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1.
The effect of twist level on the mechanical and thermal properties of nylon 66 and polyethylene terephthalate (PET) tyre cords
has been studied. Effects of the twist on some critical cord properties such as tensile properties, shrinkage, shrink force,
adhesion and fatigue have been evaluated. Breaking strength was decreased between 3.1 and 7.3 twist factor values, whereas
breaking elongation was increased, on both nylon 66 and polyester cords. The tensile behaviour of high twist factor PET is
similar to that of low twist factor nylon cords. This is an advantage for the possibility to get closer the properties of
different materials by adjusting theirs twist factors. The shrinkage values increase with increasing twist factor, whereas
shrinks force values decrease for greige nylons and polyester cords. Adhesion and fatigue resistance is increased with increasing
twist factors. 相似文献
2.
The present paper reports the impact of thermal treatment on the characteristics of core-sheath type hybrid technical yarns.
The core-sheath type hybrid yarns are prepared using DREF-III technology. Polyester and glass multifilaments are used as core
components whereas the cotton and polyester staple fibers are the sheath components wrapped around the core filament with
different proportions to form a hybrid structure. The thermal treatment is carried out both in dry and in wet state under
relaxed condition and the thermal shrinkage, sheath-slipping resistance and tensile and bending properties of hybrid yarns
have been studied. Thermal treatment markedly increases the thermal shrinkage and sheath-slipping resistance of hybrid yarns
with polyester multifilament in core, but insignificant effect for yarns with glass multifilament in core. Breaking elongation
of hybrid yarns with polyester multifilament in core increases with treatment temperature. The hybrid yarns with glass multifilament
in core are least affected by thermal treatment. 相似文献
3.
To improve the mechanical properties and the adhesion to a natural rubber (NR)/styrene-butadiene rubber (SBR) matrix, continuous basalt fibre (CBF) cords with and without a silane coupling agent (3-aminopropyl)triethoxysilane (KH550) treatment were dipped into a typical resorcinol-formaldehyde-latex (RFL) system. The breaking force and elongation at break of the cords were tested using a universal testing machine. The adhesive properties were evaluated by both static mode and dynamic (fatigue) mode with H-shape cord-rubber samples. An elastomer testing system was employed to conduct the fatigue test, and the evolution of the adhesive properties between the CBF cord and the NR/SBR matrix was tracked. The interfacial fracture caused by H pull out and fatigue were both observed with a scanning electron microscope (SEM). The results of this investigation show that the RFL-dipping treatment can significantly improve the mechanical properties of the CBF cord and its adhesion to the NR/SBR matrix, and the pre-treatment of the CBF cord with KH550 can further improve the interfacial fatigue property. 相似文献
4.
This research studies the factors which influence the tensile strength of tire cords. Five yarn samples are made by changing
the spinning conditions and viscosity to get various physical properties. Different twisting methods are introduced and the
yarns are twisted under different processing conditions for each twisting process. With the experimental results, various
analyses are performed to find the important factors in retaining strength after the twisting process. SEM and optical microscopic
photographs are taken along with some measurements to assist the analysis. 相似文献
5.
In this study, Nylon 66/Polyester (Ny 66/PET) hybrid cord design and production was investigated to obtain new cord with better
performance than conventional cord. The factors affecting cord properties and cord production process were examined. Taguchi
design of experiment method was implemented in order to minimize the required number of experiments. Different sets of 4 reference
cords conventionally used in tyre industry were prepared and resorcinol-formaldehyde-latex (RFL) treated in order to make
a comparison of performance. Mechanical and thermal properties of hybrid cords were measured and compared with the values
of reference cords. It was found that the twist level of high modulus PET component in the hybrid cords should be the same
or above of the nylon in order to obtain maximum tensile strength. It was observed that shrinkage values of hybrid cords varied
between PET and Ny 66 reference cords. Moreover, for all treated hybrid cords, satisfactory cord-rubber adhesion values were
obtained by using double dip adhesion system. 相似文献
6.
