Management of Technology and Innovation, Fluid Flow and Transfer Processes, Industrial and Manufacturing Engineering, Engineering
22
Scopus Publications
Scopus Publications
Breathability and Dynamic Evaporative Cooling Heat Flow of a Ripstop Defence Fabric Sofien Benltoufa, Hind Algamdy Tekstilec, 2025 This study investigated the breathability and dynamics of evaporative cooling heat flow through a defence fabric. Two ripstop fabrics were developed by changing the floats in the delimiting plain grid. The influence of fibre kinds was studied using weft threads made of 100% cotton, 65% polyester/35% cotton and 100% polyester. First, the breathability of used materials was evaluated using relative water vapour permeability (RWVP), resistance (Ret) and air permeability. Second, a more in-depth examination was conducted using evaporative cooling heat flow kinetics, and certain distinguishing variables that describe the various evaporative cooling heat flow phases were found. Those parameters consider the evaporative heat flow at 0 seconds, defining the skin’s first contact and the time spent to reach equilibrium. The results demonstrated that adding polyester to a fabric makes it more breathable, cooler, faster drying, and provides a more refreshing sensation on initial contact with the skin. Adding floats to the delimiting plain grid reduces the fabric's porosity and breathability.
Dynamic thermo-physiological comfort of a recycled Denim nano-layered fabric SOFIEN BENLTOUFA, HIND ALGAMDY Industria Textila, 2025 This study investigated the dynamic thermo-physiological comfort of a recycled Denim nano-layered fabric. The top layer of the Multilayered Denim fabric was recycled Denim. The semi-permeable nanomembrane was chosen due to its high- water vapour permeability and waterproof properties. A nonwoven fabric was added to the garment as an extra layer to provide shape and support and avoid direct contact with the skin. A double-faced adhesive grid was used to ensure bonding between the various layers. The breathability of used fabrics was studied based on the air permeability, water vapour resistance, and relative permeability using the Permetest according to the ISO 11092 standard. To study the dynamic of the thermo-physiological comfort, the dynamic cooling heat flow during evaporation was visualised. Results showed adding a semi-permeable nanolayer decreased the air permeability by about 16% compared to a simple Denim fabric. Conversely, the water vapour permeability was enhanced to 48% when the nanolayer foil was added. It was found that a multilayered Denim fabric had a better cooling feeling at the skin’s first contact stage and equilibrium compared to a simple fabric.
The effect of fabric parameters on the evaporative cooling heat flow kinetics SOFIEN BENLTOUFA, HIND ALGAMDY Industria Textila, 2025 This study explored how fabric parameters and walking speed affect the dynamics of evaporative cooling. Walking speed is equivalent to 1 m/s, while running speed is 2 m/s. Knitting fabrics made from natural and synthetic fibres were used to examine how hydrophilic and hydrophobic properties influence evaporation. Visualising the evaporative cooling heat flow kinetics allowed us to identify different evaporation stages. We defined new parameters: Qmax , Qmin , Qeq , Flow drop (Qmax – Qmin ), and equilibrium time. Qmax represents the thermal absorptivity of water vapour at the very first moment of contact between the fabric and the skin. Qmin signifies the decrease in the cooling flow. Teq denotes the equilibrium time. These parameters describe the dynamics of water vapour transfer. The results showed that incorporating synthetic fibres into a fabric enhances its breathability, lowers the temperature, accelerates drying, and provides a refreshing sensation when first touched by the skin. It was found that Coolmax is twice as cool as wool.
The water vapour resistance dynamic measurement of natural and synthetic fibre Sofien Benltoufa, Hind Algamdy, Adel Ghith, Faten Fayala, Lubos Hes International Journal of Clothing Science and Technology, 2024 PurposeThe paper aims to investigate the dynamic measurement of the water vapour resistance. The water vapour diffusion kinetics depends on the fibre’s material. So, water vapour resistance measurement times till the equilibrium steady state can vary in the case of natural fibres compared to synthetic fibres. Devices for determining water vapour resistance according to the ISO 11092 standard allow static values to be measured.Design/methodology/approachIn this study to investigate the dynamic of the water vapour resistance, a new parameter named “holding period” was introduced and defined as the time from sample placement on the measuring head until the measuring process begins. The holding period was varied as 0, 30, 60, 90, 120, 180, 240 and 300 s. Wool and cotton knitted fabrics were tested as natural fibres and compared to 100% polyester and 90% polyester/10% elastane as synthetic fibres. Measurements were conducted under both air velocities of 1 and 2 m/s. The experimental test data were statistically analysed based on ANOVA and four-in-one residual plots.FindingsStatistical analysis of experimental tests shows that the holding period affects water vapour resistance in both air velocities of 1 and 2 m/s and on the measured values in the case of hydrophilic fibres.Research limitations/implicationsThe study of the dynamic relative water vapour permeability of natural and synthetic is an important area of interest for future research.Practical implicationsIt is recommended to hold the samples on the top of the head measurement before starting the test.Originality/valueFollowing the ISO 11092 standard, the static values of the water vapour resistance were measured without considering the dynamic behaviour of the water vapour diffusion through the textile fabrics. This paper fulfils an experimental dynamic measurement of the water vapour resistance.
