5509.41.00.10 - Of polyvinyl alcohol (PVA) fibers (604)

This HTS classification, 5509.41.00.10, specifically designates single yarns of synthetic staple fibers that contain 85 percent or more by weight of synthetic staple fibers and are not put up for retail sale. The defining characteristic of this category is that the yarn is composed of polyvinyl alcohol (PVA) staple fibers, as indicated by the "(604)" designator. These are yarns intended for further processing into textiles rather than for direct consumer use.

This classification is distinguished from its sibling category, 5509.41.00.90, which covers "Other" single yarns meeting the same criteria (85% or more synthetic staple fibers, not for retail sale) but are not made of polyvinyl alcohol (PVA) fibers. Therefore, the material composition is the primary differentiator at this level, directing PVA fiber yarns to this specific subheading.

As this is a leaf node within the HTS structure, there are no further subcategories for this specific classification. The detail provided at this level is intended to capture the distinct nature of single yarns made from PVA staple fibers within the broader context of synthetic staple fiber yarns.