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Triboelectrification has been a well-known phenomenon for a long time. Although there are numerous debates regarding the actual mechanism involved in this, there are few interesting works uncovering its unique signatures. In this work, triboelectrification of needle punched nonwoven structures has been explored from a few important perspectives. The effect of linear density of constituent fibre on the triboelectric charge generation ability of needle punched nonwoven structures has been investigated. Further, the influence of antistatic agent on the triboelectric charge generation has been enlightened. An attempt has also been made to correlate the structural parameters of nonwoven with its triboelectrification performance. This research work not only reveals the triboelectrification phenomenon of this fibrous structure but also it is a food for novel thoughts on triboelectric charge generation process. [Display omitted] • Effect of fibre fineness on triboelectrification of needle punched nonwovens is studied. • Influence of scouring treatment on triboelectrification of needle punched nonwovens is investigated in a systematic manner. • Applications associated with triboelectrification of needle punched nonwoven are demonstrated. [ABSTRACT FROM AUTHOR]

Cotton fibre maturity is the measure of cotton’s secondary cell wall thickness. Both immature and over-mature fibres are undesirable in textile industry due to the various problems caused during different manufacturing processes. The determination of cotton fibre maturity is of vital importance and various methods and techniques have been devised to measure or calculate it. Artificial neural networks have the power to model the complex relationships between the input and output variables. Therefore, a model was developed for the prediction of cotton fibre maturity using the fibre characteristics. The results of predictive modelling showed that mean absolute error of 0.0491 was observed between the actual and predicted values, which show a high degree of accuracy for neural network modelling. Moreover, the importance of input variables was also defined.

The combining ability effects were evaluated through line x tester analysis for the identification of best general combiners and specific combiners for fibre quality traits in 30 novel hybrids. The results revealed the presence of considerable genetic variation with respect to various fibre quality traits and significant differences for all the traits except elongation percentage and fibre fineness in both first and ratoon crops and indicated that the sca variances were higher than the gca variances for all the studied traits. The ratio of σ2 gca/σ2 sca was less than one for all the traits indicating the preponderance of dominant gene action, which plays an important role in the exploitation of heterosis through hybrid breeding. Parents AFRICAN I-2 and SVPR 4, KC 3 and SURABHI were found to be good combiners for fibre length and elongation percentage. The parent SUVIN was good combiner for fibre fineness. The sca effects revealed the best specific combinations viz., (i) the hybrids KC 3 x TCB 209, SVPR 4 x CCB 36 and SVPR 4 x TCB 209 for fibre length; (ii) AFRICAN I- 2 x DB 3 for uniformity ratio; (iii) COD 5-1-2 x DB 3, KC 3 x DB 3 and SURABHI x TCB 26 for fibre fineness. [ABSTRACT FROM AUTHOR]

Fabrics made from cotton, cashmere, flax, hemp, ramie, jute, and wool fibres, have been used to investigate and analyze the prickle comfort properties of fabrics worn as garments. Physical properties include single-fibre critical load, compression and bending modules, which greatly affect the fabric physiological comfort. The fibres are tested using a 'fibre axial compression-bending analyzer'. The behavior mechanisms of single-needle fibre are also analyzed, evaluated, and explained using fibres critical load, fineness, and protruding length. Physical and neuro-physiological basis for prickle sensation force from single-needle fibre depends on its bending modulus and axial compressive behavior. This experimental work shows that the bending modulus of ramie, jute, and wool fibre is significantly high as compared to other fibres. Thus, high prickle values of ramie, jute and wool fibres make them more uncomfortable due to the cross-section parameters and bending modulus of the single fibre needle. It is observed that the prickle feeling comes from the axial-compressive behavior and the number of effective fibre needles protruding from worn fabric surface. Therefore, prickle sensation aroused during skin-fabric contact is mostly related to the fibre and surface roughness characteristics of fabrics, and the effect of the fabric material on prickle is found to be more. [ABSTRACT FROM AUTHOR]

