This paper describes basic principles and techniques involved in designing waterproof breathability fabrics. Breathable fabrics are available in a large variety, which can be categorized as — closely ...woven fabrics, microporous membranes and coating, hydrophilic membranes and coating, combination of microporous and hydrophilic membranes and coating, use of retroreflective microbeads, smart breathable fabrics and fabric based on biomimetics. Basic principles and mechanisms of water vapor transmission solely depend on the type of breathable fabrics. The formulation and application of microporous and hydrophilic membranes and coatings have been well researched in different fields of application. Smart breathable fabric and fabric based on biomimetics, which are of recent origin, are also showing their potential. The technology is continuously evolving in the areas of a cost-effective manufacturing process, improving material formulation to enhance the film's properties, and controlling pore sizes and their distributions, developing improved monolithic film and coating materials for a variety of applications. Method of incorporation of membrane, coating techniques, fabric substrate, lining material and above all the garment construction are also undergoing changes and play vital role in designing breathable garments.
Biodegradable jute geotextiles (JGTs) are an effective reinforcing material for unpaved roads, but its serviceability is limited because of faster microbial degradation. Different methods are in use ...to improve the serviceability of jute geotextiles. In this paper, the influence of CA-chitosan treatment, road design, and rainfall intensity on the time-dependent serviceability of JGTs has been studied. Chemically treated jute geotextiles are laid in unpaved road designs with and without sand layer, for 30, 60, and 90 days' duration, and are exposed to simulated rainfall intensities of 50 and 100 mm/hr. With an increase in time of usage, breaking load and puncture resistance decrease due to microbial attack, and pore size decreases due to clogging of soil in JGTs. Chemical treatment is observed to have a greater influence on the serviceability, followed by the presence of a sand layer in road design and the rainfall intensity and shows retention % in tensile strength of 87.42% and 91.21% after 30 days duration. Further, the overall performance of CA-chitosan treated JGTs is observed to be better than untreated JGTs.
Coir is a lignocellulosic fiber which is quite preferable in the production of biofuels and chemicals. Conversion of cellulose and hemicellulose to biofuels requires five main unit processes out of ...which, pretreatment plays a major role because all subsequent processes depend upon the pretreatment results. Partial degradation of lignin, hemicellulose, and breakdown of the sugars also occur during the pretreatment of the coir. So, the optimal condition selection is vital. In this paper, an attempt has been made to optimize the parameters (time, NaOH concentration, and temperature) by Box-Behnken design in order to get the optimum level of lignin, hemicellulose, and cellulose. To obtain an ideal solution, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is used to rank the optimized solutions. Further, to find the authenticity of TOPSIS, the top three ranked solutions are again tested. It is observed that error percentage increases with an increase in rank order.
This paper presents the use of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method to determine the optimum time, NaOH concentration, and temperature for reduction in ...lignin content, reduction in flexural rigidity, and tenacity of the coir yarns using box-behnken design. Optimum conditions for better properties are obtained from the ramp graphs. The results indicate that the TOPSIS method is appropriate for solving the multi-criteria optimization of the process parameters based on ranking system. The optimal value for time, concentration, and temperature are 3 h, 5% NaOH, and 80°C based on the defined criteria.
Geomeshes made up of coir fibers are a possible great alternative before vegetation establishes itself, and provides immediate soil erosion control on different types of slopes. In this study, coir ...geomeshes structure has been modified for better erosion over different soils. Different structurally modified coir geomeshes are tested for runoff erosion control, culmination discharge over loamy sand, silt loam, and silty clay loam soil at different slope angles. Lowest erosion control is observed over loamy sand due to higher amount of sand percentage. To know the overall effect of geomeshes, germination tests are also performed. It is observed that twill weave of coir geomeshes provides better erosion control due to the higher float length at the backside which reduces the water velocity. Twill weave geomeshes also provide better germination than plain and satin woven geomeshes. Overall, twill weave geomesh is preferred over loamy sand, silt loam, and silty clay loam at lower and medium slope angles.
This article describes engineering design of waterproof breathability fabrics
specifically designed for leisure, medial uses and survival clothing. In many
applications, breathable fabrics not only ...satisfy water-vapor permeability but also
a number of other functional characteristics. Garment design, cut and fit, design of
seam, constituent of multilayer structure and various forms of ventilation system
are often modified depending on the functional requirement. In the comparative
evaluation of several breathable fabrics, it is often very difficult to suggest the
product which performs best. The conditions of application and corresponding
requirements imposed on the product are quite different depending on the end
use.
Soil erosion is a serious environmental problem that can be controlled using bioengineering techniques. In using a bioengineering technique, temporary reinforcement is performed with geomeshes until ...vegetation takes root. In this study, structurally modified jute and coir geomeshes were tested for runoff erosion control and runoff volume over loamy sand at different slope angles. The laboratory results revealed that all parameters (slope angle, type of weave and type of material) had a significant effect on the erosion control performance of geomeshes. The slope angle contributed most (52.34%) to runoff erosion control, followed by weave type (25.79%) and type of material (12.28%). At lower and medium slope angles (of 15o and 30o, respectively) the twill-woven structure of coir geomeshes provided better erosion control than plain- and satin-woven structures, while plain-woven jute geomeshes demonstrated better erosion control at all slope angles. To understand the overall impact, a germination test was also conducted. According to the germination test results, the twill weave of jute geomeshes provided the highest rooting length. In general, plain-woven jute geomeshes are preferred for better erosion control on a high slope angle, while plain and twill can be used on a low slope angle.
In this study, runoff erosion control performance of different coir and jute geomeshes is studied at different slope angle, rainfall intensity, and soil-infiltration conditions using a runoff erosion ...control tester (based on ASTM D 7101). It is observed that the erosion control percentage under soil-infiltration conditions is lower at higher slope angle and rainfall intensity, due to the higher water flow velocity, and because of the same reason runoff volume under zero-infiltration conditions is higher. It is also observed that the geomeshes with higher weight per unit area results in lower runoff and higher culmination, due to the higher storage volume and restriction offered by larger diameter weft yarn of higher weight geomesh.
Needle thread loses significant strength when incorporated into the seam. The needle thread being weaker tends to fail under load which results in a catastrophic failure of the seam. The use of a ...lower linear density bobbin thread is suggested in order to balance out the loss in the needle thread, which can help improve the production efficiency without compromising the seam strength. In this paper, four combinations of needle/bobbin threads are used at various process parameters to study the impact of a lower linear density bobbin thread on the seam strength. The seam strength prediction in such an asymmetrical combination of the needle and bobbin thread is also a subject of exploration in this paper as previous research has only taken place in an ideal situation where the same needle and bobbin threads were used.
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