Barrier Fabrics Research Articles

Recycling of cotton apparel waste and its utilization as a thermal insulation layer in high performance clothing

Recycling and converting textile waste into value-added products with enhanced functional properties pave the way toward a circular economy for sustainability. This research investigates the utilization of recycled cotton fiber from apparel cutting waste for fabricating high-performance thermal barrier fabrics. The physical characterization of the developed fabrics revealed a regular arrangement of fibers, consequently the uniform thickness of the fabric with no distortion on fiber surfaces due to the recycling operation of cotton waste. The developed fabrics also demonstrated a high softness index and low compression and bending average rigidity compared to the commercial fabric with similar thickness. The heat protection performance revealed an increase in fabric conductive and radiative heat resistance with increasing the amount of recycled cotton fiber in the fabrics. The inherent thermal resistance of cotton fiber and the low inter-fiber spacing because of their uniform orientation in the fabric lead to the high thermal resistance of developed fabrics. In the case of fabric air permeability concerning the clothing thermal comfort, no significant difference in breathability was observed among the test specimens. Besides, the moisture management profile of developed fabrics indicated the capability to create favorable thermal comfort within the clothing-skin microenvironment because of improved liquid transportation and diffusion of perspiration vapor through the fabric.

A new thermal protective clothing design with silica aerogel filled acrylic nanofibers

PurposeFirefighters are exposed to high outdoor temperature and heat stress caused by metabolic activities during firefighting and should wear protective clothing to ensure their safety and health. Traditional firefighter protective suits are bulky and heavy garments with reduced thermal comfort properties since the fabric thickness and moisture barrier layers prevent heat transfer of the garment and cause additional heat stress. The aim of this study is to reduce heat stress by creating a new fabric design with silica aerogel membrane as a moisture barrier for three-layer fabric system.Design/methodology/approachPolyacrylonitrile (PAN) nanofibers were produced with three different silica aerogel contents and used for three-layered clothing system as a moisture barrier for giving desired protectiveness and thermal comfort to firefighters. Different fabric combinations were designed using two types of outer shell fabrics, two types of moisture barrier fabrics, two types of thermal barrier fabrics and PAN/silica aerogel membranes.FindingsThe results show that a lighter fabric system with improved wearer’s mobility and thermal comfort properties (thermal resistance and moisture permeability) is achieved with the use of PAN/silica aerogel membrane as an intermediate layer compared to commercial thermal protective fabric systems.Originality/valueDifferently from traditional thermal protective clothing, which may not provide adequate protection in long-term heat conditions or when exposed to flash fire, a new thermal protective clothing has been developed to be used in extremely hot environments, providing desired technical and performance properties, ease to wear comfort.

Ascorbic Acid as an Adjuvant to Unbleached Cotton Promotes Antimicrobial Activity in Spunlace Nonwovens.

The development of affordable, effective, and environmentally friendly barrier fabrics is a current goal in antimicrobial textile development. The discovery of new routes to achieve non-toxic naturally occurring molecules with antimicrobial activity is of interest in the development of materials that promote wound healing, improve hygiene, and offer protection against nosocomial infection. Highly cleaned and sterile unbleached cotton has constituents that produce hydrogen peroxide at levels commensurate with those that favor cell signaling in wound healing. Here, we show the antimicrobial and antiviral properties of spunlaced griege cotton-containing nonwovens treated with ascorbic acid formulations. The mechanism of action occurs through the promotion of enhanced hydrogen peroxide activity. The levels of hydrogen peroxide activity afford antimicrobial activity against Gram-negative and Gram-positive bacteria and antiviral activity against MS2 bacteriophages. Spun-bond nonwoven unbleached cotton was treated with ascorbic acid using traditional pad-dry-cure methods. An assessment of antibacterial and antiviral activity against Staphylococcus aureus, Klebsiella pneumoniae, and MS2 bacteriophages with the AATCC 100 test method showed a 99.99% inhibitory activity. An approach to the covalent attachment of ascorbic to cellulose through citric acid crosslinking chemistry is also discussed. Thus, a simple, low-cost approach to antimicrobial and antiviral cotton-based nonwovens applicable to dressings, nosocomial barrier fabrics, and face masks can be adopted by combining ascorbic acid with spunlace greige cotton nonwoven fabrics.

Ultrathin fluoroacrylic coating wrapped microporous non-woven fabrics as efficient air filtration membranes.

