Fleece Wool Research Articles

Physical Properties and Processing of Fine Merino Lamb's Wool

The effect of wool crimp, independent of fiber diameter, on loose fiber resistance to compression and the handle of fine Merino lamb's and fleece wool was reported in Part II of this series of papers. For staples in which crimp is well defined, there is a good correlation between crimp and fiber curvature. In woolen system processing, a reduction in fiber crimp/curvature results in greater sliver bulk, more even slubbing, hairier yarns, and loftier knitted fabric. A subjective and objective evaluation of knitted and woven fabrics processed from batches combining specially selected individual fleeces illustrates how fabric handle can be engineered through the principal raw wool parameters of fiber curvature and diameter.

Physical Properties and Processing of Fine Merino Lamb's Wool

The fiber properties and handle of fine Merino lamb's and fleece wool are critically reviewed in Part 1 of this series of papers. Those objective characteristics that distin guish these two classes of raw wool and appear to account for the relative softness of hand of lamb's compared with fleece wool are presented here. The best single parameter indicating softness is resistance to compression. A reduction in staple crimp frequency or mean fibre diameter or both lowers resistance to compression and increases softness. The lower mean staple crimp frequency observed in wool grown in the first four months of a lamb's life is a visual indication of tactile softness compared with that of wool grown subsequently.

Physical Properties and Processing of Fine Merino Lamb's Wool

Literature pertinent to fiber properties and handle of fine Merino lamb's and fleece wool is critically discussed. The softness of handle of fine Merino wool varies inversely with loose fiber resistance to compression. This complex raw wool parameter has geo metric and mechanical attributes. Fiber bending and torsional rigidity are important mechanical factors that depend on mean fiber diameter, cross-sectional shape, and Young's modulus. Crimp frequency, amplitude, and form are equally important geo metric factors. Those characteristics that distinguish lamb's and adult wool and appear to account for the relative softness of hand of lamb's compared with fleece wool are presented in Part II.

Changes in Wool Colour. Part III: Processing

The clean and ‘as-is’ colours of seven lots of Australian merino fleece wool and three lots of Australian merino skirtings were measured before processing and at various stages during scouring and topmaking. The incubated colours of the raw wool and the ‘as-is’ colours of rewashed top and blank-dyed top were also measured. The ‘as-is’ brightness values, averaged over all lots, for scoured wool, carded silver, gilled sliver, combed sliver, top, and blank-dyed top were 59.8, 61.2, 62.5, 63.5, 63.7 and 61.9 Y units, respectively, compared with the clean colour of raw, greasy wool (62.6 Y units). The ‘as-is’ yellowness values, averaged over all lots, for scoured wool, carded sliver, gilled sliver, combed sliver, top, and blank-dyed top were 2.0, 3.4, 3.4, 3.3, 3.3 and 4.4 (Y − Z) units, respectively, compared with the clean colour of greasy wool (2.4 (Y − Z) units). Clean-colour (Y − Z) of raw wool was similar to the colour of scoured wool, whereas top yellowness was closer to the incubated colour of raw wool (3.6 (Y − Z)). The results suggest that the wool trade should be able to use raw-wool colour measurements (clean colour and incubated colour) to assess the processing potential of wool. The estimate of within-bale variance for clean-colour (Y − Z) was higher (×2) than the single previously published estimate, which forms the basis of sampling-precision estimates for yellowness in the Australian Standard AS-3546 and IWTO-14 (E). The within-bale variance of incubated-colour (Y − Z) was much higher (×3) than the clean-colour within-bale variance estimate.

Organophosphorus residues in wool grease resulting from specified on-farm lice and flystrike control treatments.

To investigate wool organophosphorus concentrations resulting from a range of farm pesticide application methods. Random sampling of wool for pesticide residues and on-farm interviews to determine associated treatments. Tasmanian fleece wool lots were sampled at random and tested for organophosphorus residues. The grower was identified and the pesticide treatments applied to the sheep were ascertained by on-farm interview. The residue concentrations showed a large variation that was not accounted for by differences in treatments by growers. Organophosphorus concentrations were proportional to the number of treatments applied, and inversely related to the time between pesticide application and the subsequent shearing, and were significantly influenced by the method of application. After allowing for the time of application, plunge dipping resulted in pesticide residue concentrations 2 to 2.5 times greater than shower dipping, using spray races or hand jetting, and the use of these methods caused larger residues than the use of jetting races. We recommend that plunge or shower dipping should not be used more than 7 weeks after shearing, nor at higher concentration than the standard dose rate used for lice control, whereas jetting may be satisfactory for up to 7 months after shearing, provided only one application is administered.

