The quasi-yarn-dyed effect: triple dyeing of woven polyester/cationic dyeable polyester/viscose rayon blend fabrics by chemical treatments in the laboratory and on a pilot and an industrial scaleby Ilhan Özen, Adem Kurucu, Hakan Türksever

Coloration Technology


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The quasi-yarn-dyed effect: triple dyeing of woven polyester ⁄cationic dyeable polyester ⁄viscose rayon blend fabrics by chemical treatments in the laboratory and on a pilot and an industrial scale

Ilhan O¨zen,a,* Adem Kurucub and Hakan Tu¨rkseverb aDepartment of Textile Engineering, Erciyes University, 38039 Melikgazi, Kayseri, Turkey

Email: bS¸ark Mensucat Fabrikası A.S¸., Organized Industrial Zone, Atatu¨rk Cad. 4. Sok. No: 3 59500 C¸erkezko¨y, Tekirdag˘, Turkey

Received: 5 November 2010; Accepted: 15 September 2011

The aim of this study was to carry out triple dyeing of woven polyester ⁄ cationic dyeable polyester ⁄ viscose rayon blend fabrics with the required colour fastness and physical properties. The feel and final appearance of the fabric were achieved by partial removal of the viscose rayon moiety of the fabric through optimised causticisation treatments. The results of the triple dyeings obtained from laboratory and small-scale experiments were successfully scaled up in authentic processing equipment.

The final product, which has a yarn-dyed effect, readily satisfied the requirements related to the colour fastness and physical properties.


As is well known, there are two types of synthetic fibre products, the artifically made (viscose rayon and cellulose acetate) and the synthetic (polyester, nylon, acrylic and modacrylic, and polyolefin) [1]. The first, and nowadays still the most common, artificially made fibre is viscose rayon (CV). The demand for viscose fibres as a highquality fashion fibre has increased sharply over time. This is because of the versatility of viscose fibres in processing and applications, combining the best characteristics of both natural and artificially made fibres, which are: – wear comfort attributable to ‘breathing’; – good processing characteristics on modern textile and clothing machinery; – versatility of end product applications; – biodegradability [2].

Considering the production and usage of non-cellulosics, polyester fibres occupy the leading position among synthetic fibres because of their excellent textile properties, such as abrasion resistance, good mechanical properties, durability and good dimensional stability at a reasonable price [3,4]. Apart from various types of polyester fibre, such as poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT) and poly(trimethylene terephthalate) (PTT), modified types of polyester have also been produced thanks to wellestablished and highly developed polyester manufacturing technology. One of the most common modified polyesters that is used as a textile fibre is a PET copolymer containing a sodium salt of a dicarboxylic acid; for example, of 5-sulphoisophthalic acid. The acidic sulpho group allows the attachment of cationic dye molecules. This copolymer is called cationic dyeable PET (CD-PET) and provides PET ionic dyeability [1].

The combination of polyester and viscose fibres results in an optimum for textile applications because of their complementary properties, thus making this fibre blend the most important on the market; and this position will become even more prominent when it comes to satisfying the growing demand for textiles [4]. Dyeing of polyester ⁄viscose blends (yarns and fabrics) is a very complex process, which requires a very high input of labour, when dark shades are to be dyed at high quality.

The reasons for this can be found in the very different dyeing procedures of both fibres. Polyester is usually dyed with dispersion dyestuffs at 130 C and pH 4.5–6, while cellulosics are dyed using reactive dyes at 60 C, pH 6–10 and a high dosage of salt. Here, non covalently bound dyestuff has to be removed by soaping and ⁄or washing.

This requires that the single fibres have to be dyed one after the other in blends of polyester and viscose. Because of this complexity, related studies have focused on the shortening of the dyeing procedure of these blends. The polyester ⁄viscose rayon blended fabric was dyed in a single step by pretreating it with different solvents [5]. A system for simultaneously dyeing and texturing of polyester ⁄viscose blended yarn was reported using a single bath [6]. Apart from these studies, Lenzing AG (Austria) has developed a new type of viscose fibre that can be dyed under polyester dyeing conditions without the addition of salt and requiring only one rinsing step, thus significantly reducing the dyeing time of polyester ⁄viscose blends [4].

In the literature, it has also been cited that new areas of application were found in which the cellulosic parts of polyester blends were removed partially or completely, leaving behind the embroidered pattern of the synthetic fibre. In production of special types of embroideries, the pattern is sewn onto a cellulosic fabric with polyester doi: 10.1111/j.1478-4408.2012.00345.x ª 2012 The Authors. Coloration Technology ª 2012 Society of Dyers and Colourists, Color. Technol., 128, 153–159 153



Society of Dyers and Colourists yarn. The cellulosic fabric, which acts as the ground, is then removed subsequently by chemical treatments such as acid or enzymatic hydrolysis to yield the embroidery pattern [7–11].

Keeping in mind the developments in fibre blends mentioned above and the necessity of separate dyeing processes of each component, a different approach helps to reveal the pattern formation with the required handling, colour fastness and physical properties in woven polyester ⁄ cationic dyeable polyester ⁄viscose rayon blend fabrics by chemical treatments. In order to combine the reductive cleaning after dyeing of the polyester part and the chemical treatment for partial removal of the viscose rayon part, sodium hydroxide was used in this study. PET ⁄CD-PET ⁄CV blend fabrics woven with three different (PET, CD-PET and CV) yarns were used, and a yarn-dyed effect was obtained by chemical treatments after the dyeing procedure. The effects of the chemical treatment on the physical and colour fastness properties of the related fabrics have also been investigated in the laboratory, on a small scale and on a large scale.