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1.
Fiber irregularity affects fiber mechanical properties. This study has, for the first time, introduced the concept of limiting
irregularity to single wool fibers. The limiting irregularity is the minimum variation in fiber cross sectional area that
can be expected of a single wool fiber, assuming a random length-wise distribution of its constituent cortical cells. Cortical
cells were extracted from merino wool fibers and their dimensions were measured from SEM images to calculate their cross sectional
area variations both between cortical cells and within cortical cells, and to work out the average number of cortical cells
in the cross section of wool fibers of a given diameter. Single wool fibers were also measured at 5 μm interval along length
for fiber diameter variations. These variations were found to be larger than that based on fiber limiting irregularity. 相似文献
2.
The cross-section area of animal fibers varies along the fiber length, and this geometrical irregularity has a major impact
on the mechanical properties of those fibers. In practice fibers are often subjected to tensile stresses during processing
and application, which may change fiber cross-section area. It is thus necessary to examine geometrical irregularity of fibers
under tension. In this study, scoured animal fibers were subjected to different tensile loading using a Single Fiber Analyzer
(SIFAN) instrument. The 3D images of the fiber specimens were first constructed, and then along-fiber diameter irregularities
of the specimens were analyzed for different levels of tensile loading. The changes in effective fineness of the fiber specimens
were also discussed. The results indicate that for the wool fibers examined, there is considerable discrepancy in the fiber
diameter results obtained from the commonly used single scan along fiber length and that from multiple scans at different
rotational angles, and that the diameter variation along fiber length increases as fiber tension increases. The results also
show that when diameter reduction treatments are applied to wool by stretching, the reduced average fiber diameter is associated
with an increase in both within-fiber and between-fiber diameter variations. So in terms of effective fineness, the change
is much smaller than the difference between the average diameters of the parent and treated wool. These results have significant
implications for improving the accuracy of fiber diameter measurement and evaluation. 相似文献
3.
In this study, corona discharge treatment was applied to modify the surface of cotton fibers at various temperatures. The fiber surface was roughened during this treatment and the surface oxygen content increased at a considerably low temperature, and then declined when temperature increased. Weight loss rate showed the treatment was fiercer as treated temperature increased. The breaking strength and surface adhesion property of the fabric treated with starch sizing increased to a certain extent and then decreased. These results suggest that the treated temperature plays a great role in the surface properties of cotton fiber when treated via corona discharge. 相似文献
4.
5.
The maximum strain experienced by the thinnest segment of a non-uniform fiber governs fiber breakage, yet this maximum strain
can not be obtained from a normal single fiber test. Only the average strain of the whole fiber specimen can be obtained from
a normal single fiber tensile test. This study has examined the relationship between the average strain, the maximum strain
and the degree of fiber non-uniformity, expressed in coefficient of variation (CV) of fiber diameters along fiber length.
The tensile strain of irregular fibers has been simulated using the finite element method (FEM). Using this method, average
and maximum tensile strains of non-uniform fibers were calculated. The results indicate that for irregular fibers such as
wool, there is an exponential relationship (i.e.ɛ
ave
ɛ
max=ae
−b CV
) between the ratio of average breaking strain and maximum breaking strain (ɛ
ave
ɛ
max) and the along-fiber diameter variation (CV). The strain ratio decreases with the increase of the along-fiber diameter variation. 相似文献
6.
In order to investigate psychoacoustic characteristics of fibers, and to compare them with sound physical parameters, each
sound of 25 different fabrics consisted of a single fiber such as wool, cotton, silk, polyester, and nylon was recorded. Sounds
of specimens were transformed into critical band diagram and psychoacoustic characteristics including loudness and sharpness
for each sound were calculated based on Zwicker’s models. Physical parameters such as the level pressure of total sound (LPT),
level ranges (ΔL), frequency differences (Δf), AR coefficients (ARC, ARF, ARE) were obtained in fast fourier transform (FFT) spectrum. Nylon taffeta showed higher values
for loudness than 2.5 sone corresponding to human low conversation, while most silk fibers generated less louder showing lower
values for loudness than 1.0 sone. Wool fibers had higher loudness mean value than that of cotton, while the two fibers didn’t
differ in LPT. Loudness showed high positive correlation coefficients with both LPT and ARC. Sharpness values were higher
for wool fiber group than other fibers. Sharpness was not concerned with loudness, LPT, and ARC, but the fabrics with higher
values for sharpness tended to show higherΔL. 相似文献
7.
