Merino Wool Fibers Research Articles

Intelligent Identification of Chinese and Australian Merino Wool Fibers Based on Image Recognition

In order to promote the sustainable growth of the wool industry and protect consumers' legitimate rights, rapid identification of the country of origin for wool of the same type is deemed crucial. This research presents a computer graphic recognition training model that utilizes median and Wiener filtering techniques to effectively reduce noise in the raw wool fiber images. Employing a support vector machine as the classifier and integrating a polynomial kernel function, this model achieves swift and accurate identification of Chinese and Australian Merino wool fibers. Experimental results underscore that following image recognition training, the model attains an impressive 92.5% comprehensive and precise identification rate for Chinese and Australian Merino wool fibers, effectively distinguishing the origin of wool from the same category. This approach not only provides a valuable reference for identifying the origin of similar wool types but also holds the potential to standardizing the wool fibre material market and assuring the consumer’s confidence on wool products.

Eco‐friendly approach on wool pretreatment and effect on the wool structure and dyeability

AbstractThis research investigated the effect of various proteolytic enzymatic pretreatment on morphological and chemical features and the dyeability properties of wool fibres. Scoured merino wool fibres are treated with protease, papain, trypsin, and pepsin in specified conditions. Each enzyme activity measurement was provided by appropriate methods such as Bradford, BAPNA (N‐benzoyl‐1‐arginine‐p‐nitroanilide), and BSA (Bovine Serum Albumin). Enzymatic processes were carried out for 24 h in the incubator set at 40°C, 100 rpm, and specified pH with 1 mg/ml enzyme concentration. Whiteness index (Stensby) and yellowness index (ASTM D 1925) were examined after enzymatic pretreatment. Pepsin and trypsin‐treated wool fibres showed the highest whiteness index as 61.3 and 61.1, respectively whilst untreated wool fibres had 52.2. Fourier‐transform infrared (FTIR) analysis revealed the increase in the intensity of amide‐related bands and hydroxyl bands after enzymatic treatment. Scanning electron microscopy (SEM) photomicrographs manifested the cuticle layer is partially removed in enzyme‐treated fibres. Elemental identification was provided by SEM–energy‐dispersive X‐ray spectroscopy (EDX). It appears that the sulphur bonds decreased after the treatment and the pepsin‐treated fibres have fewer bonds of all. To examine the damage to the structure, photomicrographs were taken using fluorescence and light microscopes. The alkali solubility test (ASTM D1283) was also conducted to compare different enzyme types. Wool fibres were dyed in 2.0% concentration with reactive dyestuff. Dyeability and colorimetric features of fibres were measured by a spectrophotometer. The washing fastness test showed that all the samples have good results and the colour change after washing was better in enzyme‐treated samples (grade 5) compared to untreated wool fibres (grade 4–5).

Ecological application of natural biomaterial on natural fibres

Circular economy calls for circular materials implemented at each stage of input for zero waste output including textile wet processing. Thereby combating global climate and human health crises attributed to textile emissions and effluents. UN Sustainable development goals promulgate sustainable resource applications throughout the manufacturing chain hence the envisaged research. Natural biomaterials (Herbs) such as indigo, manjistha, cinnamon herb, green tea, kesudo, goldenrod herb, neem, and tulsi were sustainably applied on bamboo, banana, and merino wool fibres. The surplus bath dissolved oxygen level was 6.80, 7.81 and 7.21 mg/l after processing with kesudo herb, cinnamon herb, and goldenrod herb respectively hence ecological. The ORP was increased from −53.4 mV of the original water to +54.2, + 59.0, and + 57.8 after processing with kesudo herb, cinnamon herb, and goldenrod herb respectively. Therefore, the spent solution could be readily renewed or upscaled. The ATR-FTIR demonstrated strong peaks of carbon-to-carbon triple bond in raw kesudo herb and merino wool yarns treated with kesudo herb at the wavenumbers 2125.12 cm−1 and 2124.84 cm−1 respectively and whereas in raw cinnamon herb and its treated merino wool yarns at the wavenumbers 2116.37 cm−1 and 2117.35 cm−1 respectively. Consequently, functionally valuable results were acquired. The b* values gained with kesudo herb were 68.61, 22.06 for cinnamon herb, and 37.25 for goldenrod herb indicating yellow colour tone obtained on the treated merino wool yarns. The wash fastness rating obtained were good to excellent. Evaluation of functional properties and life cycle analysis is recommended for future work.

