Artificially modified collagen fibril orientation affects leather tear strength

• Published in: Journal of the science of food and agriculture 2018-07, Vol.98 (9), p.3524-3531
• Main Authors: Kelly, Susyn J, Wells, Hannah C, Sizeland, Katie H, Kirby, Nigel, Edmonds, Richard L, Ryan, Tim, Hawley, Adrian, Mudie, Stephen, Haverkamp, Richard G
• Format: Article
• Language: English
• Subjects: Collagen; fibril; Fibrils; Leather; Organic chemistry; Orientation; Pickling; Skin; small‐angle X‐ray scattering; strength; Synthetic products; Tanning; Tear strength; Tearing
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.8863

BACKGROUND Ovine leather has around half the tear strength of bovine leather and is therefore not suitable for high‐value applications such as shoes. Tear strength has been correlated with the natural collagen fibril alignment (orientation index, OI). It is hypothesized that it could be possible to artificially increase the OI of the collagen fibrils and that an artificial increase in OI could increase tear strength. RESULTS Ovine skins, after pickling and bating, were strained biaxially during chrome tanning. The strain ranged from 2 to 15% of the initial sample length, either uniformly in both directions by 10% or with 3% in one direction and 15% in the other. Once tanned, the leather tear strengths were measured and the collagen fibril orientation was measured using synchrotron‐based small‐angle X‐ray scattering. CONCLUSION The OI increased as a result of strain during tanning from 0.48 to 0.79 (P = 0.001) measured edge‐on and the thickness‐normalized tear strength increased from 27 to 43 N mm−1 (P