Rheology of industrial polysaccharides — Theory and applications

Enzymatic processing of natural fibres: white biotechnology for sustainable development

The aim of this study was to examine the effect of fading methods such as sand-blasting, laser and washing on performance properties of denim products. In this study, on one type of denim fabric, f...

A Comparison Among Performance Characteristics of Various Denim Fading Processes

The laser engraving process allows short-time surface designing of patterns with precision, desired variety, size and intensity on a wide range of textile surfaces with minimum damage to the material. Because of this, it is possible that laser engraving applied to textile materials can make the fabric look faded and worn out without the use of any of the chemicals that are usually required in the conventional colour-fading process. In the present study, laser engraving was applied to denim fabric in order to evaluate its effect on some colour-related properties. Two laser process variables, namely, resolution and pixel time, were studied thoroughly. The laser power density was enhanced in response to the increased level of pixel time and resolution. Under the effect of high laser power density, a paler surface appearance was achieved for the denim fabrics with the largely reduced K/Ssum values, indicating that the amount of dye present on the denim fabric was decreased significantly. In addition, a green–yellow shade was observed in the denim fabric samples after laser engraving.

Technical study of the effect of CO2 laser surface engraving on the colour properties of denim fabric

Textile wet processing is an important step in textile production as it adds maximum value to the textiles by improving its aesthetics, comfort and functional properties. However, as the name indicates, a large amount of water is used as the medium which during the processing operations gets contaminated with unfixed dyes, chemicals and auxiliaries and is discharged in the end as effluent. The cocktail of chemicals present in this effluent makes it difficult to treat or biodegrade. It creates pollution problems and leads to further demand for good-quality water for processing. Natural textile fibres such as cotton need water and agrochemicals for growing, and petroleum resources are utilized for the manufacture of synthetic fibres. Energy is also needed at various steps of textile manufacturing process. Textile industry is thus water-, chemical- and energy-intensive industry and puts a lot of strain on global resources. Textiles now no longer just fulfil the basic human need of clothing; they have rather become a fashion statement. Rising income levels across the globe have led to manifold increase in world’s textile production and consumption in recent years. Average per capita world fibre consumption in the year 2014 was 11.4 kg and estimated that it may increase further in forthcoming years. Present times are therefore very challenging for textile processing industry as the quantum of textiles to be processed has greatly increased and the environmental regulations are getting stricter. As the economies of the countries improve, they move out of the textile processing activities, which then shift to lesser developed nations. This has resulted in lack of serious efforts on improving the sustainability of textile wet processing and poorer adoption of the available methods. The present status of textile wet processing technologies, various developments to tackle the sustainability issues and future prospects would be discussed in this chapter.

Challenges in Sustainable Wet Processing of Textiles

Denim trousers, commonly known as “blue jeans”, have maintained their popularity for many years. For the purpose of supporting customers’ purchasing behaviour and to address their aesthetic taste, companies have been trying in recent years to develop various techniques to improve the visual aspects of denim fabrics. These techniques mainly include printing on fabrics, embroidery and washing the final product. Especially, fraying certain areas of the fabric by sanding and stone washing to create designs is a popular technique. However, due to certain inconveniences caused by these procedures and in response to growing demands, research is underway to obtain a similar appearance by creating better quality and more advantageous manufacturing conditions. As is known, the laser is a source of energy which can be directed on desired objects and whose power and intensity can be easily controlled. Use of the laser enables us to cut a great variety of material from metal to fabric. Starting off from this point, we thought it would be possible to transfer certain designs onto the surface of textile material by changing the dye molecules in the fabric and creating alterations in its colour quality values by directing the laser to the material at reduced intensity. This study mainly deals with a machine specially designed for making use of laser beams to transfer pictures, figures as well as graphics of desired variety, size and intensity on all kinds of surfaces in textile manufacturing such as knitted—woven fabrics, leather, etc. at desired precision and without damaging the texture of the material. In the designed system, computer-controlled laser beams are used to change the colour of the dye material on the textile surface by directing the laser beams at a desired wavelength and intensity onto various textile surfaces selected for application. For this purpose, a laser beam source that can reach the initial level of power and that can be controlled by means of a computer interface; reflecting mirrors that can direct this beam at two axes; a galvanometer which comprised of an optical aperture; and a computer program that can transfer images obtained in standard formats to the galvanometer control card were used. Developing new designs by using the computer and transferring the designs that are obtained on textile surfaces will not only increase and facilitate the production in a more practical manner, but also help you to create identical designs. This means serial manufacturing of the products at a standard quality and increasing their added values. Moreover, creating textile designs using laser will also contribute to the value of the product as far as the consumer is concerned because it will not cause any wearing off and deformation in the texture of the fabric unlike the sanding and stoning processes. Another advantage of this system is that it gives a richer look to the product by causing the textile surfaces to get wrinkled and become three-dimensional by deformation as well as enabling you to create pictures and patterns on leather and synthetic fabrics by means of heat. As for the results of the study, the first step was to prepare 40 pairs of denim trousers, half of which were prepared manually and the other half by using laser beam. Time studies were made at every step of the production. So as to determine the abrasion degrees of the trousers in design applications, tensile strength as well as tensile extension tests were conducted for all the trousers.

