Water Vapor Resistance Research Articles

Investigation of the Thermal Comfort Properties of Masks Used during the COVID-19 Pandemic.

SARS-CoV-2, the causative agent of COVID-19, which was officially declared a pandemic by the World Health Organization (WHO) on 11 March 2020, is transmitted from person to person through respiratory droplets and close contact and can cause severe respiratory failure and pneumonia. Currently, while the worldwide COVID-19 pandemic is still ongoing and countries are taking strict precautions to protect populations against infection, the most effective precautions still seem to be social distancing and wearing a mask. The question of how effective masks were in the early stages of the COVID-19 pandemic has been widely discussed, both in public and scientific circles, and the protection of different mask types has been examined. This study aimed to examine the comfort conditions provided by the different mask types to the user during use. For this purpose, single-ply, double-ply, three-ply, cloth, FFP1, FFP2, and FFP3 masks with different standards were examined, with and without a valve. To conduct the experiments, the novel thermal head measurement system, developed within the scope of this study, was used specifically for mask comfort studies. Thanks to the developed measurement system, the thermal resistance and water vapor resistance values of different masks were measured, and their comfort conditions were evaluated. According to the findings, cloth masks provide a comfortable condition, with lower thermal resistance and water vapor resistance values than other masks. In addition, it was observed that surgical masks offer better thermal comfort conditions, although they have lower protection than FFP masks.

Recent Trends in the Preparation of Nano-Starch Particles.

Starch is affected by several limitations, e.g., retro-gradation, high viscosity even at low concentrations, handling issues, poor freeze–thaw stability, low process tolerance, and gel opacity. In this context, physical, chemical, and enzymatic methods have been investigated for addressing such limitations or adding new attributes. Thus, the creation of biomaterial-based nanoparticles has sparked curiosity. Because of that, single nucleotide polymorphisms are gaining a lot of interest in food packaging technology. This is due to their ability to increase the mechanical and water vapor resistance of the matrix, as well as hide its re-crystallization during storage in high-humidity atmospheres and enhance the mechanical properties of films when binding in paper machines and paper coating. In medicine, single nucleotide polymorphisms (SNPs) are suitable as carriers in the field of drug delivery for immobilized bioactive or therapeutic agents, as well as wastewater treatments as an alternative to expensive activated carbons. Starch nanoparticle preparations can be performed by hydrolysis via acid hydrolysis of the amorphous part of a starch molecule, the use of enzymes such as pullulanase or isoamylase, or a combination of two regeneration and mechanical treatments with the employment of extrusion, irradiation, ultrasound, or precipitation. The possibility of obtaining cheap and easy-to-use methods for starch and starch derivative nanoparticles is of fundamental importance. Nano-precipitation and ultra-sonication are rather simple and reliable methods for nanoparticle production. The process involves the addition of a diluted starch solution into a non-solvent, and ultra-sonication aims to reduce the size by breaking the covalent bonds in polymeric material due to intense shear forces or mechanical effects associated with the collapsing of micro-bubbles by sound waves. The current study focuses on starch nanoparticle manufacturing, characterization, and emerging applications.

Thermal Protective Properties and Breathability of Multilayer Protective Woven Fabrics for Wildland Firefighting

A firefighter in the wildland fields spends an average of 8 to 16 h during which he encounters enormous physical effort and very demanding outdoor conditions of high temperatures. Research shows that the most common injuries are due to the occurrence of heat stress, and not due to lack of protection against burns. Therefore, for this very specific field of firefighting, it is necessary to provide clothing that will, in addition to adequate flame protection, provide good comfort properties such as lightweight suits, good porosity and breathability, so that gaseous sweat and heat generated by body heating can be released into the environment. The aim of this study was to determine the influence of structural parameters of multi-weft woven fabrics on two mutually contradictory properties—breathability and thermal protection. When designing fabrics, the goal was to produce a structure with a high proportion of volume pores, which, regardless of the increased volume of the fabric, insure the fabric mass would be acceptably small. Volume pores in the fabric have two roles—as a heat insulator and as an inhibitor of the breathability of the material. The analysis of the obtained results showed that the thickness and mass of the fabric have a greater influence on the water vapor resistance, while the heat transmission property is more affected by the thickness, porosity and fiber content.

