US4207129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of conductive or semi-conductive elements by means of a continuous pultrusion process
Assignee: Honeywell UOP LLC
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Filing: 1979-04-05
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Granted: 1980-06-10
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Expires: 1999-04-05
Abstract
Abstract Conductive or semi-conductive elements which may be utilized as heating elements are manufactured in a continuous process utilizing a method known as pultrusion. The elements are prepared by forming semi-cured sheets comprising a support containing a mixture of a conductive or semi-conductive powder and a resin. The semi-cured sheets are fitted with conductive buss bars to form a conductive or semi-conductive element which is thereafter encapsulated in a glass roving-resin mixture to form the desired element. This element is then pulled through a heated die to effect the desired physical shape and thereafter may be cut to the desired size.
Inventors
- 👤 Thomas D. Tadewald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:35
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; B; B29; B29C; B29C70/00; B29C70/02; B29C70/021; B29C70/025; B29C70/028; B29C70/04; B29C70/28; B29C70/40; B29C70/50; B29C70/52; B29C70/525; B29C70/88; B29C70/882; B29K; B29K2061/00; B29K2061/04; B29K2067/00; B29K2067/06; B29K2313/00; B29K2705/00; B29K2705/08; B29K2711/00; B29K2711/12; B29K2995/00; B29K2995/0003; B29K2995/0005
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
195 words
A method for the continuous pultrusion of a shaped conductive or semi-conductive element which comprises the steps of: (a) admixing at least one conductive or semi-conductive powder possessing a conductivity at ambient temperature of from about 10 -8 to about 10 2 inverse ohm centimeters with a thermosetting polymeric resin; (b) applying said admixture to a support material to form a sheet; (c) placing conductive buss bars in juxtaposition between at least two of said sheets to form a conductive or semi-conductive element; (d) subjecting said element to a B-stage cure at a temperature in the range of from about ambient to about 400° F. to effect the formation of a semi-cured element; (e) reinforcing said element by adding thereto at least one layer of glass rovings; (f) encapsulating the reinforced element by passing said element through a bath of encapsulating thermoplastic or thermosetting resin; (g) pulling said encapsulated conductive or semi-conductive element through a heated die possessing a temperature gradient within said die of from about 100° to about 400° F. to effect the desired physical shape of said encapsulated conductive or semi-conductive element; and (h) recovering said shaped encapsulated conductive or semi-conductive element.
Claim 2
Independent Claim
195 words
A method for the continuous pultrusion of a shaped conductive or semi-conductive element which comprises the steps of: (a) admixing at least one conductive or semi-conductive powder possessing a conductivity at ambient temperature of from about 10 -8 to about 10 2 inverse ohm centimeters with a thermosetting polymeric resin; (b) applying said admixture to a support material to form a sheet; (c) placing conductive buss bars in juxtaposition between at least two of said sheets to form a conductive or semi-conductive element; (d) subjecting said element to a B-stage cure at a temperature in the range of from about ambient to about 400° F. to effect the formation of a semi-cured element; (e) reinforcing said element by adding thereto at least one layer of glass rovings; (f) encapsulating the reinforced element by passing said element through a bath of encapsulating thermoplastic or thermosetting resin; (g) pulling said encapsulated conductive or semi-conductive element through a heated die possessing a temperature gradient within said die of from about 100° to about 400° F. to effect the desired physical shape of said encapsulated conductive or semi-conductive element; and (h) recovering said shaped encapsulated conductive or semi-conductive element.
Claim 3
Dependent Claim
16 words
The method as set forth in claim 1 in which said conductive powder is acetylene black.
Claim 4
Dependent Claim
46 words
The method as set forth in claim 1 in which said semi-conductive powder possessing a conductivity of from 10 -8 to 10 2 inverse ohm centimeters is a high surface area inorganic oxide containing at least a monolayer of a carbonaceous pyropolymer on the surface thereof.
Claim 5
Dependent Claim
17 words
The method as set forth in claim 1 in which said thermosetting resin is a phenolic resin.
Claim 6
Dependent Claim
17 words
The method as set forth in claim 1 in which said thermosetting resin is an epoxy resin.
Claim 7
Dependent Claim
18 words
The method as set forth in claim 1 in which said conductive buss bar is a copper strip.
Claim 8
Dependent Claim
16 words
The method as set forth in claim 1 in which said support material is a paper.
Claim 9
Dependent Claim
17 words
The method as set forth in claim 7 in which said paper is a cotton linter paper.
Claim 10
Dependent Claim
17 words
The method as set forth in claim 1 in which said support material is a woven fabric.
Claim 11
Dependent Claim
15 words
The method as set forth in claim 9 in which said woven fabric is canvas.
Claim 12
Dependent Claim
18 words
The method as set forth in claim 1 in which said encapsulating resin is a polyester thermoplastic resin.
Claim 13
Dependent Claim
18 words
The method as set forth in claim 1 in which said encapsulating thermosetting resin is an epoxy resin.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |