Woven Mesh Research Articles

Thermo-mechanical performances of elastic–porous materials with metallic wire mesh structures

Elastic–porous lightweight materials with metallic wire mesh structures are increasingly being used for vibration–reduction and thermal conduction under high temperatures or other harsh conditions. This is attributed to their special meso–scale functional structures. However, little is known about the intrinsic relationship between thermo-mechanical performances and the porous structure. We synthesized elastic–porous materials with metallic wire mesh (EPMWM) structures using entangling and weaving technologies. In addition, numerical models of microstructures were established, and experimentally validated using quasi–static and dynamic tests. Theoretical and experimental analyses of heat transfer behavior showed that the damping energy consumption of the entangled metallic wire mesh structure was better than that of the woven metallic wire mesh structure to a certain load condition. Moreover, pore air in EPMWM significantly affected the overall thermal conductivity, especially at high temperatures, due to the heat radiation between metallic wires.

Transparent, High‐Charge Capacity Metal Mesh Electrode for Reversible Metal Electrodeposition Dynamic Windows with Dark‐State Transmission <0.1%

AbstractDynamic windows allow user control over light and heat flow to save energy and maximize comfort. Reversible metal electrodeposition (RME) dynamic windows can uniquely tint to a color‐neutral privacy state (0.1% visible light transmission). The design parameters of transparent metal mesh counter electrodes for high‐contrast RME dynamic windows: high transparency, charge capacity and surface area with low haze, sheet resistance and cost are discussed, concluding that woven metal meshes meet these design parameters. Electroplated current is measured on an indium tin oxide electrode and two meshes with different wire spacings, showing the meshes’ cylindrical geometry enable them to draw more current per square area. The mesh material composition is analyzed to ensure cycling durability in a CuBi electrolyte by developing a transparent mesh with an inert core (stainless steel, SS), a thin Au coating, and a high charge‐capacity (1.5 C cm−2) CuBi outer coating. The study demonstrates that the films maintain a consistent Cu:Bi ratio and optical properties after 250 privacy cycles or 1500 cycles to 10% transmission, showing that the Cu and Bi coating is effective in keeping the films from becoming Cu rich with cycling. Finally, a 100 cm2 device with excellent uniformity and color neutrality is demonstrated.

Cryogenic performance of a compact high-effectiveness mesh-based counter-flow heat exchanger

Compact effective Counter Flow Heat EXchangers (CFHEX) are critical components of almost all thermodynamic cycles, e.g. cryocooler-based remote cooling circuits that can enable a large number of high technology cryogenic applications. It is essential for such applications that these CFHEXs match the overall performance of the system. This paper presents the test setup, experimental performance results and the analysis of a novel mesh-based CFHEX in the 50 K–290 K temperature and 1 bar–5 bar pressure ranges. The measurements are compared to the numerical predictions for a range of mass flow rates and fluid stream pressures. A maximum average effectiveness of 94.9 % (NTU = 18.6) is achieved with a combined pressure drop of only 15 mbar at nominal system operating conditions with helium gas. The static loss along the CFHEX is measured and analysed. The numerical model is correlated with the experimental findings and further improvements to the design are suggested. In addition, a new friction factor model is proposed for the woven mesh matrix. Global implications of the CFHEX performance on the remote cooling system are quantified and discussed.

Numerical analysis of real-scale reverse electrodialysis with microscale structures and electrode segmentation

