The hairiness of worsted wool and cashmere yarns and the impact of fiber curvature on hairiness

In this study, a range of carefully selected wool and cashmere yarns as well as their blends were used to examine the effects of fiber curvature and blend ratio on yarn hairiness. The results indicate that yarns spun from wool fibers with a higher curvature have lower yarn hairiness than yarns spun from similar wool of a lower curvature. For blend yarns made from wool and cashmere of similar diameter, yarn hairiness increases with the increase in the cashmere content in the yarn. This is probably due to the presence of increased proportion of the shorter cashmere fibers in the surface regions of the yarn, leading to increased yarn hairiness. A modified hairiness composition model is used to explain these results and the likely origin of leading and trailing hairs. This model highlights the importance of yarn surface composition on yarn hairiness.

Determination of cashmere and wool fibre scale frequency by analysing diameter profiles with fast fourier transform

This paper describes a potentially faster and cheaper method of determining fibre scale frequencies. The method uses the single fibre analyser (SIFAN) to  determine the along the fibre diameter profile. This information is then analysed by the Fast Fourier Transform technique using computer software. The paper shows the close association between the mean scale frequencies determined by this method and the traditional approach using SEM.

Cashmere and wool cortical cells

This paper proposes that instead of the expensive and difficult task of examining the morphology of fibre cuticle scales that an alternative approach of examining the internal morphology of cortical cells may be faster and cheaper. Preliminary data were presented and further work is required.

FTIR and thermal analysis of cashmere and other animal fibres

In this paper, sereval varieties of animal fibres including cashmere and Australian fine Merino wool have been analysed by Fourier transform infrared microscope and differential scanning calorimeter. The results showed that both Chinese and Australian cashmere fibres started absorbing heat at a relatively higher temperature but were thermally degraded quicker than other animal fibres tested. However, the mass changes (within the temperature range of 200oC to 350oC) and associated onset temperatures varied among fibre varieties. From the attenuated total reflectance spectra, the Chinese cashmere was clearly different from Australian cashmere and wool in a peak near 1040 cm-1 wavelength for S-O stretching of cysteic acid residues. The Chinese cashmere presented a stronger absorption at 1019 cm-1 wavelength, while Australian cashmere and wool peaked at 1079 cm-1 wavelength and had a weaker absorption. Combined with thermal analysis, the normalised R-SO3 - content of cysteic acid residues to the amide II peak of the protein backbone may have potential use in identifying Australian fine Merino wool from Chinese cashmere.

An update on the Australian cashmere industry

This paper gives an up-to-date overview on the Australian cashmere industry.  It covers the development history of Australian cashmere industry, the characteristics of Australian cashmere fibres, cashmere processing and research and development in Australia.

A study on dehairing Australian greasy cashmere

Cashmere is a luxury fiber with high international demand. Australian cashmere fleece is shorn rather than hand combed, and the shorn fleece contains a large quantity of coarse guard hair. Normally raw cashmere fleece is scoured first, followed by dehairing to eliminate the coarse guard hair. But scouring the unwanted guard hair consumes a large quantity of water, and increases the cost of cashmere processing in Australia. Ideally, the guard hair should be removed first and then the fine cashmere fibers are scoured for further processing. This paper reports trial results on dehairing greasy rather than scoured Australian cashmere fleece, with the aim of reducing scouring cost and water consumption. The quality of cashmere fibers after the conventional dehairing process and the new greasy dehairing process has been assessed. The results indicate that fiber quality from the greasy dehairing process is better than that from conventional scouring then dehairing process.

Dehairing Australian alpaca fibres with a cashmere dehairing machine

Many classes of alpaca fibres contain a certain amount of coarse fibres, which are strong and stiff, and cause discomfort to the end users of the alpaca fibre products. It is therefore desirable to separate the coarse fibres from the fine alpaca fibres. This paper reports trial results on alpaca dehairing using a cashmere dehairing machine. The diameters of alpaca fleece, dehaired alpaca fibres and removed alpaca fibres were analysed, and the fibre lengths before and after dehairing have been compared. The results indicate that it is feasible to dehair alpaca fibres using a cashmere dehairing facility. The dehaired alpaca fibres are cleaner, bulkier and softer, with around 1.5 μm reduction in average fibre diameter, but the dehairing process shortens the dehaired fibre length considerably. The dehairing effectiveness of coarse fibre removal using the cashmere dehairing technology has also been discussed in this paper.

Current knowledge of the environmental influences on Australian cashmere production and quality

Goat fibre production is affected to a similar extent by genetic and environmental influences. Environmental influences include bio-geophysical factors (photoperiod, climate-herbage system and soil-plant trace nutrient composition), country of origin, nutrition factors (live weight, growth patterns) and management factors (farm, herd age and sex structure). Nutrition and management influences discussed include rate of stocking, energy nutrition, live weight change, parturition and management during shearing. The nutritional variation within and among years is the most important climatic factor influencing cashmere production, fibre diameter and fibre curvature (crimp). With productive cashmere goats, large responses to energy supplementation have been measured with optimum nutritional management. The effects and importance of management and hygiene during fibre harvesting (shearing) in producing quality fibre are emphasised.

