Effect of urea on raw silk degumming with papain

Urea was compounded with papain and resulting product was used for the degumming of raw silk. The raw silk was placed separately in water,papain,urea,and urea / papain solution for degumming treatment under certain conditions,and the effect of urea on the degumming of raw silk was examined by the weight loss percentage of the raw silk. The results indicated that the weight reduction rate of the raw silk was low when urea was used alone in the degumming; and when urea was used in combination with papain as degumming agent,the urea had no toxic effects on papain. As the concentration of the urea was greatly enhanced in the presence of papain,the amount of enzymes required for degumming could be obviously decreased. Enzymatic degumming could be carried out over a broader temperature range. Since small amount of urea exhibited unnoticeable weight reduction effect when used in combination with papain for degumming of raw silk,only large amount of urea could bring into fully play. When urea is compounded with papain for degumming,it is only possible when its dosage is greatly reduced and therefore further research is needed.