scholarly journals Influence of Fabric Weave on Thermal Radiation Resistance and Water Vapor Permeability

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 525
Author(s):  
Ana Kiš ◽  
Snježana Brnada ◽  
Stana Kovačević
Keyword(s):  
High Temperatures ◽  
High Performance ◽  
Thermal Protection ◽  
Water Vapor Permeability ◽  
Radiant Heat ◽  
The Body ◽  
Vapor Permeability ◽  
Weave Structure ◽  
Fabric Structures ◽  
The Impact

In this work, aramid fibers were used to develop new, high-performance fabrics for high-temperature protective clothing. The research was based on the impact of the weave structure on fabric resistance to radiant heat. The goals of the research were primarily related to the development of new fabric structures created by the weave structure, which gives better protection of the body against high temperatures in relation to the standard weave structures that are used today. According to the results obtained it can be concluded that the fabric weave significantly affects the fabric structure, which consequently determines the effectiveness of protection against high temperatures. The justification for the use of multi-weft and strucks weave structure, which provides greater thermal protection and satisfactory breathability than commonly used weave structures, was ascertained.

New Features of Silver/Zinc Loaded Nanocomposite Textiles; Dyeability, Abrasion Resistance and Comfort

2014 ◽  
Vol 9 (4) ◽  
pp. 155892501400900
Author(s):  
Roya Dastjerdi
Keyword(s):  
Abrasion Resistance ◽  
Melt Spinning ◽  
Water Vapor Permeability ◽  
The Body ◽  
Vapor Permeability ◽  
Close Relationship ◽  
Spinning Process ◽  
Multifilament Yarns ◽  
Body Heat ◽  
Positively Charged

This paper investigates the effect of nanoparticles on some new features of silver/zinc loaded nanocomposite fabrics. These fabrics have been fabricated from continuous nanocomposite multifilament yarns produced on a pilot plant melt spinning process with the take-up speed of 2000 m.min-1. According to the results, the dyeability of nanocomposite fabrics with acidic dyes increased as compared to the pure PP. The electrostatic interaction between negatively charged group of acidic dye molecules and positively charged silver nanoparticles can improve dyeability. The results indicated close relationship between the abrasion resistance of fabrics and tensile properties of produced yarns including tenacity, modulus, and rupture work. The results also showed the increasing of the water vapor permeability at temperatures above 25 oC and decreasing permeability at temperatures below 25 oC for nanocomposite fabrics containing 0.1 wt% silver/zinc. This simplifies removing of body heat and sweat and consequently offers more comfort for garment, tent, curtain, etc. at temperatures above 25oC. On the other hand, lower vapor permeability at a low temperature protects the body from cool weather through preventing loss of the body heat and weather flow. This nanocomposite fabric can smartly adapt the permeability with human body requirements by changing the environment temperatures.

scholarly journals Thermo-physiological Comfort Properties of Polyester and Polyester/Acrylic blended Synthetic Fabrics treated with Herbal Finishes

2014 ◽  
Vol 9 (3) ◽  
pp. 155892501400900
Author(s):  
Gunasekaran Govindachetty ◽  
Periyasamy Sidhan ◽  
Koushik C. Venkatraman
Keyword(s):  
Thermal Conductivity ◽  
Water Vapor Permeability ◽  
The Body ◽  
Bermuda Grass ◽  
Vapor Permeability ◽  
Moisture Management ◽  
Hydrophobic Nature ◽  
Medicinal Properties ◽  
Moisture Vapor ◽  
Natural Fabrics

Thermo-physiological comfort in clothing mainly lies in moisture management, which often refers to the transport of both moisture vapor and liquid away from the body. Moisture management of fabrics is chiefly influenced by the thermal properties of those fabrics. In spite of the convincing properties that synthetic fabrics have, they are not much preferred because of their hydrophobic nature which provides less comfort to the wearer compared to the natural fabrics like cotton, wool, and silk. Previous studies report that the herbal finishes, which are eco-friendly in nature, improve the anti-microbial and other medicinal properties but very little or no work has been carried out on the comfort aspect of these fabrics. This work reports a study of the influence of two ecofriendly herbal finishes, Neem and Bermuda grass, on the thermo-physiological comfort properties of synthetic fabrics used in clothing. The herbal finishes were applied on to 100% Polyester and 50/50 Polyester/Acrylic blended fabrics. Prior to the application of finishes, the fabrics were given a pretreatment to achieve a better penetration and durability of the finishes. The finished fabrics were tested for the thermo-physiological comfort properties of Wicking, Water vapor permeability, and Thermal conductivity and the results were analyzed. It was revealed that both the Neem and Bermuda grass natural finishes considerably improved the moisture related properties and moderately reduced the thermal conductivity characteristics of the above synthetic fabrics. Durability to washing was also tested and discussed.