A computational approach is proposed for the mechanical analysis of the multifilament twisted yarn based on the Finite Element
Method (FEM). The physical and the geometrical properties of the filaments and the ideal yarn geometrical structure are considered
for the mechanical modelling. The tensile and bending deformations of yarns are simulated for the prediction of the respective
properties and the computation of the deformed shape. Considerable complexity appears in the mechanical analysis of fibre
assemblies, including the structural multiformity, the material nonlinearity and the large deformation effects occurring.
The FEM applying the beam theory enhanced with advanced solution algorithms approved appropriate for the analysis. Besides
the comparison to an existing analytical model, a set of experimental data derived from 2- to 1200-filament twisted yarns
is used for the evaluation of the accuracy of the proposed approach. The effect of the major structural parameters as the
filament radius and the yarn twist in the elastic properties and the bending rigidity is also examined. 相似文献
7.
This paper reports an experimental study on compressive, flexural and fatigue behavior of polyurethane cast elastomers (PCE) reinforced with warp-knitted spacer fabrics (WKSF). It aims to investigate new applications for these fabrics as the reinforcements for elastomeric parts such as shoe soles, rubber floor coverings, vibration dampening and shock absorbing pads, etc. A series of polyester WKSF with different thickness, structure of outer layer fabric and spacer yarns density was prepared and converted to PCE reinforced WKSF using the hand molding method. All the samples, including the neat PCE, were subjected to static compression, flat and spherical compression, three-point bending and flexural fatigue tests. The results showed that reinforcing PCE with WKSF, considerably enhances its spherical compressive strength (concentrated loading), flexural strength and fatigue resistance. However, it deteriorates flat compressive strength (distributed loading) and recovery behavior after static compression loading. The effect of fiber weight fraction, thickness, structure of outer layer fabric and spacer yarns density on the mentioned properties of the composites was discussed in the paper. 相似文献
8.
The performance of high tenacity nylon 6.6 tyre cords with different linear densities (dtex) was investigated by measuring
some mechanical, structural and physical properties. The structural changes due to the dipping process were analyzed by differential
scanning calorimetry and X-ray diffraction analysis. The breaking strengths were increased with the increasing linear densities,
but decreased with twist level. As the linear density increases, shrinkage values of greige cords were increased. Shrinkage
is mostly dependent on amorphous parts of the cords. Since amorphous parts of the dipped cords are lower than greige cords,
shrinkage values for dipped cord were lower than that of greige cords. Adhesion values were increased with the increasing
linear density and twist level. It has been observed that increasing of the twist levels explicitly improved the fatigue resistance
in the cases 1400 and 1880 dtex cords. But, no significant changes were observed for 940 dtex cords. It has been found that
cords with lower linear densities had better fatigue resistance than that of the cords with higher linear densities. 相似文献
9.
Twisted Copper Filaments (TCF) have been made by a yarn covering process in order to transmit signals and powers for electronic textiles. The 560 den. poly urethane filaments were covered in S-twist direction by urethane-coated copper wires. Two TCF twisted in Z direction were further covered in S direction by PET filaments to make final hybrid structure yarns (HSY). The HSY prepared was proportionally increased in apparent resistance along with measurement length, and showed resistivity of 0.00414 Ω·m. The number of ply was critical in terms of resistance variation, showing a linear increase of resistance with ply number. The twist factor, however, was not so significant without a slight decrease for severe twist level. Resonance Frequency, S11 (reflection), S21 (transmission) were measured and compared in order to examine the feasibility of applying to electrical signal transmission for wearable textiles. As expected, amplitude of resonance frequency was significantly decreased mainly due to increase of capacitance caused by length increase. It has been shown that S11 and S21 has been increased and decreased, respectively due to increase of transmission distance. While resonance frequency has been kept along with the ply number, S11 and S21 were decreased and increased, respectively according to decrease of copper fiber. Final filaments were found to be changed in resonance frequency mainly due to the change of di-electricity and thus capacitance caused by PET covered on it. It have been concluded that while resonance frequency was primarily determined by filament length and dielectric constant of covering yarns, S11 and S21 were mainly determined by measurement length and ply number. 相似文献
10.