The present paper reports a study on the relationship between physical properties of cotton and the frictional characteristics at the fibre and yarn stages. It is observed that coarser fibres show higher coefficient of friction. With regard to yarns, coarser and more compressible yarns show higher coefficient of friction values. [ABSTRACT FROM AUTHOR]

Though finer quality fibre is of great demand in the industry, a reasonable biological assessment of the factors controlling jute fibre fineness is lacking. Our aim was to relate lignin synthesis and accumulation in the secondary wall of the fibre cells with fibre fineness by anatomical and physiological evidences. Several jute genotypes including a low lignin mutant, dlpf (INGR No. 04107) and its lignin sufficient parent (JRC 212) were grown under different growth conditions. Their cell wall morphology and cellulose, hemicellulose and lignin content of fibre were estimated. The fineness of the extracted fibre was examined gravimetrically as well as by air-flow method on individual plant basis to relate it with their chemical constituents. Effect of incident light and some plant growth regulators on glucan and lignin biosynthetic enzymes as well as fibre fineness was determined. Positive relationship between cell wall thickness and lignin and negative relationship between fibre fineness and lignin of jute fibre were established. Application of the GA biosynthetic inhibitor helped to reduce lignin synthesis and to increase fibre fineness. Genotypes with thinner cell wall and lesser lignin may be utilized in breeding for improving the fibre fineness of jute. Field application of GA biosynthetic inhibitors, like daminozide, is recommended to reduce the cell wall thickness of lignin sufficient high yielding jute varieties. [ABSTRACT FROM AUTHOR]

In jute ( Corchorus olitorius), quantitative trait loci (QTL) analysis was conducted to study the genetics of eight fibre yield traits and two fibre quality traits. For this purpose, we used a mapping population consisting of 120 recombinant inbred lines (RILs) and also used a linkage map consisting of 36 SSR markers that was developed by us earlier (Das et al. ). The RIL population was derived from the cross JRO 524 (coarse fibre) × PPO4 (fine fibre) following single seed descent. Using single-locus analysis involving composite interval mapping, a total of 21 QTLs were identified for eight fibre yield traits whereas for fibre quality (fibre fineness), only one QTL was detected. The QTL for fibre fineness explained 8.31-10.56% of the phenotypic variation and was detected in two out of three environments. Using two-locus analysis involving QTLNetwork, as many as 11 M-QTLs were identified for seven fibre yield traits (excluding top diameter) and one M-QTL was identified for fibre fineness which accounted for 4.57% of the phenotypic variation. For six fibre yield traits, we detected 16 E-QTLs involved in nine QQ epistatic interactions. For fibre fineness, four E-QTLs involved in two QQ epistatic interactions and for fibre strength, six E-QTLs involved in three QQ epistatic interactions were identified. Eight out of the 11 M-QTLs observed for the fibre yield traits were also involved in QE interactions; for fibre fineness and fibre strength, no QE interactions were observed. [ABSTRACT FROM AUTHOR]

Diallel crosses were made among eight parents with high yield potential, good fibre quality, and resistance to biotic and abiotic stresses. Twenty crosses showing high F1 mean, high gca and high gca effects for one or both parents were identified and carried forward by modified bulk method for selecting transgressive segregates. A micro plot trial was conducted with four best F7 lines along with two checks. Fibre yield, fibre percentage, and stick weight of all the four lines were higher than that of the checks. Analysis of variance revealed that differences in plant height, fibre yield, stick weight, and fibre percentage were significant. Line 2 derived from the cross combination CIJ 072 × CEX 045 was the best performer with regard to fibre yield, stick weight, and fibre % followed by line 1 derived from JRC 698 × CIJ 121. All four lines had fairly good fibre strength and fineness. [ABSTRACT FROM AUTHOR]

