Mohair Fibers Research Articles

The Application of Raman Spectroscopic Ratiometric Analysis for Distinguishing between Wool and Mohair

ABSTRACT Wool and mohair fiber bundles were analyzed using a Fourier transform (FT) Raman system, equipped with a Nd:YAG excitation laser (1064 nm), with the aim of determining whether such a system can be used to distinguish between the two fiber types in practice. Wool and mohair fibers were found to have virtually identical Raman spectra, except for the relative peak heights of certain chemical bands. Nevertheless, the individual values of the wool and mohair peak height ratios B (I1655/I1450), C (I1004/I1450), E (I936/I1450), F (I644/I1450) and G (I622/I1450) varied and overlapped considerably although the mean values of two of the most promising ratios; namely A (I2932/I1450) and D (I508/I1450) differed statistically significantly (p < .05) for wool and mohair, their individual values overlapped considerably, ranging from 2.71 to 3.68 for A and 0.18 to 0.32 for D, respectively, for wool and from 2.35 to 3.08 and 0.17 to 0.22, respectively, for mohair. This meant that the application of these ratios, to distinguish between wool and mohair, will be extremely difficult if not impossible. Nevertheless, tentative threshold values were identified, using the frequency distributions of the individual values, for both ratios A and D, which can be used to determine whether or not a sample is pure mohair. It is necessary, however, to analyze a much larger number of wool and mohair samples from various countries to validate the accuracy (reliability) of these threshold values. From the results of this study, it can be concluded that the application of Raman spectroscopic ratiometric analysis could have a potential application in detecting counterfeiting in pure mohair products.

Study on properties of yak cashmere fiber

PurposeAs one natural fiber, yak cashmere has been used more and more widely on textile processing due to its excellent warmth retention property. Yarn spinning is the first and the most important step of textile processing. Yarn spinning is closely related to the fiber properties. That is, for giving the optimization spinning process of one new fiber, the properties of the new fiber should be studied firstly. Meanwhile, during the studying of the properties of the new fiber, comparative analysis method was usually used. That is, the property of the new fiber was common comparatively analyzed with other fibers. During the comparative analysis, the spinning process can be optimized. Therefore, in the paper, the properties of the yak cashmere were studied in detail and comparatively analyzed.Design/methodology/approachThe brown yak cashmere, cyan yak cashmere, white cashmere fiber, purple cashmere fiber, cyan cashmere fiber, camel hair fiber and mohair fiber, were chosen as the samples. The fiber length, fineness, strength, curls, moisture regain, mass specific resistance, surface morphology, infrared spectrum, melting behavior, thermal weight loss, friction, x-ray, were tested and comparatively analyzed.FindingsIt is shown that the compositions of yak cashmere and cashmere are similar, and makes the physical properties of yak cashmere and cashmere fiber similar. Comparing with the mohair, camel hair and cashmere fiber, the average length of yak cashmere is smaller and the dispersion of length distribution is larger, and the dispersion of yak cashmere strength is larger, which makes the yarn spinning of yak cashmere difficult, especially the high count pure yarn. However, comparing with the mohair, camel hair and cashmere fiber, the friction coefficient and friction effect of yak cashmere is larger, and yak cashmere fiber has relatively less curls and larger crimp rate and crimp recovery rate, and can improve the fiber spinnability.Originality/valueIn the paper, taking the brown yak cashmere, cyan yak cashmere, white cashmere fiber, purple cashmere fiber, cyan cashmere fiber, camel hair fiber, mohair fibers as the samples, the properties of the yak cashmere were studied in detail. The fiber length, fineness, strength, curls, moisture regain, mass specific resistance, surface morphology, infrared spectrum, melting behavior, thermal weight loss, friction, x-ray, were tested and comparatively analyzed. The studies can establish foundation for the optimization of the yak cashmere spinning process, and also can provide information for the end uses of the fiber.