A water and dye-free heat treatment method was used to color wool fibers. The heat effect changed wool fibers to different colors from white in a nitrogen atmosphere. The influences of heating temperature and time on the colors of wool were investigated and the mechanical property of colored wool fibers was evaluated. The color strength of wool fibers increased as heat treatment temperature and time increased. The tensile strength retention rate of wool fiber was relatively high (≥90 %) when the heat temperature was below 200 °C. The surface morphologies of wool fibers scarcely changed during the heat treatment. The carbon content of fibers was found to reduce by heat treatment, indicating oxidization of components in the wool fibers in the process of coloration. Heat treatment may provide a water and dye-free approach to color wool and other textile fibers, albeit within a limited color range. 相似文献
8.
Most fibers are irregular, and they are often subjected to combined loading conditions during processing and end-use. In this
paper, polyester and wool fibers under the combined tensile and torsional loads have been studied for the first time, using
the finite element method (FEM). The dimensional irregularities of these fibers are simulated with sine waves of different
magnitude and frequency. The breaking load and breaking extension of the fibers at different twist or torsion levels are then
calculated from the finite element model. The results indicate that twist and level of fiber irregularity have a major impact
on the mechanical properties of the fiber and the effect of the frequency of irregularity is relatively small. 相似文献
9.
C. W. Kan 《Fibers and Polymers》2006,7(3):262-269
In this paper, the effects of low temperature plasma (LTP) treatment on the dyeing properties of the wool fiber were studied.
The wool fibers were treated with oxygen plasma and three types of dye that commonly used for wool dyeing, namely: (i) acid
dye, (ii) chrome dye and (iii) reactive dye, were used in the dyeing process. For acid dyeing, the dyeing rate of the LTP-treated
wool fiber was greatly increased but the final dyeing exhaustion equilibrium did not show any significant change. For chrome
dyeing, the dyeing rate of the LTP-treated wool fiber was also increased but the final dyeing exhaustion equilibrium was only
increased to a small extent. In addition, the rate of afterchroming process was similar to the chrome dyeing process. For
the reactive dyeing, the dyeing rate of the LTP-treated wool fiber was greatly increased and also the final dyeing exhaustion
equilibrium was increased significantly. As a result, it could conclude that the LTP treatment could improve the dyeing behavior
of wool fiber in different dyeing systems. 相似文献
10.
The HVI properties and Mantis® single fiber tensile properties were analyzed to evaluate the relationship between fiber and bundle tensile properties. For this study, a new method has been developed for estimating the modulus and toughness of cotton fiber bundles directly from the HVI tenacity-elongation curves. The single fiber tensile properties were shown to be translated well into the bundle tensile properties. The single fiber breaking elongation was found to be the most significant contributing factor to bundle tensile properties. The bundle breaking elongation and toughness were shown to increase as the single fiber breaking elongation increased. The bundle modulus increased as the single fiber breaking elongation and/or standard deviation of single fiber breaking elongation decreased. 相似文献
11.
Near infrared spectroscopy coupled with chemiometric analysis was investigated as a fast and non destructive method for the identification of wool, cashmere, yak, and angora rabbit fibers in the raw and combed sliver state and for the quantitative determination of cashmere in cashmere/wool blends. The main differences among spectra of different animal hair arise from physical charateristics rather than chemical characteristics (mainly pigmentation and mean diameter) of animal fibers. The Soft Independent Modelling by Class Analogy method allows the classification of distinct fibers into separate groups with interclass distances ranging from 12.64 for the nearest classes (white cashmere and wool) to above 1000 for the most distant classes of white and pigmented fibers. Percentages of recognition and rejection of 100 % were found with the exception of a yak sample that was not rejected from the pigmented cashmere class (98 % of rejection). The prediction capacity of the model was also evaluated. Quantitative analysis was carried out using samples obtained by carefully mixing known amounts of wool and white cashmere. A standard error of the estimate of 8.5, a standard error of prediction of 13.10 and a coefficient of determination of 0.95 were calculated. From the results obtained, it can be concluded that near infrared spectroscopy can be used as a tool for an initial and rapid screening of unknown animal fiber samples in the raw and combed sliver states and for a fast and coarse estimate of the amount of cashmere in wool/cashmere blends. 相似文献
12.