Quantitative as well as qualitative evaluation of microorganisms associated with piling of jute has been studied using raw jute fibre, jute fibre from laboratory bins and fibre samples collected from two jute mills (M/s Bharat Jute Mill and M/s Budge Budge Jute Mill). Bacterial population in raw C. capsularis jute is found to be in the order of 104 per gram of jute fibre and that in raw C. olitorius jute is in the order of 105 per gram of jute fibre. Bacterial population in laboratory bins is found to be in between 106 and 107 per gram of jute fibre while fungal population is in between 104and 105 per gram of jute fibre. The bacterial isolates are mostly Gram-positive rods of the genus Bacillus and fungi mainly of the genera Aspergillus and occasionally Penicillium. No significant change in strength and fineness of fiber has been observed due to 48 h of piling. Bacterial and fungal populations in piled jute samples of Bharat Jute Mill are found to be in the order of 108 and 105 per gram of fibre, while the same in Budge Budge Jute Mill are in the order of 105 and 10³ per gram of jute fibre respectively. The bacterial isolates are mostly Gram-positive rods of the genus Bacillus, Gram-positive coccus of the genus Micrococcus and Gram-positive filamentous rods of the genus Streptomyces. Fungal isolates are mainly of the genera Aspergillus and, to a lesser extent, of the genus Penicillium and Dendrophoma. Mucor has been found only in Bharat Jute Mill and Chaetomium is found only in Budge Budge Jute Mill fibre samples. Genera of bacteria and fungi isolated in jute fibre samples from both the jute mills are mostly similar which indicates that only a small group of microorganisms is active in jute bins/piles and they originate from the common source, i.e. soil and water during retting. All the isolated bacteria as well as fungi possess pectinolytic activity. This indicates that the piling microbes might play a significant role in removing residual pectin from the fibre during piling of jute. [ABSTRACT FROM AUTHOR]

Jute and kenaf are among the annually renewable fibre crops mainly grown over tropical and subtropical Asian countries. They are possibly the world's largest source of lignocellulosic bast fibre which is extracted from plants by a natural microbial process known as retting. But acute shortage of water for retting and the environmental pollution created from conventional system of retting has demanded for new method of retting. The new method of retting launched has been recognized as ribbon retting. In ribbon retting barks are removed from jute and kenaf plants mechanically or manually in the form of ribbon. The ribbons are coiled anti then allowed for retting in water with or without using a microbial inoculum. Ribbon retting has the following advantages over conventional retting: ( 1 ) It requires lesser volume of water, (2) it is faster, (3) it produces lesser environmental pollution, and (4) it produces improved quality fibre. Addition of efficient pectinolytic microbial inoculum may further boost up or improve the ribbon retting process. From the present study it is understood that inoculation of a specific mixed bacterial culture in combination with 0.5% urea as N-supplement caused faster ribbon retting of jute and kenaf. Ribbon retting conducted in cement retting tank was faster than that in polythene tank. The mixed bacterial culture in combination with urea produced stronger, finer and brighter coloured jute and kenaf fibre in comparison to uninoculated control. One hundred twenty-day-old plant was found most suitable for ribbon retting. Ribbon retted fibre with pectinolytic mixed bacterial culture in combination with urea obtained higher grade in comparison to uninoculated control. Such ribbon retted fibres produced standard and regular quality yarn. [ABSTRACT FROM AUTHOR]

Ring spinning process adds up short fibres in yarn structure. But the nature of short fibres and their length distribution completely differ from fibre fly that are deposited in cone unwinding zone and knitting zone. Fly from cotton carded yarn is basically shorter, very fine in nature and highly immature. The characteristics of fibre fly and its length distribution are almost similar in these zones. Fibre-shedding behaviour of carded yarn is studied before and after cone winding operations by changing some of the winding parameters based on three factors--three-level Box Behnken Design of Experiment. It is observed that there is an increase in average fibre-shedding (g) of individual cone samples over ring cop in most of the cases. [ABSTRACT FROM AUTHOR]

