Papersave

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Papersave is a process used by the Zentrum für Bucherhaltung GmbH for the mass deacidification of paper based on the Battelle system .

Acids that got into the paper during production or through environmental influences break down the cellulose , which is responsible for the mechanical strength of the paper. As a result of this acid corrosion , the paper becomes brittle and brittle. This aging is autocatalytic ; i.e., it accelerates itself.

application

Mass deacidification system

The process consists of three steps.

  • First, the documents are gently pre-dried. The natural water content of the paper is temporarily reduced from approx. 5–7% to a residual water content below 1%.
  • This is followed by the actual deacidification treatment , in which the books are soaked in an alkaline , non-aqueous treatment solution. For this purpose, the treatment chamber with the books contained therein is completely flooded by the treatment solution.
  • After the treatment solution has been pumped out, the books are dried in the last treatment step.

A treatment in the mass deacidification system lasts 2 to 3 days. This is followed by a reconditioning phase , during which the material absorbs its natural moisture content from the air. This process is generally complete in 3–4 weeks. Due to reactions of the deacidifying agent with the reabsorbed water, the materials evaporate from ethanol during this time .

Results

Deacidification completely neutralizes the acids present in the paper . The pH value measured on the treated paper is raised to the alkaline range between 7 and 9. After the acids have been neutralized, 0.5–2% excess magnesium carbonate remains in the paper, which represents the so-called alkaline reserve. This protects the paper from acids that arise later or that are introduced by environmental influences. After this treatment, the paper can be used again without restrictions and is protected against further acid damage for a long time.

Tests with artificial aging have shown that the life of deacidified papers is extended by a factor of 4 to 5.

See also

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