The Effect of Dyeing and Mohair/Wool Blend Ratio on Fabric Physical Properties

ABSTRACT In this study, dyeing effects on the physical properties of blended fabrics containing different ratios of wool and mohair fibers were investigated in detail. Six types of fabrics were produced by using 100% wool yarns and 100% mohair yarns separately in either direction with different sequences. Then the fabrics were dyed with a wool reactive dye and physical properties were investigated before and after dyeing process. As a result of the study, wool/mohair blended fabrics could be used in the lightweight suitings since adding mohair in the fabric composition made the fabrics stiffer, less drapeable, more air permeable. Another important finding was that the color yield values of both front and back sides of the 50/50% blended fabrics were found to be quite close. From this point of view, if wool and mohair yarns were used symmetrically in the fabric structure, it would be possible to dye blended fabric uniformly in one bath. Otherwise, in case of weaving fabrics according to various designs using wool and mohair yarns separately in either direction unsymmetrically, two different tones could be obtained on the same fabric, known as a bicolor effect.

Comparison of the Physical and Handle Properties of the Fabrics Produced from Wool and Mohair

ABSTRACT In this study, the differences of the fabric properties produced from wool and mohair fibers were investigated. By using 100% wool yarns and 100% mohair yarns separately in warp direction and the same yarns in the weft direction with different sequences, six types of fabrics were produced. The handle properties of the fabrics were tested with SiroFAST. Thickness of the fabrics made of mohair fibers was higher than that of the wool fabrics and the fabric thickness increased as the mohair proportion in the composition of the fabrics increased. Due to the higher volume of mohair yarns, bending rigidity both in the warp and weft directions of the fabrics produced with 100% mohair fibers was higher than that of the fabrics produced with 100% wool fibers. Elongation values of the wool fabrics both in the weft and the warp directions were higher than those of the fabrics produced with mohair yarns. The highest shear rigidity was obtained with the 100% wool fabric. The results of relaxation shrinkage and hygral expansion showed that there was no consistent relationship found between the results of the fabrics with regard to the fiber type.

Prickle and handle properties of fabrics produced from specialty animal fibers

Specialty animal fibers are commercially valuable since they significantly enhance the comfort properties of apparel products. As they help to create niche products, use of special animal fibers has increased significantly. There are many types of specialty fibers, such as cashmere, mohair, alpaca, and angora rabbit fibers, that are natural, ecological, and sustainable. Each of them has distinguishing properties and increases the added value of garments. In this work, five different specialty animal fibers and wool were sourced from four different countries. Yarns were spun using two different spinning systems. In the first method, to spin the yarns in a short staple spinning system, animal fibers were blended with viscose fibers. In the second method, to produce fabrics from 100% animal fibers, core yarn spinning system was used. Later, the yarns were knitted in a single jersey structure. After the production of all fabrics, handle properties such as surface friction, stiffness, and prickliness were tested by using both subjective and objective measurement techniques. To measure inherent fabric prickle, a new objective measurement technique was developed. Subjective and objective evaluation results highly correlate and it is pointed out that the new technique could be an alternative method to test fabric prickliness. Fabrics produced from silk, angora, and cashmere fibers are found to have the smoothest, softest, and least prickly surfaces among the other researched fibers.

Characterizing Visually Objectionable and Nonobjectionable Medullated Fibers in Mohair

The objectives of this research were to determine and define the characteristics of visually “objectionable medullated” (i.e., “kemp type”) fibers and “nonobjectionable medullated” fibers in mohair and to establish which characteristic(s) best distinguish between them, when examining whole fibers, as opposed to fiber snippets, the latter having been the case in earlier research. It was found that the mean medulla to diameter ratio (Med Ratio) distribution of individual visually objectionable medullated whole fibers overlapped significantly with that of visually nonobjectionable medullated fibers, confirming previous studies on fiber snippets, that Med Ratio on its own does not represent a reliable criterion for consistently and accurately distinguishing between visually objectionable and nonobjectionable medullated mohair fibers. Taking fiber and medulla diameter, type and length into consideration in addition to Med Ratio did not appear to substantially improve the ability to differentiate between the two types of fibers. This aspect, together with the cellular nature of the medulla, will be the focus of future research.

