The effect of the transfer abilities of single layers on the heat and mass transport through multilayered outerwear clothing for cold protection

2017 ◽  
Vol 88 (10) ◽  
pp. 1125-1137
Author(s):  
Radostina A Angelova ◽  
Priscilla Reiners ◽  
Elena Georgieva ◽  
Yordan Kyosev

This paper deals with performance properties related to human thermo-physiological comfort of three-layer textile systems used for the production of outerwear for cold protection. The transfer of heat and fluids through the compound single layers (woven and non-woven) is investigated and compared to the heat and mass transfer of the systems for clothing. Six characteristics are measured for both single layers and systems of layers: thermal resistance, air permeability, water vapor resistance, relative water vapor permeability, the accumulative one-way transport index and overall moisture management capacity. For each of the characteristics, regression analysis is applied to prove or reject the proposed mathematical dependencies between the transfer abilities of the single layers and the respective systems. The results obtained showed that the fluid transfer abilities of the single layers applied in clothing for cold protection strongly affect the fluid transfer ability of the system of layers, while the heat transfer of the system is dominated by the heat transfer ability of the thermo-insulating layer. The proposed approach for assessment of the transfer processes through a system of layers for the production of outerwear for cold protection could be successfully applied in the design of other textile and clothing items, produced by using systems of different textile layers.

2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000 ◽  
Author(s):  
Nida Oğlakcioğlu ◽  
Ahmet Çay ◽  
Arzu Marmarali ◽  
Emel Mert

Engineered yarns are used to provide better clothing comfort for summer garments because of their high levels of moisture and water vapor management. The aim of this study was to investigate the characteristics of knitted structures that were produced using different types of polyester yarns in order to achieve better thermal comfort properties for summer clothing. However they are relatively expensive. Therefore, in this study engineered polyester yarns were combined with cotton and lyocell yarns by plying. This way, the pronounced characteristics of these yarns were added to the knitted structure as well. Channeled polyester, hollow polyester, channeled/hollow blended polyester, cotton, and lyocell yarns were plied with each other and themselves. Then, single jersey structures were knitted using these ply yarn combinations and air permeability, thermal resistance, thermal absorptivity, water vapor permeability, moisture management, and drying properties were tested. The results indicate that channeled PES fabrics are advantageous for hot climates and high physical activities with regards to high permeability and moisture transfer and also to fast drying properties. Besides, air permeability and thermal properties improved through the combination of lyocell yarn with engineered polyester yarns. However, the use of lyocell or cotton with engineered yarns resulted in a to a decrease in moisture management properties and an increase in drying times


2016 ◽  
Vol 87 (9) ◽  
pp. 1060-1070 ◽  
Author(s):  
Radostina A Angelova ◽  
Priscilla Reiners ◽  
Elena Georgieva ◽  
Hristina Plamenova Konova ◽  
Bianca Pruss ◽  
...  

This paper presents a comprehensive experimental study, conducted on a series of woven and non-woven fabric samples from different materials (cotton, polyester, and polyamide) and 14 three-layer systems of textile materials, used for production of outerwear clothing for protection from cold. Heat and mass transfer properties, related to the thermophysiological comfort of the outerwear clothing, namely conductive thermal resistance, water vapor resistance, relative water vapor permeability, air permeability, accumulative one-way transport of liquids, and overall moisture management capacity, were determined for the system of layers and the compound single layers. The transfer properties of the single layers were presented as a function of their thickness, mass per unit area, and areal porosity. The transfer properties of the system of layers were presented as a function of the thickness, mass per unit area, and bulk density of the systems. Regression analysis was applied to derive regression equations. The results obtained allowed assessment of the existence and trend of the influence, as well as evaluation of the strength of the dependences.


2020 ◽  
Vol 90 (17-18) ◽  
pp. 1987-2006 ◽  
Author(s):  
Tariq Mansoor ◽  
Lubos Hes ◽  
Vladimir Bajzik ◽  
Muhammad Tayyab Noman

The present study proposes a novel method to measure the thermal resistance and comfort properties of various sock samples under wet conditions. Theoretically, comfort properties are responsible for transporting moisture by our body with different rates. Therefore, plain socks with different fiber composition were wetted to a saturated level and after getting the required moisture content, the sock samples were characterized by Alambeta (for thermal resistance and thermal absorptivity) and Permetest instruments for relative water vapor permeability in the wet state. In addition, various skin models were utilized to make a comparison of thermal resistance in the dry state. Two different models were modified for analyzing the thermal resistance under wet conditions. According to the models used, the prediction of thermal resistance is a combined effect of the filling coefficient and thermal conductivity of wet polymers instead of dry polymers. With these modifications, the used models predicted the thermal resistance at different moisture levels with a significant correlation ( R2) value, that is, 0.84–0.97.


