Chitosan nanofibrous materials for chemical and biological protection

Chitosan derivatives are difficult to electrospun because they have poor flexibility of their polyelectrolyte chains. Based on extensive trails, we have successfully electrospun chitosan polymer and, subsequently, coated on non-woven polypropylene utilizing Nanospider technology. This experimentally developed nanofibrous webs of various densities were coated on non-woven fabric and, subsequently, stitched with activated carbon sphere (ACS) adhered composite fabric. Biological filtration and chemical protection were evaluated and the optimized density offering the highest value with meeting specified comfort was assessed. Results showed that optimized web morphology of 0.43 g m−2 is the best for integration with nuclear, biological and chemical absorbent layer of low ACS add-on in all aspects of comfort and protective behaviours. This will be meeting stringent defence protective requirements and lowering down the weight of suit by approximately 25%. An attempt has also been made in this research to protect from sulphur mustard chemical warfare agent by using both theories: (a) barrier techniques and (b) disintegrating the trapped molecules via functionalization of the web. Result shows that first molecules get trapped by in web layer (barrier effect) and subsequently destroyed by hydrolysis mechanism. Scanning microscopic image shows web is acting as barrier layer by trapping sulphur mustard particles. Optimized web of 0.43 g m−2 was functionalized with zinc (Zn) oxide and the presence of Zn particles was confirmed by imaging techniques. Crystalline and thermal analysis depicts that structural changes were found in sulphur mustard spotted functionalized web. Raman spectra show chemically disintegrated hydrolysed products of sulphur mustard. Bacterial filtration efficiency, antimicrobial and comfort properties were measured for assessing the introduction of nanowebs for biological protection and chemical protection in newly created multilayered fabric structure with low ACS add-on (180 g m−2). The initial encouraging outcome of this research expects whether the multilayered fabric could be introduced in the suit.

Thermal conductivity of textile reinforcements for composites

Thermal conductivity data for dry carbon fibre fabrics are required for modelling heat transfer during composites manufacturing processes; however, very few published data are available. This article reports in-plane and through-thickness thermal conductivities measured as a function of fibre volume fraction ( Vf) for non-crimp and twill carbon reinforcement fabrics, three-dimensional weaves and reinforcement stacks assembled with one-sided carbon stitch. Composites made from these reinforcements and glass fibre fabrics are also measured. Clear trends are observed and the effects of Vf, de-bulking and vacuum are quantified along with orthotropy ratios. Limited differences between the conductivity of dry glass and carbon fibre fabrics in the through-thickness direction are reported. An unexpected trend in the relationship between that quantity and Vf is explained summarily through simple simulations.

A mathematical formula to find the wing band length of a bra to fit the comfort zone of the wearer

This work concerns on finding a formula of the length of a wing band within the comfort zone. Bra band elongation (BBE) test is one of the main methods that is being used to validate the comfort level of a bra bottom band when it is on the body. This test validates the suitable bra bottom band length, which is within the comfort zone for the wearer. However, BBE test by trial and error method is time-consuming and cost ineffective. Therefore, this research carries on an analytical method of obtaining a formula for the elongation of a wing band of a bra, which is assumed to be a rectangular thin plate. We obtain a new formula for the weighted elongation of the wing band using the Navier equation and compare the analytical weighted elongations and experimental elongation with different force values for the different bra sizes and for the different fabrics. With the weighted parameters, the model on elongation of the wing band fits with actual data and we provide specific different weighted parameters for different bra sizes to find the exact original length of the wing band of a bra.

Fabrication and characterization of chitosan/gelatin/thermoplastic polyurethane blend nanofibers

Polymer blending is a method to provide nanocomposite nanofibers with improved strength and minimal defects. Chitosan exhibits biocompatibility, biodegradability, antimicrobial activity, and wound healing properties. A combination of gelatin and thermoplastic polyurethane (TPU) blends was explored as a means to improve the morphological deficiencies of chitosan nanofibers and facilitate its electrospinnability. The morphology of the electrospun chitosan, chitosan/gelatin, and chitosan/gelatin/TPU blend nanofibers were characterized using scanning electron microscopy (SEM), while the miscibility and thermal behavior of the blends were determined using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy/attenuated total reflectance (FTIR/ATR). The optimum results were achieved in blend with 3 wt% chitosan, 8 wt% gelatin, and 5 wt% TPU, which resulted nanofibers with a mean diameter of 100.6 nm ± 17.831 nm.

Extended horn gears in 3D maypole braiding

This article presents the theoretical background for the arrangement of horn gears in maypole braiding machines in order to act as equivalent larger gears. The theoretical analysis is verified with numerical simulation and experiments. After review about the state of the art, an analysis of the process for one specific configuration of horn gears is given. This analysis demonstrates how a set of horn gears can be arranged to work as an equivalent to a larger one horn gear. The braiding equation is checked as remaining valid for such extended configurations, too. The theoretical result is verified using numerical simulation for all cases and practical validation for several variants. The theoretical rules give a clear extension of the current braiding knowledge and make the design of complex configurations of braiding machines more systematic and clear.