In this study, various concentrations of polyethylene terephthalate (PET) polymeric solution were investigated to produce hollow nanofiber yarn. First, the electrospining apparatus was designed in a way that to put PVA multifilament in the core and to twist PET nanofibers onto multifilament yarn as a sheath simultaneously, followed by dissolving PVA yarn in hot water, PET hollow nanofiber yarn was produced. In this survey, it has been observed that the average thickness of sheath increased by increasing concentrations of PET polymeric solution. Results showed that maximum efficiency of extracting the PVA multifilament from the hollow yarn under certain conditions (concentration of 18 % (w/v) of PET, applied voltage of 10 kV, and flow rate of 0.0526 ml/h) was more than 85 %. The mechanical and physical properties of PET hollow yarns were investigated and indicated that the hollow nanofiber yarns at concentration of 30 % and 18 % polymeric solution had the lowest strength and the highest regain moisture, respectively. 相似文献
11.
Mine Akgun 《Fibers and Polymers》2014,15(2):405-413
The effects of some yarn properties (i.e. type, count, twist level, ply number, unevenness and crimp) and fabric constructional properties (i.e. cover, thickness and balance) on surface roughness values of cotton woven fabrics were investigated. A general overview of the results showed that surface roughness values of fabrics were affected from yarn and fabric properties and the effects were related to fabric balance, fabric cover (not cover factor), fabric thickness and crimp values of yarns in fabric structures. Surface roughness values of fabrics decreased as yarn fineness and yarn twist levels increased but as yarn ply number decreased. Also, surface roughness values gradually decreased from open-end yarn constituting fabrics to combed yarn constituting fabrics. Results showed that different properties of yarns caused changes in yarn crimps in fabric structure and also governed the changes in fabric balance, as well as changes in roughness of fabric surfaces. The changing properties of yarns and impact of these properties on fabric construction affected the formation of cotton fabric surfaces from smooth to coarse. 相似文献
12.
采用溶胀法、sEM和力学性能测定,研究了碳酸钙对天然橡胶的补强效果。结果表明,与未改性碳酸钙相比,改性碳酸钙与天然橡胶间具有较强的界面粘合作用 ,改性碳酸钙对天然橡胶具有较好的补强效果,硫化胶的力学性能得到明显的提高。 相似文献
13.
Bidirectional PP/jute yarn eco-composites were fabricated via environment friendly commingling technique and its long term durability/life time was monitored as an effect of accelerated solar ageing on its mechanical properties (tensile & flexural). Accelerated solar ageing promoted the thermal oxidation of PP thus resulting in deterioration of its properties, however; MAPP and KMnO4 treated commingled composites showed much better stability towards thermal oxidation brought about by the solar concentrator, compared to untreated sample and neat polypropylene. This increased resistivity of treated composites (especially MAPP and KMnO4) towards thermal oxidation brought about by the solar concentrator is due to the increased interfacial adhesion between the matrix and jute yarn owing to chemical modifications. The significance of effective stress transfer between the PP matrix and reinforcing jute yarns is evident from the increased tear resistance of PP/jute yarn commingled composites with increasing fibre content and also with different chemical treatments. 相似文献
14.
The fatigue resistance of twelve tubular textile samples designed for use in prototype endovascular devices was tested by
an accelerated fatigue tester. Three time points were selected, namely 0, 26×106, and 100×106 cycles, which are equivalent to 0, 10 months, and 38.5 months implanted in the human body. Changes in tubular diameter, woven
fabric count, thickness, mass per unit area, porosity, water permeability, and bursting strength were selected to characterize
the performance of these samples before and after fatigue testing. The results showed that all the samples experienced some
fatigue during the study, and the evidence of fatigue became more apparent with increasing time. There were clearly observable
relationships between the textile parameters and the fatigue performance of the prototype samples. Woven construction, yarn
size and yarn type all interacted with each other to influence the fatigue performance. Samples with twill weaves fatigued
more readily than those with a 1/1 plain weave. For all three woven constructions, samples with larger yarn size fatigued
more easily. However, the fatigue performance of some samples with multifilament weft yarns is severe. 相似文献
15.
