Hafsa Jamshaid

A green material from rock: basalt fiber – a review

The nature is continually providing varied resources for creating textile materials for various applications. Although many textile fibers in the nature are provided with the fibrous kind itself it additionally offers raw materials that may be changed and formed into a filament in a way similar to the melt and solution spinning of other textile fibers. Basalt is an igneous rock, which is solidified volcanic lava. In recent years, basalt received attention as a replacement for asbestos fibers. Basalt has emerged as a contender in the fiber reinforcement of composites. Basalt fiber (BF) is capable to withstand very high temperature and can be used in high performance applications. This paper is review of state of art of knowledge of BF, the production methods, properties and its applications.

Aerogels for thermal insulation in high-performance textiles

ABSTRACT For many garment applications where protection is needed against hostile environments, part of the requirement is for insulation to shield the wearer from extremes of temperature. For an insulating garment to be fully effective, it needs to allow the wearer to move freely so that they can carry out their intended activity efficiently. Traditional materials achieve their insulation by trapping air within the structure thereby not only limiting heat loss by convection but also making good use of the low thermal conductivity of air to cocoon the wearer within a comfortable environment. To achieve effective protection with conventional textiles, it is usually necessary to have a thick fibrous layer, or series of layers, to trap a sufficient quantity of air to provide the required level of insulation. Several disadvantages arise as a result. For example, thick layers of insulating textile materials reduce the ability of the wearer to move in a normal manner so that the conduct of detailed manual tasks can become very difficult; the layers lose their insulating capacity when the trapped air is lost as they are compressed; the insulating capacity falls rapidly as moisture collects within the fibrous insulator – it does not have to become sensibly wet for this to happen; just 15% moisture regain can give a dramatic reduction in insulating capacity. Not surprisingly therefore, there has been continued interest in developing insulators that might be able to overcome the disadvantages of conventional textile materials and improve the mobility of the wearer by allowing the use of only a very thin layer of extremely-high insulating performance to provide the required thermal protection. One class of materials from which suitable candidates might be drawn is aerogels; their attractiveness derives from the fact that they show the highest thermal insulation capacity of any materials developed so far. Despite sporadic high levels of interest, commercialisation has been slow. Aerogels have been found to possess their own set of disadvantages such as fragility; rigidity; dust formation during working and cumbersome, expensive, batch-wise manufacturing processes. They may well have been destined to become a product of minor interest, confined to very specialist applications where cost was of little concern. However, methods have been developed to combine aerogels and fibres in composite structures which maintain extremely high insulating capacity whilst demonstrating sufficient flexibility for use in garments. Ways have been found to prevent the formation of powder as aerogel composite fabrics are worked. Most significant though, is the achievement, arising from a project supported by the Korean Government, of a simplified one-step production process developed with the express aim of providing a substantial reduction in the cost of aerogels. Suitably-priced aerogel is now available and this should provide fresh stimulus for research and development teams to engage in new product development work utilising aerogels in textiles and garments for thermal insulation. The mechanisms through which aerogels achieve their outstanding thermal insulating ability is unconventional, at least in terms of materials used in textiles. This issue of Textile Progress therefore includes detail about thermal transport in aerogels before reviewing the various forms in which aerogels can now be made, some of their applications and the research priorities that are now beginning to emerge.

Comparison of Regression and Adaptive Neuro-fuzzy Models for Predicting the Bursting Strength of Plain Knitted Fabrics

The aim of this study was to compare the response surface regression and adaptive neuro-fuzzy models for predicting the bursting strength of plain knitted fabrics. The prediction models are based on the experimental data comprising yarn tenacity, knitting stitch length and fabric GSM as input variables and fabric bursting strength as output/response variable. The models quantitatively characterize the non-linear relationship and interactions between the input and output variables exhibiting very good prediction ability and accuracy, with ANFIS model being slightly better in performance than the regression model.

In-situ development of highly photocatalytic multifunctional nanocomposites by ultrasonic acoustic method

Cotton-titania nanocomposites with multifunctional properties were synthesized through ultrasonic acoustic method (UAM). Ultrasonic irradiations were used as a potential tool to develop cotton-titania (CT) nanocomposites at low temperature in the presence of titanium tetrachloride and isopropanol. The synthesized samples were characterized by XRD, SEM, EDX and ICP-OES methods. Functional properties i.e. Ultraviolet protection factor (UPF), self-cleaning, washing durability, antimicrobial and tensile strength of the CT nanocomposites were evaluated by different methods. Central composite design and response surface methodology were employed to evaluate the effects of selected variables on responses. The results confirm the simultaneous formation and incorporation of anatase TiO2 with average crystallite size of 4nm on cotton fabric with excellent photocatalytic properties. The sustained self-cleaning efficiency of CT nanocomposites even after 30 home launderings indicates their excellent washing durability. Significant effects were obtained during statistical analysis for selected variables on the formation and incorporation of TiO2 nanoparticles (NPs) on cotton and photocatalytic properties of the CT nanocomposites.