Ultrathin fluoroacrylic emulsion coating wrapped effective microporous non-woven air filtration membranes of 0.2 μm thickness were made for PPE masks with up to 99.9% filtration efficiencies for both 0.3 μm NaCl aerosol particles and oily DEHS aerosols. An ultrasonic dip-coating process was applied for the controllable formation of a nano-protrusion morphology on the fiber surface.

Effect of Fabric Layers on Thermal Comfort Properties of Multilayered Thermal Protective Fabrics

Abstract Thermal protective clothings are produced from multilayered textile materials. Fabric layers need to allow enough evaporation of perspiration, ventilation, and also thermal protection from fire. This study aimed to evaluate the effects of different fabric layers and their different combinations on the thermal properties of multilayered fabric samples. Three-layered fabric combinations were created using two types of outer shell fabrics, four types of moisture barrier fabrics with membrane, and two types of thermal barrier fabrics. Sixteen different fabric combinations that simulate three-layered thermal protective clothing were studied. As a result of the study, it was found that thermal and moisture comfort properties were significantly affected by different fabric layers.

Assessing fire-blocking effectiveness of barrier fabrics in the cone calorimeter

Cone calorimetry experiments of on flexible polyurethane foam and flexible polyurethane foam covered with a variety of fire-blocking barrier fabrics were used to characterize and rank the effectiveness of barrier fabrics with the ultimate goal being an ability to predict the effectiveness of barrier fabrics for reducing the flammability of residential upholstered furniture. The primary measure used to characterize the burning behavior was heat release rate. The effect of the underlying sample substrate was shown to have a large effect on the burning behavior of flexible polyurethane foam samples, and a thermally insulating substrate was used during composite experiments. At times, rapid heat release rate fluctuations were observed, and in such cases approximate corrections were applied to correct for finite cone calorimeter time response. Measurements using thermocouples placed within the flexible polyurethane foam provided insights on flexible polyurethane foam pyrolysis behavior, the collapse rate of flexible polyurethane foam, and the thermal protective properties of barrier materials. Heat release rate temporal profiles for flexible polyurethane foam showed two distinct burning stages with peak values which have been attributed to sequential burning of species (primarily) derived from the diamine ( PHRR1) and polyol components ( PHRR2) used to manufacture the flexible polyurethane foam. When a barrier fabric was added, many of the composites displayed a three-stage burning behavior which was attributed to an initial short, intense burning (termed flash burning) stage associated with the barrier fabric covering followed by the two flexible polyurethane foam stages. Seven out of 16 flexible polyurethane foam/barrier fabric composites exhibited flame extinction prior to fuel burn out. Five out of the seven composites reignited when the spark ignition source was reapplied. Reignition allowed barrier fabric effectiveness to be assessed even for cases with flame extinction. Barrier fabric performance was shown to be consistent with four properties that were previously identified as important barrier fabric properties: barrier fabric flammability, gas permeability, thermal protection, and physical integrity. In addition, the current experiments indicate the presence and effectiveness of gas-phase active flame retardants in the barrier fabric can also play an important role. A limited number of tests were conducted to de-couple the effects of flame-retardant chemicals and physical effects of barrier fabrics on flexible polyurethane foam burning behavior. These tests showed that while flame-retardant chemicals can be effective in quenching and extinguishing the flames, the presence of effective barrier fabric shells is also very important in lowering the heat release rate of burning flexible polyurethane foam. In general, the presence of a barrier fabric was shown to reduce the heat release rate peak values during both flexible polyurethane foam burning stages. The magnitude of the peak associated with second-stage flexible polyurethane foam burning was deemed the most appropriate for characterizing the thermal protection provided by a barrier fabric. Since the times for PHRR2also varied between composites, a measurement referred to as the peak fire growth rate (PFIGRA) parameter was calculated by dividing the heat release rate by time since time to ignition and PFIGRA2was also considered for characterizing the barrier fabrics. Three possible classification schemes, each consisting of three classes, were introduced based on composite flame extinction and reignition behavior, PHRR2values, and PFIGRA2values. Each scheme provided differentiation between barrier fabric effectiveness. While the schemes were able to assess whether the barrier fabrics were particularly effective or ineffective, there were variations among classes of barrier fabrics having intermediate levels of effectiveness. Further work will be required to assess which, if any, of the classification schemes are most appropriate for predicting barrier fabric performance in residential upholstered furniture.

