Optical Fibre Diameter Analyser Research Articles

Effect of mordants on colour variation in alpaca fibre dyed with dye extracted from the tankar stem (Berberis boliviana L.)

AbstractThe objective of the research was to evaluate the effect of mordants on colour variation, textile characteristics, colour fastness, and Fourier‐transform infrared (FTIR) bands in alpaca fibre dyed with tankar stem extract. The white alpaca fibre was obtained from the company Inka Tops S.A. The mordants used were: alum (KAl(SO4)2·12H2O) at 20% and iron(II) sulphate (FeSO4) at 3%. Prior to dyeing, a pre‐mordanting process was carried out (86°C for 30 min), and dyeing was performed through thermal treatment at 70 and 86°C (30 and 60 min). The CIELab [L*, a*, b*, chroma (C*) and hue (h°)] coordinates and reflectance were evaluated using a spectrometer; textile characteristics were assessed with OFDA (optical fibre diameter analyser) 2000; chemical bands were analysed with an FTIR‐attenuated total reflectance (ATR) spectrophotometer, and colour fastness (light, washing, and rubbing) was evaluated using international American Association of Textile Chemists and Colorists (AATCC) standards. The results showed that luminosity (L*) significantly decreased after dyeing and pre‐mordanting with KAl(SO4)2·12H2O (81.47) and FeSO4 (70.47). Additionally, the b* value and C* value significantly increased at higher temperature and longer dyeing time, resulting in slightly different shades and hues in each treatment. The coefficient of variation (CV) and curvature index (CU) presented significant differences, with CU increasing at 86°C/60 min with FeSO4. Colour fastness to washing and rubbing showed acceptable values on the greyscale. In conclusion, the mordants used had a significant effect on colour variation, textile characteristics, colour fastness, and FTIR spectrum. The most intense shades were observed in fibres pre‐mordanted with FeSO4 (dull yellow‐green) and in dyeing without mordant (yellow).

Development and validation of a smart system for medullation and diameter assessment of alpaca, llama and mohair fibres

Medullated fibres, due to their higher resistance to bending and pressure, constitute a problem for the textile industry. Thus, having practical instruments to identify them is essential. Therefore, the aim of this research was to develop and validate a novel, swift, automatic system (referred to as S-FiberMed) for medullation and diameter assessment of animal fibres based on artificial intelligence. The medullation of 88 samples of alpaca, llama and mohair fibres (41, 43 and 4, respectively) was evaluated. Additionally, 269 samples of alpacas were considered for average fibre diameter (AFD) and the results were compared with the Portable Fiber Tester (PFT) and Optical Fibre Diameter Analyser (OFDA) methods (72 and 197 samples, respectively). The preparation of each sample to be analysed followed the procedure described in IWTO-8-2011. Version 5 of “You Only Look Once” and DenseNet models were used to recognise the type of medullation and diameter of the fibres, respectively. Within each image (n = 661 for alpaca), all fibres were labelled (as Non-Medullated, Fragmented Medulla, Uncontinuous Medulla, Continuous Medulla and Strongly Medullated) using the LabelImg tool. Data augmentation technique was applied to obtain 3 966 images. Such data set was divided into 3 576 and 390 images for training and test data, respectively. For mohair samples (n = 321), a similar process was carried out. The data to train the model used to infer the diameter contained 16 446 fibres labelled with his respective AFD. A complementary hardware composed of three subsystems (mechanical, electronic, and optical) was developed for evaluation purposes. T-test, Pearson and Concordance correlation, Bland-Altman plot and linear regression analyses were used to validate and compare the S-Fiber Med with other methods. Results indicate that there was no significant difference between medullation percentage obtained with the projection microscope and the S-Fiber Med. The Pearson and Concordance correlation analysis shows a strong, high and significant relationship (P-value < 0.001). The AFDs of alpaca and llama fibre samples obtained with the two methods are very similar, because no significant difference was found at the t-test (P-value > 0.172), and they have a strong, high and significant relationship between them, given the high Pearson correlation value (r ≥ 0.96 with P-value < 0.001), high Concordance coefficient and bias correction factor. Similar results were found when PFT and OFDA100 were compared with S-Fiber Med. As a conclusion, this new system provides precise, accurate measurements of medullation and AFD in an expeditious fashion (40 seconds/sample).