Here we present an improved numerical method by exploiting periodicity to analyze a real-scale reverse electrodialysis (RED), including an unlimited number of microstructures and electrode segmentations. Flow and current (or voltage) distributions are calculated for a unit cell with on-demand adjustment of applied voltage (or current), and the calculations are repeated by mapping the outflow's data to the inflow’s one. By laying end to end those results, a real-scale RED with vast microstructures and segmented electrodes can be simulated. 4-mm length RED was analyzed by exploiting periodicity and a conventional method, and we verified that the errors were within 1%, requiring 1/n memory usage and < 50% computing time (n: number of repeating units). Such reduced computational cost allows us to calculate 400-mm length RED filled with 4,000 microstructures of woven mesh spacer, 2D horizontal or 3D cross patterns and 10 segmented electrodes. We confirmed that the relative superiority of the local power generation of spacers/patterns varies from location, and the net power density (and net energy efficiency) can be enhanced up to 251 % by optimizing a system’s size and 352 % by electrode segmentation. In addition, we verified that the degree of performance enhancement as segmenting the electrode is proportional to the Sherwood number, which represents the convective mass transfer governed by a flow velocity and spacer/pattern structures. To be best of our knowledge, this is the first numerical analysis of a real-scale RED with spacer/patterns and electrode segmentations simultaneously, and it firmly established the existence of coupled effects of patterns and electrode segmentation.

Reverse osmosis membrane compaction and embossing at ultra-high pressure operation

Herein, we describe the performance (i.e., flux and rejection) of commercially-available, thin film composite brackish water RO (BWRO), seawater RO (SWRO) and high-pressure RO (HPRO) membranes operating at pressures from 14 bar (200 psi) to 207 bar (3000 psi). For each membrane material, we elucidate the impacts to performance using a porous metal frit and woven tricot mesh permeate carrier materials from commercial HPRO, SWRO, BWRO and tap water RO (TWRO) membrane modules. The water permeability of all tested membranes declines with increasing pressure, whereas rejection behaves differently for different combinations of membrane type and permeate carrier. Cross-sectional SEM and FIB-SEM images confirm permanent reduction of the polysulfone support membrane thickness (38% to 60%) as well as collapse of support membrane skin layer pores – both of which may contribute to the observed performance decline. Also, at ultra-high pressures, permeate carrier materials with higher porosity cause greater embossing and, ultimately, coating film damage (defect formation) that leads to increased salt passage (loss of salt rejection). In contrast, the permeate carriers with lower porosity still lost water permeability, but maintained higher rejection. Finally, all of the observed compaction/embossing-related performance decline occurs within about 60 min after a membrane coupon was exposed to ultra-high pressure.

Can Nonwoven Tea Bags Be Used to Determine the Tea Bag Index?

Researchers have studied the impact of various anthropogenic activities on litter decomposition rates because of their large impact on the future carbon budget and climate change. However, any assessment of the global-scale impact of anthropogenic activity on litter decomposition requires standardized methods that can exclude the variability of litter chemistry. The Tea Bag Index (TBI) is widely used as a standardized method to obtain both the decomposition constant k of early-stage litter decomposition and the stabilization factor S. Recently, a tea bag manufacturer changed the materials and size of the tea bag mesh from a 0.25 mm woven mesh to a nonuniform, nonwoven mesh. To test whether these changes in mesh materials have any effect on the TBI approach, an incubation study was performed. Obtaining time series decomposition data for both green and rooibos teas, two essential assumptions of the TBI approach were examined: (i) that most of the unstabilized hydrolyzable fraction of green tea is decomposed within 90 days (unless the environment is unfavorable for decomposition) and (ii) the S of green tea is equal to that of rooibos tea. The results did not show a clear breakdown of the first assumption of the TBI approach due to the changes in mesh materials, and they did not support the second assumption. The S of rooibos tea determined by fitting an asymptote model to the time series data was significantly larger than the TBI-based S. In conclusion, the TBI may be undeterminable using nonwoven tea bags.

