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Relationshipbetween single fiber length and diameter in Australian superfineMerino wool (ASFW) and Inner Mongolia cashmere (IMC) and theirdistributions within true diameters, lengths and diameter-lengthgroups

Woolproduction is an important aspect in the country’s economy. Apartfrom ensuring adequate wool products for consumers within thecountry, it is also utilized for foreign exchange. It therefore earnsthe country foreign income. The functionality or rather objectives ofindustries differ across the industries. However, the main objectivesin most of the wool-producing industries include producing fine,strong fibers with relatively equal diameters. However, this is notthe case in that alterations in the length of fibre (L) are normallyaccompanied by variations in diameter of the fibre (D). This resultsin production of a fibre that has a variable cross-sectional areaalong its length and is considerably weaker (1). On a lighter note,the connection between the length and diameter of fiber can bebroken. This is because at certain conditions, like establishment oflysine-deficient proteins, the length and diameter tend to move incompletely opposite directions (2). Thyroxine or thyroidectomyprovision to intact sheep gives a variance in Length without anyrelated changes in diameter (3). In addition to that, changes inhormonal conditions as well as low skin temperatures lead decrease inlength with no resultant change in diameter (4, 5). As illustratedrecently, periodic wool development within the Romney sheep is inline with the variations in diameter and length which are out ofphase. The variances in length happen before variations in diameterdo (6). The physiological as well as cellular techniques controllingthe length and diameter are quite intricate. These were theconclusive remarks of the authors who also think the mechanisms arepartly independent. However, attempts to identify them has yet to bemade. The techniques utilized in regulating fiber dimensions includedimensions and packing mode of the cortical cellspost-keratinization, rates of migrating cells entering the inner rootsheath and fiber, proportions of cell production within the germinateportion of follicle bulb and the rates of new cells maintained toaccommodate bulb dimension variations (7,8,9). Probably, some of thisfeatures are related to follicle morphology, particularly shape andsize of the dermal papilla and follicle bulb. In accordance Henderson(10), there exists considerable relations between follicle dimensionsand length and diameter, follicle size: fiber size relationshipsvaried between and within sheep. This affirms that processes ratesdetermine fiber dimensions. However, measurement rates not madewithin the study.

Generally,the mean staple length of Australian wool is the same i.e. there isno considerable variance from one year to the other (11). It isroughly 90 mm per 12-month development. It also tends to vary acrossdifferent regions. Additionally, finer bloodlines have less shortstaple lengths typically 85 mm in terms of fine wool hogget ewes, and94 mm that is for medium and tough wool bloodlines. There tends to bea correlation between diameter and fiber length in a singular woolstaple (12). Shorter fibers are generally finer. However, thecorrelations seem to disappear when considering a whole sheep.Additionally, single fiber length as well as staple length differ inaccordance to the positioning of the sheep. A positive relationbetween diameter and length also tends to exist in a fleece or staple(13, 14). The fibre diameter and fibre/staple length also tend tohave a positive relation (15), and also between sheep, especially ifthe breeds of sheep differ. Considering the ratios, the ration ofgrowth of fibre length in a particular season to the average fibrediameter i.e. L/D, tends to differ broadly between sheep, fromroughly 10 to about 20. However, it is somehow constant withalterations in wool growth (16). The carding process tends to causesubstantial breakages of fibre further reducing the correlations.This is because, longer fibres are prone to breakages (17). Asconfirmed across many New Zealand wools such as merinos, a positiverelation exists in wool tops.

Variousstudies have been made to examine the measurement and fibre diameterspread implications (18, 19, 20). For instance, Crook and theco-workers assess the relation involving wool quality and fibrediameter changeability. Over the years, studies have continually beenmade to illustrate the impact of fibre diameter distribution featuresas well as variability on product quality i.e. garment and fabriccomfort and processing performance. Fibre diameter changeabilityespecially along-fibre variability, poses a considerably high impacton staple and fibre strength. Additionally, it impacts on fibrebreakage while in the processing state especially carding, since thefibres tend to break along the thinnest junctures. Fibre diametervariation also entails a small and rather considerable impact on meanquantity of fibres within the yarn cross-section, yarn evenness,neps, thickness faults and spinning performance. This has a relationto prickle (scratchiness) and fabric handle. Considering two woolmodels with similar average fibre diameter, they could be havingdiverse fibre diameter distribution features. This includes,proportions of fibres with diameters greater than certain thresholdvalues. In addition to that, averagely, around 70 percent of meanfibre length variations in a flock are accounted for through thedisparities in stable length (23, 24, 25). In line with that, around80 percent of the entire fibre length changeability is due todisparities among fibres in the staples. 10 percent of the entirevariation cab be due to variations among staples in the fleece. Theremaining 10 percent can be attributed to variations among thefleeces. In relation to the above studies, Rottenbury et al. (26)also affirmed that in a flock, the between-fleece element I lesssignificant as compared to the length variability entailed in thefleece. They also asserted that a minute ration of the variabilityentailed between different fleeces tends to be minimized by recentclassing procedures. In other words, variability between fleeces wereless significantly affected by classing procedures.

Thisresearch has elaborated the immense linear correlation involvingfibre length and single fibre diameter for unprocessed IMC and ASFW.The study effectively confirms existence of a positive connectionbetween fibre length and single fibre diameter. The diameter andlength connection tends to weaken after wool handling into a top.However, the relation still has a positive correlation. The studyalso puts emphasis on variances in length as well as diameterdistribution in true lengths, diameters as well as diameter –length groups. It is also highly efficient on yarn evenness.Assumptions from various studies outline the positive correlationbetween these two aspects in several stages. The studies have alsoillustrated the effect of fibre diameter distribution features onproduct quality including garment and fabric comfort. The resultsshow a positive relation in the above facets.