Asis Patanaik

Nanotechnology in fibrous materials–a new perspective

This issue reviews various areas where nanotechnology has come up predominately in fibrous materials, namely in electrospun polymeric nanofibers and polymer layered silicate nanocomposites. It includes synthesis, characterization, various methods of collecting nanofibers, factors affecting electrospinning, methods of increasing the productivity of the electrospinning process, and different electrospinning designs. It also covers synthesis and characterization of polymer nanocomposites. Various properties of nanocomposites are discussed. The rheological behavior and morphology of nanocomposites are covered. Different modeling and simulation methods applicable to electrospun nanofibers and polymer layered silicate nanocomposites are discussed. Some of the potential application areas of electrospun nanofibers, polymer layered silicate nanocomposites, and various products available in the market based on nanotechnology are also discussed. Some of the lacking areas and future prospects in nanofibrous structures (nanofibers and nanocomposites) are emphasized in this issue.

Optimization of Electrospinning Parameters for Chitosan Nanofibres

Copyright: 2011 Bentham Science Publishers. This is the pre print version of the work. The definitive version is published in Current Nanoscience, Vol. 7(3), pp. 396-401

Simulation of Airflow in Nozzle-ring Spinning using Computational Fluid Dynamics: Study on Reduction in Yarn Hairiness and the Role of Air Drag Forces and Angle of Impact of Air Current

In this paper we report on computational fluid dynamics (CFD) simulation of airflow inside the nozzles used in Nozzle-Ring spinning. Using the CFD, air velocities at different locations of the nozzle were obtained and then drag forces acting on hair and yarn were computed. Z-twisted carded cotton yarns were produced at ring spinning machine with and without placing nozzle. Three nozzles were used, each having air inlets at different axial angle. Using the results of simulation, the role of air drag forces and angle of impact of air current on reduction in yarn hairiness could be explained. Nozzle-Ring yarns had a lower number of S3-hairs than the regular ring yarn. The drag forces played a dominant role in reducing the hairs. The angle of air inlets controlled the impact angle of air on the hair. At very high impact angle, curving of protruding hair was bound to occur during its folding, signifying the difficulty in wrapping the hair over the yarn and, hence, a lower reduction in hairiness.

Some Studies on Water Permeability of Nonwoven Fabrics

In this paper we report on the water permeability behavior of nonwoven fabrics produced from flax fibers. Three different types of needle punched nonwoven fabrics are produced by varying the depths of needle penetration during the needle punching process. The pore size and its distribution in the nonwoven fabrics are measured by liquid extrusion porometry. Water permeability is measured by the water permeability testing instrument working on the principle of falling hydraulic head method. A finite element analysis is employed to predict the flow velocity through the nonwoven fabrics. A good correlation is achieved between the average velocity data obtained from water permeability test and theoretical prediction based on finite element analysis. The pore size and its distribution play an important role in water permeability characteristics.

Experimental Measurement and Prediction of Thermal Resistance in Paratrooper Clothing

Combat free fall (CFF) paratrooper’s protective clothing comprising of nonwoven fabric, combinations of inherently flame retardant Nomex ® fabric, and cotton fabric are studied under simulated conditions (wind velocity) of conduction using Thermolabo-II technique. Theoretical predictions of thermal resistance using mathematical modeling have also been carried out by taking into consideration important parameters that affect the functional performance. The results showed that nonwoven insulating fabrics exhibit high thermal resistance in dry contact method under moderate wind velocity and the values predicted by modeling confirm the same.