Oscillating pressure process

A process for the impregnation of wet timbers with moisture levels of over 80%. The oscillating pressure process was developed especially for the treatment of green spruce timbers.

In the oscillating pressure process, the treatment vessel is flooded with preservative solution without an initial vacuum. After an initial pressure phase of 30 to 60 minutes, the dynamic pressure oscillation phase begins. At short intervals, the pressure and vacuum phases alternate, changing abruptly from one to the other. This oscillating pressure phase last for at least 10 hours with a minimum of 160 cycles.

Besides the classic oscillating pressure process, there are several variations in use, such as the Hamburg process, in which the pressure phases alternate between high and atmospheric pressure. A vacuum is not used.