Concerning the existence of fractions of the sericin in raw silk

Abstract

Raw silk fibres consist of at least two proteins, silk fibroin and silk sericin. The latter forms a coating over the fibroin and constitutes 15 to 30% of the total weight of the raw fibre. In practical silk processing, the sericin is generally allowed to remain on the fibre until the fabric is ready to be dyed. In this way, it acts as a protective coating for the silk in the weaving or knitting operations.Removal of the sericin is usually accomplished with hot soap solutions. The results of numerous studies of this process led earlier investigators to a variety of con cepts concerning the state and properties of the sericin in the raw silk fibre. Some stated that the sericin is a single protein substance, whereas others claimed it to be a mix ture of proteins which they designated as sericins A, B, etc. The latter concept formed the basis for further claims concerning the desirability of retaining certain fractions of the sericin to improve some wltimate proper ties of the silk. As many of these claims we...