Polylactic acid (PLA) is a biodegradable and compostable polymer obtained from annually renewable resources and is acknowledged to be sustainable and non-polluting polymer with substantial commercial prospective as a textile fiber however, there is lack of literature on apparel applications of this polymer. Therefore in this study it was aimed to develop biobased compostable gloves from PLA draw textured melt spun yarns and to examine the effect of yarn linear density, fabric structure and stitch density on thermo-physiological comfort and moisture management properties of PLA based gloves. 100 % PLA based multifilament yarns of two different linear densities were melt spun and later draw textured on false twist texturing machine to be used for gloves knitting. Single jersey and rib structures were produced with two different stitch densities to investigate their effect on thermal conductivity, thermal resistance, relative water vapour permeability, air permeability and moisture management properties of the gloves. Minitab statistical software was employed to analyze the results of test samples. The coefficients of determinations (R2 values) presented good estimation capability of the established regression models. The outcomes of this research may be useful in determining suitable manufacturing requirements of PLA based gloves to accomplish precise thermo-physiological and moisture management properties. 相似文献
16.
A. M. Manich J. Maillo D. Cayuela J. Gacén M. D. de Castellar M. Ussman 《Fibers and Polymers》2007,8(5):512-519
Polyamide 66 multifilament yarns are textured in order to be endowed the properties of natural staple fibre yarns for textile
applications. Texturing changes crystallinity, orientation and promotes the formation of stable secondary links between the
macromolecular chains. Two polyamide yarns with the same linear density but composed of filaments of different fineness were
textured by the air-jet and the false-twist procedures. The microstructural changes induced by texturing modify the relaxation
behaviour of yarns. By the application of the Nutting’s power law which relates stress, strain and time, the influence of
texturing and filament fineness on the relaxation behaviour of the yarns stretched form 15% to 25% was studied. Relationships
between Nutting’s model parameters and crystallinity, orientation and stability of secondary crosslinks formed during texturing
were also studied. 相似文献
17.
This study examined the effects of the total porosity, pore size, and cover factor on the moisture and thermal permeability of woven fabrics made from DTY (draw textured yarns) and ATY (air jet textured yarns) composite yarns with hollow PET (polyethylene terephthalate) yarns. The wicking of the hollow composite yarn fabrics was found to be superior to that of the high twisted yarn fabrics, which may be due to the high porosity in the hollow composites yarns, but this was not related to the cover factor. The drying characteristics of the hollow composite yarn fabric with high porosity were inferior compared to the high twisted yarn fabrics due to the large amounts of liquid water in the large pores, which resulted in a longer drying time of the fabric. The thermal conductivity of the hollow composite yarn fabrics decreased with increasing measured pore diameter due to the bulky yarn structure. The effects of the hollowness of the yarn on the thermal conductivity were more dominant than those of the yarn structural parameters. The air permeability increased with increasing measured pore diameter but the effects of the cover factor on the air permeability were not observed in the hollow composite yarn fabrics. The effects of porosity on the moisture and thermal permeability of the woven fabrics made from the hollow composite filaments were found to be critical, i.e., wicking and air permeability increase with increasing porosity. In addition, the drying rate increased with increasing porosity and the thermal conductivity decreased with increasing pore diameter, but were independent of the cover factor. 相似文献
18.