What drives consumers in China to buy clothing online? Application of the technology acceptance model

An enormous number of Internet users have made China a profitable e-commerce marketplace, and clothing is one of the most frequently purchased items. This study explores the predictors of consumers’ motivation to buy clothing online in China by extending the technology acceptance model. Data were collected via an online questionnaire, resulting in 504 returned responses. The results indicate that perceived usefulness has a significant effect on consumers’ intention to buy clothing online; however, no direct relationship between perceived ease of use and buying intention was found. Furthermore, perceived convenience, perceived money saving, and perceived time-saving can explain why consumers perceive buying clothing online as useful, and these perceptions have positive effects on buying intention. Additionally, the findings imply that fashion innovativeness and friend circles significantly influence consumers’ intention to purchase clothing online. This article discusses the results and provides recommendations for implication and future research.

Electrospraying poloxamer/(bio-)polymer blends using a needleless electrospinning machine

Electrospinning can be used to create nanofiber mats with high material purity and a large inner surface, applicable for medical or biotechnological filters, cell growth, and so on. Not each polymer which can be dissolved, however, can be spun in this way. Depending on the material, solution, and spinning parameters, especially on the molecular weight and the polymer concentration in the solution, either fibers or droplets can be formed. Both fibers and droplets are of technological interest for different applications. This article examines the possibilities of electrospinning or electrospraying poloxamer 188 (formerly known as Lutrol F 68, BASF, Germany) in combination with different biopolymers (dextran, gelatin, and agarose) as well as polyacrylonitrile (PAN) which belongs to the polymers spinnable from nontoxic solvents. Due to the similarity of the chemical structures of poloxamer and poly(ethylene glycol), a well-known spinning agent, and the relatively low molecular weight of poloxamer 188, it can be expected to work as a spraying agent. Our results show that electrospraying poloxamer/biopolymer blends is indeed possible, with the unexpected effect that for higher polymer concentrations, combining poloxamer 188 with dextran, fibers are formed additionally on parts of the substrate. Co-spinning poloxamer 188 with PAN, on the other hand, results in creation of a nanofiber mat whose morphology is mainly defined by the PAN content. The study shows that poloxamer can indeed be used as a spraying/spinning agent in electrospraying/electrospinning diverse biopolymers.

Effect of knit and print parameters on peel strength of hybrid 3-D printed textiles

The influence of knit fabric structure on the adhesion of three-dimensional (3-D) printed textiles was examined. 3-D printing was applied to different elastic knitted fabrics with different amounts of prestretch, typical for 4-D fabric construction. The quality of the bond was measured in terms of peel strength. Peel strength was measured by pulling the fabric at 180° from the printed plastic to delaminate the 2 and recording the 10 highest peak values observed during the test. The printed width, the ratio of fabric width of print width, fabric washing, and fabric structure were varied. The specimens were then evaluated for peel strength.

Neural networks and mechatronics for detecting carpet pile direction

Determining carpet pile direction is necessary in the manufacture of sample boards and when installing carpet because it is desirable for any shading effects to be homogenous. Depending on the style of the carpet, determining pile direction can be time-consuming and difficult. Two approaches to automating it are developed and tested in order to improve sample board production rates. Significant research has already been performed in the automatic detection of pile lay orientation in carpet and fiber orientation in nonwovens. These methods are insufficient for the present application because they yield the angle of a line parallel to the carpet pile but not the direction along that line in which the pile points. In this work, labeled carpet samples of varying styles are used to train and validate a convolutional neural network (CNN). These samples are also used to test an electromechanical solution. The CNN is shown to provide 100% accuracy when determining pile lay orientation and 93% accuracy when determining pile direction. The electromechanical method for determining pile direction is 65% accurate when used alone and 90% accurate when combined with prior knowledge of the pile lay orientation. These values fall short of the 99% accuracy of an expert operator detecting pile direction but compare favorably to that of a beginner.

Development of multifunctional cotton using fluorocarbon resin

An attempt has been made to develop multifunctional cotton fabric, possessing water repellent, stain repellent, shrink resistance and quick dry properties using fluorocarbon resin. The hydrophobicity of cotton fabric was determined by carrying out water repellency test, taking scanning electron microscopic photographs and measuring water contact angle. The durability of hydrophobicity of cotton was tested till 20 washes and found satisfactory. Oil repellency was determined employing hydrocarbons resistance test. The air permeability of cotton fabric was also determined keeping in view the impact on breathability of treated cotton and was found quite good. The untreated and treated cotton fabric was subjected to repeated domestic laundry condition, and shrinkage was measured, which indicated excellent shrink resistance behaviour because of its water repelling characteristic. This hydrophobicity of cotton also added to its quick dry behaviour even at low temperature and high relative humidity. The physical properties of treated dyed cotton fabric samples were compared with untreated, and no significant changes were observed in colour fastness to washing, rubbing, perspiration and light. The tensile and tear strength showed good retention even at higher concentration of fluorocarbon resin. This work is of great industrial importance for textile products used in home textiles. The textile industry can fetch more export earnings by doing multiple value addition using the same chemical. The work reported in the literature is about using fluorocarbon and developing water- and oil-repellent fabrics. In the present work, apart from water and oil repellency, shrink resistance and quick dry behaviour of cotton textile has also been established using same fluorocarbon because of hydrophobicity imparted to cotton.