5402.52 - Of polyesters:

This HTS category, 5402.52, encompasses synthetic filament yarn that is not sewing thread and is not packaged for retail sale. Specifically, it covers single polyester filament yarns with a twist exceeding 50 turns per meter. This designation applies to polyester yarns that are not monofilament and are intended for industrial or manufacturing use, such as in the production of fabrics, ropes, or other textile articles.

Distinguishing this category from its siblings is crucial for accurate classification. Unlike 5402.51, which covers nylon or other polyamide yarns, or 5402.53, which pertains to polypropylene yarns, 5402.52 is exclusively for yarns derived from polyesters. Furthermore, it differentiates from 5402.59, which serves as a residual category for other synthetic filament yarns not specified elsewhere. The defining characteristic here is the polyester composition.

Within 5402.52, two subcategories exist to refine classification based on specific physical attributes. The first, 5402.52.10.00, applies to wholly polyester yarns meeting precise specifications: a decitex measurement between 75 and 80, and containing exactly 24 filaments. The second subcategory, 5402.52.90.00, covers all other polyester filament yarns that do not meet the stringent criteria of the first subcategory, providing a broad classification for the remainder of polyester yarns under this heading.