Seyedeh Nooshin Banitaba Golchehr Amini Ali Akbar Gharehaghaji Ali Asghar Asgharian Jeddi 《Fibers and Polymers》2017,18(12):2342-2348
This study aims to develop a new approach for fabricating hollow nanofibrous yarns by engineering a triple-layer structure (polyvinyl alcohol (PVA) multifilament core surrounded by a layer of PVA nanofibers and a polylactic acid (PLA) nanofiber outer layer). After fabrication of this 3-layer structure, the core portion was extracted, leaving the outer layer intact after dissolving the PVA nanofibers in water. To determine the optimum thickness of the outer layer, hollow nanofiber yarns with five different thicknesses were produced. A hollow nanofiber yarn was also produced using a common method to enable comparison of the methods. In the common method, a core sheath yarn consisting of a PVA multifilament core and a PLA nanofiber outer layer was fabricated, and a hollow yarn was produced by placing the core yarn in hot water. The results revealed facilitation of core extraction from the yarn body of the new 3-layer structure, which occurred due to rapid dissolution of the middle layer. The wicking behavior in the hollow yarn fabricated using the novel method followed the Locus Washburn equation and that of the hollow yarn produced from the core sheath yarn deviated from it. The results demonstrated that tensile properties of hollow nanofiber yarns were improved by increasing the thickness. Furthermore, hemolysis and cytotoxicity assays indicated that the fabricated hollow nanofibrous structure is non-toxic and blood compatible, indicating its potential for use in biomedical applications such as vascular scaffolds. 相似文献
19.
Farzaneh Rouhollahi Seyed Abdolkarim Hosseini Farzaneh Alihosseini Alireza Allafchian Fatemeh Haghighat 《Fibers and Polymers》2018,19(10):2056-2065
Polyglycolic acid-poly lactic glycolic acid (PGA-PLGA) electrospun nanofibers containing silver nanoparticles have been produced and twisted into the nanofibrous yarn. The morphology of nanofibers and produced yarns, as well as the mechanical properties of the yarns, were investigated. Furthermore, in vitro antibacterial properties and in vitro degradation behavior of yarns containing various silver nanoparticles were studied. SEM images confirmed that the addition of the silver nanoparticles into the polymer solution increases the fiber diameters. The result of the mechanical test of the yarns alone and used in two different forms of the knots was measured and results showed that the strength of the yarns without the knot was significantly more than that of others. The biodegradability test showed that the mechanical properties and the weight of the yarns were quickly reduced after subjecting to in vitro condition. The result of the antibacterial test indicated that the nanofiber yarns containing %3 silver nanoparticles were the most appropriate sample with a considerably antibacterial activity against both gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia Coli with inhibition zones of 8.1 and 9.5 mm, respectively; which demonstrated that silver nanoparticles retained their effectiveness after the electrospinning process. Therefore the nanofibrous yarns containing silver nanoparticles could be successfully produced by the electrospinning process with the proper antibacterial property as a candidate for the surgical sutures. 相似文献
20.
Muhammet Uzun 《Fibers and Polymers》2013,14(10):1714-1721
The paper focuses on the application of ultrasonic energy in textile laundering. In recent years, there has been an increasing interest in ultrasonic energy application in textile industry; however, the effect of ultrasonic laundering on the thermophysiological properties of knitted fabrics has not been studied yet. This study was conducted by using polylactic acid (PLA), cotton, polyethylene terephthalate (PET), and poly acrylic (PAC) fibres containing yarns and their blends. Knitted fabrics, single pique, were made from these yarns by using weft knitting machine. The fabrics were washed ten times for 15 and 60 minutes under 40 °C by using conventional and ultrasonic washing methods. The main aim was to determine the effect of washing methods on the thermophysiological properties of the fabrics. It is also aimed to analyse and evaluate the thermophysiological properties of the PLA fabrics. The incorporation of 100 % PLA and cotton/PLA yarns into single pique knitted fabrics has been attempted to produce for the first time and studied their thermal comfort properties. The results show that the washing processes have a critical importance for the tested fabrics in terms of thermal conductivity, thermal resistance, thermal absorbtivity, water vapour permeability, and heat loss. It has been also demonstrated that the fabric cleaning by using ultrasonic method enhanced the properties of tested fabrics such as thermal conductivity and % recovery. It was also noted that 15 minutes ultrasonically washed fabrics had significantly lower thermal resistance as compared to conventionally washed fabrics. 相似文献