Chemical absorption of CO2 in alkaline solutions using an intensified reactor

AbstractCapturing carbon dioxide (CO2) emissions from point sources is critical for a sustainable chemical industry. Several techniques have already been developed and the race is ongoing to meet more stringent limitations at lower operating costs. This study presents the capability of a novel, flexible reactor to achieve high absorption rates at very low power consumption. CO2 absorption in an aqueous sodium hydroxide (NaOH) solution was used as a benchmark. An air–CO2 stream made of 30% v/v CO2 was injected co‐currently with the aqueous alkaline solution in a tubular reactor equipped with woven mesh mixers. The removal efficiencies were measured along the length of the reactor, which operated at total mean flow velocities ranging between 1–2 m/s and gas phase holdups between 10%–30%. Four different mixer geometries were also tested, and the results were analyzed based on the operating conditions and reactor design configurations. While these studies can be further optimized and potentially applied in carbon capture operations, it was found that more than 96.5% of the CO2 could be removed using different combinations of mixer geometry and operating conditions. This high removal efficiency was reached within a residence time of 400 ms at a low cost of 23.65 .

A monolith electrode featuring FeS2 embedded in porous carbon nanofibers for efficient hydrogen evolution

Constructing electrode materials embracing with high effectivity and durable stability is of vital importance for hydrogen evolution reaction (HER) in electrochemical water splitting. Herein, a monolith electrode is designed with FeS2 nanoparticles embedded in porous carbon nanofibers (FeS2@CNFs) via an in-situ electrospinning strategy, which is directly used as an efficient electrode for HER without any extra-substrates. Such monolithic electrode eliminates interface problems between active catalysts and carriers and expends more intrinsic catalysis regions, which effectively shortens the pathway of electron/ mass transport. The FeS2@CNFs electrode displays good HER activity only with an overpotential of 168 mV at 10 mA cm−2. It is worth noting that this monolith electrode shows the excellent HER stability for nearly a week in 1 M KOH without any destruction of fibrous structure. Such considerable activities can be ascribed to the interwoven nanofiber-meshes that engineer the self-supportive architecture with stable strength and the carbon-encapsulation structure that prevents FeS2 from collapsing. The woven meshes and porous structure allow the sufficient penetration of electrolyte and fast gas diffusion. This work provides a valuable reference for rationally designing a monolith electrode effectively for gas-involved electrochemical application.

Mesh patterned electrolyte supports for high‐performance solid oxide fuel cells

In this study, the surface of solid oxide fuel cell electrolyte is decorated with different patterns by mesh pressing to improve the cell performance by increasing the surface area of electrolyte–electrode interfaces. Six various woven and unwoven metal meshes with different mesh gaps are considered in this respect. The patterned electrolyte surfaces are scanned by a profilometer to obtain the surface properties created by each mesh. Electrolyte supported cells are fabricated and tested to investigate the effects of electrolyte surface patterning on the cell performance. A cell with a flat electrolyte support is also manufactured and tested as a reference case. Impedance analyses are performed for a detailed examination beside microstructural observations via a scanning electron microscope. Under the same lamination conditions, woven meshes provide surface patterns with relatively higher average roughness values. Among the cases studied, the cell treated with a woven mesh having 0.57-mm wire diameter and 2-mm mesh gap on a side exhibits the highest maximum performance of 0.626 W cm−2 at 800°C, whereas that of the reference cell is only 0.320 W cm−2, indicating that the performance of the reference cell can be almost doubled by the simple method suggested in this study. The impedance results show that the improvement in the cell performances is due to reduced electrode polarizations and ohmic resistance via mesh pressing, resulted from increased surface area of electrode–electrolyte interfaces and partially reduced electrolyte thickness as confirmed by microstructural observations, respectively.

Durability performance of geopolymer ferrocement panels prepared by different alkaline activators

