Patent DE-102008032639-A1 (DE)
Title: Modification of paper documents, books, archival documents and other documentary material by influence of modifying substance in the form of aqueous solution, comprises subjecting documents in closed chamber of sub-deformation impregnation
Inventor: JABLONSKY MICHAL
IPC: D21H25/18
Filed: 2008-07-11
Abstract: The method for the modification of paper documents, books, archival documents and other documentary material by the influence of modifying substance in the form of an aqueous solution, powder or water, comprises subjecting the documents in a closed chamber of a sub-deformation impregnation by a repeated cycle of the influence of natural and over-saturated solution of a water-soluble modifying substance to achieve a humidity of 30%, pressing for 24 hours and then drying up to reaching a maximum humidity of 7%. The deformation variation of the dried document by its planarity is highly 0.5 mm. The method for the modification of paper documents, books, archival documents and other documentary material by the influence of modifying substance in the form of an aqueous solution, powder or water, comprises subjecting the documents in a closed chamber of a sub-deformation impregnation by a repeated cycle of the influence of natural and over-saturated solution of a water-soluble modifying substance to achieve a humidity of 30%, pressing for 24 hours and then drying up to reaching a maximum humidity of 7%. The deformation variation of the dried document by its planarity is highly 0.5 mm and the cycle is repeated again up to reaching the required retention of modifying substances which corresponds to the integral total applied amount of 0.5-6 kg after finishing the cyclic application of per kilo of the absolutely dried document or up to reaching the pH-value of 7-8.5 or an alkalinity of 0.5-2.5% of calcium carbonate-equivalent. The closed chamber is an impregnation chamber, a reactor or an alkaline mist chamber for deacidification. The natural and over-saturated solution of the water-soluble modifying substance is used in the form of aerosol with droplet sizes of 60 micrometer. Before and/or after the repeated cycle of the influence of natural and over-saturated solution of the water-soluble modifying substance, the modifying substance in powder and/or water form is separately applied on the document surface in the closed chamber by subsequently pressing and drying in the closed chamber under the development of the aqueous solution of the modifying substance directly on the surface or in situ in the structure of the paper or in the material of the actual document. The aerosol of the natural and over-saturated solution of the water-soluble modifying substance is applied with air stream through separate sheets on the surface of the document sheets in the closed chamber, which is provided with nozzles. The documents and/or nozzles implement a straight line backward movement or a mutual straight line backward movement, or a rotational movement or a mutual rotational movement and the air or the aerosol flows between the individual sheets of the documents. The aerosol of the solution of water-soluble modifying substance is applied on the sheet surface of the documents using mechanical or pneumatic device. After applying the solution of the water-soluble modifying substance or water, the drying of the document is carried out with a drying agent or with particles of hygroscopic or modifying substances reacting with water. The repeated application of the solution of the water-soluble modifying substances and the subsequent drying of the treated document are automatically controlled. The deformation is controlled by maximum humidity of the documents after the application.