Medical Textiles: Application of Implantable Medical Textiles

The use of textiles in the medical sector is increasing day by day. An important and emerging part of the textile industry is medical, hygiene and health care sector. Textiles are a compelling solution for implantable medical devices, primarily due to the versatility they offer in product design. Textiles are in 2D and 3D implantable forms, with configurations limited only by the imagination. The number of applications is enormous and diverse, ranging from a single thread suture to the complex composite structures for bone replacement and from the simple cleaning wipe to advanced barrier fabrics used in Operation Theater. The main object of this work is to study the types of implantable textiles used in the medical sector such as surgical suture, artificial skin, artificial ligament, and artificial cartilage. In this study, we have included different types of raw materials used and the manufacturing process of these implantable medical textiles.

Morphometrical structural analysis of inter-thread pores in woven fabrics with the use of computer image analysis

The main aim of the study is to present a new innovative method designed by the author of non-destructive, accurate and morphometrical identification of fabric structural parameters, individual inter-thread pores (ITPs) in particular. The description parameters and fabric structure assessment methodology with the use of digital image analysis with author's copyrighted MagFABRIC software were created specifically for this analysis. The ITP parameters were described in three aspects: size, shape and location in the fabric structure. The study was conducted on two groups of fabrics: plain and twill weave. The need for a bimodal analysis of the fabric structure parameters was indicated, as it allowed for the structure differences identification in the test fabrics. The analysis results were compared to the air permeability test. The developed methodology is relevant to specialized fabrics (e.g. barrier fabrics, industrial filters and any other fabric where the ITP area is an important parameter).

Thermal comfort properties of firefighters’ clothing with underwear

Optimal comfort will enable the wearer to work efficiently over long periods of time and help to protect the body from imminent overheating. The thermal performance of fire fighters’ protective clothing is primarily based on the thermophysical properties of the materials that are used to construct the clothing. In this study, we have used new fire resistant underwear. The main purpose of this study is to evaluate the single fabric layer thermal comfort behaviours of underwear, outer shell, moisture barrier and thermal barrier fabrics together with their three-layered and four-layered combinations to understand their multilayer fabric thermal comfort performances.

Numerical micro-scale modelling of the mechanical loading of woven fabrics equipped with particles

The equipping of polyester multifilament fabrics with functionalized micro particles for partial and targeted reduction of the size of continuous inter-yarn pores in the fabric, utilizing the filtering effect of textile surfaces, has proven to be a very effective method for increasing the barrier properties of fabrics for use as surgical reusable textiles, cleanroom clothing or cleanable filter media. The objectives of this study were to understand the interrelationships of weaving parameters and fabric properties and to model the porous fabrics under loading conditions. Artificial Neural Networks were trained and tested in order to link the weaving and processing parameters with the fabric properties using the experimental data. Mean flow pore sizes and permeability values of woven fabrics under biaxial loading conditions were measured according to a method previously developed using a special sample holder connected to a conventional porosimetry. Finite element models of unit cells were developed and loaded virtually. Those models were transferred into voxel models and imported into software DNSlab, where they were virtually equipped with particles. For the simulation of the fluid flow, the Navier-Stokes equations were solved numerically by the Lattice-Boltzmann method. The experimental and numerical studies show that pore size of barrier fabrics can be tailored using the developed methods and models. Important parameters are the fabric construction parameters and the particle size.

New Image Analysis Method for Determination of the Inter-Fibre Pore Size Intensity of Polyester Woven Barrier Fabrics

Porosity is an important characteristic of a filter textile, which affects permeability and retention properties. Determination of the inter-yarn and inter-fibre pore sizes of barrier textiles is also required to assess the filter behaviour of these textiles. In this study, a software tool was developed to detect the inter-fibre pore size distribution and pore size intensity of multifilament woven barrier fabrics using cross-section images. Fabrics were chosen according to their fabric construction parameters, such as the fabric index, weft yarn filament fineness and weft yarn structure (flat or textured). Microscopic cross-section images of weft yarns were taken, processed to binary images, and analysed with respect to the pore size distribution, number of pore lengths and pore intensity. It was also analysed how the fabric index, filament cross-section and filament fineness affect the inter-fibre pore lengths and separation level proposed. It was found that weft yarns with wider lengths and lower height showed wider inter-fibre pores. Inter-fibre pores decreased with a decrease in filament fineness. Moreover the separation level proposed deviated from the 90% level depending on the fabric index. This deviation was very small in samples with reduced filament fineness and textured samples. The separation level proposed will be useful to understand the effect of fabric construction parameters to obtain targeted properties regarding inter-fibre and inter-yarn pore size.