scholarly journals Active Biodegradable Polyvinyl Alcohol–Hemicellulose/Tea Polyphenol Films with Excellent Moisture Resistance Prepared via Ultrasound Assistance for Food Packaging

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 219
Author(s):  
Yining Wang ◽  
Jinhui Li ◽  
Xin Guo ◽  
Haisong Wang ◽  
Fang Qian ◽  
...  
Keyword(s):  
Water Vapor ◽  
High Performance ◽  
Food Packaging ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Poly Vinyl Alcohol ◽  
Vapor Permeability ◽  
Moisture Resistance ◽  
Film Material ◽  
Strength Performance

Poor water-vapor barriers and mechanical properties are common problems of biobased films. To maintain food quality, the barrier and its strength performance need to be improved. Tea polyphenols (TP) are a natural active substance, and their benzene ring structure provides a barrier for them as a film material. Films that incorporate TP also have enriched functionalities, e.g., as antioxidants. Here, active poly (vinyl alcohol) (PVA)-hemicellulose (HC)/TP films with good moisture resistance and antioxidant capacity were prepared via ultrasound assistance. The effects of TP incorporation and ultrasonication on the physical, antioxidant, and micromorphological properties of the films were investigated. Results showed that the addition of TP improved the thermal stability and water-vapor permeability (WVP) of the composite films. When a PVA-HC/TP composite film with a PVA-HC to TP mass ratio of 100:10 was treated with ultrasonication for 45 min, tensile strength was 25.61 Mpa, which was increased by 54% from the film without any treatment, and water-vapor permeability (WVP) value declined from 49% to 4.29 × 10−12 g·cm/cm2·s·Pa. More importantly, the films’ DPPH scavenging activity increased to the maximal levels of 85.45%. In short, these observations create a feasible strategy for preparing high-performance biodegradable active-packaging films.

Studies of the thermal protective performance of fabrics under fire exposure: from small-scale to hexagon tests

2017 ◽  
Vol 88 (20) ◽  
pp. 2339-2352 ◽  
Author(s):  
Sumit Mandal ◽  
Simon Annaheim ◽  
Thomas Pitts ◽  
Martin Camenzind ◽  
René M Rossi
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Radiant Heat ◽  
Air Permeability ◽  
Small Scale ◽  
Fire Exposure ◽  
Thermal Protective Performance ◽  
Flash Fire ◽  
Protective Performance ◽  
The Impact

This study aims to investigate the thermal protective performance of fabrics used in firefighters' clothing under high-intensity fire exposure. The performance of thermal protective fabric systems with different physical properties was evaluated under laboratory simulated fire exposure. Additionally, the influence of the configuration of the fire exposure tests and modes of heat transfer through the fabrics was also thoroughly investigated. The protective performance was evaluated using the standard small-scale flame [International Organization for Standardization (ISO) 9151:1995] and radiant heat (ISO 6942:2002) exposure tests. Additionally, the protective performance was evaluated under flash-fire exposure using a newly developed hexagon test. The protective performance values obtained from the small-scale (flame and radiant heat) and hexagon (flash fire) tests were compared and discussed. It has been found that a multi-layered fabric with high weight, thickness, and thermal resistance can significantly and positively affect the protective performance. If the air permeability of this fabric is high, it can show a lower protective performance; however, the impact of air permeability on the protective performance is insignificant especially in the case of the hexagon test. Notably, the protective performance can differ under two types of small-scale tests − flame and radiant heat. Also, this protective performance value is generally higher in the case of hexagon test in comparison with the small-scale tests. These differences in protective performance are mainly due to the unique configurations of these tests and/or different modes of heat transfer through the tested fabrics. The findings from this study will guide textile or materials engineers in the design and selection of materials for high performance thermal protective clothing; in turn, it will improve the occupational health and safety for firefighters.

scholarly journals Mitigating the Impact of Cellulose Particles on the Performance of Biopolyester-Based Composites by Gas-Phase Esterification

