Quarterly Scientific-Research Goljaam

The influence of urea as an additive in dyeing of wool with madder was evaluated in this work. A different concentration of urea was applied on wool yarns before, during and after dyeing of samples. The treated samples were tested for dye absorption at different time, wicking, sinking, wash and light fastness and surface morphology by scanning electronic microscope. The results show that urea is an effective additive in dyeing of wool by madder by increasing the dye absorption. Adding of urea ranging 50% to 250% on weight of fibers leads to swell the wool fibers however, increasing the urea percent to 300% may damage the fiber surfaces and reduces the fiber strength.

One of the pre-treatment processes on silk is degumming that has much influences on other processing. There are various degumming methods and each one has its own advantages and disadvantages. In this research protease (Alkalase) and Keliab (remaining ashes of "Oshnow" plant obtained from Qom, Yazd and Kashan) used as environmentally friendly compounds for degumming of silk. Different concentration of enzyme with soda ash and surfactant and also Keliab were examined. Some properties of degummed samples such as weigh loss, strength, lightness and whiteness were tested and surface morphology also was observed by SEM. The degummed yarns then dyed with madder, using two types of mordant namely stannous chloride (SnCl2) and aluminium-potassium sulphate AlK(SO4)2. The color coordinates L*a*b* and washing fastness and light fastness of samples were evaluated. The results showed that weigh loss percentages, strength and whiteness of samples varied due to degumming with Alkalase and Keliab. However, washing fastness and light fastness of madder dyed samples were acceptable.

UV irradiation was known as an important factor for skin cancer and also textile fibers and dyes degradation. UV rays have high energy photons degrading dyes and fibers causing fading and rotting of textiles when they are exposed to sunlight. The sun blocking properties of a textile are enhanced when a dye, pigment, delustrant, or UV absorber is present which absorbs UV radiation and releases heat. They block the transmission of UV and inhibit the dye and fiber exposure. In this study, natural dye of madder with different mordants and two organic acids including: tannic acid and citric acid were selected for dyeing wool. Impacts of tanninc acid and madder on UV transmission were investigated. Also the effects of madder on protecting fabrics against UV were determined by measuring their tensile strength. The results indicate that tannic acid has positive influences on blocking UV and even increasing the tensile strength. The results also reveal that silver nitrate and copper sulphate are the best UV blocking among others. Finally, the wool fabric sample treated with silver nitrate and dyed with madder along with tannic acid exhibits the highest protection against UV.