Volume 19, Issue 3

Coir fibre is a non-conventional fibre extracted from the husk of coconut fruit and is abundantly available in tropical countries. Coir yarn is produced in the decentralised cottage industry. Increase in the demand for the coir fibre yarns for value-added applications has forced the coir yarn manufacturers to improve the existing coir spinning machine in different ways. In this study, the working principle of the existing coir spinning machine has been studied from the perspective of further improvements in production rate, yarn quality and spinning performance. Modifications have been made in the existing coir spinning machine in fibre feeding, opening and cleaning. There is improvement in the production rate of up to 20% with significant improvements in the yarn quality and spinning performance.

The aim of the paper is to assess the range and the mechanisms of transformations of the molecular structure and the physical microstructure of polyacrylonitrile (PAN) fibers produced by various manufacturers under the influence of thermal treatment in different conditions. The thermal treatments were carried out in different media (such as air, water, and steam), at various temperatures, and using different periods of treatment. Changes in the molecular structure were assessed using infrared (IR) absorption spectroscopy and evaluation of the differences in molecular cohesion energy of the fiber material during the dissolution processes. Changes in the fibers’ physical microstructure were investigated using densitometric, IR spectrophotometric, and X-ray diffraction methods; for assessment of both the reconstruction process of the paracrystalline matter of the fibers and the changes in the fibers’ total orientation, interferential polarization microscopy was used.

Supercritical carbon dioxide dyeing, a new type of anhydrous dyeing method, has a lot of advantages, mainly conservation of energy, prevention of pollution, reusability of dye, and many more. This study presents a viable method for the dyeing of an ultra-high-molecular-weight polyethylene (UHMWPE) fabric by using supercritical carbon dioxide (scCO 2 ) as a medium. Five hydrozono propanenitrile dyes that are functional colorants having antibacterial activity were applied for the dyeing of the UHMWPE fabric in scCO 2 at a pressure of 20 MPa and at temperature of 120°C. The dyeability of UHMWPE fabric under scCO 2 was evaluated by color measurement, whereby the color strength K/S was calculated. As the treating time and concentration of dye increased, the dyeability of the UHMWPE fabric displayed the tendency to continually improve. As decaline was added into scCO 2 as the cosolvent, we obtained higher K/S. Furthermore, color fastness to rubbing and sublimation of the dyed UHMWPE fabric were determined according to Japanese Industrial Standards (JIS) L 0849 2 and JIS L 0854, and the trend showed that the increase in fastness corresponded to the increase in duration of the treatment. The influence of scCO 2 dyeing on the mechanical properties of UHMWPE was also examined. Consequently, it was found that dyeing in scCO 2 containing decaline reduced the crystallinity of the UHMWPE fabric and the breaking strength decreased. The antimicrobial property of UHMWPE dyed with N′-(2-chloro-4-methylphenyl)-2-oxo-2-(p-tolyl)acetohydrazonoyl cyanide was tested against three different microorganisms, and the results have been reported.

In this paper, a novel kind of electromagnetic (EM) functional textiles is proposed, which show high-pass characteristics as they interact with EM waves. The periodically conductive woven fabric was designed, fabricated, and measured. Specifically, by means of unit cell model building and EM simulation, the theoretical S 21 (transmission coefficient) and S 11 (reflection coefficient) curves were obtained. A concrete sample was fabricated through weaving process, and its transmission characteristics were measured in the microwave anechoic chamber. The measured and simulated results were highly consistent, demonstrating the validity of design process. Compared with the aluminum foil paper sample, the S 21 values of fabricated sample were a little smaller, and the reason could be attributed to yarn crimp and surface roughness. The EM characteristics of fabricated sample under two different polarization modes were slightly different, which was due to the beating-up tension of weaving process. The work could offer new research ideas, and the related products have potential advantages over rigid plates on the account of textile characteristics.

Seersucker woven fabrics are increasingly used in the textile industry. Unfortunately, their popularity is limited due to the lack of standards and parameterization of their structure. Thus, the designer of the finished product (clothing, bedding, or decorative items) has problems with ordering a fabric with a specific structure and properties. In this context, it is necessary to parameterize them. This paper presents a method for measuring the surface geometry of seersucker woven fabrics using laser techniques. The surface geometry of the seersucker woven fabric was determined using adapted roughness parameters, such as Wz, Ra, and Rz, as well as by using a hypsometric map.

The embroidery process is one of the means of joining textile materials into a system, which is widely applied in the creation of products of special destinations. The development of the functionality of embroidery systems is indissoluble from high-quality requirements for the accuracy of the form of the element. In the embroidery process, the system of textile materials experiences various dynamic loads, multiple stretching, and crushing; therefore, the geometrical parameters of the embroidery element change. The objective of this paper was to analyze the widths of the different square-form closed-circuit embroidery elements and also to perform their analysis with the purpose to evaluate the embroidery accuracy of the embroidered elements. Test samples were prepared in the form of square-form closed-circuit embroidery elements of five different contour widths: 6 mm, 10 mm, 14 mm, 18 mm, and 22 mm. During the investigation, it has been determined that in most cases the contour widths of the five closed-circuit square-form embroidery elements were obtained, smaller than the size of the digitally designed element.

