Paper splitting process

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The paper splitting process is a process developed in the 1960s by the restorer Günter Müller at the University of Jena , with which paper that has been damaged (e.g. by ink corrosion ) can be restored. The paper splitting method is only used in serious cases because it is complex (and therefore costly) and the original is changed.

The procedure

The sheet of paper to be restored is placed in a special bath so that it swells and pollutants are washed out of the paper. Then the front and back are each pasted with a liner paper (carrier paper) coated with gelatin adhesive, the liner papers being pressed on in a hydraulic press . As an alternative to being placed in a bath, the liner papers can be slightly dampened so that the moisture can penetrate the work of art. The swelling of the leaf allows it to be pulled apart and split in half. Now a thin, acid-free and buffered Japanese paper (core sheet) is glued in between under pressure and thus the two original paper halves are connected again. Calcium carbonate in the core sheet bonding acts as a buffer against acids that may arise in the future . In the last step, the liner papers are removed again in an immersion bath with enzymes , dissolving the gelatine adhesive.

The technological limitation of the process lies in the fact that the original sheets are not always evenly split, which is due to the large variety of countless types of paper, despite careful and exact procedures. No paper has a completely homogeneous fiber structure and an even distribution of fillers at every point across its cross-section. This internal structure is very important for the capillary structure and the gradual distribution of strength properties in the blade cross-section. This applies to both hand-made and machine-made papers in different ways. Because of these unavoidable and manufacturing- related properties, the two sides of a paper are referred to as the face and wire side . Logically, these questions also influence the technology of the paper splitting process.

History

literature

  • Robert Schumann: Notes in need . picture of science 8/2000 pp. 22–26
  • Douglas Cockerell: The book cover and the care of the book. Reprint of the 2nd German edition, Leipzig 1925, ISBN 3-88746-382-X , Edition libri rari, Th. Schäfer, Hanover 1998 (general about book restoration)

Web links

For paper splitting:

More about restoration: