Crimp in Wool: Cortical Segmentation and Tensile Properties of Well-Crimped and Abnormally Crimped Fibres of Merino Wool

Chapman, Ralph E.

doi:10.1071/bi9650689

Cited by 9 publications

(2 citation statements)

References 14 publications

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“…Associated with the latter are increases in fibre weight, diameter and strength, but loss of staple and fibre crimp (Chapman and Short 1964;Chapman 1965), in contrast to the degradation and loss of strength of the fibres associated with the former.…”

Section: Discussionmentioning

confidence: 93%

Effects of Abomasal Supplements of Methionine on the Wool Follicles and Skin of Wheat-Fed Sheep

Chapman¹,

Reis²

1978

Aust. Jnl. Of Bio. Sci.

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In wheat-fed sheep, supplemented abomasally with 1·5-6·0 g methionine per day, poor formation and improper keratinization of the wool fibres were evident 4 days after the start of the methionine supplementation. This led to kinking of the fibres. Subsequently severe distortion of the fibres, accompanied by gross thickening of the outer root sheaths, occurred in the distal (upper) halves of most follicles. Within this thickened region partial degradation of the distorted fibres occurred before emergence from the skin surface, causing a marked reduction in the tensile strength of the wool.It is postulated that kinking of the fibres stimulated the accumulation of outer root sheath cells, which led to hyperactivity of the process that normally degrades the inner root sheath, so that the poorly keratinized fibres were also partly degraded.Thickening of the epidermis and cellular infiltration of the upper dermis sometimes occurred during the infusions of methionine, whereas there were negligible" effects on the sebaceous and sweat glands.Disappearance of the excess accumulation of outer root sheath cells after cessation of the methionine supplementation occurred gradually following improvement in keratinization and elimination of kinking of the fibres.

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Section: Discussionmentioning

confidence: 93%

Effects of Abomasal Supplements of Methionine on the Wool Follicles and Skin of Wheat-Fed Sheep

Chapman¹,

Reis²

1978

Aust. Jnl. Of Bio. Sci.

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“…However, as the stain used (sodium plumbite) was degradative and correlated only partially with methylene blue staining and no ultrastructural basis of the technique was provided, it is difficult to compare Thorsen's results directly with those from this study. Four other studies have reported mean percentages of orthocortical cell areas higher than 50% for wools of various mean diameters (Ahmad and Lang 1957;Snyman 1963;Chapman 1965;Bones and Sikorski 1967), without defining relationships between orthocortical cell proportions and the diameter of the individual fibres in the samples. One of these studies (Ahmad and Lang 1957) reported that an artomalous Merino wool type averaged 55% paracortical cell area.…”

Section: Discussionmentioning

confidence: 96%

Cortical Cell Types and their Distribution in Wool Fibres

Orwin¹,

Woods²,

Ranford³

1984

Aust. Jnl. Of Bio. Sci.

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A method of determining cell types in wool fibres by methylene-blue staining has been extended to allow relationships between cortical cell type and cortical diameter to be studied in wools from individual sheep. Application of the method to wools from 12 sheep from six breeds showed that orthocortical cells were the predominant cell type produced. The percentage area occupied by orthocortical cells in a fibre cross-section increased with increasing cortical diameter in either a curvilinear (log-linear) or a linear manner. Nutritional stress or season may have affected the relationship in some sheep.

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Crosslinking structure of keratin: III. Rubberlike elasticity originating from non‐uniform structures of the swollen hair and wool fibers

Arai

Hirata

1991

J of Applied Polymer Sci

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SYNOPSISHair and wool fibers treated with an 11 M LiBr solution containing N-ethylmaleimide showed typical rubberlike elasticity in a solution composed of equal volumes of 8 M LiBr and diethylene glycol monobutyl ether. Stress-strain relations of the swollen fibers were treated with a two-phase structural model: a mechanically stable phase of higher crosslinked domains and a rubbery phase with lower crosslink density. Stress-strain curves were analyzed by applying non-Gaussian chain statistics to the swollen keratin network, including microdomains, which act as reinforcing filler particles in rubber. Swollen hair showed about 2.3 times higher modulus than wool. It has been suggested that: (1) the difference in the modulus between the two keratins is attributable to the difference in the volume fraction of domains, and ( 2 ) the crosslink density of rubbery phase in hair is virtually identical to that in wool.

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Crimp in Wool: Cortical Segmentation and Tensile Properties of Well-Crimped and Abnormally Crimped Fibres of Merino Wool

Cited by 9 publications

References 14 publications

Effects of Abomasal Supplements of Methionine on the Wool Follicles and Skin of Wheat-Fed Sheep

Effects of Abomasal Supplements of Methionine on the Wool Follicles and Skin of Wheat-Fed Sheep

Cortical Cell Types and their Distribution in Wool Fibres

Crosslinking structure of keratin: III. Rubberlike elasticity originating from non‐uniform structures of the swollen hair and wool fibers

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