Effect of knitting structure and dyeing process on drying time, air and vapor permeability Mohamed Ghaith Chakroun, Sofien Benltoufa, Adel Ghith, Faten Fayala Textile Research Journal, 2024 Comfort is the prime need in clothing. It is affected by the properties of fibers, yarns, and fabrics. A good understanding of these factors is essential in the design and conception of functional clothes. Fabric design serves as a manufacturing tool to meet several end-use requirements. The construction specifications and design of knitted fabrics greatly influence the comfort level of the end-use garment. This study aims to investigate the effect of the knitting stitch type and the dyeing process on the clothing comfort of knitted fabrics. For this purpose, five structures were prepared by combining plain, float and tuck stitches: plain jersey, cross miss 1 × 1, single cross tuck, weft lock knit and Lacoste. Then, yellow, and black dyeing were applied. The investigated wear comfort properties were the drying time, the air permeability and the relative water vapor permeability. Tests were conducted on the finished and on domestically washed fabrics. The data obtained were statistically evaluated with Pearson correlation, paired t-test, analysis of variance analysis and the Tukey test. The results showed that tucked fabrics have the longest drying time combined with the lowest air and water vapor permeability. Black variants showed better drying behavior and higher water vapor permeability. Analysis of variance results showed that the structure has a significant effect on clothing comfort. However, the dyeing process exerts a significant influence only on the drying time and the relative water vapor permeability. The paired t-test results indicate that the domestic washing cycles significantly change the drying time and the air permeability of knitted fabrics.
The dynamic of cooling heat flow of simple jersey polyester fabric SOFIEN BENLTOUFA Industria Textila, 2024 The dynamic of cooling heat flow during evaporation of the simple jersey polyester fabrics was investigated in this study. The holding period as a new parameter was introduced to study the dynamic of cooling heat flow during evaporation from the skin through the jersey knitted fabric. The holding period intervals were chosen as follows: 0, 30, 60, 90, 120, 180, 240 and 300 seconds. The Permetest skin model was used to study and visualize the dynamic of the cooling heat flow at different holding periods. Results demonstrated that adding elastane makes fabrics less cool. Three different stages were noticed concerning the cooling heat flow dynamic: the first with a maximum heat flow (Qmax) indicating the first contact properties of a textile material with the skin. The second is a transition phase where the cooling heat flow decreases to the minimum heat flow (Qmin), and then it reaches the equilibrium (Qeq) mentioning the beginning of the third stage with a constant heat flow. It was found that the holding period does not affect the measured water vapour resistance, in the case of polyester jersey fabrics.
Textile fabric's in-plane water permeability determination during wicking SOFIEN BENLTOUFA, AYMAN ALFALEH Industria Textila, 2024 Based on a mathematical formulation of the water flow for different wicking configurations (ascendant-horizontal and descendant), a combined ascendant, horizontal and descendant wicking experimental test was designed to provide detailed measurements of the pertinent wicking performance properties: capillary pressure and in-plane direction permeability. This method was proposed due to capillary flows found in standard vertical wicking tests as well as erroneous assumptions made in other wicking tests. The effective capillary radius was assumed to remain constant as the height of the liquid increases. This assumption would suggest that saturation, capillary pressure, and permeability are also constants. However, experiments show that these properties are only constants in the case of the descendant wicking when liquid front height is varied. The capillary pressure and permeability calculations were made using Darcy’s law and the Lucas-Washburn equation as a function of the saturation level. In the combined wicking test, conducting a horizontal wicking test allows us to calculate the effective capillary radius of a fabric as the saturation rate was found to be constant, which in turn can be used to solve for capillary pressure. That capillary pressure can then be used in a descendant wicking test, where the liquid front flow and the saturation rate remain constant, and Darcy’s law to solve for permeability. A series of experiments was conducted on cotton jersey knitting. The results showed that the ability to wick the water depends on pore size and porosity scales: macro and micropores. The in-plane water permeability was found to be directly related to the saturation rate.
Evaporation coefficient determination during the capillary rise Ayman Alfaleh, Sofien Benltoufa, Faten Fayala Textile Research Journal, 2023 Thermo-physiological comfort refers to the heat and moisture transport properties of clothing and how the clothing helps maintain the body's heat balance during various activities. To maintain the thermoregulation of the body, the resulting sweating should be absorbed by wicking fabrics close to the skin and evaporated to the ambient air. In this study, a mathematical model was developed considering evaporation during the capillary rise, based on the geometric configuration of a jersey-knitted fabric and taking evaporation into account. This model was used to calculate the evaporation coefficient. Based on the activities of the worker, sweat diffusion is controlled by capillary diffusion and moisture evaporation. The effect of air velocities of 0 m/s, 1 m/s, and 2 m/s, representing non-walking, walking, and running activities of a worker, respectively, was studied during capillary diffusion. The experiments were conducted at different relative humidities. The results show that the evaporation coefficient depends on the worker’s activities and the relative humidity ratio.
Thermo-physiological comfort of brushed woven fabrics Vlakna A Textil, 2018
From smart campus to smart city: Monastir living lab Ahmed Noureddine Helal Sofien Benltoufa, Fadhel Jaafar, Mohsen Maraoui, Lamia Said, Mounir Zili, et al. Proceedings of 2017 International Conference on Engineering and Technology ICET 2017, 2017