Genetic behaviour of fibre quality parameters under heat-stressed conditions clearly reflected the significant effect of heat stress on the phenotypic expression of fibre quality parameters. Results from the field experiments demonstrated that fibre quality was better among the upland cotton cultivars under non-stressed (June) regime. Fibre length, strength, uniformity and fineness were substantially high under June regime when compared with that under April (heat stressed) regime. The prevalence of significant genotype × temperature regime interaction for fibre length, fineness and strength provided another evidence for the influence of temperature regimes on the expression of fibre traits. A significant effect of heat stress on the phenotypic expression of fibre quality parameters was observed. [ABSTRACT FROM AUTHOR]

Abstract: This paper establishes a new method for estimating the single flax fibre diameter using the LaserScan instrument. The method is based on the mathematical modelling of the experimental fibre and fibre bundle width distribution and enables the flax fibre sample composition to be analysed in terms of proportions of single fibre and fibre bundles. The method can also be applied for the analysis of flax fibre fineness distribution produced by the Optical Fibre Diameter Analyser (OFDA) instrument. This method can be used as a tool for classification of flax accessions according to the estimated single fibre diameter, for evaluation of the efficiency of chemical and biochemical treatments aimed at the modification of flax fibre, and for evaluation of the suitability of flax fibre for spinning and manufacture of composites. The method was applied for the characterisation of 83 accessions from the Linum core collection produced by CGN at Wageningen, The Netherlands. The mean and standard deviation of single fibre diameter and proportion of single fibre and fibre bundles in the sample was estimated. Experimental results were in good agreement with theoretically expected relationships between the estimated mean diameter of single fibre and characteristics of fibre width distribution such as the mode and the overall average. [Copyright &y& Elsevier]

Dessication of flax at the mid-point of flowering, followed by stand-retting and high-speed decortication, yielded finer, stronger fibres with lower acid-insoluble lignin content and lighter colour than desiccation at later timings of two weeks after mid-flower and six weeks after mid-flower. Although fibres from all desiccation timings could be carded and blended with wool for spinning on woollen or worsted spinning systems, only the fine fibre from the earliest desiccated flax was suitable for carding, drawing, blending with cotton and spinning on cotton-processing systems.It was concluded that the lower lignin content at mid-flower allowed more complete retting of fibre bundles to give a higher yield of fine elementary fibres. This cotton-compatible fibre was produced at a competitive cost compared with cotton. It is suggested that further optimisation of desiccation timing may permit increased yields of cotton-compatible fibre. [Copyright &y& Elsevier]

This paper investigates the influence of the two sets of feed rollers prior to roller drafting on the physical properties of wet spun linen yarns, such as tensile properties and yarn regularity. The effect of using either a single or double set of feed rollers on the fibre fineness distribution of bleached rove was quantified using the SirolanTM Laserscan system and reported in terms of mean fibre fineness and percentage of fibre having a diameter above 30.5 microns. Comparative spinning trials using either one or two sets of in-line feed rollers were undertaken with several batches of bleached rove. The effect of spinning parameters on tensile and regularity characteristics of the spun yarns are reported and discussed. The effect of open reach as control parameter in double feed roller spinning was also investigated. Wet spun linen yarns produced via the double crushing of bleached rove with two sets of consecutive feed rollers have a higher mean tenacity than the traditional single roller feed system. [ABSTRACT FROM AUTHOR]

The length, fineness, tensile strength, and moisture absorption ability of Nettle (Urtica cannabina L) fibre were studied. The investigation revealed that most of the Urtica cannabina L fibres are within the range of 20 to 70 mm in length, with fineness ranging from 15 to 40 µm. The research indicated that compared to wool, cotton and several other bast fibres, Urtica cannabina L fibres' moisture absorption ability is higher because of its special fibre structure. The study showed that the Urtica cannabina L fibre could be an ideal replacement of some widely used natural textile fibres. Spinning trials showed that it is not practical to produce yarn with pure nettle fibre because of its smooth surface and straight form. However, blended with other suitable fibres, yarns may be successfully spun. [ABSTRACT FROM AUTHOR]

