Oral · Pages 194–203
Abstract
Research summary supplied by the authors
The shrinkage of leather under the infl uence of alternate climate conditions, especially under the infl uence of dry heat, re- stricts the usability of leather e.g. in the automotive sector. Leather shrinkage results in either a loss of dimension or, if the leather is tightly fi tted, isometric strength development. In the present study, some key factors affecting the leather shrinkage of chrome-free leathers were investigated. It was found, that reversible dimensional changes occur due to adsorption and desorption of moisture under changing envi- ronmental conditions. Irreversible shrinkage of leather, however, is caused by changes at the molecular level of the collagen triple helix. Under dry heat conditions, a partial denaturation of the collagen triple helix can be observed, but without leading to the complete coiling known from hydrothermal denaturation. The higher the degree of crosslinking of the pretanning, the higher the leather shrinkage. The retanning agents have the greatest infl uence on leather shrinkage. The infl uence on shrinkage correlates with the infl uence on molecular stability to dry heat and changing moisture content. In the study, the relationship with the chemical structure of the retanning agents will be discussed in more detail. Fatliquors have only a minor infl uence on leather shrinkage. With the knowledge gained, leathers were produced that showed excellent results in terms of shrinkage force.