Interspecies Comparison of Morphology, Ultrastructure, and Proteome of Mammalian Keratin Fibers of Similar Diameter

Sheep wool has traditionally been viewed as the representative mammalian keratin fiber for the purposes of describing morphology and protein composition. We have investigated narrow fibers from the under-hairs of a range of species both closely and distantly related to sheep, comparing structure and protein composition. Within this group, curvature was negatively correlated with diameter for all but mohair. The cortical cell types present in alpaca, rabbit, and mohair fibers differed structurally from wool, primarily in terms of their macrofibril architecture. Except for rabbit, each species' fibers contained three cell types, and except for mohair, cell types were distributed asymmetrically across the cortex. In mohair, the cell types were distributed annularly, and each cell type had regions in which intermediate filaments were packed into highly aligned hexagonal mosaics, much like the mesocortex in wool. Coupled with this, were differences in the protein profiles; the rabbit fiber contained extra keratins and keratin associated proteins, while only subtle differences were noted between mohair and Merino fibers. In both rabbit and mohair fibers, the relative abundance of keratin K85 was lower than that of Merino. These results suggest that there may be links between relative protein composition and fiber morphology, albeit complex ones.

Atmospheric plasma advantages for mohair fibers in textile applications

In this study, mohair fibers were treated by air and argon plasma for modifying some properties of fibers. The fibers were evaluated in terms of their hydrophilicity, grease content, fiber to fiber friction, shrinkage, dyeing, and color fastness properties. The surface morphology was characterized by SEM images. The results showed that the atmospheric plasma has an etching effect and increases the functionality of a wool surface, which is evident from SEM and FTIR-ATR analysis. The hydrophilicity, dyeability, fiber friction coefficient, and shrinkage properties of mohair fibers were improved by atmospheric plasma treatment.

16- CIEPO'NUN ARDINDAN (International Committee of Pre-Ottoman and Ottoman Studies)

Tiftik, Ankara Keçisinin parlak yünüdür. En önemli özel hayvansal liflerden birisidir. Tiftik özellikle giysi ve ev tekstili olmak üzere geniş bir kullanım alanına sahiptir. Bu yazıda, tiftik liflerinin terbiye işlemleri üzerinde yapılmış önceki çalışmalar özetlenmektedir

Mechanical Profilometry of Wool and Mohair Fibers

In the scanning electron microscope, the surface of wool fibers is much rougher than that of mohair or other specialty fibers, mainly due to differences in the frequency and height of the cuticle scales. In order to assess and quantify these differences, which are essential for the perception of "roughness" and thus for fast fiber discrimination, mechan ical profilometry is used to assess coarse Merino wool and Texas mohair fibers. The data are analyzed by smoothing and Fourier analysis to separate cuticle-related effects of roughness from longer term fiber diameter changes attributed mainly to the characteristic circadian (daily) biological rhythm of the animal. The results show that subjectively observed differences in the roughness of the two fiber types are reflected in roughness and frequency parameters obtained from their mechanical profiles, enabling reliable discrim ination between wool and mohair.

The nutritional control of the growth and properties of mohair and wool fibers: a comparative review2

The effect of nutrient status on the growth and properties of wool and mohair fibers is reviewed: the aim is to compare effects on sheep and Angora goats and emphasize differences between the species. Wool growth is markedly influenced by nutrition; the requirement for energy-yielding nutrients is low and the major nutrients limiting wool growth are essential AA, sulfur-containing AA being especially important. An adequate supply of Cu, Zn, folic acid, and pyridoxine is required to maintain wool growth. Both length growth (L) and diameter (D) of wool fibers respond to changes in nutrient supply such that the ratio of L:D remains approximately constant. Mohair production is influenced by nutrient supply. However, the importance of specific nutrients has not been established, apart from one study showing that mohair growth responded to parenteral supplementation with methionine. In contrast to sheep, some studies indicate that length growth of mohair fibers may not be very responsive to changes in nutrient status. The responsiveness of mohair growth (both length and diameter) to nutrient supply at different times of the year has not been reported. The energy requirement for fiber growth may be greater in goats than in sheep, but more studies are needed.

Quantitative Fiber Mixture Analysis by Scanning Electron Microscopy

Results are reported of a round trial on the analysis of mohair/wool blends by scanning electron microscopy conducted under the auspices of the International Mohair Association. The identification of the fibers in a blend is based on the pronounced difference in the cuticle scale height at the distal edge for mohair and wool fibers which is readily detected in the scanning electron microscope. Twenty-one samples were analyzed by three laboratories. The results show good agreement between reference and analysis results and indicate that the major component of the analysis error is the random error inherent to the microscopical approach to fiber analysis.

