Manufacture technique and electrical properties evaluation of bamboo charcoal polyester/stainless steel complex yarn and knitted fabrics

There are derivative problems of electromagnetic wave radiation accompanying the advances of science and technology nowadays and secure protections are also emphasized gradually. To shield these electromagnetic wave radition jeopardizing people’s health, in this study, stainless steel wires were the core yarn and bamboo charcoal polyester textured yarns were the wrapped yarn. The bamboo charcoal polyester/stainless steel (BC/SS) complex yarns were manufactured using a rotor twister machine. The BC/SS complex knitted fabrics were woven with the complex yarns employing a circular knitting machine. Three manufacture parameters were the wrapped amount of the complex yarn (2 to 6 turns/cm), the lamination amount of the knitted fabrics (1 to 6 layers) and lamination angles of the knitted fabrics (0°/0°/0°/0°/0°/0°, 0°/45°/90°/−45°/0°/45°, and 0°/90°/0°/90°/0°/90°). The knitted fabric exhibited the lowest surface resistance 32.3 Ω/sq. Optimum electromagnetic shielding effectiveness (EMSE) was 45 dB when the knitted fabrics were with 0°/45°/90°/−45°/0°/45° laminating in 0.51 GHz.     

Analysis and off-axis tensile characterization of air-entangled textured polyester woven fabrics depending on unit cell interlacing frequency

The aim of this study is to analyze and determine the off-axis tensile properties of air-entangled textured polyester fabrics based on unit cell interlacing frequency. For this purpose, continuous filament polyester air-entangled textured yarn was used to produce plain, ribs and satin woven fabrics. The fabrics were cut from the warp direction (0°) to weft direction (90°) at every 15° increment, and tensile tests were applied to those of the off-axis samples. The strength and elongation results were introduced to the statistical model developed, and regression analyses were carried out. Hence, the effects of off-axis loading and interlacement on the directional tensile properties of the fabric were investigated. The regression model showed that off-axis loading influences fabric tensile strength. On the other hand, interlacement frequency is the most important factor for fabric tensile elongation. The results from the regression model were compared with the measured values. This study confirmed that the method used in this study as can be a viable and reliable tool. Future research will concentrate on multiaxially directional fabric and the probability that it will result in homogeneous in-plane fabric properties.     

Surface rheological properties of bread dough components in relation to gas bubble stability

The surface rheological properties of dough (components) were determined in order to estimate the effect of these properties on disproportionation and coalescence of gas bubbles in bread dough. Three different systems were studied as a model for the gas-dough interface: a diluted aqueous dough dispersion, gluten and wheat lipids spread on water. The surface dilational modulus, E, and tanϑ of these systems were determined as a function of frequency using a modified Langmuir trough. Values of E and tanϑ found were: 35–100 mN/m and 0·7–0–2, resp., for dough dispersions, 20–45 mN/m and 0·4–0·15, resp., for gluten, and 20–90 mN/m and 1·3–0·1, resp., for lipids in the frequency range tested at room temperature. On the assumption that the gas-dough interface is comparable either to the surface of the dough dispersions tested or to a water surface with spread gluten, it was shown that disproportionation of gas bubbles in dough can be retarded but not prevented. Wheat lipids present in the right concentration in the surface can prevent this foam stabilising mechanism to a larger extent. The surface dilational modulus as well as the surface tension during continuous expansion of dough dispersions were also determined at 45°C. The surface dilational modulus of a dough dispersion at 45°C was 7–25 mN/m, which was approximately 5 times smaller than at room temperature. Results of surface tension measurements during continuous expansion in a Langmuir trough showed that values for surface tension were only slightly higher than at equilibrium (ca. 2 mN/m) at 45°C and at deformation rates of the surface comparable to those at oven rise. These results suggest that thin dough films at higher temperatures will be less stable than at room temperature. Implications in relation with coalescence in dough are discussed. No significant differences in surface rheological properties of dough dispersions of wheats with different bread-making qualities were found in the sinusoidal oscillation tests nor in the continuous expansion tests. Surface rheological properties, therefore, appear not to be the main factor responsible for differences in baking quality amongst different wheats.     