Dispersion and separation of fiber bundles into individual fibers, requires exposing them to a shear stress field to overcome
inter-fiber frictional forces. To this end, fiber-mixing tanks are usually used to enhance shear and agitation in water and
help the dispersion process. The required time and necessary agitation to separate and disperse fibers depend on fibers’ characteristics.
It is well known that excessive agitation will give rise to the formation of rope defects in the output because of the high-energy
vortices and optimizing the break up time is important in wet-lay process. In this work, experimental and numerical studies
were done to investigate the effects of fiber characteristics on their dispersion in water for wet-laid nonwoven. The effective
forces were analyzed using a one-way modeling of fiber behaviors in a stirred mixing tank. Results show that when the fiber
diameter is increased, the required time for breaking up of fiber bundles and clumps is increased. The effects of fiber types
on fibers break up and dispersing time, were also investigated. In the experimental work, an on-line vision system was designed
to observe the dispersion behavior of polyester fibers. The effects of fiber length and fineness on the created defects (i.e.
logs and ropes) in dispersion process, as well as on the dispersion speed, were studied. The results confirm that defects
are increased by rising fiber length and fineness. It is also shown that increasing fiber length and fineness, decreases the
required time for fiber clumps to be opened and reach a maximum number of individual fibers. On the other hand, when fiber
length and fineness is increased, the dispersion speed increases. 相似文献
13.
Previous investigation results revealed that after the Low Temperature Plasma (LTP) treatment, the hydrophilicity of wool
fiber was improved significantly. Such improvement enhances the wool dyeing and finishing processes which might be due to
the changes of the wool surface to a more reactive one. In this paper, wool fibers were treated with LTP with different gases,
namely, oxygen, nitrogen and gas mixture (25 % hydrogen/75 % nitrogen). Investigations showed that chemical composition of
wool fiber surface varied differently with the different plasma gas used. The surface chemical composition of the different
LTP-treated wool fibers was evaluated with different characterization methods, namely FTIR-ATR, XPS and saturated adsorption
value. The experimental results were thoroughly discussed. 相似文献
14.
Lei Zhang Leng Han Yujun Wang Tianfu Zhao Xianxun Bao Masao Nakagaki 《Fibers and Polymers》2013,14(7):1190-1195
Spider dragline fiber is a high-performance biomaterial that has received much attention. To screen the outstanding spider dragline fibers, the mechanical properties and microstructures of dragline fibers collected from Nephia clavata, Nephia pilipes, Argiope bruennichi and Argiope amoena were investigated. It was found that the mechanical properties of spider dragline fiber were variable. Among the four different species, the larger spiders did not always extrude thicker dragline fibers and produce fibers with the maximum breaking force. The dragline fibers could sustain one to three times the body weight of the spider at a reeling speed of 20 mm/s. N. clavata dragline fiber showed a stronger breaking stress and initial modulus than that of N. pilipes, A. bruennichi and A. amoena. With an increasing reeling speed, the breaking strain decreased; the initial modulus increased in N. clavata, N. pilipes and A. bruennichi, but the breaking stress exhibited a different tendency. The results also revealed that dragline fiber of N. clavata contained the most β-sheet polypeptides and an excellent orientation of β-sheet molecular chains. 相似文献
15.
In this study, a natural dye extraction was carried out to isolate dyestuff extract powder from the waste barks of Turkish red pine (Pinus brutia Ten.) timber which is not a common natural dyestuff source. The natural dyestuff powder obtained was applied to cotton, flax, wool, silk, tencel, polyamide and acrylic fibers accompanied by simultaneous application of alum and natural oak ash mordants. Color properties were investigated including rub-, light- and wash-fastness performance. Differently dyed fiber samples exhibited slightly different shades of beige, brown and brownish-yellow depending on the mordant used and fiber type. Alum mordanted samples exhibited better color properties. The highest (63.4) and the second highest (45.3) f(k) color yield values were observed for alum mordanted silk and wool samples, respectively. Dyed fabrics showed excellent wash fastness, very low staining performance, and moderate light- and rub-fastness. 相似文献
16.