Comparison of Genome-Wide Association Scans for Quantitative and Observational Measures of Human Hair Curvature.

Previous genetic studies on hair morphology focused on the overall morphology of the hair using data collected by self-report or researcher observation. Here, we present the first genome-wide association study (GWAS) of a micro-level quantitative measure of hair curvature. We compare these results to GWAS results obtained using a macro-level classification of observable hair curvature performed in the same sample of twins and siblings of European descent. Observational data were collected by trained observers, while quantitative data were acquired using an Optical Fibre Diameter Analyser (OFDA). The GWAS for both the observational and quantitative measures of hair curvature resulted in genome-wide significant signals at chromosome 1q21.3 close to the trichohyalin (TCHH) gene, previously shown to harbor variants associated with straight hair morphology in Europeans. All genetic variants reaching genome-wide significance for both GWAS (quantitative measure lead single-nucleotide polymorphism [SNP] rs12130862, p = 9.5 × 10-09; observational measure lead SNP rs11803731, p = 2.1 × 10-17) were in moderate to very high linkage disequilibrium (LD) with each other (minimum r2 = .45), indicating they represent the same genetic locus. Conditional analyses confirmed the presence of only one signal associated with each measure at this locus. Results from the quantitative measures reconfirmed the accuracy of observational measures.

Fibre characteristics of vicuña ( Vicugna vicugna mensalis)

Characteristics of body and fleece weight, and fleece and fibre quality were evaluated in vicuñas ( Vicugna vicugna mensalis) captured for live shearing in Huancavelica, Peru. A total of 305 animals were weighted and shorn between 2003 and 2008. Fibre samples from 104 animals shorn in 2008 were analysed using optical fibre diameter analyser (OFDA) and fibre length measured in a subsample of 68 animals. Mean values for body weight, fleece weight, fibre length and fibre diameter were 37.8 kg, 189.7 g, 30.9 mm and 13.2 μm respectively. Differences due to age were significant for body weight, fleece weight and fibre diameter, but no differences were attributable to sex. The average coefficient of variation of mean fibre diameter was 19.5% showing a higher homogeneity than other luxury animal fibre producers. Mean fibre curvature was medium (79.9°/mm) showing a low relationship with fibre diameter.

A method of estimating the single flax fibre fineness using data from the LaserScan system

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.

Genetic and non-genetic factors influencing fibre quality of Bolivian llamas

Fibre samples of 2378 llamas were analysed with the optical fibre diameter analyser (OFDA). The following traits were considered: mean fibre diameter (MFD), standard deviation (S.D.), diameter of fibre <30 μm (DF < 30), proportion fibre <30 μm (% F < 30), proportion of kemp (PK) and proportion of medullated fibre (PMF). The effects of type of llama, age, sex and coat colour were studied. The type of llama influenced all traits showing that Th’ampulli (fibre type) is better than Kh’ara (meat type). With increasing age of the animal MFD, S.D., DF < 30 and PK increased whereas % F < 30 decreased. Comparing the two sexes, females showed better fibre quality. Heritabilities and genetic correlations for fibre traits were estimated using animal model procedures where all information came from mother–offspring relationships. Heritability estimates were 0.33, 0.28, 0.36, 0.32 and 0.25 for MFD, S.D., DF < 30, % F < 30 and PK, indicating potential for genetic selection. Genetic correlations between fibre traits and some body measurements were also calculated. In conclusion, the llama population studied shows a high genetic potential for high quality fibre production. The information available allows further steps towards the design of a breeding program.