Ferrocement is a composite material consisting of a steel mesh bonded mortar used to form thin sections in numerous applications. Corrosion of ferrocement is more critical than the conventional reinforced concrete because of the small diameter of wire mesh and small concrete cover. This study aims to investigate the durability of fly ash-based geopolymer ferrocement composites. The accelerated corrosion test was conducted on ferrocement panel specimens with various affecting parameters. Series of ferrocement panel specimens were cast. The studied parameters included; type of steel wire mesh (welded, woven and expanded), thickness of panel specimens (20, 25 and 30 mm), number of mesh layers (1, 2 and 3 layers) and type of mortar mixtures. Four geopolymer (GP) mortar mixes were prepared with four different alkaline solutions. The alkaline solutions were a mixture of sodium silicate (NS), sodium hydroxide (NH), potassium silicate (KS) and potassium hydroxide (KH) as NS + NH, NS + KH, KS + NH and KS + KH. Parallel with the investigated GP mixture, a Portland cement mix was prepared. All mortar mixes were exposed to different aggressive environments including 5% sulphuric acid (H2SO4) and sodium sulphate for 24 weeks as well as water absorption test was conducted. Test results indicated that using a thicker steel mesh such as woven mesh, a thicker mortar cover and more than one layer in ferrocement panel specimens provides more resistance against reinforcement corrosion. The investigated GP mortar mixes provide a good passivation protection than cement mortar. Moreover, the fly ash-based GP mortar activated by NS showed passivation protection of steel wire mesh greater than the fly ash-based GP mortar activated by KS and showed a higher resistance to sodium sulphate and sulphuric acid exposure.

Dynamic Membranes for Enhancing Resources Recovery from Municipal Wastewater.

This paper studied the feasibility of using dynamic membranes (DMs) to treat municipal wastewater (MWW). Effluent from the primary settler of a full-scale wastewater treatment plant was treated using a flat 1 µm pore size open monofilament polyamide woven mesh as supporting material. Two supporting material layers were required to self-form a DM in the short-term (17 days of operation). Different strategies (increasing the filtration flux, increasing the concentration of operating solids and coagulant dosing) were used to enhance the required forming time and pollutant capture efficiency. Higher permeate flux and increased solids were shown to be ineffective while coagulant dosing showed improvements in both the required DM forming time and permeate quality. When coagulant was dosed (10 mg L−1) a DM forming time of 7 days and a permeate quality of total suspended solids, chemical oxygen demand, total nitrogen, total phosphorous and turbidity of 24 mg L−1, 58 mg L−1, 38.1 mg L−1, 1.2 mg L−1 and 22 NTU, respectively, was achieved. Preliminary energy and economic balances determined that energy recoveries from 0.032 to 0.121 kWh per m3 of treated water at a cost between €0.002 to €0.003 per m3 of treated water can be obtained from the particulate material recovered in the DM.

ЧИСЛЕННО-ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ НЕЛИНЕЙНОГО СЖАТИЯ ПАКЕТОВ МЕТАЛЛИЧЕСКИХ ПЛЕТЕНЫХ СЕТОК

The results of numerical simulation of elastoplastic compression of symmetrical fragments of a package of woven steel meshes are presented. The thickness of the symmetrical fragment is one and two layers. The study was carried out under dynamic loading conditions in the ANSYS LS-DYNA computer system. The mesh package is formed by superimposing layers on top of each other while maintaining the direction of the wires. The packet has a quasi-periodic structure; therefore, symmetrical fragments can be distinguished. For two mesh layers, a fragment is accepted, taking into account the shift of the layer in the lateral directions by half the size of the cell. The compression was carried out by a pair of absolutely rigid plates moving symmetrically towards each other at a constant speed for a given time interval. A multilinear plasticity model with isotropic hardening was used to describe the behavior of the material. If the maximum specified deformation is exceeded in the calculation, the diagram automatically continues with a small linear hardening modulus. A comparative analysis of numerical solutions for the compression of symmetrical fragments from one and two layers of a woven mesh is carried out. When the fragments are compressed, a strongly uneven stress-strain state arises in the wires, especially large irreversible deformations occur in the knots of weaving. The deformation curves of the fragments have characteristic inflections associated with the fact that the deformation process includes not only knots of weaving, but also deformations of wire compression along its entire length. The numerical results are compared with the experimental dynamic compression curve of a multilayer mesh package. The compression curves are different for one and two layers. For two layers of grids, the deformation curve at low pressure is more consistent with the experimental data. Two stages of behavior of the deformation diagram are observed at low and high degrees of compression, the characteristic inflection is formed somewhat earlier than in the numerical solution for one layer. Numerical dependences of the relative area of the normal and lateral passage sections of a symmetrical fragment of a mesh package on the compression strain are obtained. These data can be used to simulate the propagation of shock waves through multilayer woven mesh packages.