Robust Water-Repellent Treatment of Cotton Fabrics with Polysiloxane Modified via Thiol-Ene Click Reaction

A facile and inexpensive way to prepare self-crosslinkable poly(dimethylsiloxane) (PDMS) for superhydrophobic treatment of cotton fabrics is reported in the study. Through thiol-ene click reaction between mercaptopropyltrimethoxysilane (MPTMOS) and vinyl-containing poly(dimethylsiloxane) (VPDMS), PDMS-g-TMOS can be simply and quickly synthesized. The trimethoxysilane group of PDMS-g-TMOS can react with hydroxyl group on cotton fabric and other -Si(OCH₃)₃ groups. The synthesized polysiloxane (PDMS-g-TMOS) was identified by FT-IR and ¹H-NMR. The morphology of the treated cotton fabric was observed by SEM and XPS was used to analyze the elemental composition on the surface of cotton fabric. The analysis results indicated that the surface was fully covered with PDMS. Due to the low surface energy of PDMS and the rough surfaces of cotton fabric, the optimized water contact angle (WCA) and sliding angle were respectively 154°±0.4° and 14°±0.5°, indicating superhydrophobicity. Moreover, water spray test (AATCC Test Method 22-2010) was also applied to evaluate the water repellency of treated cotton fabric and a score of 90 was assigned according to AATCC Test Method 22-2010. The durability of treated cotton fabric was tested by 50 laundering cycles. The resultant WCA barely decreased and the score of water spray test dropped from 90 to 80, showing the reasonable wash durability.     

Effect of mercerization on mechanical, thermal and degradation characteristics of jute fabric-reinforced polypropylene composites

Jute fabric reinforced polypropylene composites were fabricated by compression molding technique. Fiber content in the composites was optimized at 45 % by weight of fiber by evaluating the mechanical parameters such as tensile strength, tensile modulus, bending strength, bending modulus. Surface treatment of jute fabrics was carried out by mercerizing jute fabrics with aqueous solutions of NaOH (5, 10 and 20 %) at different soaking times (30, 60 and 90 mins) and temperatures (0, 30 and 70 °C). The effect of mercerization on weight and dimension of jute fabrics was studied. Mechanical properties of mercerized jute-PP composites were measured and found highest at 20 % NaOH at 0 °C for 60 min soaking time. Thermal analytical data from thermogravimetric and differential thermal analysis showed that mercerized jute-PP composite achieved higher thermal stability compared to PP, jute fabrics and control composite. Degradation characteristics of the composites were studied in soil, water and simulated weathering conditions. Water uptake of the composites was also investigated.     

Tension and tear behaviors of co-woven-knitted fabric with photograph investigation

Co-woven-knitted (CWK) fabric is a novel structural fabric which combines the woven and knitted structures together. In this paper, the tension and tear properties of CWK fabric along different directions are tested. The stress-strain curves for tension loading and load-displacement curves for tearing loading were well obtained. The high-speed camera also was employed to observe the whole damage process and series of still pictures were picked up to analyze the meso-scale mechanism of CWK fabric along various directions. The results indicated that the tension and tear properties of CWK fabric are closely related to the directions of loading.     

不同角度倒伏对寒地水稻的影响

在大田栽培条件下,为探索和了解寒地水稻不同角度倒伏的变化特征,以寒地水稻垦稻12号为试验材料,比较了不同角度倒伏的寒地水稻植株干物质和形态变化规律,探索了不同倒伏角度水稻的空间部位分布动态变化情况。结果表明:倒伏前期水稻茎鞘干重表现为0°>45°>90°,节间重与节间长度的比值表现为0°<45°<90°。在倒伏前、后两个时期,水稻倒1、2叶片长度以及重量均以0°倒伏的作用强度最明显;而在株高和重心高度上均表现为0°>45°>90°,而在穗长与株高比值上的变化则正好与其相反。综合分析表明,0°倒伏水稻上部空间承受的压力要明显高于其它倒伏角度的水稻。     

Characteristics of Electrical Heating Elements Coated with Graphene Nanocomposite on Polyester Fabric: Effect of Different Graphene Contents and Annealing Temperatures

This paper reports the fabrication of electrical heating elements based on the graphene/waterborne polyurethane (WPU) composite coated on polyester fabric with toughness like that of artificial leather. Samples were prepared with 0, 4, 8, and 16 wt% of graphene by using the knife edge method, and then, the samples were annealed from 100 oC to 160 °C. The graphene content had a large effect on the electrical and electrical heating properties. The surface resistivity was decreased by approximately 6 orders of magnitude with an increase from 0 wt% to 16 wt% graphene/WPU composite fabric. The electric heating properties were also improved, as indicated by the percolation threshold. Samples with various graphene contents were annealed, and it was found that the electrical and electrical heating properties were improved, and the most enhanced properties were obtained when the samples were annealed at 120 °C. The initial modulus and tensile strength were increased in comparison with those of 0 wt% and 16 wt% graphene/WPU composite coated on fabrics, but the elongation at break value was slightly decreased with an increasing graphene content. When the samples were annealed, initial modulus and tensile strength of samples were improved at 120 °C and 140 °C, and they were slightly decreased at 160 °C. However, the elongation at break showed an opposite tendency to the tensile strength. With the increase in content of graphene and annealing at 120 °C and 140 °C, the samples were more stiff and tough, and at 160 °C, the samples were softer. Therefore, graphene/WPU composite coated on polyester fabric by use of the annealing process may have applications in electrical heating elements due to its excellent heating performance and toughness like that of artificial leather.     