Investigation on improvement of thermal, mechanical, and barrier properties of lignin/poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) using inorganic nanoparticles as fillers

AbstractIn this study, four typical biocomposites from lignin blended with poly‐3‐hydroxybutyrate‐3‐hydroxyhexanoate (PHBH) using inorganic nanoparticles (INPs) (SiO2, MMT, CaCO3, and BN) as fillers were evaluated, which enhanced the thermal, mechanical, and barrier properties of composites. The results revealed that the selection of suitable INPs doped into the lignin/PHBH (L/P) composites was an important approach to achieve available function. MMT/L/P nanocomposites were significantly higher than those of untreated L/P composites in thermal stability (Tmax exceed 10%) and barrier properties (water vapor and oxygen resistance increased by 48% and 46%), and BN particles increased the initial thermal decomposition temperature by 8%. The elongation at break of CaCO3/L/P and BN/L/P composites were increased by 344% and 319%, while SiO2/L/P composites had the best tensile strength (18.8 MPa). Besides, the INPs/L/P nanocomposites in this paper exhibited excellent ultraviolet (UV) resistance and might become potential anti‐UV packaging materials for grease foods.

Evaluation of Biophysical Properties of Potential Materials for the Manufacture of Protective Garments for Preterm Infants

Preterm infants, due to immature and dysfunctional skin, have increased water loss through the skin and consequently a decreased body temperature. In order to develop protective garments for preterm infants, it is important to select materials that will protect the child against water and heat loss. The authors are currently involved in the development of protective garments for premature babies, which are similar to baby clothes and contain a membrane that is partially permeable for vapor in combination with textile materials. This article presents the study of materials intended for the production of protective garments for pre-term infants. Samples of materials were investigated to determine biophysical comfort (tests of heat resistance, vapor resistance according to PN-EN ISO 11092:2014-11 and air permeability according to PN-EN ISO 9237) and porosity, surface mass in accordance with PN-EN 12127, and thickness in accordance with PN-EN ISO 5084. In order to determine the porosity of materials and to visualize the structure, tests on computer microtomography were carried out. The mechanical properties of the tested materials and the evaluation of the total hand value were characterized; the samples were tested on the KES device. The aim of this study was to select the most suitable fabrics for protective garments for premature infants to prevent excessive heat and moisture loss from the body, which can lead to hypothermia. For laminates, the optimal results of vapor resistance and heat resistance were obtained for laminate (15 g·m−2 PE foil + 15 g·m−2 PP non-woven), with a level of thermal resistance of 0.0766 m2·K·W−1 and vapor resistance of 188.729 m2·Pa·W−1, and for laminate (15 g·m−2 PE foil + 10 g·m−2 PP non-woven), with a level of thermal resistance of 0.0683 m2·K·W−1 and vapor resistance of 164.085 m2·Pa·W−1. For knitted fabrics, knitwear single cotton 155 g·m−2 showed the highest thermal resistance (0.0296 m2·K·W−1), and knitwear interlock polyester 120 g·m−2 showed the lowest thermal resistance (0.0179 m2·K·W−1). Knitwear cotton 120 g·m−2 had the highest water vapor resistance (8.402 m2·Pa·W−1), while knitwear interlock polyester 130 g·m−2 sample had the lowest resistance (6.356 m2·Pa·W−1). Garments for premature babies should have moisture barrier properties and high thermal insulation. They should also be characterized by optimal air permeability properties. Sample two-layer laminate (15 g·m−2 PE foil + 15 g·m−2 PP non-woven) had the best vapor resistance and thermal insulation properties. Moreover, this sample was characterized by good air permeability and surface weight compared to the other laminate samples. During the design of garments for premature babies, it is important to reduce the surface weight to as low as possible. Among the knitted fabrics, a knitwear single cotton 120 g·m−2 knitwear polyester interlock 120 g·m−2 was selected for having the best THV or tactile comfort. In addition, these knits were chosen for their lower surface weight. Based on the conducted tests, two-layer laminate (15 g·m−2 PE foil + 15 g·m−2 PP non-woven), the knitwear single cotton 120 g·m−2, and knitwear polyester interlock 120 g·m−2 were selected for further research.

