WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
50.02 - Raw silk (not thrown). This raw silk is obtained by reeling the filaments from cocoons. In practice, since the filaments aves forming each cocoon are very h e , the raw silk (grbge) is obtained by combining sever filaments (usually 4 to 20) during the reeling process; these filaments adhere to ether as they are reeled because of the gum (sericin) with which they are covered. The raw silk laments are wrapped around themselves during reeling giving an even texture and section, assisting the drainage of surplus moisture and compensating for weaknesses in individual filaments; this operat~onfrequently results in the filaments acquiring a certain twist. However, the twist is only very slight and raw silk at this stage should not be confused with the single thrown yarns of heading 50.04. @ B Raw silk is usuaIly whitish, yellowish or sometimes greenish. It is also covered by this headin if discharged (i.e., the gum removed by hot soa y water, dilute alkalis, etc.) or dyed, but not i thrown. It is usually put up in long lengths ei er on conical bobbins, or in hanks (skeins) of varying weight and tied in a loose knot (slips). tg Thrown silk is excluded (heading 50.04). B
Silk GENERAL The General Explanatory Note to Section XI should be taken into account in reading the Explanatory Notes to this Chapter. P For the urposes of this Cha ter the term " silk covers not only the fibrous matter secreted by the Bom%yx mori mulberry eeding silk-worm), but also the products of the secretion of similar insects e.g., Bom yx textor known as wild silk. Among the wild varieties, so named because the pro ucmg worm has on y very rarely been domesticated, the most important is tussah silk obta~nedfiom a silk-wonn that feeds on oak. Spider silk and marine or byssus silk (the filaments by which certain shellfish of the Pinna family cling to rocks) are also classified in this Chapter. Generally speaking, this at its vmous stages of silk-worm gut. " ter covers silk, including mixed textile materials classified as silk, from the raw material to the woven fabric. It also includes