It is well known residual gum exists in degummed or retted hemp fibres. Gum removal results in improvement in fibre fineness and the properties of the resultant hemp yarns. However, it is not known what correlation if any exists between the residual gum content in retted hemp fibres and the fibre fineness, described in terms of fibre width in this paper. This study examined the mean width and coefficient of variation (CV) of fibre width of seventeen chemically retted hemp samples with reference to residual gum content. The mean and CV of fibre width were obtained from an Optical fibre diameter analyser (OFDA 100). The linear regression analysis results show that the mean fibre width is directly proportional to the residual gum content. A slightly weaker linear correlation also exists between the coefficient of variation of fibre width and the residual gum content. The strong linear co-relation between the mean of fibre width and the residual gum content is a significant outcome, since testing for fibre width using the OFDA is a much simpler and quicker process than testing the residual gum content. Scanning Electron Microscopy (SEM) reinforces the OFDA findings. SEM micrographs show a flat ribbon like fibre cross-section hence the term “fibre width” is used instead of fibre diameter. Spectral differences in the untreated dry decorticated skin samples and chemically treated and subsequently carded samples indicate delignification. The peaks at 1370 cm−1, 1325 cm−1, 1733 cm−1, and 1600 cm−1 attributed to lignin in the untreated samples are missing from the spectra of the treated samples. The spectra of the treated samples are more amine-dominated with some of the OH character lost. [ABSTRACT FROM AUTHOR]

Some structural parameters of fibre bundles, as revealed by the microscopical study of the transverse section of jute plant stems, have been found to have high positive correlations with filament fineness of extracted fibres. Equations have been derived by linear regression analysis to predict the fineness of extracted fibres. The study would not only be very helpful in selecting the fine fibre producing plants in breeding programmes, but will also provide some information on the structure -quality relationship of jute fibre, necessary for genetic upgradation of fibre quality. [ABSTRACT FROM AUTHOR]

The article discusses the possible use of the new automatic feed grip of the Almeter apparatus to test the internal structure of worsted slivers. One of the authors used the Almeter automatic grip, then at the design stage, for analysis of the variation of fibre-length distribution along a sliver. There are three forms of such a sampling grip including the grip of the Schlumberger Comb Sorter, the semi-automatic hand-driven grip of the Almeter apparatus, and the new automatic motor-driven grip of the Almeter.

A letter to the editor is presented about the measurement of the mean diameter of a blend of wool fibers through using the mean diameter of each component of the blend.

The article presents a letter to the editor concerning the variability of yield and fineness in length samples taken from bales of greasy wool.

A study is reported of the variability of yield and fineness measurements between core samples within 'unclassed' lots of Australian greasy wool. The lots taken as 'unclassed' are some consigned from the farm for bulk-classing. The variability is compared with that found in previous studies, for auction lots that had been classed. The results are discussed from the point of view of obtaining an adequate sample from lots of unclassed wool, and a comment is made on the effectiveness of wool-classing as it appears from the comparison. [ABSTRACT FROM AUTHOR]

The compressional behaviour of wool fibres at pressures ranging from medium to high is reported, and the effects on this behaviour of various fibre characteristics are determined experimentally. It is shown that the behaviour of a mass of wool fibres in compression can be adequately described by an equation of the form: d = aPb, where d is the density of the fibrous mass, P is the pressure, and a and b depend on such fibre parameters as yield, fineness, and crimp. A highly significant negative correlation is shown to exist between the percentage yield of greasy wools and the density of the fibrous mass at unit pressure, the relation being independent of fibre fineness. For scoured wools, there is a highly significant positive correlation between the mean fibre diameter and the density of the compressed mass. Although crimp and fineness are known to be positively correlated, it seems that each has a separate effect on the compressibility of scoured wool. For a limited range of man-made fibres, the compressional behaviour is similar to that of wool. [ABSTRACT FROM AUTHOR]

