We have compared the mechanical properties of wool fibers from three different breeds of sheep, Lincoln, Chokla, and Merino. The tensile moduli are highest for Lincoln, followed by Chokla and Merino fibers, but there is a reverse trend in the torsional modulus. The differences in mechanical properties are explained in terms of differences in the histological structure of the cortex, i. e., the content and arrangement of ortho and para cells, and they are correlated to crystallinity, molecular orientation, glass transition temperature, and matrix rigidity.
Get full access to this article
View all access options for this article.
References
1.
Andrew, M.W. , Feughelman, M., and Mitchell, T.W., Torsional Rigidity of the Ortho- and Paracortex of Wool, Textile Res. J.32, 421-422 (1962).
2.
Balkey, P.R. , Earland, C., and Jalihal, M.R., Studies on Magra (Indian) Wool, Part I: The Physical and Chemical Properties, Textile Res. J.37, 688-696 (1967).
3.
Bhogale, G.D. , and Whiteley, K.J., SomeRheological Properties of Indian Carpet Wools , Textile Res. J.33, 161-162 (1963).
4.
Burley, R.W. , and Speakman, J.B., Plasticity of Wool, II: Variation with Type of Follicle, Textile Res. J.23, 702-710 (1953).
5.
Carter, H.B. , Onions, W.J., and Pitts, M.O., The Influence of Origin on Stress Strain Relations of Wool Fibres, J. Textile Inst.60, 421-429 (1969).
6.
Chaudhuri, S.K., CanaryYellowing of Indian Wool, Doctoral thesis, UMIST, Manchester , 1975.
7.
Collins, J.D. , and Chaikin, M., The Stress-Strain Behavior of Dimensionally and Structurally Non-Uniform Wool Fibers, Textile Res. J. 35, 777-787 (1965), 39, 121 ( 1969).
8.
CRC Hand Book of Chemistry and Physics, 49th ed., E-37, R. C. Weast, Ed., The Chemical Rubber Co., Ohio, 1969.
9.
Crewther, W.G. , The Effect of Disaggregating Agents on the Stress-Strain Relationship of Wool Fibers, Textile Res. J.42, 77-85 (1972).
10.
Curiskis, J.I. , and de Jong, S., Relevance of the Tensile-to-Torsional Moduli Ratio E/G as a Measure of the Mechanical Anisotropy of Wool, Textile Res. J.55, 509-510 (1985).
11.
de Jong, S. , and Curiskis, J.I., Anisotropy of Wool, Textile Res. J.54, 718-725 (1985).
12.
Denby, E.F. , Young's Modulus of Keratin in Compression , Textile Res. J.31, 69-70 (1961).
13.
Dobb, M.G., Electron Diffraction Studies of Cortical Cells, J. Textile Inst.61, T232-234 (1970).
14.
Feughelman, M., The Relationship Between the Structure and the Mechanical Properties Keratin Fibres, Appl Polym. Sym.18, 757-774 (1971).
15.
Feughelman, M., Keratin, in "Encyclopedia of Polymer Science and Engineering," vol. 8, Wiley, NY, 1987, pp. 566-601.
16.
Feughelman, M., and Haly, A.R., The Mechanical Properties of Ortho and Para like Components of Lincoln Wool Fibers, Textile Res. J.30, 897-900 (1960).
17.
Kulkarni, V.G. , Robson, R.M., and Robson, A., Studies on Ortho Cortex and Para Cortex of Merino Wool, Appl. Polym. Sym.18, 127-146 (1971).
18.
Le Roux, P.L. , and Speakman, J.B., Plasticity of Wool: Part VI: The Physical And Chemical Causes of Variation, Textile Res. J.27, 1-7 (1957).
19.
Lundgren, P. , and Ward, W.H., in "'Ultrastructure of Protein Fibers," R. Borasky, Ed., Academic Press , NY, 1963, p. 64.
20.
Meredith, R. , The Torsional Rigidity of Textile Fibres, J. Textile Inst.45, T489-503 (1954 ).
21.
Morton, W.E. , and Hearle, J.W.S., "Physical Properties of Textile Fibers ," The Textile Institute, Butterworths , London , 1962.
22.
O'Connel, R.A. , and Lundgren, H.P., Comparison of Wools Between and Within Several Breeds of Sheep, Textile Res. J.24, 677-685 (1954).
23.
Postle, R., Carnaby, G.A., and de Jong, S., "The Mechanics of Wool Structures", Ellis-Horwood Ltd., Australia, 1988, p. 27.
24.
Rama Rao, D. , Influence of Moisture Sorption on Mechanical Properties of Indian Wools, Ind. J. Textile Res.10, 80-83 (1985).
25.
RamaRao, D., Property-Structure Correlations in Some Wool Fibres, Doctoral thesis , Indian Institute of Technology, Delhi, 1989.
26.
RamaRao, D., and Gupta, V. B., Birefringence in Wool Fibers, Textile Res. J.61, 000-000 (1991).
27.
Ryder, M.L., and Stephenson, S.K. , "Wool Growth," Academic Press, London-New York, 1968.
28.
Speakman, J.B. , The Rigidity of Wool and Its Changes with Adsorption of Water Vapour, J. Textile Inst.25, 92 (1928).