Optical Anisotropy in Mohair Fibers

The diffraction from a He-Ne laser beam was used to measure the dimensional parameters, transverse sectional shape, and area of mohair fibers. Multiple-beam Fizeau fringes in transmission, and double refracting interference microscopy (Pluta polarizing interference microscope) were used to measure the refractive indices and birefringence of the mohair. The double-beam technique was applied to determine the mean re fractive indices for plane polarized light vibrating parallel and perpendicular to the fiber axis and thus the mean birefringence. Two other recent analytical methods were employed to study the optical properties of fibers from the interference patterns pro duced by the formation of multiple-beam Fizeau fringes crossing mohair fibers. These methods were used to determine Cauchy's constants and the thermal coefficient of refractive indices of the skin and core of the mohair. A comparative study of these methods is discussed and illustrated using photomicrographs.

Measuring Scale-Engagement of Wool and Mohair Fibers

Measuring Scale-Engagement of Wool and Mohair Fibers

Sensitive instrument to measure the friction between single fibers in various media

A sensitive instrument is described that measures the frictional and normal forces while nearly parallel fibers are rubbed in various media at normal forces down to 1 mg and rubbing speeds slow enough to ensure continuous contact. Typical frictional output traces are shown for human hair and coarse mohair fibers in water. The instrument detects scale engagement of keratin fibers.

OBSERVATION OF THE DEFORMATION PROCESS OF WOOL AND MOHAIR FIBERS BY SCANNING ELECTRON MICROSCOPY

A specimen deformation apparatus for scanning electron microscope was devised and the surface structures of merino wool and mohair fibers were observed from relax to break down under stretching and twisting.The specimens were prepared by coating gold on their surface. Electron microscopic observation of these specimens could be easily performed even in largely deformed state without charging.The scanning electron micrographs reveals that the scales of mohair are thin and flat, and are piled more closely one upon another compared with those of merino wool. The shape of break ends of these fibers stretched or twisted slowly is characteristic, and it relates to their fine structure composed of A (para-) and B (ortho-) cortices. Since both cortices separate from each other in their boundaries during deformation, merino wool gives break ends of bilateral type, while mohair gives that of sheath and core.

Preliminary Results on the Elastic Moduli of Wool, Mohair, and Kemp Fibers by Ultrasonic Pulse Techniques

The preliminary difficulties involved in exciting single animal fibers to act as elastic waveguides at 0.5 MHz have been overcome. Propagation constants of the lowest-order vibration modes were used to calculate the respective elastic constants of the fibers.

Set/Supercontraction Characteristics and Longitudinal Swelling of Keratin Fibers

The longitudinal swelling of three different sorts of wools, when permanently set, has been studied. It has been observed that, when progressively set, Mohair fibers, which acquire a set much more readily, show retarded swelling, compared to Blackface wool fibers. The effect of setting time reveals that the structure of Mohair fiber opens up at a much faster rate, but the swelling is high in the case of Blackface wool fiber which exhibits poor settability. Moreover, in each case, fibers, on acquiring a certain set, show a decrease in longitudinal swelling due to bond re-formation. It appears that the increase in longitudinal swelling, which is due to changes in the cortical regions, is influenced not only by the setting strain or the setting time; the number of strained bonds initially present and the ease of bond re-formation also determine the extent of swelling.

Comparison of Young's Modulus for Bending and Extension of Single Mohair and Kemp Fibers

The bending and extension moduli of single mohair and kemp fibers have been deter mined and compared. Previous results are not consistent—bending moduli values rang ing from larger-than to smaller-than the values obtained by stretching. Moduli for bending and stretching of mohair were found not to differ significantly, while kemp fibers can be divided into two distinct bending moduli groups, depending, ap parently, on the structure of the medulla. The medulla of these kemp fibers may be solid or hollow (semi-solid), yielding two different results for bending. Stretching moduli for all kemp fibers do not differ significantly and are comparable with the bend ing moduli of hollow fibers only.

A Comparison of the Tensile Properties of Kemp, Mohair, and Wool Fibers

A comparative study has been made of the breaking strength and extension-at-break of mohair, kemp, and wool fibers. The results point towards the presence of material in the medulla of kemp fibers, which does not contribute significantly towards the breaking strength of the fibers but which has a dielectric constant comparable to that of the rest of the fiber. Breaking strengths of kemp and mohair fibers are significantly higher than those of merino and German merino fibers.