Restoring antique books – with an industrial vacuum cleaner

Customer:	ZfB Leipzig
Extracted material:	Mould spores
Industry:	Other
Vacuum cleaner:	DS 1220 dust class H

The Zentrum für Bucherhaltung (ZFB - Centre for Book Preservation) in Leipzig specializes in repairing valuable antique books. These books are often stricken by mould, which finds an ideal breeding ground on the paper and the glues used. The ZFB correct this damage by disinfecting infected areas or treating them using gamma rays. Then the employees remove the residue using a thorough, careful dry cleaning process. Customers of the ZFB include libraries and archives alongside bibliophiles in their own homes.

Problem

The goal of the ZFB is to offer a higher standard in mould removal and book preservation, while ensuring excellent occupational protection. Because of this, the mouldy residues collected during cleaning needed to be reliably extracted.

Solution

Personnel use erasers, brushes or a Ruwac vacuum cleaner with a dust class H filter (HEPA filer) to mechanically remove the moulds and spores. The filter keeps out mould spores with a diameter of just 2 to 5 µm, with a maximum transmittance of only 0.005%. This means that only a maximum of five of every 10,000 particles extracted will re-enter the ambient air. 9,995 particles will be caught in the filter.

Each work station at the book restoring company is equipped with a vacuum system, and employees wear face masks while they work. The Ruwac vacuum they use to clean the books is fitted with a fine suction brush, which conserves the paper and binding but efficiently picks up dust and mould and traps it in the filter.

The extremely fine filters used on the extraction systems and vacuum cleaners and the high retention rates of the filter are essential in mould removal, because moulds and mould spores (apart from two rare species) are not a direct health hazard; however, they are potential allergens. This means that anyone coming into contact with the mould could develop an allergy, which could have unpleasant consequences as this type of microbe is found almost everywhere.