Fleece Grading and Wool Sorting: The Historical Perspective

Fleece Grading and Wool Sorting: The Historical Perspective

Fleece Grading and Wool Sorting: The Historical Perspective

Fleece Grading and Wool Sorting: The Historical Perspective

GANHO DE PESO E PRODUÇÃO DE LÃ DE BORREGOS CORRIEDALE SUPLEMENTAROS COM CANA-DE-AÇÚCAR E FARELO DE SOJA, E PASTAGEM CULTIVADA DE AZEVÉM

Foi avaliado o ganho de peso e produção de lã de borregos da raça Corriedale distribuídos nos seguintes tratamentos: T1 - Campo nativo (Testemunha); T2 - Campo nativo e Cana-de-açúcar (integral triturada); T3 - Campo nativo e Cana-de-açúcar e farelo de soja; T4 - Campo nativo e pastagem de azevém, sob pastejo controlado (3,0 horas dia). O experimento foi conduzido de 14/07 a 23/11/88, com animais de 8,0 meses de idade média e peso médio de 26,0kg. As diferenças dos pesos médios dos grupos de borregos T3 (32,53kg) e T4 (32,33kg) em relação aos pesos dos grupos T1 (25,25kg) e T2 (29,05kg), foram significativas estatisticamente (P < 0,01). Aos 112 dias do experimento, a diferença de peso médio do grupo T2 (32,23kg), em relação ao grupo T1 (28,98kg), também foi significativa estatisticamente (P < 0,01). As diferenças da produção média de lã do grupo de borregos T4 (2,6kg) em relação às dos grupos T1 (2,2kg) e T2 (2,1 kg) e a diferença do grupo T3 (2,5kg) em relação a do grupo T2 (2,1 kg), foram significativos estatisticamente (P < 0,01). A diferença da produção média de lã do grupo T3 (2,5kg), em relação a produção do grupo T1 (2,2kg), foi significativa estatisticamente (P < 0,05). A suplementação dos borregos neste período, apenas com cana-de-açúcar, não apresentou efeito satisfatório na quantidade de lã produzida.

Wool follicle development, wool growth and body growth in lambs treated from birth with recombinantly derived bovine somatotropin

AbstractThe effect of recombinantly derived bovine somatotropin (bST) administration on wool follicle populations, wool growth and body growth was examined in young lambs. Romney × (Border Leicester × Romney) lambs were treated with bST at doses of 0·1 or 0·3 mg/kg live weight per day, or with excipient, commencing on the day of birth and continuing at weekly intervals until the last injection was given at 11 weeks of age. Concentrations of immunoreactive somatotropin in plasma were 19·2 (s.e. 2·1), 65·2 (s.e. 2·8) and 74·7 (s.e. 4·8) μgll in the control, low dose bST and high dose bST groups, respectively. Somatotropin treatment did not alter the density of primary (P) or secondary (S) follicles in the skin, or the S/P ratio, as measured by histological examination of mid-side skin biopsy samples at 14 weeks of age. Mid-side greasy and clean wool growth during weeks 2 to 14 of the study were increased (P < 0·05) in bST-treated lambs but treatment had no effect on wool growth during the immediate post-treatment period (weeks 14 to 22), or on yearling fleece weight or wool quality characteristics. Body growth was not altered by bST administration. It is concluded that bST treatment stimulates wool growth even in very young lambs but, contrary to the results of a previous study, does not alter the development of wool follicle populations.

Modelling the FFDA fibre diameter histogram of fleece wool as a mixture distribution

The histogram of wool fibre diameters obtained by processing fleece samples through the Fibre Fineness Distribution Analyser (FFDA) machine is modelled as a mixture of two normal distributions fitted on the log scale (model iv). The paper compares this model with a single normal distribution on the natural scale (model i), a single normal distribution on the log scale (model ii) and a mixture of two normal distributions on the natural scale (model iii). When fitted to 2544 fibre diameter histograms from Merino hoggets, these models gave average lack-of-fits, distributed as �225, of 549.6, 190.1, 93.5 and 39.5 for models i to iv respectively. Model iv is proposed as the basis for describing the FFDA fibre diameter histogram in sheep breeding.

