共查询到20条相似文献,搜索用时 31 毫秒
1.
The present paper reports the detailed study on the splicing behavior of viscose staple fiber yarns made from ring, rotor,
friction and air-jet spinning technologies. The linear density of all the yearns was kept constant at 29.5 tex. The splicing
parameters like splicing pressure and duration of the splicing were taken as variables. Three levels of splicing pressure
at constant splicing duration and three levels of splicing durations at constant splicing pressure were considered. Splices
were introduced at all these levels for the four different technologies. These splices were tested for their tensile properties
and the properties of splices were evaluated in terms of retained splice strength (RSS) and splice break ratio (SBR). The
splice photographs were taken and splices were analyzed for their structure and for diameter profile along the length of the
splice. 相似文献
2.
The present paper deals with a detailed study on the effect of progressive yarn extension on diameter, overall packing fraction, radial packing fraction at different radial positions and partial packing fraction at different segments along the length of a fibre. An image processing based system to characterize and visualize the configuration of fibers in yarn in extended mode has been adopted. It has been observed that with the increase of yarn extension at different intervals, yarn diameter continuously decreases but at different yarn extension intervals, the percentage decrease value in the yarn diameter is different. But the packing density of yarn does not follow the exact trend of yarn diameter with the extension of yarn at different intervals. The yarn packing density initially increases at very high rate, then at very low rate and finally the packing density of yarn rather slightly decreases with the increase in yarn extension. The radial packing density of the yarn is not uniform across the cross-section of the yarn and it is not maximum near the yarn axis, rather it is maximum at some distance from the yarn axis. The location of maximum radial packing densities of yarn changes with the yarn extension. The partial packing density along the length of yarn is not uniform and the results are equally applicable for all level of yarn extension. 相似文献
3.
Coconut fibres were subjected to chemical treatment to obtain softer and finer fibres, suitable to blend with other finer fibre like jute. The chemical softening recipe was optimized using Box-Behnken design of experiments as 40 % Na2S, 10 % NaOH and 6 % Na2CO3, which notably reduced the fineness (33 %) and flexural rigidity (74 %) and improved tensile property of coconut fibre. Effect of softening of coconut fibre on its process performance was studied in high speed mechanized spinning system at different blend ratios with jute. Blending with jute assists in spinning of coconut fibre to produce yarn of 520 tex at production rate of 5-6 kg/h, as compared to 15 kg/day for hand spun 5300 tex raw coconut fibre yarn in manual system. Analysis of blended yarn structure in terms of packing density, radial distribution of fiber components (SEM) and mass irregularity were investigated. SEM shows yarns made from softened coconut fibre -jute blends are more compact than raw coconut fibre -jute blend yarns. Coconut fibres were preferentially migrated to core of the yarn. Major yarn properties viz., tensile strength, and flexural rigidity of raw and chemically softened blended yarns were compared against their finest possible 100 % coconut fibre yarn properties. Yarn made up to 50:50 chemically softened coconut fibre-jute blend showed much better spinning performance, and having superior property in terms of reduced diameter, higher compactness, strength, initial modulus and less flexural rigidity than 100 % raw, 100 % chemically softened coconut fibre rope, and raw coconut fibre-jute blend yarns. 相似文献
4.
The effect of blend percentage on comfort and handle related properties of fabrics made from polyester/viscose blended air-jet
textured yarn weft were studied and the results were compared with fabrics made from polyester/viscose ring-spun yarn wefts
of similar linear densities. It is observed that with increase in polyester content in the blend, the air permeability and
water vapour permeability reduces whereas thermal resistance, transverse wicking and shear rigidity increases both in ring-spun
yarn and textured yarn fabrics and bending rigidity increases in textured yarn fabrics. Textured yarn fabrics exhibit lower
air permeability and extensibility, higher thermal resistance, relative water vapour permeability, transverse wicking values
and bending rigidity as compared to the ring-spun yarn fabrics. 相似文献
5.