New Method for In-situ Measurement of Pore Size Deformation of Barrier Textiles under Biaxial Loading

The pore size is one of the vital morphological characteristics of barrier fabrics as it decisively affects their permeability and retention properties. Apart from fabric construction and material aspects, the pore size also depends on applied mechanical loads, which occur during typical usage life cycles. Among others, barrier fabrics such as surgical gowns are exposed to loads during their use. These loads have a significant effect on the fabric morphology which influences the permeability properties as well. In this study, a newly developed in situ pore size measurement method was used to measure the changes in pore size that occur in high density barrier woven fabrics under biaxial loadings and after cyclic loading. It was observed that, under tension, pore size distributions changed and mean flow pore sizes increased. Results revealed that the developed in situ measurement method has a great potential for the determination of pore size changes in barrier textiles under biaxial loading.

Prediction of yarn crimp in PES multifilament woven barrier fabrics using artificial neural network

This research was aimed to develop artificial neural network (ANN) models to predict yarn crimp in woven barrier fabrics. For ANN training, 52 polyester (PES) multifilament barrier fabrics were produced by varying weft yarn and filament fineness, yarn type, weft density, weave type, and loom parameters. The supervised training of neural network was performed using Matlab® ANN toolbox function ‘trainbr’ which is the incorporation of Levenberg-Marquardt (LM) optimization and automated Bayesian regularization into backpropagation. From modeling outcomes, it was observed that both warp and weft yarn crimp models have generalized well with excellent coefficient of determination and trivial mean absolute error when tested on novel data. Moreover, input rank analysis of optimized network provided important information about model stability with respect to input variables, and trend analysis elucidated the input-crimp behavior using different input levels.

Analysis and prediction of air permeability of woven barrier fabrics with respect to material, fabric construction and process parameters

Air permeability is one of the important properties of conventional as well as technical fabrics such as protective garments, filters, and fabrics for airbags and parachutes. In case of surgical textiles, air permeability is an effective measure of thermo-physiological comfort. This study is aimed to analyze PES barrier fabrics and to develop correlation between permeability and influential material, construction and process parameters. Not only the individual effects of yarn, fabric and loom parameters but also the underlying complex interactions between fewer or several of these influencing factors exert significant influence on fabric porosity and permeability. Artificial neural network (ANN) is the suitable tool to map such complex input-output relationships, since a direct analytical solution is not possible. Feedforward neural network models were trained with combination of Levenberg-Marquardt algorithm and Bayesian regularization support incorporated in backpropagation. Based on the number of input variables, three ANN models were optimized. It was observed that the model which was trained with all selected inputs delivered promising results on test data, i.e., R2=0.985 and mean absolute error of 1.8%. To eliminate any doubt of overfitting, 10 % cross-validation was also performed for selected final model. Furthermore, to investigate the relative importance of input variables in the optimized ANN model, the rank analysis was also carried out. Research outcomes reveal that ANN can be used to tailor barrier fabric permeability depending on the requirements quickly without trials and error by adjusting loom, fabric and yarn parameters.

The role of barrier function of mucous membranes in allergic diseases and sublingual allergen-specific immunotherapy

Currently one of the factors of allergy predisposition is the increase in barrier permeability of the mucous membranes of the respiratory system and the gastrointestinal tract (GIT). It defines the probability of an emergence of an allergic response. To understand the mechanisms of the interaction of the mucous membranes of different systems that explain their common function is undoubtedly necessary for discussion of this problem. The features of microbiome influence and the changes of the microbiome state during the formation of the immune response to the contact with allergens are of particular interest. The structure of the epithelial barrier of the airwaysand GIT, and mechanisms of allergen transport through barrier systems with the subsequent interaction with the cells (?) associated with barrier fabrics have been considered. The possible role of the barrier function of mucous membranes in conducting sublingual allergen-specific immunotherapy (SLIT) is discussed.

Factors for Consideration in an Open-Flame Test for Assessing Fire Blocking Performance of Barrier Fabrics.