Increasing the profitability and sustainability of grazing enterprises in northern NSW by comparing different input and grazing management systems

The Cicerone Project has been set up to study the long term profitability and sustainability of 3 different input and grazing management systems. Farm A receives high inputs of sown pastures and fertiliser, and uses flexible rotational grazing, with 8 paddocks and 4-5 mobs of livestock. Farm B receives medium inputs of fertiliser, but uses similar grazing management and paddock allocations to Farm A. Farm C receives the same medium level of inputs as Farm B, but employs intensive rotational grazing involving long rest periods between grazings. This farm has 33 paddocks and livestock mobs are combined to no more than 3 mobs to increase the grazing pressure.Livestock are weighed regularly; ewes are scanned for twins; parasite burdens are monitored; wool characteristics are measured for all sheep, e.g. fleece weight, Optical Fibre Diameter Analyser (OFDA) for micron and diameter profile along the staple length and Australian Wool Testing Authority (AWTA) test for tensile strength. Pastures are assessed monthly and each time stock are moved, and carrying capacity (dse) and grazing days per paddock are recorded. Soil tests are conducted prior to fertiliser application. Economic data on each farm have been collected and include all inputs such as labour, seed and fertiliser, fencing, agistment, animal health products and supplementary fodder.Data have been collected since July 2000 when the different management treatments commenced. Already there are marked differences between the farms in the animal weights, breeding performance, wool characteristics, botanical analysis, parasites and economic performance.

Correlating the fineness and residual gum content of degummed hemp fibres

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.

Measurement of medullation in wool and mohair using an Optical Fibre Diameter Analyser.

We conducted three experiments to evaluate the Optical Fibre Diameter Analyser (OFDA) for estimating medullation (med [M], kemp [K], and total [T] medullated fiber content) in mohair and wool produced by Angora goats and sheep, respectively. Medullation can be a beneficial characteristic in certain types of wool, but it is highly undesirable in mohair and apparel wools. Current techniques for evaluating medullation in animal fibers are laborious, slow, and expensive. The OFDA had been modified by the manufacturer to measure fiber opacity distribution, a characteristic known to be indicative of medullation in white fibers, and was capable of providing such measurements in a very short time. Measurements made on magnified fiber images produced with a projection microscope (PM) were used as a reference for M, K, and T in fiber samples. An initial experiment with 124 mohair samples (T = .10 to 9.10%) seemed to indicate that OFDA estimates of M, K, and T were only poorly correlated with corresponding PM values (r2 = .5409, .1401, and .5576, respectively). However, a second experiment using wool and mohair samples containing a wider range of medullation (T = .58 to 26.54%) revealed that OFDA estimates of M, K, and T for wool were highly correlated with PM measurements (r2 = .9853, .9307, and .9728, respectively). Evidence was also obtained indicating that the low r2 values associated with mohair relationships were likely due to a combination of factors: 1) high variation among the standard PM measurements and 2) the relatively low M, K, and T contents of the mohair samples compared with wool. In a third experiment, greater accuracy was obtained in the PM measurements by evaluating many more individual fibers per sample (10,000). In this case, OFDA estimates of M, K, and T for mohair were highly correlated with corresponding PM measurements (r2 = .8601, .9939, and .9696, respectively). However, the two sets of linear regression equations obtained for wool and mohair were somewhat different, indicating that separate calculations should be used to estimate PM measurements from OFDA data. In conclusion, it was demonstrated that the OFDA instrument is capable of providing relatively fast, accurate, and potentially less expensive estimates of medullated fiber characteristics in mohair and wool.

Measuring the Diameter Profile of Single Wool Fibres by Using the Single Fibre Analyser (SIFAN)

An instrument named the Single Fibre Analyser (SIFAN) was built to measure the diameter profile of single wool fibres. By scanning every 40 μm along the length of a 100-mm fibre, a detailed diameter profile of a fibre could be measured in less than 2 minutes. The measurement error of the SIFAN was low (s.d. = 0.6 μm) in view of the large variation in diameter over relatively short lengths of fibre. Fibre-diameter profiles measured along single fibres by the SIFAN were compared and correlated closely with single-fibre and 2-mm-snippet profiles measured with the Optical Fibre Diameter Analyser.

