Now, the pre-drying process begins. In a vacuum, a gentle and controlled heating process reduces the moisture content of the paper. This makes the paper particularly absorbent for the impregnation step that comes next.
Finally, the chamber is filled with a non-aqueous treatment solution. The solution is made up of magnesium and titanium alcoholates (METE30) dissolved in hexamethylene disiloxane (HMDO). The treatment solution is non-toxic, environmentally friendly, and compatible with all books and archival materials. During the approximately 20 minute impregnation period, the vacuum ensures that the treatment solution penetrates the paper very evenly and completely. This transfers the neutralising agents into the paper.
Once the treatment solution is drained from the chamber, a number of rinse and drying cycles take place. In the process, the solvents evaporate out of the paper in a vacuum. The condensate is recycled. The deacidifying substances remain in the paper.