The main objective of the work reported here is to assess factors that could affect the outcome of a proposed open flame test for barrier fabrics (BF-open flame test). The BF-open flame test characterizes barrier effectiveness by monitoring the ignition of a flexible polyurethane foam (FPUF) layer placed in contact with the upper side of the barrier fabric, exposed to a burner flame from below. Particular attention is given to the factors that influence the ignitibility of the FPUF, including thermal resistance, permeability, and structural integrity of the barrier fabrics (BFs). A number of barrier fabrics, displaying a wide range of the properties, are tested with the BF-open flame test. Visual observations of the FPUF burning behavior and BF char patterns, in addition to heat flux measurements on the unexposed side of the barrier fabrics, are used to assess the protective performance of the BF specimen under the open flame test conditions. The temperature and heat transfer measurements on the unexposed side of the BF and subsequent ranking of BFs for their thermal protective performance suggest that the BF-open flame test does not differentiate barrier fabrics based on their heat transfer properties. A similar conclusion is reached with regard to BF permeability characterized at room temperature. However, the outcome of this BF-open flame test is found to be heavily influenced by the structural integrity of thermally degraded BF. The BF-open flame test, in its current form, only ignited FPUF when structural failure of the barrier was observed.

Morphology and pore size distribution of electrospun and centrifugal forcespun nylon 6 nanofiber membranes

The porosity and high surface-area-to-volume ratio of nanofiber membranes offer potential for diverse applications, including high-efficiency filters and barrier fabrics for use in protective textiles. The objective of this research is to examine the morphology and pore size distribution of nanofiber membranes prepared using two spinning methods, that is, electrospinning and forcespinning. The results indicate that fiber diameter is impacted by spinning solution viscosity in an analogous way for both spinning methods. Higher concentrations resulted in larger fiber diameters in both electrospun and forcespun membranes. Fiber diameter and membrane areal density were found to significantly impact membrane pore size distribution. A theoretical model was used to describe pore size variation and was found to agree with the empirical patterns in the case of electrospun membranes.

Clinical Issues—May 2015

This MonthUpdate on perioperative Ebola precautionsKey words: Ebola, PPE, airborne, droplet, respirator.Contaminated rigid sterilization containersKey words: rigid sterilization containers, filters, valves, latches, gaskets.Requirements for storing autologous tissueKey words: tissue bank, autologous tissue, US Food and Drug Administration, human cells, delayed replantation or autotransplantation.Storing autologous human vein autograftsKey words: autografts, storage media, Tiprotec®, X‐Vivo 10®, American Association of Tissue Banks.Dropped autograftsKey words: autograft, pulse lavage, wound classification, dropped grafts, cranial bone graft.Antimicrobial and fluid barrier fabricsKey words: antimicrobial fabrics, fluid barrier fabrics, surgical site infections, scrub attire, surgical attire.

An Analysis on the Moisture and Thermal Protective Performance of Firefighter Clothing Based on Different Layer Combinations and Effect of Washing on Heat Protection and Vapour Transfer Performance

Fabric assemblies for firefighting clothing have been tested for heat protection and comfort. The constituent materials and fabric structures have been specifically selected and tailored for firefighters’ clothing. In order to do this, four types of outer shell fabrics, four types of moisture barrier fabrics, and four types of heat barriers with different weights and material compositions were used to make a multilayered fabric assembly. Heat transfer (flame), heat transfer (radiant), and water vapour resistance tests were conducted according to the latest EN469 test standard which also recommends washing tests. These tests reveal that material content and material brand have considerable effect on the required performance levels of heat protection. In addition, while washing tests have improved water vapor transfer properties, they have a deteriorating effect on heat protection performance. Considering heat protection and moisture comfort properties, the optimal assemblies are thereby identified.

Targeted partial finishing of barrier textiles with microparticles, and their effects on barrier properties and comfort

Woven barrier fabrics for filtration and operating room textiles feature permeable pore channels between yarn interlocking points (mesopores), which create an increased risk of penetration by contaminated fluids and particles. These pore channels can be reduced in size by high-density weaving. This, however, results in deteriorated drapability and performance characteristics. To meet the requirements made on the barrier effect without impairing the physiological properties of the textile, fluid-tight and particle-tight woven fabrics with adjustable porosity are being developed. This research aim could be realized by the targeted and partial application of microparticles into the mesopores. There, they form a meshed structure in the pores, whose size is thus reduced without them being entirely obstructed. The simultaneous retention of the micropores (pores between the individual filaments) in the woven fabric guarantees preservation of the physiological characteristics of the textile. The efficiency of the finishing was examined by an extensive physiological and physical characterization of the woven fabrics before and after particle application. Regarding the test method used to monitor the barrier effect and the channel paths, a test device was modified to simulate the demands of later, practical use.