Opportunities for the simultaneous estimation of essential fleece parameters in raw cashmere fleeces

Abstract Two models for the simultaneous estimation of fibre quality and yield in non-separated raw cashmere fleeces based on the Wildman/Bray-formula and the application of the optical fibre diameter analyser (OFDA) are described. The first model is based on length-biased cashmere subsamples; thus, this model requires the application of a minicore sampler. If there is no minicorer available, the second model can be used which is associated with higher measuring and calculating efforts (measurement of down fibre and guard hair length). To check the applicability of these models, 18 raw cashmere fleece samples (first model) and 30 simulated cashmere fleece samples with defined fibre length (second model) were evaluated for mean fibre diameter and cashmere weight. The samples were analysed by means of the OFDA; the resulting fibre diameter distributions given in a histogram were separated into a down fibre and a guard hair distribution. Additionally, the effect of different separation criteria for distinguishing between down and guard hairs, one fixed (down fibres 4–30 μm) and two ‘more objective’ criteria (fitting of a Gaussian normal and a lognormal distribution to the down fibre peak), on the yield and quality evaluation was investigated. It is shown that the most accurate evaluation of the cashmere quality can be realised whilst using the first ( r = 0.930) and second separation criteria ( r = 0.932). Strong and highly significant correlations between the actual cashmere yield and the OFDA-estimated yield values were obtained for the three separation criteria in the first model ( r = 0.970, 0.970 and 0.968). There were no significant differences between the three separation criteria. Thus, it is not necessary to use one of the ‘more objective’ criteria for the cashmere yield and quality evaluation, which requires a higher calculating effort than the first criterion. To reduce the calculating efforts in a further step, the mean specific gravity of the guard hairs can be used for the yield evaluation instead of the fleece-specific guard hair density. The second model yields also a respectable result, however, the simulated fleece samples did not require the calculation of fibre length. A high and significant correlation coefficient of r = 0.952 was calculated between the actual and OFDA-based cashmere yield.

Measurement of cashmere yield and mean fibre diameter using the optical fibre diameter analyser

A new technique was developed to measure the yield and mean fibre diameter of cashmere. The fibre diameter distribution of 2-mm snippets measured by the Optical Fibre Diameter Analyser (OFDA) was used to calculate cashmere yield of a goat fleece without dehairing. The total volume of fibres &lt;35 and &gt;35 �m was then calculated from the diameter distribution, and from this it was possible to predict the cashmere yield of 6 standards ranging from 10 to 60% yield (r2 = 0.98, n = 30). In addition, the Shirley Analyser was compared with the OFDA technique for measuring cashmere yield (r2 = 0.59, n = 110). OFDA estimates of cashmere yield were on average 10% higher (standard deviation � 7%) than those of the Shirley Analyser, indicating poor agreement between the 2 techniques. This is likely to be due to the Shirley Analyser and OFDA estimates of cashmere yield being affected by different fibre properties of the fleeces. There was good agreement between the Fibre Diameter Analyser (FDA) and the OFDA for measuring mean fibre diameter (MFD) of dehaired cashmere samples (r2 = 0.97, n = 108). There was also a good agreement in estimates of cashmere MFD between whole fleece and dehaired cashmere samples measured by the OFDA (r2 = 0.97, n = 77). Calculation of cashmere yield and down MFD by the OFDA has shown it to be accurate for measuring standard samples, and as precise as the Shirley Analyser. Therefore, the use of the OFDA is a potential low cost alternative to rank the value of cashmere goats for breeding.

Evaluation of the optical fibre diameter analyser (OFDA) for measuring fiber diameter parameters of sheep and goats.

The Optical Fibre Diameter Analyser (OFDA) instrument is based on automatic image analysis technology and was recently introduced to provide a rapid, accurate measurement of average fiber diameter (AFD) and diameter distribution (SD) of textile fibers. Experiments were conducted with wool and mohair in various physical forms (top, core, and staple) to compare results produced by the OFDA with two other methods of determining fiber diameter parameters: the standard projection microscope (PM) method as described by the American Society for Testing and Materials (ASTM) and the Peyer Texlab FDA 200 System (FDA200). The results show that the OFDA fiber diameter measurements were very closely related to PM measurements, and the OFDA partially overcame one shortcoming of the FDA200, overestimation of SD. The results suggest that the OFDA is a promising system for rapid and accurate evaluation of fiber diameter and its distribution.