The detection of defects in yarn-dyed fabric is one of the most difficult problems among the present fabric defect detection methods. The difficulty lies in how to properly separate patterns, textures, and defects in the yarn-dyed fabric. In this paper, a novel automatic detection algorithm is presented based on frequency domain filtering and similarity measurement. First, the separation of the pattern and yarn texture structure of the fabric is achieved by frequency domain filtering technology. Subsequently, segmentation of the periodic units of the pattern is achieved by using distance matching function to measure the fabric pattern. Finally, based on the similarity measurement technology, the pattern’s periodic unit is classified, and thus, automatic detection of the defects in the yarn-dyed fabric is accomplished.

Knowing the reflection, transmission, and absorption properties of the yarns from which the woven fabric is made, prediction of a fabric’s UV-protective properties is simple. Using the geometrical properties of monofilament yarns and fabrics, which were determined optically, and following the cover factor theory, we have determined the areas of fabrics covered with no yarns, only one yarn, and two yarns. From a special selected set of high-module polyethylene terephthalate (PET) monofilament materials (e.g., fabrics), we have elaborated a method for determining the reflection, transmission, and absorption of yarns. By first defining the differently covered areas of fabrics, we were able to use them in a mathematical model for calculating and predicting the UV-protective properties of the fabrics. The calculated and measured values of the UV-protective properties of the selected test fabrics were highly correlated, with a correlation coefficient >0.98.

Thermal protective clothings are produced from multilayered textile materials. Fabric layers need to allow enough evaporation of perspiration, ventilation, and also thermal protection from fire. This study aimed to evaluate the effects of different fabric layers and their different combinations on the thermal properties of multilayered fabric samples. Three-layered fabric combinations were created using two types of outer shell fabrics, four types of moisture barrier fabrics with membrane, and two types of thermal barrier fabrics. Sixteen different fabric combinations that simulate three-layered thermal protective clothing were studied. As a result of the study, it was found that thermal and moisture comfort properties were significantly affected by different fabric layers.

This study examined the physical properties of polytrimethylene terephthalate (PTT)/Tencel/cotton air vortex yarns and the wear comfort of their knitted fabrics for high emotional garments. In fine yarn count, the initial modulus of the air vortex yarn was similar to the ring yarn because of the elastic property of the PTT fibers in the yarns. In particular, the thermal shrinkage of the air vortex yarns was higher than that of the ring yarns because of the sensible thermal shrinkage of the PTT fibers, which resulted in higher relaxation shrinkage of the air vortex knitted fabric than those of ring and compact knitted fabrics. On the basis of the wear comfort, the air vortex yarns are compatible with winter textile goods. The pilling of the air vortex knitted fabric was superior to that of the ring and compact yarns. The tactile hand of the air vortex yarn knitted fabrics was stiffer than that of the ring and compact yarn knitted fabrics. However, the harsh tactile hand of the air vortex knitted fabric was estimated to improve in the thinner fabrics by the low elastic modulus of fine yarn because of the PTT fibers in the air vortex yarns.

Polymer inclusion membrane (PIM) containing cellulose triacetate (CTA) as a polymer matrix and 2-nitrophenyl octyl ether (NPOE) as a plasticizer was developed. This membrane also contained di(2-ethylhexyl)phosphoric acid (D2EHPA) and tributyl phosphate (TBP) as the carriers of metal ions. The facilitated transport of lanthanum(III) from aqueous nitrate(V) solutions across PIM was studied. It was observed that metal ions were transported from the source phase into 2M H 2 SO 4 as the receiving phase. The transport through PIM with D2EHPA as the ion carrier was found as the more effective method of lanthanum(III) removal from the aqueous solution than transport through PIM with TBP as the ion carrier.

Attempts were made to find a more environmentally friendly technique for the printing of polyester (PET ) fabric, acting as an alternative to a usual disperse dye direct-printing process by using a plenty of water and salt and producing effluent contaminants. The low-emission printing technique includes the recipe containing disperse dye paste, synthetic thickener and the water-based silicone-modified acrylate and high-temperature curing process. The water-based silicone-modified acrylate for adhesive coating of polyester (PET) fibres was synthesized using butyl acrylate (BA), eight four methyl siloxane (D4), acrylonitrile (AN), styrene (St), methyl acrylic acid (MAA) and N-methylol acrylamide (NMA).The results showed that the silicone-modified acrylate adhesive could increase the percentages of dye fixation and the colour strength. The superior colour fastness (≥level 4) with the low-emission printing process was realized. The wastewater stream produced by the technique had a residual dye concentration of 2.62 mg/L, which was reduced by approximately 19 times that produced by traditional direct printing. The effluent wastewater drainage was reduced by 76.9%.