Anomaly Detection on Textured Images with Convolutional Neural Network for Quality Control of Micrometric Woven Meshes

Industrial woven meshes are composed of metal material and are often used in construction, industrial and residential industries. The context of this work is defect detection in industrial fabrics in the quality control process. It is often performed with a manual method and could be quite tedious and time-consuming. We propose here a method to automatically detect defects in micrometric steel meshes using a Convolutional Neural Network. The database used for this work comes from the real problem of anomaly detection on micrometric woven meshes. This detection is performed through supervised classification with Convolutional Neural Network using a VGG19 architecture. To this aim, we propose a pipeline and a strategy to tackle the small amount of data. It includes i) augmenting the database with translation, rotation and symmetry, ii) using pre-trained weights and iii) checking the learning curve behaviour through cross-validation. The proposed method has been evaluated by automatically detecting if metallic fabrics has defects. Obtain results show that, despite the small size of our databases, detection accuracy of 96% was reached.

Selection of factors and preparation of an experiment planning matrix for modeling a filter material with an orthotropic structure based on woven meshes

The advantages of a filtering material with an orthotropic structure (FMTS) consisting of a package of woven meshes are described. Information is given on the first stage of FMTS modeling, which includes the choice of parameters and factors of the experiment and the compilation of a planning matrix to establish the relationship between technological characteristics and properties of FMTS. When constructing a stochastic mathematical model at this stage, two factors were chosen to describe the properties of the material – qualitative (mesh type), specified by the sigma constraint method, and quantitative (package thickness). The constructed matrix of experiment planning is given. The natural and coded values of FMTS samples were determined.

Evaluation of Crosslinking Conditions on the Properties of Chitosan Woven Meshes

Evaluation of Crosslinking Conditions on the Properties of Chitosan Woven Meshes

Fabrication of Au-Nanoparticle-Decorated Cu Mesh/Cu(OH)2@HKUST-1 Nanorod Arrays and Their Applications in Surface-Enhanced Raman Scattering

Here we report a simple fabrication method for large-scale hybrid surface-enhanced Raman scattering (SERS) active substrates composed of Au-nanoparticle-decorated three-dimensional (3D) Cu(OH)2@HKUST-1 (Cu3(btc)2, H3btc = 1,3,5-benzenetricarboxylic acid) nanorod arrays on a woven Cu mesh (Cu mesh/Cu(OH)2@HKUST-1@Au). Cu(OH)2 nanorods were first obtained from a simple in situ chemical engraving Cu mesh and then utilized as self-sacrificing templates to achieve HKUST-1 nanocube-assembled nanorods; finally, Au nanoparticles (Au NPs) were sputtered onto the Cu(OH)2@HKUST-1 nanorods. Due to the large surface area, the three-dimensional Cu mesh/Cu(OH)2@HKUST-1 nanorods could load high-density Au NPs and capture target detection molecules, which is beneficial to the formation of a strong electromagnetic field coupling between Au NPs, and provides abundant “hot spots” for a sensitive and uniform SERS effect. Using the Cu mesh/Cu(OH)2@HKUST-1@Au nanorod arrays as the SERS substrate, 10−9 M Rhodamine 6G and 10−8 M 4-aminothiophenolcan were identified. To verify their practical application, the fabricated arrays were employed as SERS substrates for the detection of thiram, and 10−8 M thiram could be recognized. The hybrid SERS substrates show potential applications in the field of environmental pollutant detection and this is of great significance to the sustainable development of the environment.

