Degumming of Silk Yarn with Protease (Alkalase) and Comparing it with Keliab

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.