A geometrical model of the smallest repeating unit or structural knitted cell (SKC) of the fully relaxed 1 x 1 rib structure is proposed. This model, based on an elastica configuration, suggests that the dimensions of the SKC are independent of the yam flexural rigidity and yarn-deformative forces but are dependent on the ratio of structural-cell stitch length (lu) to yam diameter. Over the practical knitting range, however, this dependence is small. A series of four non-dimensional parameters, or u-values, is introduced to specify the dimensional properties of this structure. The average numerical values of these parameters are calculated. A comprehensive experimental analysis of fully relaxed 1 x 1 rib fabrics shows that the experimental w-values are close to those established theoretically. Full relaxation is obtained by tumble-drying the structures from a wet state for 1 hr at 70°C, this being followed by conditioning in a standard atmosphere. No felting is observed during this relaxation procedure. Empirical u-values of the fully relaxed state are found to be independent of most yam and machine variables. A small dependence on the machine-tightness factor (K) is noted, however. [ABSTRACT FROM AUTHOR]

A reappraisal of previous work on the hairiness of ring-spun yarns that the conclusions reached regarding the effect of fibre characteristics on cotton-yarn hairiness need to be revised. The observed effects can be explained by a simple hypothesis that the mean weight and mean length are the only fibre characteristics that intrinsically affect yarn hairiness. Published data are shown to be inadequate for arriving at satisfactory explanations of the way in which the spinning parameters affect yarn hairiness. The need for the measurement of the hairiness of yarns from the spinning zone and from the instantaneous surface of the cop, in addition to that from the interior of the cop, is established. Methods for these measurements are proposed. The information obtained is shown to be useful in explaining the phenomenon of yarn hairiness and particularly in accounting for the observed differences between different yams. [ABSTRACT FROM AUTHOR]

An account is given of an investigation in which air-flow measurements of fineness were made on individual core samples drawn from lots of scoured wool. From analyses of variance, estimates were made of between-bales, between-ends, and between-cores components of variance. These estimates suggest that the sampling precision (95 % confidence level) for lots of ten bales or more should be, at the worst, ±0-2 µm and may be better than ±0-1 µm for a sample consisting of two cores from each bale. An example is given in which the variability of fineness within a lot of greasy wool is compared with the variability within the same lot after it had been scoured and rebaled. [ABSTRACT FROM AUTHOR]

Studies of sampling variability relating to the measurement of yield and fineness of greasy wool have been published previously for auction lots of Australian wool in spinners-wool categories. This paper describes similar studies for auction lots of carding and inferior topmaking wools. As expected, the between-bales and within-bales variability proved higher for these wools than for the spinners wools. Nevertheless, present sampling practices are expected to give acceptable precision. [ABSTRACT FROM AUTHOR]

An account is given of an inter-laboratory trial of a method of measuring the fineness of greasy wool by means of a Wira Air-flow Fineness Meter. Eight laboratories took part in two tasks: firstly, a calibration by each laboratory of its own air-flow meter in terms of internationally standardized wools; and, secondly, the measurement of the fineness of greasy-wool core samples by means of the specified method, which included a normal laboratory washing of the wool followed by opening on a wool-type Shirley Analyser. As a result of the trial, the method was considered to be suitable for use by testing authorities, and tentative limits of precision of the method of measuring the fineness of greasy wool were established. The mean difference between any two laboratories ranged from 0.2 μm at 20-μm diameter to 0.5 μm at 28-(μm diameter. This does not include sampling errors. [ABSTRACT FROM AUTHOR]