High Risk of the Formation of Milky White Rice Kernels in Cultivars with Higher Potential Grain Growth Rate under Elevated Temperatures

Abstract

Our objective was to clarify whether rice cultivars with a higher grain dry-matter increase rate (GIR) under elevated temperature condition show a higher percentage of milky white rice kernels (MWK). The rate of MWK judged using a rice-quality selector significantly varied with the cultivar and experimental year. The spikes of the cultivars detached 5–7 days after heading were solution-cultured with an adequate nutrient supply for one week at 25, 28 and 33ºC. GIR was overall the highest at 28ºC, and GIR at this temperature was considered to reflect the potential GIR in all the grains tested. There was a close correlation between the rate of MWK and the GIR at 28ºC under field conditions when temperatures during the grain-filling period were approximately over 25ºC. It was suggested that cultivars with a higher potential GIR under elevated temperature conditions have a higher risk of the formation of MWK.     

Paper from olive tree residues

An experimental design was performed to study the influence of process variables (135–175 °C for temperature, 60–120 min for pulping time and 15–25% for active alkali) on the properties of pulps (yield, Kappa index, viscosity, 1% NaOH solubles, alcohol–benzene extractives holocellulose, lignin and α-cellulose contents and brightness) and paper sheets (stretch index, burst index, and tear index) obtained from olive trimming residues. Obtaining pulps with acceptably high physical and chemical properties entails operating at a temperature of 175 °C for 90 min and 25% of active alkali. The paper sheets obtained from olive trimming residues pulps that were produced in different degrees of refining are characterised for their stretch index, burst index, and tear index. An increase in the different parameters for the paper sheet upon increasing the degree of refining is found. All pulps reached between 33 and 39 kN m/kg in the stretch index, between 1.5 and 2 kN/g for the burst index and 0.7–2.5 N m²/g for the tear index and not in excess of the refining degree (<45 °SR).     

Numerical Simulation of Tensile Behavior of 3D Orthogonal Woven Composites

In this paper, the composite reinforced with three dimensional orthogonal woven fabric/epoxy resin was fabricated with vacuum assisted resin transfer model. The tensile behavior in 0° and 90° directions were experimentally executed. The tensile behavior of 3D orthogonal woven composite was numerical simulated based on the unit cell model and compared with the experimental result, the influence of crack damage and stress on fiber, resin and fiber/resin interface was analyzed. The maximum differences between experimental and simulated results are 3.23 % and 7.94 %. The verified model can be used to simulate the other static and dynamic mechanical properties and analyze the influence of the behavior of component material on the mechanical material properties of 3DOWC.     

Multifunctional,Hydrophobic and Flame-retarded Cotton Fabrics Modified with Liner Piperzine/Phosphorous/Polysiloxane Copolymer

α,ω-di[(4-butoxy-piperazin-1-yl)-phosphinic acid methyl ether]-terminated linear polysiloxane (PNPDMS) was synthesized and utilized as the flame retardant and hydrophobing agent. The flame retardance and thermal decomposition behaviors of cotton fabrics were systematically estimated by limiting oxygen index (LOI), thermogravimetric analysis and vertical burning test, respectively. It was found that the LOI of cotton fabric treated with PNPDMS enhanced to 29.82 % compared with cotton fabric without treatment, whose LOI was only 18.00 %. The treated cotton fabric showed a shorter char length, a shorter After-flame time, and no After-glow time as revealed in vertical burning test. The mechanical property in treated cotton fabric was slightly decrease. Furthermore, the grade of water repellency of treated cotton fabric reached to 90 and water contact angle (WCA) increased to 141.90° compared with cotton fabric without treatment whose WCA was 62.80°. The result showed that the cotton fabric treated with PNPDMS exhibited excellent flame retardance and hydrophobic properties.     

