Reeling
Also searched as: silk reeling, raw silk, filature, croissure, reeled silk, cocoon cooking
Reeling unwinds the continuous filaments of several softened silk cocoons at once and combines them into a single raw silk thread of controlled size, wound onto a reel.
In detail
Stifled cocoons are first cooked in hot water or steam to soften the sericin so the filament unwinds without breaking, and loose outer floss is brushed away to find each filament end. The reeler draws the ends of several cocoons together through guides. While still soft, the sericin acts as a glue as the thread passes through a croissure, where it is crossed on itself or with a second thread to press out water and bond the filaments into one compact strand. As cocoons run out, new ends are joined in to keep the thread size constant.
The science and numbers
Individual cocoon filaments average only about 1.5 to 3.5 denier, so thread size is built by combining filaments from roughly 2 to 20 cocoons, depending on the target. In common practice the reeling basin is held at around 40 to 45 C, with cooking done separately. The croissure gives cohesion by rubbing the composite thread rather than by adding lasting twist. The FAO reports total cocoon filament lengths of about 600 to 1,500 m, of which about 80 percent is typically reelable; the remainder becomes waste used for spun silk. Automatic reeling machines monitor thread size and feed new cocoon ends mechanically.
A practical example
A reeler working to a target raw silk size watches the thread as it forms. Filaments get finer toward the inner layers of each cocoon, so she adds a fresh cocoon before the combined size drifts low. That attention decides whether the finished fabric will later show uneven streaks or look uniform.
What to distinguish
Reeled silk is different from spun silk, which is carded and spun from short lengths out of broken or pierced cocoons and reeling waste. Raw silk from the reel still carries its sericin and must be degummed. Raw silk denier describes the combined thread, not one cocoon filament. Reeling also differs from throwing, the later twisting and plying of raw silk.
Origins and history
Reeling is as old as silk textiles themselves, beginning as hand reeling from a basin of hot water in China and spreading with sericulture. Equipment progressed from hand-turned reels to foot-powered reels and then to multi-basin filatures in mechanized silk factories, and later to automatic reeling machines. The general English word reel names a winding frame; in silk it specifically denotes this combined unwinding and joining step.
Related terms
Sources & further reading
- FAO: Silk reeling and testing manual, Chapter 6
- Central Silk Board (India): Processing of mulberry cocoons
- ProAgri: From silkworms to silk garments, Part 4.1, silk reeling methods
- FAO: Silk reeling and testing manual, Chapter 3
Technical references reviewed 2026-09-22. Examples are illustrative. Industry organizations and manufacturers describe their own fields; their references are not independent product endorsements. Figures are approximate and depend on the stated test conditions.