Improving the appearance of all textile products from clothing to home textile using laser technology

This study investigated the differences between knitted fabrics made from compact and conventional ring-spun yarns. 100% cotton yarns, produced from the same cotton blend, were spun according to compact and conventional ring spinning principles in two different yarn counts and twist factors. Three different knitting structures, i.e., interlock, rib and single jersey, were produced from these yarns. The physical properties of these fabrics were investigated and compared with each other before and after the reactive dyeing process. When the results were examined, it was found that the hairiness of compact yarns was less and the strength and elongation percentages were higher, the fabrics produced with compact yarns showed less tendency to pilling and had a higher bursting strength. No statistical differences were observed with regard to spirality, weight, abrasion resistance, color efficiency and rubbing fastness of the fabrics produced with compact and ring-spun yarns.

The Comparison of Cotton Knitted Fabric Properties Made of Compact and Conventional Ring Yarns Before and After the Printing Process

Developing new designs by using the computer and transferring the designs that are obtained to textile surfaces will not only increase and facilitate the production in a more practical manner, but also help you create identical designs. This means serial manufacturing of the products at standard quality and increasing their added values. Moreover, creating textile designs using the laser will also contribute to the value of the product as far as the consumer is concerned because it will not cause any wearing off and deformation in the texture of the fabric unlike the other methods. In the system that has been designed, the laser beam at selected wavelength and intensity was directed onto a selected textile surface and a computer-controlled laser beam source was used to change the colour substances on the textile surface. Pigment printing is also used for designing in textile and apparel sector. In this method, designs are transferred to the fabric manually by using dyestuff. In this study, the denim fabric used for the surfacing trial was 100% cotton, with a weft count per centimeter of 20 and a warp count per centimeter of 27, with fabric weight of 458 g/m 2 . The first step was to prepare 40 pieces of denim samples, half of which were prepared manually pigment printing and the other half by using the laser beam. After this, some test applications were done. The tensile strength, tensile extension and some fastness values of designed pieces with two methods were compared according to the international standards.

The comparison of laser surface designing and pigment printing methods for the product quality

Laserle soldurma prosesi, denim kumaslarda eskitilmis gorunum kazandirmak icin kullanilan konvansiyonel fiziksel ve kimyasal islemlerle kiyaslandiginda, cok guclu bir alternatif olarak kabul edilmektedir. Bu calismada, denim kumaslarin soldurulmasi icin CO2 (10.6 µm) lazer kaynagi kullanilmistir. Lazerle islemin denim kumaslarin kopma mukavemeti, yirtilma mukavemeti, surtunme mukavemeti, maksimum ve kinematik surtunme katsayisi gibi ozellikleri uzerine etkisi arastirilmis ve optimum calisma kosullari belirlenmistir. Renk degisimi uzerine laserle soldurma isleminin etkisinin belirlenmesi icin, kumaslar yikanmis ve renk verimlilikleri, L a b degerleri ve sarilik indeksleri olculmustur. Hem renk hem de mekaniksel prosesler acisindan, denim kumaslarin lazerle soldurulmasi prosesinde 100 ve 150 µs puls surelerinin uygun oldugu belirlenmistir

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Arif Taner Özgüney

Papers

Improving the appearance of all textile products from clothing to home textile using laser technology

The Comparison of Cotton Knitted Fabric Properties Made of Compact and Conventional Ring Yarns Before and After the Printing Process

The comparison of laser surface designing and pigment printing methods for the product quality

Laser soldurma prosesi̇ni̇n deni̇m kumaşlari̇n renk ve mekani̇k özelli̇kleri̇ üzeri̇ne etki̇si̇ni̇n beli̇rlenmesi̇

The efficiency of washing agents in the post-dyeing removal of hydrolyzed reactive dye