A survey is presented of measurements of the variability of yield, vegetable-matter content, and fineness between core samples within growers' or auction lots representing a variety of types of wool from the Australian clip. The pattern can be represented, in part, by a linear relationship between the within-bale standard deviation of a particular characteristic and the mean value of that characteristic for the lot. The data presented do not suggest that a change from the present sampling schedule is necessary. [ABSTRACT FROM AUTHOR]

The air-flow fineness apparatus, long used in the measurement of the fibre diameter of wool tops, is finding a rapidly growing application in the determination of the fineness of samples of loose wool or corings. It is known that the indication of the instrument is sensitive to the arrangement of fibres in the plug and that a calibration made by using wools in the form of tops cannot be expected to hold for the same wools in a different form. This paper reports an investigation into the shift in instrument indication produced by subjecting tops to a variety of treatments: cutting, coring, hand-and machine-washing, and passage through the Shirley Analyser. The treatments were applied singly or in certain combinations. In all cases, the treatment produced an apparent increase in mean fibre diameter, i.e., increased air-permeability, the magnitude of the increase rising with mean diameter. The change in apparent diameter is considered to arise from an increase in pore-size distribution in the fibre mass, which is the result of disordering the fibre arrangement. Disordering can be caused by various treatments. The effect of a steaming treatment on tops was somewhat similar to that produced by the other treatments already mentioned. The magnitude of the apparent shift in diameter is tabulated for the important cases. [ABSTRACT FROM AUTHOR]

A comparison is reported of fineness results obtained for 27 lots of scoured wool by the projection-microscope and air-flow methods. The sampling of the scoured wool was done by core-boring, and the cores were hand-carded before air-flow tests were made. The sub-samples for projection-microscope measurement were cut into snippets 1 mm long in order to obtain a length-biassed sample. The air-flow apparatus was calibrated with reference tops in five different forms. The results show that there exists a systematic difference between the air-flow and projection-microscope mean diameters of scoured wool when the air-flow instrument is calibrated with reference tops in the original state. A better agreement results by hand-carding the test samples of the reference tops, but the closest agreement is obtained by cutting, washing, and hand-carding these test samples so that their condition is similar to that of the core sample being tested. Provided that this kind of calibration were applied, the mean diameter of washed wool could be determined by air-flow testing of cored and hand-carded samples. [ABSTRACT FROM AUTHOR]

A satisfactory procedure has been found for determining with an air-flow meter the mean fineness of greasy wool sampled from bales by pressure-coring. A wool-model Shirley Analyser is used to remove dirt and vegetable matter from the washed wool cores. The Analyser also intimately mixes the wool fibres of a sample, which substantially improves the precision of the air-flow measurement. The effect of the Analyser on the measured value of fineness is investigated, and possible methods of calibration of the air-flow meter for use on wool cores are considered. A series of measurements on greasy-wool cores by both air-flow and projection-microscope methods is used as a basis for the suggested procedure. The precision of measurement is evaluated, and a particular calibration method is recommended. The mean fineness of a sample of greasy wool in core form can be found with a precision of ± 0 5 µm. [ABSTRACT FROM AUTHOR]

Differences between the results obtained for the fineness of wool tops measured by air-flow and projection-microscope methods can arise because the coefficient of variation of the measured top is different from that of the tops used to calibrate the air-flow meter. The validity of some assumptions implicit in the air-flow calibration is examined and a correction table for precise use of the air-flow meter calculated. The corrections range from ♂2% at 16 µm to zero at 36µm. [ABSTRACT FROM AUTHOR]

A survey has begun of the components of variance of yield (oven-dry wool content), vegetable matter, and fineness of Australian wool in auction lots. Some initial results, referring to AWB wool types 413 and 40, are presented and discussed. These types are among those most frequently occurring in the Australian clip and together account for about 10% of the clip. The results indicate that, if all bales in a lot are sampled with a pressure-coring device, two such samples being taken from each bale, the precision of the lot mean yield for lots of five bales or more is 1% or better and the precision of the lot mean fibre diameter is 0 4 (im or better. For fineness determination, a significant variation was found between the ends of a bale, and this suggests that both ends of bales should be sampled. [ABSTRACT FROM AUTHOR]