Durability of metallic coating for improvement of thermal protective performance of firefighter protective clothing

The objective of this study is to investigate the durability of metallic coating for firefighter protective clothing when subjected to different washing cycles. Firefighter clothing ensemble consists of three layers, i.e. outer shell, moisture barrier, and thermal liner. The exposed surface of the outer shell was coated with silver particles through the physical vapor deposition process also called Magnetron sputtering. Afterwards, these specimens were exposed to radiant heat transmission machine at 30 kW/m2 and 40 kW/m2, respectively. It was found that specimens coated with silver particles showed improved thermal protective performance as compared to uncoated specimens. Later on, silver-coated specimens undergo five cycles of washing and their thermal protective performance in terms of transmitted heat flux density Qc (kW/m2) and radiant heat transmission index (RHTI 24 and RHTI 12) was measured. It was found that after five washing cycles, there was a negligible decline in thermal protective performance when exposed to 40 kW/m2. Afterwards, bending moment and water vapor resistance properties were measured before and after five washing cycles. It was inferred that there was no considerable difference in bending moment and water vapor resistance after different washing cycles, which confirmed stability of silver coating layers. However, when silver-coated outer shells were evaluated for abrasion resistance, there was a substantial decline in thermal protective performance on exposure to 40 kW/m2 after one hundred to five hundred cycles of abrasion.

Physical and Enzymatic Hydrolysis Modifications of Potato Starch Granules.

In this work, a valorization of the starch stemming from downgraded potatoes was approached through the preparation of starch nanoparticles using different physical methods, namely liquid and supercritical carbon dioxide, high energy ball milling (HEBM), and ultrasonication on the one hand and enzymatic hydrolysis on the other hand. Starch nanoparticles are beneficial as a reinforcement in food packaging technology as they enhance the mechanical and water vapor resistance of polymers. Also, starch nanoparticles are appropriate for medical applications as carriers for the delivery of bioactive or therapeutic agents. The obtained materials were characterized using X-ray diffraction as well as scanning and transmission electron microscopies (SEM and TEM), whereas the hydrolysates were analyzed using size exclusion chromatography coupled with pulsed amperometric detection (SEC-PAD). The acquired results revealed that the physical modification methods led to moderate alterations of the potato starch granules’ size and crystallinity. However, enzymatic hydrolysis conducted using Pullulanase enzyme followed by nanoprecipitation of the hydrolysates allowed us to obtain very tiny starch nanoparticles sized between 20 and 50 nm, much smaller than the native starch granules, which have an average size of 10 μm. The effects of enzyme concentration, temperature, and reaction medium pH on the extent of hydrolysis in terms of the polymer carbohydrates’ fractions were investigated. The most promising results were obtained with a Pullulanase enzyme concentration of 160 npun/g of starch, at a temperature of 60 °C in a pH 4 phosphate buffer solution resulting in the production of hydrolysates containing starch polymers with low molecular weights corresponding mainly to P-10, P-5, and fractions with molecular weights lower than P-5 Pullulan standards.

Performance of smart vapor retarders under hot and humid summer conditions

Today, there are many variations in water vapor control membranes including smart vapor retarders (SVRs), that function as vapor barriers but whose water vapor resistance drops when the ambient relative humidity becomes high. In the first half of this study, the change in water vapor resistance against ambient relative humidity in both directions was measured using the wet-cup method for the four types of two-layer SVRs consisting of hydrophobic and hydrophilic membranes and one type of vapor retarder. All the SVRs showed high water vapor resistance under an ambient relative humidity of 60% or less and low resistance above 75%. Additionally, a clear directional dependence of the water vapor resistance was observed for all SVRs. In the latter half of the study, two sets of small-scale field tests were conducted for six types of membranes, including polyethylene foil, under hot and humid summer weather conditions in Japan. The relative humidity dependence and water vapor diffusion direction dependence indicated by the cup method were validated and confirmed. In addition, the water vapor resistance in the ambient relative humidity range of 70–75% obtained by the cup method was strongly related to the retention of dryness of the specimens in the field tests.

Improved water vapor resistance of environmental barrier coatings densified by aluminum infiltration

A dense environmental barrier coating (EBC) was designed via aluminum infiltration into open pores or cracks to eliminate premature coating failure induced by the rapid permeation of oxidants through these pores. The water vapor corrosion performance of the EBC with and without aluminum infiltration was investigated at 1350 °C for 300 h under flowing 50%H2O–50%O2 gas. The infiltrated coating exhibited decrease silicon loss by more than 80%, almost no phase decomposition, and no continuous thermally grown oxide (TGO), furthermore, TGO thickness at the crack-root decreased by ∼90%. The excellent resistance is primarily attributed to the channel pores being filled with aluminum, which eliminates the rapid permeation of oxidants. In addition, a continuous refractory ytterbium aluminum garnet (YbAG) layer was formed in situ on the EBC surface, this layer exhibited sufficient stability in steam, rendering the EBC less permeable to oxidants.