Sustainable Processing with Herbs on Bamboo, Banana, and Merino Wool Fibers

ABSTRACT To refute the global catastrophe owing to emissions and effluents from the textile wet processing units, with sustainability at fore, the research herein performs the processing of natural fibers with herbal materials for coloration and to add functionality. Biodegradable fibers bamboo, banana, and merino wool were contemplatively considered for treatment with surplus plant-based materials, namely, mango ginger, alkanet, henna, cloves, munro, chilly, birch, goldenrod, poplar, and walnut. An organic process was developed for the extraction and application of natural biomaterials on natural fibers for sustainable outcomes. The dissolved oxygen (DO) level and oxidation-potential level (ORP) were highest with cloves at 7.91 mg/l and 84.0 mV, respectively. The maximum K/s values obtained for mango ginger, cloves, and henna were 26.43, 23.23, and 28.53, respectively. The wash fastness ratings and the lightfastness ratings were best obtained with merino wool yarns treated with cloves. The ATR-FTIR demonstrated cloves and merino wool yarns treated with cloves as the most condensed in functional groups, namely, alcohol O-H bonds, C = C aromatic carbonyl group, and carbon to nitrogen triple bonds followed by mango ginger and henna. Evaluation of functional properties such as anti-microbial will be carried out further.

Instrumental characterization of merino wool fibers dyed with Cinnamomum camphora waste/fallen leaves extract: An efficient waste management alternative

The present study describes the use of Cinnamomum camphora waste/fallen leaves as an eco-friendly natural colorant for developing colorful and antibacterial wool fibers in view of growing environmental pollution and increasing needs for biomedical textiles in healthcare sector. Extraction of the natural colorant from C. camphora reddish colored/middle-aged waste/fallen leaves was carried out via simple water bath and ultrasound water bath extraction methods. While optimizing the colorant extraction in an aqueous solvent, ultrasound water bath provided enhanced extraction efficiency at pH 3, temperature of 70 °C, an initial dose level of 1.0 gm/50 ml of H2O, time of 80 min, and ultrasonic frequency of 80 kHz. Phytochemical analysis of extracted dye was successfully carried out using simple qualitative experimental analysis. The extracted colorants from C. camphora waste leaves were used to dye merino wool fibers through exhaustion dyeing technique. The optimal dyeing conditions, dye performances, and the ultrasonic effects were reported effectively. Build-up properties and fastness characteristics were studied in the presence and absence of mordants under corresponding ISO standards. Increasing ethanol concentration, increased discoloration properties of dyed wool fiber. Dyeing kinetics and dyeing rates under both simple water bath and ultrasound water bath conditions were compared. The structural and thermal changes in the dyed fibers under both conditions were analyzed using FT-IR, TG, and SEM analysis. An adequate amount of C. camphora leaves extract on wool fiber exhibited good antibacterial behaviors with high durability to increasing number of washing cycles. Premordanting with Cu2+, Fe2+, and Al3+ salts had a slightly negative effect on the antibacterial activity of dyed wool fibers but showed enhanced durability. Camphor waste leaves will prove great potential for industrial application as a source of natural colorant, as well as a value-adding application (biomedical textile) in addition to its normal usage.