Influence of temperature on the bending properties and failure mechanism of 3D needle-punched carbon/epoxy composites

This paper presents the three-point bending properties of 3D needle-punched composites with two fiber architectures at room and elevated temperatures. The influences of temperature and fiber architectures on the load/deflection curves, bending strength and bending stiffness are analyzed. Macro-Fracture morphology and SEM micrographs are examined to understand the damage and failure mechanism. The results show that the bending properties of plain structure needle-punched composites are superior to those with non-woven structure. Meanwhile, the bending properties of composites decrease significantly with the increase of testing temperature. Moreover, the damage and failure patterns of composites vary with fiber architecture and testing temperatures. For the plain structure, 90 ° and 0 ° fiber bundles can bear the load together. At room temperature, the composite shows brittle fracture feature and exhibits local damage with matrix cracking, breakage and tearing of the fibers. While at a higher temperature, the composite shows less fracture and becomes more softened and plastic. It damages with matrix cracking, falling off and plastic deformation, fiber layer/web delaminating, and interface debonding.     

Vibration damping of flax fibre-reinforced polypropylene composites

This work investigates the effects of fibre content and fibre orientation on the damping of flax fibre-reinforced polypropylene composites. Laminates of various fibre contents were manufactured by a vacuum bagging process; their dynamic behaviour were then found from the vibration measurements of beam test specimens using an impulse hammer technique to frequencies of 1 kHz. The frequency response of a sample was measured and the response at resonance was used to estimate the natural frequency and loss factor. The single-degree-of-freedom circle-fit method and the Newton’s divided differences formula were used to estimate the natural frequencies as well as the loss factors. The damping estimates were also investigated using a “carpet” plot. Experiments were subsequently conducted on a range of samples with different fibre volume fractions and orientations. The results show significant variations in natural frequencies and loss factors according to the variations in fibre orientation. Composites containing 45°, 60° and 90° fibre orientation exhibit approximately the same natural frequencies. Composites with differing fibre orientations exhibit different loss factors for the various modes of vibration, and the maximum loss factor is obtained for the case of 45° fibre orientation, with the loss factor generally lying in the range of 2-7 %. It was found that the loss factor increases with increasing frequency and decreases slightly with increasing fibre content. These outcomes indicate that flax fibre-reinforced composite could be a commercially viable material for applications in which noise and vibration are significant issues and where a significant amount of damping is required.     

Dyeing and fastness properties of a reactive disperse dye on PET, nylon, silk and N/P fabrics

Dyeing and color fastness properties of a reactive disperse dye containing an acetoxyethylsulphone group on PET, Nylon, silk and N/P fabrics were examined. The reactive disperse dye exhibited almost the same dyeing properties on PET fabric as a conventional disperse dye except the level of dye uptake. The most appropriate pH and dyeing temperature for the dyeing of Nylon fabric were 7 and 100°C respectively. The build-up on Nylon fabric was good and various color fastnesses were good to excellent due to the formation of the covalent bond. Application of the reactive disperse dye on silk fabric at pH 9 and 80°C yielded optimum color strength. The rate of dyeing on Nylon fabric was faster than that on PET fabric when both fabrics were dyed simultaneously in a dye bath, accordingly color strength of the dyed Nylon was higher. The reactive disperse dye can be applied for one-step and one-bath dyeing of N/P mixture fabric with good color fastness.     

Analysis and construction of a quality prediction system for needle-punched non-woven fabrics

In this study, polyester and polypropylene staple fibers were selected as the raw material, and then processed through roller-carder, cross-lapper and needle-punching machine to produce needle-punched non-woven fabrics. First, the experiment was planned using the Taguchi method to select processing parameters that affect the quality of the needle-punched non-woven fabric to act as the control factors for this experiment. The quality characteristics were the longitudinal and transverse tensile strength of the non-woven fabric as well as longitudinal and transverse tear strength. The L₁₈ (2¹×3⁷) orthogonal array was selected for the experiment as it offered an improvement on the traditional method that wastes a lot of time, effort and cost. By using the analysis of variance (ANOVA) technique at the same time, the effect of significant factors on the production process of needle-punched non-woven fabrics could be determined. Finally, the processing parameters were set as the input parameters of a back-propagation neural network (BPNN). The BPNN consists of an input layer, a hidden layer and an output layer where the longitudinal/transverse tensile and tear strength of the non-woven fabric were set as the output parameters. This was used to construct a quality prediction system for needle-punched non-woven fabrics. The experimental results indicated that the prediction system implemented in this study provided accurate predictions.     

