US4018642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave curing of alkaline phenolic resins in wood-resin compositions
Assignee: Macmillan Bloedel Limburg NV
•
Filing: 1975-09-08
•
Granted: 1977-04-19
•
Expires: 1995-09-08
Abstract
Abstract Microwave energy applied to a wood-resin composition such as plywood is used to cure the resin in a very short time, as compared with a conventional hot press process, and yet avoids the arcing and tracking problem that results when R.F. dielectric heating is used to reduce cure time. Pressure is applied to the plywood or other article being made either simultaneously with the microwave energy or shortly after the lather has been applied.
Inventors
- 👤 Robert L. Pike
- 👤 Derek Barnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:57
CPC Classifications
B; B27; B27D; B27D1/00; B27D1/02; B27D1/025; H; H05; H05B; H05B6/00; H05B6/64; H05B6/80
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
104 words
A method for making a composite product from a composition comprising wood and a binder for said wood, said binder comprising an alkaline phenolic resin whose rate of cure is accelerated by the application of heat, said method comprising locating said composition in juxtaposition with respect to a waveguide such that microwaves propagating through said waveguide in the form of a travelling wave will propagate through said composition, propagating a microwave having a frequency of at least 100 MHz through said waveguide and said composition to heat said resin and accelerate its curing, and applying pressure to said composition before said resin has cured.
Claim 2
Independent Claim
104 words
A method for making a composite product from a composition comprising wood and a binder for said wood, said binder comprising an alkaline phenolic resin whose rate of cure is accelerated by the application of heat, said method comprising locating said composition in juxtaposition with respect to a waveguide such that microwaves propagating through said waveguide in the form of a travelling wave will propagate through said composition, propagating a microwave having a frequency of at least 100 MHz through said waveguide and said composition to heat said resin and accelerate its curing, and applying pressure to said composition before said resin has cured.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein said frequency is less than 10,000 MHz.
Claim 4
Dependent Claim
12 words
A method according to claim 2 wherein said frequency is 915 MHz.
Claim 5
Dependent Claim
12 words
A method according to claim 2 wherein said frequency is 2450 MHz.
Claim 6
Dependent Claim
25 words
A method according to claim 1 wherein said product is plywood and said wood is in the form of sheets laminated together by said resin.
Claim 7
Dependent Claim
27 words
A method according to claim 5 wherein said microwaves have an electric field vector that is substantially perpendicular to said sheets and the layers of resin therebetween.
Claim 8
Dependent Claim
26 words
A method according to claim 5 wherein said microwaves have an electric field that is substantially parallel to said sheets and the layers of resin therebetween.
Claim 9
Dependent Claim
12 words
A method according to claim 1 wherein said product is particle board.
Claim 10
Dependent Claim
12 words
A method according to claim 1 wherein said product is chip board.
Claim 11
Dependent Claim
12 words
A method according to claim 1 wherein said product is wafer board.
Claim 12
Dependent Claim
36 words
A method according to claim 1 wherein said wood is in the form of a bundle of fibres having top, bottom and side edges and said pressure is applied to said top, bottom and side edges.
Claim 13
Dependent Claim
20 words
A method according to claim 1 wherein said pressure is applied simultaneously with propagation of said microwave through said composition.
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) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |