Modelling of surface roughness based on geometrical parameters of woven fabrics

A novel model has been developed for the surface roughness evaluation of woven fabrics, based on fabric geometrical parameters. The model is developed based on the properties of twenty five groups of woven fabrics consisting of five various weave structures and five different weft densities. The output of the model is validated through a set of subjective roughness pair-comparison tests. The model output is found to be in accordance with the roughness scale value which is obtained from subjective tests, to a reasonable extent. The statistical analysis of roughness results shows that the effect of fabric structural parameters such as weave structure and weft density is significant in the confidence range of 95%. This model can be utilized for the prediction of the roughness behavior of various types of woven fabrics. Bearing in mind the influence of fabric surface roughness on the comfort and aesthetic properties of cloths, the usage of the model is a guide for selecting the suitable fabric for various end uses

Measurement of yarn density in woven fabrics using fringe projection moiré techniques

Fringe projection Moiré, a novel, accurate and fast technique with high repeatability, has been developed in order to measure the yarn density in woven fabrics. In the experimental set-up, collimated laser beams illuminate a Ronchi grating to be projected on a fabric. In case the density of projected lines and fabric becomes the same, the desired moiré pattern is observed on the fabric. As a result, the measurement of the distance between grating and fabric can guide us to find out fabric yarn density by using simple equations. In this regard, twenty five groups of shirting woven fabrics consisting of five weave structures and five different weft densities have been tested. The results show that there is a high correlation (R2 =0.9932) between the data obtained from the new and the conventional methods

Experimental and theoretical investigation of hollow polyester fibers effect on impact behavior of composites

In this paper, the effect of utilizing hollow polyester fibers as reinforcement in composite material in comparison with solids is investigated. The three-point bending impact test is carried out to study the impact behavior and mode of failure of composites. After that, the finite element method is used for theoretical investigation and modeling the behavior of two different reinforced composites during impact tests. It was found that the fiber–matrix interface failure is the most dominant mode of failure and the crack was initiated at the middle of the bottom surface of composites. It was also found that the impact resistance of the hollow fiber composite is more than the others. Theoretical results showed good correlation with experimental results as well. The stress distribution and the maximum value of strain energy density was found as two factors which lead to improvement in the impact behavior of hollow fiber composites

Improvement of Impact Damage Resistance of Epoxy- Matrix Composites Using Ductile Hollow Fibers

ABSTRACT Fiber reinforced polymer structures typically respond very poorly to transverse impact events. In this study, some experimental investigations are performed on the low velocity impact behavior of unidirectional hollow, solid and hybrid (hollow/solid) polyester fiber composites. The materials are fabricated in a curved shape using filament winding method. The impact tests are applied on the simply supported specimens by a drop weight impact test apparatus at five levels of energy. To present a proper comparison on the results, the various densities of the materials are considered as normalizing coefficients. It is observed that in the hollow fiber composites cracks appear at an appreciably higher amount (93%) of impact energy than the solid ones

Drug release profile in core-shell nanofibrous structures: A study on Peppas equation and artificial neural network modeling

Release profile of drug constituent encapsulated in electrospun core-shell nanofibrous mats was modeled by Peppas equation and artificial neural network. Core-shell fibers were fabricated by co-axial electrospinning process using tetracycline hydrochloride (TCH) as the core and poly(L-lactide-co-glycolide) (PLGA) or polycaprolactone (PCL) as the shell materials. The density and hydrophilicity of the shell polymers, feed rates and concentrations of core and shell phases, the contribution of TCH in core material and electrical field were the parameters fed to the perceptron network to predict Peppas constants in order to derive release pattern. This study demonstrated the viability of the prediction tool in determining drug release profile of electrospun core-shell nanofibrous scaffolds. (C) 2013 Elsevier Ireland Ltd. All rights reserved

Modelling of surface roughness based on geometrical parameters of woven fabrics

43-50A novel model has been developed for the surface roughness evaluation of woven fabrics, based on fabric geometrical parameters. The model is developed based on the properties of twenty five groups of woven fabrics consisting of five various weave structures and five different weft densities. The output of the model is validated through a set of subjective roughness pair-comparison tests. The model output is found to be in accordance with the roughness scale value which is obtained from subjective tests, to a reasonable extent. The statistical analysis of roughness results shows that the effect of fabric structural parameters such as weave structure and weft density is significant in the confidence range of 95%. This model can be utilized for the prediction of the roughness behavior of various types of woven fabrics. Bearing in mind the influence of fabric surface roughness on the comfort and aesthetic properties of cloths, the usage of the model is a guide for selecting the suitable fabric for various end uses

Measurement of yarn density in woven fabrics using fringe projection moiré techniques

203-207Fringe projection Moiré, a novel, accurate and fast technique with high repeatability, has been developed in order to measure the yarn density in woven fabrics. In the experimental set-up, collimated laser beams illuminate a Ronchi grating to be projected on a fabric. In case the density of projected lines and fabric becomes the same, the desired moiré pattern is observed on the fabric. As a result, the measurement of the distance between grating and fabric can guide us to find out fabric yarn density by using simple equations. In this regard, twenty five groups of shirting woven fabrics consisting of five weave structures and five different weft densities have been tested. The results show that there is a high correlation (R2 =0.9932) between the data obtained from the new and the conventional methods

The application of Cd Se/ZnS quantum dots and confocal laser scanning microscopy for three-dimensional imaging of nanfibrous structures

This paper reports a fast, accurate, and non-destructive three-dimensional imaging approach based on using quantum dots and confocal laser scanning microscopy to get three-dimensional images of internal pore structure of the nanofibrous materials. A practical method of making the fiber fluorescent using quantum dots was applied before three-dimensional imaging by confocal laser scanning microscopy. Fibrous scaffolds with different porosity parameters produced by electrospinning and their three-dimensional pore structure was evaluated by this approach. Furthermore, the introduced approach can be used to measure the pore interconnectivity of the scaffold<br /