An economical pressure treatment process for reducing preservative intake.
As in other economical processes (Rueping process), the Lowry process requires no initial vacuum. Instead, the preservative solution is forced deep into the wood under high pressure. The air inside the wood then expends when the pressure is released, causing any excess preservative to be forced out of the wood.
In order to achieve the required preservative intake levels, solution concentration or aqueous preservatives must be increased accordingly.
The Lowry process is used as the first stage of the Royal process, for example.