CSC Booksaver®:
Solutions for Preserving Our Written Heritage

CSC Book Saver® has developed and patented a line of products and processes for the preservation of our bibliographic and documentary heritage.

The flexibility and modular design of our products’ preservation technologies facilitate adaptation to the specific needs of each archive and library.

The de-acidification of individual sheets of paper using an alkaline bath is a method that provides excellent results but is obviously impracticable as a method for collections of thousands of books and documents because of its cost and the time it would take. The alkaline-bath method can only be used on individual works of great value. The solution for archives and libraries involves a technology that makes it possible to quickly mass treat collections without having to remove the binding.

1. The solution to a Major Challenge
2. The Book Saver® Reagent
3. Work Procedures and Quality Control

The CSC Book Saver® technology is the solution to this major challenge because it provides for the simultaneous de-acidification and disinfection of more than 250,000 kg of books and documents a year without having to remove the binding by means of a fast, effective, low-cost method that can be used by any archive or library.

The Book Saver® process involves the use of a unit, where books and documents are placed without removing the binding, as well as a reagent that neutralizes the acidity without attacking the dyes. The simplification and automation of the project results in a drastic reduction in costs.

-The unit can be moved to archives and libraries. It is not necessary to ship books and documents, which saves on packaging, transport and insurance, while reducing the risk of accidents.

- The operation merely involves pre-selecting the material to be treated, loading it into and unloading it from the unit, the treatment itself, and airing the treated documents. During the pre-selection process, books that are highly deteriorated, have holes from insects and larvae, or are in an advanced state of degradation (pH below 3.5) are separated for manual restoration, if possible. The books and documents to be treated are placed on a tray in the unit without removing the binding. The most suitable programme is selected for the kind of paper and the automatic cycle is turned on.

- Once the cycle is completed, the operator takes the books out of the unit and allows them to air dry.

In just a few years, a complete archive can be saved at a cost that is 50 to 60 times lower than using traditional methods.

The Book Saver® reagent is made up of a magnesium-based neutralizing agent and a carrier that dissolves the neutralizing agent and diffuses right through the paper for maximum penetration. The result is:

- Homogeneous neutralization of the paper’s acidity.

- A uniform reduction of the alkaline reserve to prevent future acidification.

The amount of reagent to be used and the contact time between the material and reagent will depend on the condition of the material to be treated. The unit has pre-programmed cycles for treating different kinds of documents. Once the material is selected, the paper is dried to achieve a humidity percentage that optimizes the behaviour of the neutralizing agent. The books are then placed in the treatment chamber, which is closed so all the air can be extracted. The Book Saver® reagent is then released inside the chamber to impregnate the material.

After impregnation, the neutralizing agent is deposited on the cellulose fibres and the carrier is recovered. The books are then removed from the chamber and air dried, which is when the organic magnesium deposited on the fibres is transformed into carbonated magnesium. The cycle can take between four and six hours, depending on the material being treated.

A scanning electron microscope (SEM) was used to examine the cross-sectional cuttings of the sheets and show that the neutralizing agent uniformly penetrated into the interior and exterior pages. The tensile strength compared to untreated paper increased 50% on average. The fatigue strength (double fold) increased by 150% to 180%.

To find out more about the process, consult the Banik Study 

Regardless of whether the treatment is applied on site or at the facilities of CSC or one of the companies we collaborate with, the objects are identified and registered individually by book or file to ensure traceability during the entire preservation process.
The first step in mass treatment is the essential process of evaluating the material to be treated and selecting the most suitable treatment. If the object to be preserved is in a very bad state of deterioration and the essential intrinsic properties of the paper have been lost, additional stabilization processes must be applied, involving considerable additional cost. It is therefore recommended to apply a preventive preservation policy and to de-acidify collections that have not suffered major damage as a way of avoiding the need for urgent treatments in the future at a much higher cost. Unlike other treatments, when the CSC Book Saver® process is applied, deterioration is rarely observed in dyes, stamps, etc., which greatly facilitates the initial evaluation process.
CSC carries out continuous monitoring of treatment quality by means of the systematic analysis of samples at its own laboratories and at independent research institutes and control laboratories.

In cases in which it is not advisable to carry out treatment on the premises where the collection is held, the books and documents can be moved to the facilities of the CSC or one of the companies we collaborate with so the de-acidification process can be carried out. CSC carries out a rigorous screening process of its licence holders and collaborating companies, and only works with companies with a proven track record in heritage-preservation services.

The biological agents that can damage paper are essentially rodents, insects and microorganisms such as fungi and bacteria, which are able to live off the nutrients in the substances that make the cellulose materials.

The CSC Book Saver® mass de-acidification process also disinfects books, given that it involves creating a vacuum in the chamber where the books are treated so the HFC 227 carrier can be introduced. This agent itself also acts as a disinfectant because it takes action by eliminating the insects and larvae due to the lack of oxygen.

This disinfecting treatment  can be further enhanced with the CSC Book Saver® biocide treatment. The CSC Book Saver® de-acidification technology allows for the application of a set of products that inhibit microbiological growth because of the compatibility between the biocide agent and the neutralizing agent.

There are three main reasons why microorganisms thrive on cellulose material.

- Bacteria and fungi develop in conditions in which the temperature and relative humidity are high, i.e. above 22ºC and 65%, respectively.

- The accumulation of dust due to poor ventilation is also harmful, given that dust contains a great many aerobic bacteria, as well as a multitude of fungal spores.

- Besides these environmental factors, another factor strongly favours the development of fungi: the acidity of paper.

To prevent infection from fungi and bacteria, suitable preventive measures must be taken:

- The ambient humidity (relative humidity less than or equal to 50%) and storage temperature should be controlled (below 18ºC).

- Storage areas should be disinfected because, otherwise, re-infection can occur even if contaminating microorganisms are eliminated from books and documents. All new documents to be added to the collection should be checked and disinfected before storage if necessary.

- The optimum pH for the growth of cellulose-decomposing fungi is usually between 4.5 and 6, whereas the optimum pH of cellulose enzymes is usually below 6. For this reason, de-acidification of paper is essential to prevent the development of fungus and bacteria.

The determining criteria for choosing a method to eliminate fungi and bacteria are as follows:

- The efficacy of the biocide against the biological species to be eliminated.

- Possible alterations caused by the chemical products and/or the physical processes (radiation, etc.) used in the disinfection of the substrates and dyes of books and documents.

- The possible toxicity for humans and the environment of the chemical products used and the way to prevent such toxicity so these products can be applied with sufficient guarantees of safety.