Mumtaz Hasan Malik

Statistical model for predicting the air permeability of polyester/cotton-blended interlock knitted fabrics

The aim of this study is to model the effect of knitting parameters on the air permeability (AP) of polyester/cotton interlock fabrics. Fabric samples of areal densities ranging from 105 to 654 g/m2 were knitted using yarns of three different polyester/cotton blends, each of the three different linear densities by systematically varying knitting loop lengths for obtaining different cover factors. It was found that changing the polyester/cotton blend ratio from 65/35 to 52/48 and 40/60 did not have a statistically significant effect on the fabric AP. AP sharply decreased with decrease in knitting loop length owing to increase in fabric areal density. Increase in yarn linear density (tex) resulted in a decrease in AP due to increase in fabric thickness as well as the areal density. It was concluded that response surface regression modeling could adequately model the effect of knitting parameters on the fabric AP. The model was validated by unseen data-set and found that predicted and actual values were in good agreement with each other with less than 5% absolute error. Sensitivity analysis was also performed to determine the relative contribution of each input variable on the AP of the interlock fabrics.

Development and characterization of three-dimensional woven-shaped preforms and their associated composites

Three-dimensional multilayer woven preforms are mostly used in high-performance composite applications due to their better in-plane and out-of-plane mechanical properties. The present study aims to produce and characterize multilayer flax yarn-based three-dimensional-shaped preforms and their corresponding composites. The T- and H-shaped three-dimensional woven preforms were prepared on conventional dobby loom using two types of weaving pattern, i.e., layer-to-layer orthogonal and through thickness orthogonal. Composites were fabricated using open mould technique. Peel strength of T- and H-shaped structures was investigated and compared with laminated structures. Mechanical properties of layer-to-layer-interlocked structures in T and H shapes were found better than TT and laminated structure, both for reinforcement and composite.

Effect of elastane linear density and draft ratio on the physical and mechanical properties of core-spun cotton yarns

The aim of this study was to investigate the effect of elastane linear density and draft ratio on the physical and mechanical properties of core-spun yarns. Twenty yarn samples were prepared on industrial scale in a spinning mill with two different yarn linear densities, each with different two elastane deniers and five draft ratios. It was found that core-spun yarn’s tenacity, elongation and hairiness are affected not only by the overall yarn linear density but also by the elastane linear density and the draft ratio. However, the effect of elastane linear density and draft ratio was not found to be statistically significant on the yarn mass variations and total imperfections, which are only affected by the overall yarn liner density. A statistically significant interaction for yarn elongation at break was found between the yarn liner density and the elastane linear density concluding that elastane linear density used in the core must be compatible with the overall yarn liner density for attaining the best yarn elongation.

Predicting the tensile strength of polyester/cotton blended woven fabrics using feed forward back propagation artificial neural networks

Tensile strength plays a vital role in determining the mechanical behavior of woven fabrics. In this study, two artificial neural networks have been designed to predict the warp and weft wise tensile strength of polyester cotton blended fabrics. Various process and material related parameters have been considered for selection of vital few input parameters that significantly affect fabric tensile strength. A total of 270 fabric samples are woven with varying constructions. Application of nonlinear modeling technique and appreciable volume of data sets for training, testing and validating both prediction models resulted in best fitting of data and minimization of prediction error. Sensitivity analysis has been carried out for both models to determine the contribution percentage of input parameters and evaluating the most impacting variable on fabric strength.

Modeling the effect of elastane linear density, fabric thread density, and weave float on the stretch, recovery, and compression properties of bi-stretch woven fabrics for compression garments

The aim of this study was to investigate the effect of elastane linear density, thread density, and weave float on the stretch, recovery, and compression properties of bi-stretch woven fabrics for compression garments. Fabric samples were produced using elastane core-spun cotton yarns both in the warp and weft. The elastane linear density, fabric thread density, and weave float size were used as input variables while fabric contraction, subgarment pressure, fabric stretch, and recovery were taken as response variables. Two different elastane linear densities, i.e. 44 and 78 dtex, two different thread densities, and three different weave designs, i.e. 1/1 plain, 2/2 z-twill, and 3/3 z-twill were used. The results of fabric samples were analyzed in Minitab statistical software. The coefficients of determinations (R-sq values) of the regression equations showed good prediction ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of bi-stretch fabrics to attain specific stretch, recovery, and compression properties.

Treatment of the textile industry effluent in a pilot-scale vertical flow constructed wetland system augmented with bacterial endophytes

A pilot-scale vertical flow constructed wetland (VFCWs) system was designed, implemented and operated for one year for the treatment of dye-rich real textile effluent. Brachiaria mutica was vegetated to develop VFCWs in which five different textile effluent degrading endophytic bacteria were inoculated. These bacteria were screened based on their dye degrading and plant growth promoting capabilities. The systems performance was evaluated by monitoring physicochemical parameters, nutrients removal, heavy metals reduction, detoxification potential, and persistence of endophytic bacteria in the plant rhizo- and endosphere. Although VFCWs were able to remove a majority of the pollutants from the wastewater, bacterial augmentation further enhanced the remediation efficiency. The system promoted an increase in dissolved oxygen up to 188% and, concomitantly, a substantial decrease in the chemical oxygen demand (81%), biochemical oxygen demand (72%), total dissolved solids (32%), color (74%), nitrogen (84%), phosphorous (79%), and heavy metals [Cr(97%), Fe(89%), Ni(88%), Cd(72%)] was recorded. Wastewater treated with VFCWs augmented with bacteria was found to be non-toxic and inoculated bacteria showed persistence in the root and shoot interior of B. mutica. Conclusively, VFCWs proved to be an effective methodology for treatment of textile effluent whereas its smaller size with high efficiency is an advantage for field-scale applications.

Integrated perspectives on the use of bacterial endophytes in horizontal flow constructed wetlands for the treatment of liquid textile effluent: Phytoremediation advances in the field

Constructed wetlands (CWs) have emerged as cost-effective and sustainable treatment systems for the remediation of industrial wastewaters; nevertheless, their potential has mostly been evaluated in laboratory-scale studies. Likewise, endophytic bacteria can enhance plant growth and reduce phytotoxicity under polluted conditions, but their application with pilot-scale CWs has rarely been evaluated. The present study aims to evaluate on-site performance of endophyte-assisted pilot-scale horizontal flow constructed wetlands (HFCWs) for the remediation of effluent from a textile industry. The HFCWs were established by planting Leptochloa fusca in the presence of three endophytic bacterial strains with dye degrading, and plant growth promoting capabilities. We found that the system was able to remove a significant proportion of both organic and inorganic pollutants. Maximum reduction of pollutants was observed in endophyte-augmented HFCWs, where the COD and BOD reduced from 493 to 70 mg l-1 and 190 to 42 mg l-1, respectively, within 48 h. Additionally, survival of endophytic bacteria in different components of the HFCWs was also recorded. Treated wastewater was found to be non-toxic and the inoculated bacteria showed persistence in the wastewater as well as rhizo- and endosphere of L. fusca. Accordingly, a positive impact on plant growth was observed in the presence of bacterial augmentation. The system performance was comparable to the vertical flow constructed wetlands (VFCWs) as high nutrients reduction was seen in the presence of this partnership. This pilot-scale study is a step forward toward the field-scale application of phytoremediation coupled with bacterial endophytes as a cost-effective means of on-site wastewater remediation. To the best of our knowledge, this is among the first pilot-scale studies on use of HFCWs for improvement in quality of textile industry effluent as most previous studies are limited either in the context of engineering or lack effective interplay of plant and bacteria.

Effect of sewing parameters and wash type on the dimensional stability of knitted garments

Abstract The aim of this research is to study the effect of clothing manufacturing parameters, that is, stitch type, stitch density, sewing thread type and washing type on the dimensional stability of single jersey knitted garment. Single jersey bleached fabric, made from Ne 32 cotton combed ring spun yarn, was used to make 32 medium size crew neck T-shirts selecting two levels of stitch type, stitch density, sewing thread type and wash type according to the experimental design. After constructing the garments, four critical measurements of each garment, that is, body length, body width, across shoulder and sleeve length were measured. The constructed garments were divided into two equal groups. One group was washed with water and the other group was washed using a detergent. After washing, drying and tumbling, the same critical measurements of each garment were taken and the percent shrinkage was calculated. Analysis of data was done on responses of output variables against the input variables using MINITAB. The results showed that three input variables: stitch type, stitch density and garment wash type have significant effect on all the output variables.

Effect of percentage of short fibers removed from cotton during spinning on the properties of dyed polyester/cotton‐blended knitted fabrics

The aim of this study was to assess the effect of the percentage of short cotton fibers removed during spinning on the properties of dyed polyester/cotton‐blended knitted fabrics. Combing of cotton fibers was done at 12% and 18% short fiber removal (noil%) before spinning into yarns with a polyester/cotton‐blending ratio of 52:48. The yarns were then knitted into 1 × 1 rib structure on a 20‐gauge, 20‐inch diameter double jersey machine. The knitted fabrics were pre‐treated and dyed with disperse/reactive dyes. After dyeing both the fabrics with 12% and 18% short cotton fiber removal, they were tested for their physical properties. It was found that the increase in the percentage of short fiber removal from 12% to 18% does not result in any significant enhancement of the fabric properties. Hence, a noil% of 18% is not justified for 52:48 polyester/cotton‐blended knitted fabrics. Savings of 6% in the cotton fiber may be made by keeping the noil% at 12%.

Mechanical and comfort properties of hydroentangled nonwovens from comber noil

Cotton is one of the most important commodity fibres and is widely employed in apparels. At present, the share of natural fibres in production of nonwoven fabrics is low and are used in opt applications. The cotton fibre is conventionally converted into woven and knitted fabrics by short staple spinning methods. The comber noil is short fibre waste produced when cotton yarns are combed. The aims of the current study were to employ comber noil for the preparation of hydroentangled cotton nonwovens at varying water jet pressures and conveyor speeds. The effect of these parameters was studied with respect to mechanical and comfort properties of the prepared fabrics. The results showed that these variables can help to manufacture fibrous assemblies with engineered properties, according to required application area.