Changes to Collagen Structure during Leather Processing

Abstract

As hides and skins are processed to produce leather, chemical and physical changes take place that affect the strength and other physical properties of the material. The structural basis of these changes at the level of the collagen fibrils is not fully understood and forms the basis of this investigation. Synchrotron-based small-angle X-ray scattering (SAXS) is used to quantify fibril orientation and D-spacing through eight stages of processing from fresh green ovine skins to staked dry crust leather. Both the D-spacing and fibril orientation change with processing. The changes in thickness of the leather during processing affect the fibril orientation index (OI) and account for much of the OI differences between process stages. After thickness is accounted for, the main difference in OI is due to the hydration state of the material, with dry materials being less oriented than wet. Similarly significant differences in D-spacing are found at different process stages. These are due also to the moisture content, with dry samples having a smaller D-spacing. This understanding is useful for relating structural changes that occur during different stages of processing to the development of the final physical characteristics of leather.

Experiments on Moisture Squeezing from a Leather Semi-Finished Product

“…In [2] the effect of collagen fibers and moisture content on skin stiffness was investigated. [3,4] is devoted to the study of structure state under skin processing. In [5], the strain properties and characteristics of a chrome leather semifinished product made of bovine skin were experimentally investigated according to its topographic sections and the coatings of the squeezing rolls.…”

The review of versatile application of collagen

“…The tensile stiffness of leather depends upon the preferred direction of fibers in different regions of the hide . The addition of oils penetrating the leather is an essential part in the manufacture of leather and enhances the strength and feel of leather . To provide knowledge of collagen fibril and molecular integrity necessary for the development of effective low chromium tanning systems is the main objective of research in leather technology.…”

“…In several approaches, a correlation of biophysical experiments and molecular modeling has been used as a function of bovine skin treatment with different concentrations of chromium salt . X‐ray diffraction studies enable the rapid assessment of interactions between amino acid residues in the helix and interhelical interactions within the fibrils after chrome tanning …”

Nanoconjugates of methacrylic polymers: Synthesis, characterization, and immobilization to leather

“…Several years back, he reported the use of water‐dispersible graft copolymers for leather finishing. Although most of the research efforts are traditionally directed toward the improvement of bulk properties of leather, studies of surface characteristics are important for improvement in comfort parameters like water‐vapor permeability, hydrophobicity, and water‐repellent properties . Recently, we reviewed various aspects of immobilization of polymers on different surfaces .…”