Fabrication of hydrophobic/oleophilic cotton fabric by mussel-inspired chemistry for oil/water separation

A straightforward approach was proposed to modify cotton fabric for oil/water separation based on musselinspired reaction. The poly(DMA-Octadecyl acrylate) was designed to contain key chemical constituents present in mussel adhesive proteins by free radical polymerization of dopamine hydrochloride and octadecyl acrylate, which strongly adsorbed to fabric substrates, providing a special surface for fabric. The chemical structure, surface topography, and surface wettability of the fabric were characterized. The results showed that as-prepared cotton fabric displayed a high CA of >150° when dripped water droplets were on the modified fabric surface, and the oil contact angle (OCA) was close to 0°, it had excellent potential to be used in practical applications and has created a new method of fabric modification for oil/water separation.     

Effect of temperature and activators on the characteristics of activated carbon fibers prepared from viscose-rayon knitted fabrics

This study used viscose rayon-based knitted fabric, pre-treated by a composite flame retardant, as the precursor. The fabric then underwent oxidation, carbonization and activation in a semi-open high-temperature erect furnace to produce Activated Carbon Fabrics (ACF). The microstructure and chemical properties of the ACF were obtained under carbonization temperatures of 600–1000 °C and by different activation sources. The results showed that the ACF produced was mainly of a microporous structure. When the carbonization temperature was increased, the production rate dropped while both the true density (D_He) and crystallization thickness increased. In addition, ACF prepared using steam, plus water as the activation source, has a larger specific surface area, greater crystallization thickness and a higher true density (D_He).     

Synthesis of a novel flame retardant containing phosphorus-nitrogen and its comparison for cotton fabric

A new charring agent, a derivative of cyanuric chloride, mono-substituted, dimethyl (4,6-dichloro-1,3,5-triazin-2-yloxy)methylphosphonate (CN), was synthesized in good yield and characterized. Its flame retardant and thermogravimetric properties were compared to those of the di-substituted compound, tetramethyl (6-chloro-1,3,5-triazine-2,4-diyl)bis(oxy)bis (methylene)diphosphonate (CN-1), which was prepared in previous work. All untreated fabric showed limiting oxygen index (LOI) values of about 18 vol% oxygen in nitrogen. Fabrics treated with CN at 5?C21 wt% add-ons had high LOI values of 30?C40 vol%, while fabrics treated with CN-1 at 5?C19 wt% add-ons had low to high LOI value of 20?C36 vol%. In 45° angle flammability tests, all treated fabrics with CN and CN-1 were passed and some fabrics were not igniting at all. Thermal degradation revealed that onset of degradation and the char yield of CN compound is higher than that of CN-1. Treated fabric with CN, 21 wt% add-on, had an onset of degradation of 240 °C, while fabric treated with CN-1, 19 wt% add-on displayed an onset of degradation of 230 °C. Despite the differences in onset temperature, the two samples provided almost the same char yield at 600 °C, 35 and 36 %. With Fourier transform infrared (FTIR), samples of treated/unburned and treated/burned of CN and CN-1 showed the same functional groups and revealed the disappearance of triazine group and P-O-methyl after burning. Additionally, scanning electron microscopy (SEM) showed that both CN and CN-1 acted as flame retardants by the same mechanism and characterized the surface morphology of the flame retardant treated twill fabrics.     

Superhydrophobicity,Self-cleaning and Flame Retardancy Properties of Cotton Fabric

A simple and facile method for fabricating the cotton fabric with superhydrophobicity, self-cleaning and flame retardancy was described in the present work. Three types of antimony pentoxide sol (Sb₂O₅), aluminum hydroxide sol (Al(OH)₃) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (fluoroalkyl silanes) were used as coating for the cotton fabric. It was found that Sb₂O₅ and Al(OH)₃ exhibited significant synergistic effects on the flame retardancy. When the weight ratio of Sb₂O₅/Al(OH)₃(content 30 wt%) was 1:3, the results showed that the limiting oxygen index (LOI) value was 45.1 %, smoke density (SDR) value was 35 %, and it still passed UL94 V-0 rating. The cotton fabrics coated with fluoroalkyl silanes/Sb₂O₅/ Al(OH)₃ showed a superhydrophobicity, anti-contamination and self-cleaning properties. In addition, the results exhibited the outstanding superhydrophobicity, oil/water separation, excellent waterproofing durability and flame retardancy of cotton fabric after 1000 cycles of washing by water, the LOI value was 40.1 %, SDR value was 39 % and WCA was 152° after 1000 cycles of washing. We believe that this simple, environmentally friendly and versatile fabrication of the cotton fabric had excellent real-life applications.