50/60 Hz Power Grid Noise as a Skin Contact Measure of Textile ECG Electrodes

The electrocardiogram (ECG) is one of the most commonly measured biosignals. In particular, textile electrodes allow for the measuring of long-term ECG without skin irritation or other discomforts for the patient. Such textile electrodes, however, usually suffer from insufficient or unreliable skin contact. Thus, developing textile electrodes is impeded by the often-complicated differentiation between signal artifacts due to moving and breathing and artifacts related to unreliable skin contact. Here, we suggest a simple method of using 50/60 Hz power grid noise to evaluate the skin contact of different textile electrodes in comparison with commercial glued electrodes. We use this method to show the drying of wetted skin under an embroidered electrode as well as sweating of the originally dry skin under a coated electrode with high water vapor resistance.

Robust Superamphiphobic Fabrics with Excellent Hot Liquid Repellency and Hot Water Vapor Resistance.

Superamphiphobic surfaces progress rapidly but suffer from the issues of low repellency to hot liquids, complicated and nonaqueous preparation methods, and low durability. Here, a simple waterborne approach is developed to fabricate robust superamphiphobic fabrics with excellent hot liquid repellency and hot water vapor resistance. First, a perfluorodecyl polysiloxane (FD-POS) aqueous suspension was prepared by hydrolytic cocondensation of (3-glycidyloxy propyl)trimethoxysilane and 1H,1H,2H,2H-perfluorodecyltriethoxysilane with SiO2 particles. Then, the superamphiphobic fabrics were fabricated by dipping polyester fabrics in the suspension, which were then cured. The fabrics show excellent superamphiphobicity owing to the combination of the hierarchical micro-/nanostructure and FD-POS with very low surface energy. The superamphiphobic fabrics feature excellent hot liquid repellency even for a large volume of 130.0 °C soybean oil and condensed small droplets from ∼90.0 °C water vapor. This is attributed to its high superamphiphobicity, excellent hot water vapor resistance, and outstanding thermal durability. In addition, the superamphiphobic fabrics exhibit high mechanical and chemical durability against washing, abrasion, and immersion in corrosive or organic liquids. Thus, hot liquid repellent superamphiphobic fabrics may find applications in various fields such as antiadhesion of various hot liquids and in efficiently preventing scalding.

Phase composition and property evolution of (Yb1−xHox)2Si2O7 solid solution as environmental/thermal barrier coating candidates

RE disilicates are good candidates as environmental/thermal barrier coating for SiCf/SiC composite in harsh gas turbine engines. We designed (Yb1−xHox)2Si2O7 solid solutions and studied mechanical properties, thermal properties, and water vapor resistance. Powders with different compositions were synthesized by pressureless sintering, and bulk samples were prepared by Spark Plasma Sintering (SPS). Polymorphic changes with temperature and composition of the solid solutions were examined. Through doping Ho into Yb2Si2O7, water vapor corrosion resistance is significantly promoted, and thermal expansion coefficient is maintained close to that of Si-based ceramics. Compared with host disilicates, thermal conductivity of solid solutions are decreased, and mechanical properties, including Vickers hardness and fracture toughness, are increased. A two-phase domain is found at (Yb1/2Ho1/2)2Si2O7, and the γ to δ phase transition of Ho2Si2O7 is observed during SPS. Among all samples, γ-(Yb1/3Ho2/3)2Si2O7 possesses superior high temperature stability, and excellent water vapor resistance, indicating its performance as environmental/thermal barrier coating.

Multilayer Nonwoven Inserts with Aerogel/PCMs for the Improvement of Thermophysiological Comfort in Protective Clothing against the Cold

This study aimed to assess the developed nonwoven inserts with aerogel/PCM (phase change material) microcapsules for use in protective clothing against cold in terms of properties related to thermophysiological comfort. These inserts were obtained by the thermal bonding of a multilayer system consisting of needled-punched nonwovens and silica aerogel particles and/or PCM microcapsules evenly distributed between them. The influence of aerogel and PCM microcapsules on the basic physical properties of inserts, their microstructure, air permeability, and water vapor resistance was investigated and analyzed. The thermal insulation properties of inserts were assessed based on thermal conductivity results. The inserts with PCMs were also tested for their ability to regulate the temperature in the undergarment microclimate using the differential scanning calorimeter (DSC) and the “skin model” device. The research showed that the use of aerogel allowed for reducing the thermal conductivity of the insert by approximately 13% compared to the insert without additives. The high values obtained of the melting and crystallization enthalpy of inserts with PCMs confirmed their high efficiency in the heat absorption and release. Thus, the use of aerogel and PCMs in protective clothing against cold seems to be an effective solution for improving its protective properties and actively adapting its thermal insulation to the changing temperature conditions and the activity level of employees.