2019 ◽  
pp. 152808371987127
Author(s):  
Meisam Salmani Sangtabi ◽  
Mehdi Kamali Dolatabadi ◽  
Mohsen Gorji ◽  
Ali Akbar Gharehaghaji ◽  
Abosaeed Rashidi

This study aimed to examine the fabrication of bi-constituent nanofibrous membranes and investigation of their moisture management behavior in various environmental conditions. In doing so, polyurethane with a hydrophobic nature and superior mechanical behavior and poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) with a hydrophilic nature were utilized. Different hybrid electrospun nanofibrous membranes were aligned based on different layer arrangements and composition ratios. Then, the impacts of the solid fraction of polymers, sequence of stacking, and environmental conditions on water vapor permeability, contact angle, and acidic water permeation were measured and discussed. Tracing the water vapor permeability behavior in samples was carried out through measuring the amount of permeation hourly and proposing some regression models. Bi-modal nanofibrous membranes were successfully fabricated using PAMPS and polyurethane with an average fiber diameter of 543.5 and 216.7 nm, respectively. As the volume fraction of PAMPS increased, the porosities of the samples remained unchanged, the number of pores increased, and the pore size decreased (the average pore diameter was 299.97 nm for the PAMPS sample and 492.35 nm for the polyurethane sample). Despite the better water vapor permeability of the polyurethane membranes than that of the PAMPS membranes, in the first 12 h of the water vapor permeability test, the trend was completely reverse. The results also revealed that in the relative humidity of 55%, the polyurethane layer had the highest water vapor permeability among all samples. The results of the acidic water permeation and contact angle tests showed that the hybrid electrospun nanofibrous membranes exhibit better wicking and wetting properties.


2019 ◽  
Vol 31 (2) ◽  
pp. 272-283 ◽  
Author(s):  
Sibel Kaplan ◽  
Ceren Karaman

Purpose The purpose of this paper is to investigate thermal comfort performances of socks produced from cotton and regenerated cellulosic fiber yarns by thermal resistance (by a newly designed foot thermal manikin), moisture management tester (MMT) parameters and permeability (air and water vapor) tests. Design/methodology/approach Single jersey fabrics and socks were knitted from 30 Ne yarns produced from cotton, different regenerated cellulosic fibers (viscose, modal, bamboo, micromodal, Tencel®, Tencel LF®) and their blends. Thermal resistances of the socks were compared by a newly developed thermal foot manikin in a more realistic way than measurements in fabric form. Besides air and water vapor permeability, moisture management parameters of the fabrics were tested to differentiate performances of cellulosic fibers. Findings Results show that air permeability, liquid absorption and transfer parameters measured by MMT are generally identical and better for regenerated cellulosic fabrics than cotton. Micromodal and Tencel® have better performances for liquid transfer and overall moisture management capacities are superior for bamboo and Tencel LF®. Thermal resistances of the socks are minimum for Tencel LF® having a cross-linked structure and maximum for viscose socks. Originality/value It is thought that thermal resistance measured in socks form is more realistic than fabric measurements and results of this study that can be valid for all knitted garments. Moreover, comprehensive material plan of the study is valuable for getting reliable results for regenerated cellulosic fibers that have small differences in cases of thermal resistance and liquid transfer.


2011 ◽  
Vol 6 (4) ◽  
pp. 155892501100600 ◽  
Author(s):  
Elena Onofrei ◽  
Ana Maria Rocha ◽  
André Catarino

This paper studies the influence of fabric's structure on the thermal and moisture management properties of knitted fabrics made of two types of yarns with thermo-regulating effect: Coolmax® and Outlast®. The main purpose of this study was the selection of the most adequate fabric, to be used in summer and winter sportswear. The results demonstrated that some properties, such as, thermal properties, diffusion ability, air and water vapor permeability are influenced by both raw material type and knitted structure parameters. Wicking ability is influenced to a greater extent by the knitted structure, while the drying ability is primarily determined by raw material and to a lesser extent by the knitted structure parameters. Outlast® fabrics are preferred candidates for warmer climate sportswear, particularly due to their lower thermal resistance, higher thermal conductivity and absorptivity, air and water vapor permeability. When considering sportswear for colder weather, Coolmax® based structures seem to be the best choice. These findings are an important tool in the design of a sportswear product tailored to the different body areas thermal and moisture management requirements.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinshu Liu ◽  
Xiaoyan Ma ◽  
Wenzhao Shi ◽  
Jianwei Xing ◽  
Chaoqun Ma ◽  
...  

Abstract Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 602
Author(s):  
Carmen Rodica Pop ◽  
Teodora Emilia Coldea ◽  
Liana Claudia Salanţă ◽  
Alina Lăcrămioara Nistor ◽  
Andrei Borşa ◽  
...  

Kefiran is an exopolysaccharide classified as a heteropolysaccharide comprising glucose and galactose in equimolar quantities, and it is classified as a water-soluble glucogalactan. This work aimed to investigate the effect of different extraction conditions of kefiran on the structural and physical properties of the edible films obtained. Fourier-transform infrared spectroscopy and scanning electron microscopy were performed, together with a determinations of moisture content, solubility, water vapor permeability and degree of swelling. The kefiran films presented values of the water vapor permeability between 0.93 and 4.38 × 10−11 g/m.s.Pa. These results can be attributed to the development of a more compact structure, where glycerol had no power to increase the free volume and the water vapor diffusion through their structure. The possible conformational changes in the kefiran film structure, due to the interspersing of the plasticizers and water molecules that they absorb, could be the reason for producing flexible kefiran films in the case of using glycerol as a plasticizer at 7.5% w/w. Moreover, it was observed that the extraction conditions are a significant factor in the properties of these films and their food technology applications.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3090
Author(s):  
Anita Ptiček Siročić ◽  
Ana Rešček ◽  
Zvonimir Katančić ◽  
Zlata Hrnjak-Murgić

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al2O3 showed the lowest WVTR value.


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