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Deacidification treatment

I will explain a series of work in the factory.


Registration work --Entry-

When the materials arrive at the factory, each barcode is first registered in the management database (Bookkeeper Tracking System) originally developed by Preservation Technologies LP (PTLP). At the same time, while inspecting the materials one by one, record their condition, accessories, processing method, etc.

If vulnerable parts such as page tears or deterioration of the binding structure are found in the target material, protect the page by wrapping a paper band to prevent the damage from spreading during processing.

The information in each of these materials is shared on the network within the factory to ensure high safety. A document-friendly human check is a feature of the bookkeeper deacidification process.

Deacidification treatment --Treating-

For deacidification treatment of well-bound books such as books, use a special holder and immerse it in the bookkeeper deacidification treatment solution for about 30 to 40 minutes. During that time, the holder slowly moves up and down. This creates a gentle stream of water that spreads the treatment solution to every corner.

At the end of the process, the liquid is drained and the material is transferred to a drying tank. After that, the treatment liquid remaining on this paper is completely vaporized for about 3 hours. The treated liquid that has become gas is collected by a dedicated device and reused.


Materials that cannot be machined, such as large maps and materials that are folded in multiple layers, are processed by hand spray.

The hand spray process has the same effect as the machine process. In the hand spray treatment, deacidification treatment is carried out by carefully spraying the liquid agent on each document.

Hand Spray-Hand Spray-

Cleaning work --Wiping -

Magnesium oxide, which is a deacidifying agent, may remain excessively on the cover, fold-out page, coated paper, etc. after processing. Carefully wipe off such areas one by one with a special cloth. Bookkeeper deacidification can also be used for easy cleaning of materials.


Inspection / packing work --Repacking -

After the work up to wiping is completed, the barcode of the material is reloaded into the management database Bookkeeper Tracking System, and the ordered list stored in the container when arriving at the factory is output.

Finally, check the condition of the materials, accessories, etc. again, and store each material in the container in the original order according to the list.

Also, if you wish, you can put a deacidification proof sticker on the back cover, or make a white spot on the back cover with a water-based pen. This is convenient because you can see at a glance that it has been deacidified. Stickers and white spots on the spine are also used by the Library of Congress.

Quality Control-Quality Control-

In the case of the bookkeeper deacidification treatment, it becomes a little powdery after the treatment, but it is not visible whether the necessary treatment has been applied. Therefore, test paper (quality control test paper piece) is inserted into the material at a fixed ratio (about 10%) and deacidified together with the paper material. After that, the test paper is removed and the pH and alkali reserve (alkali residue) are measured to observe the accuracy of the treatment and control the quality.


The above is the flow of the bookkeeper deacidification process.

We would appreciate it if you could understand our deacidification treatment technology.

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