Pigmented fibres in white-skirted fleece wool from Piebald Merino sheep

White-skirted fleece wool from 68 piebald Merino sheep was divided into four portions that were sampled and measured for pigmented fibres. The piebald sheep were identified by the presence of pigmented fibre spots (usually one), varying in size from 2 mm diameter to over 50% of body surface area, and their location conformed to no particular pattern. The majority of samples for each portion (72-82%) had no detected pigmented fibres. There were 14.7% of piebald sheep with a concentration of isolated pigmented fibres (PFC) of at least 1 per 10 g scoured staples (taken to be the threshold of commercial importance) for their white fleece wool. While most PFC values were below the commercial threshold, there is a risk that some pigmented areas on piebald sheep may be missed during shearing. Of the various records taken for macroscopic pigmentation on the piebald sheep, only the scores for pigmented fibres at the horn sites (HSF) were significantly correlated (r=0.37; P<0.01) with PFC. The HSF scores were significantly correlated (P<0.05) with several other types of non-fleece pigmentation.

The Effect of Settings and Speeds throughout the Worsted Card on Combing Performance

For clean fleece wools, it is at the swift of the worsted card, rather than at the forepart, that changes in carding parameters have most effect on top length and noil and subsequent combing. Reducing the swift settings, particularly that of the last worker, reduces noil and decreases top mean fibre length, whereas, for a constant finest-worker setting, increasing the number of workers improves top length and reduces noil. A swift-to-worker surface-speed ratio of between 40 and 80 results in optimial top length and noil.

Selective Scouring of Dirt from Greasy Wool

A strategy to increase dirt recovery from wool scouring liquors was tested in a series of five trials at commercial plants. By adding nonionic surfactant and alkaline builder to a cold or warm desuinting bowl (modified system) ahead of the usual hot scouring train, a large fraction of the dirt was scoured from the wool before the grease was removed. The first bowl liquors were rich in dirt and low in grease and had good dirt settling characteristics. Without the additions (control), the desuinting bowl removed large amounts of dirt only from coarser wools with relatively high water soluble and low grease contents. In a trial on merino fleece wool with low water solubles and high grease content, the scoured product from the modified system contained less residual ash and was whiter than the product from the control system.

Selective Scouring of Dirt from Greasy Wool

Laboratory experiments using samples of eleven Australian wools representing five different classes (merino fleece, lambs, merino pieces, crossbred pieces, and pieces and bellies) showed that the dirt could be selectively removed in a warm (35 °C) suint bowl containing nonionic surfactant and alkaline builder (modified suint scouring). Removal of grease was low, and in consequence the suint bowl liquor could be readily centrifuged to give good recovery of dirt as an easily disposable spadeable sludge. In a suint bowl without additives (control), the different wools displayed two distinct modes of behavior, which could be correlated with greasy wool characteristics. The fine fleece wools gave low dirt removal; the coarser wools gave much higher dirt removal and overall recovery. Only a small amount of recoverable grease was removed. This difference in the behavior of different wools may explain the varying ideas about the effectiveness of suint bowls in industry and provides an opportunity to improve the overall efficiency of the scouring operation.

Selective Scouring of Dirt from Greasy Wool Part I: A Strategy to Improve Dirt Recovery from Scour Liquor Effluent

Laboratory experiments have shown that dirt removal by a cold suint bowl from both low and high yielding Australian merino fleece wools can increase from 10-25% to 40-60% by adding certain surfactants, builders, or their mixtures. Factorial exper iments show that increasing the concentration of the additives has the most significant positive effect on dirt removal and recovery, and grease removal. Increasing the tem perature of the suint bowl from 20 to 35°C has a less significant positive effect on each of the responses. Changing from a wool with high dirt and medium grease (low yielding) to a wool with low dirt and medium grease (high yielding) results in a lower percentage of both dirt and grease removed by the modified suint bowl, but the overall removal of both is greater than when no additives are present. Factorial experiments also show that one very effective formulation comprises a mixture of nonionic sur factant and soda ash. The settling efficiency of dirt (which determines dirt recovery) is determined in both hot and cold scour bowls containing a nonionic surfactant and soda ash. The settling efficiency decreases as the grease concentration and grease to dirt ratio in the liquor increase with continuous scouring. In all cases, dirt recovery from the modified cold suint liquor is greater than from a cold bowl containing no additives. The highest recovery is between 45-50% of the dirt entering on the greasy wool, which is over twice the recovery from a suint bowl without additives. Only a small amount of recoverable grease is removed from the fiber (less than 10% of the total grease present) by the modified suint bowl; the remaining grease removed is nonrecoverable (30-60% of the total grease present).