A method is described whereby the shrinking property of wool can be modified during growth by the administration of chemical additives to the sheep's diet so as to enter the character of the fibre half-way through the growth of the staple. Thus, hard-root-soft-tip fibres can be grown to enhance shrinkage and soft-root- hard-tip fibres to impart shrink-resistance. Methods of modifying the shrinkage of wool have so far been confined to chemical treatments of the shorn fibre, but this original approach to shrinkage control also presents an opportunity for the mass production of a large variety of other types of special-purpose wools. [ABSTRACT FROM AUTHOR]

Needled fabrics are complicated structures, and an exact analysis of their mechanics is not yet possible. Understanding is approached through three routes. Firstly, the behaviour of a fully bonded web is used to predict the effects of orientation, and to estimate the upper limits of strength. These estimates may be reasonable if the network that actually exists at the breaking point is used in calculations. Needled fabrics can give a fairly high utilization of fibre strength. Secondly, the effects of slippage are discussed qualitatively, by analogy with the behaviour of spun yams. The influences of entanglement, fibre length, fibre fineness, and fibre friction are discussed. Thirdly, a quantitative analysis, with many approximations, of a much-simplified model is made. Despite the unsatisfactory nature of some of the assumptions, the predictions are in general accord with experimental results. [ABSTRACT FROM AUTHOR]

An account is given of an investigation of the effects of fibre type (rayon, acrylic fibre, wool, and cotton) and dimensions on the properties of needled fabrics, the test methods used being those described in a previous paper. Some fabrics show a stick-slip behaviour in extension; others deform smoothly. Rayon webs — consolidate more easily on needling than Courtelle or wool webs. Longer fibres give higher fabric strengths. Finer fibres also give higher strength, unless fibre damage occurs. The influence of fibre friction is discussed. [ABSTRACT FROM AUTHOR]

An account is given of air-flow experiments with paraIlel-fibre plugs of jute and mesta (kenaf). Over the working range of packing density of 0-4-0'6 g/cm², the Kozeny equation was found to be approximately true. The dependence of κ on the porosity, ε, was examined and κ was found to be slightly low for white jute. The effect of combing on k was small. Random-fibre plugs were unsuitable. On the basis of these observations, a simple direct-reading fibre-fineness tester with a constant-flow aspirator, suitable for use in Indian rural areas, has been developed for jute and mesta. [ABSTRACT FROM AUTHOR]

A new electronic jute fibre fineness meter has been developed with the aim to replace the manual air-flow fineness meter in order to eliminate the possible human error. This instrument is based on a microprocessor, pump motor and pressure sensors. It provides automatic results in 'tex' for the fibre under test. This handy instrument can also be used for other fibres by changing system parameters. [ABSTRACT FROM AUTHOR]

IWTO Core-test Regulations define the core sample that must be taken for yield measurement on a lot of greasy wool. On the basis of studies of fineness variability between and within bales, the expected sampling precision for mean fineness is calculated on the assumption that the same sample is used as a source of test specimens to be measured by a proposed modification of the air-flow-fineness method. Under present regulations, the expected precision is acceptable; it is emphasized, however, that, if core samples are to serve a dual purpose, variability of both yield and fineness must be considered in drawing up sampling schedules. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the separate letters by R. K. Mann and S. L. Anderson and G. E. Settle about the calibration of air-flow meters for wool, which both appeared in the previous issue of the periodical.

A letter to the editor is presented in response to the article about the measurement of fiber dimensions using the microscopical semi-automatic method.

A letter to the editor is presented regarding the moisture effect on the jute-fibre fineness determined by the air-flow method.