Servizi

Books and paper documents cleaning and recovery

Thanks to our book cleaning service, at per we can recover paper goods and documents that have been contaminated or damaged by soot and smoke or by humidity after a direct soaking or after being stored in premises with a higher relative humidity than the hygroscopic balance point of the good. Paper goods that don’t present irreversible damage can be treated to regain their correct chemical cleaning, partially or totally recovering their original aspect. We guarantee the readability of all the documents whose damage has been evaluated as reversible.

Humidity and soaking damage

Paper is a fiber material with a good water absorption capacity (hygroscopicity). When kept in humid places, it can easily undergo a degradation process, since it collects water particles from the air and takes them in like a sponge. The first consequence of this is an increase in volume and the corrugated and wrinkled aspect of paper. When it is subject to different weather condition than those of its hygroscopic balance point, paper loses compactness and lacerates, ink blurs and pages sticks together like “glue”. For this reason, after a damage it is important to guard the documents in dry and ventilated places to avoid moisture absorption and the consequent paper deformation. Moreover, keeping paper in highly humid places may lead to spore formation, mold proliferation and to the irreversible degeneration of both paper tissue and ink. per choses different technologies and procedures according to treated object, damage and related extent, and time elapsed. All of per‘s procedures are certified by the Department of Organic Chemistry of Pavia University as suitable methodology to the effective recovery of paper objects.

Smoke or sooty gases damage

Fire releases a great amount of gases containing sooty dusts and particles that are hazardous for human health, like PAH and dioxin. The microscopic fiber tissue of paper absorbs these particles, making it a high-potential contaminant if not professionally removed. Goods contaminated by gases are isolated and managed carefully: sooty particles are removed through compressed air suction and blowing. The process ends with the sponge application of diluted alkaline products. For book sides and to delete smoke stains from the pages, we use specific chemical erasers and sponges.

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Drying treatment

This procedure provides a perfect chemical drying to give paper its pre damage hygroscopic balance back. Drying reconditioning is used for paper goods whose readability must be preserved. After this procedure the paper will show the corrugated surface that characterizes flooding, but it will partially recover its original aspect. We first evaluate what can and cannot be recovered. Afterwards, the objects to be treated are separated so that their weight does not damage the documents. Drying is obtained by blowing dry air in polyethylene shells placed around the paper objects to insulate them completely. Depending on the amount of goods to be treated, this reconditioning can be carried out even on-site, to speed the intervention times. For this reason, after a damage it is important to guard the documents in dry and ventilated places to avoid moisture absorption and the consequent paper deformation. Moreover, keeping paper in highly humid places may lead to spore formation, mold proliferation and to the irreversible degeneration of both paper tissue and ink. per choses different technologies and procedures according to treated object, damage and related extent, and time elapsed. All of per‘s procedures are certified by the Department of Organic Chemistry of Pavia University as suitable methodology to the effective recovery of paper objects.

Freeze-drying treatment

Freeze-drying is a physical process that removes water from an object after freezing and evaporating it in a vacuum environment. After vacuum-freezing all the documents, they are transferred inside specific machinery that can reach high temperatures. Water particles abandon paper fibers and turn into steam without passing to the liquid state, and are absorbed by the in-built ventilation devices of the machinery. Sublimation avoids further damages to the documents by saving the structure of paper and other materials (leather ligatures, parchment, wood etc), and prevents mold proliferation.

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