1—OBSERVATIONS ON THE CHARACTERISTICS OF AUSTRALIAN GREASY WOOL PART VI: THE RESISTANCE TO COMPRESSION OF MERINO FLEECE WOOLS

An analysis of the resistance-to-compression characteristics of common merino fleece wools is reported. The average value obtained under these experimental conditions was 10.0 kPa. with 95% of wools lying within ± 2.7 kPa of this value. Resistance to compression is highest among fine, short wools of better style, but, although these factors are highly significant, they account for only 45% of the total variation. Individual sale lots of the same type vary by ± 2.0 kPa about the mean value.

16—OBSERVATIONS ON THE CHARACTERISTICS OF AUSTRALIAN GREASY WOOL PART V: STAPLE LENGTH IN CROSSBRED FLEECE WOOL

A study is reported of a survey of staple-length measurements in Australian crossbred fleece wool. lt is shown that staple-length variation within a sale lot for crossbred fleece wool was much higher than that in merino fleece wools of similar fibre diameter but very similar to that of merino skirtings. The average staple length of the crossbred fleece wools was 110 mm, which was longer than that of merino fleece wools and merino skirtings of similar fibre diameter.

15—OBSERVATIONS ON THE CHARACTERISTICS OF AUSTRALIAN GREASY WOOL PART IV: STAPLE LENGTH IN MERINO SKIRTING WOOLS

A study is reported of a survey of staple-length measurements in Australian merino skirting wools. It is shown that the average staple length of all merino skirting types examined was approximately 10 mm shorter than that of all the common merino fleece types measured. The other major difference in staple-length characteristics between merino fleece wools and merino skirting wools is in the within-sale-lot variance.

Effects of control of the sheep body louse (Damalinia ovis) on wool production and quality

Groups of 35 Merino wethers under natural challenge by sheep body lice, Damalinia ovis, in south-western Queensland were subjected to four different chemical lice control treatments (arsenic, diazinon, cypermethrin and deltamethrin) over a 12-month period. Shearing took place in June. Louse populations were reduced by repeated treatments with cypermethrin. Despite high temperatures and some rainfall, populations in controls peaked at the end of summer, indicating that wool length influenced population growth. Greasy and clean fleece weights of treated sheep were higher (P<0.05) than those of controls by 0.4-1.1 kg/sheep and 0.3-0.9 kg/sheep, respectively, depending on treatment. Wool base yield was 2-45.5% higher. Sheep that were repeatedly treated with cypermethrin produced more (P<0.05) sound fleece wool (3.0 vs 1.7 kg/head greasy) and less cast fleece wool (0.1 vs 0.4 kg/head greasy) than controls. The differences in wool value between treated groups and controls ranged from $A0.45 to $A3.19 per sheep. No effect on liveweight could be attributed to treatment.

Effect of Modified Rinsing Conditions on the Whiteness of Laboratory Scoured Wool

The effect of detergent distribution and the influence of various additives to the penultimate rinse bowl on the whiteness of laboratory scouted wool was investigated. With different distributions of scouring reagents (nonionic detergent plus alkali) between bowls 1 to 3 and a rinse in bowl 4, the whitest samples of both high yielding and low yielding merino fleece wools were obtained with the following bowl compositions: bowl 1, a large amount of detergent plus alkali; bowl 2, rinse; bowl 3, a small amount of detergent plus alkali; bowl 4, rinse. The lowest whiteness resulted when all the detergent was added to the first bowl. Intermediate whitenesses were obtained when a small amount of detergent plus alkali was followed by a large amount in the later bowls. In a more conventional scouring system with constant scouring conditions in bowls 1 and 2, the addition of various builders to bowl 3 increased the whiteness in the order sodium carbonate < trisodium citrate < trisodium ethylenediamine tetraacetate (EDTA-3) < trisodium nitrilotriacetate. Analyses of the level of residual contaminantes gave a statistically significant negative linear correlation between whiteness and residual iron content for both high and low yielding wool. For the low yielding wool, statistically significant correlations aiso existed between whiteness and residual solvent extractables, residual calcium, and ash content. The improved whiteness obtained using EDTA-3 compared with no additive was also observed initially in simulated continuous scouring, but the overall whiteness decreased rapidly thereafter because of the rapid build-up of contaminants in the liquor.