Degumming
The A. atlas cocoons were separated into three layers by hand. The three layers were separately degummed us- ing ethylenediamene and sodium carbonate. Cocoon layers were treated in 10 % ethylenediamine and 0.5 % sodium carbonate for 1 h at 80 °C with a solution to co- coon ratio of 20:1. Later, cocoons were washed in water and retreated in the ethylenediamine and sodium car- bonate solution at 80 °C for 15 min to complete the de- gumming and obtain loose fibers. Degummed silk was thoroughly washed in water and dried under ambient conditions.