Treatment Process
A method of conditioning an organic substrate is described The method involves heating the substrate using RF energy under desired pressure conditions in a constrained environment At a desired time point, the pressure is rapidly reduced causing any water present in the substrate to rapidly boil and convert to steam.
1 . A method of conditioning a substrate, the method including the steps of:
a) subjecting the substrate to RF energy in a constrained environment for a time sufficient to heat at least part of the moisture contained in the substrate to a temperature of or above the boiling point of water at ambient pressure; and
b) reducing pressure in the constrained environment in a manner causing the moisture within the substrate to boil or evaporate.
2 . A method as claimed in claim 1 wherein the RF energy is at a frequency between about 10 and 100 MHz.
3 . A method as claimed in claim 2 wherein the RF energy is at a frequency between about 27 and 40 MHz.
4 . A method as claimed in claim 1 wherein the pressure in the constrained environment is above atmospheric.
5 . A method as claimed in claim 4 wherein the pressure is between approximately 0.5 psi and 40 psi.
6 . A method as claimed in claim 5 wherein the pressure is between approximately 3 psi and 30 psi.
7 . A method as claimed in claim 6 wherein the pressure is between approximately 6 psi and 25 psi.
8 . A method as claimed in claim 1 wherein the pressure in the constrained environment is at atmospheric pressure.
9 . A method as claimed in claim 1 wherein the temperature achieved within the substrate is between 100 and 130 C.
10 . A method as claimed in claim 1 wherein the pressure in the constrained environment is reduced by venting.
11 . A method as claimed in claim 1 wherein the pressure is reduced by applying or producing a vacuum.
12 . A method as claimed in claim 1 wherein the pressure is reduced by a combination of venting and applying or producing a vacuum.
13 . A method as claimed in claim 1 wherein the substrate is a lignocellulosic material.
14 . A method as claimed in claim 13 wherein the substrate is wood.
15 . A method as claimed in claim 13 wherein the lignocellulosic material has a moisture content of more than 60% based on dry weight of the material.
16 . A method as claimed in claim 15 wherein the moisture content is greater than 100% based on dry weight of the material.
17 . A method as claimed in claim 15 wherein the moisture content is less than 30% based on dry weight of the material.
18 . A method as claimed in claim 1 wherein the method further comprises the step of storing the substrate to allow the temperature and moisture in the substrate to equilibrate.
19 . A method as claimed in claim 1 wherein the substrate is concurrently or subsequently impregnated with a composition.
20 . A method as claimed in claim 19 wherein the composition is an aqueous solution that contains polar and/or non polar solvents, pesticidal or preservative components, and/or polymeric or pre-polymeric components.
21 . A method as claimed in claim 19 wherein the composition contains a volatile pesticidal or preservative component and/or pre-polymeric component.
22 . A conditioning method comprising at least the steps of:
a) subjecting the substrate to RF energy in a constrained environment at substantially ambient pressure for a time sufficient to heat at least part of the moisture contained in the substrate to a temperature below the boiling point of water at ambient pressure; and
b) reducing pressure in the constrained environment by applying or producing a vacuum in a manner causing the moisture within the substrate to boil or evaporate.
23 . A conditioning method comprising at least the steps of:
a) subjecting the substrate to RF energy in a constrained environment for a time sufficient to heat at least part of the moisture contained in the substrate to a temperature of or above the boiling point of water at ambient pressure;
b) incorporating into the void surrounding the substrate in the constrained environment, a composition which may impart sterilisation, preservative, or property modifying aspects; and
c) reducing pressure in the constrained environment to allow the moisture within the substrate to boil and/or evaporate.
24 . A substrate that has been conditioned according to a method of claim 1 .
25 . A substrate as claimed in claim 24 wherein the substrate is a lignocellulosic material or wood.
26 . (canceled)
27 . A substrate that has been conditioned according to a method of claim 22 .
28 . A substrate that has been conditioned according to a method of claim 23 .
29 . A substrate as claimed in claim 27 wherein the substrate is a lignocellulosic material or wood.
30 . A substrate as claimed in claim 28 wherein the substrate is a lignocellulosic material or wood.