Impact of ultraviolet radiation on thermal protective performance and comfort properties of firefighter protective clothing

In this study, the impact of ultraviolet radiation is studied on thermal protective performance and clothing comfort properties of firefighter protective clothing. Firefighter clothing assembly consists of the outer shell, moisture barrier and thermal barrier. In this research, two different outer shells were utilized. Outer shell O1 consists of inherently fire- retardant fibres mainly consisting of Conex (Nomex) and firefighter assembly having Conex as the outer shell was called specimen A. On the other hand, clothing arrangement which employed Proban coated outer layer (O2) was termed as specimen B. Both specimens were evaluated for tensile testing, air permeability, radiant heat transmission machine, bending moment and water vapour resistance before and after exposure to ultraviolet radiation. The tensile strength value of outer shell O2 was higher than that of O1 before and after exposure to UV radiation. Tensile strength values of both outer shells O1 and O2 decline after exposure to ultraviolet radiation. Air permeability values of both outer shell O1 and O2 increase after being exposed to ultraviolet radiation. It was noted that specimen A has better thermal protective performance as compared to specimen B, before and after exposure to UV radiation. Also, radiant heat transmission index RHTI 24 values were greater for specimen A as compared to specimen B, before and after exposure to UV radiation. Moreover, bending moment values for both outer shell O1 and O2 decline after being subjected to UV radiation. Furthermore, Water vapour resistance values of outer shell O1 and outer shell O2 enhance after exposure to ultraviolet radiation.

Thermophysiological properties of bovine leather in dependence on the sampling point, tanning and finishing agents

The influence of differently tanned and finished bovine leather on thermophysiological properties was investigated. In addition, it was investigated whether sampling has a significant influence on the thermophysiological properties. The back of the tested leathers is thicker than the neck because of better microstructure regularity and uniformity as well as thicker and denser distributed fibrils than in the neck parts. The neck parts have a greater proportion of air-filled spaces between the fibrils, resulting in a higher thermal resistance of the leather neck parts. Considering the thickness of synthetic and chrome-tanned leathers (dyed and hydrophobized), the thinner chrome-tanned leathers (0.063 W m−1 °C−1 for the neck part, 0.090 W m−1 °C−1 for the back part part) have almost the same thermal conductivity as synthetic ones (0.065 W m−1 °C−1 for the neck part, 0.089 W m−1 °C−1 for the back part). Their thermal and water vapour resistance show considerable differences. There is no significant difference in water vapour resistance of the neck and back part of chrome tanned, dyed and hydrophobized leather (25.27 m2 Pa W−1 for the neck part; 25.15 m2 Pa W−1 for the back part) in contrast to equally treated synthetically tanned leather (30.38 m2 Pa W−1 for the neck part; 26.96 m2 Pa W−1 for the back part).The presented study could help in choosing the appropriate point of sampling, tanning as well as finishing agents for obtaining satisfying thermophysiological comfort in the wide range of leather application.

INFLUENCE OF ANTISTATIC POLYESTER FIBERS ON THE PROPERTIES OF COTTON AND POLYESTER SINGLE JERSEY KNITTED FABRICS

In this research, the influence of the antistatic polyester fibers containing carbon black on the comfort properties of 100% and blended cotton as well as on 100% and blended polyester single jersey knitted fabrics was evaluated. The research results revealed that the behavior of the investigated knitted fabrics was dependent on their structure and mechanical characteristics. The electrical resistance of knitted fabrics decreased significantly due to the use of 4% antistatic polyester fibers. The electrical resistance of the pure and blended cotton knitted fabric was lower than that of the pure and blended polyester knitted fabrics. Antistatic polyester fibers positively influenced the air permeability of the polyester knitted fabric. The air permeability of 100% and blended cotton fabrics was approximately 3.5 times compared to both 100% and blended polyester fabrics, respectively. The carbon black polyester fibers influenced the decrease in thermal resistance, the increase in vapor permeability, and the minor increase in vapor resistance of both cotton and polyester knitted fabrics. Thermal resistance was lower, water vapor resistance was significantly higher, and relative water vapor permeability was slightly lower for the cotton and cotton/antistatic polyester knitted fabrics than for the polyester and polyester / antistatic polyester knitted fabrics, respectively. Therefore, the research results revealed that the presence of 4% antistatic polyester fibers in cotton and polyester knitted fabrics positively influenced their antistatic behavior and improved or almost did not alter their comfort properties.