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 200 ◽  
Author(s):  
Grégoire David ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy
Keyword(s):  
Gas Phase ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Stress And Strain ◽  
Moisture Sensitivity ◽  
Natural Systems ◽  
Palmitoyl Chloride ◽  
Diffusion Parameters ◽  
Dispersion State ◽  
The Impact

Materials that are both biodegradable and bio-sourced are becoming serious candidates for substituting traditional petro-sourced plastics that accumulate in natural systems. New biocomposites have been produced by melt extrusion, using bacterial polyester (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)) as a matrix and cellulose particles as fillers. In this study, gas-phase esterified cellulose particles, with palmitoyl chloride, were used to improve filler-matrix compatibility and reduce moisture sensitivity. Structural analysis demonstrated that intrinsic properties of the polymer matrix (crystallinity, and molecular weight) were not more significantly affected by the incorporation of cellulose, either virgin or grafted. Only a little decrease in matrix thermal stability was noticed, this being limited by cellulose grafting. Gas-phase esterification of cellulose improved the filler’s dispersion state and filler/matrix interfacial adhesion, as shown by SEM cross-section observations, and limiting the degradation of tensile properties (stress and strain at break). Water vapor permeability, moisture, and liquid water uptake of biocomposites were increased compared to the neat matrix. The increase in thermodynamic parameters was limited in the case of grafted cellulose, principally ascribed to their increased hydrophobicity. However, no significant effect of grafting was noticed regarding diffusion parameters.

The Durability of Flame Retardant and Thermal Protective Cotton Fabrics during Domestic Laundering

2012 ◽  
Vol 441 ◽  
pp. 255-260 ◽  
Author(s):  
Wei Bang Chen ◽  
Ying Ying Wan ◽  
Fei Que ◽  
Xue Mei Ding
Keyword(s):  
Thermal Resistance ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Protective Clothing ◽  
Flame Retardants ◽  
Thermal Protection ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Before And After ◽  
Resistance Value

Flame retardant fabrics have been broadly used for protective clothing, which have strictly requirements on both flame retardancy and thermal protection. Usually, domestic laundering will be carried out frequently to clean these protective garments. However, little research on the performance durability of this type of fabrics after domestic laundering has been reported. This paper selected fabrics of 8 types of cotton and its blend fibers, which were treated with flame retardants Pyrovatex CP, Proban, CFR-201, SCJ-968 respectively. The damaged length, after flame time, after glow time, TPP value, thermal resistance value, weight, thickness, air permeability and water vapor permeability (WVP) of the samples were measured before and after 15 cycles domestic laundering cycles. Results show that the flame retardancy of the 8 fabrics reduce with launderings as measured by the increase in damaged length and after glow time. The TPP increase probably resulted from the increase in the thickness and thermal resistance of the finished fabrics. Domestic laundering resulted in only a slight change in the comfort properties of the fabrics.

scholarly journals Thermal resistance testing of standard and protective filtering military garment on the burning napalm mixture

2013 ◽  
Vol 67 (6) ◽  
pp. 941-950 ◽  
Author(s):  
Dusan Rajic ◽  
Zeljko Kamberovic ◽  
Radovan Karkalic ◽  
Negovan Ivankovic ◽  
Zeljko Senic
Keyword(s):  
Water Vapor ◽  
Thermal Resistance ◽  
Active Carbon ◽  
Thermal Protection ◽  
Water Vapor Permeability ◽  
Air Permeability ◽  
Resistance Testing ◽  
Vapor Permeability ◽  
Military Uniform ◽  
Sandwich Materials

Fires are an accompanying manifestation in modern weaponry use and in case of different accidents in peacetime. The standard military uniform is a primary barrier in protection of a soldier?s body from all external influences, including the thermal ones which can cause burns. The minimum thermal resistance to the effect of burning napalm mixture (BNM) in individual uniform garment materials has been determined, and is higher at simultaneous use of more materials one over another (the so-called sandwich materials), where the best thermal protection give sandwich materials with an air interspace. The requirement for the thermal resistance of the material of the filtrating protective suit (FPS) to the effect of BNM (? 15 s) has been fully met. The highest thermal resistance has been demonstrated by the FPS whose inner layer is made of polyurethane foam with active carbon. A proportional dependence between the thermal resistance of FPS to the effect of BNM and water vapor permeability through this garment mean has been determined, and reversed in respect to air permeability.