Fibrous keratin protein bio micro structure for efficient removal of hazardous dye waste from water: Surface charge mediated interfaces for multiple adsorption desorption cycles

For the first time we report fabrication of a keratin protein based bio material for efficient removal of hazardous dye waste from water using merino wool fibers. Surface hydrolysed keratin protein fibers were prepared by subjecting merino wool fibers to controlled hydrolysis. During the hydrolysis the cuticle cells which sheath the hierarchical microstructure of the wool fibers were denatured. This has resulted in exposing ortho cortex of the fibers with comparatively higher degree of free amine and other surface functional groups which were confirmed by the SEM, EDX, AFM, FT-IR, NMR and CHNS analysis. The material showed exceptional adsorption capacities for carcinogenic Rhodamine B dye in the presence of acetic acid. Under optimized conditions, the surface hydrolysed keratin protein fibers showed ~95% of dye adsorption with maximum adsorption capacity of 294 mg/g at 298 K, in the presence of 3.5% acetic acid. This is the highest reported for the Rodhamine dye adsorption at similar conditions using other dye adsorption methods. Adsorption isotherm studies and Scatchard analysis of the isotherms were carried out to understand the binding mechanism of the dye molecules to the keratin protein fiber material. The main chemical attractions were found to be due to the free amine and carboxylic functionalities presence in the hydrolysed wool fiber material. Also it was observed to have charge induced adsorption and desorption which were driven mainly due to the protonation and deprotonation of the amine groups present in the keratin protein fibers. It is also confirmed that keratin protein fiber can be used for multiple times for adsorption of the dye molecules from an aqueous medium. Combining the high adsorption capacity and recyclability, surface hydrolysed keratin protein fibers prepared from merino wool can be a promising bio material to remove Rhodamine B dye from an aqueous medium modulated by acetic acid.

Natural dyeing of merino wool fibers with Cinnamomum camphora leaves extract with mordants of biological origin: a greener approach of textile coloration

In this research work, an attempt has been made to investigate the possibility of wool dyeing with natural dye extracted from the Cinnamomum camphora middle aged/mature leaves. Visually, a range of ecofriendly shades with quite different color gamut of varying hue and tone were produced via the application of different natural mordants. The effect of various natural mordants (gallnut, pomegranate peel, arjun bark, chlorophyll extract, and citric acid) and some commonly used metal mordants (ferrous sulfate, copper sulfate, stannous chloride, and sodium dichromate) on color and fastness properties of dyed wool samples was comparatively evaluated in conjunction with 50% (o.w.f.) of C. camphora natural dye. Dyeing experiments were performed with and without mordants employing pre-mordanting technique. The color of dyed wool fibers were investigated in terms of CIELab (L*, a*, and b*) and color strength values (K/S); and fastness properties were determined as per ISO standard test methods. In general, pre-biomordanted wool fibers with P. granatum (3, 4 and 5% o.w.f.), citric acid (5% o.w.f.) and chlorophyll extract (10–50% o.w.f.) showed comparable color and fastness results compared to those of metal treated samples. Durability of color was also checked to assess the effect of washing of dyed wool fibers. This research work on the use of ecofriendly biomordants will provide a valuable reference in future for ecological and environmentally safe dyeing.

Application of kulkote temperature regulating phase change material on merino wool fiber and pashmina wool felt material

Heat transfer and storage is one of the important thermal property that substantially varies due to the nature of scaled fibers coupled with layering technique applied while designing a winter garment. The presence of scales is not evenly distributed in size and numbers over the fiber surface resulting in uneven heat flow or trapping heat released from the body. In this study the SEM images of fibers are used to characterize scale configurations, geometry, dimensions, orientation and shape of scales of merino wool, pashmina and angora fibers. However, to improve the heat retention and lower the heat flow from the fibers, kulkote phase change material is applied by spray method on the fiber felts and evaluated for its thermal properties using DSC thermograms. DSC thermograms shows the thermal behaviour of fibers before and after treating with phase change material, hence justifying the effectiveness in controlling flow of heat resulting in construction of superior winter wear products

Electron microscopy and tomography reveal that sodium 2-naphthalene sulfonate incorporated into perming solutions swells and tilts trichocyte intermediate filaments causing straightening of curly Japanese human hair.

