermoplastic elastomer film having a thickness of no greater than about 10 thousandths of an inch and a secant modulus of elasticity at 100% elongation of no greater than about 2500 psi at room temperature, wherein the film stretches and yields to conform to a workpiece when a pressure differential is applied.
Claim 13
Dependent Claim
38 words
The apparatus of claim 9, wherein the film exhibits a substantially elastic stretch up to a yield stress and thereafter yields at substantially the yield stress up to at least about 400% elongation to conform to the workpiece.
Claim 14
Dependent Claim
25 words
The apparatus of claim 9, wherein the film is stretchable to contact the workpiece at a pressure differential of no greater than about 100 psi.
Claim 15
Dependent Claim
22 words
The apparatus of claim 9, wherein the film has a thickness of from about 2 to about 5 thousandths of an inch.
Claim 16
Dependent Claim
29 words
The apparatus of claim 9, wherein the film has a melt temperature of at least about 400° F. and a Vicat softening temperature of at least about 350° F.
Claim 17
Dependent Claim
34 words
The apparatus of claim 9, wherein the film is selected from the group consisting of block copolymers or blends of polyester, polyether, polyamide, polyurethane, polyolefin, polystyrene, polyacrylic, polyvinyl, polycarbonate, polyimide, polysiloxane, and mixtures thereof.
Claim 18
Dependent Claim
43 words
The apparatus of claim 14, wherein the film is a block copolymer (ab) comprising segments a) selected from the group consisting of polyether, polyester, and mixtures thereof, joined by segments b) selected from the group consisting of polyester, polyurethane, polyamide, and mixtures thereof.
Claim 19
Dependent Claim
13 words
The apparatus of claim 15, wherein the film is a polyester/polyether block copolymer.
Claim 20
Dependent Claim
25 words
The apparatus of claim 16, wherein the copolymer has an apparent hardness of from about 40 and about 72 Shore D, according to ASTM D2246.
Claim 21
Dependent Claim
23 words
The apparatus of claim 16, wherein the film is a copolymer of polytetramethylene ether glycol and terephthalic acid, and butene-1,4-diol and terephthalic acid.
Claim 22
Dependent Claim
26 words
The apparatus of claim 16, wherein the film further includes an antioxidant to increase the resistance of the film to oxygen in the presence of heat.
Claim 23
Dependent Claim
54 words
The apparatus of claim 9, wherein the film comprises a blend of: a block copolymer having an apparent hardness of about 55 Shore D, according to ASTM D2240; a viscosity modifier to increase the melt viscosity; and an antioxidant modifier to increase the resistance of the film to oxygen in the presence of heat.
Claim 24
Dependent Claim
29 words
The apparatus of claim 20, wherein the viscosity modifier comprises another block copolymer having substantially the same physical properties but which has been modified to increase its melt viscosity.
Claim 25
Dependent Claim
13 words
The apparatus of claim 9, wherein the film comprises: a polyester/polyester block copolymer.
Claim 26
Dependent Claim
18 words
The apparatus of claim 22, wherein the film has a thickness of about 3 thousandths of an inch.
Claim 27
Dependent Claim
13 words
The apparatus of claim 9, wherein the film comprises: a polyimide/siloxane block copolymer.
Claim 28
Dependent Claim
90 words
An improved vacuum bagging apparatus comprising: a base for supporting a workpiece; an impervious bag positionable over the workpiece and attachable to the base; and means for applying a pressure differential across the bag causing the bag to exert substantially uniform pressure on the workpiece; wherein the bag comprises a thermoplastic elastomer film which upon application of a pressure differential exhibits a substantially elastic stretch up to a yield stress and thereafter yields at substantially the yield stress up to at least about 400% elongation to conform to the workpiece.
Claim 29
Dependent Claim
90 words
An improved vacuum bagging apparatus comprising: a base for supporting a workpiece; an impervious bag positionable over the workpiece and attachable to the base; and means for applying a pressure differential across the bag causing the bag to exert substantially uniform pressure on the workpiece; wherein the bag comprises a thermoplastic elastomer film which upon application of a pressure differential exhibits a substantially elastic stretch up to a yield stress and thereafter yields at substantially the yield stress up to at least about 400% elongation to conform to the workpiece.
Claim 30
Dependent Claim
119 words
A vacuum bagging assembly for forming a workpiece comprising: an air-tight base on which a workpiece is placed; a stretchable thermoplastic elastomer film as an impervious bag to be laid across the workpiece and held securely to the base, the film having a thickness of no greater than about 10 thousandths of an inch and a secant modulus of elasticity at 100% elongation of no greater than about 2500 psi at room temperature; a fastening means to secure and form a continuous air tight seal between the film and the base; and a means for applying a pressure differential across the film, wherein the film stretches and yields to conform to the workpiece when a pressure differential is applied.
Claim 31
Dependent Claim
119 words
A vacuum bagging assembly for forming a workpiece comprising: an air-tight base on which a workpiece is placed; a stretchable thermoplastic elastomer film as an impervious bag to be laid across the workpiece and held securely to the base, the film having a thickness of no greater than about 10 thousandths of an inch and a secant modulus of elasticity at 100% elongation of no greater than about 2500 psi at room temperature; a fastening means to secure and form a continuous air tight seal between the film and the base; and a means for applying a pressure differential across the film, wherein the film stretches and yields to conform to the workpiece when a pressure differential is applied.
References Cited (Backward Citations)
US5037599A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-23 | 1995-12-23 | 1996-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-23 | 1999-12-23 | 2000-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-23 | 2003-12-23 | 2004-06-23 | $7700.00 | Window Closed / Lapsed |