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Frequently Asked Questions
The following are some commonly asked questions about the Bookkeeper Deacidification Process and their answers. If you have other questions, please contact us.
1. What is the Bookkeeper Deacidification Process?
The buffer materials are microscopic particles of an alkaline compound (magnesium oxide). The particles are dispersed and suspended in an inert liquid material (a blend of non-toxic fluorinated materials). This dispersion can be applied by dipping or spraying. In contact with paper, the alkaline particles attach and blend with the paper structure, and the inert liquid simply evaporates. Because the formula contains no water, the liquid does not cause the paper fibers to swell or make the paper “wet,” and it will not cockle or stiffen from the application.
The process does not require pretreatment drying or post-treatment off-gassing and reconditioning of the paper. In small batches, the materials to be treated are immersed in the treating bath, and gentle motions of the paper and liquid are used to help ensure uniform coverage. During this time, the treating bath is continuously circulated to filter loose dust and dirt from the books and to monitor and maintain the proper concentration of treating materials. Then the treating materials are drained, and the remaining liquid evaporates and is recovered in the process. Batches usually take about 2 hours total, and the moisture content of the paper is not affected by the treatment.
Materials are treated individually or in small batches to ensure quality control. The final pH of the paper following treatment depends heavily on the paper composition prior to treatment. The range of possible pH results is between 7 and 10, and typical results are in the range of 8.0 - 9.5. Sufficient alkaline material is added to the paper to provide a protective alkaline reserve. The typical reserve is equivalent to adding 1.5% by weight calcium carbonate, or 300 milliequivalents per kilogram.
Over the first few weeks following treatment, the magnesium oxide particles combine with moisture in the air to form magnesium hydroxide, also a non-toxic alkaline buffer. These buffer particles readily absorb and neutralize the acids in the paper. The material continues to absorb acid over the life of the paper. This is a permanent treatment that should not need to be repeated under normal storage conditions.
2. Is the Bookkeeper Deacidification Process effective?
3. How does the treatment work?
The acids in paper migrate freely. We see this effect when acidic paper damages adjacent, non-acidic materials. Alkaline buffered folders or boxes holding acidic papers can become acidic in just a few years time from this effect. Under normal storage conditions, acid reacts very slowly with cellulose fibers but very quickly with alkaline materials. The Bookkeeper process takes advantage of this difference in reaction rates to protect the paper. Within the structure of the paper, the acids migrate among the cellulose fibers where they are quickly absorbed and neutralized by the highly absorbent alkaline particles, long before they have time to react with and weaken the cellulose fibers.
4. What materials can be treated?
The treating process is very gentle, but the materials to be treated should be in stable condition and able to withstand careful handling. Materials in poor repair or too fragile to handle are usually not considered good candidates for this treatment.
5. Is it safe for photographs?
6. Is it safe for colors and inks?
In a few cases, the shade of a color may be affected by the change in pH from acid to alkaline. But even pH sensitive colors are often not affected unless the paper becomes wet with water or in very humid conditions. The Bookkeeper process should not be used on “blue prints” or other similar materials because these colors may be affected by raising the pH.
7. What about glossy or encapsulated materials?
The Bookkeeper process will provide limited benefits for coated paper materials. This type of paper will absorb less alkaline buffer and will usually have a light coating on the surface as well. The surface material can be removed by wiping, and the paper will retain some alkaline buffer.
8. Does it stop paper from yellowing?
9. Can raising the pH cause alkaline hydrolysis?
10. Is it hazardous in any way?
11. Is more testing planned?
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