freeze-drying documents, books, maps, blueprints and paper

Vacuum freeze-drying is our speciality.

Our dynamic vacuum freeze-drying technique guarantees the best drying quality for all types of moist or wet paper, leather, parchment, artworks and cultural objects as well as other sensitive materials.

Obtaining optimal results.

The best results are attained if the objects aren’t further damaged during the recovery phase. This can unfortunately happen when precious time is wasted, when the wrong recovery technique is chosen or when suboptimal decisions are made on the overall procedure. An object’s condition prior to being damaged is also a significant factor.

After drying.

Water can cause extreme damage to objects that even the gentlest drying methods can’t reverse. The problems include discolouration and staining due to water-soluble dyes as well as what are known as “haloes”. Only after drying an object is it possible to see the full extent of the damage – because deformation, sticking, mould growth or peeling are difficult to see when an object is still damp. For this reason, decisions on further remediation measures are made after the object has dried. 

Materials we dry.

docusave has successfully dried the following materials: paper documents of all kind, records, business records (either loose or in ring binders), records contained in pockets and display books, library holdings, historical cultural objects such as books from various eras with a wide range of bindings (leather, wooden covers, art prints), parchment, deeds with seals, architecture blueprints, photographs, photo albums, stamps, sheet music, digital media such as CDs, Blu-ray, DVDs, X-rays, film, drawings, watercolour paintings, engravings, paintings in stretchers.

Facts and figures.

  • Time needed to dry damp documents that have been frozen: 2 to 7 days, depending on how damp the object is, the kind of material involved and the extent of the contamination
  • Time needed to dry wet documents that have been frozen: 5 to 21 days, depending on how wet the object is, the kind of material involved, the extent of contamination and whether additional measures are necessary
  • Maximum surface area of an object: 120 x 80 cm, 160 x 135 cm or 95 x 160 cm
  • Volume: docusave equipment can dry 300 to 400 kg of books at the same time
  • Experience: in the past 20 years, docusave has dried more than 1080 tons of material
  • On-site and external storage: up to 100 tons of material can be frozen directly at our premises; other, external cold storage facilities are available on request

We work with three material categories.

Category 1 – art and cultural objects
Historically valuable and high-quality objects made of leather, paper or parchment as well as objects that are sensitive due to their material or condition. Working with these objects demands extreme care. 

Category 2 – documents with a legal obligation to preserve > 10 years
Paper documents of all kind, including loose or bound business records and documents with and without folders (archival boxes, ring binders, folders, registers, envelopes and more).

Category 3 – documents with a legal obligation to preserve ≤ 10 years

Other critical factors.

Other critical factors in the drying process include how wet or damp the object is, the degree of contamination and the object’s size as well as confidentiality requirements.