Fibres being the structural unit of a yarn, its nature, composition and arrangement can influence structure and properties. The performance of yarn changes with arrangement of its constituent fibres. Arrangement of fibres in a yarn being system specific, different spinning system results different arrangement of fibres causing variation in product performance. A change in the arrangement of fibres in an already formed yarn can be brought about by suitable physical and/or chemical treatment. A treatment to remove a component is expected to cause changes in final arrangement of fibres in a yarn. In the present study, polyester/PVA blended yarn was modified through dissolution of the later component. The resultant change in structural arrangement on dissolution was assessed by the change in radial packing distribution of fibres. Migration index, helped in identifying the location that was influenced more in the redistribution. In the parent yarn, PVA had a preferential tendency to predominate near the core. On dissolution of PVA, creation of open space was expected and collapsing of the structure led to a possible rearrangement of fibres and reduction in diameter of yarn. Fibre denier, blend ratio and twist factor were also found to influence packing density both in parent and modified yarn. Unlike published reports, interestingly, an increase in fibre packing density was observed on dissolution of PVA. Average packing density in parent yarn was found to lie at a yarn radius between 0.07 mm to 0.09 mm while for the modified yarn it was between 0.05 mm to 0.07 mm. 相似文献
6.
In the present study, an attempt has been made to obtain the relationships for prediction of yarn diameter from different fibers and spinning technologies. The Peirce formula is found to give high deviation from the observed values of yarn diameter because it does not take the effect of twist, type of fibre and spinning technology into consideration. A new empirical model has been proposed that takes into account the parameters affecting the yarn diameter to a great extent, namely yarn twist, spinning technology and type of fibre in calculating the yarn diameter. The spinning technology, type of fibre and the proportion of fibre in the yarn have significant effect on yarn diameter. The proposed model is able to predict the yarn diameter more accurately. 相似文献
7.
The moisture transport expressed with wicking is one of the most important aspects in clothing science and strongly effects on the quality of clothes. Wicking is a spontaneous transport of liquid driven into a porous system by capillary forces. Furthermore, the packing density has a direct relation with the yarn structure. At the present work, the effects of yarn count and twist factor on the wicking height and packing density of lyocell ring-spun yarns was investigated. Achieving the objectives of this research, an image processing method was developed to determine the packing density of samples. Experimental results were also used to develop a regression model to predict the wicking height based on the packing density, yarn count, twist factor and rising time. The results demonstrated that the correlation coefficient between the predicted and measured wicking height was 0.98 indicating the capability of the presented model to predict the wicking height of lyocell ring-spun yarns. 相似文献
8.
The present paper is concerned with the influence of opening roller speed, drum speed difference and suction air pressure
on properties of polyester and acrylic open-end friction spun yarns. The results shows that the opening roller speed and the
suction air pressure have considerable influence on the characteristics of polyester and acrylic open-end friction spun yarns.
In case of polyester yarns the unevenness, imperfection and hairiness decreases and the yarn tenacity increases with the increase
in opening roller speed and suction air pressure. However for acrylic yarns the unevenness and imperfections decreases and
tenacity increases with the increase in opening roller speed and suction air pressure. 相似文献
9.
The compact spinning with suction groove can eliminate or decrease the spinning triangle by airflow compacting and shape condensing of the groove, so the yarn hairiness can be reduced effectively for long staple fiber. But the resistance torques produced by the spinning tension and the negative pressure of airflow influence the twist propagation. This paper analyzes variation of the friction coefficient between the fiber bundles and the groove. The transfer process of the moment of the spinning tension and airflow is studied in the variation of the friction coefficient. The expression of the resistance torque is established in the gathering area. The results show that the many factors influence the resistance torque, such as the horizontal friction coeffecient between the fiber bundles and the groove, the spinning tension and the negative pressure, as well as the angle between two suction holes etc. The proper negative pressure and the spinning tension can prevent twist propagation, and can reduce the yarn hairiness and improve the yarn quality. 相似文献
10.
