Olariu, Gheorghina (szerk.): Sesiunea Internaţională de Restaurare - Conservare (Satu Mare, 1997)
Investigaţii, conservare
Parchment behaviour during reversible treatments of spontan and controlled exposure to high relative humidity Summary By exposing to high relative humidity (RH) of air, parchment increases constantly and uniformly its wieght and surface because of hydration. The spontan exposure (without intermediate phases) to 95% RH is characterized by more abrupt curves of increasing than in the case of phases increasing of the RH. The reversibilisation of the process by spontan drying in the air leads to a gradually lowering of the weight accompanied by a violent fall of the surface curve. Controlled drying by keeping and passing the parchment proof in 3 or 4 mois chambers with succesive-decreasing RH levels ensures a slow return to the initial surface of the material without any tension devices. A list of 16 moist chambers (based on vapor tension of salt solutions) having 13 RH levers between 45-100% is given. In the same time is presented an image of a simple moist chamber made with common materials (PVC vat and polyethylene bag). The authors consider that the data presented in this paper are of interest for parchment restoration as some steps of this work consist of humid or moist treatments. 67