Assessment of the Impact of the Surface Modification Processes of Cotton and Polyester Fabrics with Various Techniques on Their Structural, Biophysical, Sensory, and Mechanical Properties.

This article presents research on the assessment of the impact of surface modification of cotton and polyester fabrics using four techniques (flocking, layer by layer, screen printing and thermal-transfer printing) on their structural, mechanical, biophysical, and sensory properties. Depending on geometry and raw materials of the fabrics, the clothing made of them it is characterized by certain biophysical properties which are intended to protect the human body against external factors, but also against excessive sweating and overheating or cooling down. The aforementioned properties of the modified textiles were determined with: optical microscopy, microcomputed tomography, a tensile testing machine, sweating guarded-hotplate, air permeability tester, and the Kawabata evaluation system. Based on analysis of obtained results, it can be concluded that flocking reduces air permeability the most (−77% for cotton fabric and −99.7% for polyester fabric), and total hand value (−58% and −57%) and increases water vapor resistance the most (+769% and +612%) while the screen printing increases the thermal resistance the most (+119% and +156%) compared to unmodified textiles. It can be concluded that, when modifying textile substrates, the area of modification and their size on clothing products should be carefully selected so as not to adversely affect the feelings of potential wearers.

Degradation, migration, and removal of trichlorfon on harvested apples during storage at room temperature

Dissipation of an organophosphorus pesticide, trichlorfon, in natural and waxed apples during storage was studied. The results showed that the trichlorfon content in natural and waxed apples decreased by 85% and 64%, respectively, during storage. The morphology of the surface film was dense and regular, which resulted in a higher water vapor resistance and a lower respiration rate in the waxed apples. This indicates that waxing affected the dissipation of pesticide residues in the apple storage environment, increasing food safety risk. Ozone was used to remove the residual pesticides on the apple surface. The trichlorfon degradation rate reached 73%. The ozone treatment had no effect on the surface color of the apple, which means that the fruit can be pre-treated with ozone prior to waxing or storage.

Moisture barrier layer with supplemental chemical and biological protective functionality for firefighting clothing applications

One of the primary constituent layers of fire protective clothing is a flame-retardant, waterproof and breathable moisture barrier, which permits the outward transfer of perspiration from the firefighter’s body, while barring the inward entry of water. The introduction of a chemical and biological resistant functionality can greatly enhance the overall applicability of fire protective clothing. In the present work, a chemical & biological resistant waterproof breathable flame retardant moisture barrier fabric was prepared by laminating a biaxially stretched microporous expanded polytetraflouroethylene (ePTFE) membrane with Activated Carbon Fabric using a hot melt reactive breathable polyurethane adhesive. The developed laminate was found to exhibit an excellent balance of waterproofness (23 kPa) and breathability, which was quantified in terms of water vapour transmission rate (WVTR) and water vapour resistance (Ret). High values of WVTR, 1.1025 × 104 ± 9.8×101 g/m2/day complimented with exceptionally low values of Ret, 2.9 m2Pa/W are indicative of its high degree of breathability. Vertical flammability tests clearly revealed the exceptional flame resistance offered by the laminate, where after-flame, after-glow or melt-dripping was not observed and the char length was ∼4.2 cm. Further, the laminate exhibited requisite degree of protection against biological and chemical warfare (CW) agent with no breakthrough of the CW agent being perceived within the time frame of 24 h. The excellent combination of flame retardancy, breathability, waterproofness, chemical and biological protection, bestows the laminate excellent potential for usage as moisture barrier in fire protective clothing applications.

Thermo-physiological comfort properties of different woven fabrics used in sportswear for outdoor activities

In this study, the thermo-physiological wear comfort is mainly characterized by the thermal and water vapor resistance performance of the woven fabrics used as sportswear for outdoor activities. The commonly used twill woven fabric with different thicknesses, weight, and density are selected for the experimental analysis, and it finds that fabric weight and thickness have crucial effects on the thermal resistance, and the water vapor resistance depends linearly on density and thickness. The present study gives an optimal design of sportswear for outdoor activities with low thermal and water vapor resistance.