F. Hajiani A. A. Ghareaghaji Ali. A. A. Jeddi S. H. Amirshahi F. Mazaheri 《Fibers and Polymers》2014,15(9):1966-1976
In view of the interest in wicking properties of these flexible structures, analysis of the wicking phenomena in nylon 6.6 nanofiber yarns is carried out by considering the twist rate effects. A novel method is used based on adding a pH-sensitive dye to yarn interstructure and the analysis of color alteration of nanofiber yarn structure, resulting from a shift in pH, during the capillary rise of distilled water. The results show that the addition of pH- sensitive dye has no influence on the average nanofiber diameter and the wicking behavior of yarns. This study shows that in short durations, the kinetic of the capillary rise follows the Lucas-Washburn equation. The Lambertw, a mathematical function, has been incorporated, which helps measure an equivalent structural factor of nanofiber yarns and vertical wicking height at any given time considering the gravitational effects. The statistical results show that the average of equilibrium wicking height and capillary rise rate coefficient tend to decrease with increasing the nanofiber yarn twist, due to the reduction of continuity and size of capillaries. 相似文献
11.
Structural analysis of finer cotton yarns produced by conventional and modified ring spinning system
Yarn structure plays an important role in determining the properties of spun yarns. Recently, a modified spinning technique has been developed for producing a low torque and soft handle singles yarn by modifying the fiber arrangement in a yarn. Comparative studies revealed that the finer modified yarns possess significantly higher strength and lower hairiness over the conventional yarns of the same twist level, implying a different structure of finer modified yarn. Thus this paper aims to quantitatively study the structures of the finer conventional and modified cotton yarn (80 Ne) produced at the same twist level. Various measuring techniques, namely the Scanning Electron Microscope (SEM), cross section technique and tracer fiber technique, are adopted to analyze their structural characteristics, including fiber configuration, fiber spatial orientation angle, fiber packing density, yarn surface appearance, and fiber migration behavior. Results showed that finer modified yarns exhibit a smoother surface and much more compact structure with less hairiness. The fibers in the finer modified yarn have a complicated fiber path with relatively lower fiber radial position, larger migration frequency and magnitudes. In addition, it was noted that 73% of fibers in the finer conventional yarn follow concentric conical helix, which is contrary to those in the coarser conventional yarn. The analyses conducted in this paper provide deep insights into the mechanism of modified spinning technique and evidential explanations on the difference of properties between the finer conventional and modified yarns. 相似文献
12.
Yuman Zhou Hongbo Wang Jianxin He Kun Qi Bin Ding Shizhong Cui 《Fibers and Polymers》2018,19(10):2169-2177
Electrospinning is a simple and cost-effective method to prepare fiber with nanometer scale. More importantly, 3D flexible nanofiber yarns that fabricated by electrospinning have shown excellent application prospects in smart textiles, wearable sensors, energy storage devices, tissue engineering, and so on. However, current methods for preparing electrospinning nanofiber yarns had some limitations, including low yarn yield and poor yarn structure. In this paper, a stepped airflow-assisted electrospinning method was designed to prepare continuously twisted nanofiber yarn through introducing stepped airflow into traditional electrospinning system. The stepped airflow could not only help to improve nanofiber yield, but also good for controlling the formed nanofibers to be deposited in a small area. In addition, the experimental methods of single factor variables were used to study the effects of stepped airflow pressure, applied voltage, spinning distance, solution flow rate, air pumping volume and friction roller speed on nanofiber yarn yield, nanofiber diameter, yarn twist and mechanical property. The results showed that prepared nanofiber yarns exhibited perfect morphologies and the yield of nanofiber yarn could reach to a maximum of 4.207 g/h. The breaking strength and elongation at break of the prepared yarn could reach to 23.52 MPa and 30.61 %, respectively. 相似文献
13.
