Post Cocoon Processing

Once cocoons are spun, extracting usable silk thread is a distinct process called post cocoon processing, made up of stifling and reeling. Cocoons are gathered roughly 8–10 days after spinning began, and are first exposed to steam or dry heat — this is stifling, and it kills the pupa inside so the moth cannot emerge later and break the continuous silk fibre by chewing its way out. The cocoons are then soaked in very hot water (95–97°C) for 10–15 minutes in a process called cooking, which softens the natural gum binding the silk threads together; while still in hot water, the loose thread ends are caught by hand and wound together from several cocoons at once on spinning wheels called charakhas, producing reels of raw silk — this final unwinding step is reeling. Only about half of each cocoon's silk is actually reelable as continuous thread; the rest becomes silk waste that is respun into spun silk. The raw silk is then given further treatments to bring out its characteristic lustre. A more recent innovation, developed by Singapore's Institute of Materials Research and Engineering (IMRE), sidesteps the traditional post-production dyeing pro …