Youngwoong Kang Yongjun Ahn Sang Hyun Lee Joo Hyung Hong Min Kyung Ku Hyungsup Kim 《Fibers and Polymers》2013,14(4):530-536
Nano-size fibers from lignocellulosic biomass were successfully obtained by akali-treatment and electrospinning using ionic liquid. The effects of the lignin and the hemicelluloses content on the spinnability, the web morphology, the micro-structure and the thermal stability of the electrospun fibers were investigated. The lower lignin content resulted in better spinnability, fine and uniform fiber diameter, higher crystallinity and decrease of thermal stability. This study reveals the possibility of the utilization for the lignocellulosic biomass other than pulp or cotton. 相似文献
17.
In this study, normal and dichlorodicyanuric acid (DCCA)-treated wool slivers were ultrasonicated in formic acid aqueous solutions. The effect of the ultrasonication condition on the wool fiber splitting was examined and the mechanism of the splitting by ultrasonication in formic acid was elucidated. No wool fiber splitting occurred at formic acid content up to 70 %, but the fiber splitting accelerated as the formic acid content increased from 75 %. Although no fiber splitting occurred up to 450W ultrasonic power, the degree of splitting increased significantly with increasing ultrasonic power above 450W. The wool fiber splitting by ultrasonication was heterogeneous and FE-SEM observations revealed a three-step splitting process: 1) full removal of scale, 2) removal of cell membrane complex (CMC), and 3) fiber splitting. A comparison of the fiber splitting of normal and DCCA-treated wool revealed that the scale of the ultrasonication-treated wool was removed by peeling off rather than by dissolution. 相似文献
18.
An amino-terminated hyperbranched polymer (HBP-NH2), synthesized from methyl acrylate and diethylene tri-amine by polycondensation, was applied to treat cotton samples by a
pad-dry-cure method. Physical properties, salt-free dye-ability, antimicrobial activity, and antiultraviolet property of the
treated cotton samples were tested. The crystallinity and mechanical properties, including breaking strength, breaking elongation,
and Young’s modulus of the treated cotton fibers, increased slightly in comparison with those of the untreated cotton fibers.
The thermal stability and the moisture regain were also improved slightly. Dyed with direct dyes and reactive dyes in the
absence of the electrolytes, the treated cotton fabric showed similar or higher color strength compared with the untreated
cotton fabric in conventional dyeing. The treated cotton fabric can also be dyed with acid dyes effectively. In addition,
the treated cotton fabric showed good antimicrobial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The study of the antiultraviolet properties of the treated cotton fabric indicated that the HBP-NH2 contributed to the reduction of UV transmission and the increase of UPF. 相似文献
19.
Fiber quality is very important for all the steps of the textile area. Underwater shock wave has been utilized for metal,
wood, food processing and medical applications and renewed and increased application during the last decade. The main object
of this study, is to demonostrate underwater shock wave as a surface treatment of natural fibers such as jute and cotton in
form of yarn and to report characterized properties of the treated fibers. The underwater shock wave was generated by the
explosion of the detonation fuse in the water tank. The process of bubble generation and expansion inside the water results
in the formation of shock wave. Natural fibers were exposed to shock wave treatment depending on the different pressures and
detonatinon fuse separation distance. After shock-loading, fibers were selected for physicomechanical and physicochemical
tests such as Scaning Elecron Microscopy (SEM) analysis, breaking strength, moisture behavior, permeability and wicking test.
The maximum effect with improved moisture content, permeabilty and wicking properties were observed from 100 MPa. The treated
fiber showed high performance necessary for use in woven and non woven purpose. 相似文献
20.
对苎麻长麻纺（复精梳）工艺中的苎麻预并条和头道精梳条进行牵切,然后分别将其在棉纺设备上进行并条、粗纱和细纱加工。探讨牵切纱断裂强度与捻系数的相互关系,并对比分析牵切纱与常规纱的质量。结果表明,牵切纱临界捻系数αt 在405左右,苎麻牵切精梳纱的条干、粗细节、棉结及3 mm以上的毛羽与苎麻常规精梳纱的接近,且断裂强度优于苎麻常规精梳纱的。 相似文献