In this study artificial neural network (ANN) models have been designed to predict the ring cotton yarn properties from the
fiber properties measured on HVI (high volume instrument) system and the performance of ANN models have been compared with
our previous statistical models based on regression analysis. Yarn count, twist and roving properties were selected as input
variables as they give significant influence on yarn properties. In experimental part, a total of 180 cotton ring spun yarns
were produced using 15 different blends. The four yarn counts and three twist multipliers were chosen within the range of
Ne 20–35 and α
e 3.8–4.6 respectively. After measuring yarn tenacity and breaking elongation, evaluations of data were performed by using
ANN. Afterwards, sensitivity analysis results and coefficient of multiple determination (R2) values of ANN and regression models were compared. Our results show that ANN is more powerful tool than the regression models. 相似文献
14.
The quality of ring spun yarns is largely determined by its level of hairiness. The existence of hairiness inevitably affects
the quality of ring spun yarns. This paper presents an innovative method on lowering the level of hairiness of ring spun yarns.
This can be achieved by shooting compressed air to the yarn, through a swirl nozzle comprising a yarn duct and an airjet nozzle
attached to a traditional ring spin frame. When compressed air is applied from the air-jet nozzle to the yarn duct, the swirling
air flow tucks surface fibers of the ring spun yarns into its body. Four controllable variable parameters for the process,
supplied pressure, nozzle position, twist factor and spindle speed, and their effects on the lowering of yarn hairiness will
be clarified. Their impact on the quality of the yarn is statistically analyzed, and the optimum outcome of the combination
of parameters for the process, will thus be determined. 相似文献
15.
Hanji (Korean traditional paper) yarn displays excellent humidity control, air permeability, and absorbency as well as pleasantness to the touch due to its structural characteristics, and thus, it has been developed as a new eco-friendly fibrous materials. In this study, Hanji, having a basis weight of 8 and 10 g/m2, was prepared using mulberry fibers. The prepared Hanji was cut into Hanji tape of 5–10 mm in width using a rotary slitter and then the tape was twisted to manufacture Hanji yarn. To ensure a uniform twist of Hanji yarn and a smooth twisting process, a water supply system was designed to provide water directly at the twisting zone. At a fixed spindle speed, the feeding speed of the delivery roller was varied to provide different twist numbers for the Hanji yarn. The Hanji yarn manufactured with water treatment has higher tensile properties and a softer touch than the Hanji yarn prepared without water treatment. The Hanji yarns have count numbers of 7–11 Ne and tensile strengths of 1.0–1.2 gf/d. Moreover, the fabric from Hanji yarn shows an excellent color fastness of 4.0 grade, staining of 4–5 to washing, and 4–5 grade to dry cleaning. 相似文献
16.
Jianxin He Yuman Zhou Lidan Wang Rangtong Liu Kun Qi Shizhong Cui 《Fibers and Polymers》2014,15(10):2061-2065
Continuously twisted polyacrylonitrile/viscose nanofiber core-spun yarns were fabricated through novel self-designed multi-nozzle air jet electrospinning set-up. The effect of voltage, solution flow rate, air flow rate and funnel rotating speed on coating rate of core-spun yarn, nanofiber diameter, twist level and mechanical property were discussed. The results showed that polyacrylonitrile/viscose nanofiber core-spun yarns with perfect nanofiber orientation and uniform twist distribution could be obtained at voltage of 32 KV, solution flow rate of 32 ml/min and air flow rate of 1000 ml/min, and the spinning speed could reach to 235.5 cm/min. The diameters of outer coated nanofiber distributed from 100 nm to 300 nm, and nanofiber coating rate could reach to 70.4 %. In addition, the strength and elongation at break increased from 30.82 MPa to 69.65 MPa and from 28.34 % to 43.29 % at the twist angle of 46.6 °, respectively. 相似文献
17.
This paper investigates the influence of raw material and process parameters in spinning that affect the inter fiber cohesion
in yarns. An instrument has been developed for measuring the minimum twist of cohesion. With regard to the raw material parameters,
the influence of different cotton fiber mixings for a given count of yarn is investigated. Also the effect of spinning to
varying counts for a given cotton variety is studied. With regard to the process parameters, studies have been carried out
to investigate the influence of noil extraction in comber, number of draw frame passages, draft pressure in ring frame and
direction of twist. Cohesion improved with increase in the noil extraction percentage in the comber. Increase in the number
of draw frame passages also improved the cohesion. Draft pressure in ring frame improved the fiber cohesion in yarn up to
a pressure of 2.1 kg/cm2. Direction of twist had no effect on the cohesion. 相似文献
18.
