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1.
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
2.
Wool and alpaca fibers were coated with polypyrrole by vapor-phase polymerisation method. The changes in frictional and tensile
properties of the single fibers upon coating with the conductive polymer are presented. Coating a thin layer of polypyrrole
on the alpaca and wool fibers results in a significant reduction in the fiber coefficient of friction, as the conducting polymer
layer smooths the protruding edges of the fiber scales. It also reduces the directional friction effect of the fibers. Depending
on the type of fiber, the coating may slightly enhance the tensile properties of the coated fibers. 相似文献
3.
Alpaca fibers have some distinct properties such as softness and warmth, which have not been fully understood in combination
with the fiber internal structures. In the present investigation, the internal structures of alpaca fibers have been closely
examined under the scanning electron microscope (SEM), especially in the longitudinal direction. The results showed that numerous
pigment granules reside loosely inside pockets in brown and dark-brown alpaca fibers. These pigment granules were mainly distributed
inside the cortical cells, the medullation regions as well as underneath the cuticles. Their size in the brown alpaca fibers
was smaller and more uniformly round than in the dark-brown fibers. These granules in colored alpaca fibers loosen the bundle
of cortical cells, providing many crannies in the fibers which may contribute to the superior flexibility, warmth and softness
of the fibers. Moreover, there are no heavy metal elements found in the granules. The mordant hydrogen peroxide bleaching
employed could eliminate the pigment granules and create many nano-volumes for further dyeing of fibers into more attractive
colors. 相似文献
4.
In this study, a new type of Aliquat 336/PVC membrane has been made for extraction experiments. This new membrane is capable
of holding more Aliquat 336 than previously developed extraction membranes, hence overcoming a major problem that has confronted
many researchers for a long time. The new membrane has been used to investigate the rate of extraction for the Cd(II) ion
in 2.0 M HCl solution and the effect of membrane thickness on the rate of extraction. The experimental results have shown
this new membrane has a promising future in relevant industrial applications. A new method is also used in this study to qualitatively
identify the oily substance on the surface of membrane after the extraction experiment was completed. This oily substance
has been found to be Aliquat 336. 相似文献
5.
Previously, we have reported a method for producing photochromic wool fabric by applying a thin layer of hybrid silica-photochromic
dye onto the wool surface. While the photochromic coating showed a very fast optical response and had little influence on
the fabric handle, its durability was poor. In this study, the durability of the photochromic coating layer was improved by
introducing epoxy groups into the silica matrix via co-hydrolysis and co-condensation of an alkyl trialkoxysilane compound
(ATAS) and 3-glycidoxypropyltrimethoxysilane (GPTMS). The presence of epoxy groups in the silica enhanced both washing and
abrasion durability or fastness. In addition, the optical response speed was slightly increased as well. Effects of the type
of alkyl silane and the GPTMS/alkyl silane ratio on the coating durability, fabric handle and optical response were examined. 相似文献
6.
The ring spinning process has been used to produce fine and high quality staple fibre yarns. The stability of the rotating
yarn loop (i.e. balloon) between the yarn-guide and the traveller-ring is crucial to the success and economics of this process.
Balloon control rings are used to contain the yarn-loop, by reducing the yarn tension and decreasing the balloon flutter instability.
Flutter instability here refers to the uncontrolled changes in a ballooning yarn under dynamic forces, including the air drag.
Due to the significant variation in the length and radius of the balloon during the bobbin filling process, the optimal location
for the balloon control ring is not easily determined. In order to address this difficulty, this study investigates the variation
in the radius of a free balloon and examines the effect of balloon control rings of various diameters at different locations
on yarn tension and balloon flutter stability. The results indicate that the maximum radius of a free balloon and its corresponding
position depend not only on the yarn-length to balloon-height ratio, but also on yarn type and count. A control ring of suitable
radius and position can significantly reduce yarn tension and decrease flutter instability of free single-loop balloons. While
the balloon control rings are usually fixed to, and move in sinc with, the ring frame, results reported in this study suggest
that theoretically, a balloon control ring that always remains approximately half way between the yarn-guide and the ring
rail during spinning can lead to significant reduction in yarn tension. 相似文献
7.
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
8.
The standard tests for relaxation shrinkage and hygral expansion of wool fabric take no account of pH. It is shown in this
work that the pH of the solution in which wool fabric is relaxed as part of the procedure for measuring dimensional properties
has a significant influence on the results. At around pH 4.8, which is close to the isoelectric point of wool, the hygral
expansion reaches its greatest value and drops at both lower and higher pHs. A similar relationship between pH and extensibility
of wool fabric was observed. Values of relaxation shrinkage were found to be dependant on pH. The reasons for the pH dependence
of dimensional properties are discussed and these include changes in wool fiber swelling, yarn crimp and polymer relaxation
phenomena with changes in pH. 相似文献
9.
The compressive and flexural properties of hemp fiber reinforced concretes (FRC) were examined in this paper. Natural hemp
fiber was mixed using dry and wet mixing methods to fabricate the FRC. Mechanical properties of the FRC were investigated.
The main factors affecting compressive and flexural properties of the FRC materials were evaluated with an orthogonal test
design. Fiber content by weight has the largest effect. The method for casting hemp FRC has been optimised. Under the optimum
conditions, compressive strength increased by 4 %, flexural strength increased by 9 %, flexural toughness increased by 144
%, and flexural toughness index increased by 214 %. 相似文献
10.
This work presents a series of experimental tests on new practical approaches in membrane design to improve extraction capacity
and rate. We chose an extraction system involving Aliquat 336 as the extractant and Cd(II) as the metal ion to be extracted
to demonstrate these new approaches. The core element in the new membrane assembly was the extractant loaded sintered glass
filter. This membrane assembly provided a large interface area between the extractant and the aqueous solution containing
metal ions. By recycling the aqueous solution through the membrane assembly, the extraction rate was significantly improved.
The membrane assembly also offered good extraction capacity. 相似文献