Microwave curing of alkaline phenolic resins in wood-resin compositions
First Claim
1. 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.
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Accused Products
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.
46 Citations
12 Claims
- 1. 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.
Specification