Surface modification of wool/nylon blended fabric was carried out with protease enzyme to improve their dyeabilities to natural dyes. Cutch (Acacia Catechu) was selected and used in this study. The effect of enzyme concentration on the dye uptake (K/S) was studied at fixed treatment conditions: pH, temperature and treatment time.
The obtained results of K/S were compared to the corresponding values obtained for the control samples which were dyed without enzymatic pretreatment. Treatment with protease was found to increase the absorption capacity of both wool and nylon fibers to the natural dye leading to higher K/S compared to untreated samples.
The dyeing parameters were also studied including, dyeing pH, temperature, time and mordant concentration along with concentration of dispersing agent. The colour strength was observed to increase by increasing the pH of dye bath, temperature and concentration of dispersing agent, which may be attributed to increasing dye solubility and as a result the rate of diffusion and penetration of the dye inside the fibers of both nylon and wool.
Fastness properties to washing, perspiration and light were also assessed and were observed to range between good and excellent.
In this work an attempt has been made to optimize the process of dyeing wool fabric with Kamala natural dye, firstly by enhancing the colour strength obtained via treating wool with Safflower enzyme extract.
The noticeable increasing in colour strength as a result of bio-treatment with Safflower extract is attributed to the enzyme extract which contains mainly lipase and protease enzymes which improve the dyeability of wool fabrics. All the parameters that may affect the bio-treatment process were studied in details, also the dyeing parameters such as dye concentration, pH value of the dyeing bath; both dyeing temperature and time were studied to determine the optimum conditions for both the treatment and dyeing processes.
In order to develop an eco-friendly natural dyeing process that is compatible with the environment, fixation process was made by using pomegranate as a natural mordant for the Kamala natural dye instead of the artificial ones. The factors affecting the fixation process with pomegranate natural mordant were investigated to conclude the optimum conditions of fixation stage.
It is obvious from this study the possibility of having bright deep colour from Kamala natural dye on the bio-treated wool fabric with good fastness properties that will match with the recent demands of using eco-friendly materials to be attuned with the environment.
Cotton fabrics were cationized with a cationic agent (Chromatech9414) then dyed with Brazilwood natural dye using ferric chloride as a mordant in one bath at three stages by exhaustion method. This process successes to impart cationic sites on cotton fabrics surface which improve its substantivity to natural dye beside save energy and water. The effect of (Chromatech9414) concentration on the nitrogen content was studied. Factors affected the dyeing stage such as dye conc., pH value, temperature and time of dyeing were investigated.The effect of cationic agent concentration and ferric chloride conc. on the colour strength of dyed cotton fabric with Brazilwood natural dye were observed. The best results were obtained at 8% Brazilwood natural dye, pH6 , 60 min., 60oC for dyeing stage at 6%(Chromatech9414) and 8g/l ferric chloride. The effect of mordant, dyeing pH and cationic agent concn. on the colour hue were also investigated .The wettability and the fastness properties of dyed samples were assessed.The changes in the fiber surface, by cationization ,were evaluated using scanning electron microscopy(SEM).