Journal of Textiles and Polymers
Volume:2 Issue: 1, Winter 2014

Electrospunnano-fibrous webs have great potential in application in high efficiency air cleaning systems. In filtration process, the formation of cake on the filter media causes pressure drop thatincrease the filtration efficiency. Pressure drop of fibrous media is a function of cake characteristicssuch as porosity and air permeability. In this paper, the cake formation on nano-fibrous filter media is simulated using an image processing technique. The effects of particles’ characteristics, such as shape, size and configuration on cake porosity are investigated using the newly developed algorithm. Results of simulation show that the larger particles in air stream cause higher cake porosity.

Textile dyeing is a complicated process, so that quality of its final product is affected by the seemingly countless variables. As a consequence, diagnosing problems in this process is a very complex task. Troubleshooting process has been conventionally performed by human experts and the use of intelligence systems has been identified as a novel potential technology. Expert systems are computer systems that emulate and duplicate the behavior of experts for solving problems within a specific domain. Similar to a human expert, they can reason logically, make decisions and explain their conclusions. This paper reports on the development and evaluation of a dyeing diagnostic expert system (DDES) in the areas of cotton and polyester/cotton textiles and also compares construction methodologies of this system with the recently developed diagnostic expert systems in the field of textile coloration. The results reveal that the developed system can assist dyeing diagnosticians and other users by following an intelligent diagnostic method. It finds an optimal choice for handling human experts. Besides, it proposes an effective approach for integrating multiple experts’ opinions or sorting experts’ responses.

The seamless double layer fabrics are of special uses in industry. The strength of these fabrics is an important parameter due to different forces pushed on them. In the areas where there is a seam, the fabric has the lowest strength in comparison to other parts and this is the key point that shows the reasons of the importanceof strength of the seam in the industrial double layer fabrics. Present research provides a new method that increases the strength of the seam in double layer fabrics by shuttle less weaving machines. In this method, two layers of fabrics are joined each other during weaving, a hole is created in the joint of the two layers and the hole is filled by fillers with circular cross section. In fact, fillers with different diameters are employed for this purpose. The fillers with smaller diameters than the hole are used as half fillers and those with larger diameter are used as the full or complete fillers. The strength of these samples are then compared with those with holes and without fillers, two layer samples without hole (joined through the two layers), the sewed two layer samples and single layer fabrics. The results of finite element modeling indicate that the tensile strength of the seam increasesby adding fillers to the holes and increasing their diameters. Moreover, it is showed that, increasing of diameter of the hole does not affect the tensile strength of the seam for the samples filled with complete fillers.

Weight reduction is a chemical surface modification process with the aim of improving mainly the handle and touch of polyethylene terephthalate fabrics through hydrolysis, with the help of usually sodium hydroxide solution. The amount of weight reduction depends on processing parameters such as concentration of sodium hydroxide, treatment time and temperature. This paper describes the modeling of weight reduction of a polyethylene terephthalate fabric as a function of the three aforementioned parameters, using full factorial experimental design. Three levels were assigned to each parameter. After acquiring the model, the conditions leading to minimum cost for a given weight reduction percentage were found.

The main aim of this study is to present a new theory which shows the relationship between the warp knitted structures and some parameters of the fabric stiffness matrix. One of the important factors in this matrix is Poisson''s ratio that influence on the mechanical behavior of knitted fabric. The theoretical loop model based on geometry is used to investigate the tensile behavior of the fabric. The proposed loop model is basically based on the previously published assumption of fabric structure. This geometrically loop model is assumed to be two dimensional, but this model is applicable to analysis of the three dimensional structures as well. The specimen fabrics are produced with various two bar warp knitted fabric structures with changing the underlap length of the front or back guide bar (Tricot, Locknit, Reverse Locknit, Satin and Sharkskin) from polyester yarn. A uni-axial tensile tester is used for measuring the experimental work and geometrical parameters such as wale and course spacing of the fabrics are obtained during the extension. The model predicts the variation of Poisson''s ratio with longitudinal strain in all structures on the jamming point. Comparison between experimental and theoretical results for variety of fabric structures shows reasonable agreement between predicted and measured extension behavior of warp knitted fabric.

Polysulfone flat sheet membranes are fabricated by using solvent-nonsolvent exchange method. NMP is used as solvent and PEG 20000 as additive. Full factorial design is used to examine the individual and mutual impacts of parameters on the membranes. To that effect, the individual and mutual impacts of such parameters as polymer materials concentration, PEG 20000 concentration as well as non-solvent bath composition on the structure and function of membranes are studied. The structural analyses include porosity measurement and observation of SEM images. The membranes are subjected to pure water permeability for assessing their functions and operational evaluations. The effective parameters in the porosity analysis include, in terms of priority, coagulation bath composition, polymer concentration and PEG concentration while in pure water permeability analysis, PEG concentration overtakes polymer concentration.The results show that when PEG concentration in dope solution and NMP concentration in coagulation bath exceed than 9% (wt/wt) and 30% (wt/wt) while polymer concentration is respectively between 14 and 15% (wt/wt), the fabricated membrane would be suitable for microfiltration (MF) process.

Atheoretical analysis for the initial state of load-extension behavior in plain woven fabrics is presented. For this purpose, a new approach for geometrical modeling of woven fabrics consisting of its structure in inclined and float regions is developed which results in theoretical estimation of all the structural parameters of plain fabrics including its weave angle. Then, by applying the strain energy method and considering a virtual spring in the unit cell, a modified model for predicting the initial tensile modulus of plain woven fabrics is proposed. The results are shown better agreement with experimental data than previous models.