Identifying the Color Strength, Color Intensity, Chromophore Extent and Colorfastness Properties of Cellulosic Fabrics

Research Article

Adv Res Text Eng. 2020; 5(3): 1056..

Identifying the Color Strength, Color Intensity, Chromophore Extent and Colorfastness Properties of Cellulosic Fabrics

Alam SMM1 and Islam S2*

1Department of Textile Machinery Design and Maintenance, Bangladesh University of Textiles, Bangladesh

2Department of Fabric Engineering, Bangladesh University of Textiles, Bangladesh

*Corresponding author: Shariful Islam, Department of Fabric Engineering, Bangladesh University of Textiles, Tegjaon, Dhaka, 1208, Bangladesh

Received: July 01, 2020; Accepted: July 20, 2020; Published: July 27, 2020


The aim of this paper is to identify the color strength properties, color intensity properties, chromophore extent properties and colorfastness properties of cellulosic fabrics. The findings of this research established that cellulosic fiber like cotton reacted with natural sustainable dyes and produced permanent covalent bonds in between the fiber cellulose and the terminal reactive group and exhibited improved above stated color properties. The investigation was conducted on gabardine twill fabric using several sustainable dyes namely blackberry, cherry, orange and carrot. With the facility of required chemicals and auxiliaries, cellulosic fiber of cotton fabric responded against the reactive group of blackberry dye, formed stable covalent bonding and ensured enhanced color properties. The requisite experiments were initiated using the standard instructed by ASTM and AATCC as stated underneath the paper. Above stated color properties were experimented using Reflectance Spectrophotometer and FTIR Instrument by the scattering appearances and spectral reflectance of the samples as detailed beneath the paper. Infrared Radiation was ejected with the sustenance of FTIR instrument throughout the samples to provide spectral reflectance with peak values that certifies the existence of colorant or chromophore in the dyed cellulosic fabric with the above stated enhanced color properties. This research revealed potential ways for the scholars to further study in this field.

Keywords: Color strength; Color intensity; Chromophore extent; Transmittance; Cellulosic fabrics; Infrared radiation; Scattering characteristics


This paper has great importance on textile coloration and printing technology, as controlling colorfastness properties are must in this area. Different intellectuals worked regarding to this experiment at different times where literature review showed different results. Some of them were parallel and some were extensively contradictory. Due to the range of variables convoluted, if any dyes, chemicals or auxiliaries were changed during experiments, then the other color related properties of the fabrics were also changed [1].

Dyeing is the coloration process of textile materials such as fibers, yarns or fabrics. Dyeing is basically done in a solution that contains dye particles. After the coloration process is done, a strong bonding is happened in between the fibers and the dyestuffs [2]. Temperature, time, pH are the main parameters of dyeing. Dyeing particles are mainly two types such as natural and synthetic [3].

The dye diffusion is outstanding in fiber dyeing, hence the extent of dye applied to dye at this phase is also greater. Fiber dyeing is moderately more expensive than yarn, fabric, and garments dyeing [4]. The choice concerning the assortment of colors has to be made initial in the processing stages. Fiber dyeing is naturally used to dye wool and other fibers those are applied to make yarns with two or more colors [5].

Acid dyes are water solvable anionic dyes those are used to dye the fibers of wool, nylon, silk and reformed acrylic fibers exhausting neutral to acid dye solutions. It is basic dye, which is water solvable cationic dye that is basically used to dye acrylic fibers [6]. Direct dyes are generally applied in neutral or somewhat alkaline solutions around the temperature of boiling point, with the adding of either sodium sulfate or sodium carbonate and these dyes are applied to dye cellulosic fibers [7].

Mordant dye needs a mordant that develops the colorfastness properties of dyes against laundry, sun and sweat. Vat dyes are basically non-soluble in water and unable to color the fibers straightly [8]. The prime use of such dyes is to dye polyester fibers but they are also applied to dye nylon and acrylic fibers. To dye the fabrics with disperse dyes high temperature like 130°C is essential. The dyeing medium is always acidic [9].

Reactive dyes have chromophore groups those are attached with the substances, which are proficient enough to respond quickly with the substituent fibers [10]. The covalent bonds those attribute reactive dyes to sustainable fibers showed permanent colored shades. Disperse dyes are mainly formed to dye the cellulose acetate, which are not solvable in water [11]. Azoic dyeing is the process where insoluble azo dye is formed unswervingly inside the fibers, yarns or fabrics. The Sulfur dyes are produced to dye the cellulosic fibers, yarns or fabrics of darker shades [12].

Scouring is a laundry procedure on cotton fabric to eliminate natural polish and non-fibrous scums from the fabrics and any additional muddying or dust. Fabric is simmered in an alkali solution that creates soaps with free fatty acids [13]. Main chemical substance applied in the cotton scouring is sodium hydroxide that changes saponifiable fats and oils to detergents, liquefies inorganic substances and changes pectose and pectin into their solvable salts [14]. Additional scouring chemical is cleanser that is an emulsifying substance and eliminates soil and dust elements from fabric [15].

Harm can be caused to the cotton fabrics by sodium hydroxide, so decrease alkali materials in the discharge are better. It is noted that bio-scouring is familiarized in the scouring procedure in which organic agents are applied like as enzyme [16].

Bleaching improves the lightness values of fabrics by eradicating natural coloring and residual trace contamination from the cotton substances [17]. If the fabric needs to be colored a dark shade, then light bleaching is recommended and vice versa [18]. On contrary, for dyeing the light shades or bright white color, heavy bleaching is recommended. After completion of scouring and bleaching process, optical whitening agents are applied to increase the brightness of the fabrics [19]. Optical whitening agents or optical whitening agents are of three types like blue, violet and red [20].

Yarn dyeing is the process by which colors are added to the yarns at cone or package form. In skein dyeing process, the yarns are slackly coiled into skeins and then dyeing process is carried out [21]. The yarns have better dye diffusion, but the technique is leisurelier and relatively more costly. The technique of package yarn dyeing is relatively quicker, but the dye consistency may not be as decent as that of skein dyeing process [22].

In beam dyeing process, a punctured warp beam is used in its place of the spools used in package dyeing process. Space dyeing is applied to yield yarns with multiple colors and shades [23]. Basically, yarn dyeing gives satisfactory color fascination and diffusion for most textile substances [24]. Dense and extremely twisted yarns may not have good dye diffusion. This procedure is characteristically used when dissimilar colored yarns are applied in the construction of fabrics [25].

The process of fabric dyeing is known as piece dyeing, where fabrics are dyed after the fabrics have been made. It is popular, cheap and common method of dyeing fabrics of solid colors [26]. The decision concerning coloration can be made after the fabric has been made. Therefore, it is appropriate for rapid response orders [27]. Dye diffusion may not be good in denser fabrics, so yarn dyeing is occasionally used to dye dense fabrics in solid colors. Different types of dyeing machines are applied for piece dyeing [28]. The assortment of the apparatus is based on issues such as dye and fabric physiognomies, price, and the proposed end use [29].

Basically, printing is a process of localized dyeing. This is the system by which dyes or colors in a thick paste form are applied on a surface of fabrics [30]. In printing process, fibers are bonded with the printing paste [31]. Printing is also one type of dyeing but the main difference is, dyeing is done on the whole fiber, yarn or fabric, on contrary, printing is done on the localized or limited area [32].

Materials and Methods

Required fabric

Medium weight gabardine cotton fabrics were applied in this research for experimentation. Twill woven fabrics were used in this research as mentioned in Table 1.