Mahbube Sadat Musavi Jad Seyed Abdolkarim Hosseini Ravandi Hossein Tavanai Razieh Hashemi Sanatgar 《Fibers and Polymers》2011,12(6):801-807
The aim of this paper is to investigate vertical wicking in polyacrylonitrile (PAN) electrospinning nanofiber yarn using image
analysis. Colored liquid rising phenomenon into the yarn and the distance of liquid rise were determined as a function of
time. The kinetics of capillary rise follows the Lucas-Washburn equation. The results show that capillary rise rate coefficient
is being reduced with increasing yarn twist, due to the reduction of continuity and size of capillaries. Increasing heat treatment
stretch from 0 % (draw ratio=1) to 50 % (draw ratio=1.5) increases the capillary rise rate coefficient, due to the more homogeneity
of capillary spaces in the yarn structure and increasing heat treatment stretch from 50 to 100 % (draw ratio=2) reduces capillary
rise rate coefficient, because of the low capillary length. The present study indicates that an appropriate choice in production
parameters of nanofiber yarn is all important in obtaining the desired properties of capillary rise. 相似文献
19.
The formation of a symmetric electrospinning triangle zone (E-triangle) via a technique based on using two oppositely charged
nozzles is described for fabricating continuous twisted nanofiber yarn of polyamide (Nylon 66). This study shows how changing
the dimensions and geometry of the E-triangle influences the distribution of nanofiber tension and diameter in this zone,
and consequently how it affects the nanofiber yarn strength. The twist effect on the E-triangle geometry was investigated
by changing the rotational speed of the twister plate of values of 96, 160, 224 and 288 rpm. The results showed that by increasing
the twist rate, the apex angle of the E-triangle increased, whereas the height and width of the Etriangle decreased. An energy
method was adopted to study the distribution of tension on nanofibers in the E-triangle. Considering a constant spinning tension,
it was observed that the gradient of the nanofiber tension curve was steeper and the extreme values of tension on nanofibers
were increased by increasing the twist rate. Furthermore, the mean diameter reduction of nanofibers confirmed these results.
It is concluded that mechanical properties of nanofiber yarn have been considerably improved by increasing the twist rate
and changing the shape of the E-triangle. 相似文献
20.
Studies on reduction of yarn hairiness by nozzles in ring spinning and winding by airflow simulation
Reduction of yarn hairiness by nozzles in ring spinning and winding is a new approach. Simulation of the airflow pattern inside
the nozzles provides useful information about actual mechanism of hairiness reduction. The swirling air current inside the
nozzles is capable of wrapping the protruding hairs around the yarn body, thereby reducing yarn hairiness. Since production
rate of winding is very high and the process itself increases yarn hairiness any method to reduce the hairiness of yarns at
this stage is a novel approach. A CFD (computational fluid dynamics) model has been developed to simulate the airflow pattern
inside the nozzles using Fluent 6.1 software. In this study, both S- and Z-type nozzles having an axial angle of 50° and diameter
of 2.2 mm were used for simulation studies. To create a swirling effect, four air holes of 0.4 mm diameter are made tangential
to the inner walls of the nozzles. S- and Z-twisted yarns of 30 tex were spun with and without nozzles and were tested for
hairiness, tensile and evenness properties. The total number of hairs equal to or exceeding 3 mm (i.e. the S3 values) for
yarn spun with nozzle is nearly 49–51 % less than that of ring yarns in case of nozzle-ring spinning, and 15 % less in case
of nozzle-winding, while both the yarn types show little difference in evenness and tensile properties. Upward airflow gives
best results in terms of hairiness reduction for nozzle-ring and nozzle wound yarns compared to ring yarns. Yarn passing through
the centre of the nozzle shows maximum reduction in S3 values. 相似文献