Abstract: A lumber production machine and method for processing lumber uses a pressure vessel that can accommodate untreated lumber and an injection pipe disposed in the pressure vessel that is capable of injecting saturated steam into the pressure vessel. A pressure gauge is operatively coupled to pressure vessel to determine the pressure inside the pressure vessel. There is a mechanism for setting a minimum and maximum pressure inside the pressure vessel. Solenoid valves control injection of saturated steam from the injection pipe into the interior of the pressure vessel. A controller opens the solenoid valves when the minimum pressure is reached and closes the solenoid valve when the maximum pressure is reached. The method includes pressurizing and heating the lumber products with saturated steam by varying the pressure to achieve a uniform temperature inside the lumber.

Abstract: A three step process to season lumber to reduce cracks in the lumber and reduce warping of the lumber. In a first step, the lumber is piled up into a pressure vessel for seasoning. The vessel is charged with saturated steam, the pressure of which fluctuates within the pressure vessel. This is done to enable any contained water within the vessels capillary tubes and cell cavities to evaporate at the same rate. Thereafter, as a second step the lumber is taken out of the pressure vessel in order to allow free water to evaporate from the lumber. The lumber in a third step is placed into the pressure vessel again and charged by a super saturated steam by using a flow of super saturated steam until remaining water is evaporated, thus forming lumber that is seasoned.