Production of PP Composites Reinforced with Flax and Hemp Woven Mesh Fabrics via Compression Molding

Hemp and flax fibers are among the most interesting vegetable fibers that can be used to reinforce polymeric matrices. In line with the global environmental requests, the use of these fibers especially coupled with thermoforming polymers are increasing more and more in order to expand their applications and replace synthetic fibers and thermosetting plastics. However, one of the major limitations of vegetable fibers is their poor adhesion with polymeric matrices that is often overcome by fibers chemical treatments or by using coupling agents within the matrix. Aiming to produce polypropylene (PP) bio composite laminates reinforced by hemp and flax fibers without additional process steps, this paper deals on the study of their production via the compression molding technique by using woven fabrics characterized by a large mesh size able to ensure a mechanical anchoring between fibers and matrix. Two different forming strategies that differ in the time required for reaching the maximum values of compression pressure and in the dwelling time at this value were used in order to investigate how the yarn impregnation was affected by them. To expand the applications of composites under investigation, tensile, bending, Izod, heat deflection temperature (HDT) and bearing tests were carried out. The results highlighted how the use of a waiting time before the reaching of the maximum moulding pressure allowed a better matrix flow within the vegetable yarn leading to higher mechanical performances.

Numerical evaluation of the retrofit effectiveness for polyurea-woven glass fiber mesh composite retrofitted RC slab subjected to blast loading

Polyurea (PU), which has a high elongation and energy absorption, is widely used as a retrofitting coating for building structure. However, the load-carrying capacity and flexural stiffness of the PU retrofitted structure cannot be fully enhanced under blast load as the low stiffness of the PU coating. To overcome this drawback, the woven glass fiber mesh (WGF) was selected as a 'soft rebar' to combine with PU to form a PU-WGF composite coating. Firstly, three reliable finite element (FE) models based on field explosion test setup were developed using LS-DYNA and verified according to the test data. Then, parametric analyses, comparison analysis and damage assessment were conducted by numerical simulation methods, where the developed models were verified by the field explosion tests. Results show that WGFs can increase the energy absorption of PU coating to 2.5 times, and downgrade the damage degree of its retrofitted RC slab, especially a collapse and severe damage occurs in it. On the contrary, the PU coating can hardly achieve this goal, which is mainly used to prevent the spalling of the explosion concrete fragments.

The Structural Effect of Electrode Mesh on Hydrogen Evolution Reaction Performance for Alkaline Water Electrolysis

Alkaline water electrolysis (AWE) is a mature water electrolysis technology that can produce green hydrogen most economically. This is mainly attributed to the use of Ni-based materials that are easy to process and inexpensive. The nickel-based meshes with various structures such as woven mesh and expanded mesh are widely used as electrode in the AWE due to its common availability and easy fabrication. However, the morphological effect of meshes on hydrogen evolution reaction (HER) performance has not been studied. Here a new parameter to determine the structural effect of mesh on HER performance was first proposed. The key factors of the parameter were found to be the strand width, pore width and the strand surface area. The woven mesh with the ratio of pore width to strand width that converges to 1 showed the lowest the overpotential. The expanded mesh with the higher the structural surface area exhibited the lowest the overpotential. This study will help to choose an optimal structure for the mesh with the HER electrode.

Design and production of the high voltage electrode grids and electron extraction region for the LZ dual-phase xenon time projection chamber

The dual-phase xenon time projection chamber (TPC) is a powerful tool for direct-detection experiments searching for WIMP dark matter, other dark matter models, and neutrinoless double-beta decay. Successful operation of such a TPC is critically dependent on the ability to hold high electric fields in the bulk liquid, across the liquid surface, and in the gas. Careful design and construction of the electrodes used to establish these fields is therefore required. We present the design and production of the LUX-ZEPLIN (LZ) experiment’s high-voltage electrodes, a set of four woven mesh wire grids. Grid design drivers are discussed, with emphasis placed on design of the electron extraction region. We follow this with a description of the grid production process and a discussion of steps taken to validate the LZ grids prior to integration into the TPC.