Cellulosic and lignocellulosic structural materials and methods and systems for manufacturing such materials
Methods of treating wood and wood products include irradiating untreated wood having a first molecular weight with ionizing radiation to cause an increase in the molecular weight of a cellulosic component of the wood to a second, relatively higher molecular weight.
1. A method of treating wood, the method comprising:
irradiating untreated wood having a first molecular weight with from about 0.25 to about 10 MRad of electron beam radiation, having an energy of about 2.5 to about 10 MeV, to increase the molecular weight of a cellulosic component of the wood to a second, relatively higher molecular weight at least about 10% higher than the first weight.
2. The method of claim 1 , wherein the dose of ionizing radiation is at a level of about 0.25 to about 2.5 MRad.
3. The method of claim 1 , further comprising quenching the irradiated wood.
4. The method of claim 3 , wherein quenching is performed in the presence of a gas selected to react with radicals present in the irradiated wood.
5. The method of claim 1 wherein the wood is in the form of sawn lumber or a finished wood product.
6. The method of claim 1 , wherein the increase in molecular weight is at least 50%.
7. The method of claim 1 wherein irradiating comprises irradiating multiple times.
8. The method of claim 1 wherein the wood has multiple sides and irradiating comprises irradiating more than one side of the wood.
9. The method of claim 1 wherein the wood is irradiated at a dose rate of at least 0.5 Mrad/s.
10. The method of claim 9 wherein the wood is irradiated at a dose rate of at least 1 Mrad/sec.