A. E. Körlü

An Investigation in the Use of Ozone Gas in the Bleaching of Cotton Fabrics

Ozone, composed of three atoms of oxygen, can be used to oxidize many inorganic and organic impurities. Because of its high oxidizing capacity, the opportunities and parameters of ozone gas use in bleaching of cotton fabrics were researched in this study. It was found that in a very short time cotton fabrics can be bleached if the water content of cotton-woven fabric was 60% and the pH of the water impregnated was 7. Moreover, ozonation at room temperature was shown to be more efficient than ozonation at high to medium temperatures.

Design parameter investigation of industrial size ultrasound textile treatment bath.

Design requirements for industrial size ultrasound bath for textile treatments have been determined. For this purpose, effects of sound pressure level, bath temperature, bath volume, textile material type and hydrophility degree of fabric were examined extensively. Finite element analysis (FEA) was used to investigate spacing and alignment of the ultrasound source transducers to reach effective and homogenous acoustic pressure distribution in the bath. It was found that textile material type, bath temperature and volume led to significant changes at sound pressure level. These parameters should be taken into consideration in designing of industrial size ultrasound bath for textile treatments. Besides, wettability of textiles is highly dependent to the distance from the transducers.

New Techniques in Cotton Finishing

The aim of this study is to investigate the effects of new advanced processes (ultrasound, ozonation, and ultraviolet) on cotton woven fabrics hydrophility and polymerization degrees, breaking strengths, whiteness, and desizing degrees. For this purpose, all trials were realized with water at 63-65°C by the aid of advanced processes. At the end of the experiments, it was noticed that advanced processes can be used in pretreatment of cotton fabrics. Ultrasonic treatment followed by ozonation gives sufficient whiteness degrees and hydrophilily values to the fabric. At the same time, treatment of cotton fabrics with new processes provides savings of thermal energy, water, and chemicals. Moreover, these processes are considered as green processes because they are ecological in certain conditions when compared with conventional processes.

Ultrasound-assisted wool bleaching

Bleaching is a finishing process to whiten the gray fabrics. During this process it is important to ensure the demanded results with minimum fiber damage by considering environmental aspects. As a result of this, the study focused on the wool bleaching which is also an important process for the quality of wool products. It was managed with and without ultrasound and it was found that via ultrasound better bleaching results can be obtained in addition to improvement in contact angles related to the hydrophilicity. It is expected that with the addition of ultrasound to bleaching process, same results obtained with conventional bleaching will be reached with lower treatment temperatures or lower treatment time which is now essential for the protection of environment.

The Bleaching of Soybean Fabric by Different Treatments Combined with Ozonation

This article is about bleaching of soybean fibers. Although the studies related to dyeing of soybean fibers have been found in the literature, little has been reported on the effect of bleaching. The natural color of soybean protein fibers is pale yellow or cream, and it is therefore usually necessary to bleach them to improve their whiteness. Different bleaching treatments combined with ozonation were performed in order to establish the effect on whiteness, yellowness, lightness, wettability, hydrophility, moisture sorption, and fiber damage properties of knitted soybean fabric. As a result of study, bleaching process combined with ozonation (ozonation + oxidative bleaching + reductive bleaching) supplied soybean fabric with a white appearance (highest whiteness degree), highest hydrophility, and minimal fiber damage.

Combination of Ozonation and Hydrogen Peroxide Bleaching for Linen Fabrics: Optimization of the Process Using Experimental Design Technique

It is well known that ozone can be used as a bleaching agent for cellulosic textile materials. In the context of this study, investigations were undertaken to optimize bleaching of linen fabrics using Box-Behnken Experimental Design. The bleaching process involved two distinct steps where linen fabrics were ozonated under different treatment times then the latter in a subsequent step were subjected to hydrogen peroxide bleaching under a variety of conditions. As a result of study, three optimum recipes were achieved and pretreatment with ozone for 15 min before peroxide bleaching supplies time and chemical savings.

Dye Removal From Textile Waste Water Through The Adsorption By Pumice Used In Stone Washing

Abstract Because the waste production is inevitable in almost all industries, the elimination of these wastes is a requirement in terms of environmental regulations and welfare of all the creatures in the future. In this study, the use of the waste pumice stones of a denim washing mill is intended to eliminate the pollutant by a waste material and obtain economic benefits by converting it to the adsorbent. The pollutants in the effluents obtained from three different localisations of waste water treatment system of the same factory were removed through the adsorption. The experimental studies were carried out in three different steps; characterisation of adsorbent before and after adsorption; adsorption isotherm studies and biological oxygen demand (BOD), chemical oxygen demand (COD) measurements. Characterisation studies showed that the waste pumice has almost the same structural properties with unused one except the existence of some organic residues coming from washing process. The results of adsorption studies conducted at the adsorbent concentrations changing from 5 to 35 g/l revealed that the decolourisation was initial dye-concentration dependent. According to the BOD and COD measurements, the supernatants obtained at the end of adsorption could be assumed as somewhat polluted and this result indicates that the organic impurities other than indigo were also removed through the adsorption.

Yellowing tendency of ozonated cotton fabric and ways to prevent this undesirable side effect

This paper provides a general framework for studying the yellowing tendency of ozonated cotton fabric. Yellowing tendency of ozonated cotton fabric and ways to prevent this situation was examined extensively. For this purpose, five different treatments (hot/cold rinsing, washing, reductive washing, catalase treatment) were performed after ozonation. It was found that performing any kind of treatment was significantly important for preventing yellowing of ozonated cotton fabric during storage.

Effects of different pretreatment processes on viscose fabrics in different types and properties

Abstract In this study, the effects of different pretreatment processes on the properties of viscose fabrics (sulphur content, whiteness degree, weft yarn breaking force, crystallinity and fiber surface) and on the color efficiency and repeatability of the prints have been investigated. For this purpose, viscose fabrics obtained from different sources and containing different amounts of sulphur were causticized, bleached, and reductive-washed. After impregnation with urea, fabrics were printed with two reactive dyestuffs having the same reactivity, but different molecular sizes. Color values of both dyes were measured and fastness was tested and compared in order to observe the effects of different pretreatment processes. Different methods of sulphur analysis were also investigated and tested to determine the sulphur content of the fibres. Among these methods, the lead acetate method, which is a subjective evaluation system, has been selected as the most appropriate for practical working conditions of the plants, and a sulphur scale was formed according to this method. Accuracy of the scale was also confirmed by elemental analysis (CHNS–O) method.