Collagen Fibril Orientation and Tear Strength across Ovine Skins

Abstract

Variability of physical properties across hides and skins requires careful consideration when manufacturing goods from leather. Therefore, an understanding of the extent of this variation and its nanostructural basis is useful. Tear strength tests were performed on ovine leather from a grid of 81 positions on skins. Synchrotron small-angle X-ray scattering measurements were made from three positions on the skin, from 26 skins. The X-ray structural measurements are compared with tear strengths of the samples. It is found that the thickness normalized tear strength does not vary greatly between different positions on the skin, in contrast to bovine hides. There is more variation between different skins than within the same skin. The collagen fibril orientation and orientation index, which has previously been shown to be correlated with tear strength, do not vary significantly between the different sampling positions in ovine skins. The collagen fibril orientation varies through the thickness of the skin in a consistent way. The consistency of collagen orientation in ovine leather between different positions on the skin is in marked contrast to bovine hides and informs the use of ovine leather for manufacturing applications.

Collagen Fibrils in Skin Orient in the Direction of Applied Uniaxial Load in Proportion to Stress while Exhibiting Differential Strains around Hair Follicles

“…It is noted that studies have been performed using small-angle x-ray scattering (SAXS) to relate collagen orientation to tear strength, but, not to changes in orientation while loading of skin [25,26]. As a result, the mechanical contribution of collagen fibrils in skin while it is undergoing loading has been mostly studied using computational and analytical models [27,28,29,30].…”

Processing of collagen based biomaterials and the resulting materials properties

“…The fibre orientation in skin is in homogenous regarding the area, the cross-sections and between skins of different animals of the same species [38–40]. The skin shows an internal tension which is observed along the Langer lines (± 10°) and which is caused by a passive pretension of the collagen fibres.…”

Influence of UV aging on some rheological properties of footwear leather

“…Moreover, the plasticity property adjusts the leather to the shape of the foot and increases a mechanical comfort [26]. Today in order to determine collagen structures, the wide spectrum of techniques as: small angle X-ray scattering [27][28][29][30], differential scanning calorimetry [31], scanning electron microscopic analysis [32] are used. These abovementioned techniques could give the indicators of leather quality from the molecular level point of view.…”