Preservation activities at the Joël‑Le‑Theule Technical Center consist of:
- restoration workshops
- reproduction/digitization workshops
- training activities (emergency plan)
- a mass deacidification unit
The Joël-le-Theule Technical Center, which is housed in an 18th century château, was set up to create backups of printed materials. Printed materials published from the 1870s onwards were printed on acidic paper and are deteriorating over time. The first priority is therefore to preserve the content of documents by means of a mass reproduction policy, as well as potentially treating the paper in order to slow the degradation process.
When workshops were established at the François-Mitterrand Library and the Bussy-Saint-Georges Technical Preservation Center, this site focused more on backing up documents from collections held at the Richelieu Library, the Opera Library and the Arsenal Library while continuing to work for subject departments based at the François-Mitterrand Library.
Various types of complementary process are used:
- restoration of sheet-type documents, bound documents and oversize posters
Specific to this site : mass desacidification and wax 213
- Mass desacidification unit
In order to neutralize acid in the paper, this site houses a desacidification unit.
Batches of 100 to 200 volumes are treated in a vacuum chamber where they are first dehydrated (paper moisture is brought back to 0,5%) before being immersed in an aqueous solution composed of freon (90%) and magnesium ethoxide under pressure. 25,000 to 30,000 volumes a year can be treated in the desacidification unit. This unit is open to other institutions.
- Wax 213
Developed by the Centre de recherche sur la conservation des collections (CRCC), a laboratory of CNRS, Wax 213 is manufactured under license and marketed by the Bibliothèque nationale de France. It is especially recommended for the care of leather bounds in good condition. It can be purchased at the BnF Commercial department.