A new hair-care process has been specifically developed for the straightening of curved Japanese woman's hair . The process included sodium 2-naphthalene sulfonate (SNS) in the reduction and oxidation steps of a conventional perming process. Our objective was to develop an understanding of how this process caused hair straightening by measuring the changes to morphology and ultrastructure between untreated, conventionally permed and SNS permed hair. Untreated and SNS permed Merino wool fibres were used to confirm structural changes. Japanese hair samples were measured for single-fibre curvature before and after perming treatments. A silver staining method was developed to stain hair fibres without changing fibre curvature so that transmission electron microscopy could be used to measure changes in the lateral dimensions of all structural components from the cellular to protein filament level. Electron tomography determined intermediate filament slopes and slope changes after SNS perming relative to the central longitudinal axis of the fibre. SNS perming was found to cause greater lateral swelling than conventional perming of: the paracortical cells of wool; the cuticle, the cuticular cell membrane complex and the macrofibrillar centre-to-centre distance of hair; and of the intermediate filaments in wool and hair. In curved hair, SNS perming caused the intermediate filaments of the helical macrofibrils to simultaneously swell and to tilt further, resulting in the slight longitudinal contraction of the macrofibrils. The overall swelling and tilting was greatest in the helical macrofibrils of Type B cortical cells predominately located in the convex fibre half. The presence of a higher percentage of helical macrofibrils in the convex fibre half than in the concave fibre half caused a contraction differential between the two halves leading to straighten of the curved fibre. A mechanical model was proposed to explain how SNS perming straightened curly hair. The effects of conventional and SNS perming on the morphological and ultrastructural components of curved Japanese hair and high-curl Merino wool fibres have given clear insights into understanding the mechanism of fibre curvature change.

Activated carbon powder derived from cashmere guard hair

Converting waste fiber to high value-added carbonaceous materials has been considered as an effective and affordable route in response to the increasing volume of waste fiber in recent year. In this study, we are the first to prepare activated carbon powder derived from cashmere guard hair as a renewable waste protein fiber, using a chemical activation method at different impregnation ratios of K2CO3/cashmere guard hair char and activation temperatures ranging from 400℃ to 600℃. Characterization of the activated carbon powder was carried out by morphology study, specific surface area study, and adsorption study. Results have shown that the increase of the impregnation ratio and the activation temperature created more microporous structure in the activated carbon powder, and then increased the specific surface area of the activated carbon powder as well as the amount of methylene blue adsorbed. However, the carbon yield increases with the increase in the impregnation ratio of K2CO3/cashmere guard hair char and decreases with the increase in the activation temperature. The activated carbon powder, activated by the condition of 1:2 K2CO3/cashmere guard hair char impregnation ratio and 600℃ activation temperature, has a specific surface area of 764.86 m2g−1 and a carbon yield of 14.07 wt%. Compared to the activated carbon powder derived from fine merino wool fibers, the activated carbon powder derived from cashmere guard hair has higher carbon yield, surface area, and total pore volume, showing a superior adsorption performance.

A Study on Extraction and Characterization of Keratin Films and Nanofibers from Waste Wool Fiber

ABSTRACTFabrication and characterization of keratin films extracted from waste Merino wool fiber using two different methods and three different pH concentrations is the main focus of this study. Also, wool keratin (WK) loaded polymer surfaces were fabricated. The chemical, structural and morphological characteristics of keratin extracted from aqueous solutions were analyzed and compared for both methods. It is concluded that optimized results in this study could contribute in future research studies to select the parameters and methods to extract keratin films from recyclable wool fibers. Also, WK loaded nanofibrous films could be potential in filtration, air purification and tissue engineering.

Intrinsic curvature in wool fibres is determined by the relative length of orthocortical and paracortical cells

Hair curvature underpins structural diversity and function in mammalian coats, but what causes curl in keratin hair fibres? To obtain structural data to determine one aspect of this question, we used confocal microscopy to provide in situ measurements of the two cell types that make up the cortex of merino wool fibres, which was chosen as a well-characterised model system representative of narrow diameter hairs, such as underhairs. We measured orthocortical and paracortical cross-sectional areas, and cortical cell lengths, within individual fibre snippets of defined uniplanar curvature. This allowed a direct test of two long-standing theories of the mechanism of curvature in hairs. We found evidence contradicting the theory that curvature results from there being more cells on the side of the fibre closest to the outside, or convex edge, of curvature. In all cases, the orthocortical cells close to the outside of curvature were longer than paracortical cells close to the inside of the curvature, which supports the theory that curvature is underpinned by differences in cell type length. However, the latter theory also implies that, for all fibres, curvature should correlate with the proportions of orthocortical and paracortical cells, and we found no evidence for this. In merino wool, it appears that the absolute length of cells of each type and proportion of cells varies from fibre to fibre, and only the difference between the length of the two cell types is important. Implications for curvature in higher diameter hairs, such as guard hairs and those on the human scalp, are discussed.