Critical evaluation of cashmere nutrition experiments and suggestions for the design and conduct of successful experiments

Cashmere fibre production is an order of magnitude less than fibre production of Merino sheep or Angora goats and is more difficult to measure. Based on a comparison between cashmere experiments reporting responses to nutrition and those reporting no response, 13 design and management characteristics were identified that are related to the ability of experiments to discriminate among treatments. Methods must be adopted to reduce the variance in cashmere production within treatments, by using sufficient. animals per treatment, having enough replication to provide plenty of degrees of freedom to reduce error terms in analysis, and using pre-experimental cashmere production attributes as co-variants in analysis. It is preferable to use more productive and older goats, and goats that are used to handling, and to the conditions and feed to be used. Nutrition treatments need to produce different live weight growth curves and an appropriate control is needed such as live weight maintenance. As the raw cashmere fleece is composed primarily of hair and other contaminants, careful attention is required to measure, sample and test cashmere. Cashmere growth experiments should start by midsummer and last for at least four and preferably six months. These requirements make it more difficult for many university students to plan, undertake and complete long-term cashmere nutrition experiments without considerable management support.

Identification of cashmere and superfine merino wool with wavelet texture analysis

This paper presents the use of the wavelet transform to extract fibre surface texture features for classifying cashmere and superfine merino wool fibres. To extract features from brightness variations caused by the cuticular scale height, shape and interval provides an effective way for characterising different animal fibres and subsequently classifying them. This may enable the development of a completely automated and objective system for animal fibre
identification.

Lipid composition of cashmere goat fibres

This study examined the differences in the chemical composition, particularly fatty acids, of the lipid extracted from the fibre of bucks, does and castrated goats. The study provides a more detailed understanding of the chemical composition of buck fibre lipid and how it varies throughout the year, and also details the effect of body region and nutrition on the production and chemical composition of lipid from buck fibre. Lipid was extracted with either petroleum ether (non-polar) or chloroform/methanol azeotrope (polar) and analysed by gas chromatography and gas chromatography-mass spectrometry. The more polar solvent system extracted larger amounts of lipid and more of each individual fatty acid. The following buck specific ethyl branched fatty acids were identified: 2-ethylhexanoic, 4-ethylhexanoic, 2-ethyloctanoic, 4-ethyloctanoic, 6-ethyloctanoic, 2-ethyldecanoic, 4-ethyldecanoic, 2-ethyldodecanoic, 6-ethyldodecanoic, 4-ethyldodecanoic, 2-ethyltetradecanoic, 6-ethyltetradecanoic, 4-ethyltetradecanoic, 2-ethylhexadecanoic and 4-ethyloctadecanoic acids. Of these buck specific fatty acids only 4-ethylhexanoic (T), 4-ethyloctanoic, 4-ethyldecanoic, 4-ethyldodecanoic, 6-ethyldodecanoic (T), 4-ethyltetradecanoic, 2-ethylhexadecanoic (T) and 4-ethylhexadecanoic acids have been previously identified or tentatively identified (T) in buck fibre extracts. This shows that the chemical composition of buck fibre lipid is more complex than previously reported, and that it may be more difficult than previously thought to artificially duplicate the odour of the buck. Buck fibre samples had lower average concentrations of 2-methylpropanoic, 2-methylbutanoic, iso-pentadecanoic, anteiso-pentadecanoic, iso-hexadecanoic, anteiso-heptadecanoic, iso-octadecanoic and anteiso-nonadecanoic acids as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The reduced concentrations of these fatty acids in buck fibre extracts were likely to be due to the synthesis of ethyl branched derivatives of iso and anteiso fatty acids. Buck fibre samples had higher concentrations of benzoic acid as compared with fibre samples from does, spayed does, or wethers that were castrated at one month of age. The significance of these results is that non buck specific fatty acids may also make a contribution to the odour of bucks. When fibre samples were collected at various times throughout the year, it was found that the bucks had increased amounts of lipid and ethyl branched fatty acids in fibre samples shorn from March to September, as compared with fibre samples shorn in November and January. The increase in the amount of lipid and ethyl branched fatty acids corresponded with both the rutting period of the buck and the period when the buck odour was increased. This suggests that ethyl branched fatty acids could be pheromones. The variation in lipid content and fatty acid composition was also examined between fibre samples collected from different body regions of the buck during April, as alterations in sebaceous gland activity around the neck during rutting have been reported. It was found that the average amount of lipid in the neck region of the bucks was not statistically higher than the average amounts in the midside and hind regions. However, the ethyl branched fatty acid concentrations were statistically higher in the fibre from around the neck as compared with the fibre from the other body regions, which is consistent with the odour of the buck being most pronounced around the head and neck region. The lipid content and composition of fibre samples from bucks fed high and low quality diets (lucerne and pangola grass, respectively) was examined to determine the effect of nutrition on buck specific components. The high quality diet increased the amount of lipid and ethyl branched fatty acids in fibre samples collected in April from the neck, midside and hind regions, as compared with fibre samples from the corresponding body regions from bucks fed the low quality diet. Thus it may be possible for the pheromone levels of bucks to be increased by simply providing them with good nutrition. The lipid content and ethyl branched fatty acid concentrations of fibre samples increased earlier in the year for the lucerne fed bucks as compared with the pangola grass fed bucks. The lucerne fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during December to June (6 months) whereas the pangola grass fed bucks had increased concentrations of ethyl branched fatty acids in fibre samples shorn during April to August (4 months). These observations show that good nutrition can result in both the earlier production of ethyl branched fatty acids and an extended period when ethyl branched fatty acids are produced. This suggests that nutrition can be used to manipulate pheromone levels in the buck. The period when the ethyl branched fatty acids were increased corresponded with the period when the plasma luteinizing hormone (LH) and testosterone concentrations, odour and sebaceous gland volume of the bucks were increased, which supports the assumption that ethyl branched fatty acids are involved in odour production and act as pheromones.