Thermal and mechanical characterization of novel basalt woven hybrid structures

This paper presents a study conducted on the thermal and mechanical properties of basalt hybrid and nonhybrid woven structures. While designing fabrics for various industrial textile applications, the knowledge about the mechanical properties is very important. Strength, modulus, and elongation are the most important performance properties of fabrics governing their performance in high-end applications. The thermal properties of the fabrics, i.e. thermal resistance, thermal conductivity were also studied vis-a-vis physiological behavior. In this work, state-of-the-art evaluation techniques are used, which provide reliable nondestructive measurement of thermal conductivity, thermal resistance, water vapor permeability, and air permeability of fabrics. The effect of structure and composition on the above-mentioned properties of such nonstandard fabrics has been investigated in detail. The results of the study show that effect of fiber composition, weave, and geometrical parameters on thermal and mechanical properties is significant in basalt hybrid fabrics.

Mechanical, thermal and interfacial properties of green composites from basalt and hybrid woven fabrics

Composites based on pure Basalt and Basalt/Jute fabrics were fabricated. The mechanical properties of the composites such as flexural modulus, tensile modulus and impact strength were measured depending upon weave, fiber contents and resin. Dynamic mechanical analysis of all composites were done. From the results it is found that pure basalt fiber combination maintains higher values in all mechanical tests. Thermo-gravimetric (TG/DTG) composites showed that thermal degradation temperatures of composites shifted to higher temperature regions compared to pure jute fabrics. Addition of basalt fiber improved the thermal stability of the composite considerably. Scanning electron microscopic images of tensile fractured composite samples illustrated that better fiber-matrix interfacial interaction occurred in hybrid composites. The thermal conductivity of composites are also investigated and thermal model is used to check their correlation.

End use performance characterization of unconventional knitted fabrics

This paper presents a study conducted on the mechnical and functional properties of unconventional knitted structures. The raw materials selected for investigation were basalt single jersey and 1×1 rib, polypropylene single jersey and 1×1 rib, polyester single jersey and 1×1 rib and jute single jersey and 1×1 rib. The mechnical properties like bursting strength and shear strength were studied. The thermal properties of the fabrics i.e., resistance & conductivity were studied vis-a-vis physiological behavior. Electrical and accoustic properties were studied as well. On the basis of the results, the influence of the fabric structure on various property parameters were analyzed. The results indicate that effect of fiber and knitted fabric structure on mechanical and functional properties are significant. It can be concluded that rib fabrics have overall better properties as compared to single jersey knitted fabrics. The aim of this study is to analysis the properties of unconventional knitted fabric for using them in technical applications i.e. composites.

Reducing defects in textile weaving by applying Six Sigma methodology: a case study

Textile and clothing account for more than 50% of Pakistans exports. However, total share of Pakistani exports in the global textile and clothing market is less than 1%. One of the reasons of this low share is the manufacturing of less value–added products; another reason is the poor quality of some product categories. Although the country produces some of the worlds best quality yarns due to well–organised spinning sector, the quality of some fabric categories produced in the country is not as good because of the sector being less–organised and poorly managed. The objective of this study was to explore the application of Six Sigma methodology for reducing the defect percentage in fabric manufacturing sector. A representative textile weaving unit was selected for this study and it was found that by the suitable application of Six Sigma tools, the sigma level was improved from 2.2 to 3. Profit per month was observed to be increased worth

Photoilluminance of Different Woven Structures by Treatment with Phosphorescent Pigment

26,000.

Sonochemical synthesis of highly crystalline photocatalyst for industrial applications

The work is focused on study of photoilluminance of woven fabrics. Plain, twill, and matt woven structures are investigated after application of the phosphorescent agent. Samples were kept under observation for different periods of time in completely sealed box where light couldn’t enter from any side. Lux meter was used to measure the intensity of light. As the charging time increases, glowing time also increases and the weave structure having greater capacity to absorb light radiations from the source, glows for a longer duration of time. The weave having larger number of intersections facilitates greater absorption of light photons and the weaves having relatively lower number of intersections have a smaller capacity to absorb light radiations. Longer yarn floats in the fabric, tend to reflect higher portion of light, which in turn causes less charging of the phosphorescent fabric. Thus a shorter glow time is observed. Tensile and tear strength was mesaured for all fabric samples before and after application of phosphorescent pigment so as to observe the effect of treatment on mechanical properties.