Application of Scanning Electron Microscopy and Fourier-Transform Infrared Spectroscopy to Study Surface Design and Chemical Group Components of Merino Wool, Paschmina and Angora Fibers

Application of Scanning Electron Microscopy and Fourier-Transform Infrared Spectroscopy to Study Surface Design and Chemical Group Components of Merino Wool, Paschmina and Angora Fibers

Improving anti-felting characteristics of Merino wool fiber by 2.5 MHz atmosphere pressure air plasma

The present work investigates the effect of high frequency (2.5 MHz) Dielectric Barrier Discharge (DBD) in air on surface characteristics of Merino wool as a function of plasma exposure time (5s to 15s). The FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy Dispersive X-ray spectrum) and Derivative ATR-FTIR (Attenuated Total Reflection- Fourier Transform Infrared) Spectroscopy are used to study physio-chemical changes induced by plasma. These physio-chemical properties of fibers can be co-related with the felting behaviour of the wool fiber, which leads to shrinkage and pilling of garments while laundering. Felting occurs mainly because of presence of outermost hydrophobic cuticle layer having sharp scales. The FE-SEM analysis of wool fiber surface reveals that cuticle scales on wool fiber become blunt after plasma processing. The ATR-FTIR analysis along with second order derivative spectroscopy demonstrates the cleavage of di-sulphide bonds of cuticle and formation of sulphur-oxygen groups such as Cystine Sulphonate (-S-SO3-), cysteic acid (-SO3-), cystine monoxide(-SO-S-), cysteine di-oxide (-SO2-S-). A possible explanation about how the combined effect of morphological and chemical changes induced by plasma results in minimizing the felting of wool fibers is discussed.

Reconstituted Keratin Biomaterial with Enhanced Ductility

Nowadays the waste from protein fibres represents an important renewable source for a new generation of biomaterials and promising competitors for carbohydrate based biomaterials. Regenerated keratin biomaterials are biodegradable in vivo and in vitro, biocompatible, and support cell attachment and proliferation; however, their major drawback has been their weak mechanical properties such as ductility. The following study was conducted in an attempt to improve the ductility of reconstituted keratin films obtained from Australian merino wool fibres. Keratin was extracted from wool fibres according to an established protocol proposed by Yamauchi, and then dialyzed and desalted by multiple diafiltration wash cycles. The resulting keratin film was transparent, biodegradable, and, opposite to its predecessors, mechanically durable, possessing a Young modulus about 12.5 MPa with 35% extensibility. The polypeptide chains were found to rearrange themselves in the β-sheet state in this keratin film, which was shown to be semi-crystalline. This film, unlike its predecessors, did not support human cell proliferation. These properties of the diafiltered keratin film have led us to think that diafiltration resulted in producing a totally new keratin film, which is envisaged to find applications in various areas.

Extended Studies on Fibre Diameter Measurement with OFDA Instrument

OFDA 2000 is a widely used fibre diameter measurement instrument. The instrument can provide improved statistical accuracy measurements in comparison with traditional technology. In this paper, a new technique has been developed to enable fibre diameters to be measured in an aqueous environment using the OFDA 2000 instrument. This new technique was utilised to assess the effects of pH and temperature on the diameters of Merino wool fibres in aqueous environments. Significant changes in fibre diameter under aqueous conditions were found as a function of pH and temperature. It is also demonstrated in this paper that the fibre diameter measurement results can be affected by fibre colour. In both dry and aqueous conditions, variation in fibre diameter was observed on fibres with different colours. This could be due to an optical effect or more likely due to physical changes in the dyed fibres as a result of the presence of dyes. Apart from their physical bulk, dyes may also affect the water content of fibres and hence have an influence on the swelling of fibres when they are measured under ambient regain and wet conditions.

