The cocoon pieces were added to the

The cocoon pieces were added to the solution and boiled without pressure for various lengths of time.
After the extraction, the solutions were filtered through a nonwoven filter to remove the remaining cocoon pieces. The cocoon pieces were then washed several times with warm water, dried in an oven at 50 ◦C for 3 days, and conditioned at room temperature for 12 h before measuring their weights. The degumming ratio was calculated using the following equation: