Manas Sarkar

Transplanar water transport tester for fabrics

This paper reports on a novel instrument for measuring the water transport behaviour of fabric or paper materials in the transplanar direction. The instrument is unique in that it can not only measure the initial water absorption of the fabric in the transplanar direction, but also the rate of evaporation from the fabric surface after fully saturated with water, with the temperatures of water controlled at different levels simulating the end use conditions of the fabric. Compared with existing instruments for the water transport behaviour of fabrics or papers, the new instrument has a unique mechanism to control the water level underneath the fabric sample at a constant level (i.e. the water level is not reduced with the water transport into or through the fabric sample); as a result, the measurements are not affected by the changes of hydrostatic water pressure during testing. Repeated tests on various fabric samples showed that the measurements from the instrument are accurate, sensitive and reproducible.

Biomimetics of Plant Structure in Knitted Fabrics to Improve the Liquid Water Transport Properties

Biomimetics of the branching structure of a plant can improve the water absorption and one-way transport property of the fabric. The present work focused on the development of a branching network in knitted fabrics to improve liquid water transport properties. Fabrics developed with such a branching structure and made from different combinations of yarns exhibited faster water absorption and improved moisture management property, as measured on the Transplanar Water Transport Tester and Moisture Management Tester. Furthermore, the novel structure also improved the air permeability of the fabric. The improved water absorption rate, moisture management property and air permeability are beneficial to clothing comfort.

Biomimetics of branching structure in warp knitted fabrics to improve water transport properties for comfort

Biomimetics of a plant branching structure in textiles can enhance the water transport property, being beneficial to wear comfort. In this work, a unique two-layered structure was developed, on a double-needle bed warp knitting machine. In this structure, two yarns are combined together in the inner layer to form loops and are separated into individual yarns to form two loops in the outer layer. Using different combinations of methods of transferring the yarns from the inner layer to the outer, four types of branching-structured fabrics were developed and the water transport properties of these structures were compared against those of the standard interchanging fabrics. The systematic measurements of various water transport properties, in terms of wicking rate and wetting area, demonstrated that warp knitted fabrics with branching structure absorbed water faster than the corresponding interchanged plain knitted fabrics. The plant-structured knitted fabrics also have lower values of air resistance, which is beneficial to summer wear. It is believed that the new developed fabrics have advantages for sportswear and summer casual wear.

Plant-based biomimetic branching structures in knitted fabrics for improved comfort-related properties

The use of plant-based biomimetic branching structures in textiles can enhance their water absorption and one-way transport properties. In this study, double-layered knitted structures were developed in which two or more yarns were combined at the technical back of the fabric and separated at the technical face to emulate plant-like branching networks. Fabrics with these novel knitted structures were produced on a circular knitting machine. The water absorption and transport properties of these fabrics were measured and it was showed that plant-based knitted structures with two or more branching networks had faster water absorption and better moisture management properties than the conventional structure knitted fabrics. Other comfort-related properties, such as air resistance, were also better for the newly developed fabrics. These novel knitted fabrics should therefore have potential advantages and benefits in terms of the comfort of sportswear and functional clothing.

Effect of softeners and crosslinking conditions on the performance of easy-care cotton fabrics with different weave constructions

This study reports an experimental investigation on the effect of softeners, crosslinking conditions, and laundering on the comfort related and low stress mechanical properties of cotton fabrics with different weave constructions. Softeners with different chemical natures, in conjunction with the crosslinking agent and catalyst, were padded onto the cotton fabrics of three types of weave constructions, viz. plain, twill, and a newly developed plant-structured weave design. Two crosslinking conditions, namely dry and moist curing conditions, were compared. Scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscope were used to visualize and quantify the morphological and chemical changes on fabrics. The experimental results showed that the dry-crosslinking condition is preferable to achieve better comfort and easy-care properties, while moist-crosslinking condition is a better choice when strength-related properties are the main requirement. The study further showed that silicone elastomer softener can be applied to improve fabric strength whereas micro-emulsion of functional amino-polysiloxane plus emulsion containing polyalkylene is beneficial for comfort characteristic. The plant-structured cotton fabric finished in the dry-crosslinking condition with softener in nano-emulsion form can result in superb water absorption, excellent air permeability, good handle, acceptable strength, and improved easycare property.

Flammability, comfort and mechanical properties of a novel fabric structure: plant-structured fabric

Traditional flame retardant (FR) treatments may bring detrimental effects on comfort as well as mechanical properties for cotton fabrics. This study investigates whether a novel fabric structure—plant-structured fabric can improve fabric performance after FR treatment. Here, plant-structure fabrics were compared with conventional fabrics of similar weight and thickness. The results revealed plant-structured fabrics tended to retain a higher level of comfort properties than the conventional plain and twill weave fabrics on wettability, thermal conductivity, air resistance and fabric hand feel. Moreover, the tearing strength and tensile strength of the plant-structured fabrics are strongly associated with a higher level of flame resistance as evaluated by the 45° flammability test. This can be attributed to higher fabric sett, the presence of closed pores between the two layers and lower open pore volume at its face. The weave pattern of fabrics was observed through microscope and the thermal decomposition behaviour of fabrics was evaluated by thermal gravimetric analysis.

Antecedents to India's textile exports: 1985?2005

Indias wealth in cotton resources has enabled the labour-oriented textile industry to become a significant contributor to the economy and employment of the country. In 2005, Indias textiles export value to the world amounted to the US

Moisture-responsive Fabrics Based on the Hygro Deformation of Yarns

8.3 billion, which represented 16% of its commodity exports. In this paper, using the data from 1985 to 2005, the economic factors affecting the textile exports between India and its top 10 importers are analysed using the gravity model with Ordinary Least Squares (OLS) technique and panel data estimation approach in order to identify the impact of the major factors that underpinned Indias textile exports. The results indicate a strong support for the gravity model and illustrate that the determinants including Gross Domestic Product (GDP), real exchange rate, per capita GDP and population growth rate of the importers all have a significant impact. In contrast, the introduction of the Euro has indicated a negative effect while the formation of the World Trade Organisation shows no obvious influence in Indias textile trading.

Biomimetics Of Tree-shaped Branching Structure In Textile Fabrics

Moisture-responsive fabrics have great potential in the development of smart clothing which can respond to changes in the physiological conditions of the wearer and environmental conditions so as to achieve maximum comfort. In this research, the reversible dimensional changes of hygroscopic yarns are utilized to develop responsive fabric structures which widen or narrow their openings depending on moisture content. Experiments showed that these novel fabrics exhibited improved air permeability at higher moisture content, which may be associated with body sweating or a hot, humid climate. The improved air permeability can enhance body cooling for better comfort.

Biomimetics of Plant Structure in Textile Fabrics for the Improvement of Water Transport Properties

Water transport properties of fabrics are critical to wearing comfort. A tree-shaped branching network, which exists widely in nature, is known to have an extremely efficient transport system. The emulation of the treeshaped branching structure in textile fabrics has the potential of developing fabrics with superb liquid water transport properties for enhanced comfort. Here, we report on the development of some novel multilayer woven and knitted structures which mimic the branching structure. Experimental investigations have shown that the fabrics with such new structure have clearly faster liquid water transport and better moisture management property. These new fabrics are being commercialized.