Keratins extracted from Merino wool and Brown Alpaca fibres: Thermal, mechanical and biological properties of PLLA based biocomposites

Keratins extracted from Merino wool (KM) and Brown Alpaca fibres (KA) by sulphitolysis and commercial hydrolyzed keratins (KH) were used as fillers in poly(l-lactic) acid based biocomposites processed by solvent casting in chloroform. Different contents (1 wt.% and 5 wt.%) of keratins were considered and the morphological, thermal, mechanical, chemical and biological behaviours of the developed PLLA biocomposites were investigated. The results confirmed that surface morphologies of biocomposites revealed specific round-like surface topography function of different microsized keratin particles in different weight contents, such as the analysis of bulk morphologies which confirmed a phase adhesion strictly dependent by the keratin source. Transparency and thermal responses were deeply affected by the presence of the different keratins and their interaction with the PLLA matrix. Tensile test results underlined the possibility to modulate the mechanical behaviour of PLLA selecting the keratin type and content in order to influence positively the elastic and/or plastic response. It was demonstrated that surface characteristics of PLLA/KA systems also influenced the bovine serum albumin adsorption, moreover PLLA and PLLA biocomposites based on different kinds of keratins supported the culture of human bone-marrow mesenchymal stem cells, indicating that these biocomposites could be useful materials for medical applications.

Keratins extracted from Merino wool and Brown Alpaca fibres as potential fillers for PLLA-based biocomposites

This paper reports on the promising per- spectives of using keratins extracted by sulphitolysis reaction from Merino wool (KM) and Brown Alpaca fibres (KA) in poly (L-lactide) (PLLA)-based biomateri- als. Both types of keratin were dispersed in chloroform (CHCl3) and tetrahydrofuran (THF), and optimisation of dispersion methods and parameters using the two selec- ted solvents was considered. The extraction yield, as well as supermolecular structures, morphology and ther- mal behaviour of the two proteins before and after the regeneration in CHCl3 was investigated. The results indicated that the supermolecular structures and thermal behaviour of the two proteins were affected by the interaction with CHCl3, producing decrease of the amount of a-helix structures in KM and an increase for KA, a slight decrease of b-sheet structures and a reduced thermal stability of a-crystallites for both keratins. Biocomposite films based on PLLA polymer matrix and two different contents of Merino wool and Brown Alpaca keratins (1 % and 5 % wt) were successfully developed by solvent casting in chloroform and the resulting morphologies after incorporation of different keratins (as a function of content and source) give evi- dence of different surface topographies, with a random distribution of keratin in flask-like structure. PLLA/5KA and PLLA/5KM samples with 1 % and 5 % wt of ker- atins show a specific pore-like surface microstructure, induced by solvent evaporation.

Instrumental evaluation of orthogonal tactile sensory dimensions for fine lightweight knitted fabrics

Lightweight fabrics knitted from fine and ultrafine merino wool fibres are emerging as a niche market for next-to-skin wear. The tactile sensory properties of these fabrics are investigated in this study. Seven pairs of bi-polar descriptors were defined from a survey as the most important tactile attributes for this target market. Furthermore, the existence of collinearity between the descriptive attributes was removed and three orthogonal tactile sensory dimensions were established by using principal component analysis. These three orthogonal tactile sensory dimensions explain 92.6% of the total variance of the seven tactile attributes. Partial least squares regression analyses showed that the Wool Handle Meter was capable of predicting the three tactile sensory dimensions.

Designing the strength properties of yarn using polyacrylonitrile fibers

A new technology of machine yarn for suit fabrics with a homespun surface and a soft knitted structure with Merino wool 64k tops and polyacrylonitrile fibers inserted into the mixture has been developed under the conditions of the textile firm “Kupavna.” Using analytical methods for designing yarn, theoretical calculations are performed of the strength of machine yarn developed from tops ribbon, Merino wool, and polyacrylonitrile fibers. The combing process is optimized; the optimal sizes of the feed and sorting zones are determined, thereby making it possible to reduce by 11.5% the content of fibers shorter than 50 mm.