Heat-Related Illnesses

AAOHN Journal ◽  
2007 ◽  
Vol 55 (7) ◽  
pp. 279-287 ◽  
Author(s):  
Bonnie Rogers ◽  
Kristin Stiehl ◽  
Jennifer Borst ◽  
Andrea Hess ◽  
Shauna Hutchins
Keyword(s):  
Heat Stress ◽  
High Temperatures ◽  
Heat Exposure ◽  
Radiant Heat ◽  
Organ Damage ◽  
Interdisciplinary Teams ◽  
The Body ◽  
Stress Disorders ◽  
Physical Contact ◽  
Effective Manner

Heat-related illnesses can occur in workplaces where hot environments pose a threat to at-risk workers. Operations involving high air temperatures and humidity, radiant heat sources, direct physical contact with hot objects, or strenuous physical activities have potential for inducing heat stress in employees engaged in job functions in specific industries. Exposure to high temperatures can lead to a progression of symptoms in the body, which can result in widespread tissue damage, organ damage, and even death if not treated in a timely and effective manner. Strategies to reduce the effects of heat in the workplace include engineering controls, administrative controls, and personal protective equipment. Occupational and environmental health nurses must be able to recognize and treat the broad range of symptoms that can result from exposure to high temperatures. They must work together with interdisciplinary teams to provide training and education to the work force so that workers are able to take appropriate measures to prevent the onset of a heat-related illness, recognize the early symptoms, and seek treatment. Interdisciplinary teams must ensure that appropriate controls in the work environment reduce the risk of heat exposure and related heat stress disorders. Education and early intervention are key to avoiding heat-induced illness and eliminating or minimizing the effects of high temperature environments.

scholarly journals The Impact of the Mechanical Modification of Bacterial Cellulose Films on Selected Quality Parameters

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1275
Author(s):  
Izabela Betlej ◽  
Renata Salerno-Kochan ◽  
Agnieszka Jankowska ◽  
Krzysztof Krajewski ◽  
Jacek Wilkowski ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
Water Vapor Permeability ◽  
Quality Parameters ◽  
Vapor Permeability ◽  
Physical Parameters ◽  
Significant Information ◽  
Cellulose Films ◽  
Native Cellulose ◽  
Modified Polymer ◽  
The Impact

This study investigated the effect of the homogenization of bacterial cellulose particles and their reintegration into a membrane on the mechanical and physical parameters of the films produced from them in relation to films made of native cellulose (not subjected to the homogenization process). Bacterial cellulose was obtained from a culture of microorganisms forming a conglomerate of bacteria and yeast, called SCOBY. The research has shown that the mechanical modification of bacterial cellulose contributes to an increase in the elongation of the material. Modified polymer films were characterized by a higher Young’s modulus and a much higher breaking force value compared to native cellulose. The mechanical modification of cellulose contributed to an increase in hygroscopicity and changes in water vapor permeability. The obtained results may provide significant information on the methods of modifying bacterial cellulose, depending on its various applications.

scholarly journals The use of an internal airtight membrane in CLT external wall in terms of hygrothermal performance

2021 ◽  
Vol 2069 (1) ◽  
pp. 012208
Author(s):  
V. Kukk ◽  
J. Kers ◽  
T. Kalamees
Keyword(s):  
Water Vapor Permeability ◽  
Stochastic Approach ◽  
High Water ◽  
Vapor Permeability ◽  
Diffusion Resistance ◽  
Mold Growth ◽  
External Wall ◽  
Hygrothermal Performance ◽  
Dry Out ◽  
The Impact

Abstract This study focused on the dry-out capacity of the vapor-permeable CLT (cross-laminated timber) external wall and the impact of using an internal airtight membrane. The results of the work were obtained first from the field measurements, after which the simulation model was created and validated, and the hygrothermal performance of the wall was analyzed by a stochastic approach. The results of this showed that the CLT dries out quickly and safely in a wall assembly with a high water vapor permeability, even with the large range of initial CLT MC (13-25%). When an additional airtight layer with high vapor diffusion resistance (Sd of 244 m) is added between the insulation and the CLT, the dry-out capacity of the CLT decreases significantly and there is a high probability of mold growth on the CLT surface. The risk of mold growth can be prevented when the vapor resistance (Sd) of the airtight layer is reduced to 1.5 m in a case where initial CLT MC is up to 25% and in a case where initial MC is up to 20%, the vapor resistance of an airtight layer must be reduced to 3 m.

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